Okay, I know the theory behind Isobaric, I have seen lots of line drawings of Isobaric woofer setups, "cone to cone", "magnet to magnet" and "cone to magnet", but very few real life build examples, expecially in non-subwoofer applications.
Since I am looking to build a multiway full range speaker and not a subwoofer, the easy "cone to cone" is off the menu and I will instead have to do "magnet to cone".
My question really comes down to the size of the physical chamber between the two woofers and properly "venting" the front woofer.
I don't know how increasing the chamber size between the two woofers to allow for front woofer venting effects coupling between the two woofers.
Does a larger chamber between the woofers decrease the coupling effect due to air compressability?
I would expect the smaller the chamber the better, but the chamber needs to be large enough to allow proper front woofer venting so it can breathe.
Also playing into this, since there is a mid woofer above the pair of isobaric woofers, a larger coupling chamber between the woofers increases the
centre to centre spacing between the woofer and the mid woofer above it.
My guess, and I think what I will go with is, as large a chamber as required to allow for normal rear venting on the front woofer as I would do on any other build, ignore the larger center to center spacing that that forces and deal with it in the crossover. The C-C not being as important as it would be in a two way, because the XO point is going to be in the 100's of Hz and not >1000Hz.
Shots of the 7" woofers in question to show how closed the frame is and various Isobaric configs.
Thoughts on my rambling post?
Since I am looking to build a multiway full range speaker and not a subwoofer, the easy "cone to cone" is off the menu and I will instead have to do "magnet to cone".
My question really comes down to the size of the physical chamber between the two woofers and properly "venting" the front woofer.
I don't know how increasing the chamber size between the two woofers to allow for front woofer venting effects coupling between the two woofers.
Does a larger chamber between the woofers decrease the coupling effect due to air compressability?
I would expect the smaller the chamber the better, but the chamber needs to be large enough to allow proper front woofer venting so it can breathe.
Also playing into this, since there is a mid woofer above the pair of isobaric woofers, a larger coupling chamber between the woofers increases the
centre to centre spacing between the woofer and the mid woofer above it.
My guess, and I think what I will go with is, as large a chamber as required to allow for normal rear venting on the front woofer as I would do on any other build, ignore the larger center to center spacing that that forces and deal with it in the crossover. The C-C not being as important as it would be in a two way, because the XO point is going to be in the 100's of Hz and not >1000Hz.
Shots of the 7" woofers in question to show how closed the frame is and various Isobaric configs.
Thoughts on my rambling post?
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