My 4310WX's back on line, after 22 years' hiatus.

[Doctor_Electron]

After recently reaquiring a pair of 4310's I had sold to a relative in 1986, I hooked them up and did a quick listen.
The sound of the old L-100 vibe was surprising, after being used to listening to my 4410's. They are noticably more efficient and punchier, even after their 36 years of Alnico aging. Not a bad sound, but alas they do not image well compared to the 4410's. (The 4310's ARE currently set up in a nearfield configuration, where their imaging quality should be optimum). They do not sound quite as clean either, though I suspect that is due to crossover issues. One area where they are most impressive is in the bass. Those old 123's really grind out the bottom, and are actually quite close to producing the distinct bass notes indicative of low harmonic distortion, vs. the individual notes being masked by a lot of "flubb".
I think an upgraded crossover would solve all these "problems".
What do you JBL mavens think of this crossover design? Thanks in advance for your valued input, Richard.
URL= http://www.troelsgravesen.dk/JBL_L100.htm#The Kit

[Fred Sanford]

Take a look at this thread while you're at it:

http://www.audioheritage.org/vbulletin/showthread.php?t=13105

je

[Doctor_Electron]

Thanks Fred, this is the kind of info I'm seeking.
BTW, what do you think about the port being sealed?

[Fred Sanford]

Personally, I purchased the plugs and tried them but really only got quick impressions so far, since I'm still moving things around and then recently gutted the L100s for cabinet sanding & oiling.

I liked the sound with the plugs in when I had the L100s up on shelves near the ceiling, seemed to tame some of the boom I was getting from the corner location. Easy & cheap enough just to try them, mine needed a little bit of trimming on the rubber expanding part to smoothly fit the port tubes.

I haven't touched the crossovers in mine yet, but I'd like to do something for a low pass for the woofers at least. I've got a silly amount of amplifiers, I may even actively bi-amp them some day just for kicks.

je

[Doctor_Electron]

I have read and saved the above mentioned thread, and agree in principle to most of its points. That was an excellent discussion overall, but has anyone actually experimented with such more advanced crossovers?
I do essentially disagree with the premise that the older monitors (with their excellent compliment of drivers, top-drawer cabinet construction, and the obvious potential for positive sonic improvement) should be left as is, since such dividing network mods can be effected externally to the cabinet, without permanently altering any physical attributes of the original design & build.
It seems a shame to hold back these systems' performance because of the technology, signal limitations, and applications philosophy/intent of "The Day", e.g. the early 1970's. Also, the demands of today's media are more severe, IMO, than the signal from, say, a common CD player, which I believe to be more difficult to reproduce cleanly than the analog signals produced by the "softer" vinyl, open-reel tape, and [then listenable] FM broadcast media of "The Day".
Anyhow, I want to play with better Xovers, in pursuit of another audio "quest", the sonic improvement of my "old friends", those venerable old monitors.

[Fred Sanford]

One answer you'll get is that JBL themselves continued to improve these models, and simply purchasing one of them (I don't know the specific model #s off-hand) is the cheaper/easier way to the results you're looking for. If you're into this for the fun & learning, that thread I linked to seems to be a very good starting point for crossover upgrades. I got my L100s very cheap (one pair ~$75, one pair free) so it's not a real big deal to me to put some $ into the crossovers- but then again, I don't really love the tweeters so how much am I going to care in the end? For me personally, I think one set will stay stock ('cause it is in every way) and one mongrel set (Century cabs with 4312 components) will probably be actively biamped. I like my L110s and 4333As more, so these will always kind of be backups or just for fun. Your desires and priorities will obviously be different.

je