My sub box!

[I want a T5]

I thought I would share this beast with you ICE fans!

It's about 30" long by 12" square and house a pair of Sundown Audio 8" subs; small but incredibly powerful. 2

2 of these in a similar box have been measured to produce over 140dB. The subs are dual 4 ohm (thanks again to Santa for picking these up) and have the voice coils have been configured all in parallel to show the amp a 1 ohm load so they will both get 390 watts each!

I had the box designed by a guy in the US who does free designs using some pro box calculator and then set off to B&Q for them to cut the mdf (all 18mm).

Glued and screwed and then when the glue had set (I like to use Gorilla PU glue as it foams up and fills any minor gaps well), I removed all the screws and replaced with 40mm hardwood, 6mm dowels for added strength.

Corners and edges all trimmed and rounded over using a router.

Hope fully it will perform well and then I'll carpet it up in grey to match the interior.

[Peanut1]

hope i get a demo tomorrow!!!

[Brett855tdi]

Nice tidy box there, Ive not seen anyone use the dowels before.... have you seen it done with a sealed box? lol

[I want a T5]

Reason that I used dowels was that you can never be sure of a strong screw grip when fixing only into the core wood of mdf. This is due to the nature of the material as it is the core that is soft; the few millimeters from the surface is the most compact only.

Using a dowel with good glue simply increases the surface area of gluing used overal and is way stronger than a screw in this instance!

I have used the same method with another box I made which has a pair of 12" subs in a sealed box.

It doesnt make any difference to sound but will be better if you have a mishap and happen to drop the bu66er!

[Ed.]

Looking good. What frequency is it tuned to?

[I want a T5]

35Hz with a flat response but geared towards dance style music. It will still drop and pound though due to the design of the subs.

Problem with tuning a box is that the box itself may well be tuned but as soon as you put it in a car, the tuning can shift all over the place! It will probably be placed aiming at the back of the car, tucked behind the rear seats. Once its in, I can mess about with the volume and internal port length with some scraps of mdf I have left over.

Allways a bit of trial and error but one has to have a start point and this is it!

[frobes2]

Do you make sub boxes to order?!..

Thanks, Scott..

[Brett855tdi]

Ive been building made to order enclosures for nearly 10 years... well over 150 made for sure, currently a carpenter by trade building one off award winning exhibition stands (including speaker systems) But still doing the ICE in my spare time.... so i would like to think ive got some sort of clue.
I decided whilst reading this post on my lunch break i would put it to the test with one of 3 boxes i made last week.....
This is a box made from 23mm mdf (a grade) and at the time was held together with 34 2.5" screws:
http://s1146.photobucket.com/albums/...=VIDEO0013.mp4
thats a 10' drop, the 4 2" screws that held the woofer in gave way and the speaker smashed, magnets broke off (you can see the voice coil rolling around at the end) but yet the box was was still good enough to keep a seal, and had only ruffed the edge up a bit. i then took the carpet off the box and replaced the screws with 5mm dia hardwood dowel (not the same i know but closest i had)
http://s1146.photobucket.com/albums/...=VIDEO0015.mp4
the dowels cannot hold a compression and either snap or rip the mdf.
Wood vs Steel.... steel wins, i would recommend using some proper screws IMO

[I want a T5]

Do you make sub boxes to order?!..

Thanks, Scott..

I had to laugh there.......

I dont seem to have the time to make my own stuff but would always be happy to help you out of your are stuck.

I make hotel furniture for a living (on a large production scale in factories I run in the Far East) so have a very good working knowledge of wood etc. This though is a hobby. The design of boxes is quite a science, especially ported etc etc. With todays convenience of being able to go to B&Q and have them accurately cut your panles for you, its not outside of the realms of any handy man with a few of the right tools.

Happy to give any advice though and if you are close to Folkestone, you can drop in and look at what I do and have a coffee!

[I want a T5]

To Brett:

That is what I call proving a point bud!

I just hope I dont drop my box that far by accident!

Seriously though, that is an interesting test and one that I am going to pass on to my engineering team in the factory for their comments. Note tha tthe furniture I make is generally double dowelled and screwed and blocked so a belt and braces approach.

Thanks for taking the time Brett, I think I will go back to screws only! It goes to show how one can learn everyday!

[Santa]

Looks substantial mate :-) . (Though it has to be for those babies).

[I want a T5]

Ive been building made to order enclosures for nearly 10 years... well over 150 made for sure, currently a carpenter by trade building one off award winning exhibition stands (including speaker systems) But still doing the ICE in my spare time.... so i would like to think ive got some sort of clue.
I decided whilst reading this post on my lunch break i would put it to the test with one of 3 boxes i made last week.....
This is a box made from 23mm mdf (a grade) and at the time was held together with 34 2.5" screws:
http://s1146.photobucket.com/albums/...=VIDEO0013.mp4
thats a 10' drop, the 4 2" screws that held the woofer in gave way and the speaker smashed, magnets broke off (you can see the voice coil rolling around at the end) but yet the box was was still good enough to keep a seal, and had only ruffed the edge up a bit. i then took the carpet off the box and replaced the screws with 5mm dia hardwood dowel (not the same i know but closest i had)
http://s1146.photobucket.com/albums/...=VIDEO0015.mp4
the dowels cannot hold a compression and either snap or rip the mdf.
Wood vs Steel.... steel wins, i would recommend using some proper screws IMO

Brett!

I hope you don't mind, but I have copied this over to the talkaudio.co.uk I go on. I am sure there will be some interesting feed back.

Do you go on there?

[Brett855tdi]

Brett!

I hope you don't mind, but I have copied this over to the talkaudio.co.uk I go on. I am sure there will be some interesting feed back.

Do you go on there?

No i dont mind at all, its a little test ive done that i hope can help others, dowels are usually only used cosmically in furniture (they obviously look nicer than a PZ2 head) .... and nower days are 2mm thick to cover a screw hole anyways.....

[neil1983]

Tidy looking sub box mate, How does it sound?

[I want a T5]

No i dont mind at all, its a little test ive done that i hope can help others, dowels are usually only used cosmically in furniture (they obviously look nicer than a PZ2 head) .... and nower days are 2mm thick to cover a screw hole anyways.....

It does kinda look nicer!

Just bought 500 of these: http://www.ebay.co.uk/itm/2208801902...84.m1952.l2649

So will use these next time I think!

What glue do you prefer to use? I used Gorilla PU glue as I like the foaming up and gap filling properties although in the factory, we generally use PVA.

[I want a T5]

Tidy looking sub box mate, How does it sound?

Tested it in my nephew's audi yesterday with power coming from a Genesis Profile 5.

Didn't go mad as the amp wasnt too keen on only seeing 1ohm load but it is musical and has a good grip on the bass notes which is encouraging.

I hope to give it the beans later this week when I can get it in my car with a full 400 watts per speaker!

The extension on the subs is amazing for such a small driver (thats how far the cone will move back and forth for those not sure of what it means!) and a pair have been measured at over 140dB which is chuffin' loud!

[Brett855tdi]

Yes they do look loads better than screws, myself i would go with nice long screws 3.5" tops really, with a good deep pilot hole 75% the depth of the screw... the thinner the wood you use, use more screws to get rid of any flex, i use gorilla glue if i have it, really good stuff (as long as you dont get it on your hands lol) otherwise no more nails.... no nonsense grab adhesive is really good too!
however whilst building a box you really want to work hard for there to be no gaps, the wood is stronger than most glue... especially gorilla glue, it works great for joining but not for filling as its not very hard once set, more like sponge.
i recommend a bead of hard setting sealant around the inside of the box once finished (smooth it off with your finger after ) if your good.... you can make a box with no glue.... to test a good seal in a sealed box push the woofer in slowly, once released you want it to come back as slowly as possible, but a top job you will feel the pressure as no air will escape. ( i know we are talking ported comp style boxes here, but even they mustn't leak other than the port!)

I had a genesis 5 channel until recently, was a great amp.... but those monster 8s are a bit much for it, i used a c2 12" diamond on it and had to turn the gain down to keep it running.
Would love two of those 8s in my c70 rear shelf lol

[I want a T5]

Yes they do look loads better than screws, myself i would go with nice long screws 3.5" tops really, with a good deep pilot hole 75% the depth of the screw... the thinner the wood you use, use more screws to get rid of any flex, i use gorilla glue if i have it, really good stuff (as long as you dont get it on your hands lol) otherwise no more nails.... no nonsense grab adhesive is really good too!
however whilst building a box you really want to work hard for there to be no gaps, the wood is stronger than most glue... especially gorilla glue, it works great for joining but not for filling as its not very hard once set, more like sponge.
i recommend a bead of hard setting sealant around the inside of the box once finished (smooth it off with your finger after ) if your good.... you can make a box with no glue.... to test a good seal in a sealed box push the woofer in slowly, once released you want it to come back as slowly as possible, but a top job you will feel the pressure as no air will escape. ( i know we are talking ported comp style boxes here, but even they mustn't leak other than the port!)

I had a genesis 5 channel until recently, was a great amp.... but those monster 8s are a bit much for it, i used a c2 12" diamond on it and had to turn the gain down to keep it running.
Would love two of those 8s in my c70 rear shelf lol

Done the bead of seal before I put the lid on!

Definately agree re accurate cutting. I made the poor lad's life a misery at B&Q when I had the board cut up! He couldnt understand why I wanted a slice of the measuring edge as the board was actually 4mm out of square! I also get paranoid about moisture ingress on the exposed edges. Any cuts I do myself, normally with a jigsaw, are done with a fresh and sharp blade and long cuts are done against a guide clamped to the board and then done slowly to let the blade do the work. I had to cust some 45 degree angles for internal corner stregnthening/air guiding which was fun with a jigsaw! All done with 18mm of B&Q's finest!

I also like to scrub the flat surface of mdf with IPA and an old towel so as to remove the waxy releasing agent from when the boards are pressed prior to gluing up (I also scuff the surface with a coarse grit paper).

I also dampen both surfaces lightly with water prior to using the Gorilla as it helps set off the glue as well as making fibres stand up and give a bit more grab. Maybe a bit OCD but it takes a few minutes and it all helps.

I will be using the sub channel from a DLS A5 for these little beasts, 1 ohm will show the speakers around 400 watts each (there is a good power supply to the amp!) which is still shy of what they could take!

[Brett855tdi]

Done the bead of seal before I put the lid on!

Definately agree re accurate cutting. I made the poor lad's life a misery at B&Q when I had the board cut up! He couldnt understand why I wanted a slice of the measuring edge as the board was actually 4mm out of square! I also get paranoid about moisture ingress on the exposed edges. Any cuts I do myself, normally with a jigsaw, are done with a fresh and sharp blade and long cuts are done against a guide clamped to the board and then done slowly to let the blade do the work. I had to cust some 45 degree angles for internal corner stregnthening/air guiding which was fun with a jigsaw! All done with 18mm of B&Q's finest!

I also like to scrub the flat surface of mdf with IPA and an old towel so as to remove the waxy releasing agent from when the boards are pressed prior to gluing up (I also scuff the surface with a coarse grit paper).

I also dampen both surfaces lightly with water prior to using the Gorilla as it helps set off the glue as well as making fibres stand up and give a bit more grab. Maybe a bit OCD but it takes a few minutes and it all helps.

I will be using the sub channel from a DLS A5 for these little beasts, 1 ohm will show the speakers around 400 watts each (there is a good power supply to the amp!) which is still shy of what they could take!

Sound like good work to me! i also have an OCD like this lol and work in a similar way to yourself, its mainly down to my job as the final finish is essential, especially as im mainly aiming for the stand of the event with most of the stands i do (got 3 under my belt so far)

The DLS amp are brilliant, ive had a smaller one myself and its been thrashed for 7 years and is still going in a mates car now, i also fitted him the 4ch version of the A5 the A6? cant remember, top kit ... got it all running through a carputer we built for it.... a pc's output makes a descent cd player sound crap in comparison.

What sort of battery and cap setup are you going to be running?

Also any comments on the other forum?

[Brett855tdi]

which is still shy of what they could take!

I was going to say you could do with a bit more really, ive used one of these before and value for money was pretty impressive:

http://www.ebay.co.uk/itm/POWER-ACOU...ht_4334wt_1206

Would do those subs well but then you also have to think at 5f of caps and at least one large yellow top.... the cost can soon start adding up, 2awg wiring too