Subwoofer DIY for HT (1 Viewer)

[corvette]

I would like to build my own Subwoofer as I read in most of the post that it is worth a saving.

I built speakers before but from drawings and I am not able to calculate the dimension the volume and adjust the bass reflex.

Reading some posts in these forum I can see that some of you seems pretty sharp on what to do on subwoofer.

What kind of Subwoofer should I build for $4-500.
This does not include the price of the box but only the speaker (s, driver , radiator?), the amplifier, and the electronic.

For the 8 other speakers I will have installed HTD HDW-80 (not purchased yet but I heard it is difficult to get more from your bucks) with a 1.2 cuft perfectly sealed enclosure.

could it be possible to have a potentiometer to adjust the filter for the overlap with the other speaker.

BTW the volume of the enclosure is not an issue as it will be under the stair and I have plenty of room overthere.

The volume of the room is 3000 cuft.

Should I go with two Sub to cover more audio spectre

thanks for your help

 

[Robert_J]

The best bang for the buck would be to copy a sub from Elemental Designs. Order their 4 ohm (or dual 2 ohm) 18" driver and 550W amp. Build an enclosure the same size or a little larger than the one in the link. Brace it properly. You are done.

You don't want to overlap frequencies with your mains. It makes integration of the sub more difficult unless you have the proper measuring tools.

Again, two subs are more difficult to integrate unless you are keep them close together. But it is just easier to build a single, larger sub.

If you want to increase your budget, many more options open up for you. You can go ported in a larger enclosure. You can use better drivers from Fi Car Audio or Soundsplinter. You can use a pro amp which gives you MUCH more power for just a little more money.

-Robert

 

[corvette]

Robert,

This is really helpfull.
If I read this correctly I will need to buy a 190.V2 D4 (4 ohm) and a LT 550 amplifier. then to build an enclosure.
I read that the ported enclosure is better for HT. how to get the exact diemsion of the ported one?

When you say a little more money how much are we talking?

no I do not want to overlap the subwoofer with the other speaker. I will be able to adjust if with the subwoofer amplifier. Is this correct?

thanks for your help

 

[Robert_J]

There are no 'exact' dimensions for a DIY sub. That's the great thing about them. They are totally unique and fit your goals exactly as you define them. But if you need help, then you need to start by finding the largest enclosure size possible. I can help you work backwards from there using Unibox (my favorite sub modeling software). Ports would add a little to your cost but not that much.

The upgrades I mentioned can get significant. A Behringer pro amp will cost you about $325 shipped but it also provides 1,600w of power at 20 hz. That's 3 times the eD amp I linked to. For the drivers, you will need to look at models from Fi Car Audio and Exodus Audio. Those will cost $350 to $400. You can go up from there with amps from Crown, QSC, Carvin or Face Audio that are $1,000+. Drivers from Audiopulse are equally as expensive if you can find them. Or you go with multiples of lesser drivers.

Your receiver takes care of the crossover duties. If you don't have a receiver with a sub-out or LFE out jack, then we need to look at adding additional equipment.

-Robert

 

[corvette]

If what I am reading is correct I should plan to spend $700 to have something much better.
I am ok with this.

My HT amplifier is a Yamaha DSP 1092 and has 2 LFE bass out.

for the volume of the subwoofer I do not really have restriction as it will be under the stair and can use what ever is best. it could be as wide as 3' and as deep as 3' too. for the height I would like to stay under 4'
so as you read we have some room there.

The other solution is to make a box about 3' x 3' and about 2' high. this will be the corner of the 2 sofa making a table.

 

[Robert_J]

Is $700 your max budget and 3'x3'x2' your max size? If so, then I'll work on finding some designs for you.

-Robert

 

[corvette]

let me verify the exact dimension and I come back to you.
For the budget yes let stay aound 700 but again if it is 725 it is ok.
thanks

 

[corvette]

Robert,
I will be ready to move on soon.
I was waiting to have the furniture (sofas) purchased before contacting you again. I am glad I did it.
The room I will have for the sub will be different from what we talked. I will insert it between modular sofa. It will be like and arm chair.
what do you think about the idea?
then I will have like 24" in width 36" for the depth and could be 24" high. This makes a 12 cuft of volume. Is this enouygh or should I revise the dimension.
could the speaker face the floor? or do you recommend to be horizontal?
Is this the speaker you were recommening?
DIYCable.com : Intro » Home
thanksproducts_id=681
I look for FI car audio and only subwoofer for car?

 

[Robert_J]

Your link for DIY cable doesn't go to any particular product. But if you are referring to the Malstom-X then that is a massive sub. Yes, that one will work just fine. As for Fi being for cars - we don't listen to marketing labels. The sub's Theile/Small parameters determine where it can be used and Fi subs work well in both home and car environments.

As for your 12cf enclosure. That is the gross volume. We look at internal size and that is always much smaller. But it does sound like a size you can work with. Between the Exodus, Fi or even the eD sub mentioned earlier you can get a great sub built.

-Robert

 

[corvette]

Yes I was refering to the malstrom-X
I look at FI car audio and found the BTL 18.
I will follow your recommendation between both.
As far as the enclosure yes the 12cft is gross.
If you feel that this is too small we can make it higher increasing the 24" to whatever you feel will be necessary.
we can also slighly increase the depth from 36" to 40"
I cannot change the 24" of width may be 25" but no more.

 

[Robert_J]

If I'm not mistaken, the Fi BTL is their SPL model. Super high BL (magnet strength) but very poor sound quality. The car guys just want to burp it with 10,000w of power for 3 seconds.

Let me run some simulations on the Malstrom and see what I can find.

-Robert

 

[Robert_J]

For a sealed sub, just build as large as possible. 200L will give you a Qtc of .707. I like a Qtc closer to .5 so the larger you go, the closer you get.

If you want to go ported, I recommend a Neo Dan Easy Button design - link. It is a low end monster.

-Robert

 

[corvette]

I did some search on the AVS forum and found a post on how to build a ported box.
IXL 18 meets the easy button.
is this the post you were refering to?

I have no knowledge on sub but I heard that ported is always better.
Is this statement true?

I also read that some are using two passif radiators like the EX-PR18. Is this better?

 

[Robert_J]

Ported and PR are the same. PR's cost more than ports so that makes the budget go up. You can use PR's with smaller boxes. But properly designed and built - sealed, ported and PR enclosures will all sound good. It all depends on what your goals are.

-Robert

 

[corvette]

So I think my choice is made.
i will go with the neon dan easy max 24"x26"x37.5"
ported.
The malstrom-X and the behringer ep 1500.
Robert are you selling the behringer?