[guest42212]

Since an open baffle rolls off the low frequencies @ 6db / octave below a frequency determined by it's width, shouldn't a BSC circuit flatten the response in the same way it is used with box speakers? (if set for 6db compensation) See link:
http://www.quarter-wave.com/General/BSC_Sizing.pdf

[JohninCR]

A BSC circuit is only going to correct for the first octave isn't it?

I use a 1st order low pass filter to cancel out the dipole rolloff for almost every bass augmenter I use.

[guest42212]

A BSC circuit is only going to correct for the first octave isn't it?

Not if I understand it right (and I'm not sure I do)
It appears that the LP (slope adjustable by the resistor value) starts to rolloff at the point set by the inductor value.
So if you had the network set for 6db/oct at the baffle cutoff frequency you should get the infinite baffle response of the driver?????
I just tried it (not optimum with some xover parts available) and it definitely works but I'm not sure exactly how well.......Need to pursue it some more.
Did you look at the article linked to ?

[guest42212]

http://www.audioasylum.com/forums/hug/messages/119354.html

[JohninCR]

Two words - bass augmentation.  Use a fullranger for wide range sound and you get to keep the magic.  I've found that separate bass augmentation also sounds better than the boxed variations using fullrangers to manipulate more bass, like rear horns and TL's.  Time to give in and accept the inevitable, your fullrangers will thank you and they'll sound better too.

[guest42212]

http://www.audioasylum.com/forums/hug/messages/119363.html

[guest42212]

I use a 1st order low pass filter to cancel out the dipole rolloff for almost every bass augmenter I use.

It seems maybe 2nd order may be more in order
6db to compensate for the baffle, and another 6db to actually roll the 'helper woofer(s)' off ?

[JohninCR]

No, the 1st order is just to flatten response to the baffle cutoff.  Then I just add filtration as an XO wherever needed.  Keep in mind that I go for small baffles, so a 2nd order filter down low rolls the woofers off too early.

[guest42212]

No, the 1st order is just to flatten response to the baffle cutoff.  Then I just add filtration as an XO wherever needed.  Keep in mind that I go for small baffles, so a 2nd order filter down low rolls the woofers off too early.

OK ...... Coil to compensate for baffle rolloff (simulate response in closed box)
Additional xover as needed to mate response to FR (or whatever).....?
How do you calculate the first coil ?

[JohninCR]

No, the 1st order is just to flatten response to the baffle cutoff.  Then I just add filtration as an XO wherever needed.  Keep in mind that I go for small baffles, so a 2nd order filter down low rolls the woofers off too early.

OK ...... Coil to compensate for baffle rolloff (simulate response in closed box)
Additional xover as needed to mate response to FR (or whatever).....?
How do you calculate the first coil ?

I don't.  I use an active PC based XO, so those guesswork days and winding coils are over.  Just point and click to change live, and settle on what sounds best.  Soon I'll be measuring too.  Then it will be a matter of making the graph as flat as I wish in seconds.

[guest42212]

>I use an active PC based XO, so those guesswork days and winding coils are >over.  Just point and click to change live, and settle on what sounds best.  >Soon I'll be measuring too.  Then it will be a matter of making the graph as >flat as I wish in seconds.

Cheater

[JohninCR]

Cheater

If that's cheating, then yes I am.  Much more of a cheat is being able to tell my computer to give me a 5 hour list of blues and classic rock that I haven't listened to in at least 60 days, and that I have rated at 4 out of 5 stars or better.  Then click play.

[guest42212]

needs work but .........................:
http://home.comcast.net/~jhyamamoto/efftest.xls