Powering the XXX. Need help with this gain situation.

[528hz 10+ year member]

Well, the 04 XXX is up and running and I've got the American Bass VFL 150.1 powering it for the moment. I'm very impressed with this amp and the XXX......well, jump on the bandwagon everyone because everything you've heard and more about this sub is 100% true. Now, I've set my gains with the DMM, but since this amp is rated at 150x1 @ 4 ohms, the EXACT RMS of the amp has been up for debate, but I have went by the fact that this thing will do the 2000x1 @1 ohm. This is kind of long and detailed so bare with me.

Here is my box & electrical setup:

2 Batcap 800s

stock 650 CC battery

150 amp, stock Bosche alternator

2cu @ 33 hz

Hers is my predicament:

I used a 50hz test tone to set the gains on the DMM to 42.42v ( theoretically 2000 watts) the first time. The volume on the HU was on 67/80 After I set the gains, the sub was moving great, but it still felt like it needed more power.

So the second time around, I adjusted the gain by ear using the same 50 hz tone and same volume level. I could actually hear when the amp started to clip, because the amp itself would start to sound like it was reving up, so I knew when to back down off it. I set it to where the amp the made no "reving, clipping" sound and hooked the sub back up. It was a hell of a lot louder the second time

After I set it by ear, I put the DMM back on it and I got a reading of 53.1 (2800+ watts)!!!! There is no distortion or clipping (listening by ear) coming from the sub unitl almost full volume, but this didn't make any sense to me. There is no way the VFL does that much power.

Are my gains way too high or is this amp not making enough power? The XXX feels like it could take 2500 RMS according to the RMS consensus on the VFL.

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[skadude016 5,000+ posts]

Interesting. Do you have an amp clamp? So that you could see what kind of power it really is putting out?

 

[528hz 10+ year member]

No I don't. I was also thinking that maybe my box is too small in order to get it to move pretty well in the 50s volume measurements on the HU.

Am I right in the sense that when the amp starts to rev up, it's clipping?

 

[528hz 10+ year member]

Peso for anyone's thoughts.....

 

[skadude016 5,000+ posts]

No I don't. I was also thinking that maybe my box is too small in order to get it to move pretty well in the 50s volume measurements on the HU.

Am I right in the sense that when the amp starts to rev up, it's clipping?

may not be clipping. But for longer life I would leave it where you have it.

what size XXX and box size and tuning?

 

[528hz 10+ year member]

12", 04 motor

Box: 2cu. tuned @ 33

 

[pawn man 10+ year member]

the vfl amps are very strong. it is conservatively rated at 2000 watts.

 

[TrIgZ 10+ year member]

i work for bob at american bass but i actually work at one of his rim shops. i used to work there until the rim shop guy got fired and all our dealers told us that amp does over 2500.

 

[innsanes 10+ year member]

Great sub for sure, i own the 15" 05 model, Sub is too F in loud for me. I don't think i even daily drive it at its full potential.

 

[thevic24 5,000+ posts]

the right voltage for 2000 watts at 1 ohm is 44.72

 

[L7BASSHEAD 10+ year member]

12", 04 motor
Box: 2cu. tuned @ 33

possibly a bigger box is needed?