Non sub IB v.s. OB

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Comparing IB vs. OB is apples to oranges IMO. I would recommend IB only if your primary concerns are architectural/aesthetic (you don't want to see your speakers) and/or you have very limited space. There are also lots of commercial IB speakers available ready to just purchase and "drop in" to your walls, if you don't want to build. IB applications IMO are an excellent choice for home theater, but not for the best possible musical reproduction.

OB will give you a more realistic simulation of a live performance, if properly executed, but of course require "in-room" placement, a relatively large room, and with commercial designs rare and expensive, will require DIY, which is what you're probably planning to do anyway.

So it boils down to your priorities - what are they?
 
Primarily interested in music reproduction. My ideal system would be all horns and tubes but haven't the funds for that just yet. :)

My current situation is that I have a 70s vintage Sony Receiver driving some butchered JBL 902VX. Several years ago I got the speakers out of storage to find the woofer surround disintegrated. Not knowing that I could replace the surround I pitched the woofs :rolleyes: and slapped in some salvaged 12" organ speakers and stuffed some socks in the ports (figured that mismatched ports would be worse than no ports). Well it works better than it ought to but I noticed that the mids are rotting now. It would be fairly cheap to replace the mids (tweeters are poly so no rot worries there) but this seems like the perfect opportunity to experiment a little.

I have on hand the organ speakers which were used in an open back organ so they are probably OK for IB or OB as far as the Q is concerned. I also have a couple of the rat shack 5" fullrange drivers which look like fostex type as well as a couple of old philco drivers that look like they came from an old console system. I haven't measured them but they look like 6.5-7". I also have an assortment of cone and dome tweeters.

My thought was to use the organ speakers and one set of the full ranges for my main system (with possible tweeter helpers) in either IB or OB with the other fullrange set used as OB in my work room.

The main room is a not too large livingroom (maybe about 14' square. Each side of the fireplace has a recessed area about 1.5 to 2' deep with three shelves. Right now the 902s are on the top shelves and it images pretty well. WAF would be enhanced by IB mounted in those recesses v.s. big OBs out in the middle of the floor. Bass performance should also be better I would guess (don't have a big budget for eq. and such). I would remove shelves as necessary.

Once I got things going with the existing drivers the next step would probably be an IB sub (easier to implement than architectual horn) and then upgrading to tube powered horns for 60Hz and above.

Would the concensus be that the OB - properly placed - would provide better soundstage, but not quite as much bass output, compared to an IB implementation.

mike
 
I disagree that an OB has a better soundstage. I never listened to an IB setting, but I had a clearly improved imaging when I added side walls to my OBs and reduced the dipole character. Dipoles sound like lots of space, but don`t reproduce the room where the recording was done. Fullrange drivers have to be used on axis, even fiveinchers.
 
An IB design in volume but not baffle width above the modal region for the room its in would be preferable so long as you eliminated any obstruction that caused acoustic resistance, you eliminated any reflection to the rear of the driver's diaphram, and you eliminated any pressurization near the driver that could effect it. (note that the reduction in baffle width will have negative consequences in baffle step loss - but that can be corrected with another driver.)

All of this can be done - but it isn't easy (in fact its REALLY difficult and requires a LOT of volume). An OB on the otherhand is easy.
 
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