Why are single drivers disliked to such an extent by most in this forum?

[Doodski]

Thank you! I have been working on this for a long time. I had demonstrated the first experimental model at a European Triode Festival in 2004, with some success. Audio friends from different countries who had heard them wanted me to build some for them. Ok, I did it. Audio artists and composers have also used them for their own purposes. I must say that I am only an amateur in this field and had no commercial interests.

Th open woodgrain on the cabinet fronts is eye capturing and gorgeous examples of what can be done with some woodgrain planning. If you put a dome tweeter in there and sell it as a 2 way you would have buyers. Easily. Offer different woodgrains and voila.

 

[SivKiv]

Yes, the sound was really good, without any tricks, linearization, elaborate boxes and the like. I got a few other audio friends to buy these and to try them out themselves. Most of them were happy. A colleague from a German forum was so enthusiastic about it that he started an audio company and now makes speakers with the F15.

The time when I myself experimented a lot with full-range speakers has actually been over for many years. But since I never had such a big 15" solo fullrange driver, and since the Lii-Audio's F15s aren't that expensive either, I wanted to try them out for once, just to see. I find the Lii-Audio product portfolio interesting today.

As I don't like having too much audio stuff sitting around the apartment anymore, I gave them away again when I convinced myself they were very good. My wife still cries for my beautiful speaker columns with the Greencones, she can't understand why I don't keep my successful pieces. But I'm the type to move on and make new things. I can't keep everything, it will grow over my head.

Oh, seeing as you've tried the F15, have you tried their F6's?

 

[Bleib]

Would love to see measurements of Ino Audio piMx, cos I just ordered these. Although it's almost impossible to buy them in America. Won't do 20khz, but I won't hear it anyway.

 

[fpitas]

I've been off practicing my two-minute hate for single drivers.

 

[mhardy6647]

I've been off practicing my two-minute hate for single drivers.

Maybe I should send yez a coupla pairs...

 

[fpitas]

Maybe I should send yez a coupla pairs...

Mount them up and focus my animus

 

[mhardy6647]

How would a dual compliance driver like the biflex differ from a whizzer? Mechanically, do they both rely on the same operating principle?

Both are approaches to "solve" (ameloriate) the same problem -- it's hard to reproduce high frequencies, with good dispersion, using a large cone/driven surface. The Altec 603B I mentioned earlier was yet another approach.

None, of course, is completely successful. Examples can sound surprisingly, good, though -- which to me is the interesting part! Engineering is all about compromise; making the most of what you've got. As such, and just like mechanical clocks or internal combustion engines (edit: or slide rules!) the best of the 'fullrange' (ahem, extended range) drivers are triumphs of design and implementation over adversity.

If we think of a 1950s radio, phono, or TV radio speaker -- which was (in the better cases) usually an 8" (200 mm) frame cone driver with a small AlNiCo magnet and a single paper cone with a dustcap, spider, and pleated paper surround -- it is amazing that they could reproduce sound as lucidly as they did (do).

 

[mhardy6647]

Mount them up and focus my animus

Feel the hate flow through you...

vs. the Sign of the Rebellion...

 

[fpitas]

The alternative to my hate, that single drivers simply have some insurmountable engineering flaws, is far more boring.

 

[computer-audiophile]

Haha, I get more pleasure from the positive comments I received from listeners of my full-range speakers. Even more so when I received them from experienced audiophiles and professionals. There is simply nothing like lived performance practice when it comes to speaker sound. There are good and bad examples in every design.

BTW: Not to forget, for example, that the Elipson Speakers I mentioned above were a studio standard for a long time at French Radio ORTF. By the way, Pierre Boulez also used such in his Acousmonium. (Also the bigger floor standers, not only these of my picture)

 

[computer-audiophile]

Both are approaches to "solve" (ameloriate) the same problem -- it's hard to reproduce high frequencies, with good dispersion, using a large cone/driven surface. The Altec 603B I mentioned earlier was yet another approach.

None, of course, is completely successful. Examples can sound surprisingly, good, though -- which to me is the interesting part! Engineering is all about compromise; making the most of what you've got. As such, and just like mechanical clocks or internal combustion engines (edit: or slide rules!) the best of the 'fullrange' (ahem, extended range) drivers are triumphs of design and implementation over adversity.

If we think of a 1950s radio, phono, or TV radio speaker -- which was (in the better cases) usually an 8" (200 mm) frame cone driver with a small AlNiCo magnet and a single paper cone with a dustcap, spider, and pleated paper surround -- it is amazing that they could reproduce sound as lucidly as they did (do).

Thank you, explained very well!

By the way, connoisseurs swear by the Alnico magnets and my own experiments with the same drivers equipped with Alnico, or ferrite magnets confirm this.

 

[computer-audiophile]

Oh, seeing as you've tried the F15, have you tried their F6's?

No, I've been through so much now.... only with 15" I still had a gap in education.
In principle, horn loudspeakers also give me a lot of pleasure. (But I don't mean backloaded horns, because they don't).

 

[fpitas]

Thank you, explained very well!

By the way, connoisseurs swear by the Alnico magnets and my own experiments with the same drivers equipped with Alnico, or ferrite magnets confirm this.

Alnico has a magnetic permeability about like air. Used as a pole piece it doesn't introduce massive inductance into the voice coil.The early ferrite drivers had no shorting rings on the steel pole piece to counter the permeability of the steel, which introduced a large varying coil inductance and distortion..

 

[computer-audiophile]

I found additional pictures of the studio monitors used by ORTF on the web.

... this is the driver which was built in. A real fullrange driver with whizzer cone.
Supravox still makes such very good drivers till today.

 

[computer-audiophile]

The early ferrite drivers had no shorting rings on the steel pole piece to counter the permeability of the steel, which introduced a large varying coil inductance and distortion..

This is true, but the Philips 9710M Alnico driver already had this internal copper cap. The later make with ferrite magnet sounded worse to my ears.
The picture is from my former collection. I only collected the Philips Alnicos for my speakers.

 

[fpitas]

This is true, But the Philips 9710M Alnico driver already had this internal copper cap. The later make with ferrite magnet sounded worse to my ears.
The picture is from my former collection. I only collected the Philips Alnicos for my speakers.

View attachment 287925

Full disclosure: TAD chose Alnico for my TD-2002 horn drivers. Maybe for tradition, although the larger TD-4003 uses neodymium.

 

[kemmler3D]

Don't have time to read all 12 pages here... but the fundamental reason that a true single driver isn't good for hifi is directivity. Even if you have infinite excursion and zero distortion so you can get arbitrary on-axis SPL at all frequencies, the sound waves propagating through the air cancel each other out in mid-air at a distance that depends on the size and shape of the cone. This is the basic cause of beaming, and it's why small tweeters can have good directivity at 15khz but 8" woofers can't.

There is also the basic fact of doppler distortion, which is also unavoidable when you have the same driver producing high and low frequencies. This is caused by the motion of the cone itself, so you can't really engineer your way out of it even with an otherwise infinitely perfect driver.

I don't think there is a real way around this until the "ideal pulsating sphere" driver hits the market in 2079.

 

[computer-audiophile]

Don't have time to read all 12 pages here...

... perfect introduction!

 

[DonH56]

Don't have time to read all 12 pages here... but the fundamental reason that a true single driver isn't good for hifi is directivity. Even if you have infinite excursion and zero distortion so you can get arbitrary on-axis SPL at all frequencies, the sound waves propagating through the air cancel each other out in mid-air at a distance that depends on the size and shape of the cone. This is the basic cause of beaming, and it's why small tweeters can have good directivity at 15khz but 8" woofers can't.

There is also the basic fact of doppler distortion, which is also unavoidable when you have the same driver producing high and low frequencies. This is caused by the motion of the cone itself, so you can't really engineer your way out of it even with an otherwise infinitely perfect driver.

I don't think there is a real way around this until the "ideal pulsating sphere" driver hits the market in 2079.

Good info, but all this has been mentioned and dismissed by the single-driver crowd (along with engineers in my case -- engineering is a swear word to many audiophiles, and physics does not apply). Despite their drawbacks, there are good single-driver systems within their limitations, using various schemes to improve directivity, and for specific applications. I'll stick with multi-driver systems myself.

There have been a few pulsating sphere designs over the years, from the plasma ball (a.k.a. ozone generator) to various plastic/rubber designs, but AFAIK none achieved commercial success. There is, or was (haven't heard about it in a few years), a MEMS design that looked interesting although scaling up for home use could be a challenge.

 

[somebodyelse]

For the former, is it the 6.5 inch by Cotswold? Or is it another set of drivers

It's been a while since I looked, but I think I went through most of the Cotswold and Tectonic datasheets. Some of them have 3rd party measurements too, like the tiny Tectonic: https://www.erinsaudiocorner.com/driveunits/tectonic-elements-tebm35c10-4-miniature-bmr-driver/

You mention specifically that this is in the case of pistonic motion, would this mean that if sound could be recreated through other forms, or a mix of multiple, would allow a potentially wider range of sound?

Line arrays were already mentioned. They have their own limitations, difficulties and tradeoffs. The various 'panel with exciter(s)' projects you'll see around are a non-pistonic example with wider dispersion than you would expect from a panel that large. NXT probably did this best, but didn't see wide success. I hear their patents are about to expire, so perhaps something more will come of it. The BMRs come under 'other forms' as a hybrid of piston at low frequencies and excited panel at high frequencies. The voice coil is shte exciter and, if I understand it correctly, carefully selected and positioned weights help control the breakup modes.