Why speakers have only one tweeter

Loudspeaker lines can have many drivers depending on the speaker model but one thing they seem to have in common is a single tweeter. Why?

[@warrengday]

Celestion did some speakers in the 1990s with a ribbon tweater (1 cm wide, 1 meter long) that are breathtakingly transparent.

[@NoEgg4u]

1) To produce the proper decibels levels of various frequencies, you will want or need (depending on the speaker's design) more drivers for the lower frequencies. That is because, as the frequency drops, the more air the speaker has to push. And for bass, our ears are not sensitive enough to hear distortion from having more than one driver produce the same frequencies. For a tweeter, it can produce high decibel levels from that one, single, driver. Also, multiple smaller woofers (such as in the FR30s) are able to produce faster bass, as the trade-off of pushing less air. That "pushing less air" is compensated by having multiple woofers. So you get the benefit of faster bass, while still getting the dynamics and slam from high air flow from multiple woofers. 2) @2:22 "On our FR30s, we put a tweeter in the front, and we put a tweeter in the back, and that just gives you some more spaciousness." Note that the back tweeter produces 100% distortion, due to the time delay between it and the front tweeter. We generally think of distortion as bad, or bad sounding. But there is also very pleasing distortion (we hear it in countless songs, introduced by studio enhancements), The FR30s sound amazing, in part due to the pleasing distortion introduced by the rear firing tweeter. But it is 100% distortion. Rear firing tweeters are typically used in overly damped rooms, or to compensate for a speaker design flaw. I do not know why the FR30s, at their design level and cost level, would need rear firing tweeters, when most rooms have too much echo. Few rooms are overly damp. Vandersteen's flagship Model Seven speakers have a rear firing tweeter that is off by default. Vandersteen's manual reads that you should turn it on for an overly damped room, and that it is 100% distortion, due to being time misaligned (the sound from the rear tweeter reaches your ears after the sound from the front tweeter). But it does sound very pleasing. I wonder what the FR30s sound like with the rear firing tweeter defeated?

[@davidstevens7809]

So ur saying its a diff channel..matrix?

[@josephharrell5724]

Wow! Paul I watched the whole video and you lost me on this one. BTW, I love these videos. You are right in that it has every thing to due with physical wave length. When I was in engineering school I took an elective called the science of hi-fidelity which was taught by the physics department. ( I loved physics) In that class we put 2 tweeters close to each other and played a 10kHz tone from a tone generator through them. The professor had us walk around the auditorium and you could hear the tone peak in one location and drop to almost silent just a few feet away. This was because the waves would add and subtract from each other. Ideally you want the tone equal no matter where you stand. The reason tweeters benefit from being very small is dispersion. The sound will radiate out in all directions instead of beam forming in a specific direction which is the physics behind a dome tweeter design. This is preferable in a small room environment but when you get to large venues you need to beam the sound and radial horns become preferred. Remember in a small room we want flat response to the entire room as much as possible. With low frequencies the wave length is so long compared to the dimensions of the room that beaming does not happen and you can't even tell where the bass is coming from. In fact your brain just assumes that it is coming from the same source as the higher frequencies. This is the principle of the sub woofer and the basis of how a satellite with sub-woofer works. Unrelated Question: Why do you think that digital surround sound has not been more relevant to the audiophile scene? Do you think there is a future for surround sound music? It sounds amazing.

[@derrickblessel6884]

'Tekton Design has entered the chat'

[@G3rain1]

Tekton's just use one actual tweeter also. The other drivers that look like the tweeter are a cluster collectively playing the mids.

[@SantanKGhey1234]

Tekton’s array has one driver designated as a tweeter. The rest are crossed over at different frequencies to give their unique voicing…. Eliminating comb effects or phase issues. I have heard the Tekton Moabs and they sound incredible… beautiful musically and very fast/dynamic…. They perform at 4-5x the price..

[@danieljones8587]

Tekton Ulfberhts 14 dome looking tweeters, you are correct they function as mids and one functioning tweeter in the middle. You could fly a 747 through their sound stage.

[@davidstevens7809]

Well many said what i just said..haha.

[@IliyaOsnovikov]

For some reason Tekton Design founder claims that he invented the multiple tweeter array principal that Paul has described in this video. And he even got the US patent for it.

[@danieljones8587]

IRS Gama's 1-emim 2-emits 1-rear facing 1-semit I wonder where Paul got the idea of multiple tweeters on his new Aspen speakers? And, I wish I could get the same ribbon material that they and Borresen are using. Ribbons have more detail than a cone can produce. Once you've heard a ribbon you can not unhear it.

[@jim010109]

I love the way you explain things. Keep up the great feedback.

[@BB..........]

Bryston and Dynaudio are a couple brands that I've noticed use dual tweeters for some reason.

[@jeffreybrady927]

Polk Audio sda and vintage polk signature have more than 1 tweeter

[@beauport]

In the 60's and 70's Bozak made his large speakers (Concert Grand & Symphony) with 8 tweeters. The Concert Grands had two midrange drivers and four bass drivers. The Symphony had a single midrange and two bass drivers. Both in quite large cabinets. Those who have heard these recognize the quality of the sound.

[@georgemoraleswork]

Beryllium tweeters 👌🏻

[@lobstame]

Interesting. I have a pair of Heath 1348 speakers and they have three tweeters, one straight on and the other two about forty-five degrees left and right. It seems to me that works quite well in my room by creating great reflections.

[@lovejago]

LOVE YA PAUL!!!!!!

[@robertmoi8400]

Another reason is due to comb filtering. Having two sources of same high frequency will cause comb filtering due to time delay between the two tweeters and the short wavelength of high frequency. As the wavelength of sound gets larger, the distance between the drivers that can caused comb filtering increases. You can never have a perfectly flat high frequency response with multiple tweeters playing the same frequency. I guess that is one of the compromises of a line array speaker.

[@gameyspacey847]

Hi Paul, Would the positioning of the tweeter relative to the other drivers have an effect or cause some sort of interference? They always seem to be at the top of the cabinet or is that just for aesthetics?

[@theragingdolphinsmaniac4696]

My dbx speakers have 2 tweeters and a very small midrange but they are different types if speakers and are aimed in different directions on an angled cabinet.

[@warrengday]

Linn Products have been putting both a Tweater and a Super-Tweater on various speakers for about 15 years now.

[@stuartdunn2020]

Kef B&W Spendor all used tweeters with super-tweeters in the 1970s

[@paulanderson7796]

*has

[@knutarneaakra6013]

On my homemade hexagon floorstanding speakers i got 5 tweeters.2 of them firing backwards.6 mids and 6 woofers.I am using 5 and 6 inches mid and low drivers.the woofers are working in a 200 liter bass reflex case.the mid and high inside closed case. Took half a year making thise 165 cm speakers,the tuning was a nightmare. Worth it ? Think so ,quite unik and the sound quality are more like sweet honey. Got a real punch in the lower part too. 😊

[@pappachook]

Unique

[@paulanderson7796]

@@pappachookFortunately so, yes.

[@PetraKann]

The energy of a sound wave is proportional to the square of its amplitude.

[@psyphonyxaudio]

Axiom, Bryston, Polk, Tekton, .. usually .. 2 acoustic centers close together ..but father than the wave lengths produced .. will cause comb filtering. Line array aside, or Xover tricks. ( and especially not horizontally mounted ) .. the configuration has to deal with the interference patterns in either case. ( same goes for Xover from tweeter & mid/woofer in a 2 way)

[@benwu7980]

I thought there were even more tweeters in the IRS-V's. Something in a magazine years ago had Arnie talking about them. He'd been in Germany and somehow was reading a medical journal where got the idea to use a samarium cobalt alloy that was being used for something like solving eyelid drooping.

[@gtrguyinaz]

Infinity WTLC speakers did this… they were great in the 1970s…

[@gdubyadubya8961]

My Dynaudio C2 Platinums use dual tweeters at different crossover points but I don’t think its for any sort of efficiency but a design that affects ceiling and floor reflections to improve the directivity. Whatever it is, it works well. Their new models only use the one with a specific shaped cabinet that they say does the same thing. I doubt that. It will more than likely be a combination of much lower cost ( one tweeter clearly is half the cost of two ) less complex crossover ( again, lower cost ) and cosmetic appeal to their preferred market now that they are Chinese owned. Whatever, I like my old school speakers with their multiple tweeters so thats all that matters.

[@FFWrench]

How does listening to high end audio when I have hearing aids affect the quality of the listening experience? I have good hearing from low to 2 kHz and it drops down a bit and comes back to normal around 6 kHz. I can still actually hear to 13-13.5 kHz surprisingly. Military Artillery and Military aircraft caused my loss.

[@finscreenname]

The IRS V's are the reason I added tweeter satellites to my (4) Infinity RS IIIa's. The one tweeter per speaker just got lost. The satellites use RSa crossovers to feed the 4 Emits and they have their own amp. They are wired so 2 are in series and the 2+2 are wired in parallel so they come out to 4 ohms like the original Emits are. Just copied another Infinity speaker that had multiple tweeters. To use an overused cliche, they really are game changers in my system. Also one of the best things, being satellites you can put them or face them anyway you want. I've tried them sitting on the floor, facing the back wall and a 100 other ways. Found they are best facing you except slightly more toed in then the IRS IIIa's are. Just something to think about.

[@badonkadonkskidz]

M&K says hold my beer.

[@markmeridian3360]

Several speakers have or had more than 1 tweeter. The Polk L800 Legends have 2 angled tweeters. Axiom M100's have 2. McIntosh XR5 Vintage had 2 angled tweeters, Bose 901s had 9 full-range drivers, the McIntosh Xrt2.1K has 40 tweeters.

[@paulanderson7796]

What are "small frequencies"? What do you mean by that phrase?

[@ACM1000000PT]

lower frequencies are big and higher frequencies are small.

[@paulanderson7796]

@@ACM1000000PTThis might be a language interpretation thing. My fault, not yours. Are you thinking of wavelength?

[@darrellhodges3668]

Love the hoop. Is that snow?

[@connorduke4619]

Yes, apparently we are not all going to die from global warming as the billionaire green renewables subsidy recipients predicted.

[@davidstevens7809]

I agree with everything except the statements about the tweeter not needing to have voltage.(power)..of course ill add that my tweeters crossover below 2k.and they need voltage to sound their best. So far as the mutiple tweeter discussion. Yes i agree that the smaller the dia..the closer they must be.. I believe its half the dia..distance from edge to edge.. now my friend Eric Alexander uses a center tweeter with a ring of them around the center one..but its secret shading and lower xover point on the outter ones to cancel the comb filtering.. TEKTON ...

[@eddiebaby22]

Is that snow?

[@johnkonicek3642]

Surprised he did not mention the Don Keele CBT36 speakers which have 144 tweeters per pair of speakers. I own a pair and they provide a phenomenal soundstage.

[@stevecrenshaw383]

Is that a nerf basketball goal on the window next to where you were standing?

[@cengeb]

My Legacy audio Whispers have more than 1 ribbon tweeter, it has 2 ribbons, and 4 7.25" mids, 4 15" Woofers, and a passive radiator total of 11 drivers per cabinet. it moves air...it takes drivers to move air with low distortion. small woofers like PS stuff is against physics

[@jaymorin7131]

Polk SRS had 1, 2, 3 and 4 tweeter configurations.

[@timgibson3754]

I think I dug it

[@ThinkingBetter]

Wavelength is inversely proportional to the frequency of the wave. At 5kHz, your sound wave is around 2.7 inches (6.9 cm). If you have two tweeters outputting 5kHz in-phase and you move your head up such that one tweeter is 2.7/2 = 1.35 inches further away from your ears than the other tweeter, then the two sine waves will arrive 180 degrees out of phase and the result will be that the sum of the two tweeters will cancel out each other and your 5kHz will be gone. It wont just be precisely 5kHz gone at that particular position but you will experience a very uneven frequency response due to this "doubler effect" of the two sound waves either working in synergy (adding to each other) or in conflict (canceling each other out). It's therefore also called a comb effect. Lower frequencies will have longer wavelengths and therefore the doubler effect artifacts can be much less.

[@grumpysFIX]

... and wikipedia got to youtube; I think Paul's aim is to avoid technical explanations most of us don't understand or care for like yours

[@ThinkingBetter]

@@grumpysFIX Well, it’s up to you what comments you read and I’m not suggesting Paul is changing his video. Cheer up 😊

[@grumpysFIX]

@@ThinkingBetter I get why my username would be misleading 😊

[@user-od9iz9cv1w]

One of the best comments IMHO. I enjoy Paul's fireside chats, but this provides a clear explanation of one of the challenges with multiple tweeters.

[@ThinkingBetter]

@@grumpysFIX It’s ok but I know this from professionally developing audio products and I doubt your Wikipedia has any description of this concern with multiple tweeters.

[@bilguana11]

Line arrays are mostly used in stadiums and concert halls because they project further with less loss in power to the audience further back.

[@thedirtydutchman9749]

2 ears 2 tweeters

[@cuoresportivo155]

JBL ES line.. 2 tweeters, one from 3kHz (ish) to 12 kHz, and another 12kHz to 40 kHz

[@RectifiedMetals]

KISS, the simpler the better. Takes a lot of money to properly align multiple drivers. At the end of the day you have to sell the speaker, so you have to watch your design OCD, and make financial compromises as well.

[@janinapalmer8368]

This is one of my pet subjects ... 😃

[@kx8960]

Some don't, like those Infinity IRS V's you have. So, how do they avoid comb filter effect?

[@pekkatervala8476]

I believe they don't play all the same frequencies. For example, I have large 3 way speakers with 4 3" Seas dome midrange speaker elements, vertically twice more directional than horizontally. Only one dome on top plays entire 500-4000 Hz range, 2nd 500-~3000, 3rd 500-~2000 and 4th 500-~1000 Hz. This reduces floor and ceiling reflections. It takes some caps and resistors to be linear, flat response.

[@johndough8115]

@@pekkatervala8476 Curious... Why wouldnt you limit them to be like: 500-1000 , 1000-2000 , 2000-3000 , 3000-4000 ? In that way, there would be no reproduced waves to interfere with each other... and, each driver would have less work to perform... which would would result in far less potential Distortions. Interesting enough, I also came up with that idea... but I never tried it myself. Im pretty darn happy with my EPI 100v speakers. The 3D soundstage is very wide, Holographic, and Detailed (that inverted tweeter is pure Magic!). However, as good as it handles midrange too... the best Midrange drivers Ive ever heard, were some large 2 or 3 inch Dome Mids. I usually turn Mids down a bit, as I often find them to be a bit too harsh... but those mids sounded smooth as Butter. So luscious that I didnt mind them being so pronounced. Ive often considered trying to find such drivers, and add them to the EPI's, to see if they would further improve them.

[@pekkatervala8476]

@@johndough8115 That principle would need more coils on crossover. They are DIY but I couldn't design them myself. Designer is Finnish engineer Pekka Tuomela, who designed many DIY speakers for Finnish "Hifi Magazine" and a similar model for Danish Dynaudio (with 3 midrange domes) and some Finnish BBX speakers. As you know, lower frequencies have less efficiency than highs. That must have been an important reason to design such a complex and somewhat expensive configuration. I think Tekton Design has some similar principles with multiple small midrange speakers, 1-2 woofers and 1 tweeter. Some are really, really large like Tekton Moab.

[@PSA78]

Like he said it's a line aray, they will create a lobe with all the midranges that's located next to them, and it will be fine as long as they go from the floor up to the roof.

[@pekkatervala8476]

@@johndough8115 Short answer: speaker elements are less efficient on lower frequencies. This is designer Pekka Tuomela's relatively complicated and expensive solution to control reflections, directivity and linearity. Your suggestion also would need more filter coils. -If one or more of my midranges dies, I can't replace them, since they are not available and not in production after 35 years. Take a look at Tekton Desing Speakers, which have many small midrange speaker elements. Tekton Moab is a gigantic loudspeaker, with 14 ? mids and 1 tweeter.

[@onnonugteren2935]

Now please explain 'line array?' tweeters than, don''t stop so quickly! 🙂

[@manitoublack]

multiple tweeters poorly implemented = nasty phase cancelation.

[@edmaster3147]

I would indeed settle for a proper tweeter and electronics who could put out nice highs. Why make things complicated when simplicity, quality and the least possible components will do? It's so strange, in audio land more should be better while the opposite is true.

[@PooNinja]

Line arrays are soo cool. But who has the space for such things.

[@cengeb]

ya can't move air high or low without lots of drivers, if you want low distortion at realistic sound levels. where are the specs for PS speakers,

[@stimpy1226]

I enjoyed my RS-1B’s immensely until I heard Maggie 3.6 R’s.

[@bclee7933]

Tekton speakers sport large number of tweeters.

[@nobelstone9714]

But similar to Arnie's 3 tweeter array only the middle one goes all the way into the treble.

[@computerfreakch8912]

Magnepans have very large tweeters up to 1.80 long. The main reason why you don't see multiple tweeters is interference. high-school physics!

[@jedknutson8373]

tekton will dispute the title....

[@namegoeshere2903]

Sony sscs5 has entered the chat...

[@EirkenElite]

Lol sitting here looking at my xtr 2.1k damn how many are fake I got ripped off so many tweeters for no reason damn

[@cengeb]

These questions show you have some really dumb customers

[@edmaster3147]

Every customer perhaps. Good sound is not complicated.

[@Mark-lq3sb]

Customer? Who said the guy was a customer? Did the guy say he has purchased from PS Audio? With a statement like yours, you really don't come-across as a genius. The Oxford Dictionary meaning of customer- A person or organization that buys goods or services from a shop or business.

[@cengeb]

@@Mark-lq3sb he uses the Ps forum to ask questions, the answer is the service

[@Mark-lq3sb]

@@cengeb Your original post states- "These questions show you have some really dumb customers." You called the them "customers" They are not customers unless they have purchased PS Audio products, period! Your reply to my statement has nothing to do with your original post. You're lost...

[@cengeb]

@@Mark-lq3sbhow do you know the person asking is not a customer? You're confused

[@tomhoots]

"....except when they don't." Move on with your single-minded view of humanity on this planet.