Stacked Advents?! Is It Just A Myth??

[@FredPinkertonIII]

Hi Kevin, I was the Audio Product Manager at Advent from 1975 to 1981 and at Boston Acoustics from 1981 until about 1987 (hazy on that date). I am NOT the designer of early Advent speakers or any of the Boston Acoustics speakers. That was Henry Kloss in the case of the original Advents and Andy Kotsatos for some Advents and all Boston Acoustics speakers. But I was present for the development on every speaker after the original Advent and for all the Boston Acoustics models during my tenure. There's some content on your channel about these brands, so I'll comment on anything I think is relevant. I haven't listened to the video yet (sorry). I'll do that after finishing this comment. After looking at the stacked Advents in the background of the video, I want to comment that the original Advent Loudspeaker requires the grille in place to work properly. Notice the tweeter is not mounted flush with the face of the front baffle. It's about 3/4" above it. And the grille is mounted on stand-offs. This is so the smooth surface of the grille panel is flush with the tweeter. That masonite square around the tweeter creates an acoustic seal with 2.5 inch (?) hole in the otherwise solid top half of the grille panel. Without the grill panel in place, the bottom half octave of the tweeter drops about 3 dB over a half-octave or so (1200Hz to 1600Hz). The speakers don't sound immediately "bad" with the grille off... but they don't sound like Advents and avoidable narrow bandpass drops in the midrange are simply wearing to hear over time. BTW, I was also part of the BA A400 design group.

[@Chiefonenut]

I picked up some BA A200's at the local thrift store, 20 bucks for the pair. Refoamed them and WOW. What a sound stage!

[@FredPinkertonIII]

Hand built in east Boston Massachusetts, in the shadow of planes landing at Logan International Airport. The whole point of the large front baffle was to make sure the listener heard the same tonal balance--independent of room placement and across a wide angle in front of the speakers. Imagine hauling a pair of them around with you in checked baggage visiting hifi stores across the USA and Canada. @@Chiefonenut

[@billmellater]

This is what I come here for. Long lost facts from an OG or that have been passed down generations be it cars, electronics, historical...... It's a shame the op(as of the time of my reply) hasn't collected this info to keep it alive. I'm only assuming he hasn't due to the fact that he hasn't responded.

[@Michael-y3l9m]

Fred thats rock n roll man! They got it right in the early to mid 70's for sure, speaker and cabinet design,uk goodmans,cellestion ,kef, wharfdale, and quad and the likes so a pleasure to be able to reply to an Audio wizard from bk in the day.

[@FredPinkertonIII]

@@Michael-y3l9mBecause "stereo hifi" was THE primary home musical entertainment medium from 1965 to 1990, you could find quite a few excellent, affordable speakers. As I've mentioned previously on this site (I think it was this site), my current recommendation for "great bookshelf speaker to purchase now" is the Dynaco A25. The parts were durable--no urethane foam to disintegrate. But more to the point, this model had very smooth frequency response--even from a 35 year old example that I witnessed being measured while at Cambridge SoundWorks. It's easy to fall in love with a speaker if it makes your "current" favorite music sound appealing. But a speaker with flat frequency response will always end up being the best long term choice. Another advantage of the A25 was that they made a million of them (or so). So they are easier to find than otherwise excellent UK models.

[@jemsmay2167]

Did this in college in the late seventies combining my pair with my roommates speakers. Definitely bigger fuller sound and great party setup. probably more that we needed in our apartment but fun none the less. Powered them with a Kenwood receiver that had plenty of power, and fed them mostly cassette tape from my Akai player (pro tip, we put a thin layer of foam between the speakers). Fast forward 40 some years, the advents are in the living room, driven by the same Kenwood (and a new turntable). Rock on.

[@JonPaul]

Really, you still have the same speakers\Kenwood and they are now in your living room 50 years later? That is truly awesome to hear, very impressive. Rock on!

[@jemsmay2167]

@@JonPaul speaker woofers refoamed about 5 years ago, receiver reworked (LED!) and recapped last year by Just Audio in Baltimore. Turntable is Fluance 85 with ortofon blue, mostly playing rock, folk, jazz albums from the 60s thru early 80s. I agree with this review, the speakers sound special good with live recordings and jazz. I have KEF, marantz, schiit equipment in another room, but listen to the advents more often. The sound is not “better” but it is more familiar, fits the music I like and makes me smile every time!

[@markmcminn5100]

I still have my High School Technics SA303 reciever.

[@josephcangelosi4414]

Hi Kevin, I discovered your channel through Randy (Cheap Audio Man). Love your outstanding and informative videos. I own vintage and current equipment. My vintage gear I bought brand new in 1976 and still use; Yamaha CR-600, Walnut large Advents (new metal cased woffers with new soft dome tweeter). B&O Beogram 1900 turntable with a 20EN cartridge still works. I truly enjoy your articulate, well thought out videos. Keep up the great work! Joe C.

[@stephenpowers5653]

I have stacked Advents! I play them through several different receivers & amplifiers. I own several sets of speakers and keep coming back the the Advents.❤

[@johnmichael1584]

In the late 70s I worked for Advent Corp. as a "District Sales Representative" before they fired the direct sales force and hired independent rep firms across the country. I also worked in a retail store in the early 70s and sold a lot of Advent products, including the 201 Cassette, Advent 300 Receiver, the little 400 radio, the VideoBeam and lots of loudspeakers. In 1974 my living room was graced by a pair of stacked Advent Loudspeakers powered by a Pioneer SA9100 integrated amp with a Phillips 212 turntable as the source. Your video brings back memories and I can see you have the original style woofers in your video. There were several changes in production during the life of the Advent Loudspeaker, and lots of arguments about the performance of later versions. The story behind the woofer was that in order to get the pitch of the diaphragm steep enough to keep it from flexing and coloring the lower midrange, they had to use a basket for a deeper 12" woofer even though the cone was really sized for a 10" diameter. That's the reason for the pressed fiber ring in the earlier production. Later production changed to a different stamped basket. The tweeter voice coil was never changed, but ferrofluid was introduced to help keep it cool and there were a lot of critical comments claiming it altered the sound. The last change I know of was to use open cell foam instead of fiberglass to dampen the inside of the cabinet. They did change the tweeter eventually, to what was marketed as the "DIRECT REPORT" tweeter, which, as far as I know, was not successful. I left the company shortly after that. Interesting comments about the stacked Advent Loudspeaker.

[@watdanuqta-mf5ms]

It's the mid seventies, In High School, and I'm in Pacific Stereo, in Oak Park, IL, with a few friends, and we're in their serious audio products room listening to Led Zep, "In The Light" to stacked Advents through Phase linear 4000 Auto Correlator and 700 amp at a level that I never experienced from an audio system. The music went from reasonable to explosive levels in an instant. It was revelatory, jaw-dropping! But then we listened to four stacked sets, two Phase Linear 700s, The playback source was a Teac Four-Channel open reel deck playing Santana Caravanserai from a true four channel tape. The sound of crickets with a wailing phase shifting horn, surrounding, no, enveloping us. I still remember this as one of those audio moments. We all purchased that Lp the next day and still have my original copy from that time and it still evokes that magic.

[@Parallax982]

When I was a kid, I was into music. My family had some unhealthy dynamics and my love of music was cut short by some traumatic events. I've spent lots of money on sound systems, trying to restoke the passion for music I once had, with limited success. But more recently, in the last year or so, I've begun playing with vintage gear. It reaches back to early memories from before the trauma and it's been allowing me to access that deep love of music again. At times, as if I were 15 and it seems neuroplasticity is a real thing, as I find my ability to appreciate music returning (regardless of the system on which I listen). I have several vintage receivers acquired this last year and three sets of OLAs. I've recently restored and stacked two of them, which I drive with a Marantz 2270. The result has been great. I've never been a heavy metal sort of guy. My tastes are mellow. The most extreme rock I got into was Pink Floyd. So this setup dovetails nicely with my tastes. I listen to classical, jazz, folk, folk-rock, singer-songwriter, alternative and the like. Mellow and melodious music. Can't speak to how this setup might sound with AC/DC, as I'd rather slit my wrists.

[@frankflores3948]

Kevin, I started my love affair with HiFi audio 53 years ago. And since I’m been a subscriber I have learned so much from you. I just wanted to say thank you and see you next Sunday 🙂

[@jeffbrooke4892]

Great topic. This is the kind of stuff that makes a guy wish he could drive down the street and hang out in your shop. Thanks!

[@bobsmoot8454]

I had stacked Advents, in utility finish, used a Crown D150 then a Harmon Kardon Citation 12 kit in 1972-1973’ish era while going to school in Nashville. Sold them to my good friend in NOVA around 1974. Also had stacked Quads in 1975 and that was quite the system for the time. Nice memories

[@johnvincent4048]

"Your speakers will steer your taste in music" My choice in music was mostly classic rock and heavy metal. I purchased my first pair of high quality horn loaded speakers in 2000 and since then my music listening has expanded to classical and jazz. And now I prefer to listen to those two genres.

[@steveperez210]

I've been running stacked Advents for years. It is definitely not high on wife approval, but my wife is tolerant as well, so all is good. I have run them with higher power (a Pioneer SX-1050 & a Sansui G-7700 and currently with a lower power Integrated Pioneer SA-6800. Have enjoyed them all. Thanks for the review.

[@martygillespie5486]

Nice to see that so many folks are still stacking Advents. I got my first pair in 1971 and thought that they blew away the competition at the time. After the Pearson recommendation, I bought a second pair. I was impressed … I thought the stacking opened up the midrange and lower treble, which I felt were the speakers weaker spots. I was running them with a Yamaha CR 2020 receiver, which I soon found out had very low power cap values (like 1000 micro farads … geesh). Whenever the volume went beyond medium, the lights on the receiver front panel would dim! It obviously didn’t like the lower impedance of the stack. I traded up to a heavily moded Hafler 500 amp. And what a difference. The speakers were much more open and at ease. The reason I tell this story is that you may not be experiencing all stacked Advents have to offer by driving them with a vintage receiver. Just a thought. Really enjoyed the comments section on this post. I didn’t realize that stacked Advents were (and still are) such a fixture in the audio community.

[@MashBill]

I worked at a hifi dealership in the '80s. We did this with Boston A200s. We also did it with Klipsch LaScalas! Talk about a wall of sound!

[@brunohebert1351]

You mean know I not only have to find 1 set of A200s but 2?? Man, you're killing me ;-) (but hell yeah would love to try that one day, in the meantime I'll stick with my one set of A150s)

[@MashBill]

@@brunohebert1351 A150s are great speakers too. You could probably stack those as well. :)

[@frankwilliams3615]

Stacked LaScalas?? OMG with the right amp that could be Orgasmick!!! scontent-den4-1.xx.fbcdn.net/v/t39.30808-6/380782159_2282513378624197_8901121640523502481_n.jpg?stp=cp6_dst-jpg&_nc_cat=107&ccb=1-7&_nc_sid=49d041&_nc_ohc=P9UqgVE8_dcAX8DzMW_&_nc_ht=scontent-den4-1.xx&oh=00_AfAGKdOWB817mvMxLJtlR0Gjz5cCIBvwgNA-50GH09flUg&oe=651330D3

[@72vespa]

Haven't experienced stacked Advents, but have experienced other stacked speakers. For home use I have a pair of B&W 602 sitting on top of my trusty Realistic Optimus 5b. When playing both sets together, the low end is much fuller, (no doubt due to the 5b's 12" woofer) when listening at lower volume (Apt.living). For professional use I have stacked BOSE 802 (Pro version of the 901) and then I can really pump-up the volume with a lot more bass & screaming highs to reach the back of the room (works well for outside gigs as well). But most important, it's just like you said, if it sounds good to your ears in your listening space, then Rock On .....

[@frh-freerangehuman]

This brought back memories. After my second divorce in 1998, all I was left with was my stereo equipment, my tools and my music collection. I had three sets of speakers that used to live in different rooms- an old set of Bose 501’s, a set or Audio Research w/12 inch woofers (I think) and another set small speakers that I can’t remember. I was in a little apt so I stacked all three and it was hilariously amazing. I ran my tv through them via a vcr and would watch football through this “wall of sound”. It felt like you were being hit when tackles were made. And music was awesome. While not nearly as cool as the stacked Advents, it was def fun. I should add that this all tan through a Nikko rack system that was what insurance deemed a good replacement for my that got lightning bolted. 😢 Thanks for bringing back that fond memory. Love this channel.

[@Kev2Bee]

I have two sets of Boston Acoustics A100s. They are about to get stacked! Power courageously supplied by: Mitsubishi DA-P20 preamp + DA15DC using A+B speaker outputs. I’ll run this setup for a few days and report back here.

[@Joe_Montfort]

Boston Acoustics made some great speakers. I miss them. 🥲

[@Kev2Bee]

Got it done. It actually sounds good, after a lots of shifting of 40lbs speakers up, down, left and right and rewiring the +\- cables. My big surprise is with my Mitsubishi DA-A15DC amp. and Mitsubishi C-20 preamp. ‘A’ speakers are correct left and right but ‘B’ speakers are L/R reversed. My best guess is that the terminals to the speaker outputs on the amp were re-assembled incorrectly. My amp was ‘serviced’ at some point, when powder coating of the chassis and rack handles was done. 😂 Skills, skills,skills. Overall, I like the sound but I did realize that each pair of A100s sound vastly different. My original 1978 SEAS set is much less sensitive and mellow than the newer B-A100 ‘tweeter’ set, as in nothing like the same. I guess a rebuild of the crossovers is due on the SEAS set. For now I have the bright set atop the mellow set, tweeter to tweeter. It is a massive weightlifting exercise with what seems like a very large number of variables at play. Still fun, every day.

[@eileenjaeger6222]

I did it in 1972 ,utility cabinets and a Marantz 2270 . Medium size room, sounded great. And not expensive. Many people were impressed.

[@k.givens788]

I took it up a notch. I put a pair of Isoacoustic isolation stand’s between the upper and lower speakers to isolate the cabinet resonance between them.

[@brochg]

Hey Kevin! I wanted to let you know that after a road trip yesterday, I made it home with a very nice pair of ADS L810’s, and hooked them right up to my Pioneer SX780. It was pure audio nirvana!!!

[@drteknical6571]

Lucky Boy! I'm running a set of 710s with Advents now. Can not beat the detail from the mid and tweeter dome drivers! Nothing like it!

[@brochg]

@@drteknical6571 I have been looking for over a year, and finally found a pair. My mind is blown!

[@DarinSkye-yo5yi]

Wow , I stacked my cerwin Vega 300 SE Select Edition speakers the same way these advent speakers are and WOW . The ceiling in my apartment is 14 feet high in open concept Artist loft . My whole cerwin Vega experience went to another level, I give them 4 cerwns the proper excersize they deserve. I have a new love for my 300 SE stacked this way . Thank you so much for this idea and my cerwin Vegas thank you as well . Ontario Canada.

[@michaelwright1602]

I love how you turned down the volume and changed up the music genre. I did the same when I purchased my Sansui 2000 to pair with some Zu Dirty Weekend speakers. I have since upgraded to a Sansui 4000 and a new pair of Zu DW6 Supremes. This vintage gear is something else and has totally changed my listening habits, and the enjoyment I get out of my system, as you mentioned at the end of the video. I do have two pair of Zu DWs in the house... No, we are not stacking those. Great video, keep them coming sir. ;-)

[@RoaroftheTiger]

Those Speakers (even a Single Pair) deserve a "big amp" - in Vintage Terms i.e. a Phase Linear 700. That's how Large Advents "can really sing" ! BTW - was lucky enough to meet Henry Kloss, on two different ocassions.

[@drteknical6571]

Ahhhh, Phase Linear! Another blast from the past!

[@johnreis8520]

I have A Pioneer Spec 1 going to an SX950 receiver -- out to 2 Emotiva mono blocks powering my stack. Sounds incredible. Have output 2 on My Spec1 feeding a small tube amp which feeds a pair of Baby Advants as well. A little tube boost if I want it.

[@MichelLinschoten]

Totally not needed 89db speaker and hardly anything special in terms of drivers. They were very basic speakers that could be driven with tons of gear to potential.

[@RoaroftheTiger]

@@MichelLinschoten You've obviously NEVER Heard them with a High Current Amplifier

[@FredPinkertonIII]

I was Audio Product Manager at Advent. I can confirm that lots of people used Advents with very large amplifiers and really liked the results. This wasn't an intent of Henry Kloss, but it was a byproduct of the design. The original Advent Loudspeaker was an acoustic suspension two-way (certainly not a "complicated" speaker), but I still don't think "basic" is a fair description. The 2 inch wide tweeter had a "very low for a two-way" resonance of 700 Hz (with a crossover frequency of 1200 Hz). I am not aware of any acoustic suspension two-way with a crossover that low (the Dynaco A25 was close). This improved the dispersion in the midrange compared to the standard 1800 to 2k two-way crossover. The in-box resonance of the woofer was 43 Hz with a Q of about 0.9, resulting in an easily-audible 32 Hz response on popular LPs of the time. At the time of its release, and for its enclosure volume, this made The Advent Loudspeaker the lowest responding two-way sealed box speaker available. The tweeter and the woofer were hand-made in Cambridge MA and were unique designs. Advent even mixed the paper for the cones. The downsides: While Advent called them "8 ohms", the impedance at approx 100 Hz was around 5.5 ohms. By itself, this was fine. Any amp could drive them. But it definitely created a problem if a pair was used in parallel ("Double Advents"). AND...The wider range of the tweeter meant that it had to handle more power than a higher crossover tweeter BUT the voice coil was only 3/4" in diameter. So you got tweeter failures when used with 30-50 watt amps if the owner persisted in trying to make the speakers play louder than the amplifier would support. The clipping distortion could burn out the tweeter. Oddly this seemed to happen most in college towns.... Thousands of people were perfectly happy with 20-30 watt amps, however. Because of its relatively low efficiency, The Advent Loudspeaker could actually show some benefit from large contemporary amplifiers. In the mid to late 70s, these were most often the Phase Linear 400/700 and the Dynaco A400. With these amplifiers, the woofer reached its limit first, with the voice coil bottoming against the magnet back plate. This clacking was SO obviously wrong that users turned the amp down and didn't attempt to push it harder. There were comparatively few woofer failures. @@MichelLinschoten

[@HarryButler-y8r]

Thanks for the run down "memory lane"! My first personal stereo system experience (not including my Dad's Magnavox console, in 1976 or so) was "stacked"... a guy who couldn't afford Advents had stacked pairs of Altec 891a boxes, and sold me the setup for $200, including a 90w/ch Sansui integrated amp. My experience was very similar to yours. I was steered to a Pioneer PL12 'table and was off to the races. Needless to say, my room (1/4 of a rental "house share) became the listening room, and the system served until the late '70s. By then I was employed at a small stereo shop and was offered a great deal on the demo pair of Acoustic Research Model 9 that was the "golden ears" offering, and I couldn't resist. They still sound pretty dang amazing in the livingroom, handling everything from the evening news to 60 years of vinyl (including Sheffield Lab and TelArc super premium). Yamaha receiver, Sony CD/DVD, JVC cassette, and, to "baby the vinyl", a Studer B790. It will do.

[@pauleichenberger4966]

Kevin, you made a great point. There is no such thing as a perfect system! My various setups with vintage Pioneer and h/k receivers and loudspeakers sound wonderful to me. Add in my vintage Thorens, Dual, and h/k tables and I am set for life! Love your videos and keep up the good work.

[@RonSiwicki]

I had a passion for all types of music since 1965 and I was a musician knowing professional musicians but I also worked as a hi fi tech consultant buying equipment at staff prices so I bought so much equipment to enjoy music on. I love soldering and working on equipment.

[@RickBranson]

Thanks Kevin for letting me listen to the stacked Advents I agree that they sound good but when I retuned home and listened to my pair of Advents in my listening room I am satisfied with the sounds they produce. I think that Wiim will be my next purchase at Skylabs.

[@billdepalma161]

Advent was the best ever best bass play Tubular Bells low organ bass tone Advent brings it out never knew it was there never stacked had the 1980 utility version my son has them now could never part with them. Reformed once. Great videos.

[@michaeledwards9376]

I may try this with my Polk Audio Monitor 5's, just for giggles, because audio is supposed to be fun, in experimentation and experience. Thanks for posting!

[@jimgoodfellow4127]

Had double Advents driven by a Phase Linear 700B in my dorm room in college in the early 70's. I had a very popular room. Friends loved to watch the oscilloscope on my Marantz 150 tuner. Worked in the local audio store. We sold a TON of Advents which helped a small audio store survive.

[@llucrescu9058]

I'm so glad to hear you talking more about the sound of an audio device than its specification. Good idea to try a modern digital source for a vintage audio system, but next time please use also an analog source, just for the fun of it. Thank you for your work and effort!

[@mr1enrollment]

Kieth: 1) how were these speakers wired up? Series or Parallel (likely would make a difference) 2) note that if they were placed side by side one could easily change the angle between the tweeters. Also both spkrs could be upright. I suspect that would allow some spacial tuning and/or reflectivity control. Interesting in any case.

[@alancalunas669]

Wondering the same thing about the wiring. Surprised it wasn't mentioned in the video.

[@kwinglee7343]

@@alancalunas669 Had double Advents. I tried both and preferred them in series for no particular reason. I did not notice a significant difference. You can hear them on my youtube channel where I had them hooked up in series. These have simple first order crossovers. I was concerned if wired in parallel, the impedance might drop too low for the amp/receiver.

[@jamesgriffith4]

Parallel which reduces the load to 4 ohms. I have mine driven by a Denon AVR-960H which you can adjust the speaker impedence to 4,8 or 16 ohms.

[@FredPinkertonIII]

Double Advents were always connected in parallel. Connecting them in series results in a "16 ohm" load on the amplifier. For a direct-coupled transistor amp (which is what most people had/have), this definitely halved the amplifier power, so the Double advents will not play as loud as a single pair of Advents. Advents in parallel were a slightly under 4 ohm load, which would "try" to pull twice as much power out of the amp. Not all amplifiers like this treatment, but most worked OK. Fred Pinkerton, at Advent from 1975 to 1981, was Audio Product Manager.

[@fonkenful]

Some of us boomers have war stories about this combo, and without reading the entire comment thread, I’d opine that y’all should revisit his with more power if you want to really open them up - 200wpc would be nice. The best I can remember hearing them was Marantz 500 power amp; this was well before the advent (sorry, couldn’t help myself) of digital, and the premiere turntable we had available in the showroom was Thorens TD125/SME 3009, any too many phono carts to try to remember exactly - we are talking over 45yrs ago, folks.

[@AirDOGGe]

I discovered something like this on a trip to Stereo West to check out some speakers on sale back around 1980. I auditioned them in a soundproof listening room and was very impressed with the full, rich audio. Then the salesman noticed someone had activated 3 different pairs of speakers on the switch panel. He corrected it so that just the on-sale speakers were the only ones playing, and the sound fell flat. Needless to say no sale was made that day. But something was learned. Some years later I tried a setup with a pair of 60watt JVC amps, one driving Cerwin Vega HED 1230 speakers and the other powering a modified pair of Bose 501s that had the bouncy tweeter array removed and forward firing mid/high drivers installed. One amp controlled the second through the preamp-out/in jacks. The sound was so awesome. Set-up was critical but results were worth it.

[@marianoritacca4971]

I have 2 pairs of Yamaha NS-1000M stacked un a cuasi D'Appolito system layout and they really sound amazing. Not that they sound other way by single pairs. I love their sound anyway. Drive them thru a Sansui AU-d11

[@haqitman]

Once a friend brought over a pair of Advents. They needed some work, the surrounds were barely there and i'm sure they needed a racap. But man, they sounded really great! Tons of detail and presence. Was not expecting that from a set of old, well used and relatively cheap speakers. Something of a hidden gem in my opinion. Never heard them stacked but would like to some day.

[@dstarling61]

Maybe not a hidden gem, but a forgotten one.

[@generatorjohn4537]

Kevin, Discovered your channel recently. Nice channel. Made me appreciate my stereo system even though it doesn't get as much use nowadays. I bought my system in 1979 at Tech HiFi, Warwick, Rhode Island across the street from the airport. Anyway my system consists of a Philips 7851 receiver, Sanyo TP 636 turntable, Audio Technica AT90E cartridge, pair of Infinity Qa speakers. At the time I paid $620 for the bundled system. Tech HiFi would bundle systems together and typically supply a receiver, turntable and pair of speakers. In my college years (1974-1978) they would drop off their catalogs onto the college campuses in Southern New England. Thanks for keeping 70's vintage stereo equipment alive.

[@TheFibtastic]

I did it with two pairs of the similar KLH-6s, resulting in severe comb filtering. Sounded bigger if your didn’t mind that certain frequencies were completely absent .

[@BillyDenton-nx3oy]

Love to hear a Dahlquist mention. I stumbled into a pair of DQ-8s about 2 years ago. At $150/pr., I had to take them home and give em a shot. The sound was awe-inspiring. They've been my main speakers since. They're not visually commanding, but looking bad apple isn't their job. Their job is to deliver sound, and man do they ever do that well !!

[@johnnytoobad7785]

My best friend's in High School ended up with a "Double-Advent" that they took to college. I got to hear it in their bedroom at home. Because they are wired in parallel they didn't quite have enough power to drive them adequately. They sounded great though... They eventually blew a power-trans in their amp while in college. Most of what they listened to was classic jazz and new jazz-fusion. As for me..I stuck with my KLH'5's and a Dynaco120 Power Amp that made it through college...🤓. Unfortunately, I ended up selling both the speakers and the amp.

[@markburnham7512]

I had Advents for many years. First purchased in the early 70s, they were my only speakers for years. The first thing to go was the fabric surrounds on the woofers. I replaced the woofers with Cerwin-Vega. This carried me for more years until the foam surrounds dried up and turned to dust. At that point I replaced the whole thing with Klipsch.

[@jamesallan729]

I ran double Advents in college, driven by a GAS Ampzilla that I built from kit. 350 watts per channel at 4ohms. Sounded great. Blew out a few of my woofers playing drum solos, etc. I still have the bulletin shown in the video.

[@scottlowell493]

I remember the dorms in the 80's. Guys did this. Not just with advent, but with dissimilar speakers. "Well the top speaker has better HIGHS and the bottoms speaker has better bass". It was also the "wall of sound". effect.

[@ivansbacon]

My girlfriend is stacked and she has a mind of her own. She does not steer my taste in music and i do have to attenuate her at times, but she likes.

[@dandinhofer9240]

👍

[@ronm2970]

Purchased a set of stacked Advents years ago from Craigslist for my garage sound system. Added a Polk 10” subwoofer for a fuller sound. Love my Advents!

[@Haakonisak]

I've had a pair of Advent 3 bookshelf speakers for a while and found me another pair a couple of weeks ago. It opened up a whole new world, I really enjoy listening to them, they fit the Pioneer SX-550 like hand in gloves. Tried I them on an ITT 8033, same experience, I really enjoy the difference in dynamics on low volume.

[@CaptainRon1913]

Back when I was in college in the mid to late 70's, walked into this busy bar which was playing rock n roll music of the time. The bar was packed but the music came through crystal clear and sounded awesome. Snooped around to find out what system the bar had. 4 Advent speakers, McIntosh amp/receiver, and a Sony reel to reel.

[@roberthaysley4245]

Stacked Advents and the Pioneer 9100 was my first good system in the early’70s

[@BootJamesOut]

Hello folks wow you just brought me back 50 years back when I was 14 16 years old and guess what I did the same thing with Hitachi speakers when the parents weren't around. Get more snap bass and also the woofer was hired in the middle of the room floor to ceiling how did nice effects and now we see high-end speakers using the same configuration, Yes Kevin's right do not let anybody tell you how to listen to your music. I can't play an instrument by play around with how the sound sounds Ride Easy

[@bunkie2100]

Rrgarding mid-late ‘70s mainstream Japanese amplification, the manufacturers placed enormous emphasis on nailing the power ratings at 8 ohms while adhering to a specified price point. This meant that they didn’t produce much more power at 4 ohms. I seriously suggest going much larger and trying the “impactful” music again. There is a reason why Phase Linear kicked off the monster amp thing, speakers like the Advent and the classic ARs loved power and lots of it. To back up my statement about the oower limitations, I share this experience. I was an engineering tech at H.H. Scott at the time. This was after the original company had been sold. We sourced our product line from various Asian suppliers. The Scott entry into the receiver wars was the 390R which rated an honest 120 watts RMS per channel. It was designed and built by Kyocera of Japan. We took the amplifier circuit (hand crafting new circuit boards) and built some prototype power amplifiers. One was designed to be 120wpc and the other 200 wpc. The 120wpc version used the same output transformers and transistors but had a much better power supply using a toroidal transformer and some seriously large filter capacitors. I remember that it produced about 150-180 watts into 4 ohms (as measured on out ST-1700 distortion analyzer. For the bigger version, we used stacked output transistors (to handle more current) and an even bigger power supply with higher DC voltages. We got about 250 watts per side out of this beast at 8 ohms but were unable to measure at 4 ohms because it was just too big for what we had available as a 4 ohm load. Listening to these amps back then with the typical New England acoustic suspension speakers was a revelation. You could really drive them hard and they sounded great playing dynamic music.

[@clemmtec9506]

Thank you for sharing this, Yes I smoked my sansui amp like that , I took it to a repair guy and never saw that amp again.

[@birolerkan65]

It was a new experience for me. Thank you Kevin for this good information ... 👍

[@fraserhenderson7839]

I drove my Advents with Advent model 300 receiver pre amping BGW 750 power amp, served by Marantz direct drive turntable with Mayware Formula Four tonearm and AKG P8E cartridge. Only one set but I could make my windows move... I added Ohm C2s on a Phase linear 400 and I was invited to live elsewhere almost immediately.

[@dandinhofer9240]

Hi Kevin. Long time fan. This stacking review episode was so very long waited for, and hopefully-thankfully expected. I mostly listen to my music 🎵🎵🎵 at lower volumes, but then on some days I wake up somewhat frisky and need a heavy dosage of "let's blow the roof off". Hence, there's nothing more underwhelming than knowing one's own speakers cannot handle 100-130 db without blowing the precious drivers. Therefore, for the last 5 years I've been revamping my entire collection with a stacked speaker setup starting with Kappa Infinity, Honeycomb Technics, NS1000M Yamaha, ADS L710 and finally Monitor audio Silver100 G6, with absolutely glorious results. What a revelation!!! Unfortunately in the past I listened to some opinionated individuals who condemned the stacking practice but truly haven't a clue. I've found there are two rules i find helps immeasurably with strident high-mid harmonics. 1. Stack'em always with the Diappolito configuration. 2. Use rubber puck isolators between cabinets 3. Adjust/turn the attenuators down (lower) - or if not available equalization helps. Thanks

[@t-mar9275]

A friend had a pair of Sansui SP-X11000, which was a factory built, stacked loudpseaker system. Each loudspeaker consisted of two separate cabinets that sat on top of each other and had an electrical interconnect built into the top of the lower cabinet and the bottom of the top cabinet. These were large, very heavy speakers, with the system having a total of four, 17" woofers. The popular speakers to stack in my region were the Bose 901. Offhand, I don't recall any friends with stacked Advents. The only Advent product that I ever owned was their seminal model 201 cassette deck.

[@victorjohnson7512]

This is why so many open baffle designs use a big 15 inch woofers on top and bottom, with a full range in the center.

[@altokheim]

Great piece of speaker nostalgia video. I remember the stacked Advent era well (and waiting by the mailbox for the next edition of The Absolute Sound). Davenport, Iowa had a local Advent retailer who promoted the stacked concept heavily. However, as you say, there were other good options, and I sold many pairs of ADS L810s, ESS AMT-1As and even Magnaplanar MG2s as alternatives

[@Mark-rw3kw]

I heard the stacked Advents at a friend's home (and also at an audio shop) in the early 1970's and they sounded a little better than just a pair of them. But I bought the ADS L810 in 1982, and those speakers (not stacked) blew away the Advents by a wide margin.

[@dnate697]

This also works with speaker works with XP 9c Fisher Ventage. They are meant to be placed Horizontally and Not Vertical. So not only upside down but horizontally should be tested for tall speakers or speakers already on a stand. They might need a slight inward cant/tow.

[@drteknical6571]

Double (stacked) Advents were a real thing back in the mid-late 70s. A friend who worked as a very successful salesman at Raleigh NC's most successful stereo store had a set. He tried the two popular stacking options. I don't recall which way he preferred. He drove them with a McIntosh solid state Tuner/Pre-Amp and a McIntosh 205 watt per channel power amp. Source was usually a most excellent turntable with a top of the line Ortofon cartridge. He also owned a very nice over-stuffed couch into which we were propelled by the massive SPL so generated! He later sold the Advents and switched to Braun/ADS 910s. Equally overwhelming and huge! Ah youth! I'm currently running a set of Braun L710s stacked on top of Advents. Very nice sound!

[@tomlindalewis2146]

When I had a set of original and a set of new large advents I had tried them stacked!😟 Thank you for another informative and enjoyable episode!

[@cherylridone2155]

Our current set-up consists of a pair of stacked ADVENT(large) speakers...on pair I've owned since new in the '70's, the other paie were my mom's, also from the '70's...my pair has the walnut veneer(refinished), mom's pair are the ulility cabinet...all have had the LF driver surround replaced...these seem to play effortlessly, with a balanced if slightly directional sound...quite pleasurable...the "other speakers in the room" are ESS Bookshelf units purchased as dealer demos in the early 80's (also with rebuilt LF driver surrounds)...(David)...

[@jamessemelka9590]

My exact stereo setup - 1975 SIU, Carbondale. Stacked Advents, Pioneer separates, and Technics turntable. Takes me back... and I'll be returning!

[@tomhill9445]

Right now I'm running JBL P30s with Polk Monitor 5s on top. Between the pair, its all covered. The Polks are crispy and the JBLs have a strong bottom. I've never had old Advents but Ive had several newer ones. Legacy 2s, Lauriettes, Herratige and Prodegy 2s. I refoamed all of those. I still have the Legacys and the Prodegys. I like em all.

[@ron521]

I have two pairs of stacked speakers in my living room. I have two pairs of kirksaeter speakers which like the advents use a sealed enclosure. I power them with two PS Audio Sprout 100s. Back then speakers used paper cones and were more sensitive than more recent speakers which are usually ported. I prefer sealed enclosure speakers because to prevent possible rodent and or insect damage.

[@davesublette7447]

Having made the comments below got me to remembering when I bought the Advents and hooked them up the first time. I was listening to one of my favorite albums (on vinyl). It was Offenbach, Gaite Parisienne. As I was listening, I sensed, rather than heard someone knocking on the front door. You know how knocking vibrates the door frame and that low frequency goes throughout the house. You feel it, not hear it. So I went to the door. There was no one there. So, I went back to listen. A few bars later, someone knocked on the door. Again, there was nobody there. It happened again a few bars later and I finally figured it out. There was a LARGE bass drum in that orchestra. Someone was stroking it lightly, not hitting it. I was feeling the vibration. I had listened to that recording for years and not heard that drum before. The cost of the double Advents was instasntly justified in my mind!!

[@Projacked1]

If you can't play all genres , you have to change the placement, slightly. The response has changed with stacking. Probably the bass region, so give it more width, just an inch to start with. I have noticed this as well, just by testing placement of a single pair. Metal music is a good example, if that sucks, fix it with placement as much as you can. I softly 'hammer' with a closed fist on the cabinet to move it very slightly. So you don't mess up an already good sounding image. Also some tape to mark the original position where everything sounds good, so you can always go back. Placement is probably the most underrated part of speakers, and it's the most important! That's where magic happens. EVERY speaker pair has it's own right placement. There is no set distance or angle/ toe-in. The triangle setup is usually BS, unless you have a even geometric room with enough space, with nothing else in it. Some speakers hardly need toe-in, because of it's design. Also, people often have the speaker too close to the wall. Usually a case of limitation in the room.

[@pmpzen]

I just recently bought a pair of DCM TF500’s of which I felt the soundstage of the 6” driver and the Vifa tweeted sounds amazing but lacked low end. Tried connecting them in parallel with my Advent Maestros, which sound good on their own, but sounded bad combined with The DCMs. Decided to stack the DCMs on top of B&W 602 bookshelf speakers and it just punches the whole spectrum. Previously when I asked around some forums about mixing stacked speakers I was told by someone in the advent crew that they needed to be the same model speakers to work. After my experience I found this not to be totally true so my recommendation is to experiment whatever you’d like and always keep in mind what your amplifier or receiver can handle. Have fun with it and maybe you’ll discover something new.

[@tomtripi7497]

Worked at a stereo store in the late 70s. We used too set up 2 pairs of large Advents, 2 per side corner to corner at about a 35° angle...in a V shape. Thought they sounded great that way.

[@barneyrubble4827]

I did this in college, 1977. They sounded great but had to play with the speaker wiring, had to hook them up in series to protect the amp overheating

[@mattlehnardt783]

soo cool to hear about this blast from the past, and that it still rocks!!

[@RonSiwicki]

Working for an Advent speaker dealer I had a double Advent system. I went through many types many types of equipment at staff price.

[@paulhare662]

Never did the stacked thing but currently have a pair of Infinity SM150s and a pair of Polk 10s all hooked up together powered by a Phase Linear 400. Low volume sounds great. High volume sounds great a half a mile away.

[@saladsalad9991]

awhile back i saw a craigslist ad for four bose 601 series two. refoamed all the woofers, and experimented with stacking them...yes, the plastic frame that covers the port hole and tweeters (what bose calls a tweeter) was able to support the stacked speakers...and it didn't sound bad, but i ended up selling each pair for 8x what I originally paid to a man from Vietnam that lives in Virginia.

[@riclambert4291]

Hey Kevin, Have enjoyed your videos for a while and have been a subscriber, first comment though. I must confess, I am a long time Advent guy, sense the late 70s in fact. I've had/have many other speakers but the LG Advents have remained my standard. I know they are not the best sounding speakers, but within my budget I feel they are very good performers. It has been just in the last 10yrs that I have been aware of the stacking LG Advents in he manner you described here and I do think it improves the performance significantly. One thing I didn't catch in the video was the wiring method that goes along with this application. That connecting each stack in parallel is part of it which brings each stack down to around 4 ohms. Maybe I missed it, but I was listening for it. It is important also that the amp powering them can handle 4 ohms. That said I have found that 30 watts RMS is plenty to run them up to impressive DBs. At this time I am running them through a Sansui 5000x which puts out 85 watts @ 4 ohms. I seldom have the volume above 2.The sound pressure builds up pretty quickly after that. Interestingly you mentioned turning them down some from where you set them starting off. I have noticed I am doing that as well as I have cleaned up my system with cables, connections and components. My next step in this process is to have my LG Advents recapped. I have a set of Heresy's 1s that have been recapped and been enjoying them for completely different reasons. P.S. I don't think it's a Myth. R

[@daviddrake6875]

What cables?

[@j.patrickmoore9137]

Given an amp that can deliver the current, doubling up (such as going from A to A+B setting) doubles your power output but only increases the sound level by 3 dB. So... if you drop your volume by 3 dB when you put the second set into play, you will essentially keep the same level of loudness but drop the total power output back to where it was with only one pair playing.

[@007fredh]

I may be wrong, but I don’t believe Kevin was running them in parallel that would mean connecting speaker to speaker. I believe he was just having speakers set up on the A side and the B side and playing them together.

[@johnnyhiett]

Great stuff!👍 I ran stacked Dynaco A25's for decades. Dynaco had a worksheet that showed how to connect up to 4 pairs but it was flawed. I used multiple Dynaco 400 watt amps to solve that. Comb filtering is always an issue based on the listening distance. I preferred side ways stacks when I used 4 pairs. A album that really works is Grateful Dead Euro 72 live. It recorded their Wall of Sound tour. Only way that album sounds good. On your Arvents try the acoustic Taj Mahal "Ooh So Good in Blues" which has the Pointer Sisters on 2 tracks.

[@glenncurry3041]

I bet it was Fat Julian's in Atlanta! I remember when the stacked Advents hit. What a marketing dream! They did not have to come up with an upper model, just buy two pair! And yes the sound was very impressive for the time. Interestingly we see the design becoming popular in expensive systems. Where they vertically stack drivers with the smaller in the center. As the AR rep at the time. With AR introducing their new Series 9 line at the time. I would stack two pair of AR90's to show we could do it as well. But that for less money you could move up our line instead.

[@dandinhofer9240]

Two AR90's stacked!! That must've been a 7 foot sight to behold 😮...

[@glenncurry3041]

@@dandinhofer9240 My bad, AR91's. Been a long time and not AR9's!

[@Poppinwheeeeellllllieeeeez]

Just bought a pair for 50.00 2.5 hours later new foams and caps installed....grills washed with tide and vet vac'd dry and finished in the sun. Wax and feed on the cabinets...like new advents for $100. VAN Morrison Astral weeks or Moondance or Tupelo Honey would sound fantastic. Parallel wiring will draw down into low ohms and will smoke your amp. Series will up the ohms and reduce current output or current draw from the amp. Are your sure about parallel?

[@dstarling61]

As long as your amp can handle a 4 ohm load. If it can, it will almost double the power output to speakers. Be careful, a lot consumer grade equipment won’t go below 8. I have a pro Crown amp that can go as low as 2 ohms.

[@gtrguyinaz]

Had them for 7 years in the 1970s…. Moved on to AR9LS…. Now I have dynaudio C5s….

[@LakeNipissing]

Regarding the stacked speakers with the top speakers being inverted... I did exactly this with a matched set of four Realistic Mach One speakers I inherited from a rollerskating rink that shut down. This puts the horn tweeters at about the 3 foot level and they actually look really good like this, with or without the grilles, since the horn tweeters aren't covered. They are connected to a Hitachi SR-2004. Using the speaker selector buttons, the effects of having just the bottom speakers, just the top speakers, or both can be compared. I would say there is a definite reduction in bass 'boominess' using the upper speakers instead of the bottom speakers, when in pairs, but I like the sound best with all four of them operating. And Wow, PS Audio... I used to watch their videos back to back, when they would be recommended by KZbin. I haven't had a recommendation from KZbin for PS Audio for so long now, I almost forgot about them.... strange how Google's algorithm works.

[@rodsilhanek]

I have stacked AR LST 2 and that sounds amazing from classical to Master of Puppets. Another good video, thank you and keep it up.

[@CTinNorthville]

Lucky you. I have AR4x on AR3a.

[@carlosoliveira-rc2xt]

Stacked horizontally 8 AEI 2-way speakers with 2 amps back in 1979. Added another 4 speakers and an amp the following year.

[@onemat2000]

Hi Kevin, I wouldn't stake my life on it, but I think the walnut cabinets predated the vinyl veneer. In the seventies we sold 50 pair every couple of months. We had a lot of space in the backroom just for stacking the Advents.

[@martinhiggs7027]

I worked for an extremely HI-END retailer in the 70's. ! I had a pair of ADVENT's (out of phaze) to push a sale of our products ! in my humble opinion the Advent 4-B was the reference standard product until the early 90's !

[@dboy6896]

I remember the stacked advents being awesome in a hi-fi listening room in the 70s. I have a JBL stack in my den currently with L100s on the bottom and 4311s on top. This puts the tweeters together because the way the speakers are laid out differently. I am just running them as speakers A and B. Has anyone tried this? I really like it. Keep on rockin!

[@johnreis8520]

the bridge in Led Zeppelin's Whole Lotta Love will travel around the room with my current stacked advent setup. Im in a railroad, Broklyn apartment and the low volume wall of sound works for me. Alice Cooper's Easy Action really sings ...My stack is 2 weeks old!

[@johnreis8520]

I have A Pioneer Spec 1 going to a Pioneer SX950 receiver -- out to 2 Emotiva mono blocks powering my stack. Old and new. Sounds incredible. Then I Have output 2 on My Spec1 feeding a small tube amp which feeds a pair of Baby Advents as well. A little tube boost if I want it. Its still a new set up, still playing with it. So far I could not be happier.

[@andysmith-ne1qs]

Best all time stacked ..Yamaha NS 1000 M with those ultra revealing 3 “ berylium mids and 1 “ tweerers

[@dandinhofer9240]

Ya mon!!!!

[@smterrillion]

Great video. Just want to say how much I am enjoying your videos. On your recommendation, I recently picked up a vintage H/K 330c. The styling and innards are elegantly spartan and it sounds fantastic! I have it driving Sony SSCS5s and a Klipsch subwoofer (yes - using the adapter and connection method in your “how to connect any sub” video). Also agree the 330c is not necessarily warm so much as it is lush - the SSCS5s can be a little harsh on the highs, especially at higher volumes, and the 330c smooths it out nicely. It was supposed to be a secondary set up for the basement but, honestly, I can’t stop listening down here. Listening to Willie Nelson Bluegrass streamed from a Wiim mini (early adopter on the Wiims - I have them all over) into a Schiit Modi DAC into the 330c as we speak … home run.

[@unclefuncker3098]

Love Over Gold is the record I use when setting up a new cartridge. Great sounding album.

[@Kev2Bee]

Got it done. It actually sounds good, after a lots of shifting of 40lbs speakers up, down, left and right and rewiring the +\- cables. My big surprise is with my Mitsubishi DA-A15DC amp. and Mitsubishi C-20 preamp. ‘A’ speakers are correct left and right but ‘B’ speakers are L/R reversed. My best guess is that the terminals to the speaker outputs on the amp were re-assembled incorrectly. My amp was ‘serviced’ at some point, when powder coating of the chassis and rack handles was done. 😂 Skills, skills,skills. Overall, I like the sound but I did realize that each pair of A100s sound vastly different. My original 1978 SEAS set is much less sensitive and mellow than the newer B-A100 ‘tweeter’ set, as in nothing like the same. I guess a rebuild of the crossovers is due on the SEAS set. For now I have the bright set atop the mellow set, tweeter to tweeter. It is a massive weightlifting exercise with what seems like a very large number of variables at play. Still fun, every day.

[@THELIBERAL]

Very popular set up in seventies especially with some of the big amps of the day, Dyna 400, Phase 400, Marantz 250. Amp that had good power supplies and could handle low impedance . AR 2x also worked. Big sound. We also used them with quad receivers running one set of stereo channels to each pair.

[@j.patrickmoore9137]

amps that could handle low impedance - I visited the Phase Linear factory when the bias transistors blew on my Phase Linear 700, took it up for warranty work myself. While there, I got a factory tour. They had a Phase Linear 400 that was driving multiple sets of speakers in the big factory room - it filled the room, the VU meters were dancing and I could only imagine that the total impedance was down around 1 ohm or less. I ran my Advents with a fast AGC 3 fuse, which is probably what saved them when the bias transistors blew (to be fair, it had been a floor demo unit in a walnut cabinet, but I ran it w/o the cabinet - my guess is that those poor transistors were probably just about worn out before I got it).

[@kroywen2847]

I've 2 pairs of OLA, both in bullnose version. I love them, but never thought of stacking them. Impatiently waiting to try that

[@markbarber7480]

I ran stacked advents, mac 2105 back right when they first came out, absolutely an awesome setup

[@Jambi14]

We were doing this in college in the early '70s. Sounded great, but given the flow of inebriants through the house at the time, I cannot say how objective we wer (had a Hafler pre-amp and Phase Linear 400 amp).

[@josephsaucedo8691]

I have done the same thing with my tower speaker set for years and didn't know that it was a thing at all never payed attention to it till now. Mine are also off the ground as well a set in each corner angled never try to flip them. I definitely love to push it to the limits 🎵🎶💯👍✌️🤔

[@georgekriese4687]

Have a set of Advent's from 1970 with the nice wood cases & re-foamed woofers. Also a set of JBL 325a's from 1985. Neither sound great on their own but much better when both are running off the same receiver.

[@leonardkrasner5811]

Did this with Altec Model 3’s. Fantastic!!!

[@Foxrock321]

I have 4 79’ vintage Large Advents, bullnose walnut speakers and the Double ring fried egg tweeter pushes the midrange down into the 1000 hz range.it’s what makes the sound so smooth..AND, I have mine stacked on two Toby subs. …now they are monsters..the subs are self powered and ported …felt not heard..

[@atw4321]

Im a polk audio fan all my speakers are polk 4 S55s with 100 watt 10 " sub and bi amped 200 wpc ROCKS THIS HOUSE

[@Exgol2005]

Success with stacking has got a lot to do with matching a capable amplifier (lower impedance when wired as parallel).

[@katebloggs8243]

Kevin, if you haven’t watched/listened/read any interviews with Floyd Toole, run, don’t walk! I think you would find what he share very interesting, and confirming and expanding of what you have come up with. Floyd is retired, but he did psychoacoustic research for the Canadian government for decades - zero conflict of interest. He later worked for HARMAN continuing his research, but he is such a smart scientist that there is no question of bias. Sean Olive overlapped with Toole and is carrying on the work. I have only read excerpts of Toole’s book but what I have read is so incredibly interesting and clear and mind-blowing. Anyhow, your experience with the stacked Advents totally jibes with what research has found, and the explanations behind Why is a page-turner. Thank you for how you approach audio - I think it is potentially a great influence on the hysterics and ugliness infecting online audio discussions. We need Gen Y and Z to get on a good page so the audio world can blossom into its true potential as older listeners driving the discord die off. Sad to say it like that but it is what it is and for the sake of truth and beauty of music we shouldn’t avoid it. Audio culture became something like a cancer, but music, openness, kindness & sharing, and the heart of it all will naturally steer us back, but we can get there quicker and more lastingly if us in-betweeners do right by the present and connect the best of the past with the open future.

[@spacemissing]

In 1980 I was working at a store where, on a suggestion by a customer, we tried stacking Wharfedale 30s on top of Wharfedale 50s. It sounded really good. I believe many pairs of speakers that are identical or at least sonically similar can be stacked to achieve an acoustical benefit.