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Could DRPA help make one type of speaker sound like another?

gabrielsterngabrielstern Posts: 3
Hello dbx users group,
I'm wondering if a DRPA could help me with the following problem:
I am desperately trying to make a pair of JBL PRX712 cabs (powered 12" with compression driver for high mids and highs) sound more like my wonderful sounding but too heavy (108 lbs apiece) JBL 4628b Cabaret speakers (15" and 8" cone drivers and the famed baby cheeks compression driver for the highs).
I use the tops over a JBLPRX718 XLF sub which is very nice indeed. No problem there.
I've A-B'd the tops over and over again, trying to equalize with the eq8 in Ableton (I know, I know...totally inadequate for the job, but it's all I have), and every time I come away with the same evaluation... the PRX712 don't have the same crispness in the highs, lack clarity and definition in the mids, and lack punch also in the mids. It's not an overwhelming difference, but enough to have made me unpopular at Guitar Center, where I've bought different "tops" like the PRX712's and after auditioning them for a few days, bring them back in order to try something else.

I thought equalization might be the tool that could make the speakers sound more alike, but it's just not working. Could the auto eq function in the DRPA be used something like this?:
- Play white noise through a 4628b speaker. This would become the "standard" for the sound I want, with no adjustment made by the DRPA.
- Now play the white noise through a PRX712.
The DRPA "thinking" it's still the 4628b, but in a different acoustic environment (right?), would then auto equalize the PRX712 so that it sounds the same as when the sound was played through the 4628b.
In theory...sounds simple. But would it work?
Thanks,
Gabriel

Comments

  • DraDra Posts: 3,777
    Good question. In theory that would work. Though it is going to be difficult to get a 12 to sound like a 15 in the lower ranges, and a 15 to sound like a 12 in the upper mids. The biggest problem is going to be getting a 12 cone and a compression horn to sound like a 8 cone. Flat is flat and the curves may match, but the dispersion is going to be a problem, in my opinion.

    DRA
  • Thanks for the response, DRA.
    Good point about 12's vs 15's, and I guess it gets more complicated since I'm using a sub to cover the lows (90hz crossover frequency, I think).
    I don't understand why I'm experiencing this "blurred" sound in the mids, and the lack of sizzle. All that I have read says that compression drivers respond more quickly and create a more accurate sound. Vocals, especially, lose some character on the PRX712s and when listening to jazz (A Love Supreme - Coltrane) the snare booms a bit...loses punch, cymbals become duller... in general, it's harder to hear each instrument distinctly.
    I wonder if anyone else on this forum has experienced the same thing on their PA system. I suppose I'm a dreamer and am asking a PA to sound like studio monitors, but the JBL 4628b Cabaret speakers really do come close. I don't mind lugging around the sub. but another 216 lbs for the tops is a joy killer.
    Gabriel
  • DraDra Posts: 3,777
    You should ask this question at the PSW forum.
    http://forums.prosoundweb.com/index.php
    Post in the "Lab Lounge".

    DRA
  • DennisDennis Posts: 801
    Thanks for the response, DRA.
    Good point about 12's vs 15's, and I guess it gets more complicated since I'm using a sub to cover the lows (90hz crossover frequency, I think).

    The closest you will get matching the sound of your speakers would be to manually tune your newer speakers using a dual FFT audio analysis program. It's a steep learning curve and you might want to hire someone to do it. You still won't nail it on the head for the reasons DRA listed.
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