Volt tolerance when setting gain levels for two channel amp to drive one subwoofer.

[SoulSoak]

I'm trying to take precaution here when tuning my new setup. I have a RF 700s two channel amp (700rms @ 4ohm bridged) and am using it to power a single Alpine 12" swr12d2.

With my math, I come up with needing 52-53 volts bridged (26.5 volts per channel).

My issue is.. I can't set each channel to exactly 26.5 volts. While trying to set the voltage via multimeter, the live reading fluctuates by 3 or 4 volts up and down.

I.E. I get readings of 23 upwards to 29 fluctuating but averaging 26sh.

My concern is... if each channel isn't set to EXACTLY the same voltage level... can it damage the sub or amp etc? Is there a tolerance level? For examply if one channel is emitting 24 volts and the other emitting 28 volts, will it be a problem or possibly damage anything?

I plan to get a decent class D mono amp soon but at the moment I have to work with this.

Expertise advice is greatly appreciated. Thanks and God bless.

Click to read more...

 

[Jeffdachef 5,000+ posts]

I think its more of your multi-meter not in a steady position causing the fluctuation.

 

[CSCStang]

A 2 channel amp only has one gain control so when you set the gain using one output it will be set for the other too.

 

[SoulSoak]

A 2 channel amp only has one gain control so when you set the gain using one output it will be set for the other too.

My two channel Rockford fosgate 700s has two gain knobs... one for each channel. Am I missing something here?

 

[whitedragon551 5,000+ posts]

How many times are you going to post the same thread?

 

[SoulSoak]

How many times are you going to post the same thread?

Well, I realized General Discussion probably wasn't the right place. So I tried to relocate it to the Amplifier section. The came accross this Help section and figured maybe this would be the best place for it.

Thanks for your helpful response however. Let me guess, your next course of action is to close and/or delete this thread to prevent me from getting the answer/help I'm looking for? Or wait... maybe just take it to a whole other level and just ban me from the forum?

Just looking for an answer, and, judging by the responses I've received thus far I figure I had been inquiring in the wrong forum sections. Sorry if I've offended you.

Now before this thread becomes hijacked by nonsense, can someone with expertise please read my inquiry above and provide me with some helpful insight. Thank you for your time.

 

[CSCStang]

Well, I realized General Discussion probably wasn't the right place. So I tried to relocate to the Amplifier section. The came accross this Help section and figured maybe this would be the best place it.
Thanks for your helpful response however. Let me guess, your next course of action is to close and/or delete this thread to prevent me from getting the answer/help I'm looking for? Or wait... maybe just take it to a whole other level and just ban me from the forum?

Just looking for an answer, and, judging by the responses I've received thus far I figure I had been inquiring in the wrong forum sections. Sorry if I've offended you.

Now before this thread becomes hijacked by nonsense, can someone with expertise please read my inquiry above and provide me with some helpful insight. Thank you for your time.

Didn't realize it had two, my bad. Try to keep the dmm probes solid on the terminals when you're setting the gain. Sometimes it will fluctuate a little, but as long as its close to the set point youll be ok.

 

[SoulSoak]

Didn't realize it had two, my bad. Try to keep the dmm probes solid on the terminals when you're setting the gain. Sometimes it will fluctuate a little, but as long as its close to the set point youll be ok.

So there is a slight tolerance, greatly appreciated, thanks. One more thing though, when setting the amp gains I tune my head unit to flat with no eq boosts etc. However, the amp has a wired bass control remote knob. So I want the remote knob turned all the way up to max when setting these gains correct? Because if it's set to the minimum and I tune the gains to the proper voltage... if I were to turn the bass control remote knob up to max it would then cause excess in voltage ultimately providing too much power correct?

 

[CSCStang]

Is it a gain knob or a bass boost knob? Gain knob maxed. Boost knob? I wouldn't use it at all.

 

[SoulSoak]

Is it a gain knob or a bass boost knob? Gain knob maxed. Boost knob? I wouldn't use it at all.

It's a dB knob so I'd assume it's a bass boost knob. Should I just disconnect it then and dial the voltage in without it and run the amp that way? Thanks for all of your input

 

[CSCStang]

It's a dB knob so I'd assume it's a bass boost knob. Should I just disconnect it then and dial the voltage in without it and run the amp that way? Thanks for all of your input

Yeah I would take it out. You may have a more stable reading without it too.

 

[SoulSoak]

Yeah I would take it out. You may have a more stable reading without it too.

Thanks a lot man you rock. Hate to do it but one more thing. When I am tuning the voltage of the channel, I am just playing a song. Do you recommend I download and use a tone/bass note test? Or is playing just a normal song just fine?

 

[CSCStang]

Thanks a lot man you rock. Hate to do it but one more thing. When I am tuning the voltage of the channel, I am just playing a song. Do you recommend I download and use a tone/bass note test? Or is playing just a normal song just fine?

40-50hz test tone. -5db is what I use.

 

[n2audio 5,000+ posts]

Not using a tone is probably the cause of your gain setting problem.

With a tone -- getting it within a tenth may be difficult. Getting it within a volt will be simple.