DIY Subwoofers

[The Icebun]

I have started to look at building my own subwoofer but have a few questions.

1. Do any of you know of any suppliers in the UK for drivers and crossovers. I've foundsome drivers on Maplin and RS but would prefer to order from a more specialist dealer.

2. The lowest that the drivers I've seen on Maplin and RS will go down to is around 30Hz. The manual for my main speakers (Eltax Symphony 8.2) claim that they will go down to 28Hz. Am I right in thinking that I need a driver that will go lower than my mains ? Or is the figure quoted in the Eltax manual a bit inaccurate.

3. Does anyone have any experience of self build subs ? I know there are loads of US based websites but I'm looking for a UK perspective.

[MikeK]

Originally posted by The Icebun
I have started to look at building my own subwoofer but have a few questions.

1. Do any of you know of any suppliers in the UK for drivers and crossovers. I've foundsome drivers on Maplin and RS but would prefer to order from a more specialist dealer.

2. The lowest that the drivers I've seen on Maplin and RS will go down to is around 30Hz. The manual for my main speakers (Eltax Symphony 8.2) claim that they will go down to 28Hz. Am I right in thinking that I need a driver that will go lower than my mains ? Or is the figure quoted in the Eltax manual a bit inaccurate.

3. Does anyone have any experience of self build subs ? I know there are loads of US based websites but I'm looking for a UK perspective.



1. Try www.wilmslow-audio.co.uk
CPC also do speaker drivers and crossovers, and also do a plate amp for a subwoofer. (never used these products though)

2. Figures can be made to say just about whatever you want. I very much doubt that your Eltax speakers will get anywhere near 28Hz at a realistic output level, but very generally speaking, you would be looking for something which can get below that.

3. I've never built one (yet), but bass is bass, whether it's US bass or UK bass.


Get some design software first, and check out the box size calculations. Some bass drivers are deigned for very special applications, and won't work that well in a standard sealed box, or even a standard bass reflex box.
The Scanspeak 25W-xxxx bass speakers are reputed to be very good - but again never used one myself.

[blair]

IPL Acoustics in Devon do a kit which includes everything - driver, amp and cabinet, they have an interesting and detailed website. Somebody did a thorough review at avforums a while ago and although he still preferred his REL he did say it was excellent value

www.iplacoustics.co.uk

[Boz]

Hi

I recommend a Shiva or Tempest from Adire Audio http://www.adireaudio.com/

Gary Griffiths is the UK dealer, email-
sales@adireaudio.co.uk


www.wilmslow-audio.co.uk don't really have SUBwoofer drivers. They're more woofers.

For true sub-bass you need a large diameter driver (12" and above) with a low resonant frequency (Fs) and large excursion (Xmax).

The Shiva and Tempest from Adire Audio are used widely in the US and there are many tried and tested enclosure designs available. Check out the application notes on the Adire site for different enclosures. I use a Shiva in the 142.5 EBS ported enclosure, powered by a 300W mono amp from http://www.bkelec.com/

More examples-
http://members.tripod.com/~terryctheater/shivaphotoalbum/page12.html

The http://www.hometheaterforum.com/ have a very good DIY forum and you'll get excellent advice there. Adire also have helpful tech support.

I'd do as much reading and research as possible. Try and learn all the basics of subwoofer design. Try these-

http://www.diysubwoofers.org/

http://www.snippets.org/ldsg/intro.php3

http://home.earthlink.net/~etunstal/diy.htm

Good luck! :)

[Bapapapa]

Build a six foot Sonosub!! :p

[SimonInd]

I'm in the process of completing a sealed sub-woofer based on Adire Audio's Tempest. It's big and only screwed together at the moment ( needs to be glued and stuffed ) but already it sounds fantastic. On the amp front I've gone for a 500W Bass Panel from http://www.bkelec.com which is potentially overkill, but I only intend to build one...

I got my Tempest from Gary Griffiths in the UK, it was cheaper than trying to import one myself, and have just used Adire's 230L design on their website. With the aid of a 40 quid router from Homebase and some cut-to-size MDF from a timber merchant I'd got the box to it's current state in just over a day.

So far I can't recommend it enough and I know than when I seal and stuff the box it's going to sound even better:D

Simon

[Bapapapa]

SimonInd - How much was the driver?

[lynx]

Originally posted by The Icebun
I have started to look at building my own subwoofer but have a few questions.

3. Does anyone have any experience of self build subs ? I know there are loads of US based websites but I'm looking for a UK perspective.
I have built a few subs for in car use and the one thing on which parallels could be drawn is enclosure design. It is imperative that you choose wisely and ensure that the enclosure material will not flex under operating conditions. Port design is also critical and one thing I found out long ago is you cannot always trust driver manufacturers to provide accurate information on what is suited to their products!!! Many use proprietary box design software which is hopeless rather then proper r+d. Do you intend on using a ported or sealed enclosure?

[SimonInd]

How much was the driver?

I paid Gary Griffiths £139.95 which included £15.00 shipping for a Tempest. If you want to order from Adire direct then it'll be $140.00 plus shipping to the UK ( bear in mind it's about 9kg ) and you may get stung by customs!

To total cost of my sub so far is about £400 but then I did go for a 500W amp:D A less powerful amp would easily do the job and reduce the budget, however I'd recommend getting one with all the LF Filter controls as mine seems to sound better running off the Front L+R signals rather than the dedicated sub output ( at the moment ).

I'll probably spend a few more quid making it look pretty but at the moment I'm just enjoying the sound of it - it's now glued and stuffed and it's sounding even better - producing the sort of bass that puts a smile on your face....however it does mean that my Epos floorstanders sound a bit weedy on their own.....

Simon