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B&C DCX464
B&C DCX464
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Old 22nd June 2019, 12:06 PM   #31
Droco is offline Droco
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Does anyone know of any comparison with the BMS drivers yet? Primarly quality.

And secondly, am I correct to assume the B&C will be even more powerfull dB wise compared to the BMS? Not by a lot, but sensitivity looks to be a little bit better than the BMS 110dB (based on the graphs).

Maarten
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Old 22nd June 2019, 12:12 PM   #32
pk is offline pk  Denmark
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Ji Jzagaja,

I asked the people at B&C, and the exit angle is zero.

Best regards
Peter

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Do we know dcx464 exit angle?
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Old 24th June 2019, 11:36 AM   #33
Sean Custer is offline Sean Custer
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Default B&C DCX464

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Originally Posted by Joseph Crowe View Post
65mm is too big a voice coil for high frequency in a domestic audiophile setting. There will be diaphragm breakup well before 10kHz. That rules it out for me.
It’s tough to find a small format CD that has good extension, let alone a large format.
The B&C DCX464 65mm diaphragm is a ring radiator not a typical dome diaphragm like in a compression driver. The ring allows a larger voice coil on a diaphragm that has less surface area than the same diameter dome diaphragm. Less area less mass less mass equals more high frequency extension & better transients. As far as using these for a home audiophile setting i never would due to the word coaxial. That rules it out for me.
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Old 3rd July 2019, 07:01 PM   #34
Joseph Crowe is offline Joseph Crowe  Canada
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Originally Posted by Sean Custer View Post
The B&C DCX464 65mm diaphragm is a ring radiator not a typical dome diaphragm like in a compression driver. The ring allows a larger voice coil on a diaphragm that has less surface area than the same diameter dome diaphragm. Less area less mass less mass equals more high frequency extension & better transients. As far as using these for a home audiophile setting i never would due to the word coaxial. That rules it out for me.
Yeah I see that now. The OP used the term “annular” so I was thinking tangerine phase plug like the Altec 802.
I prefer horn loaded planar or front horn loaded small fullrange for wide bandwidth IMHO.
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Old 3rd July 2019, 07:52 PM   #35
300Z is offline 300Z  Brazil
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Quote:
Originally Posted by Sean Custer View Post
The B&C DCX464 65mm diaphragm is a ring radiator not a typical dome diaphragm like in a compression driver. The ring allows a larger voice coil on a diaphragm that has less surface area than the same diameter dome diaphragm. Less area less mass less mass equals more high frequency extension & better transients. As far as using these for a home audiophile setting i never would due to the word coaxial. That rules it out for me.
Can you tell us what's the problem in a coaxial driver like this? What exactly makes it a less than ideal driver?
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Old 7th July 2019, 04:47 AM   #36
Joseph Crowe is offline Joseph Crowe  Canada
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Originally Posted by 300Z View Post
Can you tell us what's the problem in a coaxial driver like this? What exactly makes it a less than ideal driver?
Since nobody is responding to you I'll take a shot at it. Since we don't know much about the B&C DCX464 I can look at something similar which is the BMS 4507ND. The problem has always been with the co-entrant design where the high and mid frequencies have to combine somehow without causing the high frequency wavefront to encounter an abrupt physical change in the pathway curvature. Usually the high frequency sound wave has to "jump" a physical gap. This causes higher order harmonics to form which effects the performance of the driver in the time domain. Evidence of this can be seen in a CSD waterfall plot of the BMS 4507ND compared against a regular compression driver such as the B&C DE360. As you can see the DE360 exhibits much better Spectral decay performance than the 4507ND.
I hope this helps!

The attached images were pulled from the following links...
Test Bench: BMS 4507ND Dual Diaphragm Coaxial Planar Wave Driver | audioXpress
Test Bench: B&C Speakers DE360-8 1” Exit Pro Sound Compression Driver | audioXpress
Attached Images
File Type: jpg CSD BMS.JPG (54.7 KB, 188 views)
File Type: jpg CSD BnC.JPG (58.1 KB, 186 views)

Last edited by Joseph Crowe; 7th July 2019 at 04:51 AM.
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Old 7th July 2019, 01:20 PM   #37
300Z is offline 300Z  Brazil
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Thank you!
I understand the issues with a normal coaxial driver but I had seen test results for the BMS unit.
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Old 11th July 2019, 05:37 PM   #38
Bennett Prescott is offline Bennett Prescott  United States
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B&C DCX464
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Originally Posted by Joseph Crowe View Post
The problem has always been with the co-entrant design where the high and mid frequencies have to combine somehow without causing the high frequency wavefront to encounter an abrupt physical change in the pathway curvature. Usually the high frequency sound wave has to "jump" a physical gap. This causes higher order harmonics to form which effects the performance of the driver in the time domain.
We have mitigated this with our (patent pending) midrange filter, which makes the MF path look very high impedance to the HF driver and filters the higher response of the MF driver so it doesn't resonate in the HF cavity.

FYI, these drivers should be available around the end of August in the US. Maybe sooner elsewhere. List price in the US is $1062.
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Old 13th July 2019, 12:25 PM   #39
Joseph Crowe is offline Joseph Crowe  Canada
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Originally Posted by Bennett Prescott View Post
We have mitigated this with our (patent pending) midrange filter, which makes the MF path look very high impedance to the HF driver and filters the higher response of the MF driver so it doesn't resonate in the HF cavity.

FYI, these drivers should be available around the end of August in the US. Maybe sooner elsewhere. List price in the US is $1062.
Wow that sounds interesting. What relation do you have with B&C? Do you know if AudioXpress will be doing a test review?
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Old 13th July 2019, 12:35 PM   #40
cowanaudio is offline cowanaudio  Australia
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What relation do you have with B&C?
B&C Sales & Operations Director – North America

See B&C Speakers
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