I'm about to give up, help please!

I am having trouble getting my sub to pound in my 1991 Nissan Kingcab. I have a Clarion head unit with Pioneer 2 way 6.5" speakers in the front. I recently purchase the Pioneer GM3000T 200w max 2 channel amp, which supposedly puts out 100W x 1 when bridged. I have an 10" MTX 6000 series sub that was sold to me but when I took it out of the box it has a remanufactured sticker so I will return it soon. The kid working there lied to me. Anyways I also have a Rockford Fosgate 10" P110S4 subwoofer. MTX recommends about 0.5 - 1.0 cubic ft. sealed for that sub and Rockford recommends 0.65 cubic ft. sealed enclosure. The enclosure the MTX came in is over 1.3 cubic ft, but that's measuring on the outside... so factoring in the 3/4" wood and the displacement of the sub it's probably around 1.0.

I have tried hooking up the MTX bridged and it won't pound, it will barely do anything. Same with the Rockford, it will barely do anything. My cheapo speakers up front are putting out more bass than the sub does. The only way to actually hear the sub pound is to adjust the balance on the head unit all the way to the rear and then turn the volume up to about 30, which normally way too high a volume level.

Does this sound right? I also tried a crappy Pyramid 1600W max 2 channel amp bridged and same thing. Since I have tried 2 amps and 2 subs I don't know what is going on. Is it because it's a sealed box?
I have a wiring kit I got from Wal-mart that's rated for 550 W max, 275 W continuous.

Any help you guys could offer would be great. I've always wanted a sub in my truck but I don't want to have to return this stuff and give up! Thanks.

what's the impedance of the subs and how is the gain on the amp set?

4 ohm subs and I've tried the gain on all settings it doesn't help! I usually try it with the gain around 60% though.

hmmm

well this won't affect anything, but your box is a max of .88cf, minus sub displacement, so closer to .8cf. That's if it's a perfect cube, if it's rectangular it will be even smaller than that. That size is fine, I'm just letting you know so that if you need to know the box size for some future sub or whatever then you'll know.

as for the problem, is the amp set to lowpass? what is the cutoff frequency set at? which preouts on the headunit are you using (if it has more than 1 set)?

The box is almost a square... 14" x 14" by 12". Did you just calculate by subtracting 3/4" off of each side?

I have tried low pass on and off. I don't know about the cutoff frequency. The headunit has two sets of RCA plugs - front and rear, I've tried both.

Is it a huge deal that my head unit doesn't have sub outputs? I could have gotten that when I got my head unit a few years back but I didn't.

well first I assumed it was a cube, but yes then I subtracted 1.5" off of each side (2 walls). If it's 14x14x12 then it's .95 minus sub displacement (looks like I did too much rounding when I found it before ;)), so around .9 after sub displacement.

does your headunit have a highpass feature for your front and rear speakers? It's not a big deal that you don't have sub preouts, as long as the preouts that you're using instead aren't highpassed.

Do you have something cross wired?

I was wondering how you got to .88 because I subtracted 1.5" off each side as well. Anyways I don't think it has a highpass feature. When you say preouts you mean RCA cables right? My head unit has 2 - one front and one rear.

I don't think I have anything cross wired. I have checked everything over a bunch of times and read the instructions for the sub, amp, wiring kit and head unit. For the wire from sub to amp, I am using 14 gauge home speaker wire, it has copper and silver color, I always use copper color as positive but it doesn't say on the package. Does it make a difference which wire you use as neg. and pos.?

you can use either color, just dont get it mixed up. its common to use copper as positive. Yes those are your front and rear pre outs. I didnt see it mentioned in this thread so im gonna ask... have you checked your ground wires.. particularly the ground wire from your amp. The wire terminal on the amp labeled "GND-" should be connected to a bolt which is directly connected to the frame, and it should be a rather clean connection.

yeah, those rca plugs output the signal before it reaches the headunit's internal amp -> "pre-amp outputs" -> "preouts"

as for the wires, no it doesn't matter, not only does it not matter which of the 2 wires you use as postive, it doesn't even really matter whether you wire the sub's + to the amp's + or the sub's + to the amp's - ("backwards" so to speak). It would sound slightly different if you wired it up backwards, but nothing like what you're experiencing.

The only thing I can think of is that your headunit is highpassing the signal, and then the sub amp is lowpassing it, so in the end everything is filtered out and barely anything is reaching the sub.

Try taking a cd or mp3 player, just some kind of portable player, get one of those cables that converts the 1/8" headphone plug to a pair of rca plugs (you can find them at best buy or radio shack), and then plug those into the amp. Keep the volume low and play some song, if the sub starts working fine then it has to be some problem with the headunit's settings.

as for the wires, no it doesn't matter, not only does it not matter which of the 2 wires you use as postive, it doesn't even really matter whether you wire the sub's + to the amp's + or the sub's + to the amp's - ("backwards" so to speak). It would sound slightly different if you wired it up backwards, but nothing like what you're experiencing.



oops, I kinda made it seem like it mattered. sorry I didnt think to clarify that. But as a side note, for future reference, if you hook up multiple subs on separate channels, dont be careless because they should be wired the same way.

right, if you have multiple voice coils or multiple speakers you have to make sure you're consistent, but the actual polarity doesn't really matter, just as long as you keep it the same for everything.

I had it grounded to a metal part below my stereo, where my heater comes out... the same piece of metal my head unit is grounded to. I also have tried it bolted through the driver seat bolt... but that bolt isn't too clean.

I have one of those headphone to RCA cables... I could try that with a discman.

I have tried hooking up the sub to a 8 ohm home system and it was okay... well I had to crank it but it was decently bassy, for a home system hookup.

have u tried turning off your high pass filter and play it at a low volume (so as not to blow your other speakers) and see if the sub plays louder. Im thinkin the same thing SR20 is, which is that the HPF is killing any signal your sub might get.

The amp has a low pass filter... just an on and off switch, I have tried both and they both seem to be the same. I'll try again though.

How would I go about adjusting the high pass filter on the Clarion head unit?

By the way my head unit is the Clarion DX425.

Would improper grounding be the cause of not much power going to the sub? Or is it that if it's grounded at all then that's good enough?

bad grounds can cause a lot of different problems, it's worth a shot

Okay I tried hooking up an IRiver MP3 player with a wire coming out the headphone jack that splits into RCA cables and I hooked that up to my amp, and the sub did pound!

These are just regular home RCA cables... could my Wal-mart RCA cables be the whole problem? I have other home RCA cables I will try when I get my head unit back (it's getting warranty work done at A&B sound, it busted today).

The sub was pounding pretty nicely with gain at Normal - 60% and it had some high coming through it but when I flicked the Low Pass Filter on it sounded awesome... no speakers playing but it still pounded good!

The salesman at A&B sound said it was because my amp is so low powered. My Pioneer amp is 100W x 1 RMS with my MTX sub which is recommended 50 - 250W RMS, or my 150 W RMS Stage 1 RF... he said that with both of those subs I need a way more powerful amp. Obviously he's just trying to push his expensive product... but he was claiming that my problem was because of a low power amp... but it should still put out some power to the sub! I hope the problem is just shitty RCA cables. Could this be it?

I think it's your headunit, when you get it back from the warranty work the problem might be fixed (hopefully), if not you can try new rcas and see what happens. At least you know it's not the sub or amp

im just curious... how did you turn the amp on w/o the system remote signal coming from the head unit? And about the warranty work on your deck, hopefully they CANT fix it and they have to give you your money back, so you can buy a deck with a sub out put. That way you can still set your HPF w/o killing signal to your sub.

I hooked up the remote wire to a power wire. I kind of thought it would make sense and then I checked the amp instructions and it said to do that if the Head Unit doesn't have a remote output.

My head unit makes a ticking noise as if something is stuck in there, it won't play CD's. They'll probably just remove whatever is in there or fix it. Why would this particular head unit be filtering out low frequencies? It doesn't list HPF as a feature on the box or instructions...

My amp comes with a little square plug where you hook up 4 wires... pos and neg from left and right speaker... since I only have two speakers and my head unit is 50w x 4, could I hook this up incase my RCA cables are the problem? This is supposed to be for head units without RCA outputs, but is it as effective?

the instructions always say its just as effective, but Ive never tried it. I say hook it up.

Yeah hopefully when I get it back I can try that. I phoned today and added in the bad RCA plugs thing to the warranty work, I wonder if they're busted or just a High pass thing?

who knows, its too bad you didnt get a chance to hook the amp up to your mids before you shipped it out. That could have saved some time wondering. I really hope there was something wrong with your deck, because if not, then im not sure what to think next.

I did hook up my 6" speakers to my amp... one on each channel... and then one and the sub and all that. It sounded terrible... running the speakers straight off the deck was way better.