Beyond the Ariel

[Lynn Olson]

Now we're touching on coloration, a topic of endless depth. Good.

In principle, we'd like to build loudspeakers with the lowest coloration possible, so the music (which of course is filled with color) shines through. Unfortunately, the optical analogy breaks down, since unlike lenses, we cannot build loudspeakers with no audible coloration.

I've never heard a loudspeaker that doesn't have "loudspeaker" written all over it, nor have I ever heard an audio system that was indistinguishable from the real thing. Never. It always sounds like some flavor of hifi - sometime delectable, many times not.

Now, if you're lucky enough to find any system indistinguishable from the real thing, that's terrific! Your design task is then much easier - just aim in the direction that works for you, and keep on doing it.

That's not to say we shouldn't try to get coloration to the lowest perceptible level possible - that remains an excellent goal. But, considering there's always going to be a residue, what does the residue sound like? Is it disagreeable, or reasonably consonant with musical values? Are there methods to conceal it from (obvious) perception? Do the concealment methods continue to work with more extended listening, and with a wide variety of sources?

Going further, I find coloration from loudspeakers comes in two flavors: one adds colors that aren't there, such as resonances, diffraction, reflection, cabinet standing-wave modes, etc. etc. This is most audible with pink-noise, somewhat less so with large-scale symphonic and choral works, and least audible with sparse instrumentation and a lot of noodling around in the studio. If it's gross enough, though, it'll be obvious from the first moments the hifi is turned on - honky, harsh, boomy, shrill, you get the idea.

The other flavor of coloration is something we'd don't expect: it removes colors from the original performance. I've heard this often enough, and have had to contend with it in amplifiers and loudspeakers. I sometimes think of it as an overall "gray" coloration that washes out the vividness of the performances - think of a second-generation Dolby B cassette recording. Murky, opaque, dull, congested. There's no frequency-response tilting or anything obvious like that, but flip the switch and listen to the mastertape, and the degradation is obvious.

It's usual to point the finger at wretched electronics or lousy tape recordings, but loudspeakers can do this too. They can wash out the tone colors, smudge fine detail, and lose much of the expressiveness of a performance. Lots of IM distortion is the first place to look, but there can be subtler types of modulation noise that can be troublesome - noises from the spider, velocity effects in vents, and I suspect some types of damping materials have odd colorations in a subtractive sense. Weird things like this can be hard to measure, and are more easily heard by direct substitution of the driver with a different model.

The only reason I bring this up is that I've gone pretty far down the road to a low-coloration loudspeaker before, and found when I was finished that something was missing - not the coloration, but a sense of liveliness, sparkle, and excitement. It is entirely possible to build a loudspeaker with low subjective coloration by all the usual criteria (subjective and objective), but end up with a speaker that frankly doesn't play music all that well - it sounds flat, dull, and unexciting - but switch to a set of top-of-the-line headphones, and then the music comes alive again. If speakers make all of your recordings sound flat and dull, no matter how they measure, something is very wrong.

[Salas]

Originally posted by Lynn Olson
The only reason I bring this up is that I've gone pretty far down the road to a low-coloration loudspeaker before, and found when I was finished that something was missing - not the coloration, but a sense of liveliness, sparkle, and excitement. It is entirely possible to build a loudspeaker with low subjective coloration by all the usual criteria (subjective and objective), but end up with a speaker that frankly doesn't play music all that well - it sounds flat, dull, and unexciting - but switch to a set of top-of-the-line headphones, and then the music comes alive again. If speakers make all of your recordings sound flat and dull, no matter how they measure, something is very wrong.

Such loudspeakers you can meet in studio control rooms more than anywhere else.

Also, listening to good headphones is always a great sanity check. I always do that when I change something anywhere in the system, but especially when voicing a loudspeaker.

[Salas]

Originally posted by Lynn Olson
I've never heard a loudspeaker that doesn't have "loudspeaker" written all over it, nor have I ever heard an audio system that was indistinguishable from the real thing. Never. It always sounds like some flavor of hifi - sometime delectable, many times not.

We must escape mass to reach real sound. A big plasma ball modulated by signal, hanging on air in the focal point of the perfect waveguide.

Somewhere in the future maybe.

[Russell Dawkins]

I think the wires to the speaker have to be as nearly straight as possible. If there are too many bends and too many strange devices for the electrons to negotiate, very little life is left in the electricity by the time it reaches the speaker. If you were to disconnect the speaker, the energy would just sort of dribble from the ends of the wires instead of spurting as it should.

As a corollary of sorts, it is a good idea to put shorting plugs on unused inputs. This keeps the juice from leaking out the front end as well.

[Magnetar]

Originally posted by Russell Dawkins
I think the wires to the speaker have to be as nearly straight as possible. If there are too many bends and too many strange devices for the electrons to negotiate, very little life is left in the electricity by the time it reaches the speaker. If you were to disconnect the speaker, the energy would just sort of dribble from the ends of the wires instead of spurting as it should.

As a corollary of sorts, it is a good idea to put shorting plugs on unused inputs. This keeps the juice from leaking out the front end as well.

[mige0]

Originally posted by Russell Dawkins
I think the wires to the speaker have to be as nearly straight as possible. If there are too many bends and too many strange devices for the electrons to negotiate, very little life is left in the electricity by the time it reaches the speaker. If you were to disconnect the speaker, the energy would just sort of dribble from the ends of the wires instead of spurting as it should.

As a corollary of sorts, it is a good idea to put shorting plugs on unused inputs. This keeps the juice from leaking out the front end as well.

[mikey_audiogeek]

Especially with digital sources. The 0's are smooth enough to get through bent and twisted speaker wire, but the 1's tend to hang up on any kinks. Note that one end of a "1" is pointier than the other - this is why speaker cables are directional. Simple, really...

[Anglo]

Originally posted by Russell Dawkins
I think the wires to the speaker have to be as nearly straight as possible. If there are too many bends and too many strange devices for the electrons to negotiate, very little life is left in the electricity by the time it reaches the speaker. If you were to disconnect the speaker, the energy would just sort of dribble from the ends of the wires instead of spurting as it should.

As a corollary of sorts, it is a good idea to put shorting plugs on unused inputs. This keeps the juice from leaking out the front end as well.

...Batman just slammed on his brakes, stops and turns his head

[mige0]

Originally posted by Russell Dawkins
I think the wires to the speaker have to be as nearly straight as possible. If there are too many bends and too many strange devices for the electrons to negotiate, very little life is left in the electricity by the time it reaches the speaker. If you were to disconnect the speaker, the energy would just sort of dribble from the ends of the wires instead of spurting as it should.

As a corollary of sorts, it is a good idea to put shorting plugs on unused inputs. This keeps the juice from leaking out the front end as well.

avoid adding too much electron spin with big coils in passiv XO's or connect VC the other way around at least...

[agent.5]

Originally posted by mikey_audiogeek
Especially with digital sources. The 0's are smooth enough to get through bent and twisted speaker wire, but the 1's tend to hang up on any kinks. Note that one end of a "1" is pointier than the other - this is why speaker cables are directional. Simple, really...

Moreover, Data are like American race car drivers, who can only drive around in circle and will get into trouble in turns and corners. So, you need to dumb down the driving requirements and make sure that Data only need to drive straight. Otherwise, Data may be lost.