Pair Deviation List (S&R)

[pozz]

Round 2 is pair deviation as measured in active loudspeakers by Sound & Recording: https://docs.google.com/spreadsheets/d/13PBC7_f7wM1rkXZ-fLqyR-zuFNSYa2BToDsxQJnxKUI/edit?usp=sharing

Main issues here are the low sample size (two random speakers, only a few models per brand), though you could call that the "luck of the draw" sample size and in that sense fair, and lack of FR information. Also unclear how repeatable the procedure is, seeing the super tight tolerances some brands achieve.

Brand/Model:


Brand Average:


Stats:

In terms of interpretation, it's all spectrum dependent. As is often said here, level matching is important down to 0.1dB. However, that's in the electrical domain, where you can reasonably expect to have that kind of accuracy between channels. Acoustically, I don't know that we can hope for that level of similarity with speakers, especially considering reverb and positioning in-room, and the spectral crosstalk cancellations caused by stereo sound.

So no firm threshold. It's surprising how well some companies do, but unsurprising that the favorites around here do really well (~0.5dB tolerances).

 

[restorer-john]

So, a worst case deviation, average or what? Or weighted across the entire 100Hz-10kHz?

In and around Xover points from sample to sample, these deviations would be expected, especially with active, but passive Xovers to the drivers.

Where there are two/three internal amplifiers, DSP and matched drivers, the differences would be extremely minor.

 

[pozz]

So, a worst case deviation, average or what? Or weighted across the entire 100Hz-1kHz?

Maximum difference within the 100Hz to 10kHz range.

What differences there are obviously aren't severe even in the worst case, but few manufacturers (just Neumann?) post the numbers to make their case concrete. How much effort put into matching and so on, and for what result.

 

[thewas]

Wow, didn't expect PMC to do so bad even at this category since they seem to be using at least not low cost drivers.

 

[Koeitje]

0.3dB as the maximum difference is insanely impressive.

 

[pozz]

0.3dB as the maximum difference is insanely impressive.

Def. I find it shocking that Neumann gets 0.2dB deviation for the KH420, a 3-way bass reflex design.

 

[Stephen]

Neumann: "Deutsch qualität"...

 

[Vintage57]

Proud owner of the Neumann KH420