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.

[Box]

Or be super OCD and run a 15" from 20-100, then a 10" or 8" from 101-250, but I like the entire bass range below middle C to there.

This post has been edited by Box: May 3, 2015 - 1:00 AM

[Box]

...

This post has been edited by Box: May 3, 2015 - 1:02 AM

[Jmk91]

Not really. 15 inch sub is useless unless you listen to rap/hip hop only. It has very poor response time. It can't hit double bass line punches that a 8,10,12 can hit in the same frequency.

[Box]

Not all 15's have terrible response, of course a 10" or the like will ultimately be quicker but it's not going to move as much air and won't reproduce lower frequencies as well. That's why you use both as smaller woofers take care of higher frequencies and the attack, and the larger woofers take care of the lower frequencies. Of course the crossovers aren't so clear cut, but you get the best of both worlds that way.

This post has been edited by Box: May 3, 2015 - 12:59 PM

[Jmk91]

Almost all 15s are horrible. I haven't seen one 15 sub that could keep up with bass line punch of five finger death punch. They all sound like one big blurrrr thru the song haha. They are made just for low hits not quick and steady hits. Also I've seen some sundown sa 8s destroy hahaha. For being 8s they produce more air than you'd think. I've seen an sa 8 shake the entire car harder than most single 12s.

[Box]

It's also a matter of enclosure, if it's not properly tuned for the woofer then you won't get optimum performance. That's any speaker though. The largest car audio sub I've used is 12" but in PA systems I use 15" woofers all the time and the good ones never have trouble keeping up with arpeggiated bass lines. One would think there'd be a 15" car sub as well that could keep up since in function car systems aren't too different from PA systems, and that's to accurately reproduce the sound.

This post has been edited by Box: May 3, 2015 - 5:48 PM

[Jmk91]

I've never seen in a car. I've been to many of comp meets and 15s are just for SPL and hip hop. PA systems mostly play easier music such as hip hop/country all that. Any harder metal like five finger death punch (not the radio bs they play), cradle of filth or anything deep no 15 I've ever seen can keep up with the punch. It does matter about box as you said. Maybe If you put a 15 in a custom sealed box that downfires it might sound alright but I still don't think it'd handle the intense bass lines. My 12 can hardly keep up.

[Box]

What do you think they use at concerts to project the music, a PA. Doesn't matter if it's rock, country, folk, or what have you. If it's larger than a few hundred people everyone will be through the PA.

Everything is mic'd up, run through a mixer board that costs more than the average car, and runs out to massive speaker and horn stacks.

Even smaller gigs will generally mic the drums and run out the house PA.

This post has been edited by Box: May 3, 2015 - 11:31 PM

[Box]

I like how this has completely ventured off from the original topic. Well, at least it's still in the same category.

[Jmk91]

Haha I guess we did. Oh well haha. I see what your saying but in car audio I've never heard a 15 or 18 that was able to not fall off with intense and quick bass line punches. Maybe pa systems use a bigger magnet or something.

[Box]

Just looked up the datasheet for the 15" in my cabinet and it has a range of like 20-2,000 hertz with a 99 db sensitivity, so that'd explain things. That and how it's constructed probably differs a little as well. I was thinking the ranges might've been different but why it didn't register at first I don't know, I blame no sleep over the last few days.

Well great mystery solved. I have a nice older 12" DVC Rockford Punch I need to get around to using, though it's a lot more than what I'd ever need as I think it was 500W a coil at 4 ohms.

[Jmk91]

500w or RMS? Wattage is nothing the RMS is what matters. 500 watt could be as low as 150 RMS. I know older Rockford stuff is all low Rms rating. Even the new Rockford stuff isn't even that high I think a p3 sub is under 800 RMS and its the best they offer besides power series ( way over priced and poorly perform )

[Box]

Even RMS can be sketchy unless it's CEA certified.

Just dug it back out of the music room and it is 500W RMS and 1,000W peak, and it's a USA made P3. So I guess that'd be 250W RMS 500W peak per coil. Either way it's way more than I'd ever use, which is why I've never gotten around to using it.

Oh, that's also at 4 ohms. So it'd be a little more running at 2 ohms I suppose.

[Jmk91]

I'm confused with your last statement. Most sub's are set X per sub not per coil and if your sub is rated to handle 300 RMS that's what its rated for. Doesn't matter if you run it at 2 ohms or 4 ohms it still requires same amount of rms. 4 ohms sounds better but also harder to push. Home system guys always go 8 ohms. My sub for an example is 1000 RMS. So I can run it 1/2/4 ohm and do 1k RMS but 4 ohms would sound the best but idk any amp that can push 1k RMS at 4 ohms that's not over 500$+ or run it at 2 ohms @ 1k. Never heard of a sub being rated RMS on different ohms.

It's amp that changed with RMS not sub. My alpine can do 300 RMS @ 4 and 500 RMS @2 its not 1 ohm stable. My Rockford 1000.1d can do 500@4 and 1k@2 ohms its not 1 ohm stable as well.

[Jmk91]

Also dvc and SVC are basically the same. Only difference is SVC can't be changed ohm load. If its SVC @2 ohms you can't make it 4 or 1 ohm. Dvc you have more wiring options. Ive seen people run power right to coil but I have no idea why someone would do that when the dvc was meant to be for wiring options

[Box]

PA cabinets can vary wattage with ohms, which I know it's two completely different things but my background in audio started with PA systems. Generally you'll have a nominal impedance usually at 8 ohms, then have the option of 16 ohms but at less power.

When I've used a 2-channel amp with a DVC to keep it at 4 ohms I'll do half the wattage per coil as to not exceed the total rating. So technically it's not divided per coil in the subwoofer itself, but you get the idea.

[Jmk91]

Ohhh okay I see

[Bitter]

The 6x9's in the back of my Mazda keep up with fast bass just fine and sound so good and natural down to around 40hz then start dropping off a little and are off totally around 15hz. Car sounds great, very natural not overly bass'd or anything. They're the tangband 6x9's from parts express. PE's got some GREAT speakers at great prices that do fantastic in cars even if they're not marketed for cars. Speaker is speaker, they don't care car or home as long as they're protected from direct sun and water.

[Jmk91]

Home audio is mostly rated at 8 ohms tho. So no amp your car CD player if its after market runs 11-24 RMS roughly. Using an 8 ohm speaker your hardly producing enough power to power them correctly I'd assume but if you say they sound good than there goes that lol. I use jl or nvx or alpine type R mostly. They all are good but require an amp to push them correctly. Most higher end audio isn't OEM or low RMS friendly. Alpine type r take 100+ RMS to function correctly or as they are designed too. Infinity and jbl are great low wattage replacements

[Bitter]

Hmm so how am I thumping away a pair of 6x9 8ohm Tang Band in the rear deck on my Mazda off a JL 300/2? Such blanket statements.
http://www.parts-express.com/tang-band-w69...woofer--264-837 Looky, 8 ohms. Thump thump thump no problem, just wire to a 4 ohm load. Rear fill, no care about stereo behind your head. (running them IB in the rear deck, they're seriously great speakers for the money and sound amazing after about 3-4 hours of play time once they soften up a little)

http://www.parts-express.com/cat/subwoofer...%28%29%2Frecord[endeca%3Amatches%28.%2C%22P_PortalID%22%2C%221%22%29+and+endeca%3Amatches%28.%2C%22P_Searchable%22%2C%221%22%29]&PortalID=1 4 ohms

http://www.parts-express.com/cat/subwoofer...%28%29%2Frecord[endeca%3Amatches%28.%2C%22P_PortalID%22%2C%221%22%29+and+endeca%3Amatches%28.%2C%22P_Searchable%22%2C%221%22%29]&PortalID=1 2+2 DVC

http://www.parts-express.com/cat/subwoofer...%28%29%2Frecord[endeca%3Amatches%28.%2C%22P_PortalID%22%2C%221%22%29+and+endeca%3Amatches%28.%2C%22P_Searchable%22%2C%221%22%29]&PortalID=1 1+1 DVC (crazy expensive and huge though, pay to play...literally)


Just about any of those speakers would be suited for use in a car, some more than others due to resonant freq and sealed or ported volume requirements. Speakers are speakers, as long as you can drive them and house them correctly you can play them.

This post has been edited by Bitter: May 5, 2015 - 9:42 PM

[Jmk91]

On your first post you never stated you had an amp running them. I was assuming you had them off a stock radio or a after market head unit. This is why I stated the RMS head units supply at 4 ohms. Anything will thump given the power to them. I was thinking how the hell are you thumping off 8 ohm speakers on a stock/after market head unit alone...

[Jmk91]

At first I was like how are you getting any thump from non amped. Thsys why I listed good non amped speaker replacements. Pioneer is so so same with Kenwood. Infinity/jbl are my personal favorite non amped drivers. Basically non amped them speakers.wouldn't work correctly. Its like trying to drive a dump truck on a 50 HP engine. Can it do it yes but effectly no.

[Bitter]

We're talking about subs, why on earth would anyone be talking about driving speakers with a head unit in a discussion about subs? That's like talking about fishing blue gill on a charter boat in the atlantic.

[Jmk91]

Bro you said 6x9... 6x9 isn't a real sub. Or at least I wouldn't count it as a sub. Its a 6x9 lol.. I guess I was confused I just now clicked your link I thought you where talking about a 2/3 way 6x9 not a 6x9 sub as a driver... That's why I said about RMS out put and all that. Also you said it cuts out at 15hz the specs say 35 is low as it goes.

This post has been edited by Jmk91: May 5, 2015 - 11:21 PM

[Bitter]

35hz is as low as it goes on paper in sealed or ported box, but IB runs much lower on less power. The pair easily rattles the whole back of the car if I want it to, even with only 7mm xmax. Srsly, you're a little out of your depth on this, just stick to kickers and boss amps.



Does that look like a normal 6x9? It's got a bigger magnet and voice coil than some 8" and 10" subs do. It'll handle 150W RMS all day every day without breaking a sweat. I

This post has been edited by Bitter: May 5, 2015 - 11:32 PM

[Jmk91]

Lol are you kidding me? I've been messing with car audio for years and years I've done at least 20 installs. I was confused on what you said I didn't click your link and had zero idea why you even brought up 6x9s.. I thought you where talking about a normal 6x9 speakee that wasnt a subwoofer driver.I've never heard of anyone even using 6x9 sub's in a car. So clearly I misread that doesn't mean I don't know what I'm talking about.