It was Greg's active solution suggestion for the 4344/4345.
Basically any decent 12 dB/octave or 24 dB/octave LR filter wherein the voltage drive is 6 dB down at the target crossover frequency of 200 Hz to 400 Hz. I believe his specific combination of capacitor/resistor values resulted in a crossover frequency of 310 Hz. Or maybe that was Rod's. Whatever works in a specific room in the 200 Hz to 400 Hz range.
I didn't want to get into another argument about specific brands. And if some folks want to trick out older electronics it could be fun.
2ch: WiiM Pro; Topping E30 II DAC; Oppo, Acurus RL-11, Acurus A200, JBL Dynamics Project - Offline: L212-TwinStack, VonSchweikert VR-4
7: TIVO, Oppo BDP103D, B&K, 2pr UREI 809A, TF600, JBL B460
Just found this thread, I've been owner of 4345 for 2 yrs, bought from another forum member from a S.Carolina recording studio. The experience with the 4345 are both rewarding and hard on the money, you need a deep pocket to bring out the best of these sensitive studio monitors. Here is a list of what I use:
Pre: ARC SP11 MKII
Crossover: Bryston 10B Standard, RCA, set at 300HZ
for high,140 HZ for low, both on 12db slope.
Power: Top: Canary 303 (18W, 300B PP)
Bottom: Bryston 4B ST
Source: Digital: Pioneer universal DVD player DV989
Analogue : Micro Seiki BL91/ FR64FX/ EMT JSD5G
Accessory: PS Audio PS1000 power conditioner
The 4345 is quiet sensitive to what you use in the system, every cable change, component swap,would bring a profound effect to the sound, not to mention playing with crossover frenquency or slopes.
If there's complain about 4345 will be the 2405, mine unit barely wispers, but set it at plus 2, it brings correct sound image. For the moment I am keeping it stock, modification to the crossover is tempting. On the Bryston 10B, since it doesn't have a 290 HZ setting, I don't know how it has impact the sound by setting the highs on 300HZ. If it's somthing I can live with, it will be a project for the future.
All,
I am still in the process of finishing my JBL4345 clones. Just wanting for network/crossovers to be finalized.
Once the speakers are done, I was planning on bi-amping them. I have been given the opportunity to purchase a McIntosh MC7270 for a very fair price. It is 270wpc. I wanted to know whether you guys think it would work well for my intended purpose (i.e. simply running the 2245Hs in my JBL 4345s).
Thanks,
D
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
I have a Nelson Pass'ish DIY amp driving mye 2245's. It is ~160W/8Ohm.
I find it sufficient when I want to crank up the volume, and simply wonderful at any volume.
Johnny Haugen Sørgård
Me too. It never stops...
Current config has:
The Widget stopped by the other day, and we both (re)marvelled at how good this simple 2.0 system sounds. The tonality thru the 2245's is a real marvel; the highs through the TAD TD-2002's is matchless; transients real.
- Bryston 10B, Linkwitz-Riley -24dB slope
- 2245's are being driven by a QSC CX502 (300 w/ch 8 Ω)
- Upper band passes are driven passive by a Lab Gruppen fP3400 (1000 w/ch 8 Ω). I know, it's about 5x what I need, but is the only spare LG I had sitting around, I love the way they sound and I set the MLS switch to -5dB = 300 w/ch 8 Ω).
I probably should go Class A on the upper band passes. Maybe some day...
I agree with you and Widget, the TAD's transformed mine too. Hey Bo, before you jump to class A, about a year or so ago, I put a Bryston 2BSST(squared) on the top of mine and had very positive results. So much so, I decommissioned my DIY fully balanced high end tube stuff, pronto. I use a 4B SST2 on the bottom.
To add icing on the cake, I recently added a second 2B and now run them as balanced monoblocks for even better performance. No need for the extra power, of course, but the advantages of running fully balanced differential config. works very nicely.
Well vintage amps don't look much better than a 7270. BMW guy loves his 160ish WPC Crown, I have a 350WPC Crown, someone said their 60 watt tuber sounded best. Then again my best bud in Texas runs a 7270 through his 45's by itself and loves it [has had a sheltered life]. Personally, I would love to have the 7270 to match my 2125 [top] and Mc preamp just for the looks. Rumor has it that there are more modern reliable amps that would work better, at a lesser cost. Yes it will work. Buying public is nuts over old McIntosh, so if it doesn't work for you, sell it and move up!
I'm certainly not suggesting the Crowns as the ultimate here. There are several other amps I'd love to try. I suggest the Crown PS and D-series amps as low-budget alternatives. (I'm paying for private college educations for three daughters, and non-renewal of my employment contract last year put a crimp in that, keeping me a "bottom-feeder" for some time yet.)
The latest PS-400 cost me $100 in perfect condition from a studio in a Maryland suburb of DC off Ebay. The PS-200 was only a bit more but came in Crown packaging direct from a recent factory performance check and service with all the receipts from Crown showing twice what I paid for it as the invoice cost of the check-up and service.
Good advice above, though. Macs are always easily re-sold if bought in a reasonable range. Certainly easy enough to try it and decide. I still keep my C20 around for fun since we've been together for over forty-years now.
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
Yeah, too bad JBL couldn't make a nice 1" exit compression driver. Oh well. I'm using grungy old Citation 22's on the top and bottom and they sound just fine (And I've heard some seriously expensive gear over the years.) My next choice would be the Brystons mentioned above.
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