Buzzing from sub?, I'm getting an annoying buzz with my new custom sealed box Options

[Noahwhite2014]

So I made a sealed box that takes up the inside of the spare tire well and has a false floor baffle flush with the rear seats in the down position. The volume on the interior is around 2.85 cubic feet and there is cushion foam lining the floor pan in the back. The whole box is bolted down to the spare tire tie down hole and that is also the ground point I'm using for the amp. Here's a picture of it.

Looks great and sounds great, but at certain frequencies I get a buzz from my plastics in the back. I believe it's also buzzing the bumper and license plate bezel (not the license plate itself since it has a rubber "anti vibration" frame.

Anyone have a good way to quiet that crap down? Lol

[Box]

Sound insulation!

[Bitter]

Adding mass to the metal panels may reduce or alter audible resonances but it won't fix rattles by itself. For the plastic panels you need to keep them from hitting the each other and the metal body, I like to use adhesive felt. I buy it by the roll and wrap the wire harneses in it, edges of panels where they meet the metal body and each other. For the bumper you need to either tighten the clips or install some stainless nuts and bolts that you can really tighten up to stop any rattling.

[The_enD]

Read up!
http://www.sounddeadenershowdown.com/

[Noahwhite2014]

Thanks for the replies! I Forgot to mention I have dynamat lining my entire rear interior , my interior plastics I know is one issue since I can't get them attached properly for some reason. Im probably going to be picking up a parts car soon so I'll swap the entire interior plastics over and verify all clips are there. Anyone know if lining the plastic with a thin layer of insulation spray foam helps? If not I'll just get some felt and put it in between wherever metal and plastic contacts and plastic and plastic contacts. My bumper is really secure, but I'll double check again. I'm thinking a sponge between the license plate bezel and the car and between the bumper and the bezel should help a bunch!:)

Let me know what you guys think of that plan if it'll work or not all in all not including the parts car cost it'll probably be less than $20 since I have most of everything I need haha!

[Box]

You could use rubber insulation spray on all the back of all plastic pieces and use felt where they meet other plastic panels or metal.

[Jmk91]

I love the way you have that box set up. Looks amazing besides that boss amp... That's problem number 1. They are probably one of the worse audio brands along with power acoustic and fusion and all that stuff. I have a 12 ported tuned to 32hz I'm running 1000 RMS @ 2 ohms I hear the rattle as well. So I ripped out all the plastic in rear and everything went away. Its a trunk that no one sees so why not rip it all out. Easier and netter than listening to it rattle. But if your in the market for a better amp I'll sell you an alpine MRV-m500 its 300 RMS @ 4 ohms and 500 RMS @ 2 ohms. Actually its 524 @ 2 ohms according to birth sheet for 90$ shipped it sells for 130-150 new I just upgraded to a Rockford 1000.1 is all. Its all the vibration from the sub there isn't much you can do actually. My bass hits so hard it flexs the backseat plastic I can see it move haha. Oh well it doesn't make any noise at least.

[Box]

You forgot about Dual. Pyle is slightly better, but not really.

Also I noticed the enclosure is a little on the big side.

Maybe if you kids didn't want the tri-county area to hear you. 100-200W RMS is plenty.

[Jmk91]

Kicker is weird about box sizes. My kicker comp r could go from 1cf to 4cf box size haha. And 200 RMS on a sub?! I got that going to my door speakers alone lol.

[Noahwhite2014]

Lol yeah I just bought that amp because at the time they were out of amps at the bestbuy I work at (lol... So i just ordered that one for like $30 and next day shipping for an extra $13 on Amazon. I planned on getting a different one, but haven't gotten around to it since I'd rather spend the money on other things like new wheels, lowering springs, side skirts, and getting my windows tinted. I mean it works for now I figured with such low frequencies I woudlnt hear any interference/feedback like how you can on an amp and a guitar till you turn the treble down

Edit: we were also out of the comp r 12s so I settled for the comp s 12.

If anyone wants the plans for the box I made I can redo it all an post it. It cost like $60 total but keep in mind this is hawaii prices lol, mdf is like $40 for the 4x8 foot sheets and glue is nearly $10 a bottle. When I discovered liquid nails I realize I wasted a $10 bottle of wood glue lol

This post has been edited by Noahwhite2014: May 2, 2015 - 7:14 AM

[Bitter]

For all intents and purposes a sub amp is a sub amp, it's not like you're going to really hear any distortion. As long as it's set properly I doubt any of you could tell the difference between a Dual and a JL during a blind listening test. Where the higher end stuff shines is when it's being pushed hard, where you need better audio shaping, where you need more variability with configuration, where you need to run very low ohm loads, etc. For what he's doing that Dual amp is adequate and NOT causing rattles.

Wood glue and liquid nails are two different classes of adhesive. Wood glue is better for the box because it soaks into the MDF and creates a bond that's more than just the two edges pushed together, liquid nails is a surface adhesive which would be ideal for bonding the box to the sheet metal of the trunk floor. Use the right glue for the right job.

[Box]

Signal to noise ratio and frequency response yo. Of course I don't think Kicker is the pinnacle of audio quality either, but they put out a decent sound at a loud volume for a fair price. Same with Power Acoustik, my brother has one of their 12" subwoofers at the moment. If you want loud for cheap they're the way to go.

100-200W RMS is plenty when paired with 68-84W RMS or so of the rest of the system. Of course I don't listen to rap or other bass boosted/enhanced music.

[Bitter]

http://www.bossaudio.com/auto/car-audio-so...s-audio-r1100m/

It's fine for a sub amp as long as you're expecting realistic numbers from it, more like 200W at 4ohm and peak numbers are garbage. All the watts in the world matter not when your speakers can't use it well.

[Jmk91]

I know his amp isn't causing the real issue haha it was a joke
But I had a jl HD 1200.1 it puts.out 1200 RMS at 1-4 ohms if I recall correctly and I changed it out to a pioneer because I sold the HD 1200.1 on eBay and yes I could tell a huge huge difference in sound quality... the amp only amplifies the sound but how it does it makes a day and night difference. But who cares haha. You ever think that your box might be the issue? Your sub is firing up meaning the air pressure is bouncing off the bottom and basically off your trunk too.. This results in vibration to the entire rear end I'd think.. That would cause any plastic that attaches to rattle and make noise. You could switch out boxes to see.

[Box]

Amps colour the sound as well, but in these instances you want as accurate a reproduction as possible.

Anyhow, it takes twice the wattage for a 3db gain, and it takes a 10db gain for something to be twice as loud. So always keep that in mind when shopping for these kinds of things.

Also he brings up a good point, if the trunk well is acting as the back wall of your box anything in conjunction will vibrate a fair amount.

[Noahwhite2014]

After a little bit of testing at work with the car audio install guys we found out it's just my interior plastic, third brake light bar, and the license plate bezel. They took the bezel off and put the sponge I bought between it and the body and a majority of the rattles stopped. The rest is just interior panels that I have electrical taped down to stop annoying me until I get new panels with new clips that will hold it in place better lol. It sounds great now though!:) honestly I don't play the sub very loud at all it's just there so that I can hpf my speakers so they don't distort when I have the volume up.

Idk if I meant hpf or lpf... Whichever one cuts out the 125hz and lower frequencies for the speakers and sends that too the subwoofer

This post has been edited by Noahwhite2014: May 2, 2015 - 5:47 PM

[Box]

If it's cutting out low frequencies that'd make it highpass, though it'd be weird to do that with a sub since you know the sub is for bass frequencies.

[Jmk91]

Yeah I have mine set at 80 and lower go to sub anything above 80 your mid range should handle it not the subwoofer. It can don't get me wrong the sub can probably pick up 200hz but it just doesn't blend in as well and will sound horrible.

[Box]

Just depends on the woofer, most have a response of 20-200 hertz but there are those that go up to 500 hertz and more. Someone that listens to bass heavy music primarily will be fine with the lower response range, but someone that listens to a lot of rock music or other music that the bass doesn't sit near subsonic frequencies constantly something with a higher range would be more suitable.

This post has been edited by Box: May 2, 2015 - 10:12 PM

[Jmk91]

To an extend. The mid drives deliver more on 100+ hz. The sub really shines from 20-80. Almost all sub's can go to 150+ hz but if you want a sound system that's well blended in the cut off is best between 80-100.