Are any of the "clones" using the 2234H or dual 2235H's? Maybe
the "broad bump between 200Hz - 300Hz" was a problem that
JBL addressed by using the 2234H to limit the "2235H's from contributing too much mid bass".
Are any of the "clones" using the 2234H or dual 2235H's? Maybe
the "broad bump between 200Hz - 300Hz" was a problem that
JBL addressed by using the 2234H to limit the "2235H's from contributing too much mid bass".
JBL built the 4355 with dual 2235s and the 4435 with dual 2234s concurrently. They are different design philosophies and some prefer the former and others the latter. In the case of the 4435, the use of the 2234 woofer does not solve the midrange peak problem, their crossover does. It is designed to only allow both woofers work in tandem below about 100Hz, above that the woofer directly below the HF unit becomes the sole driver with increasing frequency.
Here is the excerpt the describes the situation I am talking about with a large cone mid driver and a 15" woofer, or in the case of the 4355 a pair of 15" woofers. JBL recommends the same special active crossover card for both the 4345 (an updated big brother to the 4343) and the 4355.
Yet another voltage drive
OK, a challenge for you, if you're in a goofy enough mood for it. You're the only one I know could get it done...Originally posted by Giskard
Yet another voltage drive
Can you show the two cases of, say, either the 4343 or 4345, in biamp mode with the LF and "others" both in phase and in opposite phase (polarity)?
I'm dang curious how much of the troublesome summing is obviated by having the LF and low-MF out of phase.
Pretty please?
We need a smily face for a dog barking up a tree...
bo
"Indeed, not!!"
I'll add on to Bo's question, does anyone have an idea why JBL would design the 4345 with the 10" mid with reversed polarity and the 4355 with it's 12" mid in correct polarity?
The one difference that I can think of is that the 4355 is ALWAYS bi-amped.
My guess would be that it has to do with the lengths of the horns. I think one is 4" longer than the other.Originally posted by Mr. Widget
I'll add on to Bo's question, does anyone have an idea why JBL would design the 4345 with the 10" mid with reversed polarity and the 4355 with it's 12" mid in correct polarity?
The one difference that I can think of is that the 4355 is ALWAYS bi-amped.
Very close...Originally posted by Giskard
My guess would be that it has to do with the lengths of the horns. I think one is 4" longer than the other.
If the brochures can be trusted the 2307 is 7-3/4in and the 2311 is 4-5/8in (4345 and 4355, respectively), for difference of 3-1/8in.
So, whaddya think - is it possible to model the 4343/4345 biamped, and see the effect of opposing the phasing? Or should I
I'm still marvelling in the improvement of the new diaphragms for the 2421B's. I'm willing to try ANYTHING
bo
"Indeed, not!!"
Holy smokes! :shock:
That'd be that 4343 255Hz "bump" the Widget was referring to, eh?
Busy boy/girl, Giskard...
bo
"Indeed, not!!"
Bo, those are phase angle plots, not frequency plots.
I realize that, but I'm trying to understand if that phasing is contributing to the "bump". Whaddya think?Originally posted by Mr. Widget
Bo, those are phase angle plots, not frequency plots.
bo
"Indeed, not!!"
You're being goofy...Originally posted by Giskard
You guys know each other?
But I've laughed at the other post, all morning. I have no clue what that meant.
bo
"Indeed, not!!"
" I realize that, but I'm trying to understand if that phasing is contributing to the "bump". Whaddya think?"
I don't think that it is that simple of a relationship that one can infer one from the other.
In any event, I think the girl/boy with bread breath is far more amusing.
Use an RTA and find out.Originally posted by boputnam
OK, a challenge for you, if you're in a goofy enough mood for it. You're the only one I know could get it done...
Can you show the two cases of, say, either the 4343 or 4345, in biamp mode with the LF and "others" both in phase and in opposite phase (polarity)?
I'm dang curious how much of the troublesome summing is obviated by having the LF and low-MF out of phase.
Widget? Are you game? I'll run wires and sling beers.Originally posted by Giskard
Use an RTA and find out.
Closest I'll get to Tahiti...
bo
"Indeed, not!!"
Yeah,
And Mr Widget we wanna an email/post card from Tahiti please.
Ian
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