Axiom Home Page Forums General Discussion Home Theater Missing High Bass?

It would make the driver on the sub 180 degrees out of phase of the M22 drivers. Try it it won't hurt anything.

Higher-end subs usually have a switch that disables the sub's internal crossover network completely - it's usually labeled 'BYPASS'. It sounds like your receiver is doing the crossovers, and that's the correct way to do it. Your sub then should not perform any crossover actions itself. This is when you would want to flip the BYPASS switch, or if you don't have one, set the crossover dial on the sub to as high a frequency as it will go to seperate the crossovers as far as possible.

The problem occurs if both your receiver and your sub are set to similar crossover frequencies, as you'll get overlapping crossovers that can do weird things to the sound quality, i.e. a mid-bass hole. If you can turn the subs crossover higher than 110-120, do it.

Tinkering with the phase switch probably won't help, but it won't hurt anything either. Don't be surprised if you can't hear any difference between 0 and 180.

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Pardon my newbie ignorance, but how would you bypass the crossover on the Sub.

My receiver's crossover is set at 80Hz. I had read somewhere to put the sub crossover a bit higher so it will be sure to pick up all of the signaal the receiver sends tto the sub. So I have the sub crossover at 110-120. Is this incorrect?

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Keep in mind that switching the phase to reverse (180 degrees out of phase -- meaning, simply, that the sound wave gets flipped upside-down) may bring the total sound more in phase, depending on the arrangement of the speakers and room interactions.

Sound perception (a.k.a. hearing) works by adding together all the sound waves that enter our ears. If one sound wave has a peak where another one has a trough, then the resulting 'wave addition' results in a quieter sound than either of the two waves alone. This page explains it pretty well, with pictures: http://hyperphysics.phy-astr.gsu.edu/hbase/sound/interf.html

I like that site, I've had it bookmarked for some time.

From Alan.

"What does the "Phase" switch on my subwoofer do? Do I set it to 0 or 180?

It synchronizes the in-and-out movement of your sub's woofer with the woofers in the rest of your system so that when the subwoofer cone is "pushing" air out, the other woofer diaphragms are also moving outward. If your subwoofer is on the same plane as your front speakers then set the subwoofer phase switch to 0. If your subwoofer is located anywhere else then try the phase switch in both positions and set it to the position that produces the strongest bass at your listening position. Given the vagaries of bass standing waves that result in all rooms, you may notice no difference at all, in which case set the switch to 0."

Thanks!

Turning the crossover on the sub up to 150Hz (that's the max) has helped a bit. It hasn't completely fixed the problem, but its enough to make it a little more tolerable until I buy an upgrade.