Please help with my first OB

[david yost]

Hello, everyone

I have been bitten by the OB bug, and would appreciate any advice you have to offer.

Directivity control is the primary reason I would like to do this, as I want to build an Ambiophonic rig that relies on crosstalk-cancellation and therefore would benefit considerably from minimal room interaction.

To this end, I have bought several Altec MR64A CD horns which have very sharp H and V patterns as seen here: http://www.altecpro.com/pdfs/vintage...0HF%20Horn.pdf

For bass duty, I have a supply of various Altec 15" and 12" mid/woofers, as well as 4 JBL 2226 units that I can use in any combination to give me the pattern control I am after: which is either dipole or cardioid to mate-up with the horns at approx. 800Hz. My rectangular room is fairly small at 13' X 15' X 8'.

I have a bunch or amps and a Behringer DSP crossover/eq available.

Please give me the benefit of your experience with this project.

Thanks in advance,
David

[DougL]

All I can say is try something.

For OB base, cone area is king. You are looking for high Qts, low distortion and high Sd. If Qts is low, it just means more eq.
Many variations are possible.

I did find I needed to measure to get the Eq right.
However, it was fun to dial in by ear.

Good luck.

Doug

[david yost]

Thanks for the encouragement, Doug.

I did stumble on an Altec cardioid box that may do the job. It is a new one on me, called the 814A, and supposedly has good patern control from 100 to 1500 Hz, which is the range I am concerned with. I have located two of these and they should get to me in the next week or so. I plan to load them with 515Bs which are my favorite mid/woofs.

Here is a link to some more info: 814