Something Wrong with my Pre-Outs

[qkassidyw 10+ year member]

So I was changing up my Subs today and I was metering the output on my amp (Rockford 1000.1bd) and I just have one Dual 2 Ohm Type R hooked up at 4 ohms. I wanted 600 RMS so I did the calculation and got 48 V. The max I got was 23V with the gain turned all the way up (and the crossover off). I thought something was wrong so I tested my Pre-Out voltage and was getting .15 Volts, I checked my 4 channel pre outs and was getting the same. I was using a 100 Hz test tone (only one I had on my iPod) and I am pretty sure there is something wrong with my pre outs...

Any ideas?

I have an Alpine IDA-x001 and they are supposed to be 2V.

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[Jeremy M 10+ year member]

isn't it like 2volts at it's peek?

i coudl be wrong

 

[alex5857 10+ year member]

do you have the sub out all the way +15 (or w.e.)?

 

[civicman07 10+ year member]

I had a smiliar problem when setting my amp, found out the patch cord between my sub amp and line driver was messed up, changed it out and now its fine.

 

[qkassidyw 10+ year member]

It is 2V peak so RMS that should be 1.4 at its peak....the sub was at 3/4 volume at 3/4 and it did it on the sub out and the regular pre-outs...

 

[alex5857 10+ year member]

wut?

 

[Immacomputer 10+ year member]

Did you have any cross overs running on the headunit or amp?

 

[qkassidyw 10+ year member]

Did you have any cross overs running on the headunit or amp?

Nope, had them all off....initially I had my sub amps on and it was at 19V but when I turned it off it went to 23 volts.

I'm wondering if my test tone was at -dB...I'll find a better tone and try it again.

 

[Immacomputer 10+ year member]

What you should consider doing is turning the gains all the way down on both amps and then slowly turn up the volume on the head unit and listen for the volume level that it distorts at. When you hear clipping, back down on the volume just a tad and then set your gains at that volume level. Don't go by the 3/4 way up method as all headunits are different. My Eclipse unit played clean with a flat EQ up to 73/80 and I set my gains using a volume of 70. My current JVC unit clips around 40/50 with a flat EQ. Try this with a couple different tones so you can really listen for clipping.

Here are two test tones for you to use:

http://files.filefront.com/100+60zip/;11699840;/fileinfo.html

One is 60hz and the other at 100hz and both are 0dB and encoded in 24bit .wav files. I recommend burning them to a CD and using that as it will give the cleanest signal.

But really, start by using your ears and then use tools to check your ears. Multi meters are very useful and handy but there are somethings that they're not reliable for. One is for setting gains. People don't want to believe this but it's true.