Hey guys, I'm new to car audio and just installed my first sub a few days ago. It's a 12 inch Dcon D4. I have it running at 2 ohms off of an audioque aq750. I built the enclosure using the optimal ported recommendation on the SSA website. The problem is I cant turn up the gain on the amp very much without the sub making a rattling noise. Any ideas what I might have done wrong to cause this? I know I'm not getting anywhere close to full potential out of this thing. With the gain set low enough to eliminate the rattle, the mirrors don't even move! The sound is very good, but there just isn't any power at all. All advice is greatly appreciated.

Pics of enclosure and materials used? Are you sure its sub noise and not the box itself?

The gain on the amp is to match voltage coming from the headunit only. If you are new at setting gains it I would say dont turn it over half way up and leave bass boost off.

Where do you have the LPF and SSF set on the amp?

I used 3/4 inch mdf board. I have the gain at about 10 o'clock, ssf at 10 o'clock, and gain at only 9 o'clock without the rattle. And I put my ear right up to the sub and it's coming from the sub.

And bass boost on zero

I used 3/4 inch mdf board. I have the gain at about 10 o'clock, ssf at 10 o'clock, and gain at only 9 o'clock without the rattle. And I put my ear right up to the sub and it's coming from the sub.

Sorry but that doesn't help. Does the amp have silk-screen printing saying 20hz, 30hz, 40hz, 50hz, etc? Approx where would you say the SSF and LPF are set, in hz?

Oh, sorry. The lpf is about 90-100. For the ssf it says it goes from 5V-0.15V, can you explain that to me?

Oh, sorry. The lpf is about 90-100. For the ssf it says it goes from 5V-0.15V, can you explain that to me?

The gain will be in voltage.

The SSF will be in hertz (hz). SSF is the subsonic filter, same as a high pass filter. IE: set to 30hz, attenuates frequencies below 30hz.

Yeah I understand that, I just don't understand how something can go from 5 up to 0.15? But anyways, do you have any ideas as to why I'm having this problem?

Yeah I understand that, I just don't understand how something can go from 5 up to 0.15? But anyways, do you have any ideas as to why I'm having this problem?

It can go from 5 down to 0.15 Doesn't matter what direction it goes on the knob.

You still haven't answered my original question as to where the SSF is set to.

The rattle could be from over-excursion caused by improper SSF setting. It could also be a wood panel on the enclosure rattling. You could also try lowering the LPF a bit.

You can also check your head-unit settings and make sure those are flat, and aren't providing any boost anywhere.

Well I guess I don't know how to set the ssf. I thought it would be at 30 or 32, but I don't know where to set it if it goes from 5-.15. And I don't think it's over excursion. The sub barely looks like it's moving. I'll check my head unit. Thanks for the help, I really appreciate it

Well I guess I don't know how to set the ssf. I thought it would be at 30 or 32, but I don't know where to set it if it goes from 5-.15. And I don't think it's over excursion. The sub barely looks like it's moving. I'll check my head unit. Thanks for the help, I really appreciate it

Seems I wasn't clear explaining it.

The gain setting will be in voltage, in your case: 5v - 0.15v

The SSF setting will be in hertz (hz), and it'll likely start around 10-20hz.

Wow, okay. I had the wrong mental image in my head. My ssf is 10-50. I have it set to 30 right now.

From here I would double check the wiring on the speaker terminals to the amp--otherwise I'm not sure what else to try.

Yeah I did that today... Could my box be the cause of this?

Yeah I did that today... Could my box be the cause of this?

If the driver isn't moving much than I would rule out the SSF being an issue. Next I would try lowering the LPF. After that double check wiring. After that, with the sub playing, you could gradually apply some pressure to the cone with your fingers, and see if the sound goes away. If so then something may be amiss on the driver.

First off rattling your mirrors has nothing to do with anything. Absolutely crap reference. You should really spend some more time explaining things if you want to truly solve your concern.

Something is loose if you hear a rattle. Uneven torquing down a driver in a non-alternating pattern or against an obstruction can cause a rattle. Pull it, look inside the box, verify the mounting surface and retorque it in an opposite alternating slow way. Recheck all your electrical connections and make sure they aren't half assed. If the rattle is still there turn it so it is BARELY rattling and push around on the enclosure to find out how to stop it. If it truly sounds like it is coming from the driver though are in the process of harming it. Then report back.

Voltage input is why it goes from 5v to .15v. Amplifier has it's gain set lower when there is a 5v input than when you have a .15v input. It's "low gain" to "high gain" labeled in voltage to help you know about where to start setting it.

Okay, thanks you for the advice. Rattling mirrors is a pretty ignorant example, it's just the first thing that popped into my head. Tomorrow I'll torque it in an alternating pattern and see if that helps. Also I had some trouble fitting the speaker wires in the terminals. The terminals were way to small to fit 2 wires in the same one, so I kind of had to shove them in there... Is there a better way to do this?

On the speaker terminals? You can trim the end of the speaker wire some.

I would check the grounds of your amplifier as well. I mean, really check it, as in, look under the terminal you used, sand it and the surface down to bare metal.

can we get the external enclosure measurements of your enclosure and also port measurements? when i first started building enclosures i had this happen to me once and i realized that i built my enclosure wrong.

I would check the grounds of your amplifier as well. I mean, really check it, as in, look under the terminal you used, sand it and the surface down to bare metal.

He needs to check EVERY connection just like the ground. Bare metal, strong contact, nothing loose, no wires poking from anything. Exactly what I meant although your clarification is good considering...

When building the box the port was suppose to be 2 inches wide all the way around, but somehow the corner pieces were only 1.5 or 1.75 inches apart. I can't remember for sure. That's the only part of the box that wasn't exactly like the specs. Could that be the reason for the rattling noise? It sounds like it's coming directly from the driver, but I'm new to this. I could very likely be wrong.

take the sub out of the box and hook it up and see if you still hear the noise.

Only way the enclosure if going to make noise is if something is in it or its falling apart.