2 d123,s in same cabinet

[rudy sesztak]

I have a 5 cubic ft. cabinet. My jbl chart says 26sq in port, no duct,for one d123. Can i use 2 d123's in the cabinet with the same port? What would be the f3 with 2 d123's vs 1 d123 in the same cabinet? Thanks for any help on this.-RUDY.

[spkrman57]

I used to live in that zip code many years ago.

If you drive 2 drivers in a cabinet designed for just a single driver, you will have a "mis-aligned" system that will not operate flat across the bandwidth.

On the other hand, I have had D123's and they don't have that much bottom end response. But they are efficient and if supplemented with a powered sub below can be very satisfying.

If you ever travel down/through Columbus, you should contact me for a visit and we can discuss your system.

You are 2.5 hrs away drive time.

BTW - What is your total system design goal, and are you running tubes or SS?

Regards, Ron

[tomt]

.

On the other hand, I have had D123's and they don't have that much bottom end response.

Regards, Ron

Actually, they do.

A friend put a pair of d123,

in each cabinet,

12 cubic feet,

and feed them with a Crown DC-300 .


http://www.youtube.com/watch?v=17toENAJqvk

They go quite low.

[RMC]

Hi Rudy,

Very quick modeling of D123 using only the three minimum parameters required to model LF response. No time now to do a complete modeling with vent data using all TS, would need to add these in Winspeakerz software.

Still gives an idea of what to expect in terms of bass. As usual i try to model with relatively flat LF response, QL 7 and half space loading.

1rst pic one D123, 5 cf box, top curve Fb 45hz, lower curve Fb 40hz

2nd pic two D123, 5 cf box, top curve Fb 45hz, middle curve Fb 40hz, lower curve Fb 35hz

Two woofers = more output but not deeper bass, in fact one woofer has lower F3. The choice between one or two woofers in that box is pretty obvious in my view.

With pretty old drivers one has to be careful bass wise regarding limited driver excursion capability (2.54 mm) vs output level... Regards,

Richard

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