Why aren't coaxial speakers more popular?

[Zen Mod]

Zen Mod,

You got me! Big Iskra VoT are "spitze". I do not understand how anybody could prefer loads of direct radiators in movie theaters when couple of VoTs behind the curtain sound so much better.

bass cab of Iskra VoT was direct radiator type , even if ,generally, sort of BR-ed IB

It should be understood that the concept of Dual Concentrics date from the time when high power amps were rare beasts and loudspeakers had high efficiency, so low power was enough for relatively high SPLs. Therefore low cut off frequency and high distortions was not that much of concern.

looking at DC generations - power raised with time , exactly from need to cope with increased SPL demands
we need to blame guys from recording studios mostly

 

[ivanlukic]

I've noticed that in US designers tend to cut high, as far away from tweets Fs as possible. But in Germany, for instance, designers tend to cut low, to achieve as flat fr as possible. Although Tannoy DC is more of the second approach, it is loudspeaker that sounds remarkably clean at high SPL.

 

[Kindhornman]

Ivan,
I won't say that one method of choosing the crossover frequency it better than the other. Flat response is part of the goal obviously, but consequently it is also to keep away from a resonant peak. If you are going to cut close to the fs then you would naturally in my opinion need to use high order filters to limit the excitations at resonance, this is the tradeoff that you have to think about. Many people seem to think that you can just use a notch filter to counter this problem but if it is a natural resonance that is often just not true. A simple harmonic multiple can still cause that frequency to be excited and then things bad will start to happen. Electrical filters do not affect a natural resonance, they are not controllable by electronic means.

 

[Charles Darwin]

The power limiting factor with old Tannoys is the glue which keeps the coil on the former and the former itself.

If you get old ones reconed you'll get exactly the same vc but a kapton former and modern glue. Power goes up from 15-60W (depending on model) to about 300-350W.

Tannoy tweeters are remarkably robust. During a party mine got turned up full for about 10 minutes, that is around 400W to my Volt woofers, 250 to Tannoy cone and up to 175W to the tweeter. Didn't hear a major increase in distortion but things kept falling of my shelves and the windows rattled… a lot!
In fact going up in power the sound does not really change at all, unlike most other speakers I had dealings with. This can be disconcerting as they tend to be a fair bit louder than one thinks due to the lack of distortion.

 

[Charles Darwin]

Ivan,
I won't say that one method of choosing the crossover frequency it better than the other. Flat response is part of the goal obviously, but consequently it is also to keep away from a resonant peak. If you are going to cut close to the fs then you would naturally in my opinion need to use high order filters to limit the excitations at resonance, this is the tradeoff that you have to think about. Many people seem to think that you can just use a notch filter to counter this problem but if it is a natural resonance that is often just not true. A simple harmonic multiple can still cause that frequency to be excited and then things bad will start to happen. Electrical filters do not affect a natural resonance, they are not controllable by electronic means.

The notch filter in Tannoys passive crossover is there for two things:
Modify the 6dB roll off to a shelf and deal with a loading/FR issue somewhere around 2-3kHz which creates the horn honk.
With an active xover the notch only needs to be very mild, just under -3dB at 2.5K in my case. I would expect that to be well above resonance for a 2" compression driver (2.5" on the 10" drivers for some reason).

 

[Kindhornman]

Charles that is a lot of power into a compression driver. I hope that they have wrapped the Kapton with something to damp the sound of it, it can get loud by itself. Glad you are happy with them, I have really only heard good things about them. Tannoy has always had a good reputation in studios.

 

[Charles Darwin]

Oddly enough most people I know of who swapped their Tannoys for something else chose Quad ESLs and vice versa.
That said one chose PMCs and another got rid of his Tannoys because he scored a huge Westlake system for dirt cheap from a studio.
The only reason I am somewhat jealous of the Westlakes is that they were used by The Clash rather than the actual SQ. To my ears Westlakes sound like huge Yamaha NS10s and I truly hate those.


PS: Tannoys are the only ones I know of where the same driver has been used very successfully at home, in the studio and in large PA systems.
The PA sytem was made by Court prior to Tannoy making dedicated PA drivers. If I'm not mistaken Mr Court was the guy behind the famous Pink Floyd rig.

 

[Kindhornman]

Charles,
I have to agree with you on the Westlakes, they used off the shelf Polydax drivers for a long time and they are pretty horrible but efficient with really light paper cones and a big ceramic magnet motor. Definitely not high fidelity in the least. I have a few myself, tried to use them in the past and took them out. They have a foam surround that is very sticky and everything wants to stick to them. They will probably disintegrate over time as most foam surrounds do. If people only knew what some commercial manufacturers were using they just wouldn't believe it.

 

[multitask]

I tried the 10" and 15" Silver Iris coaxials and thought they were the worst speakers I've ever listened too.

Doubt I would ever give coaxials another shot.

oh the memories. a pair of thoes 15`s plagued me for years.. lower tweeter/upper midrange sounded so bad they almoust gave me cancer!
all the fanboys at theyr forum tried to convince me it was my electronics og music that were to blame

 

[Cal Weldon]

I share those feelings. I was told to be quiet when I voiced my objection so I let the speakers do the talking. Talk they they did.

 

[Face]

Although they're far from efficient, KEF's newer coax drivers sound really nice.

 

[sergeloc]

I am very curious about Cabasse´s designs. Has anyone heard those?

Me too interseted but that question hasn't been adressed

 

[sofaspud]

Because they carry an "automotive audio" stigma. Where they have been very popular.

 

[Pallas]

Although they're far from efficient, KEF's newer coax drivers sound really nice.

Agreed. I know you've seen them, but others may be interested in Klippel testing of the Q100 driver and the R-series midrange

Any progress with the 8" variants? (Which really aren't that much less efficient than the 8" Tannoy Duals optimized for smoothness of response, and have much larger voicecoils so can handle a fair bit more power.)

As for other concentrics, I'm listening to three of these right now,

with a pair of KEF R800ds bidirectional out-of-phase speakers (using concentric drivers substantially similar to the Q100 driver above, but with a slightly different cone and shorting rings in their motors) to my sides and Q100's high and behind me. Very happy!

Me too interseted but that question hasn't been adressed

The Cabasse drivers are, simply speaking, not very good.

 

[freddi]

,

the lowpass inductor's DCR can have a lot of influence in balance

I've had pretty good performance with some of Eminence's custom coax with 54oz, 80oz, and 109oz magnets - both hornless and with old school horn - here's an 80oz slug 12cx by Eminence with 2.5 AL coil. (my 109oz unit has a 4 inch CU coil and twice the xmax)

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[head_unit]

The biggest issue is that mounting the tweeter mid woofer usually degrades its response more than any benefit that comes from concentric mounting...Tweeters mounted on a post will have reflection issues from the woofer behind (unless a directional waveguide is used).

From many years experience in car audio, I can tell y'all this is quite true.

Still, coaxs are great for custom in-wall. I designed a model at PSB that used a waveguide on the tweeter. A little extra directivity meant virtually no reflection from the woofer behind, smooth response and a nice ability to aim the treble as desired.
PSB Speakers - CW180R In-Wall Speaker
David

Ah, looks nice. I see similar models, but did they have the same design technology incorporated?

 

[plasnu]

Every time I hear Tannoy dual concentric, I always feel their high end / transient is somewhat soft or blurry. I suppose they are suffered from vibrating waveguides, which cause doppler effect. They are nice, musical and enjoyable, though.

Geithains certainly have very attractive and distinctive sound, albeit they do look somewhat unsound. I'm quite surprised when I heard them at AES show. If they were less expensive, I would love to have them.

Altec / Urei also have very attractive sound, and no wonder why they are still very popular. They are obviously suffered from time alignment. 803's time aligned crossover claimed they solved the problem, but it was halfway, I think. Digital crossovers with proper delay / phase alignment would solve this issue completely, and I would like to try that in the future.

 

[ginetto61]

Every time I hear Tannoy dual concentric, I always feel their high end / transient is somewhat soft or blurry. I suppose they are suffered from vibrating waveguides, which cause doppler effect.

Hi and interesting ... this applies to all models/generations in your experience ?

They are nice, musical and enjoyable, though.

i agree sincerely

Geithains certainly have very attractive and distinctive sound, albeit they do look somewhat unsound. I'm quite surprised when I heard them at AES show. If they were less expensive, I would love to have them.

Did you like them ? which model in particular ? 2 o 3 ways ?

Altec / Urei also have very attractive sound, and no wonder why they are still very popular. They are obviously suffered from time alignment.
803's time aligned crossover claimed they solved the problem, but it was halfway, I think. Digital crossovers with proper delay / phase alignment would solve this issue completely, and I would like to try that in the future.

I agree also on this ... if you will ever do any experiments please disclose the results.
By the way i think that this delay thing could be overestimated
Still i am intrigued by the coaxial concept
Thanks a lot. Regards, gino

 

[plasnu]

Hi Gino,

I have only had a few chances to hear Classic Tannoys, but I always felt the transient is somewhat soft (in very nice way!, I wish I had them in my room!). Genelec claims: "However, the tweeter response depends on the woofer cone position and the joint between the woofer voice coil and the cone causes diffraction." in 8260A tech paper, so I don't think I completely misunderstand the dual concentric behavior...

I don't know the model number of Geithains that I heard. They had 38cm woofer. They did look very strange, but the sound is very very attractive to my ears, and I usually like the sound of horn speakers.

 

[plasnu]

Interestingly, more I get older, more I can enjoy the defect of the speakers.

I was searching "perfect" speakers when I was younger, but I learned there is no such a thing as the perfect speaker, and even it does exist, I probably still love old Tannoy, JBL and Altecs because of their obvious defect.