Is it better to run the preamp level higher and the sub gain lower or vice versa?

[Bassman2]

Which could be expected to give better sub performance....preamp level higher and powered sub amp lower.... or pre level lower and the amp in the sub doing more work? Hmmmmmm...

 

[MDS]

The volume control on the sub is going to have a much greater range than the subwoofer level in the receiver. It is usually best to have the sub level in the receiver greater than or equal to zero because if the level is too low the 'auto-on' feature of the sub may not work too well.

So you start with the sub level in the receiver at zero and start adjusting the sub volume to get the desired SPL. If you can't reach the target SPL, you bump up the receiver level and go again. You don't want either level to approach the max so you have to find the right combination of the two.

Unless the sub isn't powerful enough for your room, you rarely ever have to go beyond 1/2 way up on the sub.

 

[mike c]

my receiver sub level is always at 0db unless the sub is still too loud, if it is, I go to the negative but I avoid the positive receiver sub levels.

 

[Davemcc]

SVS recommends in their owner's manual after setting the sub output to 1/4 to 1/3, "Set the receiver's subwoofer output signal no higher than -5 dB initially." Then, "We recommend you turn down the reciever's subwoofer output level before you significantly lower your sub's volume/gain control. This helps keep distortion sent to your SVS to a minimum. You should not be set (sic) this control much lower than -5 dB however, since some adjustment may be needed to fine tune levels later. If your subwoofer reading is still too high, then turn down the sub's amp volume a little with each run."

 

[Bassman2]

Well the common denominator in the responses seems to be not to tax the subs amp too much by providing a healthy but not excessive preamp voltage to it. That way , it would seem, the sub amp has plenty of room left before it clips. Yes? Oddly enough that's exactly what I wound up doing when I set it up.

 

[Nuglets]

Well the common denominator in the responses seems to be not to tax the subs amp too much by providing a healthy but not excessive preamp voltage to it. That way , it would seem, the sub amp has plenty of room left before it clips. Yes? Oddly enough that's exactly what I wound up doing when I set it up.

The amplifier is still doing just as much work in either scenario. A higher pre-out voltage will not decrease the amount the amplifier has to work in any way and it will still clip at exactly the same volume.

As far as that statement about SVS recommending -5dB on the receiver's sub channel I don't think that is an issue with any properly designed receiver...There is no reason that the pre-out should clip or distort even when turned up past 0dB with the volume at high levels.

I think ideally 0dB on the receiver should be where you set it for movie reference level and adjust +/- a few dB to your preference when you change the source material. If your subs auto-on feature is not working correctly then you will have to set the level a bit higher on the receiver because either the pre-out voltage is lower than normal or the input requires more voltage than normal to trigger the auto-on.

 

[tonay]

From what I've read around the web etc...you want to stay in that +/- 5 on the receiver settings and use the sub gain controls to get in that range.

I'm not knowledgable on this but it seems to me the less you make the receiver adjust the better.

 

[Nuglets]

I'm not knowledgable on this but it seems to me the less you make the receiver adjust the better.

Not necessarily...the main reason for buying a receiver is to get the adjustments and features that you like. It's also much easier and more practical to just press a button on the remote and turn the sub up a few dB's than it is to have physically turn the knob on the back of the subwoofer. I personally don't use the EQ in my receiver much but it doesn't hurt to play around with an EQ or tone controls.

As long as the subs auto-on feature is working properly and you are able to get the desired SPL level(within the subwoofer's limitations of course) I think your best bet is to set the sub-level in the receiver to 0dB and make necessary adjustments as needed. If your sub isn't as loud as you think it should be and you are approaching the maximum gain on the sub then turn the sub level up on the receiver.