JBL's compression drivers

[dznutz]

So, what are people's opinion on JBL's compression drivers and their implementation?

I have auditioned the Array 1400 and the S4700, I can only describe the sound as big and "real"

[dznutz]

Hmmm, no opinions huh

[jpw]

I agree with you. They have what I call a very "alive" sound. Others might call it dynamic or uncompressed.

I find this quality more important for the simple reason that aliveness is what convinces me that there might be live music happening in my room, rather than a reproduction of such. To appreciate this fact, just stand in the middle of a group of musicians that are playing, like you are a band member.

Small movements of diaphragms for a given SPL allow for both lower distortion
and a quicker response time getting from the neutral starting point of the diaphragm to the maximum voltage point represented by the waveform. So larger displacement cones, at bass and lower midrange frequencies, have a benefit over small cones, up to a point. In the treble, physically large tweeters have too many problems, so horn loading can solve the problem by reducing diaphragm motion considerably.

Even though these larger woofer cones or compression diaphragms are heavier than small moving coil drivers consider this analogy. A 200lb man that only has to run a 10 yard sprint (back and forth), will have a time that beats a 100lb man that has to run 40 yards. An unfair comparison with distance? Consider that the widely used 6.5" woofer has one fourth the cone area of a 15" woofer and therefore has to move in and out four times further for the same SPL. With this extra motion, guess what happens to distortion.

[dznutz]

I agree, its also quite puzzling as to why JBL is the only company manufacturing speakers with 15" bass and compression drivers... extremely advanced ones too. The only other company which I know of is Magico... in their "Ultimate" speaker which retails for around $600K!!! If Magico feels that compression drivers are needed for the "ultimate" speaker then does that mean that JBL's offerings are a bargain?

[Dave_72]

Originally Posted by dznutz

I agree, its also quite puzzling as to why JBL is the only company manufacturing speakers with 15" bass and compression drivers... extremely advanced ones too. The only other company which I know of is Magico... in their "Ultimate" speaker which retails for around $600K!!! If Magico feels that compression drivers are needed for the "ultimate" speaker then does that mean that JBL's offerings are a bargain?

A bargain? In comparison, absolutely. Keep in mind that the high end JBLs are mass (or semi massed) produced and probably sell more than Magico.

[Dave_72]

Originally Posted by dznutz

So, what are people's opinion on JBL's compression drivers and their implementation?

I have auditioned the Array 1400 and the S4700, I can only describe the sound as big and "real"

My opinion is this: It's a very dynamic and lively sound. It's not for everyone, but I like it, and that's all that matters to me. I have found that the S4700s that I use can also take whatever you can throw at them, no problem. They're both rugged and refined. JBL really did their homework on the Synthesis line, I'd say. Hook 'em up to the proper electronics, and they'll be very rewarding. However, I have found with the S4700s, that a lot of break-in time is needed. Probably at least 300 hours.

[jpw]

I think at least three things are responsible for the lack of US market presence for home horn loaded speaker systems. In contrast, JBL sells lots of them in Japan.

#1. With the advent of high powered and relatively cheap solid state amplification, high efficiency horn loaded speakers, which also cost more to build and were physically larger, gradually lost popularity to low sensitivity speakers which were smaller and cheaper to build. With sagging sales, no money was available for R&D or marketing, so high efficiency designs atrophied.

#2. Another factor is horn loaded speakers have a huge image problem born from real experience. Most people's exposure to them comes from the often unpleasant sound they hear over PA systems. They haven't heard the "good" horn speakers like JBL's more recent efforts, only the bad.

#3. Most of the audio press in the US either ignored them, or if they actually reviewed them, had thinly veiled contempt for them. Unfortunately, in many cases their scorn was justified.

This has led to a prejudice against all horn loaded speakers by most audiophiles that has only slightly diminished with time.

It took decades for polyester to overcome it's bad rap from the leisure suits of the 70's.

Given that there is no prejudice like an audiophile prejudice, expect it to take much longer for horns.

Only more recently has technology improved sound to the point where several high end companies have come back to market with horn loaded designs. Perhaps companies like Magico will open audiophiles ears and lend respectability to horn speakers sooner than I think, but I'm not holding my breath.

[Dave_72]

Originally Posted by jpw

I think at least three things are responsible for the lack of US market presence for home horn loaded speaker systems. In contrast, JBL sells lots of them in Japan.

#1. With the advent of high powered and relatively cheap solid state amplification, high efficiency horn loaded speakers, which also cost more to build and were physically larger, gradually lost popularity to low sensitivity speakers which were smaller and cheaper to build. With sagging sales, no money was available for R&D or marketing, so high efficiency designs atrophied.

#2. Another factor is horn loaded speakers have a huge image problem born from real experience. Most people's exposure to them comes from the often unpleasant sound they hear over PA systems. They haven't heard the "good" horn speakers like JBL's more recent efforts, only the bad.

#3. Most of the audio press in the US either ignored them, or if they actually reviewed them, had thinly veiled contempt for them. Unfortunately, in many cases their scorn was justified.

This has led to a prejudice against all horn loaded speakers by most audiophiles that has only slightly diminished with time.

It took decades for polyester to overcome it's bad rap from the leisure suits of the 70's.

Given that there is no prejudice like an audiophile prejudice, expect it to take much longer for horns.

Only more recently has technology improved sound to the point where several high end companies have come back to market with horn loaded designs. Perhaps companies like Magico will open audiophiles ears and lend respectability to horn speakers sooner than I think, but I'm not holding my breath.

I agree. But JBLs high end horns are getting pretty good praise here in the US if you look and dig around. As far as sales go, I'm not sure on that. But, if they were hurting, you better believe Harman would get rid of them. The horn JBL Synthesis speakers do not honk, squawk, or whistle at you. They are in a league of their own, imo. They're certainly not cheap, and perhaps overpriced, but compared to the smaller companies considered the big high end players, they're very much competitive and are actually cheaper. They can be had at a much cheaper price than retail at most Synthesis dealers. I paid just a little over half off on the S4700s.

[lynkage]

Originally Posted by dznutz

So, what are people's opinion on JBL's compression drivers and their implementation?

I have auditioned the Array 1400 and the S4700, I can only describe the sound as big and "real"

I just love them!! They are quite amazing in my book. I have a 1400 array like system and by that I mean the vertical horn but I have the 476Mg bolted to it. Just amazing!!

[TWiiii]

I don't think its the driver that determines the sound we hear as an individual part. . The horn that couples the driver to room and the choice of crossover parameters also influences the sound. The choice of tweeter if there is one can make or break the sound of a midrange horn. And a lot of the sound contributed to a horn is actually shared or is mostly the upper ranges of the woofer. And if that sound isn't correct the whole production chain of sound is a failure. And though the diaphragm is a part of the driver, different diaphragms with the same driver makes it an entirely new reproducer. If making diaphragms were easy; then, why do nock off diaphragms never sound right?