Axiom Home Page Forums General Discussion Technical Questions Two subs.

What is the best way to callibrate two subs?
Would it be one at a time or both together?
I have the callibration disc and the SPL meter.
The speakers in question would be an EP500 feeding
into a Polk PWS450. I'm not using a Y connector, just
line out/line in.
Thanks'
Ken.

That was a TERRIBLE Haiku!

Bren R.

I must have missed that day in Haiku class.

Bren, I almost had to buy a new keyboard. Since I stll had the cup to my mouth I got a backblast of coffee all over my glasses, instead.

Thanks.

If you are co-locating your subs -- putting them both next to each other -- then it's best to calibrate them together. But you should also calibrate them separately first. What I mean by that is that each should play equally loud. The ensure this, hook one up individually, send it a test tone, and measure the output with an SPL meter. Use the sub's volume dial to get it about 6dB lower than you want the final calibrated level to be. E.g. if you want your final sub level to be 85dB, set it to 79dB. Do the same for the second sub, adjusting its output to match the first, again using the sub's own volume dial

Now that both subs are playing equally loud, connect them both to your receiver and pretend they're just one sub, using only the level adjustments provided by the receiver.

Of course, you may find that the subs sound better together if the EP500 plays a little louder than the PWS450, or the other way around. Aren't variables great?

I've been playing around with placement and calibration of my 2 DIY subs... heh its an ongoing process. I've currently gotten the placement so the majority of the viewing area gets either the output of one of the subs or the combination of the two but one side of the viewing area gets a nasty cancelation of the bass to the point you can barely tell they are on. Very frustrating. I'm too poor to buy a EP500 (or HSU/SVS for that matter) so I continue down the tweaking path.

In reply to:

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What is the best way to callibrate two subs?
Would it be one at a time or both together?
I have the callibration disc and the SPL meter.
The speakers in question would be an EP500 feeding
into a Polk PWS450. I'm not using a Y connector, just
line out/line in.
Thanks'
Ken.

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Hi Ken. Personally, I would stack the two in a corner (PSW450 on top of the EP500) and set the PSW at the 12 o'clock position and the EP500 to the 9-10 o'clock position. Next, calibrate with reference disc test tones (most likely 75db). By stacking the two in the corner, you should get about a 6db boost. I did this in the past with two M&K MX350 subs (as suggested by Ken of M&K) and it's much more smooth and deeper base. Good luck, and let us know how it turns out.