Pics of my DIY sub (if anyone is interested)

[Ramius]

I though I show a couple of photo's since DIY
was being discussed and dismissed in the RELQ50 thread.

It's an EBS enclosure using Adire Audio Shiva driver and the application plans from their site- http://www.adireaudio.com/

Specs-
External dimensions 21" x 21"
Box Volume 142.5 litres
Fb 18.1 Hz
Vent 4" Flared, 17.2" long
Anechoic F3 17.8 Hz
Anechoic F8 14.5 Hz
Anechoic >105 dB SPL 16.3 Hz
In Room F3 16.3 Hz
In Room F8 13.7 Hz
In Room >105 dB SPL 13.7 Hz

The pics don't do it justice. It looks a lot better in the flesh and sounds amazing, take my word for it ;-)

The third photo is the braced box interior before the front baffle is screwed and glued in place.
http://photos.yahoo.com/bc/boz001uk?...src=ph&start=1

Any questions please ask.

Cheers

[General Skanky]

Very nice.
Having followed some of the links you sent me, I'm more and more impressed with the DIY route to things.
It's really amazing what can be achieved with a little effort.
You're sub is miles better than I had imagined.
(My wee REL is still a double hard b*stard though!)
I'm certainly a convert to DIY speakers.
In the future I shall be looking at that before! just going out and buying manufactured equipment.
Cheers.

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Douch!!......Wot's da madder, da CIA got you pushing too many penzils?

Work: www.hughes-tv.co.uk

[This message has been edited by General Skanky (edited 08-11-2000).]

[simonsez]

Ramius, I have always been interested in DIY speakers. I was of course skeptical at first, but the more I read, the more intrigued I became . I now have a subscription to speaker builder magazine and have been planing on building either a subwoofer or a pair of bookshelf monitors. Your beautiful subwoofer has inspired me to give it a try.
Here are a couple links you may be interested in: http://diydrivers.stryke.com/
http://www.audioc.com/
http://hometheatertalk.com/DIY_Proje..._projects.html
http://www.madisound.com/

Perhaps if enough people get interested in DIY we could ask Blade to set up a DIY Projects forum. Anyway, you did a great job on the sub, especially the finish. Are you planning to build a grille cover for it?

[Ramius]

Thanks General.
That's another good thing about DIY, being able to say "I made that". I've never had such job satisfaction in my life. Your mates come round and see and hear it saying- that subs excellent, "Thanks, I made it" (even my girlfriend was impressed). It's sad, but you feel proud of your work.
I hope you start DIYing something as soon as possible, be warned it's additive, just like the upgrade bug. (I'm gonna build another next year.) ;-)

simonsez, again, thanks.
I've been reading up on those Stryke drivers they look pretty special. From what I understand it seems they have been designed for use in a small box with a couple of Strykes passive radiators and bags of amp power. I don't mind having a big box ;-) as I have the space, so I don't think they're for me.
You should get building now. You have many more resources available in America.
I'm sure if/when DIY becomes (more) popular in the UK they'll be a DIY forum, I hope.

Cheers & thanks again.

I'll definitely be taking a look at the DIY route. I am currently looking at the REL St series of speakers (Storm III or Strata III, Stadium too expensive), and I think that a DIY sub would be less expensive. I will now add DIY sub to my list of possibilities...

[Ramius]

Here's some DIY links for those who are interested. http://www.adireaudio.com/
This is a very informative site. Loads of info regarding all things.
For those thinking of building their first DIY sub I suggest using a tested design. See the various applications on this site. If you import a driver from the US you will get stung by import tax and things (adds about £30 to the cost of the driver+shipping). Shiva works out to be about £140. IMO still worth it.

Lots of interesting info here- http://www.audioinnovation.com/
Have a good read, check the links.
http://www.bkelec.com/ is an excellent source for power amps.
http://www.linearteam.org/winisd.html
WinISD is freeware speaker designing software.
It's also very educational. Playing around with it will teach you a lot.

I hope this temps more people into trying DIY it's worth it.

Cheers.

[Ramius]

Since I posted a couple of pics, I thought you may like to see frequency response measurements. These were taken at the seats using the RadioShack SPL meter with correction vales added.
These are NOT max SPL measurements, (I value my windows and ears).

Hz dB
16 90
18 90
20 90.5
22 90.5
24 90
26 89
28 89
30 89
32 90
34 93
36 87
38 88
40 87.5
42 87
44 88
46 88
48 85
50 84
52 85
54 86
56 87.5
58 83
60 83
62 87
64 88
66 88
68 86
70 83
72 81
74 81
76 81
78 80
80 75

Not too bad eh? Good extension. A couple of slight room nulls and a peak. EQ needed to eliminate the 34 Hz peak.
The first position in the room I placed the sub, I was sat in a 20 dB room null at 45 Hz. Now that was bad. I had to reposition it.
Everybody owning a sub should plot the response and make sure they're not sat in a null or 'room gain' induced peaks. A badly positioned sub sounds terrible, the words dull and boomy spring to mind.
Hope I'm not boring too many people. ;-)

Cheers.

[Dodgey]

Ramius, I used to build subwoofers for my own and friends cars when I was younger and before affordable car-subs and amps hit the UK.

I love the look of your HC Sub. Couple of questions...

1. What's all the internal structure for - Rigidity? I thought it might have been a band-pass or a horn band pass design for about 1 second until I noticed all the holes!

2. Do you get any port / wind noise?

3. Did you have to tune your port much?

4. What power are you using?

5. MDF?

I'll read the tech facts elsewhere of course but if you could answer these questions then I'll proceed. Very interested to know how you got on. Done a lot of this sort of stuff myself in the past but not quite as tidy (does not matter so much in boot of car ). How did you get the shiny finish?

Cheers

[Ramius]

dodgey,

I did a bit of car stuff when I was younger too. ;-)

Yes, the internal structure makes the box stiff and strong and stops the box resonating and flexing. Apparently it's essential.
The plans are from here- http://www.adireaudio.com/Tech%20Papers/shiva_apps.htm
It's the 142.5 liter vented enclosure. Mine's being used on it's side so it's front firing. I like to see the driver and it was a bit easier this way, no need for feet.

I've listened to DVD's very loud, (not far off reference level), I've never experienced port noise. However if I play low frequency high amplitude tones (in short bursts, I don't want to melt the voice coils) it does chuff,
(it also gives you a headache for 3 hours.)
As you know, if port diameter increases then so does port length for the same tuning. I built my sub from the plans mentioned above so I wasn't worried about port noise and tuning. I like the idea of using a tried and tested design (especially as I'm still learning).

It's powered by a 300 Watt mono amp from http://www.bkelec.com/ (in the Modules & Hybrids section- OMP MF300) and I'm also using the Sub Bass Filter. A little soldering is involved.

As the plans are from the US the measurements are imperial. The plans use 3/4" MDF which is not common over here. Fortunately Arnold Laver http://www.timberworld.co.uk/ (main branch is one mile from me) stock it. It's about £20 for a 8' x 4' sheet. I paid a local carpenter £40 to cut all the panels to size.
In the US SonoTube subs are very popular having various advantages over tradition box subs- http://members.tripod.com/~terrycthe...um/page12.html
You can find this stuff in the UK with a bit ringing around. I think my next years project will be made out of this. The stuff I found was called Rapidobat, BRC supplied it.

The high black gloss finish was achieved using car spray. The box was sanded, undercoated and sanded then spayed, then wet sanded then spayed again. I used about 10 cans at £5 a can. Next time I think I'll use a different method. High pressure plastic laminates, veneer, Covered in fur? I don't know.
If you search on the various US forums http://www.hometheaterforum.com/ you'll find various finishing methods discussed.

Total cost was about £450 with 300 Watt amp, (and that's also including the £40 carpenters fee for cutting the panels and £50 of paint.)
And it does sound very good.

Hope this helps you to get started dodgey ;-)

Cheers.

Very Interesting.
Have you considered submitting your DIY subwoofer with plans etc to Home Cinema Choice for review ?
I'd be interested in seeing how well it stood up against the pro boxes and I'm well prepared to eat my words.
Give them a ring - 020 7331 1000.
Steve May is the editor.

[General Skanky]

Good idea. It would be very interesting to see just how much commercial subs differ from DIY considering the price difference.
Go on, do it.

------------------
Douch!!......Wot's da madder, da CIA got you pushing too many penzils?

Work: www.hughes-tv.co.uk

do you go by the name of Graham Auld perchance?

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'This one's got a bad mmooooooooooooooooootivaaaaaaator (in a very camp voice)'

[Ramius]

HC Dude
Adire Audio own the Copyright for the plans of this sub, so I don't think it would be wise to do what you suggested, even though they are for general release and anybody can use them. Anyway, how can a man live without a sub?? ;-) (Who would send away their pride and joy?)
I read your home cinema website with great interest. What a story, so much work. Now that is DIY! I'm very impressed (and jealous, amazing screen shots, one day hopefully I'll have front projection). I see you have a REL Studio II in your possession. ;-). I bet that sounds sweet. I'd be interested to see the in room performance. Could you take some measurements at the seats?

Does anybody fancy taking measurements of their own commercial sub? I know this won't give any idea of how they 'nice' they sound but it's an indication of performance.
Don't forget to add the correction values for the RadioShack SPL meter (analogue).

Come on General. You must be starting to believe. ;-)

Jesus H, no I'm not Graham Auld (if you were asking me)

Cheers.

[simonsez]

Ramius, I have two Energy EX10 subs...rated at 100w each. I'll take some room readings here in the near future. What test disc did you use? I would also be interested in seeing the performance below 16Hz. I am curious if the rolloff would occur in even steps indicating a great driver and box design.

[Ramius]

My test disc is home made ;-)
I used a sine wave generator to create various wav files and my friend burnt a CD for me.

Cheers.

[This message has been edited by Ramius (edited 13-11-2000).]