to select a driver without listen

[darkfury]

My subject about distortion and impulse response of the drivers
when I want to select a driver without listen, I think, it's very important to know those parameters

So, I found distortion responses of some drivers on Zaphaudio site

when the sound becomes louder, since most of the drivers not piston like behavior, the cone will divergence from original form and also the distortion becomes bigger than former values

My question is, how we use those distortion values on that site?
what is the reference sound level of the distortion tests on Zaphaudio site

Because those values must be related a sound level(I think?)
depending on the cone rigidity of each driver those values going to bad values separately

Will the best one be different at the maximum sound level?

any advice?

[breez]

If you read carefully the comparison pages at Zaph's the output level is mentioned. For example the 6.5" and 7" woofer comparison was made with

Amp output level was adjusted for each driver so that the fundamental was 92dB at 1/2 meter.

[darkfury]

thanks for your reply, breez
let's talk about other part of question

when we consider a sound level,
let's say 100 db @1/2 meter instead of 92 db @ 1/2 meter,
what would be the distortion responses those drivers?
Yes, we easily guess that those distortions will be higher in that case
but I want to select a drivers have the lowest distortion in those test

for the 92 db @ 1/2 meter, 18 sound driver shows one of the (maybe the most) attractive distortion results even better than hard cone drivers in those test

What about 100 db @1/2 meter case?
Will that driver be one of the best again or hard cones take the best in that case?

I think this part of question is vague and difficult to select have a min. distortion one

[Saturnus]

Don't get too hung up on distortion as a parameter for choosing drivers, it's much more important to understand how it distorts.

Remember, music is always distorted sound. Always.

[HK26147]

I'm venturing a guess in that it would have to be measured, not guess-timated.
Distortion curves usually ramp up quickly after a given point not linearly.
But a speaker can be subject to a variety of non-linear and large signal problems.

[sreten]

Hi,

Zaphs distortion measurements are comparative in level, not absolute.

What they do tell you is that driver A produces less distortion at a given
level than driver B, so is "cleaner". The fact that driver B may ultimately
play louder than A before grossly distorting does not change the fact
that A is "cleaner" at lower levels.

You can be fairly sure that as long as the drivers are within their
linear excursion limits relative distortion levels at one level will
apply at all lower levels and likely relatively at higher levels.

Testing reveals everything, but you cannot sensibly test everything.

/sreten.

[DcibeL]

Generally speaking, drivers with better motors (read: more expensive) and high sensitivity driver such as the 18Sound pro driver, will be better at high output because the driver is more linear in its' usable excursion range.

If you are looking for a driver that is very good at high output levels, a good pro driver is an excellent choice. Their high sensitivity, combined with an underhung motor and large diameter voice coils will perform much better under high power stress. The only way to really know for sure though is of course to measure.

[Saturnus]

Originally posted by DcibeL
The only way to really know for sure though is of course to measure.

You mean listen, right?

Measurements can point out reasons why a driver sounds like it does it but they cannot by themselves give you any idea about how the driver sounds.

[HK26147]

You mean listen, right?

A chemical analysis of a meal won't tell you if it tastes good.

[Saturnus]

Originally posted by HK26147

A chemical analysis of a meal won't tell you if it tastes good.

Precisely my point.