Tuning Amp

**isucyclones3** · 02-19-2010

First off i have 2
Rockford Fosgate Punch HX2 RFD2212 12" Dual Voice Coil Subwoofer at Crutchfield.com

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Kenwood KAC-9103D Mono subwoofer amplifier 900 watts RMS x 1 at 2 ohms at Crutchfield.com

I have them in a sealed box wired for 2 ohms. I read on the internet to turn gain and bass boost down, then turn volume control on stereo all the way up until it distorts. After doing so go back to your amp and turn the gain up until your subs distort. I did that but they never distorted and i had the gain all the way up. Is it ok if the gain is all the way up?

**matt5112** · 02-22-2010

yes, but are you sure you know what clipping sounds like?

**isucyclones3** · 02-23-2010

I never have heard it before but I listened closely but didnt hear anything. I have it turned down now because i was unsure. I will try again in the next couple days and listen again. Is there a way your can describe it to me?

**matt5112** · 02-23-2010

http://www.youtube.com/watch?v=3Gmex_4hreQ&fmt=18

http://www.youtube.com/watch?v=DRyIACDCc1I&fmt=18

This is just SMALL clipping... DM is REALLY clipped horribly though....

Couldn't find any good examples.

**isucyclones3** · 02-23-2010

Is this a good example of what i should be listening for?

YouTube - Ground Zero 120 SPL clipping

or http://www.youtube.com/watch?v=Kb-ED...eature=related

**matt5112** · 02-23-2010

yeah, but thats not the speaker, thats the mic.

And bass i love you has a peak at 7 Hz... thats just stupid to run on a sub in a ported box without a highpass on it.

**isucyclones3** · 02-23-2010

So on the first video you said it was the mic making that noise. Does he have the gain turned up to much?

**matt5112** · 02-23-2010

I would never be able to tell you since the mic picking up the sound is clipping from the sound pressure.

**isucyclones3** · 02-23-2010

Oh sorry, the mic on the camera, i was confused haha. What is the subsonic filter on my amp for?

**matt5112** · 02-23-2010

crack open the owners manual and it'll explain it.

If its not there, then you don't have one.

It just prevents you from blowing up your sub by putting a thousand watts on a sub at a frequency where its mechanical power handling would be 50 watts.

**isucyclones3** · 02-23-2010

Well i bought the amp at an auction used so i dont have a manual but i know i have one because of what crutchfield says and i have seen the setting on my amp. It has a switch with 3 settings, 0, 15 or 25 hz

**matt5112** · 02-23-2010

oh true. Set it just below the resonant frequency of your port if its in a ported box and it'll keep your woofer safe.

Edit: Wait you're sealed, just leave it at 0

**isucyclones3** · 02-23-2010

Ok thanks, and I read to have my lpf from 50-120 so i put it at 70. Is that ok?

**matt5112** · 02-23-2010

yup

**CTKGP09** · 02-23-2010

start with all settings on the amp at zero. turn volume up to the loudest that you will be playing it. pick your frequency range on the amp and slowly turn up the gain first. the turn up the bass boost for a little more kick. do this until u hear distortion then turn it back down intil all distortion is gone. it takes alot of practice and a good ear

**isucyclones3** · 02-23-2010

Alright, thank you both. I will mess with it tomorrow after school.

**matt5112** · 02-24-2010

your crossover isn't supposed to be guesswork. you should have a range where you predict would work well then experiment in that range.

**chickenfried** · 02-24-2010

Originally Posted by CTKGP09

start with all settings on the amp at zero. turn volume up to the loudest that you will be playing it. pick your frequency range on the amp and slowly turn up the gain first. the turn up the bass boost for a little more kick. do this until u hear distortion then turn it back down intil all distortion is gone. it takes alot of practice and a good ear

i have been told the same thing. actually did it on my system and it works swell. if you ahve the boost up on the amp i would leave the gains lower tho. untill you get a better feel of what sound you like and the sub actually broke in. numerous people have told me to leave the boost alone, it all comes down to preference

**matt5112** · 02-24-2010

Bass boost = STUPID.

Unless you like one note to be louder than all the rest.

But then you only have fun with certain songs.

How about building to enjoy ALL the notes which means ALL the bassy songs instead of just finding "that one song that bumps so sick".