JBL Array 2235 Be project
- Thread starter cooky1257
- Start date
Hi Joel,
Mmmm, they are pistonic to 15khz, anything past 14khz is not the best uhf around tbh hence the tiny 045be/ti comp drivers.
I actually roll them off above 13.5khz(@24dB/0ct).
Dev;
bottleneck
talks a load of rubbish
Hi Cooky
you know, every comp. driver Ive had in my house (vitavox (briefly) Altec, Tannoy now TAD begins to roll off about 14khz.. do you think it's indemic to the breed?
I thought about the TAD berrilium supertweeters until I found out how much they cost and turned as purple as a goosebury !
Using JBL 2405, which is a lovely tweeter, best for the money IMO, if not SOTA in comparison with multi thousand pound comp. tweeters.
you know, every comp. driver Ive had in my house (vitavox (briefly) Altec, Tannoy now TAD begins to roll off about 14khz.. do you think it's indemic to the breed?
I thought about the TAD berrilium supertweeters until I found out how much they cost and turned as purple as a goosebury !
Using JBL 2405, which is a lovely tweeter, best for the money IMO, if not SOTA in comparison with multi thousand pound comp. tweeters.
i_should_coco
Monkey
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Pretty much, yeah. Anything above that is down to resonance and will sound pretty shit.
Well the 435 Be was allegedly a breakthrough in getting a non resonance enhanced response out to 15khz but see this from JBL, the new S9900 http://www.audioheritage.org/vbulletin/showthread.php?p=252245
If you look at the response the uhf is just a super tweeter, the new 4" 476Mg unit runs in parallel out past 20khz. This is the magnesium diaphragm version of the 476 the other is 476Be as used in the Everest DD66000.
I liked the 2405 bat killer too!
If you look at the response the uhf is just a super tweeter, the new 4" 476Mg unit runs in parallel out past 20khz. This is the magnesium diaphragm version of the 476 the other is 476Be as used in the Everest DD66000.
I liked the 2405 bat killer too!
joel
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Looking forward to seeing what happens when you add the UHF driver. Will you get the JBL dip?
Anyway, compare what you've got with the reality circa 1980
Or even an early exclusive / TAD, model 3401:
I'd be happy just letting it roll off at the top. Of course adding UHF is fine, just as long as you can't hear it ;-)
Those curves remind me of Greg Timbers' comment re the design shortcomings of the legendary JBL 4350 monitor, it goes along the lines of ;" no one told the 4350 it shouldn't work and so it does anyway!"
Lots of manufacturers mislead and use single octave smoothing in their published response curves-those look very honest to me and as far as I know those Tad exclusives and JBL's sound wonderful. Peaks are nasty, dips are harder to detect.
The ideal is to run 2 way, my own lugs are only good up to 13.5-14k anyway. the dip will come as it is an on axis comb filtering effect down to the hf driver locations- off axis and so realistically in-room, it is inaudible/masked-but we shall see.
cooky
Lots of manufacturers mislead and use single octave smoothing in their published response curves-those look very honest to me and as far as I know those Tad exclusives and JBL's sound wonderful. Peaks are nasty, dips are harder to detect.
The ideal is to run 2 way, my own lugs are only good up to 13.5-14k anyway. the dip will come as it is an on axis comb filtering effect down to the hf driver locations- off axis and so realistically in-room, it is inaudible/masked-but we shall see.
cooky
joel
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The measurements were made by Japanese journal Musen to jikken (M&J Journal) in an excellent 1980 book "Future Monitor Speakers". Of course there really was No Future, but it was fun to dream.
Here are some Altecs...
Diatone (Mitsubishi) AS3002, essentially NHK's (Japan's BBC) monitor speaker from the late 1950s (!!!) until the early 1990s
This speaker, unknown outside of Japan, is one of the finest tranducers ever made IMHO. Superb.
Here are some Altecs...
Diatone (Mitsubishi) AS3002, essentially NHK's (Japan's BBC) monitor speaker from the late 1950s (!!!) until the early 1990s
This speaker, unknown outside of Japan, is one of the finest tranducers ever made IMHO. Superb.
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More info on the drivers
Some more background on the comp drivers: http://www.audioheritage.org/html/projectmay/technology/045be.htm
http://www.audioheritage.org/html/projectmay/technology/435be.htm
Some more background on the comp drivers: http://www.audioheritage.org/html/projectmay/technology/045be.htm
http://www.audioheritage.org/html/projectmay/technology/435be.htm
http://www.truextent.com/ are now making aftermarket beryllium dias available to general public, they are starting with the 4"'s and will release other 3 and 2" replacements later this year.
bottleneck
talks a load of rubbish
Hi Cooky
Do you know if Truextent make a berrillium diaphragm compatible with the TAD 400/1/2/3 ?
If so, I would be interested to know how much these cost for potential future purchases (not now, by any means, but future)
Do you know if Truextent make a berrillium diaphragm compatible with the TAD 400/1/2/3 ?
If so, I would be interested to know how much these cost for potential future purchases (not now, by any means, but future)
Hi Chris,
The TAD's are vapour deposition Be the Truextent(who make the dias for jbl)are solid foil Be so I couldn't say-I'd email them and ask as the 4000 series is pretty much a 375/2440 with redesigned phase plug. The prices are $730 each for the 4" dias.More info here http://www.electrofusionproducts.com/display_page.asp?page_id=1
Cooky
The TAD's are vapour deposition Be the Truextent(who make the dias for jbl)are solid foil Be so I couldn't say-I'd email them and ask as the 4000 series is pretty much a 375/2440 with redesigned phase plug. The prices are $730 each for the 4" dias.More info here http://www.electrofusionproducts.com/display_page.asp?page_id=1
Cooky
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bottleneck
talks a load of rubbish
thanks cooky.
Do you know how much they are going for? Cant see any prices on the web.
Cheers
Chris
Do you know how much they are going for? Cant see any prices on the web.
Cheers
Chris
bottleneck
talks a load of rubbish
yowch
!!
still cheaper than the originals.
!!
still cheaper than the originals.
Behringer-electric(no not that behringer!) are now distributing the 4" Brush Wellman Beryllium dias @ only €500 each
http://www.behringer-electric.de/index.php?option=com_content&view=article&id=86&Itemid=101
http://www.behringer-electric.de/index.php?option=com_content&view=article&id=86&Itemid=101
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I've been researching a possible mod to my bass driver-basically convert a 2235 to a 2234 to reduce cone mass and increase the resonant frequency slightly and watching an amusing thread elsewhere about speakers that 'do 20hz'.
My reservations and observations of the power and excursion limitation at VLF fell on deaf ears somewhat but as it related to my own design and the approach of Greg Timbers in rolling the bass of early to allow for room placement I uncovered these graphs that shocked even me-and I thought I had the extent of these VLF 'limitations' understood.
Bear in mind this is professional drivers representing pretty much close to state of the art.
Look at the max power input at vlf, in a high power driver it's down to only a few watts!
The excursion is also a real eye opener.
With this in mind and thanks to the convenience of DSP I'm now running with a steep lf filter below 30 hz.The benefits are clearly audible.
My reservations and observations of the power and excursion limitation at VLF fell on deaf ears somewhat but as it related to my own design and the approach of Greg Timbers in rolling the bass of early to allow for room placement I uncovered these graphs that shocked even me-and I thought I had the extent of these VLF 'limitations' understood.
Bear in mind this is professional drivers representing pretty much close to state of the art.
Look at the max power input at vlf, in a high power driver it's down to only a few watts!
The excursion is also a real eye opener.
With this in mind and thanks to the convenience of DSP I'm now running with a steep lf filter below 30 hz.The benefits are clearly audible.
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