Just played my DIY sub for the first time. Something is not right.....

No, the problem clearly lies somewhere else. I just got a Pioneer Elite SC-55 - plenty of output on the sub channel. So far all the AVRs and all the pro amps I've had a chance to try were able to successfully interface with the regular subwoofer output. How are you EQing the sub? That's the first place I would look for a problem. Take it easy so you don't damage anything, that much power should be rocking the house.

What are the signal lights on the amp doing when this is going on?

You might have the voice coils wired out of phase.

Definitely sounds like the coils aren't wired right.

If its not hard to do, I would check the wiring anyway. Sometimes we make mistakes even though we've done it right a thousand times.

Also maybe a stray wire is grounding out on the sub or amp somewhere. All it takes is that one little "hair" touching something to throw everything off.

Just my input, that's the first thing I would do. Because if any of this is the case, the more you make the amp/speaker deal with it the higher the chance of ruining something.
Edited by mix1983 - 1/2/13 at 4:28pm

A sealed sub with no EQ is going to sound like it has no deep bass, tons of mid-bass. You can't just hook it up to a pro amp with no EQ. Either you need a ported design or you need to figure out how to put a nice 6db/octave (or so) boost into that sub most people use the FDP or the MiniDSP, or else they buy an amp that has built-in DSP like an iNuke or a Crown XTi.

That's not necessarily true. It all depends on the Q of the sub and how it couples to the room. Here's a set of sealed subs with no EQ.



It's not pretty and can definitely use some EQ to flatten it up, but it's not certainly devoid of deep bass.

TenTonBass, I may or may not have the solution to your problem. I had a similar situation as yours as I have the XLS2500. Those crown amps have some basic crossovers built into them. I acidentially had a HPF (Highpass) set at 99Hz on the crown amp so the subs were trying to reproduce high frequencies instead of low frequencies. Once I changed the crossover to a LPF (Lowpass) all was good. What does yours main screen say? Mine says stereo lowpass and I believe that yours should say bridged lowpass. You might want to try a 83Hz or so lowpass filter. Another issue that I had was that my volume on my processor wasn't high enough to give the amp enough juice. You'll need to get your receiver/processor volume to around -10dB to get some decent output from it. I had to set my speakers to -15dB so that I could pump up the volume on my onkyo to get enough juice sent out to the crown. Another alternative is to use a bump box such as a samson. I went that route at first and it worked great but I didn't want to have too much stuff in my signal chain (bump box and a MiniDSP) so I tried that method and it worked well for me.

You can read this post to see what I'm talking about referring to the levels. Disregard the references to the MiniDSP as the implementation is the same:

http://www.avsforum.com/t/1443652/minidsp-require-signal-boost-with-pro-amps#post_22683367

sorry to hear about your frustrating situation.

just to test the wiring on the driver, connect the sub to a 9v battery and make sure the cone moves when it is connected. if it doesn't move, something is wired wrong with the driver.

"I kind of kept the same receiver settings as I had on my old sub..."

this may be part of the problem. are you running redirected bass? what do you have your subwoofer trim level set to?

are you sure that you have the amp set up properly for bridged mode?

"bridge bypass" should be fine. In fact, I would switch it back to "bridge bypass" to avoid having the lowpass active, since you don't need it. It was a good suggestion from Audiophile1178, but it sounds like that wasn't the problem.

-Max

Also, which terminals are you using on the back of the amp for bridge mode? It should be the two red ones.

If your wiring is correct, also make sure each voice coil is wired properly on the sub. use the 9v battery test on each coil to make sure there wasn't a human error made during manufacturing. +9v on each coils +/red terminal should push the cone out. Might as well be thorough testing if you are pulling things apart.

If you have a voltmeter, might be a good idea to check how much voltage you're sending, to ensure your peak is within the limits of your design

Explosions in certain big budget films have such low frequency content they will either clip or max out your sub's excursion. If it's clipping, turn on the limiters. If you're out of excursion, you need another sub, or you need a high-pass filter.

glad you got it working ttb

TenTonBass, Glad I could help. You problem sounded just like what I had experienced. Instead, I bought a Samson S-Convert which worked fine but then I thought about that idea of adjusting the levels accordingly to get rid of the Samson. If you think about it, the bump box just raises the levels up higher. The same thing can be done from adjusting the rest of the speakers by lowering the levels. It was initially weird to me having the volume at -8dB or so as the highest that I would've previously gone was -18dB but it all makes sense now the more that I read about it on this board. I wonder how many people are using bump boxes that don't need to?

The idea orginally came to me from reading how people calibrate and levels their subs. They say to lower the peaks and try to raise the nulls. Well, as I thought about it the rest of the speakers were my peaks and the sub was the null as there wasn't a lot of sound coming out of it. There are tons of other people on here that bump their sub levels all the way and to me it seems like it's the wrong way to go about it. I don't know if the way that I did it is the right way or the wrong way but it does seem to work (at least for me).

Pioneer AVRs do not EQ the bass the same way Audyssey based units do. Besides, if you got a proper EQ you would be able to dial in the exact bass you want instead of guessing and dealing with it in such broad strokes.

TenTonBass, I don't have any "real" subs at the moment in my condo so I have never experience that "DEEP" bass that you all know and love. What I currently have is two JL 10W1v2's in a sealed truck box that was built back in 1998 which was built for a 1993 Ford Ranger Regular Cab which had in it two old sckool JL 10W0's. My 10W1's just happen to fit in the box. My 24" ported boxes for my two JL 10W7's are almost done. I don't have any correction mics or what not but what I do have is an ONKYO PR-SC885 Processor with regular Audyssey, a MiniDSP and a Radio Shack Digital SPL meter. This is what I plan on doing when my sub boxes are done:

1. Calibrate the sub levels to the same level or slightly hotter (2-3 dB's) than the mains.
2. Play test tones from 10Hz - 100Hz in increments of 5Hz and take readings from my Radio Shack SPL meter to manually make a graph (maybe in excel). I might change it to 3Hz increments but I'll see how it goes.
3. Use my findings from step 2 to adjust my peaks and nulls using the MiniDSP.
4. Repeat steps 2 and 3 as needed until satisfied.
5. Repeat step 1 to see if anything changed. If so, adjust accordingly.
6. Enjoy!

I don't know if this is the right method of doing it but it seems most logical to me. Here's a comparison of the truck box that I have now (in yellow) and what I'm going to have (in blue). I think that the two JL 10W7's which will be getting ~775w a piece hold their own fairly well to other (much larger) speakers that are mentioned here. If I had a house and could do it all over again I think that i'd be getting four of the new SI 18" HT subs but in a condo I think that would be a bit too much for my walled neighbors so i'm going to have to be satisfied with my two ported 10's. I think that it'll serve me well for the next few years until I graduate from college.

There is a need for a proper EQ to get the most out of your sub. Good luck with these 'other methods'. If you change your mind, three options stand out: MiniDSP, Feedback Destroyer Pro, and Audyssey. Another choice is an amp with DSP built in (my solution). If you think MCACC is going to do it for you, you are never going to have a sub that sounds 'just right'. Audyssey EQs bass, MCACC will not . Do some Googling, you'll see.

Edited by imagic - 1/5/13 at 5:23am

Is that a reading from the LP or close Mic or something else? You can 'get lucky' and have a sub that plays somewhat flat with no EQ, once you find the proper position. I'll guess that's not happening for the OP. EQ it is - or else it's the crawl test and countless readings with no guarantees. As you point out, a sub will benefit from EQ, even if it is extending below 20Hz.

That is measured from the LP

Aces, that's a nice curve for sealed at LP, no EQ. Having two subs does help as well.