subwofer setting (1 Viewer)

[jeff cr]

hey all,

was just wondering how to set up my subwoofer. my a/v reciever has the preout that i have run to the subwoofer, now my reciever has an adjustment for the subwoofer. you can adjust the subwoofer between -6 db and +6db. does this setting control the volume to the sub? i'm not sure where to put this setting. i have tried different settings but it doesn't seem to change much. the sub has the volume control so should i just set the db on the reciever to 0 and use the volume on the sub? please enlighten me on what this receiver setting does. thanks

 

[Harry Lincoln]

Jeff, set the receiver sub level to 0db then adjust the volume to your liking using the control on the subwoofer. You can then use the receiver sub level to make small adjustments in either diretion if needed. 6db should be a quite noticeable increase in volume, not sure whats going on there, unless your running the sub at a high level and it cant go any louder. What sub and receiver do you have?

If you haven't already got an SPL meter and test DVD - get one and set all levels using that.

Harry.

 

[Rick_Brown]

Actually, I believe you should set the receiver lower, say -3 or -4 and then make all further adjustments at the subwoofer. This lessens the chance of overdriving the receiver's amplifier by instead using more of the amplifier in the subwoofer.

 

[Kevin Deacon]

Rick, no amplifiers are being used in the receiver. The pre-out for the subwoofer is just a signal with no amplification. The sub has its own amplifier. Please don't post if you are unsure what you are saying.

 

[Rick_Brown]

Kevin, with respect, please check out this thread:
http://www.hometheaterforum.com/htfo...t=sub+overload
Especially note the comments of one of the Forum's Administrators, Neil Joseph, where he states:
"Dale, I think Steve just answered that question. I have to find that thread but Steve is saying that operating at 0dB and higher on your receiver's sub out, introduces unwanted distortion on many receivers. It stands to reason then that you would want to lower your receiver's sub out so it is operating in the "-" range. As it turns out in my setup, at the sub's halfway point, my receiver is set to -6dB in order to achieve the desired level I want."
Thank you.

 

[Kevin Deacon]

Rick, with respect, There are no references in the linked thread which refer to the receivers "amplifier" controlling the output level. If this were the case a receiver would need six amps to run a 5.1 system. There is a "level control" that adjusts the amount of signal going to the pre-out. Here's a quote from the same thread:

""The level control is not actually the best name for it, as it is actually a GAIN control. The amplifier (in the sub) requires a certain amount of voltage from the signal source to put out full power, this number regardless of all other settings is fixed and will not change. The purpose of the gain control is to match the voltage of the input signal to the ammount that is required by the amp for full power. If you hook up a component that can only put out 2.5V and the amplifier requires 5V for full power then the input portion needs to apply enough gain to boost that 2.5V up to 5V (i.e. double). The problem you can run into is that any noise that is picked up in the interconnect on it's way to the amplifier was also just doubled along with the singnal. So you see that by using the lowest possible amount of gain you reduce your chances of amplifing extra noise along with the original signal. If your preamp cannot output a high enough signal and you use to little gain you will never get full power out of your amp. So it is a delicate balancing act.""

The signal is not amplified in a true sense of the word. I guess you could say the signal can be amplified, but it is not amplified by what most people think of as an amplifier in the receiver. Sounds like a gain control to me. I just want to clarify that there is not an amplifier in the receiver for the subwoofer.

 

[Rick_Brown]

Thanks, Kevin, for correcting me on using the term "amplifier", rather than "gain control" for the receover's sub level adjustment.

Getting back to the subject of this thread: Jeff, if you refer to the url thread that I gave in my previous post above, you'll see that there is a lot of opinion out there that you will have less distortion if you reduce your receiver's sub level from "0" to something like -3 to -6, and then use the sub's volume control to achieve the correct overall balance. I suggest that you try both ways and judge for yourself!

 

[Kevin Deacon]

Hey Jeff, no thanks are necessary. We don't want to confuse anybody who may already be having problems understanding some of the concepts associated with HT.

 

[David K. Johnson]

Hi Guys:

Just another bit of info - According to the guys at SVS, Rick's method is preferred. Their recommendation is covered on their web site. David