Improving the sound of the JBL D123.

I put the D123 in an open back cabinet.It sounds much better than in a ducted port cabinet. No boxy muddy sound. It has the open airy sound of an open baffle system, but with more bass. You still loose some extreme low end, but can always equalize. Also the peaky range of the D123( 1to5khz) is smoother. Harvey Gerst always thought the D123 was one of the best speakers JBL ever made. I wonder if he ever tryed it in an open back cabinet for HiFi use ( not guitar) He said 4 cubic ft was the best for it. I wonder what the best size is for it in an open back cabinet? It goes out to 7 khz where the GREAT JBL 077 takes over = GREAT SOUND!- RUDY

I had these in an GE "Distributed port" design spkr cab that fit in corners really nice. I sold off the drivers yrs ago and still have the cabs in the garage. They are approx 4 cu ft with approx a dozen 1" holes that were for the porting of the cabs. Back in the 50's they were less aware of T/S parameters and had mostly general purpose cabs for most drivers.

Next time I have the time to dig out those cabs I'll take pics of them for possible examples of cabs that DO work well with the D123's! It will be a few weeks as they are buried in the garage.

Ron sends...

Rudy,

Well, you could mount it in the wall and let the back end of the D123 exhaust into another room. That would be best for an infinite baffle. For an open back, or sealed box, the formula is simple:

"Bigger = Better"

Make the box as big as your room dimensions (or your esthetics) allow.

An option for your D123.
Is exactly the option you choose.

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