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Descent with Summit's ?

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Russb

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My Summit's are know broke in and they sound great. I also still have one Descent sub in the system. I am not sure if I realy need this sub in the system. I play music with out the sub , and with the sub. I can't seem to tell the difference. The Summit's sound that good. The Descent is located dead center between the Summit's. This may sound weird , but the bass seems stronger without the sub then with it. I just can't see a big difference. Can anyone out ther give me some advice. I tested the sub by itself and it is working like it should be.

Thanks

Russ
 

gstring

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Do you have a sound level meter? That would be the easiest way to ensure that the levels are properly calibrated. Also, the most ideal spot to radiate bass energy is almost always corner placement; however, that might not be an option.
 

Craig

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This may sound weird , but the bass seems stronger without the sub then with it.
Not wierd at all. More than likely your sub is out of phase with the speakers and therefore the sub is canceling some of the low frequency sounds from your speakers. In other words its working against your speakers instead of complimenting them.

First verify that all the positive and negative connections from your amp to speakers and amp or preamp to sub are consistent. Once your sure they're good then adjust the phase knobs on your sub until you hear an increase in bass along with the speakers instead of a reduction. A radio shack meter helps for adjusting phase in addition to other settings. If your sub is out of phase with your speakers or if your speakers are out of phase with each other then you will have a slightly reduced SPL as a result.
 

Russb

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Thank You everbody for your help.
I did happan to start adjusting the phase knob on the Descent I didn't know what else to do. When I put it to 270 it seemed to have increased the bass and blended in better with my Summit's. I was able to turn the volume down and still get good response. Still not sure if I should sell the Descent and just run with the Summit's.

I don't understand what this phase control is doing can some one explain this to me.

Thank You
Russ
 

amey01

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Russb said:
Thank You everbody for your help.
I did happan to start adjusting the phase knob on the Descent I didn't know what else to do. When I put it to 270 it seemed to have increased the bass and blended in better with my Summit's. I was able to turn the volume down and still get good response. Still not sure if I should sell the Descent and just run with the Summit's.

I don't understand what this phase control is doing can some one explain this to me.

Thank You
Russ
Phase is to do with the fact that equal and opposite waves cancel each other out - the net effect being nothing (or silence). If your subwoofer is out of phase with your speakers it means that it is producing sound waves of equal (obviously) but opposite amplitude, meaning they cancel each other out.

Obviously you can rectify this by positioning the subwoofer correctly, but because bass has such a large wavelength, you would have to make some pretty drastic changes in position - that is why most subwoofers include a phase switch to switch phase instantly.

As Craig said, this is most likely your problem. The Descent is a great sub, but may be unnecessary with your Summits given your tastes and their excellent performance. I'd certainly be keeping it if you plan to listen to movies through your system, but if it is strictly music only then trust your ears - it may not be necessary.
 

Craig

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If your sub is out of phase with your speakers then what is happening is that your sub's woofer is pulling in when your speaker's woofer is pushing out (and vise-versa). One is moving in the opposite direction of the other (out-of-phase). The out-of-phase speaker is literally absorbing the sound produced from the other speaker.

Noise cancelation ambient sound and then drives a speaker out-of-phase with the sound thus canceling out the sound waves.
 
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