How to Modify Klipsch speaker horns for better sound.

How to dampen Klipsch Cornwall IV horns for better sound. I apply Dynamat Extreme to control horn ringing and describe the sonic changes that result.
CAUTION! Proceed at your own risk. I am not responsible if you damage your gear, hurt yourself or you don't like the results you get.
Here are several precautions:
1) Disconnect and unplug your power amplifier from your speakers before attempting anything
2) Dynamat Extreme sticks very well. Consider this modification irreversible. Only attempt it if you are confident that you know what you are doing. I'm not responsible if you don't like the result.
3) Make sure not to apply Dynamat where it will interfere with a horn's proper fit into the speaker cabinet.
4) Mark the wires and the drivers so you can be sure to properly reconnect the wires when you reinstall the drivers. If you don't do it correctly, you may blow a driver, or your amplifier or have some drivers out of phase with others.
For those that may ask, here is the Dynamat I used: www.amazon.com...
It's an 18x32" sheet, which was enough for the midrange and tweeter, for my pair of Cornwall IV speakers. Some material was damaged from the shipping folds, but I still had a little extra left over.
Good luck and happy listening!

[@analogaudiorules1724]

I'd like to see what their designer, Roy Delgado has to say about this and these changes.

[@thebostonaudiophile]

Me too.

[@rongoodman8874]

Needed a Covid project and although skeptical, I decided to go ahead on my newly rebuilt and upgraded Klipsch Belles. Well all can say is" thank you". The improvement is absolutely worth 90 minutes of work. What I noticed is a smoother mid and reduced distortion. This improvement manifests itself in easier listening even at higher concert volume levels. This should be a standard upgrade on all horns.

[@thebostonaudiophile]

Fantastic! We are hearing similar things, I beleive.

[@daveyurkovich9459]

What upgrades dis you perform on your belles?

[@raphaelness1239]

What model Klipsch speakers did you modify?

[@debragibson3489]

Husband here....your description of finding new problems IS Spot on! This will be a fun project and improving on my audio journey......I am also recapping my Heresy's and JBL's.......fun, fun, fun! Thanx!

[@thebostonaudiophile]

Thanks!

[@davidt8438]

I’ve been wanting someone to do this exact thing for over 10 years. Thank you for being that someone. I think I would have done a little less in certain areas but , yea why not try it everywhere and see how it sounds. If it’s too dead you can always peel some away. Great job.

[@fredbloggs6080]

He says in the description that the stuff is so sticky you should consider it irreversible.

[@justinspires9151]

Soo many comments from people who clearly don't understand that input/output coloration is NEVER a good thing. Any coloration of the original audio should be done by the producer prior to final release. Also, just because the company sold it a certain way, doesn't mean the engineers were happy with it... only that it allowed the company to hit a predetermined price point in the market. Keep doing what you enjoy, the trolls will do the same I assure you.

[@thebostonaudiophile]

THANK YOU!!!

[@johnhodgson5313]

Very well done. You have a great understanding of the subject. Our brains do a lot of "error correction" when we hear things, and the more error correction we do the quicker we tire. I learned this some time ago when setting up sound for large instructional conferences in stadiums. Maybe the instructor isn't the reason everyone is sleepy. Is there a lot of echo, or are there resonances or peaks that can be tamed, is there a lot of mid bass from proximity effect? The idea is to get the desired signal over arena noise as high as possible. So by damping the horns you have raised the ratio of music to the plastic noise from the horn. Bracing the cabinet should produce the same effect. Now that your brain is doing less work it will concentrate on the bass and/or the next problem. I also like how you illustrated the sound masking effect.That is why we put loud stereos in cheap cars so we can't hear what is wrong with them :-)

[@thebostonaudiophile]

Yes, exactly.

[@wa4aos]

In 1985 I realized my metal La Scala metal horns were in need of serious dampening. A friend mentioned a product he used called Devcon which is an epoxy for repairing conveyor belts. I bought some and mixed it up; just enough to do one mid-range horn and tweeter at a time, then mixed another batch for the second pair. . I took the drivers off of the horns and sat the horns on wax paper with a little oil rubbed over the surface as a mold release. The Devcon was thick enough to not run too fast. I did both mid-range horns and the tweeters and they turned out EXCELLENT. Now my Klipsch La Scala's sound great. Later I bought Crites crossovers and that helped as well. As the Devcon dried and hardened the finish was shinny black much like the volcanic rock called Obsidian. I will uses these until the end and never need any other speakers.

[@echo2gordon]

Horn drivers can have a nasal,"honking" quality. So, I decided to try this with my Forte IV's. After making stencils, I applied the Dynamat Extreme to one speaker as described. Then, setting the audio to "mono", I did left-right comparisons while listening to symphonic, jazz, vocal, and percussion tracks. The Dynanat application significantly changed the sound quality. The locus of sound moved out in front of the treated speaker, while the sound on the untreated side was more within the speaker cabinet. The treated speaker did sound somewhat smoother, sweeter, and more direct. The untreated speaker was louder and seemed to have more resonance - like it was in a larger hall. High frequencies were significantly attenuated on the treated side effecting ride cymbals, high woodwinds, and trumpets. I found the highs flat on the treated side and so I removed the Dynamat from the tweeter. With just the midrange horn damped, I continued the side-by-side comparison. Vocals were smoother on the treated side, but I found myself preferring vocals with the more open, overtone rich sound of the untreated Forte. So, after much reflection I removed the dampening material. For me, the application of Dynamat produced an over-dampened character. All in all, I learned a lot from this experience. I think that resonant vibration of the walls of the horn drivers significantly contribute to the open quality that I like in my Forte IV's.

[@thebostonaudiophile]

Well, there’s no substitute for your own experiences and preferences. For me, the Dynamat increased the naturalness, nuance, ease and dynamics considerably. Also, I too listened to one speaker before I did the second one. The difference was much more dramatic when I listened to the modified pair than when I just compared one stock speaker to one modified speaker.

[@slawomirp]

Upgrading is not na easy stuff. I have replaced cheap capacitors once with expensive audio grade ones and the sound became so sweet… I could not listen to it anymore. Terrible. I have installed old capacitors back restoring original bit sharp character of the loudspeaker I liked.

[@davevolz6138]

Horns nasal Horn bass, tunnel Thats just the nature of the beast

[@icanseeall-inthisreality]

i watched videos about doing this a while ago and i decided back then that if i was to do this i wouldn't be using dynamat, if i was to do this i would just put some gorilla tape on them or even normal sticky tape. because it's not how this guy's says it it's not about the plastic moving it's all about dampening not how the plastic moves. so, there's no need to go to the extent of using something like Dynamat which will just about completely dampen it, all you would need is something that will dampen it a small amount such as simply putting on some normal thin see through sticky tape or if you want something more some gorilla tape.

[@davevolz6138]

@@icanseeall-inthisreality Mortite is actually the best. It’s that gray silly putty also know as duct seal.

[@MikeGervasi]

I did this with 4 strips on each horn. What I hear is a reduction in overtones which seems to take some of the muddiness out of them. Definitely helps the clarity.

[@thebostonaudiophile]

Glad you like it! Yes, I should have mentioned that one can get big benefits from a few strips of treatment. Obviously, I covered the entire horn, but if that’s too much hassle, there’s benefit from partial coverage. Without doing a careful comparison, I can’t say if what I did was a waste of time or if your approach “left something on the table”.

[@shipsahoy1793]

Yes everything you said makes sense.. I noticed in your last video on these speakers you had cited some issues you noticed, such as box resonance and resonance in the horn, but as you found out,, when you make changes, you’ve altered the original personality of the component. This is why when people talk about modifying and customizing stuff, I always tell them to make sure you know exactly what your expectations are, and what affects what, so you know what you’re giving up, what you’re getting, and whether that’s overall what you want to be getting. The resonances you removed were obscuring the sound, and by removing them you created a sonic opening that brought other sonic deficiencies into the foreground. When I’m trying to listen critically to audio, I need the absolute lowest ambient noise to do it. This includes the noise floor of the equipment driving the speakers, mechanical or electrical !! You probably work the same way to realize the difference. All Good videos on the Cornwalls btw.👍👨🏻

[@chrispicquet733]

I'm with you 100%.I upgrade speakers constantly.i really enjoy it! I'm doing horn speakers now.(Klipsch Belle's, Hereseys,EV, and some JBLC53 libras.) Dampening the horns are essential.but the woofers that Klipsch has been using in their heritage series for some time have missed the mark(low efficiency,and serious roll-off in the upper bass/lower midrange regions.i found that using cast frame,high efficiency woofers seems to balance the system much better.i always pull those CTS woofers out of Klipsch's and replace them with Pro JBL stuff.it's just magic when modifing Klipsch speakers.

[@debragibson3489]

Hi Chris, husband here...for my heresys, what "pro JBL" stuff are you suggesting?.....Thanx in advance

[@chrispicquet733]

@@debragibson3489 Debra, the Woofers/Horns that are in the newer Klipsch stuff is Cheap stuff.Most people think that an upgrade is Newer,high tech stuff,but it is Not!!!.when it come to Klipsch, I Backgrade!! The Early Model H700 Heresey used the Electrovioce SP 12B woofer,K55v(Atlas) Alnico Mid driver w/cast mdl.700 horn.Electrovoice T35 Alnico tweeter

[@chrispicquet733]

@@debragibson3489 that is current configuration in my Heresey's.The JBL D123 work's great,but is pricey.(L100 woofer).in bigger Klipsch Designs,the Alnico JBL Pro 15's are critical( Le 15a,130a,2215,2220,150a,etc...make sure the us are cast frame and preferably Alnico.

[@chrispicquet733]

@@debragibson3489 Pro EV stuff is great as well.less pricey.(EVM 12L,voted best guitar speaker),EVM 12B, for Heresey's.For larger Klipsch's,EVM 15L,15B. Hope I've helped!! Good luck!!

[@SmilinMikeable]

Anyone try to place dynamite on the armor church of the woofers? I and mark I heard those have some resonance as well

[@edjackson4389]

You are so right about that last part! 😄My whole life I've been going thru that 'fixing one noise only to reveal another' thing

[@juy3541]

I did that with my RP-600m too. Added it on the tweeter housing, woofer basket, port tube and the inside of the cabinet then added the sonic barrier damping foam. Also changed the xover parts. Now it sounds way better.

[@thebostonaudiophile]

@@juy3541 Good to hear! Thanks for watching.

[@bthesac]

I love the horns on all my Klipsch. Never thought about changes.

[@thebostonaudiophile]

If you like them as is then keep them as is! Thanks for watching.

[@kevykev9957]

I’ve spent 10 years trying to get used to them. Music. Oh my gosh so good. Movies? Not so much

[@TTykwer]

If they ain't broke, and they definitely are not, don't fix 'em. Some people still don't quite understand that the entire stereo system, in order to get the most of it, should be well matched.

[@steveflor9942]

All the exotic plastics nowadays.... It is amazing that Klipsch wouldn't use a more acoustically inert material for their horns. Really no excuse for it. Thanks for this great video. BTW: Dampen - make something wet Damp - absorb energy

[@SpencersStuffTV]

They do on their rp series because they're made in china. By having these heritage speakers made in hope, arkansas, you're spending alot more money on labor and they have to cut costs in some places.

[@steveflor9942]

@@SpencersStuffTV That is good to know. Thanks

[@thebostonaudiophile]

Any single material may not work as well as a 3-layer composite, which is what the Dynamat (viscoelastic rubber and aluminum) on the horn creates.

[@deanm.rosenberg3847]

Spot on! Did the same with my Klipsch as well as the rear woofer baskets (less ringing?) and interior of the cabinets. Might say "OVERBOARD" but I appreciate it!

[@thebostonaudiophile]

Thanks. IMO it really changes the character, for the better, and resolution of the speaker.

[@CUSTOMWORKS7.3PSD]

I've been using automotive dynamat in many of my home made speaker projects and it makes a huge difference in sound quality

[@thebostonaudiophile]

I appreciate your feedback. What parts of your speakers do you put it on?

[@BlaineShillington]

I assume this would benefit nearly any horn waveguide. Great video!

[@thebostonaudiophile]

Thanks. That would be my guess, but without trying it and listening before and after, I wouldn't want to make that "any" assumption.

[@66doodz]

I’ve seen a lot of guys on the Klipsch boards who dynamat the woofer basket also and passive radiators. I’ve had a lot of fun experimenting with these mods on some older stuff just to see if I like it enough to do more of my better speakers.

[@thebostonaudiophile]

I was thinking of something different than just Dynamat on the baskets. Still deciding if I want to go there. The Dynamat is sure easy though and I bet it helps!

[@sentezle1090]

Dynomat should be ok. I have been thinking of making my own and dampening on the woofer (any woofer) was something I am considering. I had actually been thinking of some more extreme mastic/bitumen type product, but something that comes of with acetone would be better.

[@skip741x3]

ANYTHING that reduces or eliminates resonance in a speaker, whether that resonance be in the horn, the woofer basket or of course , the cabinet itself, will yeild a more true and pure sound reproduction..its all these combined resonances that Add Up to produce an overall diminishing of good sound...Very expensive speakers have taken great care to deal with these areas..Its the midrange and budget speakers that really need the help

[@66doodz]

@@thebostonaudiophile the old Infinity Column II's had 4 woofers and they literally ring like bells when you knuckle rap them. I cut and put damping strips on the baskets and then braced the part of the enclosure that resonated the most. I also damped the midrange enclosure. It was a huge improvement in those speakers. Low cost and low risk also for those speakers.

[@thebostonaudiophile]

@@66doodzThanks for your firsthand feedback!

[@bobbolles8028]

I just completed this process for Heresy I’s I aquired and the difference is VERY noticeable. Much more clarity and separation in the midrange. I can clearly hear every instrument and words sung. I only did the midrange horn, but WOW, most of the music is played from that horn anyhow. These are much better to listen to now… the strange resonance has disappeared. The problem was the plastic horn that easily resonated interfering with the sound in a particular range of frequency, unfortunately where much of the music is. Thanks so much for this presentation.

[@thebostonaudiophile]

You’re very welcome. Glad you’re pleased!

[@chuckmaddison2924]

I agree with what you have done. Putting the resonance of the horn below the range of what the speaker plays is within design ideals. So I would say the dude that designed it would be happy.

[@jefffeith4201]

Damped the tweeter of my Heresy IV with rope calk and heard an improvement. What I heard as sibilance must be a resonance in the plastic horn. With the tweeter resonance reduced now I can hear that resonance in the midrange so I will dampen it next. The speaker sounds more laid back and less ‘in your face’. No rush to do the midrange mod since the sound is already excellent… but when I have some time I’ll probably tinker. As you said, do it as long as it’s fun and when it’s no longer fun just enjoy as is.

[@johnvincent4048]

I recently picked up a pair of Forte ii from the 1990s at a very reasonable price and applied dynamat extreme to the midrange and tweeters just like in this video. I also applied it to the insides of the cabinets. Only about an 8 inch wide strip on each side. Top to bottom. I am driving them with a Decware 2watt tube amplifier and am stunned how much more dynamic the sound is. Especially the bass. Its full and rich. So this method does work. To my ears it did improve the sound. Thank you for the video!!

[@thebostonaudiophile]

Thanks for sharing your experience. Glad it worked well for you too!

[@johnroady9495]

Thanks for your videos. They're very interesting! I like how the Klipsch community embraces the upgrades, it learned a lot from the forums and my upgrades/mods really did a lot to bring them back to life. I recently upgraded my Klipsch Quartet with new crossovers and Bob Crites Titanium Tweeters and I'm very happy. Dean and Frank have never sounded better!

[@thebostonaudiophile]

You are very welcome. Thanks for watching and for your kind words.

[@drdiesel1]

If I didn't live 600 miles away I'd offer a few hours of quality craft beer in exchange for a listen to your system! Well done Sir.

[@thebostonaudiophile]

Thanks. The beer would be great, but I'd let you listen just to share my system!

[@georgieboy2432]

Nice to see a person with a positive outlook on life.

[@thebostonaudiophile]

@@georgieboy2432 Thanks for your kind words and for watching.

[@MIKK4081]

Great Tutorial, this improved the sound of my 4 RB-81II so much. I nearly sold them on ebay, but now they sound perfekt on higher volumes. They lost the annoying sharpness in loud "Party Mode", an i love to play them loud. Thanx a lot, and greetings from Austria.

[@thebostonaudiophile]

You're welcome. Glad you heard and liked the change!

[@jacekhabrajski8440]

I agree that it can improve, eliminate resonances. For me, these are improvements based on the placebo effect - because I can't hear any difference after damping, but when I connect another receiver to play, the sound always changes. This is the way of IMPROVEMENT, on the proper matching of system components and their synergy ...

[@maconpatton]

I put. dynamat on my oe Bose sub box in my Porsche & the bass sounds much better. I’m concerned that you have affected the balance of the low frequencies to the highs. I’m certain the driver screwed into the enclosure dampens if significantly. Glad you are having fun.

[@lilah66]

Would a spray on damping material have any downside? I just acquired a pair of AK5 and converted them to a B profile and plan on trying a mini dsp 4x10 with 6 channels of old McIntosh tube amps and see how that goes. The Khorns will be used mostly for old movies with optical soundtracks. I would have loved to use Western Electric horns but they are the size of a car and cost as much as my house.

[@nicevmax]

I will be recapping my 1989 Forte II's and will be doing this very thing to the horns. It just makes sense, and can see why they would sound better and cleaner. Thanks for the vid.

[@thomasshannon9662]

I did a mod on my R 820 F and my R 51 m surrounds by lining all the walls with thick polly fill. What an improvement. Tighter bass no more muddy sound and in that process I could hear my mids better because all that cabinet resonance went away. Next will be your horn modification. Thanks ..

[@raphaelness1239]

What is poly fill? I have some r52 towers I may want to do this with...

[@oddingardleirvik4781]

I know what you are talking about. I did that to my old car doores that i had installed 8" whofers and tweeters, and no one can tell me it didn't make a differense. By the way , it was stolen and wrecked and i never did it again.🙂 what you do to theese horns i beleve is even more effective.

[@pablohmleyton4552]

After seeing your video, I thought, "Of course! Why didn't I think about it before?" I've used Dynamat in my car and it works wonders. Great callout and good job on doing the video.

[@bennyaudioturntables5416]

This mod is absolutely a good one. Great job. I tried some foam behind mid horn but this was a mistake. Guys from klipsch know how to make an excellent speakers.

[@thebostonaudiophile]

Thanks.

[@sentezle1090]

Interesting.

[@midnightsunindustries5239]

I've got Forte 1s, am thinking of treating the horns (I've heard No-Rez works great too, not sure how it compares to Dynamat). It seems like there could be another nice improvement by bracing and damping the cabinets too. My crossovers are probably a bit diminished; I'd like to either rebuild the stock ones (circa 1985) with new caps, or I could also go 6 channel active via mini dsp and delete the crossovers all together. Even like they are, I sure love listening to them : )

[@tedrubinstein2003]

I dampened my horns this weekend and it did seem to give better seperation of instruments especially times when more instruments are playing. It also seemed to make the sounds even more clear and clean. Thank you very much for doing the leg work for us. To tighten the bass up even more and keep the sound clearer at high volumes with a lot of things playing I am concidering pulling the bass speakers and treating the metal baskets with the Dynamat and I'm not sure the best way to brace the sides of the cabinets or the best way to dampen cabinet sides with wool or no-rez without taking away the livelyness of the speakers. If anyone has tried this or has any other thoughts I sure would appreciate them. Thanks Ted

[@Hugeroost]

Ted, what did you find out

[@tedrubinstein2003]

​@@Hugeroost Other than moving them around a bit I haven’t touched them since. I did however get a new Parasound Halo A52+ Power amp to use with my Yamaha RX-A1080 receiver. Added Great pop and clarity to the sound.

[@Hugeroost]

@@tedrubinstein2003 cool deal, I'm considering hooking up my yamaha B2 to mine and see how that sounds. I have read what a great combo that is

[@keeferdog5617]

Steve Guttenberg recently featured an audiophile that used Dynamat on the inside of the case of a Cambridge Audio CXC cd transport. He made several other changes but felt the Dynamat helped reduced resonance during playback. I own a CXCgreat transport for the $ and have thought of adding the Dynamat too. We’ll see.

[@theklipschcave5593]

Yes I saw that one. good tweaking that made sense. Do look into damping mats to decouple your speakers from the floor to regulate the bass sound. Auralex under my Fortes makes a difference on top of transport dollies like Darko use on his Fortes and Boston Audiophile use on his Cornwalls. Not to forget the need for raking. Slight tilt upwards can make a big difference.

[@keeferdog5617]

theklipschcave Didn’t Darko put his Fortes on a wooden frame with 4 caster wheels? Like a moving dolly? I owned a pair of original ‘86 “Oiled Oak” Fortes. They were paired w a good ol Marantz 2325 125w receiver. Nice combo. Really enjoyed it...

[@theklipschcave5593]

@@keeferdog5617 Yep. Wooden frame, or a transport platform bought in a hardware store like mine. But I do have Auralex damping mats to decouple the speakers and the bass from the floor. They really make a difference. I been lokking into the Dynamite tweet. All carprople use this. Cheap and effective. Probably good combo with a damping mat under my CD-player and tube amp.

[@amusikpoem1071]

This is some excellent and detailed work here...it takes alot of patience and you have it...thanks for sharing!

[@thebostonaudiophile]

Thank you. Glad you enjoyed it. Thanks for watching!

[@johnjuhasz3913]

I have not done this yet on my KG4s but, I can say that fully encasing the horns (or anything for that matter) is not necessary to dampen the resonance. I know this from my experience in the auto industry. Just as you can kill the resonance on a surface by laying your finger on it, you can do the same with a strategically placed piece of the dynamat. The extra material probably does no harm but, you do not have to go to the trouble of cutting pieces to fit the exact shape and contour.

[@thebostonaudiophile]

I agree with you. Excellent point! If I were manufacturing a speaker, I wouldn’t take this whole coverage approach. I wanted to be sure I damped the whole surface, which is overkill, but gave me peace of mind that a little more coverage wouldn’t produce better sound.

[@timothymoorman7437]

I very much enjoyed your treatment of the horns, but wondered if the same logic had extended to lining all or part of the cabinets with sound deadening material?

[@thebostonaudiophile]

Glad you enjoyed it! Yes, there are undoubtedly several other parts of the speaker that could use damping and/or sound deadening.

[@NickP333]

Great parallel between car issues and HiFi gear. I know the struggle all too well. 😂 lol

[@tedrubinstein2003]

I did these mods to my Cornwall 4’s about a year ago seem to work well. I was considering doing the Dynaman extreme to the side walls and possibly backside of front baffle and bass baskets. Has anybody done this on the Cornwall fours. Don’t know if it will do anything. My biggest caution is that I don’t want it to kill the open airy dynamics of the speakers or make them sound dull or muddier. Could use No-Rez but I believe it’s thicker don’t want to mess with air flow.

[@andregunther1995]

After a few months now.. Do you still recommend this treatment? Is it the better sounding speaker compared to the untreated one?

[@thebostonaudiophile]

Yes.

[@Grooverski]

Finished (Dynamating) 2nd speaker just now. Astute modification that is ridiculously easy to execute and super inexpensive. A must. To my ears, result is substantial and positive. Thanks!👏🏻👏🏻👏🏻👏🏻👏🏻

[@thebostonaudiophile]

You’re very welcome 😉. Yes, it makes a big difference. People think everything is a “tweak” but the horn damping is a major improvement to resolution as well as musicality. Enjoy your speakers and thanks for watching.

[@Grooverski]

@@thebostonaudiophile Yes it is. BTW, I just ordered Sonic Barrier 1" acoustic foam to cover inside walls of Cornwalls. I'll test it next weakened. Goal is to smooth out bass resonance inside the speaker. Also, have you considered using dynamat on bass stamped basket and those 3 flared bass ports???

[@rd264]

@@thebostonaudiophile why wouldnt Klipsch put these damping improvements in stock speakers?

[@irisonray1]

@@thebostonaudiophile - Hi did you add any sound damping material inside or dynamat the woofer baskets and/or the bass ports at the bottom? Thanks!

[@conduit242]

@@Grooverski Did you end up doing this? How does it sound?

[@ScottsLifeOffGrid]

I am curious if you ever put the dynamat on the metal frame extensions on the woofers? Thank you!

[@thebostonaudiophile]

@@ScottsLifeOffGrid Not yet.

[@myplacerighthear3691]

I've been buying listening and owning Klipsch speakers since 1974 and I've also used other speakers from other companies from about 1978 to present day August 2024. And I truly loved them all because I owned them all and always coming back to Klipsch. Specifically the Klipsch forte model 3. The model 3 of the Klipsch forte is the absolute sweet spot of all four versions released. And I never had them modified there's no need to if you have a really decent AVR or amplifier the Klipsch forte model 3 will dance for you and give you the most wonderful Sonic abilities you've ever heard depending upon the room size recently I've had The Good Fortune of being able to put together a 9.2 surround sound system of which the LCR is forte model 3.. and then using the 8060 Faz for rear channel and finally the 8000 f Mark II to round out hype channels surround sound channels. However the speakers are built and come to you in boxes leave them that way.. and if you ever have the chance to do what I've just mentioned in this post please do you will be very pleased and very happy with your listening stage or what some may say a wall of sound. Klipsch is keepers of the sound.. now may we have everything sonically smooth enough all the time everywhere. Thank you and enjoy.. please don't obsess about upgrades too much because in time it just may ruin your ability to discern to own to possess greatness in sound😊 .

[@dougg1075]

Very cool but I’m wondering if the lively ness of the horn is not part of the design instead of a flaw or shortcoming.

[@thebostonaudiophile]

The sound is still plenty lively, in fact, it's more dynamic after the mod.

[@hochgonzalo8923]

Quite frankly, material cost plays a huge role in design.

[@kohnfutner9637]

Anyone who thinks you or danny Richie know more about Klipsch's speakers than the manufacturers and designers themselves are in for a let down I have a feeling. This is about like when I was 19 and modifying my car only to realize I should've left it alone. I know a lot of people don't believe in break in and I am not sure I do, but it seems like after 1 year with my Klipsch system, it is sounding so much better than it did in the beginning. At first, I was not happy at all but now I'm in love and a very big advocate for Klipsch. I've put many hours on them, my whole family uses them, so a lot of hours at around 70-80db. A year later, just today I bought 2 rp-250s to finish my surround sound because these speakers are just so good, so good it's unbelievable. If the 280f costed $3500 they would get much more credit than they do. Lucky for us, they're only $800 a pair, the center 450c for $400 is unbelievable, great deal, amazing center, the first real center that can actually take on the demands of a center channel that I've ever used can actually get the voices right and delivers deep beats and the Dynamics of real life instruments and cinema action.

[@eccentric363]

Kohn, with the horn mods the only negetive I could imagine is that, the crossover was designed with the horn resonance present. take away this resonance and there could be a dip in the response at that point. that's all. I think the sound should actually improve. Horn resonances aren't part of the music. Everything is built to a price, and I reckon Klipsch should have gone the extra mile and implemented somtehing like this themselves.

[@thebostonaudiophile]

Mods aren't for everyone. It's fine to leave them stock. Still a good speaker!

[@vncstudio]

@Kohn Futner Agreed. It has taken several hundred hours with my Cornwalls plus small position adjustments and suddenly everything has snapped into place with solid bass even from a 6 watt SE amp. Moving the speakers even by an inch towards the wall changes the amount of bass.

[@mattfranklin3622]

Retail loudspeaker designers work to a marketing strategy and a budget. The original design might well of had these mods done by the prototyping team but them removed them to bring into budget. Simply saying you don’t know better than the designers is gobbledygook! If these were the best they could possibly be why did they feel the need for a mk2 or 3??

[@lukaingo4650]

Hello, when you play music with tight bass, do you have tight, relaxed or boomy bass with the Cornwall IV? Thank you

[@jeffbrooke4892]

Great video and great approach to describing sound/noise awareness as things get "cleaned up." Thanks!

[@danielgrossman3956]

Thanks for this awesome video! A few months ago I bought a Forte III, and I must say I am not enjoying them very much. I find them very jarring in the high-mids, especially brass instruments and certain vocals can be very fatiguing and harsh. On the other hand, they lack bass and mid-bass in my opinion. This is a new pair which cost a fair bit of money and I am worried about hacking it without any experience, but do you think this type of upgrade may tame that shouty top? I'm also going to experiment with some tube rolling and cables, but wondering which upgrade will have the highest impact?

[@TheStarflight41]

What about treating your room to absorb some of those high frequencies... there are many kinds of treatments including DIY.

[@franimal007]

I have been thinking of doing that to my RF7's first generation speakers, seeing this, I now will get to do it.

[@thebostonaudiophile]

Kindly note my precautions in the video description above.

[@BobMelnik]

I just did this to my RF-7s (Dean G Xover modded), last night after watching the other video. I don't know how to describe it well, but lets just say, I'm now more excited to listen to 2 channel stereo than before.

[@jefffeith4201]

Has anyone tried damping the diaphragm? Taking it out and coating the inside with something to reduce resonance? I’ve already damped the back of the plastic horns to good effect. Just wanted to see if this tweak can be brought even further.

[@mkshffr4936]

This may be why wooden horns have such a good reputation. I have used duct seal to dampen speaker baskets. Is dynamat more effective?

[@thebostonaudiophile]

Could be a plus for wood? I didn't use the Dynamat as a seal but as a surface damper. The enclosures are ported anyway so I don't know if sealing would make a big difference or not.

[@mkshffr4936]

@@thebostonaudiophile I use the duct seal as a damper. It is like a thick putty of fairly high density so damps some of the ringing.

[@fredbloggs6080]

I haven't checked your channel completely, but have you done other upgrades in the electrical path, such better inductors, capacitors, resistors, and replacing steel terminal parts, etc.? Following the logic of your horn dampening, I was wondering if packing a singer's nasal cavities with cotton would improve their sound by reducing resonance in the mask..

[@thebostonaudiophile]

@@fredbloggs6080 Changing the recorded source isn’t the same as removing colorations in the playback chain.

[@fredbloggs6080]

@@thebostonaudiophile I wasn't suggesting that as a better source for recording, I making a joking analogy between damping a horn and damping singer's nasal resonance. Have you heard the Volti Rival? A Cornwall copy design that supposedly uses better components and cabinet build etc. The designer says he doesn't care about measurements and doesn't pay attention to how his speakers measure, he just goes by what he likes when he listens, so he may like certain colorations and apparently a certain number of people like that too in his speakers. Is it possible some people like the existing colorations and the Cornwall IV over what happens when they are modified? I'm just asking, just as you put the disclaimer on the modification of damping the horns.

[@shannonwilliams6623]

Add dynamat on the metal frames of the woofers to help with resonance, cast is different then steal and those look like stamp steal, also solder your wires to your speakers and get rid of the 5 way binding post and convert to tube connectors for your banana plugs to ensert into, then solder them directly to your speaker cables, the hardware on your original set up is bad for sound and restricts performance, did it to mine and it was a night and day difference.

[@thebostonaudiophile]

Thanks for your suggestions and for your first-hand feedback (with a different speaker, I assume).

[@marcopignone9386]

Did this to my Forte IIs and I did notice an improvement. Slight, but noticeable, and I assume that the difference would be more significant in a higher resolution speaker like the new Cornwall IV.

[@chrispicquet733]

There are some really good woofers that make great substitutions.The Goal: Increase the Mechanical Damping Factor,and The Efficiency of the woofer,by using a driver with a larger magnet,and cast frame .In doing so, The tonal balance,and cohesion of the system will result in more seamless, balance. The cheap stamped frame drivers are less efficient,slower,and cause unwanted cabinet anomalies.EVM 12L's,12B's JBL cast 12's are my top choices.

[@vuxnguyen]

hi! anyone know what is the midrange driver throat size? thanks

[@Grooverski]

Awesome. How much material do I need to order to finish both horns on 2 speakers?

[@thebostonaudiophile]

I used this (18x32"): www.amazon.com/gp/product/B00020CAVA/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 which was enough for both speakers with a bit to spare. Remember to mark the wires and horn terminals so you get it put back with the crossover connected to the right drivers and with the proper polarity. Also, the Dynamat sticks really well, so I would consider it non-reversible. Good luck!

[@Grooverski]

The Boston Audiophile Thanks a lot. I’m going to follow your journey and start working on these mods. Seems pretty straight forward. What are you planning on doing next, cabinet bracing? Seems like a next logical step before diving into crossovers. If you are going to mod your crossovers, can you do a detail step by step process and parts list? It would be very helpful. Great work as always. 👍👍👍👍👍👍👍🙏🏻

[@thebostonaudiophile]

You are welcome. Please read my cautions in the video’s description. Good luck!

[@djmorgan8783]

What was wrong with the bass will it not get down low

[@keithazz5103]

Brilliant idea, even with new models years after this video would be helpful too. 2023 RP-8000F II with the rubber on the front, but nothing on the back. 💯 👍

[@thebostonaudiophile]

Thanks for watching and commenting.

[@Mickparrysstepdad]

Everything vibrates at a certain frequency, so it makes sense to try and damp it when it's in the audible frequency range (especially so when it's at higher frequencies). When a note plays that is the same frequency as the resonant frequency of the horn, it will join in and muddy the sound. I didn't see any foam on the back wall of the cabinet, so it would be worth experimenting with acoustic, open cell foam. Obviously keep it well away from the ports. Advantages are a tighter, cleaner low end, disadvantages can be less bass if you go over the top.

[@petersouthernboy6327]

Overdamped bass reflex cabinets introduce a fresh set of issues. Stiff cabinet walls and high flowing, low noise ports are the ticket with bass reflex 👍

[@dougg1075]

I wouldn’t go overboard and kill the cabinet

[@Mickparrysstepdad]

@@dougg1075 A speaker is not like a musical instrument that produces its own sound. It's supposed to reproduce sound.

[@thebostonaudiophile]

Yes. That's a good explanation.

[@rickg8015]

Oh yeah, forgot about Dynamat.. You could use that for the stamped steel legs of the woofers too. Great job!

[@thebostonaudiophile]

Thanks for the tip. I'd like to research woofer basket rigidity and damping.

[@AmmoDude]

I tried this dampening with my KG-4 horns. My results were discouraging; it took all the brightness out of them and they sounded dull and nasally. I removed the dampening and the brightness returned. I did however use a gasket material around the screw flange and that seemed to do the trick for me.

[@thebostonaudiophile]

Sorry to hear that you didn’t like the results. I’m not familiar with the KG-4, but your ears are the ultimate judge for your system.

[@AmmoDude]

@@thebostonaudiophile Plastic horn with soft dome tweeter.

[@DA-ou7hv]

Makes perfect sense to me. You don't have to be a sound engineer to figure out the economics of brand name speakers. Er....you don't have to be an accountant....sound engineers just do what they are asked to do....Yes interesting video and great job. Thanks.

[@SuperGeorge2112]

Another great video , you wonder why can the manufacturer not do this at design and manufacture. if they are all about sound quality. it will make a huge difference.

[@geol7408]

Do you still use the Cornwall's and if so, what are your long-term impressions? Are you still happy with them? I'm getting ready to do this to my pair and was wondering. I just subscribed so I don't miss your response. thanks!

[@thebostonaudiophile]

Yes, I'm still using and enjoying the Cornwalls. Yes, the mod is worthwhile and I still like the effect. Be sure to use Dynamat Xtreme and not some other look-alike product, or I can't say how your results will be. Thanks for subscribing and for the good suggestion to do a long-term impressions video. It's something I've thought about, but maybe I'll make one in the next few weeks.

[@oldestpunkinargentina7766]

Will this work on the tweeter horns of my F2s ? Thanx ! Wonder if it's such a cheap mod, why is it the manufacturers don't dampen the horns at the factory ?

[@robertbuskop4987]

Proper damping is costly. The best horns from Western Electric, Philips and other top makes were completely double walled with the interior space filled with fine sand! If you've ever heard a W.E. "multichanneled" cinema horn you're spoiled forever!

[@thebostonaudiophile]

I expect so. I can't comment on why manufacturers don't do it. Perhaps they feel it's not cost-effective (It does take some time = money) or that their customers won't value the difference?

[@ELVIS7198]

I plugged my cornwall in bi-wiring on my rotel Michi S5 + P5, I took two 4mm cables of diferante brand, the sound that comes out is really incredible, I would really like to listen to your cornwall with the modifications you make , thank you for your always very interesting video.

[@thebostonaudiophile]

Thanks for watching. I want to try bi-wiring at some point also, so I appreciate your insight. There are many things I want to experiment with but it’s important for me to take it slowly and give myself plenty of time to absorb and readjust to system changes. Otherwise, my impressions will become a muddled mess.

[@joshuaschneck]

Hi. I recently added a pair of Klipsch Forte IVs to my system. I really like the sound of the speakers - thinking about trying your modification. How did you pull out the drivers? Do you need to solder anything? Thanks, Josh

[@thebostonaudiophile]

Thanks for watching Josh! There’s nothing to solder. All three drivers are held in place with Torx, socket head cap screws. There are two push-on connectors to each driver, which can easily be removed by hand. Be sure to note which wire, red or black, goes to each terminal and which wire pair goes to each driver, just to be sure that you get every wire back to the right terminal when you reassemble the speaker. This is very important! I strongly recommend that you use the same Dynamat material that I used. It’s important to create constrained layer damping. Spray on rubber, Mortite, etc will NOT be as effective. It’s not difficult but it takes some patience. It may be easier to lay the speaker down (drivers up, binding posts down) on some cushioning, like several towels, when removing and replacing the drivers. Proceed at your own peril. 🙃 Obviously, I don’t know you, some people are good at this sort of thing, others not so much. Good luck!

[@joshuaschneck]

​@@thebostonaudiophile Thanks for the tips. I've used similar adhesive material (Noico 80 mil... from Amazon) to sound proof the air ducts in my house so I have a good idea of what it's like to work with this material. Surprised that Klipsch didn't dampen the horns in the factory since it seems like a relatively inexpensive step to implement. Did you ever get a reaction from Roy Delgado??

[@thebostonaudiophile]

@@joshuaschneck You’re welcome. The Noico 80 looks similar to the Dynamat but I can’t tell for sure if it would be equally, more, or less effective. I’ve only used The Dynamat I showed in my video. I found this comparison but it’s a different application: soundproofliving.com/noico-dynamat-review/ Since it would be extremely difficult to remove, I’d stick with Dynamat but the Noico might be fine too. I just can’t say.

[@joshuaschneck]

@@thebostonaudiophile Thanks again. The only thing that is giving me a bit of pause on this project is the possibility that the internal resonance of the horns might actually be part of the sound that Klipsch speakers are known and loved for....? Probably not, but it's a bit strange that Klipsch didn't put some dampening on their horns in these $5-6.5k speakers. Any thoughts on this?

[@thebostonaudiophile]

@@joshuaschneck If you have reservations, then I would respectfully suggest that you leave your speakers alone because it would be very difficult to reverse if you don't like the effect.

[@nathanielbullock3939]

I guess that is the question I want to ask , after months later do you still feel the mod was a good effort.?

[@thebostonaudiophile]

Yes. Absolutely.

[@atulnsingh]

REALLY ENJOYED THE VIDEO. Watched 3 times over in the past few months. I am now getting too tempted to do the dynamat thing on my Forte III but a bit afraid 😦

[@thebostonaudiophile]

Thank you. I'm glad you enjoyed it. I understand your apprehension because it's not reversible. Please read my precautions in the video description (above). IMO the benefits made it very worthwhile and the cost was only about $30. It does take several hours and everyone has different levels of experience when it comes to this kind of project. Good luck f you decide to go ahead! Let me know how it goes.

[@tedrubinstein2003]

If the comment below was intended for me he could be right looking to modify perfectly good new speakers, but this was an awesome video going over the details to make it happen. If you see this Mr. Boston Audiophile or anyone else that has dampen the horns can you let me know if this takes away the live performance feel the speakers give you. Thanks Ted

[@klepp19]

I have seen many videos of people taking out the horns say on a Forte or Cornwall. But it seems the paint is always ripped off on the lip of the hole. Do you know what black paint Klipsch uses to replace missing paint before putting back in the horn?

[@tedrubinstein2003]

I don't know what kind of paint they use but when I did mine no paint came off.

[@Thomas..Anderson]

Another interesting experiment would be to replace iron core inductors with air core inductors and orient them 90° to each other in 3D. Another step is to apply Dynamat or similar constrained layer damping onto cabinet walls and a piece of carpet or layer of acoustic absorbent foam over that.

[@thebostonaudiophile]

Yes. There's a lot of other things one could try.

[@sentezle1090]

Yes there are other things, but maybe on atleast tweeter and upgrade the resistors. To build all new boards to that quality would be hugely expensive for an experiment, because you would not want to cannibalize the originals. I would rather build stronger cabinets with less resonance than buy new cross overs.

[@toddstyles7194]

I will leave my Heresy IV just how they voiced them. Just like Harbeth speakers. Cabinet's resonate like they're soppose to and I'm sure they are not filled with dynamat mat.😏

[@wfranklin990]

I have a couple of problems withe the approach here. First, on the illustrative "tap test", it does not account for the damping of the horn resulting from proper installation in a baffle with a closed cell foam gasket. I'd guess that you'd get much less ringing from the "tap test" and imagine that was taken into account by Klipsch's designers. Second, recognize that the sound of any horn is the result of both the signal introduced at the throat of the horn, as well as the resonant characteristics of the horn material. Try applying Dynamite around the bell of a trumpet and see what you get; definitely a difference, but not a pleasing one and certainly one which alters the fundamental nature of the trumpet's tone. Note that I am an advocate of damping in the right places in/on a speaker, but am not sure deadening the horn is the best approach. (Musician, and yes, I've built my own horn speakers.)

[@thebostonaudiophile]

The horn damping definitely improves the speakers. Your suggestion may improve them further.

[@jeremiahbignell3161]

Did this to my kg 5.2s and it very noticeably killed a lot of the high frequencies. Gonna un dampen them.

[@chipper2462]

I think using dynamite is an excellent idea...😀

[@mondoenterprises6710]

I think I may try some rockwool in the upper cabinet of my la scalas and see what the difference is.

[@barryhallsack8852]

I just bought some cornwalls 4. I will be doing this to mine thanks for sharing awesome video!

[@thebostonaudiophile]

Congratulations! You may want to get familiar with them as is, before the mod, so you’ll fully appreciate the effect of the damping. Enjoy!

[@LatinPerspective.]

In my opinion any upgrades to a klipsch makes them a klipsch only in name. The sound of klipsch heritage speakers were approved by the ears of Paul W Klipsch.

[@phatrayray]

This is bullshit......you honestly think there haven't been improvements in the last 60 years? If what you say is true then why isn't klispch still using A or AA networks? What about klipsch changing the horn material from aluminum to composite? Besides, there are no 2 rooms with the same acoustics so your point is completely moot.

[@LatinPerspective.]

@@phatrayray Did I hit a nerve? Any change you or Klipsch make to the original heritage speakers mean that the new sound is approved by the ears of Paul W Klipsch. The original heritage speakers were VOICED with their original parts. Any new part you put in a heritage speakers will change the speakers original sound. New Parts will make them sound better or worse but not the same. I own the Klipsch Chorus II, if I can find a new pair of the Chorus II with all of the original parts brand new I’ll be in heaven.

[@thebostonaudiophile]

Nothing wrong with leaving yours stock if that's what you prefer.

[@herrtrigger7220]

Apply a thick layer of silicone caulk covering the inside area of the horn. Let each flat area dry and apply another layer. Better damping than the panels, cheap and available everywhere.

[@kentonkirkpatrick5225]

I'm wondering if using some Flex Seal spray rubber would be as effective with 1/10 the work? How hard is it to completely detach the plastic horn from the driver section? Klipsch could sell the plastic part to modders to replace mods if they don't work out.

[@thebostonaudiophile]

Flex Seal spray will not create constrained layer damping (Dynamat is a viscoelastic rubber with an aluminum constraining layer) which is critical for high-performance damping.

[@flyboymcgee8059]

Going to be doing this to my several pairs of Klipsch speakers. Also, investing in new foam for the interiors wouldn't hurt on vintage pairs. Materials degrade and lose density over the years

[@thebostonaudiophile]

Let us know how it goes!

[@seasterl]

I’ve seen a similar modification to older Klipsch. Did you do this because you thought the midrange was too hot/bright/forward?

[@thebostonaudiophile]

Not exactly. I wouldn't characterize the Cornwalls as particularly bright. I was after more resolution, timbre accuracy, and control by taming the passive colorations of the horn.

[@bthesac]

Have some old school Heresy speakers. I have dynomat extreme all over my car. Love the stuff and it works. May do that for indoor audio too.

[@thebostonaudiophile]

Nice!

[@larsbiagio367]

Could this be done with some "spray on" product?

[@thebostonaudiophile]

Good question. I don’t believe so. One needs to introduce “constrained layer damping” for the best effect. I’m not saying it couldn’t help some, but constrained layer damping is more than adding mass. Constrained layer damping forces the viscoelastic layer to shear and that attenuates vibrations extremely effectively.

[@PC-uh6hk]

A friend of mine sold me a set of Klipsch speakers for $50 because he was downsizing his possessions. I think they are from the 1970s but is there a way to tell what they actually are? I've never opened the back of them.

[@thebostonaudiophile]

Congrats! Isn't there a label on the back?

[@Staybrown11]

Have you “upgraded” with No Rez in the inside of the cabinet? I’m thinking of doing this on my Heresy 4.

[@thebostonaudiophile]

I have not. If you try that, let me know how it goes!

[@skip741x3]

Fascinating experiment and very plausible results...makes complete sense and is like something I ,myself might do... I have klipsch speakers also, specifically the sf1 towers... picked these up cheap but found them harsh with a too prominant midrange and very bright topend... they take some getting used to and or lots of audio adjustments, at least for my ears!

[@thebostonaudiophile]

I’m not familiar with the sf1 towers but it may help. If they’re too bright, try increasing the toe- in so they’re not pointing right at you but instead cross ahead of you.

[@gerardopadilla4393]

Recommend for klipch rf7?

[@alfredbaxter1061]

I got techniec speakers they 4 12s tall with 2I’m thinking about putting horns on them

[@Quietprofessional1]

Will this work on my Klipsch RF-82 gen 1 speakers? Thanks!

[@thebostonaudiophile]

I’m not sure. If the horn part of the 82’s is a hard, molded plastic with a smooth rear, like you see in the video of my Cornwall’s, I would think that it would work.

[@keeferdog5617]

Any updates on a F7 review. Hows the synergy with the F7 and your Cornwalls?Thanks

[@thebostonaudiophile]

It’s coming. These videos take time. Thanks for your patience.

[@mark63366]

I really enjoy your video's. It's nice to see someone who isn't afraid to make improvements to their gear. Keep up the great work!

[@thebostonaudiophile]

Thank you. The purpose of my channel is to work towards hearing better and getting the most out of our systems, no matter the cost or specific type of gear.

[@elnericoo]

What is that horn made of? It looks and sounds like plastic? I have Cornwall I and they seem to have metal horns so I don't know if this mod will benefit me.

[@thebostonaudiophile]

Yes, the Cornwall IVs have plastic horns but older Klipsches do have metal horns. I would think the Dynamat would really improve those metal horns too but I haven't tried it, so I can't say for certain. If you try it let me know what you hear!

[@jwester7009]

I was wondering what issues you experience in the bass region now that you've upgraded the mid range?

[@thebostonaudiophile]

J Wester Since dampening the horns, I’ve made other changes to my system, not the speakers, and the bass is sounding quite good now. I plan to follow up in future videos. At present, I need a new computer before I can make new videos. Thanks for your thoughtful question!

[@dinhduynguyen3809]

Again great video! YT needs more of hifi DIY videos

[@thebostonaudiophile]

Thank you.

[@tombrennan6312]

Is this alleged improvement objectively demonstrable? Can a 1" compression driver produce enough energy to excite a horn wall? Note that many Altec enthusiasts report that simply bolting a 511 or 811 horn to a baffle damps resonances caused by tapping the horn. And Altec used freestanding 811 and 511 horns without damping on the horns. However when using large format 1.4" drivers such as the 288 Altec did apply damping to horns, going so far as to use tar filled enclosures for early multi cells. I think many people damp horns because they can. I put little stock in reported subjective improvements--having bullshitted myself I'm confident in the ability of others to do so.

[@thebostonaudiophile]

Good to be simultaneously skeptical and open minded IMO. I’m confident in what I’m hearing but don’t take my opinion or anyone else’s as gospel. Good luck!