Hello,
Seems that Chinese replicate the RCA 1428:
http://www.lmaudio.net/html/lmaudio.html#
A Google antomatic translation gives:
"China's first excitation Alto Drive - 1428
- The RCA-1428 as a blueprint for a perfect reproducibility
- 1937 RCA to RCA-1428 produced the perfect "blueprint" to reproduce
- Using pure iron magnetic circuit, magnetic field excitation.
- Use the large 5.5-inch phenolic diaphragm,
- The unique design of turbine-type phase plug
- Equipped with 1.5-inch and 2 inch hose then (with ALTEC / JBL horn with such access)
Technical Data - Frequency Response: Bandwidth 400HZ-12kHz, (then 22A horn test 150HZ-10kHZ)
Sensitivity: 100dB, Impedance: 16Ω, Excitation: 300V / 60mA "
Best regards from Paris, France
Jean-Michel Le Cléac'h
Seems that Chinese replicate the RCA 1428:
http://www.lmaudio.net/html/lmaudio.html#
A Google antomatic translation gives:
"China's first excitation Alto Drive - 1428
- The RCA-1428 as a blueprint for a perfect reproducibility
- 1937 RCA to RCA-1428 produced the perfect "blueprint" to reproduce
- Using pure iron magnetic circuit, magnetic field excitation.
- Use the large 5.5-inch phenolic diaphragm,
- The unique design of turbine-type phase plug
- Equipped with 1.5-inch and 2 inch hose then (with ALTEC / JBL horn with such access)
Technical Data - Frequency Response: Bandwidth 400HZ-12kHz, (then 22A horn test 150HZ-10kHZ)
Sensitivity: 100dB, Impedance: 16Ω, Excitation: 300V / 60mA "
Best regards from Paris, France
Jean-Michel Le Cléac'h
Okay, 120 views so far and no replys. I guess I'll be the first to bite on this.
It looks like a nice reproduction piece. I like the use of the phenolic diaphragm over that carbon fiber one that Cogent uses. The big question is what kind of cost is it, and how do you purchase them?
Rgs, JLH
Cogent carbon fiber cone below.
It looks like a nice reproduction piece. I like the use of the phenolic diaphragm over that carbon fiber one that Cogent uses. The big question is what kind of cost is it, and how do you purchase them?
Rgs, JLH
Cogent carbon fiber cone below.
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LIST PRICE (about 20% off at dealers):
HT-70 (WE 597) is RMB 26000/pair (includes supply)
555 is RMB 13000/pair
1428 is RMB 22000/pair
BA-15 is RMB 20000/pair
22A Horn is RMB 26000/pair
You can try calling their Canadian distributor for English info...
LOYALTY SOUND LTD.
ALBERT YEUNG
(403)-2448838
1107-8TH STREET S.W.CALGARY,ALBERTA T2R 1L4
HT-70 (WE 597) is RMB 26000/pair (includes supply)
555 is RMB 13000/pair
1428 is RMB 22000/pair
BA-15 is RMB 20000/pair
22A Horn is RMB 26000/pair
You can try calling their Canadian distributor for English info...
LOYALTY SOUND LTD.
ALBERT YEUNG
(403)-2448838
1107-8TH STREET S.W.CALGARY,ALBERTA T2R 1L4
The LineMangetic Audio Design Lab product line were made known to a larger public a year ago through Srajan Ebaen, when he visited the Guangshou Audio Show. Out of curiosity, i contacted the company twice to know prices , but no response. Also their Canada importer and distributor didn't answer any email.
their field coil bass compression driver is unique indeed :
some more pictures and links at my forum :
http://www.audiovoice-acoustics.com/forum/showthread.php?t=585
l
their field coil bass compression driver is unique indeed :
some more pictures and links at my forum :
http://www.audiovoice-acoustics.com/forum/showthread.php?t=585
l
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The LineMangetic Audio Design Lab product line were made known to a larger public a year ago through Srajan Ebaen, when he visited the Guangshou Audio Show. Out of curiosity, i contacted the company twice to know prices , but no response. Also their Canada importer and distributor didn't answer any email.
their field coil bass compression driver is unique indeed :
some more pictures and links at my forum :
LineMagnetic Audiodesign Lab - Audio Voice Acoustics
l
the guy who run it probably couldn't speak english.
saw some of their stuff on local forums, seems legit 
If looks is all you care about, just build yourself some metal cabinets with some glowing tubes and have some Class D amps on the inside so at least they sound great. Lots cheaper than buying that stuff I assure you.
Okay, 120 views so far and no replys. I guess I'll be the first to bite on this.
It looks like a nice reproduction piece. I like the use of the phenolic diaphragm over that carbon fiber one that Cogent uses. The big question is what kind of cost is it, and how do you purchase them?
Rgs, JLH
Cogent carbon fiber cone below.
Other than a phase plug, and some field coil magic, the DS-1428's diaphragm looks like the cone midrange in the B&W 802 speaker, which sounds like a toy next to a horn speaker with metal dome compression drivers.
I think this is just a contribution to the discussion about using cone drivers only in a horn system, instead of a compression driver with a metal dome diaphragm.
In general, cone drivers sound dull so I keep them for subs and lower midrange - away from any range that require pristine detail.
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Cogent diaphragms
The Cogent diaphragms may look like direct radiator cones but they are not. They are compression driver diaphragms. The Cogents are basically modern versions of the 1930's vintage RCA 1428 field coil compression drivers. I have never heard the Cogents but the designer/maker Steve Schell says they sound better than the original 1428 and I believe him (they damn well *should* sound better considering the build quality and the price). I have heard original RCA 1428s on RCA horns and they sound very very good, very smooth but quite detailed, without the irritating metallic quality of metal domes. The RCA 1428's range is 300 Hz to ~10kHz. The early diaphragms are treated paper, later diaphragms are phenolic coated fabric, both have chamois (goat) leather perimeter surrounds and mount to the driver with a screw in the center (+perimeter mounting screws). Another modern version of the 1428 is the B&C DCM50. I have a pair of DCM50s on Acoustic Horn Company AH300s and they sound great, far better than JBL 375s on 300 Hz tractrix horns.
The Cogent diaphragms may look like direct radiator cones but they are not. They are compression driver diaphragms. The Cogents are basically modern versions of the 1930's vintage RCA 1428 field coil compression drivers. I have never heard the Cogents but the designer/maker Steve Schell says they sound better than the original 1428 and I believe him (they damn well *should* sound better considering the build quality and the price). I have heard original RCA 1428s on RCA horns and they sound very very good, very smooth but quite detailed, without the irritating metallic quality of metal domes. The RCA 1428's range is 300 Hz to ~10kHz. The early diaphragms are treated paper, later diaphragms are phenolic coated fabric, both have chamois (goat) leather perimeter surrounds and mount to the driver with a screw in the center (+perimeter mounting screws). Another modern version of the 1428 is the B&C DCM50. I have a pair of DCM50s on Acoustic Horn Company AH300s and they sound great, far better than JBL 375s on 300 Hz tractrix horns.
Hello Kerry, I like what you say about the DCM50. Have you ever had the low compression Community Light & Sound M200a or the JBL CMCD paper compression drivers? I also find them remarkably better than the traditional metal dome compression drivers, (JBL, Radian, TAD ect) especially in the midrange. To me they sound quieter (less noise) smoother and much less artificial.
Hi POOH, I have not tried the drivers you mentioned, they both look interesting, especially the JBL CMCD, which really does look like a conventional direct radiator in a compression-type housing. My experience is with vintage drivers mostly; I always liked the sound of old Jensen and EV drivers with phenolic diaphragms; "quieter, smoother and much less artificial" as you say (but the paper cone B&Cs sound much better). Years ago I found a pair of JBL 2482s at a flea market and I liked those too, nice mid/upper bass but they needed tweeters badly (wonder how 2482s sound with the 2470 1" drivers with phenolic diaphragms). I regret selling the 2482s, think they could work well in a home system. My 375s were frustrating, I was always bothered by the slightly tizzy, metallic sound even though I really liked them overall. Anyhow, I am satisfied with the B&Cs, my system sounds more realistic now. Something that really stands out to me about the DCM50s is how much easier it is now to clearly understand lyrics and hear really-low level detail.
Hi Pano,
I was using 375s when I found the 2482s and in comparison the JBL phenolic drivers sounded quite different, lots more low end, much smoother midrange and way less highs. Vocals and spoken voice sounded more realistic. Same thing basically with Jensen drivers in Imperials and EV drivers in a Patrician; in comparison 375s+077s in Hartsfields sound slightly tizzy, metallic. To compare paper 'cones' to aluminum domes I left one side of my stereo setup as it was and replaced the JBL driver+tractrix horn on the other side with a B&C DCM50+AH300 conical horn. I was able to play one side at a time using mono sources and the B&C+AH300 was far more to my liking. Less distorted, more detailed. I also listened to the DCM50 without a horn FWIW and it sounded great that way too, not much different, except for a bit less bass than it has on the AH300. Admittedly phenolic drivers do sound sort of soft, but the treated paper cones in my DCM50s do not sound soft, just smooth. And detailed. Dynamic. And they image like crazy by the way.
I was using 375s when I found the 2482s and in comparison the JBL phenolic drivers sounded quite different, lots more low end, much smoother midrange and way less highs. Vocals and spoken voice sounded more realistic. Same thing basically with Jensen drivers in Imperials and EV drivers in a Patrician; in comparison 375s+077s in Hartsfields sound slightly tizzy, metallic. To compare paper 'cones' to aluminum domes I left one side of my stereo setup as it was and replaced the JBL driver+tractrix horn on the other side with a B&C DCM50+AH300 conical horn. I was able to play one side at a time using mono sources and the B&C+AH300 was far more to my liking. Less distorted, more detailed. I also listened to the DCM50 without a horn FWIW and it sounded great that way too, not much different, except for a bit less bass than it has on the AH300. Admittedly phenolic drivers do sound sort of soft, but the treated paper cones in my DCM50s do not sound soft, just smooth. And detailed. Dynamic. And they image like crazy by the way.
Hi Bare,
I am not gullible, I'm a natural born skeptic, eh. I have directly compared aluminum dome drivers (JBL 375s and Altec 288s ) to my various phenolic compression drivers ( EV, Jensen ) and to my paper cone compression drivers ( B&C DCM50s. It's super easy to hear the difference, even using the crossovers, amps, bass horns and tweeters. You've never noticed that aluminum and other types of metal drivers sound 'metallic' ? That metallic sound is really obvious to me. Apparently the new beryllium diaphragms sound better, not so tizzy, but I doubt they sound as good as my paper diaphragm drivers.
I am not gullible, I'm a natural born skeptic, eh. I have directly compared aluminum dome drivers (JBL 375s and Altec 288s ) to my various phenolic compression drivers ( EV, Jensen ) and to my paper cone compression drivers ( B&C DCM50s. It's super easy to hear the difference, even using the crossovers, amps, bass horns and tweeters. You've never noticed that aluminum and other types of metal drivers sound 'metallic' ? That metallic sound is really obvious to me. Apparently the new beryllium diaphragms sound better, not so tizzy, but I doubt they sound as good as my paper diaphragm drivers.
Thanks Kerry, I'm with you on the different sounds from different materials used for the diaphragms. I have found there are good and bad in the different types. For example I always hated the raspy break up of titanium until I heard Selenium large format D405ti. They are stated as being "Its pure titanium diaphragm was especially designed based on the extremely light and structurally strong snowflake crystal" - they are really smooth bettering the JBL 2440. I still have a pair i won't part with.
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