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Just scored a pretty clean B380. The previous owner has a BX63 he will sell me for $400 but I need to wait a few months to get it. Other than collectibility and originality, is there a better, less expensive way to go? I see the newer Ashly XR1001's have a summed mono sub output I can send to my Crown PS-400 which I plan to run bridged at 680 watts. I can get that for less than half of the BX63. It's also not the A model. What would you guys do?
I waited YEARS to buy a BX-63A ... and finally got one well under that $400 price -Quote:
Originally Posted by 58crewchief
and that price sounds like gouge city! They are 1970 tech and better things are available these days, unless you are going for collectable value ... There is even someone on ebay selling DIY BX-63A kits
I used an Ashly crossover for ages when I ran a biamped pair of JBL studio monitors ...
I'm currently playing around with a behringer DCX 2496 UltraDrive pro for biAmp use -
you can get them used for a bit under $200
They have some extra features that can be handy -
The BX63A sounded very good to me. This could be due to the passive only crossover components in the HF circuit. There was no detectable noise.
On a budget, I would use a mini dsp to replicate the LF bump filter, and crossover point parameters. This would be split to a replica of the passive components from the tech sheet schematic for the HF.
I think SUMO made an all active crossover that can function as a BX63A.
One of the big JBL flippers on ebay was selling DIY aftermarket kits, but I think they were just as much or more $$$
I rescued and rebuilt a B460 and used a cheap 5235 with changes made to mimic the BX63, the info is around here somewhere still...
Guido used a reckhorn B1 in one of his setup, and I did the same.
It does the trick and works pretty well.
Has anyone tried the DIY BX63A? It's a good value it seems. Finding a unit that has the correct 12db slope is tough. The Sumo unit does but is almost as rare as the BX. A Bryston 10b will work but damn, I paid less for a 7B monoblock.
After having an 18 inch JBL 2245 and an 8 cubic foot enclosure I built for it in the 1980's, I finally am trying to set it up with my home built cabinet L-300's to mock up the 460 sub. Having given up on getting a bx63 crossover and the comments I have read about better alternatives, I bought a Crown XTi series 1002 amp with DSP. It is bridged by the new Crown amp and I can set slopes for the high and low pass (so far I am using 20 cps and 63 cps for a band-pass for the 2245. I can also set parametric boost and cut frequencies including frequency, magnitude and Q. It is capable of 1KW of power and has peak limiting with controllable attack and decay available in the DSP.
The enclosure is tuned a little low (about 25 cps, not 27). I could try to cut the 6 inch port a little shorter but a real pain to do it being 40 gage pvc tubing using an extension (even thicker!) on the inside rear of the initial tube.
For a starting point, I gave it a 9 dB boost at 27 cps with a bandpass crossover from -48dB cutoff at 20 cps and a 24 dB/octave cutoff at 63 cps, and a -3dB limit for the max amp output. (about 500 watts peak).
The L-300s are also used as rear surrounds in my home theater setup. They are on the amplifier rear outpout of the AVR receiver normally. This amp feeds the l-300s directly and not the 460 sub.
I may or may not be able to blend the JBL 18 with the front sealed box subs. To try that I would have to feed the rear speaker amplifier as "large speakers" directly using a line level on the rear channels from the AVR. It would have enter the rear preamplifier as an auxillary source with a second volume level (one on avr rear channel and the second on the preamplifier driving the l-300 amp and the 460 amp) or I would have to substitute the feed for the output of the rear preamplifier to drive the two rear amps that way. I could also try feeding the "460" with a y output from the front sub input line. I have home built 4343's for the front and a pair of SVS 16 ultra subs for the theater. Sides are using a 4 cubic ft cabinet with LE85 compression drivers on JBL and 2206 12 inch drivers and a Beyma FD 212 passive crossover. I finally got all 6 ground level surrounds on JBL le 85 compression drivers and woofers!
Any suggestions on the crossover, eq and the limiting etc? I do have a couple of room response programs (like true rta) I could try but am never sure how well they really work in the - 30 cps realm. Am I in the right ballpark with my settings? any suggested tweaks?