DIY 12" Mega SUBWOOFER

rakesh_sharma23

rakesh_sharma23

Do It Yourself
Adept
Hello to every one.
Here are my some more mod thing.
Currently i modded my Sound blaster Audigy Value 7.1. Installed new Op-amps Burr-Brown OPA277 and Capicitor mod.
It improved sound quality a lot...But now i think i Should have new SUBWOOFER..

So here i am with my own Power Sub-woofer.
DIM:-
14inc X 14inc X 18inc Sealded Encloser made from 1/2 inc thick MFD board.
12inc - 4ohms - 800Watts Sub- drive
home-made 450watts amp.

Have a look
SUB
sub01he2.jpg

sub02it1.jpg

sub03lp0.jpg

sub04kq0.jpg

sub05qw6.jpg

sub06fg2.jpg

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sub08sq0.jpg


12inch drive with Huge 8inch magnet
sub09pw7.jpg


450 Watts AMP
amp01ck1.jpg

amptopae1.jpg


Playing crysis with this Subwoofer is mind blowing.....

Hope you like it
 
**** :O awesome.. does this beat Logitech Z-5500 sub?

3k is cool :O where r u located? if located in mumbai pls tell me, ill come for a demo :D
 
good job there rakesh!!!

Had seen your work somewhere else before, forgot where, and was wishing when you'd join TE.

Wait for our in-house DiY gurus to pitch in.
 
@rakesh sharma
congrats:) i had done a similar thing 6 years ago except that i used a 18x18x18inch bass reflex enclosure and a bolton 12inch sub and i lazy to build a amp, so just screwed a sony car amp and was powered by my inverter battery,it was done to assist my gigaworks sub, the DIY sub goes so low that u dont hear the bass but can feel it,while my gigaworks 8inch sub gives me a tigher bass.

anyway for the aesthetics i used a sticker which looks like rosewood finish rather then the painting it.
 
good job :hap2:

a few doubts:

split up of the prices?

why 1/2 inch MDF? 3/4 inch would have been a much better option

any sort of enclosure design involved ?

where did you get the sub from? IMO it doesnt look too good , but if it sounds good , that should be enough.

what are the main speakers ?

where did you get the amp design? appears to be a class D
 
Rakesh: You're a prolific DIY'er, so hats off. I'll be following your work, many of the greats started off like this. I can't be bothered to get off my arse and actually build something that takes grunt.

There are obviously things that I see and things that I don't, but keep on this path and you'll see success.

Enjoy your creations, as I do looking at them :)
 
Thanks to everyone....It's very nice to hear from you all ...

Some answers ;;:
My sub is driven by 450Watts on 4 Ohms of amp.
It's a cLass D Amp with 8 Darlington Transistors in Power section. I found this disign in A turkish form but it was just a prototype, Having huge distortion problem.. I redesigned it. Now it's just 1% distortion on Max power.

Box is a Sealed Enclosed Tuned up to 20Hz.
Made from 1/2inch MFD Board. Box is coated from inside by sound damping form.
Drive is a local 12" Car sub. I have tested many local drives but this was giving a noise free hard bass. so i picked this drive.

Overall The Sub gives a earthquack experience on MAX power.
Every door and window of my room begains to vibrate very loud. Even my double bed also vibrates when sub is in action....

While playing Crysis a close blast just give a heart vibrating experience.

I don't know about if my sub beats Z-5500 SUB, but i have compired my sub with a friend's Sub who is having professional DJ works. His 12" sub beats mine in an open place, but when played inside a hall my sub just overperformed the professional stuff.

Ones again Thanks...
I live in Jodhpur Rajasthan..
Any one want's to see my rig or setup are heartly invited..
 
Rakesh,

That doesn't look like a Class D amp. There is no output filter or PWM modulator on the board, unless it's on the bottom. It looks like a regular Class AB symmetric amp to me - if it IS a Class D, that output inductor looks awfully undersized to me, and I wonder why you needed so many additional components, as the Tripath modules are much cheaper and require very few output components to hit the kind of power you're using, and don't need as big a heatsink either. If you're open to it, you might want to try something using the LM4702/LME498xx series, they greatly simplify amplifier design and reduce cost as well. You can reuse your output transistors and transformers.

My other feedback:

A single large heatsink would get you better results than the half-and-half section you've got with the fan on one part of the heatsink. You will reduce distortion significantly if all the output devices are on one heatsink, so that the two halves track better with changes in temperature - bass distortion is not terribly noticeable anyway, but it would be nice to not have. Of course I'm not 100% sure this is the case as your shots don't seem to be taken at similar angles.

I also cannot see any thermal compensation anywhere, but I haven't seen the schematic so can't say whether you need it or not - but any bipolar transistor needs protection from thermal runaway.

Sealed is a good decision, but some bracing is a must. I don't wonder that everything vibrates, and you're putting the box at risk of explosion. Stuffing the box will also help reduce the Q so the sub will go deeper and have less ringing and energy storage issues.

My final comment is that 4700uF is too small a capacitance for a subwoofer amp. At 450 watts into 4 ohms you're pushing about 11 amps into the speaker, which means at least 15,000uF in my book, you're only running a third of that. There will be rail sag, and a lot of it. I would technically use at least 30,000 uF myself. A few capacitors in parallel connected directly to the board, or an external bank with a rectifier hooked up to this would be a good mod in my mind. Of course the on-board rectifier would not be used in this case.

Again, these are not to take away your effort and perseverance on this project - after all, this is "Show-Off" section. If you feel like discussing further we can catch up on PM.
 
Nice execution of work there.
can you share the amplifier circuit diagram? is the pcb readily available in market?
 
As i said Desigh was a prototype from a Turkish form, with huge distortion,
I have redesigned it, and made the PCB my self..

No Market made stuff All DIY ...

Thank Sangram, 4700uf caps were used in testing.
you can see huge 10,000uf cap in place when amp is in the Box.

Thanks
 
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