Oh you are a hard lot to please...you JBL types.
Oh you are a hard lot to please...you JBL types.
I will add "fruity presentation" to the audiophile lexicon here....
########Not nearly much as the non JBL users around here..they know who they are.
Don't they make white wine in CA? #############
"better timing than the PMC"
Timing ?!? What, did the speaker dance like Elaine? Timing? You gotta explain that one.
I really don't understand you post.
You will have to go hear a TL to appreciate the remark.
The bass often by design appears not as responsive as the rest of the system.
I've heard many TLs, going back to IMF and Fried Model H days . And I've heard speakers with good bass, bad bass and no bass but I never heard a speaker with bad timing.
Now I played with a bass player with bad timing, think it was his amp and not him? ;-) Acoustic 360.
I own a pair of the PMC's that Ian mentioned (sounds like he was listening to the OB1 -- http://www.pmcloudspeaker.com/ob1.html).
They are lauded by the hifi press over here in the UK. I just found the bass slow and ponderous, not sure what the correct term is but it just sounded wrong to me. The rest of the spectrum is OK I guess but nothing special really. Also, if you ever extract the OB1's drivers, you may be surprised. There is no real substance to them at all, the woofer and midrange in particular are a real disappointment for a speaker that retails for £2,700 or US$5,000.
From what I remember, the woofer has 1" voicecoil and magnet weight less than 0.5kg. It's similar to this one out of the PMC FB1 (the whole driver is 6.25" remember).
The JBL's wipe the floor with them.
It was a bit of a let down. the blurb suggested they had it worked out.
To Tom, Another defining moment for that Nelson pass Quote.
No offence intended but you first post and of course your last post has me wondering.
For the less appreciate timing errors can be a lot of things.
Its generic statement often used to describe blurring of transients and loss of focus and clarity.
Driver offset, ringing of poorly designed or poor use of drivers, long group delay in bass systems and crossovers can interact witn drivers and calls ringing, phase shifts etc.
The Kantu by design as a simple two way was the least offender in this department. The woofers appear to operate in an over damped manner and the ceramic dome works as a point source in piston mode over most of its range. But it suffers other issues.
Every manufacturer will proudly list 'Frequency' response data for their design but 'Time' reponse data is really never seen. At bass frequencies, the time response is just as important (more important?) than outright extension. It effects all matter of things right down to the way a speaker drives the room modes (a very important trait to consider).
Out of interest, I have seen time reponse data for the venerable Yamaha NS10 and Auratones. When compared to other competing products at the time, it actually explains a lot about why these were favoured by many top rock/pop mixing engineers for their "punchy" sound. Within their design limits, their time reponse is very "tight" even though absolute extension isn't great. You always have to trust you ears and that is exactly what these experienced mixers were doing.
"No offence intended but you first post and of course your last post has me wondering."
Indeed. I'm aware of speakers with lousy bass and what makes for lousy bass but I've never interpreted bad bass as bad timing, just bad sound. I can tell timing with good bass, bad bass or no bass. I remember listening to WLS-AM over a transistor radio ear-piece 45 years ago and having no trouble with the beat.
could it be that some transmission line designs have a slight but perceptible lag time?
I think so, its a characteristic of that type of design.
There is a lot of information on the www TL theory with formula and papers by a former JBL technical manager.
The first time I became aware of subjective timing issues in speakers was when I built a JBL 2245J 18" woofer based vented subwoofer from the plans in Greg Timbers' and Lorr Kramer's article in Audio magazine in the early 1980s. No matter what I tried at the time with crossover slopes, level adjustment or placement, the sub output seemed to lag that of my stacked Quad ELS mains. The sound was a sort of "kerwhoomp", with the sub subjectively trailing the mains by 1/4 second or so. Still not sure what was at work (perhaps it was stored energy in the floor), and I wish I still had these components available to have another go at implementation. Does this make me a JBL hater? Sure hope not!
Being a fully front loaded horn kind of guy for the past decade, I have had a lot of experience at blending horn subs, mid bass horns and high frequency horns. My mid bass horns have 4' to 5' added path length compared to the mids/highs, and I have yet to perceive this in terms of timing. Horns tend to sound very quick, and I think that this amount of delay falls below our threshold of perception. The phase differences through the crossover region can introduce some interesting measured response anomalies though.
It is a different story with the big horn subs. These have a path length inside the box of 18' to 20', creating delays of 10 to 15 milliseconds compared to the mid bass and mid/h.f. output. The blend is acceptable on most material, but one can tell that things don't quite line up on highly transient material like drum solos. Dialing out the arrival time errors digitally results in a noticeably more coherent sound with greater perceived impact and detail.
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