TD15M, donate for Klippel testing?

**Dennis H** · 22 January 2009, 20:41 Thursday

I'd rather see some distortion measurements (for any driver). Klippel or Dumax is kind of an indirect measurement of what we really care about and what we can hear -- "the Bl, Le, Kms, whatever, curve is doing this so we'd expect that kind of distortion." Just measure the dang distortion and be done with it. Who cares what causes it?

**thadman** · 23 January 2009, 00:23 Friday

Originally posted by Dennis H

I'd rather see some distortion measurements (for any driver). Klippel or Dumax is kind of an indirect measurement of what we really care about and what we can hear -- "the Bl, Le, Kms, whatever, curve is doing this so we'd expect that kind of distortion." Just measure the dang distortion and be done with it. Who cares what causes it?

The Klippel measurements will give you a more defined picture of its performance. Since we're measuring the mechanisms that cause the distortion we're able to discern its capabilities at varying amplitude levels.

**Dennis H** · 23 January 2009, 01:38 Friday

We'll just have to agree to disagree there. Personally, I could care diddly about "mechanisms"; all I care about is performance, which is easily measured. Can you look at a Klippel report and tell me the % 5th harmonic at 700Hz at 100dB/1m?..... Nah, I didn't think so.

Klippel and Dumax are useful for people who design drivers so they can see where they might make improvements. They're somewhat useful for people who use the drivers if they don't have anything else but distortion sweeps at different power levels are WAY more useful for people actually using the drivers.

**ThomasW** · 23 January 2009, 15:04 Friday

Enough said.....

TD15M, does anybody have one willing to donate for...

http://www.avsforum.com/avs-vb/showthread.php?p=15631832#post15631832

**tktran** · 23 January 2009, 22:06 Friday

John E. Janowitz
Acoustic Elegance, LLC said:

Finally we get to the accurate comparison to other drivers. All the Klippel data in the world doesn't mean anything if you have nothing to compare to. Where is the Klippel data for the TAD1601, JBL2226, Altec/great plains 15's, EV, 18sound, B&C, etc that people have been replacing with the TD15M's? It was for this same reason that I chose not to have Zaph do the testing on the TD12. There were admitted limitations and issues with the method and there had been a total of 2 other 12" drivers he had ever tested, neither of which I had ever heard another person compare our drivers to.

Hmmm.

If no-one else has compared the Dayton Reference RSS315FH & Audio Technology 12" Flex Unit (SK300) to the AE TD12 driver, then isn't that a reason to do so?

Yes one could argue that they are different drivers (eg. high sensitivity woofer vs 2 medium sensitivity sub/woofers), but then the comparison is even more invaluable.

I smell fear...

**---k---** · 23 January 2009, 22:37 Friday

Thomas was implying that this thread should end.

**Rick Craig** · 24 January 2009, 00:00 Saturday

Klippel testing can be done for $125-$250 so it's not that expensive for a manufacturer if they don't have the resources to purchase the analyzer.

I subscribe to Voice Coil magazine and they have Klippel tests for drivers that they review. As already mentioned here it's probably more useful in driver design than helping a DIY person compare woofers; however, it can show if motor and / or suspension has certain advantages. One aspect I really like is that it will show if a driver is suspension and / or motor-limited in terms of excursion. Simply going by x-max is not enough and with some manufacturers their x-max rating may be totally useless.

There are some situations where the Klippel cannot provide data but for most of the important mechanical, electrical, and thermal parameters it's the industry standard. If the AE motors have a performance advantage then it would be a good advertising tool to be able to boast of good Klippel numbers. On the other hand, you cannot simply dismiss a company for not having any Klippel tests to show. I have used a number of drivers that perform very well but have never seen any Klippel tests (though I suspect that they would fare pretty good if tested).

On thing I would like to see is how the Klippel numbers and Linkwitz distortion tests compare for specific drivers. To my knowledge there isn't anyone investigating the two methods together.