Project : Relax-12 (Subwoofer)

[Mat-Moo]

Based on the Relinquish-12 project http://homepage.ntlworld.com/jackie..../subwoofer.htm and also on the RTP-12

(Photos at http://matthew.augier.info/?album=%2FDIY%2FRelax-12&)

1) Pict0752 - First of all I wanted to base it on the 22mm mdf but I'd been unable to source any from my local sheds, so I used the plans on the Relinquish page and recalculated them to 18mm and set of down the shed
2) Pict0754 - Picked up the 18mm sheet and took it to the saw mill in store and got the 2 major cuts done (took the mdf into 3 strips making it easy to transport as per pic 1)
3) My calculating the cut edge I was able to mark out and cut the various panels using a standard circular saw
4) Pict0755 - Dry fit to see how it all goes, not too bad considering the cuts are not all 100% accurate (1mm here and there!)
5) Pict0765 - MDF has been pre-drilled and screwed together (Screwing is not the best idea with mdf but I needed to work out what needed trimming etc. and it was the easiest way to work) Most ofthe mdf is slightly over so that is can be sanded flat, and screw holes will all be filled
6) Pict0766 - Shows internal brace, holes cut with a jig saw so not perfect, will use rotozip with circle cutting attachment for main speaker hole. Various other bits ordered in from CPC including hard cover (stop kids fingers) and spikes etc.

Not having much luck with BK Elecs at the moment, no answer and no replies to emails, so may source the Amp/woofer elsewhere. I'll try and keep you uptodate

[Taz]

Originally posted by Mat-d-Rat


Not having much luck with BK Elecs at the moment, no answer and no replies to emails

There's a surprise!

[Taz]

Just a few comments......

Originally posted by Mat-d-Rat


1) Pict0752 - First of all I wanted to base it on the 22mm mdf but I'd been unable to source any from my local sheds, so I used the plans on the Relinquish page and recalculated them to 18mm and set of down the shed

Oooh...18mm is very pourous do yourself a favour now and seal all the inside surfaces mate.

4) Pict0755 - Dry fit to see how it all goes, not too bad considering the cuts are not all 100% accurate (1mm here and there!)

1mm..thats very good! we aim for a +/- of 0.5mm with the CNC cut RTP stuff before sanding.

5) Pict0765 - MDF has been pre-drilled and screwed together (Screwing is not the best idea with mdf but I needed to work out what needed trimming etc. and it was the easiest way to work) Most ofthe mdf is slightly over so that is can be sanded flat, and screw holes will all be filled

Screwing in the end of MDF is not a good idea, be careful it dosen't blow..Sanding flat eh? now there is a job!

6) Pict0766 - Shows internal brace, holes cut with a jig saw so not perfect, will use rotozip with circle cutting attachment for main speaker hole.

What thickness is the internal brace MDF? we use 30mm..If you have used 18 then may I suggest another the same and laminate them together to give 36mm...the holes dont have to be perfect either no ones going to see them..(our holes are coz they are done by CNC :-) )

[Mat-Moo]

Thanks for the input - What do you suggest sealing with? I was going to paint it with a few coats of white paint once sanded (Horrible job!). Brace will now be doubled as sugested, and yes screwing into side is not a good idea, but once glued that should remove most of the pressure from the screws.

PS - Any idea on best way to contact BK?

[Taz]

Originally posted by Mat-d-Rat
Thanks for the input - What do you suggest sealing with?

PS - Any idea on best way to contact BK?

Get yourself down to DIY shop and get some MDF sealer the real thing or if thats not poss. how about a few coats of varnish..this is for the inside only ok?

Contacting BK?? God knows! keep phoning they will pick up in the end but I have had nothing but hassle trying in the past.

[Mat-Moo]

WOOT! Got through to BK today (third attempt, and I was on the call back list today apparently??!!), but they are waiting for Sub panels so won't be getting it till mid/end next week... Gives me time to finish the box I suppose, but I don't really want to cut any holes till I know the exact size of the panel / woofer (If anyone has the BSBp 100/8 panel or BSBL 12-100 exact sizes I would be VERY grateful!)

[ReTrO]

Originally posted by Mat-d-Rat
(If anyone has the BSBp 100/8 panel or BSBL 12-100 exact sizes I would be VERY grateful!)

If Taz hasn't got them to hand I might have them on my PC at home.

[Taz]

Originally posted by ReTrO
If Taz hasn't got them to hand I might have them on my PC at home.

sorry I dont think I do have them... You can always phone BK, but be warned I did and got a wrong size for the RTP-XR

I would wait untill the parts are in your hands better to be safe than sorry

[Mat-Moo]

Ok as you say better safe than sorry though. I got the second baffle made today and glued together. Also glued the bottom, back and sides, will probbaly glu baffle in later. Thinking of mixing some pva glue and water to paint and seal the inside of the sub - don't see any reason why that wouldn't work.

[Taz]

Originally posted by Mat-d-Rat
Thinking of mixing some pva glue and water to paint and seal the inside of the sub - don't see any reason why that wouldn't work.

Dont worry about the water! MDF + water is very similar to Titanic and ice or ReTrO and girls ie: they do not mix.

Just paint the inside with PVA on its own if you arn't going to get MDF sealer.

seal all the joints with caulk internally as well!

[shodan]

Originally posted by Taz
MDF + water is very similar to Titanic and ice or ReTrO and girls ie: they do not mix.

MWAHAHAHAHAHA!! HA HA HA!! HEE HEE HEE!!! HOO HOO HOO! MWA HA HA HA!!!!!!

[IronGiant]

Nice work Mat, I'm glad you were able to use/modify our Relinquished cutting plans, also pleased that they worked

Rather than just do a square cut out for the amp panel I waited until I had it , then worked out a cut out that took out as little material as possible and still allowed the panel to fit; to keep as much rigidity as possible.

I cut a hole for the driver with a router/circle cutter and the damn thing didn't fit so I had to hand finish it, so i'd rather not quote you figures that might mess up for you.


have you thought about a finish yet?

Dave

[Mat-Moo]

Thanks - I am going to wait for the driver and panel to turn up, better safe than sorry as they say. ALthough I've never used the dremel with a circle cutter before so may practise on a bit of scrap. Finish will be via Beech fablon, although it's lighter than I wanted, but will ahve to do for now. There is also going to be a hard 12.5" grill over the front (from cpc) to keep little kiddy hands out of the way! BTW did you countersink the panel/driver at all? I was going to rebate the panel in to help get a better seal etc. and look neater, not sure about driver though, especially as the cover will stand proud and hide it anyway.

[Mat-Moo]

Ok, lateest pics no uploaded to http://matthew.augier.info/?album=%2FDIY%2FRelax-12&
Pict0808 - as advised internal brace has been doubled
Picyt810 - I also decided to add a 1" front border for the front panel to have a better fixing area to the main part of the sub/spread the load (made out of scraps)

I'm just waiting for the glue to harden and I'll try and give it a interioir coat of varnish, also appologies for my slow site, having some server issues at present.

Also as a secondary part I've made my own sub cable, using a couple of connectors from CPC (Although I had to drill them out to 7mm to allow cable ends to slide easily, and some 75ohm satelite cable (Had it spare lying around)

[IronGiant]

Mat, in the RTP/Relinquished design the driver should be rebated because the front panel is made out of two pieces of MDF sandwiched together. The outer has a hole cut in it so that the driver can sit within it and the driver is screwed/bolted to the inner. So our front panels are 44mm thick and yours should be 36mm.

Hope this makes sense,

Dave