Speakers: MUN17-3W
- Thread starter fraser.
- Start date
Here's some more info on the bass cabinets. No real science behind any of it; I just like to experiment.
The front baffle is 9mm plywood. Layered on top of that is a 18mm layer of plywood which I'll veneer with a thin (1mm ish) piece of oak. This has a cut out of 300x400mm in the upper section, which is filled with a 19mm piece of valchromat. So circa 28mm front baffle which will be heavily braced. The rear of the baffle will be coated in an epoxy resin mixture, blended with atabites for density. The sides of the cabinet are similar, using a thin 9mm shell of ply to begin with and I'm going to cross brace these with 5x sections of thin ply. Once this is done, I'll apply the epoxy resin / atabites mix into the cavities between the braces. The rear of the cabinet will be slightly more traditional, using an 18mm ply sheet but again coated with a layer of resin / atabites mix.
Volume wise this should be in line with troels' design which uses 20mm ply if I remember correctly. This will most be half ply half resin mix, to the same volume.
I'll just need to figure out how to lift it...
The front baffle is 9mm plywood. Layered on top of that is a 18mm layer of plywood which I'll veneer with a thin (1mm ish) piece of oak. This has a cut out of 300x400mm in the upper section, which is filled with a 19mm piece of valchromat. So circa 28mm front baffle which will be heavily braced. The rear of the baffle will be coated in an epoxy resin mixture, blended with atabites for density. The sides of the cabinet are similar, using a thin 9mm shell of ply to begin with and I'm going to cross brace these with 5x sections of thin ply. Once this is done, I'll apply the epoxy resin / atabites mix into the cavities between the braces. The rear of the cabinet will be slightly more traditional, using an 18mm ply sheet but again coated with a layer of resin / atabites mix.
Volume wise this should be in line with troels' design which uses 20mm ply if I remember correctly. This will most be half ply half resin mix, to the same volume.
I'll just need to figure out how to lift it...
James
Lord of the Erg\o/s
Go hard or go home, as they say.
Don't put your back out lifting these cabinets. Personally, I prefer extensive cross-bracing to mass loading, if panel resonance control is the objective. Didn't you say the woofer alone is heavier than most of the loudspeakers you'd had?
Don't put your back out lifting these cabinets. Personally, I prefer extensive cross-bracing to mass loading, if panel resonance control is the objective. Didn't you say the woofer alone is heavier than most of the loudspeakers you'd had?
That's a good point! I assume it won't matter in the (active) bass cabinet but should be avoided upstairs? They are zinc coated.
in terms of mass - i'm not sure it will actually add much compared to, say, using a much thicker sheet of mdf for example for the whole thing. It should just be massively more stiff?
I admire your project and wish I had the skills and patience to try something similar myself. Alas, I do not, and would end up only much poorer, with a pile of broken stuff, and likely with many swears occurring along the way.
I've put this thread on watch and am looking forward to the pics at the end.
All the best for the remainder of your build.
I've put this thread on watch and am looking forward to the pics at the end.
All the best for the remainder of your build.
Go hard or go home, as they say.
Don't put your back out lifting these cabinets. Personally, I prefer extensive cross-bracing to mass loading, if panel resonance control is the objective. Didn't you say the woofer alone is heavier than most of the loudspeakers you'd had?
Hi James, I'm not sure if I explained this very well but the main intention of the cabinet was to make it as stiff as I possibly could, rather than high mass. Hence the thin ply (9mm) being used almost as an outer shell. The use of atabites is actually quite sparse too, I'd suggest maybe one 7kg tub spread between a whole bass cabinet. The main cabinet material is basically epoxy resin other than the front baffle where valchromat takes over as I like the look of it.
James
Lord of the Erg\o/s
Hey there, Fraser. In that case, I think more bracing will serve your objective much better.
Next up I need to find power amp / amps to drive the m/t boxes. Preferably these would sit either on the desk (need to be tiny) or be situated near to, or possibly be attached to, the speakers.
I have an smsl su9 currently, so it might be an option to swap this for an integrated with digital (usb) input and keep the box count down to 1.
I think these should be an easy load ( ok impedance; no bass to deal for with)...
I have an smsl su9 currently, so it might be an option to swap this for an integrated with digital (usb) input and keep the box count down to 1.
I think these should be an easy load ( ok impedance; no bass to deal for with)...
cabinet materials arrive tomorrow! It'll be like xmas.
Unfortunately I have well and truly knackered my back... i'm on a collection of drugs which are doing well at keeping me asleep but that's about it... a few trips to the chiropractor should hopefully mean i can get started sooner rather than later.
From looking at the collected mountain of stuff sitting in the office i'm sceptical i had quite enough, so i've stocked up on some more resin and atabites...
Speaker Plans : £90
Woofers: £1,147.90
Mids: £381.71
Tweeters: £984.35
Ply / valchromat: £469.61
Wood glue: £18
Atabites: £35
Epoxy Resin: £75
Sound deadening sheet: £28.99
Big rubber feet: £13.98
Hypex 501s: £940.80
Screws, connections and cabling £54.70
Caps (cheap equivalents!) : £158.58
Inductors / resistors (as per troels): £288.29
Mid ports £7
Oak veneer £183.16
Little plastic feet for upper cabinet £3
Osmo top oil £34.99
More resin £50
More atabites 35
Total: £4,686.91
I'm also having a closer look at the possibility of making the whole upper cabinets of resin and using a charcoal pigment to get them a similar colour to the valchromat... something to consider anyway.. I'm pretty sure i could sand / polish it to a nice finish.
Unfortunately I have well and truly knackered my back... i'm on a collection of drugs which are doing well at keeping me asleep but that's about it... a few trips to the chiropractor should hopefully mean i can get started sooner rather than later.
From looking at the collected mountain of stuff sitting in the office i'm sceptical i had quite enough, so i've stocked up on some more resin and atabites...
Speaker Plans : £90
Woofers: £1,147.90
Mids: £381.71
Tweeters: £984.35
Ply / valchromat: £469.61
Wood glue: £18
Atabites: £35
Epoxy Resin: £75
Sound deadening sheet: £28.99
Big rubber feet: £13.98
Hypex 501s: £940.80
Screws, connections and cabling £54.70
Caps (cheap equivalents!) : £158.58
Inductors / resistors (as per troels): £288.29
Mid ports £7
Oak veneer £183.16
Little plastic feet for upper cabinet £3
Osmo top oil £34.99
More resin £50
More atabites 35
Total: £4,686.91
I'm also having a closer look at the possibility of making the whole upper cabinets of resin and using a charcoal pigment to get them a similar colour to the valchromat... something to consider anyway.. I'm pretty sure i could sand / polish it to a nice finish.
S-Man
StrivingON
if you are within striking distance of Leeds, I would be happy to build them. If not, hopefully you can find someone local. Probably easier than shipping bits all over and trying to explain how you want them by phone/email.
that would be kind! i'm not sure there's much to explain really; troels has provided me with some pretty pictures which i'm sure explain what needs done, i just don't really trust myself to do a decent job of it. I've hacked my way round some PCB crossovers before but nothing hand-wired.
I would provide all the components, and either some thin timber to mount them or some polycarbonate sections to make them a bit prettier. Let me know what you think! If at some stage in the future i did upgrade the caps i'm assuming it would be a case of like-for-like replacement which I should manage.
I would provide all the components, and either some thin timber to mount them or some polycarbonate sections to make them a bit prettier. Let me know what you think! If at some stage in the future i did upgrade the caps i'm assuming it would be a case of like-for-like replacement which I should manage.
unfortunately one minor hiccup... they've forgotten to send the main front baffles! I'll try and get it sorted as the rest looks fairly decent. There's a couple of voids in the thinner sheets but i'm not too concerned. The ply is basically a thin outer shell to what is primarily an epoxy resin cabinet so i can't see it being an issue in terms of strength or rigidity...
Interestingly, although they've forgotten to send the main baffles with the cut-outs for the valchromat in-lay, they've accidentally sent an extra 19mm baffle with a woofer cut out... I've double checked my order and it's all spot on so its is definitely a cutting error. It opens up an interesting question... should I make use of the freebie and have a 50mm baffle? The internal volume would be unchanged so I can't really see much downside. Here's some test fitting without the main baffle 'housing' the valchromat; just the 9mm base layer; the 18mm 'accidental' layer and the 19mm valchromat. I actually quite like it...
It's always impressive seeing how accurately these things are cut. I know they have big fancy cnc machines and so on but if I tried to attempt something like this it would look like someone had grated a tree.
It's always impressive seeing how accurately these things are cut. I know they have big fancy cnc machines and so on but if I tried to attempt something like this it would look like someone had grated a tree.