Stereophile spec measurement baffling(pun?)

Room EQ Wizard.  Software for acoustic measurements. 

What is REW?

An SPL meter doesn't sound like a bad thing to have in the house.

REW is better.

I had forgotten until yoyoyaya mentioned, bass test tones. The last time I tweeked my Paradigm subwoofer/monitor system I used tones for the setup. An SPL meter doesn't sound like a bad thing to have in the house.

At best it can tell you how much air the speaker can move. Audiophiles rely on this spec way too much IMHO, especially when deciding whether or not to add a subwoofer and how to configure one. The room makes liars out of all of the anechoic/quasi-anechoic bass measurements.

IMHO, measuring dynamic compression is of more value for most of us, and the one publication that used to do it (SoundStage) I believe stopped publishing these measurements.

There’s no substitute for listening, and measuring in the room.

The anechoic -6dB point is useful to know when considering what LF the speaker will offer in your room when the effect of room gain is added.  Sometimes, companies will offer low end response in a "typical" room but without stating the room dimensions.  

See: https://www.svsound.com/blogs/subwoofer-setup-and-tuning/what-is-subwoofer-room-gain?

@OP, the 805 matrix has a bit of a bump between 100 and 120Hz and falls off fairly rapidly below 80Hz so you probably want to cross it over somewhere around or below 80Hz. Ideally, use a set of bass test tones and an spl meter to check the frequency response of the speakers in your room first though, as the above is only a guide based on the room averaged response that Stereophile measured.

Thanks ditusa. This looks like a great read.

Maybe this will help see here

Mike

I'm trying to get an idea of where to begin the setup of a B&W ASW800 with a pair of B&W 805 matrices.

Agreed. Stereophile is respected for its balance of objectivity and subjectivity, with extensive listening tests backed by proper measurements. ASR and AS, on the other hand, represent two extreme ends of the spectrum, though they shouldn't be discredited for what they contribute. Audiophiles simply need to digest the information more intelligently.

At least they still take measurements unlike Absolute Sound. I don't think measurements are the final word in a devices sound and hate ASR. Power out measurements and speaker sensitivity are both important to me.

The industrial standard should have always been -3dB or -1.5dB. The perceived sound level drops 19% at -3dB instead of 34% at -6dB. More restricted tolerance is -1.5dB, where the perceived sound level only drops 10%, making it more appropriate threshold for defining roll-off tolerance in anechoic room setting.

Usually to help define woofer roll-off.