Hi fellow Cornu makersHad to take mine down for the moment because we're doing some `redecorating` So i was thinking this might be an excellent time to start on that second pair.
I was wondering how everyone is cutting their foamcore, i was using a knife and a ruler. But i was having a little trouble getting them perfectly straight, especially after cutting a few lanes there would be a few mm difference.
I get good success using a dry-wall T-square. It is considerably thicker than a normal metal ruler and thus provides a larger surface to keep the blade perpendicular. I use thin bladed "utility" knifes that I get from Dollarama ($1.25 for two knifes with spare blades). And I perform all cuts in two passes - the first cuts the top paper and half the foam, the second cuts the rest of the of the foam and the bottom paper.
Other things to consider:
* Important to keep the blade perpendicular - this may seem obvious but can be tricky with thin blades that have a tendency to bend, hence the drywall T-square.
* As soon as there is even a hint that the blade is not cutting cleanly, as noted by the foam being "pulled", sharpen it or in my case break off the next section of blade.
* Cut all the pieces in one session using the first piece of a particular width as the template for the subsequent pieces to ensure identical width.
Cheers!
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Awesome tips for the FC master Grandcalmar. I actually use 3 to 4 passes and I use a big piece of masonite (leftover back panel from a old cabinet) as my ruler. $1 utility knives are the way to go Or xacto blades for curved cuts. The key is to use the first piece as the width gauge for all subsequent panels that need to be same width. I get +/- 0.5 mm thickness variation doing it this way and it makes the box construction much better. I have been meaning to get the drywall T square!
Or xacto blades for curved cuts. The key is to use the first piece as the width gauge for all subsequent panels that need to be same width. I get +/- 0.5 mm thickness variation doing it this way and it makes the box construction much better. I have been meaning to get the drywall T square!
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More progress on the Cornu's today. Sourced some nice wire from the local electrical wholesalers and wired up both cabinets.
As I've been itching to hear them in action, this evening I did a dry run with the front baffles taped on; the driver chamber stuffed; the drivers held in place with tape; and the speakers on the floor. Even though they weren't properly sealed or correctly positioned, I was still more than impressed by the quality of the sound they produced.
Hopefully tomorrow I'll have a chance to get the PVA out and get the cabinets properly finished
As I've been itching to hear them in action, this evening I did a dry run with the front baffles taped on; the driver chamber stuffed; the drivers held in place with tape; and the speakers on the floor. Even though they weren't properly sealed or correctly positioned, I was still more than impressed by the quality of the sound they produced.
Hopefully tomorrow I'll have a chance to get the PVA out and get the cabinets properly finished
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![IMG_20140314_135029517_HDR[1].jpg](/community/data/attachments/366/366337-adcde87cf7d1512b223ddbf9d2444968.jpg)
![IMG_20140314_184328267[1].jpg](/community/data/attachments/366/366353-2aa80eca200ff9ffa6f12dacbb8b6021.jpg)
Good morning people, its a lovely sunny Sunday morning over here in Squiffyville.
I was in the office yesterday and having had a bit of a sort out of a load of old junk that I had been storing away for a sunny day I brought home with me fifteen assorted computer speakers including the Cambridge Soundworks 5.1 system. These are all old, yellowing from the sun, throwaways that I salvaged before they went to the skip (I hate throwing perfectly good stuff away).
Anyway I want to put them to good use and make up a set of foam board speakers with them. I'm up for a challenge so anybody got any suggestions?
I was in the office yesterday and having had a bit of a sort out of a load of old junk that I had been storing away for a sunny day I brought home with me fifteen assorted computer speakers including the Cambridge Soundworks 5.1 system. These are all old, yellowing from the sun, throwaways that I salvaged before they went to the skip (I hate throwing perfectly good stuff away).
Anyway I want to put them to good use and make up a set of foam board speakers with them. I'm up for a challenge so anybody got any suggestions?
Lol love to T, or should that be yes the wife would love me to
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Thanks Squiffy - answered. As you mentioned the wife and as I'm aware of her not so loving attitude to my piles I better say no...
But thanks for the offer.Regards
Got both cabinets glued up, attached pic shows the second cab last night, finally found a use for my PhD thesis after all these years, applying pressure while wood glue sets
Hopefully I'll get the drivers mounted later and then get them up on the wall. Speaking of which are there any requirements regarding distances from floor/ceiling/walls when placing the Cornus?
Hopefully I'll get the drivers mounted later and then get them up on the wall. Speaking of which are there any requirements regarding distances from floor/ceiling/walls when placing the Cornus?
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Blaides,
Nice work and excellent use of a dissertation!
My sims show an ideal room-response when driver centerline is between 48 in to 55 in from floor. Adjust to taste but it affects the first floor bounce dip depending on how far away you listen.
You are not far from first sound...
Thanks
I'll be sitting about 3m from the speakers, so would it be better to go for the higher centreline value?
Got the Cornu's up on the wall late last night so didn't get much of chance to listen to them before the wife complained that she was trying to sleep
.But from what I've heard so far though I'm very impressed with the sound quality coming from a 3.5" driver in a foamboard enclosure. The build process was really fun too
. Hopefully I'll get some time to listen to them more later and post some pics/videos.
Now I've just got to get my new Yuan Jing 'Blue Board' TPA3116D2 amp up and running to drive them. I'm struggling to source a DC socket that can handle the 19V/5A laptop supply I'm going to use as a power supply. All the ones I can source are rated for 12V
.
Blaides,
Nice going there - I know how it is to finish a speaker at night when all is asleep. You won't be disappointed. Looking forward to some pics.
Re the PS for the amp: 12 volt can work fine if you don't need the full 40 watts. You can use an old laptop 19 volt brick SMPS - 3.5 amp is enough for most uses. They can be ordered new for circa $8 (Amazon, NewEgg, etc). Probably different online retailer in UK. I just got my Ybdz 2.0 tpa3116d2 from Aliexpress yesterday. It was cheap at $13.50 ea but took 2 months to get. Sounds great though. I am using a 19v 3.54 amp SMPS from my last laptop.
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Nice going there - I know how it is to finish a speaker at night when all is asleep. You won't be disappointed. Looking forward to some pics.
Re the PS for the amp: 12 volt can work fine if you don't need the full 40 watts. You can use an old laptop 19 volt brick SMPS - 3.5 amp is enough for most uses. They can be ordered new for circa $8 (Amazon, NewEgg, etc). Probably different online retailer in UK. I just got my Ybdz 2.0 tpa3116d2 from Aliexpress yesterday. It was cheap at $13.50 ea but took 2 months to get. Sounds great though. I am using a 19v 3.54 amp SMPS from my last laptop.
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