Ever think of building a Cornu Spiral horn? Now you can!

[Chaz H]

Well, I guess we tried!

Hey, has anyone tried to make a speaker out of this stuff?

1/2 in. x 4 ft. x 8 ft. Sound Choice Sound Deadening Board-717008 at The Home Depot

 

[xrk971]

Nice find on new alternative materials there Chaz! I think this can work very well as internal wall dividers in BLH's. Maybe perfect for the PANPIPE. I have thought of using acoustic ceiling tile which is more porous. This stuff looks like it might be very clean as it is cardboard waste re-used as board.

 

[Chaz H]

Yup, I think I might also give it a try. I'm thinking about abandoning the cornu for a while again and instead building MJK's corner horn from this material. Two test cabinets for $10: hard to complain.

 

[tomlang]

Link or drawing of MJK corner horn?

 

[Chaz H]

http://www.quarter-wave.com/Horns/BLH_Design_Article.pdf

to clarify, it's only a corner horn to the extent that it's intended to be placed in a corner; it's not on the level of a klipschorn as such, in case I gave that impression.

 

[prezden]

Hi guys
Here are my latest Cornu's- 22" with 24" face with W4 bamboo drivers. Hope you like them. They're sounding great even though the drivers only have about 80hrs on them.

cheers- prez

 

[xrk971]

Prez,
That's a beautiful piece of art more than a speaker. I'm glad enlarging the driver cutout holes worked out for you. Congrats.
Did you do the cover design yourself?
How does this build compare to all the rest? Is the 4 inch bamboo driver really good?

 

[prezden]

Hi X- Thanks for the kind words. The artwork is a piece I did a few years ago recycled for this project.
I'm still breaking in the speakers but they sound quite nice. I'm using an unfinished Peter Daniels kit for the amp so have 2 unknowns going at once. At this stage they seem in between the 14" and 18" ones with the smaller being the fuller sound and the 18's being a bit thin. I have just put some new W3 bamboo's in the 18 inchers and they seem a little fuller with better bass. I don't think my poor old ears are so good to really be able to judge the subtle differences.

cheers- prez

 

[prezden]

After a few week listening I think the W4 bamboo drivers sound great in the 22" Cornu's. The sound is very clean, detailed and well balanced.

cheers prez

 

[prezden]

going wireless

Can anyone offer some advice on building a pair of wireless cornu spirals? I thought to build a receiver into the 2 boxes but can't find any info on how to do it or any design for the transmitter which I would like to build into a small T amp.

 

[xrk971]

Try a Bluetooth module like this
Bluetooth Module BT-1 320-352

http://www.parts-express.com/pe/showdetl.cfm?partnumber=320-353

 

[iko]

But you need power as well, so then... doesn't look like you get rid of cables anyway.

 

[xrk971]

You need 5 v from amp power supply. Use 7805 regulator.

 

[prezden]

Thanks guys-
Could you remove the USB and add a pair of AA batteries to power the receiver?

 

[xrk971]

4 AA batts.

 

[Cal Weldon]

Rechargeables.

 

[xrk971]

But if you are powering your class D tpa3130 amp with say 12 volts, are you using batteries for that or wall wart? If you have 12v or 9v up to 35 v the 7805 is a $0.89 ic that will drop the voltage to 4.98 volts spot on. The BT uses very little amps so you won't have much heat from regulator. Easy peasy. 7805 has input output and ground. Can't be easier and never worry about batteries.

 

[prezden]

Thanks guys- I am planning on using the tpa3130 or ta2024. Either way it would be powered with a 12v wall wart.
Would the 7805 go on the board where the usb is with the leads to the battery pack connected to the 7805 pins.

 

[xrk971]

7805 is a to220 IC with 3 pins. I would wire it with flying leads from common 12 volt positive of power supply (find a tap point on amp board) and its output gives you 5 v from the 12 volt. If you use 7805 no batteries. If you use batteries no 7805 needed. Just cut the USB jack off and locate the ground and 5v supply wire and connect that to 7805 output.

 

[zayne742]

If you use one of the sure electronic amps, they usually have a regulated 5v output on the board. One of the smaller ones also had volume buttons and could be paired with a volume knob board. You could then somehow make a volume control on the boxes?