250Ti - 4-way active experiment

[Dagfinn]

So, while my JBL 250 Ti passive crossovers are in for repair, I thought I might try an active setup - just as an experiment. I have a dbx 234Xs crossover and 4x200w amplification running fully balanced, with 2+2ch gain control, as a test setup. 31-band analog equalizer. Thinking I'll do one speaker first, and keep the second passive, as a model. Have a 12uF cap for the tweeter. I know DSP come to mind for many, but I want to keep it an the analog domain, hoping the dbx will do for the experiment. I have a UMIK-1 and REW, but sonic pleasure is the main goal . Anything else I should think about? Dagfinn

[Robh3606]

Hello

This should help you. The slopes are "wrong" but with the 31 band EQ you should be able to get something usable. Do you have an RTA to use to set the EQ?

This explains the Jubilee crossover but the native driver responses should be similar.

Rob

https://www.audioheritage.org/vbulle...work%20diagram

[Dagfinn]

Thanks, Rob, I'll see if I can decode something. That's quite different from the TI BQ network, btw. Did drivers stay the same for the Jubilee? To be honest, the theoretical side is weak here, so... I have the DAW software wich came with my Motu M4 - it has realtime FFT abilities which I hoped could work. Never used it with the Umik either. I'm guessing there may be better, dedicated softwares out there, is there something you'd recommend? Thanks again. Dagfinn BTW, look at what Greg Timbers has at home .

[Dagfinn]

I haven't used REW before, and I see it has what looks like a nice RTA and signal generator. Never mind the noise here (it's sitting on thwe workstation), but some single tones to each driver on my Genelecs, just to see it works. 400Hz is about on the c.o. border. To late anything more, but looks good .

[Robh3606]

If you have an RTA and a Pink Noise source you have a good start. The only difference in the drivers is the Jubilee uses 050 Gold vs 035Ti. The rest are the same.

Rob

[Dagfinn]

Great, I see the RTA will be very useful. I realize the dbx is limited, but the cost of next level is pretty steep. It seems building a custom active c.o. based on premade modules is possible, but above my skill level. I don't really know a readymade hifi product that fits the bill? Anyway, experimenting for now . Dagfinn.