Best DIY project with pair of jbl 124a

Hi all,

I have a pair of JBL 124a in good condition and been trying to determine what would be best 3/4-way DIY setup I should be looking into. I was tempted by 4315, but I can’t find the midlow woofers available anywhere. Not much diy documentation on them either.

I like big open sound (ie horn based).

The Jbl L65 jubal. Not sure about this. Is the 5” driver a good match with the 12” woofer? I like a rich warm presentation.

I read on a thread that the 124a/h are great just as a subwoofer. It is an option but I feel it is a bit of a ‘waste’.

Happy to hear your thoughts.

Cheers!

Get a pair of Heil drivers and try a 2 way. I use Heils with 121A's subwoofer variant of the 124's. Sounds good running active with a simple notch filter. Or you might be able to use 2118h's for the 2108's but it will take a bit of work to pull it off.

Rob:)

I have a pair of B&G RD50 planar drivers that may pair well with the 124a woofers. Didn’t even think of that. What would be optimal cabinet design/size for it though?

I love JBL 4 way studio monitor designs, but seeing how complicated their passive networks are for them to work correctly makes me realise making a custom design (ie mix of different drivers and cabinet from original) puts me off.

I’d like to try go passive with whatever I go with. It seems 2 or more likely 3-way would be good for the 124a.

I’ll keep researching :)

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What would be optimal cabinet design/size for it though?

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I would use the same box volume as the 4315 and just build a removable top baffle like the 4343 and keep looking for drivers. That way if you find them you can just change the baffle for the new driver set or try other combinations if you want. If your planar driver is a dipole like the Heil just invert it woofer on top so you can get the driver close like my avatar which are 2 separate boxes.

Rob:)