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I’m building a vintage vinyl based system for my son’s college graduation gift. The Rek O Kut L34 CLD project turntable is underway and the Marantz 2230 is ready to go. I’m looking for some insights to make sure we’re headed down the right path for speakers. My sister offered a beautiful pair of JBL 4311Bs from her bedroom system she “wanted to get rid of”. Before I invest a lot of time preparing the speakers with a looming deadline, I’d like some sage insights on;
a) 4311B compatibility with the 2230 (if needed, I could always give him a Scott 370R or keep looking for speakers),
b) advice on set-up or stands (the tweeters are at the bottom), and
c) what potential issues or quirks should I look in to (e.g. crossover capacitors, tweeter foam rings, woofer surrounds, and all those 4311B pots).
Follow Ups:
I spend a fair amount of my life lurking in the asylum (sounds twisted doesn't it) and I can't get over the collective knowledge in the forums. Equally impressive is the depth of experience (that includes you Jerry), the willingness to help, and the unexpected humor. This project should turn out great, my son will love it! (Vintage, Vinyl, Tweaking and Tubes - looks my kids are turning over to the dark side.)
Check out the link provided by Steve O in this thread, also my response.
Nice speakers, the later version of the 4310 that was the basis for the consumer L100. Later L-100's (the L100A) used the side by side mid and tweeter like your 4311B's.A couple of points. Those are L-pads, not pots, and if the speaker has not been abused, should be OK. Crossovers were very basic in that series and is probably not much more than a couple of capacitors.
The speaker is a professional model designed for control room monitoring and designed to be wall mounted (or set on top of the console) with the mid and tweeter at ear level. There is no reason they have to be used with the tweeters on the bottom, so flip them over and keep the tweeters on top. They work very well on 12" to 15" stands with the tweeters on top.
The 2230 ought to match pretty well. A good friend used his L-100's for years with a 2230 and we all thought it sounded great. He later replaced the 2230 with a Yamaha R9 and I thought it was a step backward.
The response curve is fairly bumpy, which gives the speaker a lot of it's punchy character. Dennis Murphy has done a crossover redesign that fixes most of that. You can find it at his web site murphyblaster.com He's a very talented crossover designer, which he does as a hobby. He's actually a PhD economist for the FTC and he plays the violin in an orchestra. The crossover design is for the side by side layout in the 4311B, but do check the driver complement as the woofers may be different in the version he worked on. The JBL web site has the owner's manuals for the consumer and pro models and they typically do list the driver model numbers. I visited the 4311B manual and they are listed. I'm pretty sure the mid and tweeter are the same in the one he worked on (L100A) and the 4311B.
Woofer surrounds won't need replacement, they are corrugated fabric. The tweeter rings might if they were foam. The L-pads are necessary, and should need no more than some Caig De-Oxit 5 squirted in. The crossover caps were high quality, but about 30 years old. if you don't go with the Murphy mods, I'd replace them with new caps of a similar type.
Note: I would not recommend "upgrading" the caps. The speakers are bright enough as is. If the original caps are non-polar electrolytic, then replace them with non-polar electrolytics. The most I would do is to parallel the NP electrolytics with a very small film cap and adjust the values to get the same nominal total as the original. JBL did this in their later 4400 series monitors.
My bad!I just checked Dennis murphy's web site and the L-100 mods are not there. He had posted them on the Madisound forum (the Mad Board) and I assumed it was on his web site. Sorry!
He's a nice guy, so if you e mail him I'm sure he can send you the details.
The attached schematic is from a discussion on HTguide ~9-06 and is apparently the result of Dennis Murphy's work to improve the L100A.I don't care for the shunt cap on the HP portion of the circuit from a theoretical viewpoint but a model of this indicates no nasty impedance issues till well above 20KHz. Maybe it's OK in real life.
Yes, that's it. Thanks. Happily, the schematic also includes the driver model #, which are different than the 4311B as I had thought.L-100A: woofer 123A, midrange LE5-2, tweeter LE25
4311B: woofer 2213H, midrange LE5-10, tweeter LE25-2As it turns out, the woofers have identical parameters both electrical and mechanical, despite looking different. I'm not sure about the mids and tweeters, but a lot of the differences between models is in mounting, finish, and cosmetics; so I'd be inclined to give it a chance.
This would be a classic matchup from YOUR college days (70's?). This is close to the system my roommates and I had in 74. Marantz 2215,I think, and L100's. Plaster cracking loud and sounded great at lower levels too. 4311's can be turned anyway you like. Tweeters should be at ear level where on stands or bookshelf. There are a number of 'upgrade' options outlined here and other forums such as audioheritage.org. Look for references to l-100 these are close to the same thing.
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