menace

Its not the really clean stuff(as i did score a bunch of quarter sheet off cuts of that and it was really tidy faced)... dont know how much that would be...

The story is not so pretty down here, im in new zealand and bee dub is in australia i believe. In nz 18mm birch is nearly 130usd per sheet and the story will be similar in ozy... economy of scale and shipping exspense, it is what it is! Hence a lot of guys down here trying for easier on the pocket options!

Just to make things clear about the mdf, mdf and baltic birch are the same weight by volume just the baltic birch is far stronger and much more durable. I did make an othorn out of mdf and it performs surprising well but i only did it as a kind of a mock up, id say it will be around a while as it stays on the property, i wouldnt expect it to last too long if it were lugged around to gigs and so on. I have got as couple of pieces of australian plantation hoop pine ply(aracauria cunninghamii, nice trees!) laying around and that stuff isnt too bad assuming the price was right. I think birch is the right stuff for the job. I saying that many have had success with other woods as well.

I know some people have had issue with t nuts spinning. Here is what i did to ensure against that, small screws and a bit of epoxy I had on the shelf. Fairly crude but simple and will be effective..

FWIW, i need to report back again with how this has turned. I continued to use this solution and after initially hearing some vibrations at close range on the first one of two listening sessions I have not noticed it again since. SO i believe the solution is good although considering there were vibrations initially its is not a solid solution with out some modification like thicker wire in the mesh and perhaps attempting to fasten both ends on the mesh where i I only fixed one end of the mesh and the other end is kind on jammed into place against some pieces of thick ridged felt type polyester type acoustic paneling I had laying around(I dont have pics unfortunately) the sharp ends on the cut wire found them selves fairly sturdy homes.

I need to comment on this again! I threw a wee birthday celebration party for my self over the weekend and ran the subs right up until the limit at times. I didn't go out of my way to take extra observations but i cant say i ever heard the vibrations this time around( and i was very close to them at times). I defiantly did hear noises from them another time though. So I am guessing this solution can work, perhaps with a heavier gauge wire mesh and/or a better fixing technique.

I need to report back on how this solution turned out. Some vibration! So until I play around some more it should be noted that this didn't work.

Good to hear they are working well with 100hz LPF. Does that mean you wont need the kick bins anymore? What are the box things under your tops?

Thanks for replying that answered my questions...

Ultimately this has to come at a cost to efficiency and/or extension..... On another note, do you think you will ever finish the pale-horn design/drawing? Or do these hybrid designs totally supersede your interest now?( will be interesting to see the final analysis ie your measurements of an SKram loaded with 21sw/21ds vs the old othorn measurements). Also this may have been covered somewhere else but whats the theory to these hybrid designs, obviously there is bass reflex... but how does the horn part work together with the bass reflex? There is the compression ratio working as a cushion against the driver? What about the horn length, how is that fitting in?

This is what I have come up with so far. Was thinking of fixing the mesh at the end of the mesh that's easy to get at with screws and washers and the other end will kind of grip into the wood by the sharp ends it has from being snipped to size. The mesh is about 1.6mm strand size, its easy enough to bend by hand but will still have a bid of tension on it from being pulled into position by the screws. What do you guys think? Could it vibrate perhaps?

how much is the mod? I can't help but think if the water cooling was a thing then they would be offering a solution them selves(powersoft/b&c)? And how did you go about contacting powersoft directly for this? They have quite a few OEM things that are pretty interesting!

Timon. I am interested in your cheap source for ipal and mod? Active cooling, does the lag between coil/air/magnet allow this to be practical?

Ah in side the box further down the port/horns. That sounds like quite a good idea as wouldnt need to bother with asthetics and it leaves the mouths to be used as handles.... I'll give that some thought....

What do people think about speaker grills for these? It would seem they would alter the tuning some? Any thoughts?

Not that I can see. At least not any more. If it's true I trust you only reported after purchasing....

I would though say that less plies will almost always be worse! As for Baltic vs other birch, this should be an important distinguishing factor and having not seen the other birch ply i would imagine they should not be compared. Wikipedia list 50+ species with in the genus and imagine there will be chalk and cheese like differences among them. Growth rate according to geographic location and the correct species will mean everything!

Pinus radiata plantations down her are big business and there is about four mdf plants largely for export and at least two are owned by the Japanese. I am though surprised that Europe buy economy of scale alone doesn't at least equal our prices....... Anyway going a bit too much off topic now I think. Sorry OP....

It has to be said that you Europeans are very lucky being so close to the baltic. The story in new zealand is very different, 18mm mdf 25 euro and 18mm BB ply 110 euro(2440x1220 sheets).

Baltic birch is the only option. Its so strong, I made a small sub box out of 12mm and once i put a few braces in it was easily strong enough.

Scale? 1/16 I think I recall my cnc guy saying...

I trade in MDF so it kinda free. It holds up to a good chunk of power though I was quite surprised and no that cabinet is not for moving around. These next cabinets will be made of the birch ply certainly. Thanks for the good explanation regarding damping too... .

Okay, got ya. Perhaps my net loss understanding pertains more to tapped horns..... Thanks for the reply. Ill be getting a couple of these cut this week probably not built to the week after though. looking forward to it! Will be interesting to do side by side listening to the othorn made out of mdf I have.......

Ricci, I see you added egg carton style foam to the SKhorn's. Did you ever measure to see what improvements this adds? Is it necessary? What your thoughts? I was always under the impression that adding stuffing to subs was usually a net loss in overall output?

Thanks for the reply, I see a few pages back you also asked similar questions with not much reply. I think you are right though you should build another pair for 3 per side;-). Should of got the 8 ohm drivers ha? No just go 4 per side!..... hmm still not the right hieght;-/.... 6 per side>presto! I have building a pair of these at the top of my to do list at present and am just working out my adjustments/deductions/add-ons for my cabinets hence the questions. What about the weight balance it looks pretty much 50 50 front/rear(im thinking about pole mount position for top box), was that your experience lifting them? Also what about the hatch, I see its a little smaller than the othorn. Was there plenty of space getting the driver in and out as I intend to do that slightly differently requiring it to be a little smaller. How'd this weekends show go?