Stereo Subwoofer Connections?

[BmWr75]

Hello AKers,

I am wondering the best way to hook up two powered subs to my second preamp variable output? First preamp variable output is of course running to my power amp. The 2nd preamp output is separate L & R channels. Should I run the left channel out to the left sub input using a y-connector subwoofer cable? And the right channel out to the right sub in using an identical y-connector sub cable?

Plan to balance the volume levels of both subs to the LR main speakers using a sound meter and test signals from my CD player.

Thanks,
BmWr75

 

[whoaru99]

Shouldn't need the Y cables. Just run each pre out to one input on the sub. Seems it's generally the left channel input on the sub, but I don't think it really matters.

 

[willyrover]

On many subs with stereo inputs, NOT using a Y will decrease the level by 3db because of the way the summing network in the sub works.

If one of the inputs is clearly labeled mono "Left (mono)" then it might be fine.

This should be explained in the manual for your sub if you have it or download it.

 

[MikeCh]

You could try it the way whoaru99 states and if the level is decreased, try using a pair of Y-cables on your standard pre-out / main-in (and run the left leg of #1 Y cable to the left sub and run the right leg of #2 Y cable to the right sub) and just ignore the second set of pre-outs entirely.

 

[goanlisten]

I've been using an old Sony Receiver (STR-AV200) for years now, it has no pre-amp outputs nor a subwoofer out, fortunately my active subwoofer has both high and low impedance inputs. So I've connected the headphone output from the receiver to the (high imperdance) subwoofer in.

That works wonderfuly well for me specially since I don't use headphones and I can control the volume on all speakers with the main volume control.

But then ........ most purists would argue the headphone output isn't the cleanest in terms of noise and or distortion. My subwoofer has never complained and my ears don't seem to mind the difference if any.

You could try running one subwoofer this way........

 

[goanlisten]

I've been using an old Sony Receiver (STR-AV200) for years now, it has no pre-amp outputs nor a subwoofer out, fortunately my active subwoofer has both high and low impedance inputs. So I've connected the headphone output from the receiver to the (high imperdance) subwoofer in.

That works wonderfuly well for me specially since I don't use headphones and I can control the volume on all speakers with the main volume control.

But then ........ most purists would argue the headphone output isn't the cleanest in terms of noise and or distortion. And I'll counter with my subwoofer has never complained and my ears don't seem to mind the difference if any.

You could try running one subwoofer this way........

 

[whoaru99]

On many subs with stereo inputs, NOT using a Y will decrease the level by 3dB because of the way the summing network in the sub works.

Yes. This was a hotly-debated topic on another forum I visit.

I think using a "Y" cable at the sub input would, theoretically, provide 6dB more gain because of doubling the input voltage/signal. However, this seems to vary from sub to sub undoubtedly because of differences in the input summing network.

Personally, one of my subs increases relative output by about 4.5dB to 5dB with a "Y" vs without. I initially set up my sub using only a single input then tried a "Y" connection to see the effect. The sub's level was too much with the "Y" and I could have adjusted the level to make it right. But, it was easier to just remove the "Y" since that was how it was set up initially.

By using the "Y" only the relative level increases; the added gain does not make the sub more powerful. For example, a 200w sub is still a 200w sub regardless of using a "Y" cable or not. Because of the added gain, the sub may SEEM more powerful because it'll be louder at any given volume setting, all other things equal.

Most powered subs have level control so, regardless of using a "Y" or not, the level should be able to be blended with the mains.

I'd save the expense of buying "Y"s unless you find you would need them for a specifc reason. A few examples might be:

1. Problems with turn-on delay/automatic power-on (if your sub has this feature). Some people say this is fixed or significantly improved by using a "Y" at the input.

2. The pre-outs can't drive the sub adequately even with the sub's level control all the way up.

3. If the mfg. says to use one.