[Ash_May]

I thought it would be good to share the build process of my Rythmik DS12 with you lot, and ofcourse appreciate your comments along the way.

This is a servo sub, employing 'similar' technology and principals as Velodyne DDs.


I have been reading up on subs on this forum for a while, and subsequently became very close to buying a BK Monolith / SVS. But I didn't, for these reasons:

- I don't need huge* SPL, and HT is secondary to music reproduction for me

- I wanted something that wasn't too big, but didnt want to trade much extension

- Always wanted to do a DIY speaker project.

- The best 'quality' bass I could afford.

The last point may be slightly contentious, as I have never heard an SVS ultra, BK monolith or indeed a Rythmik. Like many people here, I have had to put my faith in members on various forums, and hearing favourable comments about the Rythmik over the likes of SVS and JL, (not forgetting Ilkka's sub tests) I decided to take the plunge and order the kit from:

Rythmik Audio 12" servo subwoofer " DS1200 Custom Installation subwoofer

Delivery takes 4-6 weeks, and as I have recently ordered it, I'm in for a long wait. At this point I should credit 'milesr3' with his excellent thread and link to his build - http://www.avforums.com/forums/home-...ealed-56l.html , great for reference - thanks!


So to ease the pain of waiting so long, my build commenced.

Plans are gleaned from Rythmiks website, the 2 cubic ft (56L) enclosure to suit the 12" driver and 370W servo amp.

I had originaly decided to rotate the entire enclosure to create a forward firing design, and relocate the amp plate to opposite the driver. I built a 3D model to proof it first -

After messing around with the cut 18mm MDF sheets, I reverted to the original plans for a downward firing version...

So, first off the panels were and braces were cut. Sorry about the picture quality!

Then the gluing process begins. Screws could be used to hold the glued panels together but wouldn't really give you more in terms of strength, this is just stuck using PVA and heavily clamped.

Note extra corner beading (above) for added strength.

Also the 4th side panel is glued on (not shown)


The enclosure has been very easy to make so far, there are just a couple of edges that sit proud at the top that will require sanding / plaining back so the last panel (top) can fit on flush...

Then comes the major sanding and addition of legs. The corners will eventually be routed too. Not too sure about putting spikes on the feet though

I will update this thread with more pics as and when I have made more progress

Ash

[leedude03]

Nice work so far, and you can never have to much bracing trust me enough is never enough if you know what i mean.
Look forward to seeing the progress of this project.

[Deadringers]

yea nice work! looks very professional so far!

[Ash_May]

Cheers for the comments, with the bracing sinside it seems really solid. Got some BAF wadding on order to line the inside too.

Hopefully I can make some more progress this weekend, should get the feet on and start the sanding and router the outer corners...

[milesr3]

Ooh that brings back happy memories

Looking very tidy so far. Hope the driver and amp plate don't take too long to arrive and please keep use posted with your results.

The new amp plates with Parametric EQ look very interesting - I could have done with one of these myself. Also the 600W amp plate looks verrrrry interesting. You could build a very serious sub with one of these and a DS1500 driver or a pair of DS1200s in a cylinder

That said, I'm still totally happy with my 370W DS12s. It provides all the bass I need and now I have it properly equalised is sounding just lovely. I could never go back to just 'full range' speakers again.

[Ash_May]

I hope I'll look back on this with happy memories too! It's good fun though, and quite satisfying seeing it take shape. I will certainly keep this updated.

Yeh, I wondered why your amp didnt have the PEQ - I didnt realise this was a relatively new addition. The 600W plates are probably out of my price bracket at the moment though, and to be honest the current exchange rate makes my build a fair bit more expensive than yours - I wish I had the perspicacity to do it when you did!

I really can't wait to get this up and running...I may have a little surprise of a finishing touch at the end too

[micb3rd]

Looks like a strong build!

Next time you build look at polyurethane glue.

Polyurethane Glue

PVA / Normal wood glues don't come close to decent polyurethane glue, poly glue foams up so fills gaps and grip the wood together rather than push wood a part like PVA, gripfill or silicone.

I have done many boxes with PVA and yes it does work but there is better out there.

[Ash_May]

Thanks for the info, I will look at using that next time

Here's a bit of an update from over the weekend; the weather had been nice up until this afternoon when it hailed out of nowhere. Still managed to get a bit done though.

Here it is pre recent work:

No top or legs.

Top goes on - clamps and weights pushing it together

Extra glue on the inside

Next stage was glueing the feet...

Which look like this from the underneath:

They sit at the very corners of the box. I have inset spike fixing points which gives me a few options if the sub ever sits on different types of flooring. They sit lower down so it doesn't look too out of place if spikes are being used on a hard floor and the outer legs are raised up.

I have started the sanding process, then routering the vertical edges (including legs) to create an elegant single form (hopefully ).

It's resting on a mdf base indoors so the legs dry completely square..

Once the corners are routered and the whole thing is sanded to a good standard, then I will give it 2-3 coats of Shellac (sanding between each).

Then comes the primer and paint

[milesr3]

Looking very tidy still and looking forward to seeing how you finish it off.

I had a demo of some ludicrously expensive Linn system in a shop on Saturday and was shocked how much worse the bass was than from my humble home-made Rythmik. I think you'll be pleasantly surprised...

[Ash_May]

That's reassuring to hear. Which Linn sub was that? Even though the exchange rate has made this more expensive than I would have liked, it still seems a comparative bargain.

Really can't wait to get this running. Out of interest, how have you EQ'd yours? BFD?

[milesr3]

There was no sub, it was purely a stereo setup with a Linn Akurate DS running through a set of fully active floorstanders. Sounded boomy and nothing like the level of clarity and texture as the Rythmik, but probably more to do with the demo room than the speakers.

I have EQ'd mine with a BFD. I originally had an 1124dsp, but I now have an FBQ2496. It takes a little time but makes a massive difference.

[Ash_May]

Made a bit of progress this sunny weekend.

Firstly, my driver and amp have arrived! I was quite shocked to see a letter from Parcelforce last Thursday. I only ordered on the 2nd of march, so thats about 2 and a half weeks, pretty good going all the way from Texas.

The quality of the amp and driver is immediately apparent when you pry them from the packaging. Needless to say they were both test fitted in the enclosure so i can continue finishing the box with a renewed haste...

So the corners of the box have now been routered to give a nice radius, and its been throughly sanded throughout. 3 coats of white Shellac, (sanding between coats) seals the spongelike edges of the MDF prior to primering. Here the spikes came in handy to raise the whole thing off the ground to get an even shellac covering. The MDF is now hard and smooth.

The next stage will involve primer, sanding, more primer and a little bit of filler. There are a couple of blemishes I need to sort out that will become immediaetly apparent when painted if not sorted now.

Paint will be a gloss black, sanded flat, then using a cutting compound to acheive a mirrored black finish. Well, thats the plan anyway.

See pics...

And not forgetting this...Aluminium badge will eventually finish it off. I'm going to spray this black, then rub it back to leave black in the letters, this will hopefully complement the gloss black enclosure finish.

I designed it, but the milling was a favour from a guy at work, for whom I am eternally grateful! got my fathers name on there too, he's given me alot of help and guidance. Cheers dad!

[Ash_May]

Weekend update...

Got the primer on, which highlighted some imprefections, which were fillered and sanded.

Primer was flatted off with 600 sandpaper, then 2 500ml cans of gloss black. Pics inside...

Badge sprayed and rubbed back:

Next step will be flat the black off, and use a cutting compound to acheive a nice shiney finish. Then maybe a clearcoat and repeat the process, depending on how it looks.

[IronGiant]

Nice job Thanks for fixing the links in the previous post, I was wondering what badge you were talking about

Dave

[Stephen R]

Amazing! When is the review coming??

[Ash_May]

Originally Posted by IronGiant

Nice job Thanks for fixing the links in the previous post, I was wondering what badge you were talking about

Dave

Thanks Dave, it seems direct linking to Picasa causes some unpleasantness

Originally Posted by Stephen R

Amazing! When is the review coming??

Thanks Stephen, it's going to take a good few weeks unfortunately. The gloss black takes 2 weeks to fully harden before I can flat it off. I don't want to rush it and bodge it up at this stage.

I've never attempted a 'piano' gloss finish before, but here is the process I will be roughly following. Sounds like alot of work but it should all be worth it in the end!

[suniil]

Excellent build ash so far! Keen to see piano black on the box.

That guy on DIY forum is very popular on AVSForum, but not sure he appears here in different name or not!

[milesr3]

Still looking good!

Have you had a chance to fire it up yet? Will be interested to hear what you think of it.

Those instructions on producing a piano black finish remind me of the time I once spent 80 hours polishing an old M5 I owned: http://i142.photobucket.com/albums/r...3/IMGP0766.jpg

Never again! At least you've got a more uniform shape. Should look very nice indeed once done, although you'll be forever cleaning it but won't want to touch it in case you scratch it.

[Stephen R]

Originally Posted by Ash_May

Thanks Stephen, it's going to take a good few weeks unfortunately. The gloss black takes 2 weeks to fully harden before I can flat it off. I don't want to rush it and bodge it up at this stage.

I've never attempted a 'piano' gloss finish before, but here is the process I will be roughly following. Sounds like alot of work but it should all be worth it in the end!

I'm blown by your patience and wood working skills. This is definitely a package I would love to get myself. Unfortunately I'm studying and often moving around, so not possible at the moment.
Make sure you check they both are working (amp and driver) if you haven't done so, even if the enclosure isn't finished.
Please keep us posted

[Ash_May]

Originally Posted by suniil

Excellent build ash so far! Keen to see piano black on the box.
That guy on DIY forum is very popular on AVSForum, but not sure he appears here in different name or not!

Cheers! I'm not a regular on AVS, but it just shows what you can do at home with a bit of care, effort and knowledge!

Originally Posted by milesr3

Still looking good!

Have you had a chance to fire it up yet? Will be interested to hear what you think of it.

Those instructions on producing a piano black finish remind me of the time I once spent 80 hours polishing an old M5 I owned: http://i142.photobucket.com/albums/r...3/IMGP0766.jpg

Never again! At least you've got a more uniform shape. Should look very nice indeed once done, although you'll be forever cleaning it but won't want to touch it in case you scratch it.

Not fired up yet, I wanted to get the spraying done before I installed the BAF wadding, incase I got paint on it and it went hard. During the 2 week I may aswell get it up and running...well i can't wait any longer!

Nice finish on that M5 but 80! hours now I'm worried whats in store! Yeh I'm a bit concerened about scratches which is why I may have to go for a clearcoat ontop.

Originally Posted by Stephen R

I'm blown by your patience and wood working skills. This is definitely a package I would love to get myself. Unfortunately I'm studying and often moving around, so not possible at the moment.
Make sure you check they both are working (amp and driver) if you haven't done so, even if the enclosure isn't finished.
Please keep us posted

Well, I'm going to try and get it fitted after work for testing. I'll post some initial thoughts. Once the thing is completely finished i will post a comprehensive review.

[Moonfly]

Hi Ash,

Hows it going, I know its only been a week since your last posts but you just cant keep us waiting. Gotta see that polished piano gloss black finish , I'm hoping anyway .

Its going to took top class finished off with your metal badge, and the driver and amp in place.

Cant wait . . . . . still lol.

[leedude03]

I see you are nearly there and i must say its looking good, the gloss black finish is worth the wait, it takes an age to do but does look realy good, a link to the 2 i built just to give you an idea of how they look.

http://www.avforums.com/forums/home-...0-attempt.html

[Ash_May]

Originally Posted by leedude03

I see you are nearly there and i must say its looking good, the gloss black finish is worth the wait, it takes an age to do but does look realy good, a link to the 2 i built just to give you an idea of how they look.

http://www.avforums.com/forums/home-...0-attempt.html

Wow, that's a great gloss finish... Good work


Well I havent updated for months...and the truth is I haven't done anything for months! Once the gloss black was on I fitted the driver and amp for a quick test, which turned out to be a 3 month test more on the sound quality in a moment.

Once the driver and amp were out, I masked off for several coats of clear lacquer - this took 2 weeks to harden before it could be flattened off. Rubbing down was done with a 2000 grain 3M paper (wet), until the surface was a dull mat. There are still slight pits in the surface - I didn't want to rub it down too far, because I didn't go crazy with the layers of paint or laquer.

After the sanding the surface you start to see a more defined, but hazy reflection. Next job was using a rubbing compound, applied with a cloth, which has a finer cutting action than the 2000 sandpaper. This really brings the shine up and gives a far clearer reflection.

See progress below. Next stage is - possibly one more pass with the cutting compound, then car polish, ready to fit the driver, amp and badge.

I had been running it for around 3 months before I decided to finish the box. Unfortunatly, I had been running it in the corner, which is just about the worst place as it causes awful peaks in certain listening positions, but I'm having to stick with it until we move house (hopefully) next year.

Despite this predicament, the Rythmik instantly impresses. TBH, going from a £200 Sony sub, it was hard not to. The things that really stick out are speed, depth and texture.

For example, there is hardly any 'roll on' or 'roll off' to notes, and the speed in which it changes notes is really superb. People often talk on here about depth and SPL, but what the Rythmik does particularly well is imbue a texture to the bass, so it sounds like it has come from the instrument, rather than a monotonal noise. What's interesting is what you don't hear - the bass seems so clear and transparent, which is probably down to the servo feedback loop.

I've just been fiddling with the PEQ, but once it get this thing properly sited and response flattened (Anti-Mode maybe?) I think the best is yet to come.


Really enjoying the DIY approach, so much so I'm considering replacing my Epos fronts with some DIY jobs next year. Much research is needed though!

More progress to follow.

[g1ng3r]

Looks great! Congrats

I want to do something like this.. I bet it feels good once it's done, to listen to your own creation.

Good luck in future projects mate, I will definitely be keeping an eye out!

[tony brazao]

Nice build, very interesting thread. It would be very interesting to see some test data for this sub compared to an off the shelf unit like a monolith.

[Ash_May]

Thanks

Yes it's very satisfying indeed to say 'I made that'. g1ng3r, get yourself over to diyaudio.com if you havent already, some incredible projects on there.

Cheers Tony, I need to invest in an spl meter etc and start experimenting. Also an EQ device - I'm not sure to go down the BFD route or the Anti-mode

[Russell.Williams]

Originally Posted by tony brazao

Nice build, very interesting thread. It would be very interesting to see some test data for this sub compared to an off the shelf unit like a monolith.

Monolith, DS12. Do bear in mind that one is near twice the size of the other and so will be untouchable low down and at high volumes. Instead note how the DS12 stays very clean above 50Hz and has vanishingly low group delay (consistent phase response). Set up right, it'll be awesome with music.

@Ash_May - I'd take a look at measuring your current response to see what, if any EQ device may best suit your needs. Super build by the way and thanks for keeping us up to date. It's the inspiration I need for the autumn.

Russell

[milesr3]

Originally Posted by Russell.Williams

It's the inspiration I need for the autumn.

Act fast while the pound is still high against the dollar

What are you thinking of building then? You're still very welcome to borrow my DS12s if you want to audition one in your own home, gauge how it compares with others you've listened to and consider the 15" driver and cabinet options (assuming you're not sick of continually reviewing new stuff).

[Russell.Williams]

A pair of 75L sealed, Acoustic Elegance AV-15X subs each powered from an 800W channel of a Behringer EP2500 amp.

I've been watching the dollar closely and whilst it's not a weak as it was when Ash_May bought his Rythmik, at least it's heading in that direction. The overall price has has dropped by about £30 since I started planning this a couple of months ago.

Russell

[milesr3]

Well that ought to give you plenty of headroom

Are you going for a piano black finish to match your XTZs?

I ordered something from the US yesterday and got 1.6 dollars to the pound via Paypal, which was pretty good.