| If you willing to dedicate one Goto 146 for upper
bass and one for midbass then it sound like a good idea. Let presume that you
have 400Hz-600Hz MF driver as your base and the rest consecutive channels above.
I am sure that you will eventually get rid of your JBL MF and go for a vintage
solution but it will be later and to give 400Hz-600Hz as the bottom knee for
your prospective MF sound like a reasonable idea. Now, calculate the space you
would like to have for your upper bass driver. You need to know juts 2 parameters:
exit of your upper bass driver and desirable sixe of mouth. Let juts for a sake
of illustration you figure out that you can put 1x1M horn. That would allow you
the MF to be at more or less reasonable elevation. The mouth would make let say
100Hz horn rate and if you go with fast opening profile then it will be 1.2M
long. This will be time-alignable combination. Also, if you won’t be able to
rife the Goto146’s Fs all the way up then you end up with 4” entrance horn and there
are plenty of other drivers that you will be able to use. Now it is the time to
model how you implement the upper bass horn. Be advised that if you go for 40H
then you do not want this horn to shoot toward to you. Most likely it would be
curved horn, so use your imagination how to incorporate it in your room. No one
could do it buy you. If it as up to me then I would start from Upperbass horn
and MF, then after I make the Upperbass and FM tandem to work properly in my
room I would supplement it with a direct radiator bass channel and work on
perfection of the upper horns. In my mind, looking at the questions you ask you
are not ready to undertake the midbass project. You might return to it in a few
month after you get a success with your upperbass horn. |
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