Subwoofers cut out at high volume, new development

[Toyotat1001227]

Okay hers my problem, i ran this amp with 1 sub and it was fine for a year. I added another sub and bridged them, i also messed with the input sensisivity. If the input sensitivity is my problem. Do i turn it down (giving more power to the amp) or up?(giving less power). Currently it's about a quarter from giving the amp full power. I messed with it because the amp puts out the right rms at max and the max wattage is fine for my subs as well, so i figured itd be fine at almost full blast.

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[ace_800 5,000+ posts]

Whats the ohm load to the amp now? What amp and subs(D2/D4?) are you running?

 

[Jepalan]

What make & model amp?

What exact make and model subs? Single or dual voice-coils and what impedance (ohms)?

How is you amp connected to power & ground?

You typically turn your input sensitivity down if you are cutting out, but it depends on amp model. You should set gains based on RMS watts of the amp, not peak watts.

Bad ground connection is another common problem - make sure you have a short ground wire direct to a chassis bolt and that all paint is sanded off.

 

[Toyotat1001227]

okay so i have this exact same problem with another amp and sub setup. this time i bought both from a car audio guy so its tuned right. so this just somply means my battery cant keep up right? so i need a capacitor or another battery?

 

[Jepalan]

Need details:

What make, model & year car?

What make & model amp?

What make & model sub(s)?

 

[bbeljefe]

First of all, a correction. Turning the gain down does not "give" the amp more power and turning it up doesn't take any away. The gain is meant to match the source signal voltage to the amplifier's input sensitivity. Once set (properly), it should not be changed regardless of the impedance or the number of the subs.

You mentioned that the gain is currently set at 3/4. Unless you have a line out converter being fed by a factory head unit, that is way too much gain. If it's an aftermarket head unit with the front stage powered by the head unit, the gain may need to be about half way up but if the system is all powered by external amps, it should be between ¼ & 1/8 of the way up, depending on the preamp voltage your head unit sends.

 

[Toyotat1001227]

1997 Toyota t100 with red top optima, 2 12 inch pioneer subs not sure the model. There blue. And an alpine 760 watt pioneer amp

 

[Jepalan]

Measure the DC voltage between the amps power and ground terminals when the sub cuts out.

Also - are you sure the subs are wired for a proper ohm load matched to the amp? Without the sub model I can't confirm. I'm not sure what an Alpine-Pioneer amp is either.

 

[Toyotat1001227]

Oops i meant pioneer 760w amp lol. And i know the sub is 4 ohms 150w rms and 800 max

 

[Toyotat1001227]

Sub model

TS-W301R - 12" Component Subwoofer with 800 Watts Max. Power | Pioneer Electronics USA

 

[Jepalan]

If you have the subs wired in parallel then they are presenting a 2-ohm load to the amp. If your amp is a pioneer 760w 2-channel model, then it can only handle a 4-ohm load. You are overloading the amplifier if you have it bridged to a 2-ohm load. If you have a 2-channel amp, the best way to wire your subs would be to put each one on its own channel separately.

You really need to measure DC power at the amp under load to see if you are getting excessive voltage drop as well. If so then your suspicions of a weak electrical system my be true. VOlt meters are cheap, or borrow one.

 

[Toyotat1001227]

My amp isn't the new model 760w. I'll have to look at it tô get a specific model. I do notice my lights dimming on hard hits. That points toward a voltage drop as well right?