new mono amp
 

my amp is a mono block, but has 2 sets of speaker terminals. so i wired my 2 rockfords in parallel and only used one set of speaker terminals, pretending the other set just didnt exist i guess. well now the subs arent as loud or as clear as they were before. with my other amp, a 2 channel, the person who owned it last had it wired like the diagram below. is that wired in parallel? because the specs on my old amp doesnt show how many watts it is 2-ohms bridged. this amp is supposed to be 300 wattsx1 at 2 ohms and my old one only specified 250 watts x 1 at 4 ohms bridged

Um I don't think that can be a mono block with two set of terminals, I would bet good money that's a 2ch. What is the brand and model name? I'm having trouble really understanding what your saying, but I'm pretty stoned too.

I'm going to have no know for sure how many ohms your subs are, and the model name of your amp.

the amp is an infinity reference ref1300a and the subs are 4ohms. the 2 terminals really confuse me too, but they claim "there are two sets of terminals to make it easy to connect multiple woofers"

Ok after looking up the manual for the amp (If haven't done so already CLICK HERE). Yes those are just multiple terminals on a mono block, never seen that before. Since your subs are 4 ohms it's as simple as wiring a sub to each terminal, and your good to go.

and that will give a 2 ohm load?

Yes it will be 2 ohms

well after being completely baffled by why that new amp wouldnt work, i put the old amp back in and wired it like it was before i took it out. but now the subs still make that annoying "pop" instead of a "boom". why is this happening?

What do you mean pop? What do you have the crossover set to? Maybe it's too high. I hope the suspension isn't busted. I'm not even sure what a sub with a busted suspension sounds like, but I would imagine it would sound like a pop from bottoming out.

How did the infinity amp not work? Wasn't it working before? You may have damaged it running it like you did, but I don't think you did. I'm really unsure about this one man.

its so hard to explain the sound but its almost like a rattle inside the box.
i took the sub out of the box and when i saw the serial number, it turns out they are 8ohm subs as opposed to the 4ohms the person i bought it from said it was, which explains alot. so the infinity amp was underpowering at 4 ohms. i just dont know why its still "popping" now that ive hooked it all back up to how it was before =\

If it sounds like your box, then it may be a lose panel. Make sure you box has no leaks or loose panels. I'm really not going to be able to give good advice on this as I've never had a sub blow on me, so I can't say I know what it would sound like. Chances are it's your box or amp setting, make sure you have the crossover set to low pass, and they are not crossed any higher than 80hz.

yeah the crossover is set exactly at 80hz.
what causes a sub to bottom out? it wouldve had to have happened when i tried to hook the infinity amp up to it, cause they were fine before that

A box that is severely leaking can cause a sub to bottom out and damage the suspension, or overpowering but you haven't done that. Try turning you crossover down, somewhere between 60hz and 70hz. Where you cross it really depends on your music and listen style. I have a feeling that your box is leaking, and your subs are fine. If the suspension was damaged the sub would be drawn back into the magnet, you would notice it. Unless the suspension can be damaged without destroying it, that I'm unsure of.

If you want to fix a leaking box, take the subs out and run a bead of 100% silicone caulk or liquid nails along the seams and press it in with your fingers and allow it to cure 24 hours before putting the subs back in.

Cut the carpet where the sub gasket contacts the MDF, so it's just straight rubber -> MDF, not rubber -> carpet -> MDF.

Redrill the sub mounting holes and use new screws to get the seal tight again, overtorqued screw will cause the MDF to strip out and loosen up. A 1/8" or 3/32" drill bit and some 1-5/8" square drive decking screws in the matte black finish are awesome.

EDIT: By redrill the holes, I mean turn the sub so the new mounting holes will be "in the middle" of the original holes. Properly turning the sub will allow you to reseat the sub tight again at least 4, and probably up to 8x before the MDF is all used up.

EDIT 2: QLogic and prefabbed boxes are not sealed with caulk. That is another area they skimp on besides using staples instead of screws.

Very good advice, I usually don't think about those things as they just seem to be common sense to me, but very well said Brandon.

Thanks.

Also I would add liquid nails to the back of each hole that is not going to be used anymore, not really necessary but a nice precaution. Don't do it on the front as you need a smooth and even surface for the sub gasket to seal properly.

thanks ya'll. i guess it could be leaking from where i unscrewed the amp, but it shouldve sealed up when i mounted it back on, right?
i do hope its just a leak

Small holes like that isn't enough to damage your sub right away, but it will take away from the sound. I like to put a little silicon on all the screws I drive into the box.

So you bought some subs from somebody that didnt know they were 8 ohm?? Do they even make 8 ohm car audio subs?

Where did you buy them from and were they working fine before? Im thinking youve got some defective subs.

yeah theyve been working great for a few months now. this only started when i tried them with another amp and didnt like it because the popping sound started. so i hooked it up to the original and the popping continued

Sounds like the amp you tried was clipping and damaged the suspension then. Or you had a bit of a combination of clipping and leaking and damaged the suspension. Does the popping almost sound metallic?

yes, almost like a rattle

Take them out of the box and listen to them free air and see if the sound remains. If so its possible that like Toofatt said, youve damaged the suspension somwhow.

the rattling sound was not present when i took the subs out of the box. does that mean its definitely a box leak?

Yeah its definitely something to do with the box and Im almost certain its not the sub. If it was a problem with the suspension it would be bottoming out easier when outside the box.

So I do think it is a problem with the box but I doubt its a leak. A leak would generally just act like an improperly tuned port and at worse youd get some port noise but I kinda doubt it. My guess actually would be the box itself is rattling somehow maybe by improper construction or something. My specialty is in tuning and speakers so Im not that well versed in box design and such but I would check the box to make sure it was put together properly and nothing is coming loose anywhere. Better yet, slap together another box and see if that one has the same problem.

What kind of box is it? Is is a dual sealed? If so the center panel in a cheaper constructed box likes to come loose and resonate. If you didn't build the box yourself, I would just trash it and build your own. These prefab boxes use staples and cheap adhesives. If they used the adhesive I used you can get away with staples, but I used screws as well. If you a table saw then building a box will be simple and come outer perfectly. You can use any saw really, but a table saw would make perfect cuts. I can set you up with a few good links on building tips if your interested.

Just trying to fix this box is only a temporary fix. Assuming its the panel in the center, your not going to really be able to get any adhesive in and around the edges enough so it will glue strongly. And the screws you put in will only hold for so long. Vibrations and screws in wood do not mix well. Building a box is simple, and even easier if you have a friend or someone to help.

yea its dual sealed pre-fab. the divider board doesnt budge at all. but i guess even the smallest movement will cause big noise

how much does the mdf and carpeting usually cost? i just got a ticket so now im on a tight budget until i know how much the ticket will cost me

Well under $50 you can get everything with material to spare with mistakes. Bang on all the panels, they should be sturdy as can be. Don't just knock on them give them a good bang. You can tell from the sound of hitting it.

2 weeks ago, it cost me $45 to build my 3/4" dual 12 MDF box without the carpet and I'm 8 screws shy. I used a sheet of 3/4" MDF, a 100 box of #8x1.25" screws and 2 tubes of liquid nails max strength.