Hi all,

Dunno if any of you remember a post of mine a while back stating how I was going to build a nice big sub based around the Shiva MKIII and DT300... Well, it's been finished for well over a month now but I totally forgot about reporting back with my results (too busy enjoying DEEP bass)

Before I get onto the pictures, here are the details:-

•Adire Audio Shiva MKIII 650W long-throw bass driver
•Detonation DT300 Class D Sub Amplifier (300W)
•95 litre, ported enclosure tuned to 22Hz with double-flared reflex (83mm diameter)
•20mm thick Birch Plywood construction on legs for downwards firing
•Stained with laquered finish
•Approx weight 45kg

First, here's a graph of how it models in Bassbox Pro:

Of course, the graph is simply based on a number of parameters so you can expect more of a hump around 100Hz and for response to drop sharply around 2KHz in real life.

Now for the real pics

The building process:-

And the finished product:-

And here it is in its natural habitat - the jungle that is my bedroom/entertainment centre. Note the cunning use of wires and general mess to give the effect of a full room. If you're looking for clues, it's the big huge thing hiding behind the right hand speaker

You've probably noticed the finish isn't amazing - that's what you get for £20 with a French polisher who can't be arsed.
There are three things wrong with it:-

1) He didn't get rid of the router burn marks on the corners
2) He didn't do anything with the filled screw-holes (darkening them would have been nice)
3) He didn't even bother to laquer the underneath

Still, all is not lost because a few months down the line I am going to get the entire thing sanded down again and this time get a lovely piano black finish (the sort you can see your face in)

It does actually look a lot better in real life, and the grain in the birch is beautiful.


You're maybe wondering how it sounds? In short, FANTASTIC. I've never heard bass like this before - so smooth, controlled, immensely powerful and above all - DEEP. It always keeps up and never gives in. Even the most demanding drum 'n' bass at ear-splitting volumes doesn't frighten this monster - it relays it with tremendous accuracy and literally shakes the clothes and hair of anyone stood in my room (not to mention rattling everyone elses doors in the house).

It's also pretty damn amazing with films. The opening scene of Matrix Reloaded where trinity dives out of the window shooting bullets as she falls has an incredibly deep sub-bass rumbling that had everything in the room vibrating like never before. My old Yamaha YST-SW80 at this point was pretty much turning inside out, creating loud clicking noises as the driver bottomed out - it just couldn't keep up and the rumble wasn't even audible (in fact, I didn't even know it existed until I got the new sub). With this beast it was quite scary and the best thing is that it did it with ease and had plenty more power left. Also, that part where Trinity smacks the guy with her biker helmet; me and my girlfriend actually felt it pound our chest. I dread to think what this would be capable of with 600W amp!

Anyway, enough yacking - as you may be able to tell I am rather pleased!

Can't wait to build my next one, I'm thinking of a sealed enclosure or maybe a passive radiator.

[franc]

Hi. Well done. I would love to make my own sub...how much did it cost for the parts and where did you get them from?

many thanks, regards Franc

Hi franc,

The Shiva MKIII, reflex port, rubber feet and gasket came to about £165 inc. delivery from design3dw3.

The DT300 sub amp cost around £150 inc. delivery from BK Electronics.

The Birch plywood etc. actually cost me nothing as my dad has a joinery company Although to buy it would probably cost around £60 for a sheet, which would be more than enough for one sub.

Oh yeah - the satin finish cost me £20, although when I get the entire thing done in Piano Black it will cost a fair bit more for the paint and high gloss etc.

[micb3rd]

IT Looks great BigToe, I bet you are glad I surgested the idea to build one of those back on tech-pc.

That old Yamaha was barely a subwoofer in comparision.

I fancy a play with a Shiva sometime, I have so many subwoofer ideas/designs, but no time or funds to do them at the moment.

Yes Micb, I'm very grateful you pointed me towards this forum too - otherwise I'd be sat here with a budget REL instead of what I have now.

I sold the Yamaha on for £60, you are right - it is barely a sub in comparison. I thought it sounded good when I got it, but when you haven't heard anything better you don't know what you're missing.

You should definately have a go with a Shiva sometime. As you're probably aware it models very well in a sealed enclosure and is supposed to sound tighter (at the expense of a little efficiency, but who cares with 300+ watts).

I've got my eye on the 18" Maelstrom now - that is one superb driver!

[Starkiller]

Well done, looks like a nice piece of kit,
the contact for Amp will probably be usefull too

I have offen thought about making an AV Sub.

I made a sub box for car (polo) using a 15" JBL in a 3cuft box with single port tuned to 27Hz it was evil(in a good way) i could make any passenger sick, at normal volumes it sounded great too. after i sold the car its just sat in a cupboard doing nothing.

I could get an amp(if it runs ok with 4ohms) or use a spare car amp with a 12v 20amp PSU, and build an enclosure simalar to yours. I think would go for a small volume, perhapes 1-2cuft.
not sure how it would sound in a bigger room volume, probaby better as it might tone it down a bit.

I would def give more kick to the Pod racing scene in SW

BigToe,

Great to see you've joined the DIY sub posse. As far as i'm concerned, it's the only way to go.


Starkiller,

DT300 and most (probably all) sub amps are OK at 4 Ohms, so no problems there.

You probably know about this kind of stuff already, but you could model your sub using software such as WinISD, which can be downloaded from here ....

http://www.linearteam.dk/

Regards

[Starkiller]

thanks for the info, Ive got a data sheet with the sub which suggested some sizes, but i had to calculate the port manually from some equations i found in a car hifi book.
some that progarm will help
those amps look just the job, looks like ive found a project

thanks again

Starkiller,

No problem. There are plenty of people around here willing to pass on their knowledge/experience, so just ask if you need any help.

Regards

Hi Starkiller, obviously I can personally recommend the DT300 amplifier, but if you can stretch that little bit further I would suggest you take a look at the British Sub Bass (BSB) amps available from BK Electronics.

The DT300 is good, but I had to send my first one back because it went pop for no apparent reason (I had only just turned it on and there wasn't even any music playing). The second works fine, but it has a tendancy to cut out when really pushed (specifically with mid-bass). The DT300 is based on Class D technology (the same as most car sub amps) and is supposed to stay very cool, but I can tell you first hand this is not the case. I've had this amp so hot you could fry eggs on it. From what I've heard the BSBs are built so much better and technically go lower too, if infrasound is your thing

I'll be going for a BSB300 or 500 for my next project I think.

[alextgreen]

WOW, seriously impressed. What was the build time like?

Thanks

There was about 6 hours in the main structure of the cabinet and about 15 minutes of soldering and fixing. Not sure on the finish, I just handed the box over and got it a few days later.

Well done ! There's nothing like the satisfaction of hooking up something which you have built yourself.
I too am a Shiva convert after owning a sucsession of Yamaha subs.
Enjoy

Originally posted by BigToe
[B]
First, here's a graph of how it models in Bassbox Pro:

Bassbox Pro, can you give me some details on that software please.

Hi Taz,

It's full name is Bassbox 6 Professional and it's the best program I've come across for designing cabinets.

I'll list a few of the best features:-

Built in database with thousands of drivers. Every so often they release an update on the site. They now have pretty much every Adire driver too. If you are inputting the driver details yourself, any missing data can usually be calculated or estimated by the program.

It will tell you whether the driver is probably better suited to a closed or vented application.

It supports sealed, 2 types of vented, 3 types of band-pass and also PR enclosures, with 17 different cabinet shapes.

It can suggest up to 3 different box sizes for an optimal response curve if you want, or you can design the box to your own dimensions. It will also suggest port tuning frequencies and lengths etc. for the optimal curve.

It does loads more too, such as several different graphs from maximum power output to cone displacement (for checking whether the sub will bottom out at any point), and it also lets you compare several designs to each other.

The only downside is that it isn't free.

For more info, visit their homepage :- http://www.ht-audio.com/

[ReTrO]

Where did you buy your copy from BigToe?

Thanks for the info

Originally posted by ReTrO
Where did you buy your copy from BigToe?

I didn't buy it, I borrowed it from a friend

According to the site though, it can be bought from Performance Light & Sound Ltd - http://www.performance-ls.demon.co.uk/

There is a "lite" version for a fair bit cheaper, but I am not sure how it varies from the Pro version.

[stuthemong]

Guys, i normally lurk around here, so thought id actually post :D

V. Nice sub there mate, finally, someone has actually used some bracing

My normal residence is at www.talkaudio.co.uk , we design boxes *lots*, both for automotive, and home audio applications.

There is one guy on the forum, a true ledgend, called EFMax. He's basically a professional sub box designer - and really knows his mustard.

If any of you guys are thinking of building an expensive sub, it could be worth asking him to design a box for you. He only askes £25 or so, for 3-4 hours of his time to design one, he uses BBP as a main program, but also other fancy ass programs.

You tell him your type of room (even calculate your rooms Transfer Function if you can) - type of bass you want, SQ, deep drop etc... and he'll help you.

I have no interest in him getting work, I am just *extremely* impressed with what he can acheive. Thus far, only 1 box of the 1000's he has designed wasnt liked. EFMax built him a new one FoC. Cant say fairer than that.

If you are going to spend £200 on an amp, £200 on a sub, and £50 on wood, spend another £25 on a decent box design, so the sub actually sounds good, unless you really *know* how to use BBP. (WinISD is arse, it doesnt tell you anything about cone displacement - which is extremely important). I am yet to meet anyone who knows BBP like EFMax BTW :D

thought id share that with you.
Stu