Quote:
Originally Posted by manonfire /t/1372020/power-sound-audio-discussion-thread/3810#post_23480229
Just curious does one way yield better results than the other. I have my xv15s corner loaded on each side of wall they are both about 11ft from lp. I calibrate all speakers and subs to 80db with spl meter and avr sub trim 0 and volume at 15 SMS. For most part the subs gains are pretty much in same position. I get about 6db room gain. But i take it I level matched my subs.
Yes, what you're doing is level-matching... and level-matching *can* be the equivalent of gain-matching... if the subs are relatively equidistant to the listening/measuring position, and they similarly load the room modes. If the gain settings on the sub are "pretty much in the same position" then you've both level-matched and gain-matched.
Gain-matching can be a better solution if the gains are set significantly differently with level-matching. When that happens, the subs are no longer "identical" subs, they're set to different gain structures and the higher set sub will have less headroom than the lower set sub. The higher set sub will compress and distort before the lower set sub and it will set the overall "limits" for the subwoofer system. If you have identical subs and you want to ensure that you can use the maximum capability of all the subs, gain-matching is the only way to do that.
Quote:
Originally Posted by BeeMan458 /t/1372020/power-sound-audio-discussion-thread/3810#post_23480341
The standard is to set the gain at 1m but doing so allows for room based acoustical influence.
Measuring at 1 meter is the "standard" for measuring speaker sensitivity and frequency response in an anechoic environment. However, that's not the standard for measuring subwoofers. The CEA2010 standard for measuring subwoofers is to measure them at 1 meter OUTDOORS, GROUND PLANE where no room effects are possible. If they are measured indoors, they are to be corrected for the room's modal response with an empirically derived Room Correction Factor, (RCF):
http://personal.inet.fi/private/zipman/starobin_CEA2010.pdf If you are not applying the RCF, your 1 meter measurements are not being performed according to the "standard." You may discount the importance of this for yourself, and that's fine, but when giving advice to others, you should not portray the "standard" as something it is not.
Measuring the sub in the middle of the room at 1" from the driver is as close as one can get to an outdoor groundplane measurement, (in terms of removing the room from the measured response), as is possible without taking the sub outdoors. When gain-matching, it is absolutely essential to remove the room's sonic signature from the measurement.
Quote:
Originally Posted by BeeMan458 /t/1372020/power-sound-audio-discussion-thread/3810#post_23480341
Personally, not having done a study, I have no idea how much difference setting measurements at 1m, 1ft or 1in makes when it comes to matching subwoofer output.
And there's the rub... you're telling people it's OK to do it your way, when you really have "no idea" if it's OK. It's perfectly fine for you to do this in your own system. However, when telling other people how to do it, we should only ever give the *correct* advice, even if that advice seems overly OCD or "purist."
Quote:
Originally Posted by BeeMan458 /t/1372020/power-sound-audio-discussion-thread/3810#post_23480341
I set the gain at a measured thirty-nine inches and then run EQ efforts and use REW as the final arbiter of our systems parametric settings. Not being a purist, in my opinion, setting a system flat in this fashion will get most of us where we want to go......in our seat, lights out, with a way cool movie track in progress.
Unfortunately, you're right... that's probably good enough for "most of us."
Craig