Sub: Volume of Enclosure with Amp

[Kanga]

Thanks Allan

I'll e-mail Acoustic Concepts if I want more info. Just interested for future reference.

BTW, putting the amp in a separate compartment is probably the best way to do it, but if its a hassle, I wouldn't be too worried about mounting it in the side of the box, like almost every one does. The ear is pretty insensitive to distortion of low frequency sound, so you're very unlikely to hear any microphonic effects caused by sound and vibration from the box. If you were talking about the midrange, then I'd be more inclined to agree with Pinkmouse. Just my opinion, and not backed by any experimentation or a 5 year warranty .

Also - given that you are using a sealed enclosure, I wouldn't be worried about the volume of the amp at all. It will increase the Qt, but only very slightly (maybe from 0.707 to 0.717, which is insignificant).

Mick

[JOE DIRT®]

Cheers Allan...your starting out with a good concept....once you get this going and your veins get filled with adrenalin...you`ll keep needing a fix to build some more projects......lots of support here for anything you want to do.......and on a final note....we all have quandries here...questions are not stupid...they show interest

DIRT®

[bigkid]

Thanks for the input kanga, Joe. Will post the results in due course.

[DrSmith]

I'm also building a sub based on the Adire Shiva (142.5 L BR).
I already had a seperate room planned for the amp and when I got it, the manual recommended the amp to be placed in a seperate room. This to avoid any strain on the components of the amp, caused by the enormous air-pressure

[mike]

Hi Bigkid

How's the project going? Having already built some floorstanders, I'm looking at doing something very simular t owhat you've outlined.

I'm familure with the Redgum Amp, but I was wondering what driver you were using, and how much it cost here in Australia.

Thanks!

[bigkid]

Hi Mike,

Little slow on the project I am afraid, got to juggle it with painting the house. I am going with the Adire Shiva 12inch driver using their 55 litre design:

http://www.adireaudio.com/Files/Seal...cations.PDFbox

I intend to use a linkwitz transform circuit with the following components

C1 = 0.51 uF
C2 = 0.047 uF
C3 = 0.22 uF
R1 = 25.4 kOhm
R2 = 65.5 kOhm
R3 - 63 kOhm

to give me a Q of .707 and, with the Redgum's 3db boost per octave below 20 Hz, a -3db response at somewhere just below 20Hz (if I have the maths right of course). I found this site helpful in getting my head around this stuff, the linkwitz site is too technical for me: http://sound.westhost.com/linkwitz-transform.htm

You can get the Shiva from John Woodhead who appears to be the local importer at: www.acousticconcepts.com.au for about $272 + $17 delivery. He also has the Redgum for about $395. The Shiva seems to go for about US$125 (in the US). Probably cost about A$250 to get it over the net with delivery so I'll get mine locally from John in the next couple of weeks. Worth the extra $22 for piece of mind.

I got several helpful emails from Adire and from John Woodhead about the design. Happy to send them on to you if you wish.

Good luck.

[bigkid]

Mike,

I sent a couple of emails to you in response to your email sent via the diy website. Haven't had any in return. Did you get them??