Jump to content

JBL L-300s


Recommended Posts

Here's a review I wrote of a friend's JBL L-300s. They're the first JBLs I've really liked.

http://www.epinions.com/review/JBL_L_300_epi/content_570351259268

Can other JBLs (eg L-100s, 4311Bs) sound close to this good? I always find them to be punchy but unrealistic sounding, with no real soundstage and aggressive highs. Would tubes make a difference?

Link to comment
Share on other sites

  • 11 months later...

Hi Colin - just happened across this post and found it interesting as I am a fan of vintage JBL speakers primarily due to their incredible attention to detail in the manufacturing process. You just do not see the quality today for most drivers that JBL put into their mainstream drivers for the L-series models back in the late 60s and early 70s. Never had a chance to hear the L-300s except at a commercial stereo delaer when I was in college but they were the cream of the crop compared to most of the other brands in those days. One speaker that I do have some history with is the L-100 (close cousin to the 4310and 4311) which I purchased for my older brother (for whatever reason, I was considered the stereo expert in my family and amongst my freinds) along with a Pioneer PL-61 turntable and Pioneer SA-9100 amp. This was a quality system back in 1974 but to be perfectly honest, I never warmed up to the L-100s although they were dynamic as all get out. Several years later (around 1989), Speaker Builder was demonstrating a new computer-aided crossover design (CACD)program and they just happened to pick the L-100 for their test subject. If you look at the response graph of the stock L-100, you can see a very pronounced peak in the 4000 - 7000 hz range and this is audible as a pronounced coloration that does indeed give the speaker a definite "presence" along with the punch due to the bass reflex design. I guess this is what they refer to as the "JBL West Coast Sound". The CACD program modifies the simplistic but less than optimum crossover of the stock L-100 (which only has 2 capacitors and a couple of L pads to roll off and adjust the level of the 5 inch midrange and 1.4 inch tweeter at 1500 and 6000 hz, respectively). Since my brother still had his L-100 speakers, I modified them with the CACD program and eventually ended up with -6db points of 600 and 4000 hz for the revised crossover. Parts count increased from the original 2 caps to 11 total ( 5 caps, 4 inductors, 2 resistors). The speakers were now much more natural sounding with good bass but much more natural and smoother sounding mids and highs. While I could never live with the stock L-100 speakers, I really enjoy the modified speakers ( I still have them as eventually all the stereo equipment I got for family and friends ends up back with me). Since the CACD modification is so extensive, it is really changing the L-100 to a new speaker but it improves upon the strengths of the 123A 12 inch bass, LE5-2 5 inch mid and the LE26 tweeter.(In my mod,I replaced the stock LE26 tweeter with a Focal T120K tweeter just due to personal preference). As I said earlier, those vintage JBL drivers are so well built, it seems a shame not to use them to their full potential. There is also a commercially available Jantzen Audio upgrade that does much the same thing as CACD (crossover mod) but it is more elaborate and rebuilds (and loads) the cabinets as well. It seems that the 123A is not really designed for a bass reflex cabinet ( due to its high Qt) and the Jantzen upgrade addresses this aspect as well as the modified crossover. The bass driver really needs a larger cabinet and is better suited to an aperiodic loading.

So there is a better speaker in all those L-100, 4310, and 4311 speakers out there just waiting to be released.

Dean

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...