Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 7:05:15 GMT
The resin is now dry and the cabinets have a much more solid feel and sound when you rap them. Today I will try to clea off the spillage I made when slopping in the resin. Another lesson learned: mask the cabinets when using this stuff. More lessons too: acetone wipes off polyester resin. It wa s a couple of hours before I discovered this,,hence today's clean up operation. Finally, if building with these cabinets, don't run the carbon fibre too near the top or the lid won't fit on! Luckily I realised this when the. Carbon fibre was dry but soft and I was able to trim it off easily.  |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 7:06:13 GMT
|
|
|
|
Post by ChrisB on Apr 10, 2016 7:44:47 GMT
I see from the photos that the lid has an internal lip that locates into the top rim of the main box. How are you planning to close the boxes up Andrew? Will you just glue them up, therefore sealing them for good, so in future, access will have to be through the driver holes or do you have some other plan?
|
|
|
|
Post by brian2957 on Apr 10, 2016 8:08:32 GMT
Fantastic project . Well done Andrew and thanks for taking the time to post the pictures and give us a running commentary of your adventures with this . Do you have a link for the boxes which you bought Andrew . They look the perfect size for this project  |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 8:47:14 GMT
|
|
|
|
Post by MikeMusic on Apr 10, 2016 9:15:49 GMT
Isobaric must be good ! I wondered about that when I saw the 2 units using the same air space Not that I'm at all biased of course |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 9:18:51 GMT
Apologies about the link above, mine were the XL size boxes (20cm) but from the same seller.
I've left the link in place for the smaller 17cm ones in case anyone wants an even smaller box.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 9:26:44 GMT
Isobaric must be good ! I wondered about that when I saw the 2 units using the same air space Nva cause the Not that I'm at all biased of course Indeed, Mike. the cube boxes lend themselves to stacking because the bevel detail on the top isn't repeated on the bottom. If your invert the lower box, it makes the whole thing symmetrical. The bottom of the box is also thinner, so doubling the mass up by putting the bases together should make it stronger. I want to re-iterate that my design input here is limited to trying carbon fibre (which may yet prove to be inadequate). The vast majority of the knowledge and ingenuity come from Richard Dunn who found these cabinets and saw the uses. He also found the bass units and recommended the tweeter to me a couple of years ago for some Cube 1s I had. The crossover values were simply lifted from several forum discussions so may also need tweaking. Nevertheless, it's fun to build, even if you are relying almost completely on other people's design skills. I really hope others will try cube shaped speakers, whether NVA, Allison or DIY because there is something very "right" about them. Nobody would listen on other forums when RD tried to explain how and why they work. Having experienced a few pairs now, I'm a believer. Whilst I don't have the technical savvy, the explanations make sense to me. More importantly they sounds back up the theory. Let's hope I can get mine sounding good. |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 9:39:36 GMT
Thankfully the resin sanded off the cabinets.  I'm off out for the day, but next up wil be deciding on cabinet finish (clear lacquer or Danish oil). I will experiment using the cut outs from the cabinets and choose the best one. I will then solder the leads and minimal crossovers. Then it's just a case of assembly. |
|
|
|
Post by Sovereign on Apr 10, 2016 10:16:02 GMT
Nice one mate good luck with the build
|
|
|
|
Post by MikeMusic on Apr 10, 2016 14:06:58 GMT
I always saw speakers as rectanguloids - if that is a word.
Then I saw Quad and electrostatics
John's favourite open baffles next
Now I see Cubes
More learning...
|
|
|
|
Post by brian2957 on Apr 10, 2016 17:23:00 GMT
So , are the tweeters forward firing and the bass units upward firing Andrew ?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 18:01:44 GMT
Yes, that's right. The idea is that the bass unit isn't trying to rock the cabinet back and forth the way a normal driver will. It's also meant to ensure the non linear higher frequency output from the bass unit is effectively rolled off because it's not firing right at you. (Higher frequencies are more directional). Ass the bass unit is crossoverless, this is meant to help it integrate with the tweeter. I hope I've explained that correctly. If not,maybe DSJR or another "cubist" can do better |
|
|
|
Post by brian2957 on Apr 10, 2016 18:49:49 GMT
Thanks Andrew .
|
|
myles
Rank: Trio
Posts: 153 
|
Post by myles on Apr 10, 2016 20:03:26 GMT
Clear would be my choice. Very nice job.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 23:20:48 GMT
Been following this thread with interest as I've had the inclination to make a set of cuboid speakers for some time but couldn't muster up the zest to do the required woodwork (already have some redundant B&W drivers I can use) So thanks for the box links - that might fire up the enthusiasm  Looking forward to reading how they sound.... |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 10, 2016 23:26:44 GMT
Yes, that's right. The idea is that the bass unit isn't trying to rock the cabinet back and forth the way a normal driver will. It's also meant to ensure the non linear higher frequency output from the bass unit is effectively rolled off because it's not firing right at you. (Higher frequencies are more directional). Ass the bass unit is crossoverless, this is meant to help it integrate with the tweeter. I hope I've explained that correctly. If not,maybe DSJR or another "cubist" can do better Many years ago there was a speaker I recall seeing at a dealers with an upward firing bass unit - above it was an inverse pyramid to disperse the sound. Can't for the life of me remember the make though  |
|
|
|
Post by ChrisB on Apr 10, 2016 23:45:01 GMT
That approach has been used and reinvented quite a lot over the years.
The last version of it that I know of which was plastered over the hi-fi press at the time was the Canon S-30 and S-35 thing along with its brethren. They flipped it over and fired downwards onto the conical diffuser though.
It's rather different from the configuration that Andrew is using though.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 11, 2016 0:01:11 GMT
It's rather different from the configuration that Andrew is using though. Yep - the absence of pyramids was a big giveaway on that score Although the principle of an upward facing bass driver is really the point I was making as this was at the time quite a radical departure Just wish I could remember the name of the one I remember though - around late '70s early '80s  ? |
|
|
|
Post by ChrisB on Apr 11, 2016 0:13:17 GMT
|
|
?