# A little help with my sub?



## whubbard (Oct 31, 2007)

I have a Sunfire True Subwoofer MK II that has been in my home theater setup for quite some time. During this time there has basically been non-existent bass. Well I'm trying to fix that and I have REW setup and a BFD (from a previous project) but sadly I can barely get any bass at all to even set it up. When I can here the bass, it's an extremely fine line between there and the subwoofer clipping. :huh:

The sub basically goes from soft, mild bass to thump, thump, thump I hate you so I'm going to clip now. :foottap: Does anybody know the best way to test what's wrong here? Should I grab other amp and trying hooking it up directly to see if that helps? Do you suspect the built in amp is having issues or is it possibly the drivers and not the amp. (I'm assuming amp because the way the drivers are acting I've only seen before with clipping subs). 

I'm sorry if that was confusing and I appreciate all the help I can get.


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## Mike P. (Apr 6, 2007)

The MK II is capable in room of 105 db at 25 hz, from there the low end begins to drop off. What size room is your sub in?


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## hjones4841 (Jan 21, 2009)

Is the crossover set too low? That could explain what you are hearing. A bad amp could also, but likely not if it has been this way since new.


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## whubbard (Oct 31, 2007)

First off, there is no output below 45hz and the crossover is set to 100hz so doubt that's it. I've got a scope so if we can't think of anything else I can always see if it's actually clipping or something else.

Mike, the room is quite large. It would be hard to quantify because it opens up into other large spaces. I'm not expecting anything incredible here, but when I mean that I don't hear anything, I mean with my ear 12" from the driver, no from the listening position.


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## Mike P. (Apr 6, 2007)

What receiver is sending the signal to the sub?


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## whubbard (Oct 31, 2007)

Currently it's an Emotiva UMC-1 to the Behringer to an ART Cleanbox II to the sub. It was performing exactly the same though when going Emotiva UMC-1 directly to the sub.


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## Mike P. (Apr 6, 2007)

You definitely have an issue. Which Behringer? Are your speakers set to small on the UMC-1? Did you do the level calibration?


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## whubbard (Oct 31, 2007)

I did the level calibration. It wouldn't create any sound from the sub. When I do the EmoQ it does clip the sub multiple times in the process. Ironically it thinks the sub should be at -8dB (probably because of the clipping SPL).

I'm using the DSP1124p (BFD).


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## hjones4841 (Jan 21, 2009)

Hook a MP3 player directly to the sub to eliminate anything else in the signal chain. If still no output below 45, then it is the sub amp or driver - more likely the amp. I am sure you took the BFD out of the chain as part of troubleshooting, right?


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