ok, first off I know I am gonna get flamed just for asking this question but I really cannot tell if my PowerBass m-12 is blown. it is a 350 watt sub and I have it hooked up to a PowerBass ASA 300.2 amp (300 watts rms X 1 into 4 ohms). the problem is that when I try to tune the gain up very high the sub starts distort, I have used a multimeter to verify that the amp itself is not clipping but I do not have access to a oscilloscope. I never turn my system up that loud so I really do not think there is a way it could be blown. yes I do consider myself pretty smart about car audio and I do know that the gain isn't a volume control.

Any suggestions?

 

No idea...might try the guys in the Audio/Security forum

 

Very hard to say, could just be the box.

Try this...
Remove sub from box, using both hands move the subs cone in and out making sure the cone is moving "squarely" if you hear/feel any scraping the sub is blown, [burnt VC].
A little harder to do with a 12" sub but hold the sub by it's magnet up to your ear, [cone facing ear] using your other hand give the magnet a good smack/thump if you hear a "rattling" sound, sub is blown, [separated VC]
You can also meter the VC to get a DC resistance reading although not real helpful unless it is way off the VCs impedance, EG; if it is a 4 ohm VC and you get a reading of 3.6 it tells you nothing, if the reading is below 3 ohms or above 5 ohms then it tells you you probably have a burnt VC. 94

 

what he said ^^

 

I'm pretty sure that it is not the box, I forgot to mention I have it in a ported sub zero box of that helps at all. I am too lazy to take the sub out of the box but I will put my ear next to it and see if I can hear the raspy sound and I will also try the resistance. the weirdest part is I always had the gain way down because I didn't want to blow the sub as it was $139 and I don't have the money to keep buying subs.

 

Ok here are my indifinitive test results, there is no raspy sound from the voice coil, and the resistance is 3.6 ohms. Maybe I'm just expecting too much out of this sub/amp setup. before I had a 150 watt lightning audio sub on a 150 watt Kenwood amp in the same box and it had just about the same volume as this setup.

 

Box volume and port volume are critical to a subs performance, just swapping out a sub and using a "bigger" amp is not the way to get more bass.

You have a 350W continuous sub and driving it with a 1x300W RMS amp, so to start you are underpowered, not by much, but probably enough that the amp is clipping before you get to full potential of the sub.

What is the internal gross volume of the box and what is the port size, [diameter and length]???

Optimum vented box for that sub is 2cuft gross with a 4"x11" port, box tuned to 35Hz.

If the box is exactly right you can probably get away with the 300W amp, although I would be looking for a 400W RMS into 4 ohms mono block sub amp. 94

 

just going off the top of my head the box is 1.5 cu ft and the subs manual specifies 1.5-2 cu ft either ported or not, I don't know the dimensions of the port but it is tuned to 33 hz.

 

http://www.powerbassusa.com/products...pecs_m_12.html

Are we talking about the same sub? 94

 

yea we are. I have had 3 subs in the past, so off the top of my head info isn't very accurate.I didn't know it needed a 2 cu ft enclosure.
I do have a 1.25 cu ft sealed box also do you think that would work better?

poking around on the power bass website the S-12 subs seem to be a way better match for my amp and box. but I don't want to buy another sub.

I may just sell my sister this sub and go buy the s-12 because she wants a system anyway.