Sub Box Const. [Archive] - RiverRacer.Net

Sotally Tober

02-10-2006, 03:14 PM

So I got my boxes built out of 3'4" MDF. They came out sweet. I glued all joints with gorilla glue and nailed with 18G finish nails. I then started screwing with S.S. screws. Are the screws needed? What a bitch. Drilling and countersinking. What are you guys doing? Going to carpet at the end.
I'm going to mount my subs through the fiberglass into the box. The box is completely enclosed. Should I glue the face of the box to the fiberglass? Or is bolting the sub through the glass to the box good enough? What knind of glue. Epoxy?
Thanks

Sotally Tober

02-10-2006, 04:14 PM

Thanks, I just thought without screws the constant vibration would disinigrate the box. I plan on using the screws for the actual subwoofer to hold the box through the glass. Then use aluminum angle to bolt it in spots that would not be seen in the cockpit. For structural support.
Thanks SWB, I should send you a rack of beer for all your help!

Havasu Hangin'

02-10-2006, 07:53 PM

I'm going to differ with Bob.
Air leaking will only sound bad if it whistles, but the performance of the sub will not be affected. I'd worry more about the box vibrating and rattling. MDF is easy to cut, and works well in a car, but doesn't like being in a boat.
I'd screw it and glue it (and hope you sell the boat before it comes apart).

Havasu Hangin'

02-10-2006, 10:18 PM

Ok, first, you're freaking nuts if you think a sealed enclosure won't sound bad if it leaks. We're not talking about leaking in the back of the box, we're talking about leaking around the woofer, create cancellation.
Second, the box is already glued and built. Adding screws to it would be as useful as adding hearts and glitter, it would look good and that's about all.
Sorry, HH is wrong on this.
Hey Bob...it's OK to disagree.
Leaking air does not cause cancellation. Some guys have even drilled holes in boxes to prove no ill sound effect. The only ill effects could be air whistling...but that can happen with a noisy port, too. Of course, I'm talking about small leaks...not vented enclosures.
The glue will only bond the surface of the MDF- screws will add more bonded surface area, which is needed since MDF has very poor structural properties (but decent sound properties because it has consistant density).
Boats beat the hell out of boxes...not just the sub.

Havasu Hangin'

02-11-2006, 08:18 AM

Screwing a box after it's glued does not make it stronger, period.
We'll have to disagree on the sealing. We install these exact boxes at least once a week in every Mastercraft we redo, I can tell you for a fact that you can tell immediately when one is not sealed properly.
Since MDF isn't as strong as say...marine grade plywood...then the glue holds, but the surface of the MDF cracks- then the box will rack itself apart. You will still have a nice bead of glue holding on the surface, but the box will be junk. Period.
Screws pull the box from inside the wood, which means that you don't have to rely on a thin area of bonding on the surface to hold the wood together. I guess it depends on whether you want the box to last many years, or just as long as it takes to leave a stereo shop.
In fact, I would never use MDF in a boat again...but I like my stuff to last longer than a couple years.
Small holes do not affect sound wave properties, but they can whistle. I'm not saying don't seal the sub, I'm just saying that air leaks do not affect sound waves.
If you don't believe me on the sealing, try this:
Take two identical boxes and subs...and hook them to an amp in stereo. Drill a couple holes in one box, and cover them up. Then, have a couple impartial people try to hear the difference- you will be amazed.
You can always plus the holes after you are done, so the box isn't ruined.

Havasu Hangin'

02-11-2006, 10:22 AM

There's a big difference between drilling some small pinholes and not sealing the sub to the surface of it's enclosure. A big, huge difference. The latter will sound like shit.
Maybe what you are talking about is the sub vibrating against the box. Yes, that will create noise, but it is not from the accoustics changing because the box isn't sealed.
I've personally seen boxes come apart in boats. Nails and glue alone don't work well with MDF. In fact, screws don't work well in MDF, but it's better than just glue.

Havasu Hangin'

02-11-2006, 04:33 PM

I think most professional woodworkers will tell you, glue is what holds what together, not screws. Screws provide an excellent clamping mechanism during curing, but then again, so do clamps. We obviously have different methods. Roundabout, my dad was a professional woodworker. It wasn't what he did, but his job required that he construct wood enclosures from particle board. He built guitar amplifiers for Fender and Mesa Boogie. I can remember amps coming back for repair, they had been dropped by roadies or smashed with a guitar. The entire thing was destroyed, except for the glue seam.
In any case, screwing AFTER the glue has dried will not do anything. You fail to address that point, even though I keep pointing it out. His box is built, putting screws in it now will only do one thing, make Havasu Hangin' feel better. :D
I think you are missing my point. MDF in a boat is not strong enough to be held together by glue alone. The glue (and the surface it mounted to) will remain intact, while the area adjacent to the glued area comes apart. If you have screws in there, it provides clamping force (from inside the wood) that will slow it.
How fast a box comes apart also depends on how the box and sub are mounted. If the sub is horizontal, or the box is bolted to a vertical surface without support on the bottom, every wake you hit makes that heavy magnet try to rack the box. That's why MDF works in cars, but not in boats.
Using MDF, and not putting screws in MDF will only make a stereo shop more money when they have to build another to replace the one that's coming apart (which makes Bob happy).

Brian

02-11-2006, 07:29 PM

So I'm no expert but since these guys can't seem to agree... Here's what I did. I took the existing rear seat base that is built out of plywood, and reinforced and boxed in the subs with more 3/4" marine ply. I used a few screws to hold things in place while I epoxied the hell out of everything and made darn sure they were sealed and totally bomb-proof. MDF may sound better but in a boat I just didn't want to take a chance on the stuff disintegrating if it gets wet or beat up. Sounds great to me...
:)

Havasu Hangin'

02-11-2006, 07:38 PM

You do know that WFS does every Eliminator that leaves the compound? When we start having problems with the hundreds of boxes we've built, we'll go to a different construction method, until then, it's 1.5" air nails and glue.
I guess that would explain why I had to rebuild the boxes in my buddy's 28' Eagle...seriously.
MDF just sucks for boats. All the good builders use marine ply (but don't use that Kicker crap, either).

Havasu Hangin'

02-11-2006, 08:41 PM

Are you just purposely being contrary? I never thought you'd stoop to insulting our shop without some proof that WFS actually did the work in question...seriously.
That's in really poor taste, especially for a "moderator."
I had to replace the boxes in an Eliminator, that is a fact. I would expect anyone who wants to make quality boat boxes will not use glued MDF...but that's my opinion.
Are you insulting my box-making ability? I think that is in poor taste.

OutCole'd

02-11-2006, 08:43 PM

This is a great thread, I have leard MDF is good, Screws are bad, MDF is Mad, Glue is good, MDF is good, Screws with MDF are bad, Screws, nails glues and MDF are bad, bud MDF & glue is good but you need screws. MDF with any holes and glue is bad, unless you use screws. :cry: :cry:

Brian

02-11-2006, 08:50 PM

OutCole'd

02-11-2006, 08:51 PM

What do you know, you drive a Camry.
:D
Excuse me, it's an Accord, get it right Reaper.

Brian

02-11-2006, 09:09 PM

"Reaper", LMAO!
:D

Havasu Hangin'

02-11-2006, 10:26 PM

We're trying to have a serious thread.
Please move along...there's nothing to see here.
:D

Havasu Hangin'

02-12-2006, 07:48 AM

Never insulted your box making ability. Saying one way is good does not imply that another way is bad. You specifically said using MDF is bad and "good" builders only use plywood.
Yes...and that is my opinion. I also think that RF does not belong in a boat, Kicker sounds like crap, and 6 volts belong in golf carts.
Are you saying that I am not entitled to my opinion? If so, I think that is in poor taste.

Jordy

02-12-2006, 08:11 AM

until then, it's 1.5" air nails and glue.
I thought glue was enough??? Now I'm confused... :idea: :notam:

Jordy

02-12-2006, 10:14 AM

screwing a box after the glue has dried is like closing the barn door after the horses have escaped.
What kind of kinky shit are you guys into at WFS??? Screwing boxes and horses??? :D :D :D
When Adam and crew built my box in my truck they glued and nailed it. No screwing allowed. :D

OutCole'd

02-12-2006, 10:35 AM

"Reaper", LMAO!
:D
:D :cool:

Havasu Hangin'

02-12-2006, 11:51 AM

You know how we do it. :D
You guys could probably save a little more money by using paste and rubber bands..

Havasu Hangin'

02-12-2006, 03:20 PM

Now you're just being hurtful. :D
Naw...otherwise I would have said something like "...cardboard, paste, and rubber bands."
But that's not my style.
:D

Tom Brown

02-12-2006, 03:21 PM

Air leaking will only sound bad if it whistles, but the performance of the sub will not be affected.
I really, really, really hate to do this but I'm going to agree with ShockwaveBob and disagree with HH. :(
Air leaks, even small ones, will absolutely kill the performance of a bass reflex enclosure and dramatically reduce the performance of an acoustic suspension enclosure. It's more than just noticeable. It's dramatic.
BTW, the best way to seal a sub to an enclosure is with plumber's putty. You roll it up like a rope, put it on, and squish the driver into it. Just peel off the excess and it's clean and sealed perfectly. Silicone is shit to work with and seals poorly, by comparison.
Did I mention how much posting this pains me? :(

Havasu Hangin'

02-12-2006, 03:33 PM

Air leaks, even small ones, will absolutely kill the performance of a bass reflex enclosure and dramatically reduce the performance of an acoustic suspension enclosure. It's more than just noticeable. It's dramatic.
I'll will bet you $20 Canadian ($1 American) that if you take two identical boxes, with the same sub and same amp, you will be able to tell the difference with a couple small holes drilled in one.
Now, I'm sure there are thresholds, probably depending on the size of the leak, internal volume, and sub design.
Air leaks affecting sub response have been an old wives tale around the industry for many years, so we tried it, and nobody could tell the difference. It's easy to do- just plug the hole with a dowel after you are done.

Havasu Hangin'

02-12-2006, 03:46 PM

.. posting really sucks when we r dealing with a bunch people who dont do stereos think thy know it allllllllllllllllll!!! we can all learn from eachother. WFS!!!
I used to build stereos, but I wanted to go somewhere in life, so I moved up and became a Wal-Mart greeter.
:D

Havasu Hangin'

02-12-2006, 04:04 PM

i new that was u at the front door at the local wallmart :rolleyes:
Yes. No matter how many times I tell them, those damn Wal-Mart shoppers don't use Marine Ply, either.
:D

Tom Brown

02-12-2006, 07:23 PM

Air leaks affecting sub response have been an old wives tale around the industry for many years, so we tried it, and nobody could tell the difference.
I've tried it too, but with different results. A Nexus analyser was used to compare before and after. I don't have plots but perhaps one day I will grab a couple of old boxes and do a before/after comparison.
With a bass reflex enclosure, we were off 14 dB. With an acoustic suspension enclosure, we were only off a few dB and the curve was changed a little bit.
Perhaps with the sealed box, it wouldn't be a big deal in the grand scheme of car audio but I wouldn't want my box to leak.
Think of the cost to double the power to gain back 3 dB. How hard is it to use some care and seal the box? :idea:
With bass reflex, you can pretty much completely kill the output with a 3/16" drill bit.

Havasu Hangin'

02-12-2006, 07:34 PM

Perhaps with the sealed box, it wouldn't be a big deal in the grand scheme of car audio but I wouldn't want my box to leak.
I don't think the point was to build leaky boxes- only that small leaks won't matter in most car audio sub enclosures.
Here's another experiment. Take the same two boxes, but take 10% out of the volume on one by putting a piece of a 2" x 4" in there. See if you can tell the difference.

Jordy

02-13-2006, 07:38 AM

I wouldn't want my box to leak.
See a doctor and get it cleared up. ;)

rivercrazy

02-13-2006, 08:47 AM

There really is no significant difference in sound quality between 3/4" Marine plywood and 3/4" MDF. Why risk using such a structurally weak material like MDF in a wet environment? And an environment that subjects the box to the pounding a boat takes in rough water.
Oh that's right - its cost...........

phebus

02-13-2006, 08:56 AM

Oh that's right - its cost...........
Yea, we wouldn't want to invest an extra $30.- in materials on a $100k boat. :crossx:

Havasu Hangin'

02-13-2006, 10:30 AM

Yea, we wouldn't want to invest an extra $30.- in materials on a $100k boat. :crossx:
Are you guys being sarcastic?
If so, I think that is in poor taste.
:notam:

rivercrazy

02-13-2006, 10:32 AM

Are you guys being sarcastic?
If so, I think that is in poor taste.
:notam:
Sarcasm plus sarcasm is in poor taste. Damn internet wire jockey!

ROZ

02-13-2006, 10:33 AM

Are you guys being sarcastic?
If so, I think that is in poor taste.
:notam:
Atleast you guys have taste.. I have none ....

riverbound

02-13-2006, 10:44 AM

You do know that WFS does every Eliminator that leaves the compound? When we start having problems with the hundreds of boxes we've built, we'll go to a different construction method, until then, it's 1.5" air nails and glue.
Not EVERY Eliminator.....just most of them ;)
But we use the same construction method listed above and have had no problems. I have NEVER needed to do a Glued an screwed Box. Glue and nails work well and as long as the MDF doesnt get wet you will NEVER have any problems.
I had this same argument with a customer once.....proved my point by driving my truck over the boxes I built.....and they didnt break ;)

riverbound

02-13-2006, 10:48 AM

Yes...and that is my opinion. I also think that RF does not belong in a boat, Kicker sounds like crap, and 6 volts belong in golf carts.
Are you saying that I am not entitled to my opinion? If so, I think that is in poor taste.
I mostly agree with your opinion ;)
RF for Life :D :D

Havasu Hangin'

02-13-2006, 11:17 AM

Not EVERY Eliminator.....just most of them ;)
So you're the guy who built the Eliminator box that fell apart? :supp:
I'm confused...now we have two shops taking credit for building self-destructing boxes?
:idea:

rivercrazy

02-13-2006, 11:37 AM

So you're the guy who built the Eliminator box that fell apart? :supp:
I'm confused...now we have two shops taking credit for building self-destructing boxes?
:idea:
Well if you run RF amps I guess you don't need to worry about MDF boxes self destructing! J/K RB....:D

riverbound

02-13-2006, 11:47 AM

So you're the guy who built the Eliminator box that fell apart? :supp:
I'm confused...now we have two shops taking credit for building self-destructing boxes?
:idea:
Nope.... :) We LIFETIME warranty EVERYthing we build. I havent had a box "self destruct" yet ;)
The Eliminators we did, were by customer choice. They didnt like the sound of the "factory" installed Kicker Crap..... I mean stuff. So they decided to have the stereo done by a shop....not a guy in a van ;)
No offense to Adam....he turns out some really good work. but the stuff I have seen roll out of Eliminator is definitely subpar from what his customer would normally expect.

Havasu Hangin'

02-13-2006, 11:58 AM

Well if you run RF amps I guess you don't need to worry about MDF boxes self destructing! J/K RB....:D
Maybe the amps got so hot, it caught the MDF on fire? :supp:
....he turns out some really good work. but the stuff I have seen roll out of Eliminator is definitely subpar from what his customer would normally expect.
Does Kraco make square subs? :confused:

rivercrazy

02-13-2006, 04:26 PM

Just put a kicker sub in an MDF box with a Rockford Fosgate amp directly on the box. See what fails first. The screws, glue, amplifer, or sub. Or will the RF amp catch the box on fire before it falls apart! LOL!

Havasu Hangin'

02-13-2006, 04:38 PM

I'm betting the RF would get so hot, it would melt the glue, causing it to catch the woofer, carpet and box on fire. :D
But could that actually make the Kicker sub sound worse? :idea:

OutCole'd

02-13-2006, 04:47 PM

Now you guys have got Adam pissed, he's typing with two fingers on each hand. ;)
Does he type with an accent?

ROZ

02-14-2006, 11:43 AM

Does he type with an accent?
Sounds like he's pulling a double shocker on his keyboard...lmao!!!
The plain truth is that there is a time when you just can't satisfy a customer no matter what shop you are. All you can do is try to provide the best labor, product, and customer service you can. At some point any shop will make a customer upset. That's a given... It's part of business.
As far as shops bagging on other shop's work, there are many ways to skin a cat. There is more than one process to install a stereo system correctly. I hear people gripe about so-in-so doing something wrong, and it should have been done like this, when in fact it was just done diferently.
As far as lifetime labor guarantee, I think you set yourself up for failure unless you have the limitations completely outlined or highlighted and expressed to the customer at the time of pickup. Last thing you need is a Costco Warranty when the product has not been used under what's considered normal use and is abused..
just my .02

ROZ

02-14-2006, 11:45 AM

But could that actually make the Kicker sub sound worse? :idea:
The guy wuld be in real trouble if he didn't use 1 5/8 screws as well as the glue to hold it together.. :D

ROZ

02-14-2006, 11:50 AM

No offense to Adam....he turns out some really good work. but the stuff I have seen roll out of Eliminator is definitely subpar from what his customer would normally expect.
Transonic still does installs for Eliminator as well....
As far a I know the only "exclusive" 12v shop to boat mfg is Mark's Autosound and Hallett....

Havasu Hangin'

02-14-2006, 04:24 PM

We have a crew that is physically at Eliminator 5 days a week, so I'm not sure how jobs are escaping. ;)
You guys can't seem to seal a box...what makes you think you can seal the Eliminator shop?
:D

ROZ

02-14-2006, 04:31 PM

You guys can't seem to seal a box...what makes you think you can seal the Eliminator shop?
:D
Got to admit SWB, That's pretty funny LMAO....
Didn't know you guys had a crew over there... Guess my info was a little dated..lol How long you guys been there? I'm sure they let boats go there if the customer requests it, though...

Phat Matt

02-14-2006, 07:41 PM

You guys can't seem to seal a box...what makes you think you can seal the Eliminator shop?
:D
lol. That is a pretty good one. :D

Havasu Hangin'

02-14-2006, 08:35 PM

ADAM speaking here, i did not have a problem sealing your old laddy :crossx: :cry: :)
Look...just because you gay Irish guys are into the "laddies"... http://www.highperformancecars.com/hhangin/gay.gif
...doesn't mean us straight guys go that way.
:notam:
PS- No wonder you guys at WFS have so many problems with boxes:
1. You need at least a third grade education to calculate volume.
2. Gay guys probably don't even know what a "box" is.

rivercrazy

02-14-2006, 08:38 PM

You forgot the last one HH.
Kicker sucks!

Havasu Hangin'

02-14-2006, 08:49 PM

You're straight? Does you boyfriend know? :D
Ohhh...that's whitty? What's next from the third grade contingent?
"I am paper, you are glue..."?
:notam:
Oh wait...that's what you make your sub boxes out of...nevermind.

Havasu Hangin'

02-14-2006, 08:55 PM

I think the reputation of the shop speaks for itself.
http://www.highperformancecars.com/hhangin/gaydar.gif
:supp:

Havasu Hangin'

02-14-2006, 08:57 PM

They had to use "Gaydar" because "Havasu Hangin'dar" was too long. :D
http://www.highperformancecars.com/hhangin/smartchart.jpg

Havasu Hangin'

02-14-2006, 09:01 PM

Look at Havasu Hangin', all like, "Whoa, they have pictures on the internet now!!!!!!" and shit.
I just figured you third-graders liked pictures.
http://www.highperformancecars.com/hhangin/pimpslap.gif

Sotally Tober

02-14-2006, 09:03 PM

Man has this thread has moved. I've been gone for a couple of days and look what happens. Boxes are in and subs mounted. I glued, nailed and screwed them. What a lot of work. It is MDF though. I'll see how they last. I did put 2 coats of resin on them. After the glass work I wish you could see all the work. But I covered them with carpet to look "factory". They are in a very dry part of the boat. I do not understand how these boxes are getting water on them when they are inside a fiberglass compartment of the boat. I do understand water is a killer on MDF. If I have to rebuild I will do it with CDX. Pulling wire tommorrow. I spent $900 in just wire today. 0 guage wire aint cheap!! RCA wires, dist. blocks, fuse holders, etc. Running all my speaker wire in 12 guage. Just waiting for my amps to arrive.
HH whats up with Kicker being crap. Ive heard that from you before but never stated why.

rivercrazy

02-14-2006, 09:06 PM

For your next install, try welding cable. Its much cheaper than 1/0 gauge amplifer cable. And just as effective

Havasu Hangin'

02-14-2006, 09:09 PM

I glued, nailed and screwed them.
You are a smart man...I don't care what Shockwierdbob says about you.
(and he says it ALOT)
HH whats up with Kicker being crap. Ive heard that from you before but never stated why.
I think they are loud, but muddy- it's just personal preference. Maybe I'm getting old, but now I like my music to actually sound like music.