Amp input sensitivity

[Kenyanbasshead]

Right guys,

Im setting my gains on my amps for my subs. 2 subs and 1 amp per sub. 3500rms at 1 ohm each.

My headunit (kenwood 4016bt) has 3 rca preouts at 4v.

Now i have used an oscope to check my signals. I can put the headunit up 80% with out clipping from the deck.

Now when attaching the oscope.to the amps outputs i can turn my gain(input sensitivity all the way to 0.2v) with out any clipping..... output voltage is at 178v with input sensitivity turned all the way to 0.2v and still no clipping....

Im just wondering if any of you have also experienced this.

I DO NOT want to blow anything.

I do not play at full volumes daily.

But i do want the full potential out of my amps so that i can adjust the bass from the headunit.

I look forward to your replys.

Click to read more...

 

[Kenyanbasshead]

Anyone?

 

[hispls 5,000+ posts]

. output voltage is at 178v

Only amp I've ever seen make that kind of voltage is the Crown A6000GTi. You're doing something very wrong if you're reading that out of an amp that's designed to drive 1 ohm.

That said, if you bought this to compete you should be setting gains with a Termlab, if you bought it to listen to music you should be using your ears.

 

[JohnKuthe]

Only amp I've ever seen make that kind of voltage is the Crown A6000GTi. You're doing something very wrong if you're reading that out of an amp that's designed to drive 1 ohm.
That said, if you bought this to compete you should be setting gains with a Termlab, if you bought it to listen to music you should be using your ears.

Yeah, that's what I thought too. He said "My headunit (kenwood 4016bt) has 3 rca preouts at 4v." which I interpreted as his preamp outputs are 4V, which seemed too high in my limited experience. Preamp outputs to a power amp are generally in the 1V range, but little power handling as they are designed for high impedance inputs to a power amp.

John Kuthe...

 

[Kenyanbasshead]

Only amp I've ever seen make that kind of voltage is the Crown A6000GTi. You're doing something very wrong if you're reading that out of an amp that's designed to drive 1 ohm.
That said, if you bought this to compete you should be setting gains with a Termlab, if you bought it to listen to music you should be using your ears.

Thanks for the reply. The only problem with setting it by ear is that there are 2 subs and 2 amps. So how would i match them identically by ear?

I dont do spl comps. Just daily pounder.

 

[Kenyanbasshead]

Yeah, that's what I thought too. He said "My headunit (kenwood 4016bt) has 3 rca preouts at 4v." which I interpreted as his preamp outputs are 4V, which seemed too high in my limited experience. Preamp outputs to a power amp are generally in the 1V range, but little power handling as they are designed for high impedance inputs to a power amp.
John Kuthe...

The headunit has 3 rca out puts. Fron, rear and sub, i put a multimeter and an oscope on the rcas and the voltage was 4.4v.

And on the amps output when turning the input sensitivity all the way to 0.2v i saw 178volts and still a unclipped signal.

Maybe the electrician is doing something wrong. But yeah. Thats why i decided to ask here.

 

[hispls 5,000+ posts]

The headunit has 3 rca out puts. Fron, rear and sub, i put a multimeter and an oscope on the rcas and the voltage was 4.4v.
And on the amps output when turning the input sensitivity all the way to 0.2v i saw 178volts and still a unclipped signal.

Maybe the electrician is doing something wrong. But yeah. Thats why i decided to ask here.

You should gain one by ear then voltage match the other one to it.

If you're not using a Crown A6000GTi or high voltage Brazilian your amps are NOT making 180V AC period. If you are measuring this you are doing something very wrong or your DMM is faulty.

Assuming your amps legitimately make 3000W into 1 ohm you should be seeing more like 50-55V out of them.

 

[Kenyanbasshead]

You should gain one by ear then voltage match the other one to it.
If you're not using a Crown A6000GTi or high voltage Brazilian your amps are NOT making 180V AC period. If you are measuring this you are doing something very wrong or your DMM is faulty.

Assuming your amps legitimately make 3000W into 1 ohm you should be seeing more like 50-55V out of them.

Thanks for your reply. The amps are german and make 3500rms at 1ohm. I calculated that i should be seeing 59.1 volts....?

But doing 1 by ear sand then matching the other with the dmm is a good idea. Didnt even think of that. But doesnt playing one sub in the same box damage something?

Thanks again for your reply.

 

[hispls 5,000+ posts]

Thanks for your reply. The amps are german and make 3500rms at 1ohm. I calculated that i should be seeing 59.1 volts....?But doing 1 by ear sand then matching the other with the dmm is a good idea. Didnt even think of that. But doesnt playing one sub in the same box damage something?

Thanks again for your reply.

You cannot strap those two amps? Yes, playing only 1 sub if they share airspace could get ugly. You could simply match gains with the speakers disconnected at the amp. Might not be terribly accurate but should be a good place to start.

My big worry is that if you are reading 180V out of the amp there is something wrong with how you are measuring or your meter so any results you have from there are very suspicious.

 

[Jeffdachef 5,000+ posts]

If your gain is at max and its still clean, its completely wrong.

Just start off with the gain at 30% for each. See if the output at its highest for you, then voltage match them. If not, raise them up a little bit.

Slight differences in power wont hurt the subs. Learn to recognize the sound of clipping.

Usually a change in bass tone along with a big jump in perceived loudness.