Check over my AV12 design

[phillfyspoon]

Before this gets built I wanted some advice if the design is ok im such a noob it's not funny lol

ae speakers Av12 driver
PE 500W amp

142L ported enclosure tuned to 18hz
two 4" flared ports 37.94 inches long

I plan to have a simple box design with the driver and ports on the front baffle. With the box braced heavly. I was going to buy precsion flared ports from PE and use the flared ends on some pvc pipe which will have to bend to fit inside enclosure.

If i increase enclosure to 160l the port will be 33 inches instead of over 37, better?

is this project doomed for failure or is it ok to go ahead?

stick to this or something else?

[simon5]

I know passive radiators are more expensive, but this box is large for an AV12.

It will work but it might be slightly boomy.

[phillfyspoon]

it doesnt have to be that large but ports are very long no matter what size.

I would use PR but funds very tight.

what would be a good comprimise using ports?

[phillfyspoon]

If I was to use 4cf which is 113L could I get away with one 4" flared port?

this is the design recomended so someone must of built it?

please help I have allready bought the av12

[Collo]

A four inch port with Precision port flares each end (30mm radius) is good for 17 - 18 m/sec. before you get audible chuffing.

Use a design program that lets you check peak port velocity (for example WinISD). If the velocity is higher than this, you'll need to reconsider. A single 4 inch port is usually what you use for a 10 inch driver. I suspect that you will need a pair

regards
Collo

[phillfyspoon]

Ok been playing about in winisd how does this sound?

av12 with 250w

104L enclosure tuned to 18hz with one 4" flared port which gives port velocity under 35m/sec

Im happy with this but will 250w be ok?

[Collo]

Are you using WinISD or WinISD Pro? The help file in the first one recommends a max speed of 34 m/s. The pro version (still free) has better graphs and has dropped the recommended speed to 17 m/sec.

I'm using the pro version and its database comes with a driver named "Stryke Audio SAE1204". I'm not sure if this is the same driver - if not, maybe you could attach your project file and we can have a play around with it.

On the off chance that the driver is correct, I ran your figures and found:

- Peak velocity is 33m/sec at about 16hz. This falls below 17 m/sec once frequency is above about 23hz. What you are banking on is that there will be be very little full power content below 23hz. This is probably a reasonable assumption.

- Cone excursion fine above 16hz - again reasonable.

- Pipe mode resonance - around 270hz - OK with the low-pass that the PE amps have.

[phillfyspoon]

I have read 34-35m/sec alot of places im using winisd pro.

I would think it is impossible to get under 17m/sec with av12 and 250w no matter what i do it doesnt go anywere near that low, not without insane port lengh

[phillfyspoon]

here is my project file for winisd pro

http://philliphatton.homestead.com/files/av12.wpr

[phillfyspoon]

If i was to use this port

http://www.nexxia.co.uk/Hi-Fi&TVacce...port_tubes.htm

which says 115mm Inner diameter (4.5inch) that would give me 27m/sec at 15hz

and only 33 inches long which isnt much in a bend