Understand d'Appalito speaker designs

The d'appalito designs are unique in speaker topology and often popular amongst designers. Why do they exist, what do they accomplish, and how do they work? Have a question you'd like Paul to answer? Go to www.psaudio.com...
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[@tinkwilkinson9446]

I have a properly designed D'appolito system. Exact distance between speakers and purpose built crossover. Vendor provided drivers and crossover and plans. I built cabinets. I am an accomplished woodworker. Speakers came out great and still in daily use since being built 20 years ago.

[@afj617]

My father, Leon Janikian, had a studio called Sound Techniques in Boston for years. He was an early adopter of digital recording but can’t stand the whole ultra high end world. He loves Paul and these videos, however.

[@treyhorn5645]

Thank you Paul for all your wisdom . I am in Orlando FL . It's great to wake up every morning and have your new video to start my day. I am looking forward to my first purchase from PS Audio . I have watched every video and subscribe to your publications . Your love and dedication to your company is second to none.

[@kevinroosa1315]

D'Appolito MTM designs are quite nice. KEF used this implementation on their Reference 104/2 loudspeaker back in the '80s, and it worked very well.

[@rickc2222]

Paul, your voice is so calming and easy to stay focused on - I think you should turn your book into an audiobook version and do the voice-over yourself!. Bonus is you already have the studio to do it in!!! Plus audio book version could be a lot of fun with bonus content because you could provide audio examples of many topics discussed!

[@pcnj50a]

Hi Paul, a couple of comments. First, the M-T-M configuration wasn't original to Joe d'Appolito, it was first done by Koss- I think Robert Ashley did that design. What Joe figured out was that he could get the lobing control he was after if he did the M-T-M *and* used an odd-order crossover (e.g., 1st order, 3rd order...). So a "d'Appolito configuration" is actually M-T-M plus odd order crossover, not just M-T-M alone. Second, somewhat ironically, Joe found out years later that the configuration worked better with a higher crossover slope, with even order working just as well, and his later designs used 4th order Linkwitz-Reilly crossovers (sorry to go geek jargon-y). And please, next time you're drawing, use a Sharpie so it shows up better on camera. ;-)

[@bal20]

Im really enjoying hearing your expertise on all elements of speaker design and sound. One day hope i could afford a decent hi end system, but until then i'll continue experimenting making my own stuff.

[@InsideOfMyOwnMind]

Keep doing that. You never know when you'll come up with something better than what you can afford and what you learn in the process=priceless.

[@claesmalmberg7925]

As always great explanation and kind of fun. Keep up, this is great stuff

[@garbagemanify]

Hi Paul, Can you elaborate on how to design the crossover points, slopes, speaker spacing, and physical length of the wavelengths of concern on the D'A?

[@Ciiads]

I would love to visit but I can't, I'm very far away and have nothing to travel that far but one day I will 😔🤗

[@michaelireland7239]

love your videos paul & your sesnse of humour

[@roberthaysley4245]

That is the same idea as stacked Advents 40 years ago

[@mimikubacki4859]

Or today, Robert,a great arrangement and quite musical even today!

[@bjtaudio]

I've tried a few d'Appalito speaker designs and find the mid drivers cancel each other on the vertical axis, so it seems to work fine provided you're in line with the tweeter, but if you stand up a big null appears in the response, also since there are two mid bass drivers doing mid-range they cancel each other below the crossover frequency. So depending on listening position it sounds dull and muffled, as the drivers move in and out of phase with each other as the listening position changes. So d'Appalito speaker designs do not work! The trick to fix it is 2 only send bass to the bottom driver and midrange and bass for the top driver.

[@kolinstallman3788]

Im going to have to be a videophile to see what you are drawing lol

[@idtubenod]

Paul...just a clarification, since low frequency is non-directional would it matter - lobing due to the high frequency?

[@olerasmussen374]

Typical crossover will be around 2kHZ (not low frequency)

[@bjtaudio]

If you search youtube you will see videos on this. Where the same horrible cancelling issue occurs when you have 2 or more drivers in a vertical array, all doing mid-range and treble, it doesn't work at all!, they cancel each other, and it changes depending on listening position. In PA arrays one fellow put a bow tie wave guide over the driver to stop the cancelling to some extent. The trouble is the drivers are spaced apart and the distance to the ear are different, It only works at low frequencies where the wavelength is so long the drivers sum as one, good for bass not mid and treble. To get tweeters to work they need to almost on top of each other, impossible, can be done with ribbons as its a slot where they need to form a continuous slot 5 feet long. designing an array is not easy, so stick to a point source a lot easier to design..note you can stack drivers for bass up to a few hundred hertz where most of the power is anyway. But only use one mid and tweeter.

[@soulchorea]

Resurrecting an old thread, I suppose....but what if our friend in Australia did what he's describing, but with D'Appolito speakers? Would they be even moooorrre D'Appolito'd? Like more "cancelled out" of the lobe-ing effect?

[@darinbrunet4600]

Hi Paul, nice video at 3:08am 👍

[@souhailla10]

hello sir, it would be nice if you also could show the difference between a crossover for a 2 way version or a d'appolito filter system... and how to conect them and if the components will stay the same. regards roberto

[@souhailla10]

i quess not then . perhaps anyone else like to respond on my question please ?

[@balrajacharya]

Whats meant by alignment of speakers ? How it doesn't affect in horn loaded tweeters ? Balraj S.Acharya. Mumbai, india

[@ronnietjikoeri9965]

I think he means a real appolito designed speakers has the woofers same distance from the tweeter in the middle. He talks about putting 2 speakers on top of each other. And it should be as possible with small horns like klipsch

[@joe_limon]

Hey Paul. I want to send you some pictures of a neat speaker I built. What would be the best way to send them?

[@Bob-yl9pm]

Paul? What do you think of Heil's (AMT) Air Motion Transformers? I personally love the crisp (clean) vibrant highs?

[@Bob-yl9pm]

I've been told Ribbon tweeter sound as good, ;) Not to me!

[@Bob-yl9pm]

I was a teenager, couldn't afford them. LOL., BTW, Dyanco A-25's were Great (for ~ $100 a pair, in 1970's dollars)! Remember?

[@Bob-yl9pm]

en.wikipedia.org/wiki/Air_Motion_Transformer

[@Bob-yl9pm]

incredible transient response

[@RoseCare]

Dear Paul - I used have Philips FB690 speakers, two 8'' woofers with one off metal cooled tweeter in the middle. Were they based on d' Appalito design? www.canuckaudiomart.com/details/649297020-philips-fb-690-speakers/images/1314871/

[@Thomas-us4wq]

This would have been good if the drawings was visible.. :D LOL

[@salventuri2050]

Prozac can do wonders.

[@laurentzduba1298]

I tried using prozac while listening to my hi fi back in 1997, it drastically compressed the dynamic range and it made Kind of Blue sound as compressed as Abbey Road.

[@shaun9107]

subscribed

[@idtubenod]

Wrist strap it is BUT ground strap it definitely is. :)

[@InsideOfMyOwnMind]

They work this way, put it on at 8:59 And at 9:00 it clinches up on your wrist and doesn't release you until 5:30.

[@Relayer6a]

Paul, Linoleum? Showing your age, man. ;)

[@MrRednhot]

Hi Paul. A Famous Swedish speaker designer Bo Johanson Made A Speaker called RAUNA YMER He Made it Whit 2 woffer´s and 1 tweeter in the Middle Try Google Rauna Ymer BTW I Love Your Videos :-)

[@myronhelton4441]

D'appalito makes no sense, except. Say a tweeter is on top of two 6 inch woofers, with the bottom woofer crossed over lower than the top woofer. With the two woofers having their own separate, sealed, & ported cabinet chambers. With the bottom cabinet chamber, larger than the top cabinet chamber for more bass. This is a 2 & a halfway design. PSB has a speaker like this.

[@gerritgovaerts8443]

What is not mentionned at all are the very strict requirements on max distance between the centers of the midranges as a function of the Xover frequency to the tweeter . No commercial MTM speaker I know off meets this requirement , not even close . A typical MTM design with two 7 inch midrange/woofers crossed at 2Khz to a 1 inch tweeter is very far from being true to the d'Appolito design criteria.

[@TimpBizkit]

Do you need that quarter wavelength spacing? (Which typically results in a much lower crossover than the tweeter will comfortably handle e.g. 400 Hz)

[@SJMessinwithBoats]

Nice explain, So I see this design has more than 2 drivers that make midrange?. That personally is against my list. In my thinking, anything above 200hz should only have one driver in their box. Oops!

[@SJMessinwithBoats]

per pass

[@SJMessinwithBoats]

Thanks, I think I can just barely grasp the wavelength tech. I personally tried the two mids with a tweeter several years ago. They were in the horizontal position, and that was bad for me. I peeked at the speaker that Paul refers to, and its 6 feet tall! I see now that the trend in typical speakers is two way book shelf or this narrow multi driver set up. I do live on the outskirts of hi-fi. Admittedly, I haven't seen the inside of hifi mag in decades. They are hard on me like sail magazine. Ultra tech and ultra pricey. I can sit on my formula for all the things I desire , and revisit 10 years from now and it will be the same song. If Paul's shop system is the standard, then he's got a couple too many tweeters there. I am trying to go minimal and have it acceptable in size for the living room. I am sure it will come down to a "show me" someday. I'm sure it will be flawed in some way. It just wont have more than one driver for each in the mids and uppers.

[@janinapalmer8368]

I've never heard of such a strange thing to do .... The D'Appolito principle is based on a single source of HF not two separated tweeters .. god only knows what lobing and weird phase shifts will occur ... It pronounced DAPPOLEETO NOT DEE -APPOLITO btw ...

[@khoi83]

sorry, but it's d'AppOlito because his name is Joseph d'Appolito.

[@khoi83]

kzbin.info/www/bejne/e2bUc59jp5Wtl9E

[@gerritgovaerts8443]

It's called d'Appolito , NOT d'Appalito

[@paulp.4970]

True, but not SO important.

[@PeterPaoliello]

Gerrit Govaerts you must be fun at parties

[@zaldam]

It is a name, please don't butcher names

[@MichelLinschoten]

It is important especially if you tote yourself an expert...

[@scottlowell493]

Ok Mr, Mc GOWN.

[@nonyadamnbusiness9887]

Get a white board.

[@bobsmith8368]

My budget can't handle your equipment, if I dropped by your place, I know I would end up destroying my finances!

[@Yooyangs]

ESDS

[@mauriziob5944]

white

[@zaldam]

appalling ...

[@_Chev_Chelios]

I doubt Paul understands, much less can explain a D’Appolito array since he can’t spell it or pronounce it.

[@MichelLinschoten]

The more I see from Paul, the more I realize he is just the face of PS Audio. The pure blant bull crap he spews in some of his videos. When was the last time you made and designed something yourself. I bet mid 80ts?!

[@musicman8270]

Anytime you can get knowledge from an engineer its a gift, I disagree with some of what he says, but he still has forgotten more than I will ever know, not to mention he's a great speaker, very personable and likableWhen you can listen to a system like he has at PS anytime you want then you will be able to gripe.

[@grump5354]

Ah I'm getting old. Back in the 70s Advent, or an Advent dealer, did what this person from Australia is asking about. It had 2 Advent's on each channel with the second inverted and placed on top of the first. This system was reviewed in The Absolute Sound and reported to sound markedly better than a single pair of Advents. Google "the double Advent system" and you should find the review.