Best Loudspeakers for Rich Timbre?

@invictus005
I stand corrected- I was not aware that anyone had combined a class A and class D amp in the same circuit.

What you may not know is that we have done some class D work as well and have our own patents.

seems like you’re claiming no amplifier designer knows how to design an amp that will be just as good driving a 4 ohm load as driving an 8 ohm load. Am I correct? I don’t think you speak for all amplifier designers out there.

@dracule1
Yes, you are correct and I think you will find that any designers will admit to the same. Keep in mind though that this is not the same as saying that the X brand amp can or can't double power as impedance is halved.

I know you don't believe me; just look at the specs of any amplifier.

I believe most will disagree with you including myself. Bass grip is not the end all for an amplifier design.

Yes- in fact its not really a 'thing' at all. There really aren't any speakers that need more than a 20:1 damping factor, and most need something a bit less for optimal bass response.

Yes, all are at least partially class D. Class D has an absolute iron grip on bass response. And the above three have gotten so state of the art, that they even surpass the best analog designs. Anyone looking for amazing timbre, look at the above first.

There really isn't anything that is partially class D. It either is or it isn't. IME most class D amps fall apart in the bass until you get to recent examples made in the last few years.

Your argument that apogee would sound better if it were higher impedance is false based on imperial evidence.  Case in point the 1 ohm Schintilla sounded better than 4 ohm Schintilla, as long as you could find an amp that could drive 1 ohm load.  

@dracule1
I think you missed my point. As far as I know, there isn't any empirical evidence, because there is no way to make a four ohm speaker magically 8 ohms or more because the design would be different.
I'm looking at this from the point of view of the amplifier, which will sound the best if its distortion is kept to a minimum, and that is done only when the amp drives a higher impedance.
The idea is to avoid the brightness and harshness which is how the ear interprets small amounts of higher ordered harmonic distortion, as well as increased intermodulation distortion. The only way to do that is to have the amp drive a higher impedance. You can't get rid of it by turning down the treble since the brightness is caused by distortion, not frequency response. You can turn down the treble and brightness is still there.

You and I are both not convinced by our rooms at RMAF and the like. We've only gotten sound I really liked at a show twice- once was in Munich, and the other was at THE Show many years ago in Las Vegas.

I hope my DeVore O/93’s are on your list of the speakers that meet your preferred characteristics.

@fsonicsmith

I like them a lot; every time I've heard them they were very convincing. They are a good example of what happens when a speaker is easier to drive.

@dracule1I think you might be glossing over my comments here.
All amps, tube, solid state and class D, make more distortion driving lower impedances. Its a simple physical fact- you can see it in the specs.
Its also a fact that the human ear converts distortion into tonality, and a further fact that the distortion generated by all amps into lower impedances tends to be higher ordered harmonics and increased IMD. Both are extremely audible to the human ear and contribute to harshness and brightness.
I agree that the Apogee and Magnapans are excellent speakers (and if you have enough power, work quite well with tubes). But what you may not be considering is that if these speakers were higher impedance, they would sound smoother and more detailed- in fact, more real, regardless of the amplifier employed.

If you have a 4 ohm speaker, and a solid state amp, you may have a 3 db argument for 4 ohms if sound pressure is your goal.

But if **sound quality** is your goal than your amplifier investment dollar is best served by a loudspeaker of higher impedance.

Now one problem with a speaker that is simultaneously low impedance and also low efficiency is that you need a lot of power to make it work. There really aren't many amps out there that make a lot of power while also sounding like music. It puts them at a disadvantage. Its really a Bad Idea to make any amp work hard for its living- the result is less musical.

Regarding your comments about the Classic Audio Loudspeakers (which are 16 ohms), as you already know the impedance is not what makes them sound a certain way. Some people look at them and see a horn, and don't take the speaker seriously no matter how it sounds.

In my case, I recorded an LP (Canto General) and because I recorded it, I was actually at the recording sessions :) 

I know what that LP is supposed to sound like- I was there. It makes an excellent reference for me.

The Classic Audio Loudspeakers do more of what is needed to sound like that than any other speaker I've heard, but by no means have I heard all speakers. While many speakers can make the soundstage, often the bass is missing or colored, or the highs don't sound like O'Shaughnessy Hall and so on. My choice to use the Classic Audio Loudspeaker is purely based on them providing the most neutral presentation of that reference. I have high regard for Sound Labs, and would have bought a set if I could have figured out how to make them work in my room (I've also considered Magnaplanars as many of our customers own them, but couldn't make them work in my room either).

Please pardon me for walking my talk. I'm not going to tell you something that I don't believe myself. If you feel that I should not be participating on this thread, please say so.

As an amplifier designer I can tell you that many speaker designers have very little grasp on the relationship that has to exist between the amp and speaker.
If the speaker is harder to drive, the amp makes more distortion. In particular if the amp is solid state, the distortion will be mostly higher ordered harmonics to which the ear is keenly sensitive as it uses those harmonics to sense sound pressure.
So to prevent this, the speaker should be higher impedance and no weird phase angles. This pretty well precludes four ohm speakers unless they are really efficient! Why four ohms is a Bad Choice if your goal is high end state-of-the-art reproduction is a topic worthy of its own thread!

IOW distortion plays an enormous role, because our ear/brain system simply converts distortion into some form of tonality. So if you want a rich timbre, your best approach will be to obtain a speaker that is easily driven by a tube amplifier, since tube amps make less of the higher ordered harmonics, and thus are smoother. At the very least, a higher impedance loudspeaker means that a solid state amp will make less distortion, and so will sound smoother and more detailed. When 'smooth' and 'detailed' occur at the same time, that's when you are making progress.

I do not think this means any sacrifice need be made to detail and neutrality on the part of the loudspeaker! An excellent example of this sort of craft are the loudspeakers made by Duke (audiokinesis) which are easier to drive due to moderate efficiencies and higher impedances. I can name quite a few others but in a nutshell, the actual tech isn't nearly as important (so long as the designer knows what he is doing) as is the simple drive-ability of the finished loudspeaker.