angle of baffle if any question??

[njkmonty]

i was looking at my jc120 and fender twin last night and noticed a very light angle to which the baffle/speakers where set. Instead of being(the speakers) 90 degrees to the floor, they seem to slightly be angle up. im building a 2x12 g12h30 and cel blue.
should i just have the speakers parallel to the floor or slightly angle them?

[krx]

The angle will let you hear yourself a little better. I think 5 degrees is the tradition. Don't know if it'd be a good idea closed-back though -- you might get some weird internal reflections. I guess they do it on the Marshall slant 4x12s and they seem okay though.

[katopan]

I angled my 1x10 15 degrees. It makes a difference in hearing yourself on stage. But 15 is a lot, especially for bigger speakers (adds to depth of cab).

It's better for closed back too. Having the front and back directly parallel allows standing waves to be generated creating resonant frequencies, and means the reflected wave comes straight back out through the speaker cone. A bit of an angle will help prevent both of those.

[Cknopp]

Has anyone here used the "Waveguide design" function of CATIA to seriously study these things? I have the program, and gave some thought to it, but didn't really know what I would be aiming for.

I remember seeing an old Ampeg Bass cab that had baffles and deflectors for projecting the sound into the room, but never came across any information as to why it was done that way.

Is it realistic to think that you could use a 8inch speaker in a 2x12 cab, and using baffles, still have the same amount of sound coverage?

This may be something that I would be very interested in modelling and doing the wave dynamics analysis on, but would need some more information to know what I was trying to accomplish at the end.

[paulschnettler]

As been mentioned here before, the AX84 site has an 1x12 cabinet design that was developed using dynamic analysis. I'm not sure what program was used but the design is a closed back version with a port located about 1/3 of the height of the back panel. The port opening size is dependent on the type of instrument/tuning you plan on using. (lead/midrange/bass). The testers looked into modulus of elasticity of the wood used and what speakers were likely to be placed. Overall a nice exercize in cabinet design and well worth the read.
I have collected the relevant discussion posts and have in a .pdf file. If you're having a hard time finding tthe info at tghe AX84 site, shoot me a message and I'll be happy to email the packet of info.