Can Objective Loudspeaker Measurements Predict Subjective Preferences?

[Edgar Betancourt]

No, you were. I really don't have time to waste quoting you to yourself. If you are unable to understand the conceptual differences between the methods and why they will have drastically different results or are too proud to acknowledge it, I can't help you any further.

As most people that simply want to argue you are lazy so thus I willquote myself to demostrate your rambling useless trolling
Qoute "eir methodology was anechoic chamber with on and off axis curves. The Harman method is a modern refinement of that". See its exactly what Ive said from the beginning. Ergo you are full of crap!

 

[colofan]

The Industry standard for compression testing in consumer audio is actually CEA-2034a. Various other standards exist and are in use in the pro audio industry with the primary difference being around the test stimulus used.

We will be publishing something on all of this in the coming months. I'd love to do compression testing on all speakers that come for review but there are potential risks of harm and we don't feel comfortable asking manufacturers to allow us to do that. It also brings new demands on our testing that may not be feasable. Things like sufficiently large and powerful amplifiers and an ability to play annoying tones at really loud levels for extended periods of time outside. My neighbors are likely already at their limits. I can't get far enough out into a field to totally address this problem. Still you never know, we might start doing this on some products.

I completely concur for CEA-2034a being the consumer level standard just stating a of foundation work has and still is done be AES.

Compression testing doesn't have to be destructive though. Using an optical displacement laser you can see this happening in real time with having to be concerned with any room environment getting in the way. FFT on the output can show many breakup modes and also distortion products before damage. If more speakers gave you a AES 400ms rating would be a good guide on where a driver can operate at. Though this is focused on Pro systems where headroom in a particular room is really important for live music reproduction.

 

[Speedskater]

what is 'Compression testing' with regards to loudspeakers?
or is that a repeated typo?

Compression testing is an automobile engine test.

 

[shadyJ]

what is 'Compression testing' with regards to loudspeakers?
or is that a repeated typo?

Compression testing is an automobile engine test.

Compression testing is testing to see how loud a speaker will get before some part of the frequency band just stops getting louder or when gross distortion starts creeping up.

 

[colofan]

Every mechanical system has a region that goes into non-linear mode in two ways. The suspension is stretched beyond where the mechanical properties of the material can "spring" back in a linear fashion. Or the magnet motor with the moving membrane moves out of the linear electro-magnetic region. Typically 70% field strength is given as the limit for the speakers "motor".

The end result is putting more power into a driver that does not respond in increased SPL linearlity.

Company that has instruments for this as an example is Klippel in germany.