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Time alignment of Drivers

 
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qguy
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PostPosted: Fri May 26, 2006 1:35 am    Post subject: Time alignment of Drivers Reply with quote

I was reading a review on time aligned loudspeakers, where the drivers are not on a flat plane, but on an angled baffle. Surprisingly the KEF 105 (1977) had this feature, was this design a coincidence or time alignment was part of the original design of the 105 ?, it also makes me wonder why only the 105, 105.2 and 105.4 were "time alligned"
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ColinR
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PostPosted: Fri May 26, 2006 11:13 am    Post subject: Reply with quote

Quote:
Surprisingly
Why the surprise when talking about KEF?

Quote:
was part of the original design
There was/is a contemporary KEFTopic (Vol3 No1) dealing with the design and construction of the Ref 105.

Quote:
why only
You forgot about the Ref 107 and 107-2.

The lack of other "conventionally drivered designs" was due to rise of Uni-Q technology.
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proffski
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PostPosted: Fri May 26, 2006 1:34 pm    Post subject: Reply with quote

All very true, but if my deteriorating memory serves me right then Bang & Olufsen, Technics and Bowers & Wilkins had these designs out earlier.
The B&O sounded dreadful!
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ColinR
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PostPosted: Fri May 26, 2006 8:05 pm    Post subject: Reply with quote

Quote:
Bang & Olufsen, Technics and Bowers & Wilkins had these designs out earlier


The B&W DM 601 Embarassed was earlier, but it still used a KEF B330B bass unit Cool .

The black Technics looked the part, but was voiced for a pentatonic scale, so for background music they were fine, otherwise oooowwwooo Rolling Eyes .

Boing & Offalsound speakers were bad, which was strange as they had some SEAS drivers in at least one design Shocked .


Last edited by ColinR on Sat May 27, 2006 2:24 pm; edited 1 time in total
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proffski
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PostPosted: Fri May 26, 2006 10:08 pm    Post subject: Reply with quote

Spot on, the B&Os we heard at the London show, no idea as to which model it was, but it was the 1st one they made. It was released to the public a month or so later, never bothered listening to them again.
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qguy
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PostPosted: Fri May 26, 2006 11:57 pm    Post subject: Reply with quote

what is the spec of the b330 ?, the dm601 is a bookshelf right ?

ColinR wrote:
Quote:
Bang & Olufsen, Technics and Bowers & Wilkins had these designs out earlier


The B&W DM 601 was earlier, but it still used a KEF B330B bass unit Cool .
.
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proffski
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PostPosted: Sat May 27, 2006 1:25 am    Post subject: Reply with quote

The B&O model may have been the M70, but I'm stil unsure.
The year again may have been 1975/6. Anyway, it sounded rubbish!

Aha! Did we mean the Technics RX50EK TriAxial unit or the SB10? Or even the SB4500, SB5000, SB6000, SB7000?

I know that the ghastly SB-4500 used a paper cone tweeter. All the SB series were sold as Phase Linear, not so sure about the RX50EK though.
More to follow...

Er, surely the 1st B&W Phase Linear loudspeaker was the ugly DM6?
That would have been 1976 then. That was claimed to have been the very 1st Linear Phase loudspeaker manufactured in the UK.

Try: http://www.audiokit.it/ITAENG/UpSpeak/B&WDM6/B&WDM6.htm

Anyway, it aint a KEF...!
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ColinR
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PostPosted: Sat May 27, 2006 2:23 pm    Post subject: Reply with quote

Embarassed And the animal I was thinking of was the original 801 Shocked .

Quote:
what is the spec of the b330 ?, the dm601 is a bookshelf right


They ain't bookshelves either, very popular as "playback monitors" in recording studios.

I'm not aware of any published B330B specification sheets.
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proffski
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PostPosted: Sat May 27, 2006 2:37 pm    Post subject: Reply with quote

Hmm, the DM6 came before the superb 801. As you say, neither were bookshelf models... Cool
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ColinR
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PostPosted: Sun May 28, 2006 11:28 am    Post subject: Reply with quote

Having read both the original papers and a review of the DM6, it wasn't the sme type of animal as the Ref 105.

Linear Phase apart from marketing speak seems to describe systems in which driver voice coils are equidistant from an (arbitrary?) acoustic centre, somewhere along a line from this point is where measurements were made. Such designs can have interesting off axis resonses.

Time Aligned designs have drivers' voice coils aligned in a plane giving better polar and impulse responses, but may have problems with an individual driver's phase response.

Confused Shocked , well instead of reading this you could always go and listen to some music. Using KEF speakers of course Very Happy .
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centaurus
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PostPosted: Mon Jul 24, 2006 5:55 am    Post subject: Don't forget Thiel! Reply with quote

Don't forget Thiel!

i have a pair of mid 1980's Thiel 03A Coherant Source loudspeakers. angled baffle with Polydax drivers. incredible sounding. i do believe my 104/2 with the tweeter issues figured out, will be more than a match for them though.

both are keepers.

see ya,
Roby
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ColinR
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PostPosted: Mon Jul 24, 2006 7:24 pm    Post subject: Reply with quote

Thiel, hmmmmm.

I suspect the numbers of examples in the U.K. will be a function of the numbers of base commanders at Mildenhall or any other U.S.A.F. base with access to C-141 Starlifters.

The slightly larger numbers of Bozaks and Advents, were for those lower down in the U.S. military food chain.
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