Jump to content

Troyus_

WA want to build two HT subs -need parts

Recommended Posts

Hello

Ive found some 15 inch drivers at a great price but I dont have specs for them. Anyway I want to build 2x sealed, dual opposed subs about 6-8 cubic feet each sub.

1 I want to be 600x600x600 MDF 25mm etc -Ill use this next to my two couches and it can be like a table there.

1 I want to be a tube sub (sonotube) about 450mm x 1m long in the opposite corner.

 

I cant find sonotube anywhere here (WA) like USA seems to have. Its everywhere there. Anyone know where I can get it here or something else that does the same thing?

As for the square sub, Ive been quoted $350 to design and cut (plus materials) or $750 to assemble a bare box for the subs. -anyway I can get this price way down on the sub box? Id rather not try to cut this myself tho as its a bit beyond me, a CNC would be good.

 

WA help :)

Share this post


Link to post
Share on other sites

You'll either need to google the T/S parameters or measure them before you can do much else. Box volume will be determined by the relevant T/S and you just can't state you're going to build it some random set of dimensions if you expect decent performance.

 

What are the drivers?

 

Sonotube is a brand name. Formatube is the local equivalent, but you usually need to order in a  full length and cut it yourself, so expect wasteage unless you have a relo/friend in the concreting industry.

 

Here is Collo's Sonosub guide. Scroll down and read the FAQ etc too.

Share this post


Link to post
Share on other sites

Thank you for your reply

(I have gone back to uni (5 years in :( )so I am trying to save money rather than buy a PSA sub. I think I could build 2 for the price of one there, even tho the 30f se on special).

 

Background - I want to build 2x 2x15inch opposed, sealed subs for my home theater (lounge room really).

I think these will be easiest over ported, especially as I don't have all (any) the specs I want. A sonotube one will fit nicely in the corner and a square one will fit in between my couches. Thats about the only spaces I have to fit these things.

 

Drivers seem to be really expensive here in Australia but I found some on clearance at deephz audio which seem a steal. They are ex PSA drivers as used in the XS30 so they should be decent drivers. The downside is that there are no  specs available for them. I have contacted Peter at deephz and he does not have the details and Tom at PSA wont give them to me. He says as they have never been sold separately he does not want to give out internal figures. That sucks but I can understand the position.

 

So all I have to go on is the dimensions of the PSA subs which had these drivers in, the XS30 and the XS15. The XS15 outside dimensions calculate to 4.33 cubic feet ^3 and the XS30 outside dimensions calculate to 5.625 cubic feet ^3. Power rating of the bash amps for the XS30 and the XS15 are 500w and 750watt respectively. Although there are ICE amps available for upgrades. I saw a pic of the XS30 with a sub out and it seems like a 25MM case heavily filled with sound deadening material. Even the new s3000i has the same size enclosure (better drivers) but a larger amp than the XS30 I am planning on sorta copying. I know I have to take wall thickness into account.

 

So I want a cylinder formatube or whatever 450mmx~1m for a volume of 5.61 cubic feet^3

I was planning a box a bit bigger for 600x600x600 (8 cubic feet) but I could make that a bit thinner if needed to match. I was thinking a little bigger might be OK here. But Ive no way to sim it or tune it ahead of time. Planning on using Inuke 6000DSP amp.

 

Anyway I need a ton of advice, but I was starting with a small question at first haha.

Edited by Troyus_

Share this post


Link to post
Share on other sites

I've just built two 600 x 600 x 600 sealed subs with 15" Eminence Lab 15 drivers and Dayton 500W plate amps.

I used 32mm ply from Bunnings that is less messy to cut and stiffer than MDF. Cost should be similar.

As for tube subs I have no idea.

I'm in WA.

Good luck though!

Edited by a.dent

Share this post


Link to post
Share on other sites

Very cool. Was that 1 sub per box? Im looking at doing 2 per the same box, just I have no idea on the driver specs. Did you sim your box beforehand to get those dimensions? What did you drivers cost? I see them on parts express and its about $380 each plus delivery. That would have blown my budget out.

 

How do they sound? Not sure how ply subs go.

 

Share this post


Link to post
Share on other sites

Just one driver in each sub. I got them cheap on eBay.

I ran one sub by itself initially. It really depends on your room size but one driver loads my 5.5m x 4.5m x2.7m room adequately.

4 drivers could be unnecessary overkill but I guess we all like that type of overkill.

I originally wanted to build my boxes out of 12.5mm Aluminium copying the Magico Q subs (http://magico.net/product/qsub.php) but cost was prohibitive and I couldn't do it myself.

32mm ply is stiff but I would suggest making the walls as stiff as possible so the thicker the better within reason. Bracing can help though.

You can come and have a listen if you like.

 

 

Share this post


Link to post
Share on other sites
1 hour ago, Troyus_ said:

Not sure how ply subs go.

 

With adequate bracing, think B&W Matrix style on 200mm centres, MDF will sound no different to ply.

 

If the drivers are the PSA units, without specs or the ability to measure them, simply clone how they're sold retail as complete subs.

38 minutes ago, a.dent said:

so the thicker the better within reason.

Thicker does not mean stiffer. Simple mechanical engineering.

I have 2 FTW21 in heavily braced 18mm MDF and there are now vibrations on the enclosures. Bracing is the key; see above.

Share this post


Link to post
Share on other sites
Guest BobbyD
49 minutes ago, a.dent said:

Just one driver in each sub. I got them cheap on eBay.

I ran one sub by itself initially. It really depends on your room size but one driver loads my 5.5m x 4.5m x2.7m room adequately.

4 drivers could be unnecessary overkill but I guess we all like that type of overkill.

I originally wanted to build my boxes out of 12.5mm Aluminium copying the Magico Q subs (http://magico.net/product/qsub.php) but cost was prohibitive and I couldn't do it myself.

32mm ply is stiff but I would suggest making the walls as stiff as possible so the thicker the better within reason. Bracing can help though.

You can come and have a listen if you like.

 

 

I found lining the internal walls with 5mm copper sheet quite useful...... Alas gets costly......good but.

Share this post


Link to post
Share on other sites
2 minutes ago, SETSergio said:

I found lining the internal walls with 5mm copper sheet quite useful...... Alas gets costly......good but.

To what possible electrical or mechanical benefit?

Share this post


Link to post
Share on other sites
Guest BobbyD
2 minutes ago, A9X said:

To what possible electrical or mechanical benefit?

Dampening resonance vibration.

 

using a 15” in each woofer enclosure, tightened things up.

 

Copper does not affect the magnets unlike steel.

 

I am but a humble diy’er.... don’t claim to be an expert like others.

 

Worked in my project.

 

:thumb:

Share this post


Link to post
Share on other sites

^^ Dynamat or mineral loaded vinyl would have worked better for considerably less money.

Share this post


Link to post
Share on other sites
Guest BobbyD
2 minutes ago, A9X said:

^^ Dynamat or mineral loaded vinyl would have worked better for considerably less money.

With respect, Have you tried copper?

Share this post


Link to post
Share on other sites

If you don’t have driver specs and copying box size of those same commercial subs  it would probably be ok assuming you know the wall thickness of the commercial cabinets. There might be minor differences in exact internal volume but a seal design is more forgiving compared to a vented box.

 

The sonotube will be harder and more expensive to do. MDF box sheets can be found in the gumtree much cheaper ($20 per 2.4x1.2m 18mm sheet) than Bunnings. You can sandwich glue two sheets of 18mm or other sizes or instead use 18mm and brace it a lot. See numerous web examples online to build and brace cabinets. It is quite easy to build a 60x60x60cm using clamps or strap braces, screw and glue, jigsaw the driver hole etc. If you choose Bunnings they will precision cut the sizes and provided your instructions are correct it can be spot on. 

 

Personally I wouldn’t bother with the sonotube.

 

I’ve built several half arsed experimental test subs and most have been very successful and they keep up with or exceed many commercial subs. I just can’t decide on which fantastic design to finally rest on - vented transmission line is my favourite, but normal ported and sealed with quality drivers are all good as well.

Edited by Al.M

Share this post


Link to post
Share on other sites
3 minutes ago, SETSergio said:

With respect, Have you tried copper?

No because it has no dampening capability whatsoever, whereas the two alternatives I suggested actually do.

 

WRT to the 'have you tried it argument' I also don't need to hit myself in the head with a brick to know it will hurt.

Share this post


Link to post
Share on other sites
5 minutes ago, Al.M said:

 

The sontube will be harder and more expensive to do

Im leaning towards getting help to build the box so it may cost a little bit. I dont know If I can do it.

 

The sonotube on the other hand seems easy. Just a tube with some round end caps :)

Share this post


Link to post
Share on other sites
Guest BobbyD
5 minutes ago, A9X said:

also don't need to hit myself in the head with a brick to know it will hurt.

No that is not required and no fun.

 

Sorry to get of topic and goodnight......:thumb::cool:

Share this post


Link to post
Share on other sites
2 minutes ago, A9X said:

No because it has no dampening capability whatsoever, whereas the two alternatives I suggested actually do.

 

WRT to the 'have you tried it argument' I also don't need to hit myself in the head with a brick to know it will hurt.

I agree copper would not have better damping. The usual recommended damping is felt or rubberised sheets glued on. 4mm commercial grade floor vinyl off cuts glued on has been proven to have equal damping based on accelerometer testing of cabinet walls.

Share this post


Link to post
Share on other sites
11 minutes ago, Troyus_ said:

Im leaning towards getting help to build the box so it may cost a little bit. I dont know If I can do it.

Boxes are easy especially if simple rectangular designs. Do you have any relos/friends into woodworking? If so, enlist some help.

8 minutes ago, Al.M said:

4mm commercial grade floor vinyl off cuts glued on has been proven to have equal damping based on accelerometer testing of cabinet walls.

I'll admit I hadn't heard of that one. Do you remember where you got the measurements as I'm curious. Might be a cheaper solution for some of the large (L/R + surrounds) boxes I have coming.

 

As for subs I've found adequate bracing is all that's needed even on very large boxes, like my 400L (four hundred litre) sub enclosures.

 

Sergio; it's your money, so spend it how you want, but when I see something that's not going to work, I'm going to comment so others don't go down the same path uninformed.

Share this post


Link to post
Share on other sites
30 minutes ago, A9X said:

Boxes are easy especially if simple rectangular designs. Do you have any relos/friends into woodworking? If so, enlist some help.

I'll admit I hadn't heard of that one. Do you remember where you got the measurements as I'm curious. Might be a cheaper solution for some of the large (L/R + surrounds) boxes I have coming.

 

As for subs I've found adequate bracing is all that's needed even on very large boxes, like my 400L (four hundred litre) sub enclosures.

 

Sergio; it's your money, so spend it how you want, but when I see something that's not going to work, I'm going to comment so others don't go down the same path uninformed.

Accelerometer testing of damping or vibration of vinyl floor tiles or sheets was done some years ago on the Madisound DIY speaker forum by some engineers producing similar results. Vinyl off cuts can found for free at suppliers or building site waste bins.

Share this post


Link to post
Share on other sites

5mm copper sheet must cost a fortune, where do you even get it from??
Anyone tried making boxes out of an acrylic like Corian benchtop material?

Share this post


Link to post
Share on other sites
58 minutes ago, swervyn said:

Anyone tried making boxes out of an acrylic like Corian benchtop material?

Wilson use something similar, but I've yet to see any evidence that it's better than well braced MDF/ply.

 

As I've mentioned before, I've had 2 x FTW21 21" sub drivers (not opposed) in a 400L well braced MDF box and couldn't feel any vibrations. And I should know, I used it as a foot rest.

 

Seems to me in audiophilia, everyone wants to try the exotic/extreme method before working with basic engineering methods that actually work.

Share this post


Link to post
Share on other sites
35 minutes ago, A9X said:

 

Seems to me in audiophilia, everyone wants to try the exotic/extreme method before working with basic engineering methods that actually work.

Nah, not really in my case. As a cabinetmaker I have plenty of different materials to choose from, just wondered if 12mm acrylic might of been a superior alternative. 
 

If you want to 2 pack paint mdf you generally need to mitre the corners as butt joins always show thought the paint unless you put a squillion coats on, and even then will most likely show through, no problem if you are going to veneer over the mdf.. Acrylic with an epoxy joint wont have that problem and can still be coated with a 2K finish

 

My question was more on the finished product appearance rather than the basic fabrication of a box, sorry, should of made that clearer

Edit: plus I have plenty of 12mm acrylic benchtop offcuts that would do the job

Edited by swervyn

Share this post


Link to post
Share on other sites

http://swpaustralia.com.au/

I emailed these guys and they say they might have some offcuts for me to look at in concrete form tube. Good lead. However it looks like plastic or some sort of weird material. How you think it will go as a sonotube?

Still cant find any formatube here.

Share this post


Link to post
Share on other sites
Guest
You are commenting as a guest. If you have an account, please sign in.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoticons maximum are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

×