# 2 questions: block inside sub box, and repairing screw holes for sub?



## 96jimmyslt (Jan 31, 2011)

I noticed a block inside the sub box I acquired in a trade.

Would this possibly hinder performance?

I am pretty sure this box was not made for this sub...

I was unable to get proper help from boss audio. They kept telling me to just use 4.1 for ported and 3.7 for sealed. Never gave me the actual .pdf for the sub.

1. proper way to remove it?

2. proper way to put it back in the event that it does more harm than good?

Here are some pictures of the block and a side view of the wall of the box off I made in paint.

Also, if anyone can tell me how to measure a box to find out the cubic footage, that would also be great. It seems to hit pretty damn hard, but not much more than what I had before.









Second question:

Is there a way to repair the screw holes for the sub? I've used wood screws and probably shouldn't have used the power screw driver.

I fear that every time I take the sub out, the screw holes get weaker and weaker.


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## nineball (Jan 17, 2008)

that piece looks to be there just as a support. 

you can drill out the holes and use any sort of fastener you like, or just rotate your sub a few degrees to get fresh wood to screw into.


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## spiralscratch (May 31, 2009)

It's probably just a brace to help strengthen the box. I can't imagine it would degrade performance. I wouldn't remove it.

Calculating gross volume is easy. Simply measure each dimension of the box, subtract out the width of the wood from each, and multiply the three together. If you want to get even more accurate, measure out the volume of the bracing, etc. inside the box. To get the net volume of the box, then subtract out the displacement of the sub itself.

One way to repair worn screw holes is to use CA (e.g., crazy glue). Use a thin wire, toothpick, etc. and dip an end into the CA. Run the tip along the inside surface of the screw hole, coating it completely. Let dry. The wood may soak up some of the CA, so another application or two might be needed (test a bit after each application). If this doesn't work out, you may have to drill out the holes and insert some t-nuts instead.


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## Gary S (Dec 11, 2007)

Yes, t-nuts would fix your screw hole problem. Parts Express used to have them, don't know if they still do.

I don't use screws for top-mount speakers anymore... I cut the carpet away frum under the speaker mounting flange so that the speaker mounts directly to the wood, and use a bead of removable weather stripping to mount the speaker, and let it cure/dry overnight.


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## 96jimmyslt (Jan 31, 2011)

Never thought to just rotate the sub a little 

I also forgot all about t-nuts...thanks for that suggestion!

Would 2 t-nuts on each side of the wood be ok? I am thinking of strength here...


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## nineball (Jan 17, 2008)

i forget the name but there is something better than t-nuts for mdf. someone will chime in with it but i know t-nuts and mdf usually separate over time.


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## jcollin76 (Oct 26, 2010)

I'd say after you rotate your sub, mark the mounting locations, remove the sub and drill them out for the t-nuts. 

Insert the nuts from inside the box with a little dab of glue. Put a washer on the bolts and tighten them down to get the nuts seated good. Remove your bolts. 

Give the glue time to cure then mount your sub with some form of foam or something to seal it. Should be plenty strong.

Also, you could fill the old mounting holes with some wood glue, to help give it some more strength.


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## jcollin76 (Oct 26, 2010)

nineball said:


> i forget the name but there is something better than t-nuts for mdf. someone will chime in with it but i know t-nuts and mdf usually separate over time.



Hurricane nuts maybe?


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## Gary S (Dec 11, 2007)

Look here:

http://www.parts-express.com/wizard...main&WebPage_ID=3&searchFilter=nuts&x=11&y=21


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## 9mmmac (Dec 14, 2010)

To fill in the holes, use golf tees and wood glue. Or toothpics and CA (crazy glue).


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## spiralscratch (May 31, 2009)

96jimmyslt said:


> Never thought to just rotate the sub a little
> 
> I also forgot all about t-nuts...thanks for that suggestion!
> 
> Would 2 t-nuts on each side of the wood be ok? I am thinking of strength here...


If you do rotate the sub be sure to seal up the old screw holes somehow.

I think that two t-nuts would be overkill. Also, you may have some difficulty getting the threads lined up properly.


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## sqshoestring (Jun 19, 2007)

A cheater way is make a new ring and cut in half, mount with a couple screws and glue so its inside the box. But you have to make sure the sub you have will still have plenty of breathing room through its basket. Then just use long screws to reach the new ring. Use ply, it holds screws a lot better even half inch works fairly well.


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## bfowler (Nov 25, 2009)

if you go the t nut route, get the hurricane nuts. despite their look, they work amazing


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## TrickyRicky (Apr 5, 2009)

I love the golf tee idea. But if you really want to fix your problem then SLAP another 1/2" or 5/8" sheet of MDF on the face. That would really help you feel more comfortable knowing your sub is screwed to a little over an inch of wood. The enclosure I bought for 60 bucks at Amazon had a two layers of 5/8", I dont worry about my subs coming loose or breaking the enclosure. Which has happen but thats another story.


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## kenn_chan (May 27, 2011)

If that drawing you posted is correct, and the volume you indicated is also correct than that is a brace that is needed to stop the box from flexing. leave it alone. If the builder of the box knew his job, then re calculated the volume of that brace in when he constructed the box. removing it would change the port tuning that was origially built into the box.

once again this is assuming that your drawing is accurate. 

the rest of the suggestions for the screw issues are good. I personnaly would go with the T-Nuts if there is enough room to properly insert them, if not golf tee's and wood glue.


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## nineball (Jan 17, 2008)

e-z lok inserts

Thread Inserts for Soft Wood by E-Z LOK


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## mattyjman (Aug 6, 2009)

^ this


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## papabearsc (Oct 2, 2010)

1/4"-20 Barbed Body Insert Nuts 50 Pcs.

These are the best ever


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

To figure box volume, you have to do some measurements... 

Internal measurements or external -1.5" of the box and port.. as well as the brace.. 

then you figure the overall box volume, minus the port volume.. for box volume.. 

Then you figure port volume for tuning frequency.. 

THEN you TRY and find a sub that will work in THAT specific ported box.. 

Have fun.. ported boxes aren't as forgiving as sealed boxes to flubbs.. you can still get away with winging it, but it's not right... 

Boxes SHOULD be built for the sub, around the subs specs... not so much a sub thrown into a box and "hoping for the best"... 

I know, you are just playing around though..


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## Gary S (Dec 11, 2007)

or, cover the port hole(s) with a piece of wood, and use a sub suitable for sealed boxes.

If it's not loud enough, get a bigger amp.


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## XtremeRevolution (Dec 3, 2010)

TrickyRicky said:


> I love the golf tee idea. But if you really want to fix your problem then SLAP another 1/2" or 5/8" sheet of MDF on the face. That would really help you feel more comfortable knowing your sub is screwed to a little over an inch of wood. The enclosure I bought for 60 bucks at Amazon had a two layers of 5/8", I dont worry about my subs coming loose or breaking the enclosure. Which has happen but thats another story.


Any box that breaks or falls apart is very, very horribly built. My 13 year old brother could build a box that would support the weight of your entire car.


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## 96jimmyslt (Jan 31, 2011)

Gary S said:


> If it's not loud enough, get a bigger amp.


The sub is apparently way over rated @ 1500 rms.

I have an 850w rms amp that is said to be under rated and it pushes the sub to it's limits even at half gain.

I had to turn the gain to 30-40 %

I'm pretty sure it's just a crappy sub (boss audio) but the sub and box were basically $30 and its the hardest out of all the subs I have, so I say it was worth it.

I was just expecting a LOT more from 1500w rms, 15", and a 4.1 cubic foot box.


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## TrickyRicky (Apr 5, 2009)

XtremeRevolution said:


> Any box that breaks or falls apart is very, very horribly built. My 13 year old brother could build a box that would support the weight of your entire car.


Totally agree with you (dont know about supporting a 3,000lb car though, am use to driving big bodies) lol.

That box was bought by my mother when I was younger and made for very very small 12's (by that I mean wattage wise) was made with plywood and I think it was 1/2. Then I installed a JL W6V2 when they first came out and BOOM the box splitted wide open.:laugh: I did it because of ignorance and I was too in a rush to install it instead of waiting and building the right box.


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## kenn_chan (May 27, 2011)

cancelled


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