Nor Technics' first go at coaxial flats. (links are in Japanese)
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I listened to the SB-C700 at the CES in January, and preferred their sound over the LS-50 pair in our room
.Although the difference could have been down to setup and choice of partnering equipment (both rooms were equally dire acoustically), the overall impression was favourable.
I had a chat with Michiko Ogawa (Technics CEO), and she mentioned being a part of the team responsible for the SB-RX series back in the 1980s.
Probably the same is true for other members of Technics' present design and management team
Well, tell her she's my hero!
Erik
... and also the SB-R100.
It had a passive radiator ring surrounding the bass-tweeter coaxial unit. "Tri-axial".
I had a set, the foam rotted. They sounded OK.
Based on their performance I bought a set of SB-X100. They sound OK too, maybe a little bright. They miraculously haven't rotted yet.
It had a passive radiator ring surrounding the bass-tweeter coaxial unit. "Tri-axial".
I had a set, the foam rotted. They sounded OK.
Based on their performance I bought a set of SB-X100. They sound OK too, maybe a little bright. They miraculously haven't rotted yet.
Technics Premium Class SB-C700 loudspeaker Measurements | Stereophile.com
SB-C700 measured by Atkinson. TAD-level performance right there. Very wide dispersion vs TAD and KEF coaxials. As noted above, distortion is not quite KEF level above ~500Hz. However, I'm more intrigued by the dividends in dynamics from lowered compression and distortion from the larger cone. Lowered excursion + less cavity loading effect should also reduce the degree of HF modulation vs the KEF. I personally found some subtle but audible modification to treble seemingly due to the excursion.
If I'm reading it correctly, it should be noted that the LF driver does not have the voice coil directly coupled to the flat radiator (which I first expected). Rather, it is coupled to a normal cone which is then attached to the flat radiator.
SB-C700 measured by Atkinson. TAD-level performance right there. Very wide dispersion vs TAD and KEF coaxials. As noted above, distortion is not quite KEF level above ~500Hz. However, I'm more intrigued by the dividends in dynamics from lowered compression and distortion from the larger cone. Lowered excursion + less cavity loading effect should also reduce the degree of HF modulation vs the KEF. I personally found some subtle but audible modification to treble seemingly due to the excursion.
If I'm reading it correctly, it should be noted that the LF driver does not have the voice coil directly coupled to the flat radiator (which I first expected). Rather, it is coupled to a normal cone which is then attached to the flat radiator.
Woah! Let's not get too crazy because the Technics measured reasonably smooth FR, decent crossover design and better (i.e. less) energy storage. I'm actually kind of surprised the TAD's have as much ringing as they do given the magnesium and beryllium drivers.
Neither of these speakers shows the FR I would like to see though. The TAD's are too flat, and the Technics too smiley. I'm a big fan of the gentle downward slope myself, but for background and entertaining, the Technics seem to be following the trend of several $16k speaker manufacturers these days.
I wish Stereophile would update their testing though. I'd like to see some data comparing compression/distortion vs. FR and SPL. Also, I'm not in the camp that wider dispersion = better in an average setting. In my humble home, controlled dispersion is a requirement to maintain clarity of sound.
Your points about driver design, in general, are well taken though.
Best,
Erik
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I'm also in the controlled dispersion school of thought. I was just pointing out the flat radiator of the Technics + much smaller 19mm tweeter gives wider dispersion vs the TAD and KEF. In all honesty, TAD hasn't solved the issue of top-octave roughness to my knowledge; only KEF seems to have. I would put TAD and Technics in the same performance bracket at least based on FR and dispersion (which is most critical at low volumes imo as conpression and distortion is less of a concern). I expect distortion to be lower on the TAD though. KEF on the other hand has the most sophisticated coaxial, but their crossovers are in a mess.
The preference for a slight downward slope would arguably be a deal breaker with either speaker. I really wanted to like the KEF but never warmed to its balance. The Technics may be a better compromise for me; much flatter through the crucial vocal mids and from what I can tell smoother off axis. My biggest concern is the Technics' cabinet alignment, why manufacturers tune for 'chestiness' will always be a mystery. Graph splice of Stereophile's results below.
Still want to hear them though...
Attachments
It would be close to maximally flat in real life. Atkinsons's measurements are known to start peaking from about 300Hz purely due to his quasi-anechoic measurement method where he splices nearfield measurements from 300Hz down. It assumes 2pi radiation in a 4pi environment, which causes peaking up to 3-6dB higher than the actual SPL. The Technics starts peaking right from 300Hz down so it has to be that. If it was chesty the peak would be even more exaggerated.
IMO he could easily rectify that (Bagby wrote a paper on exactly that topic) but he values consistency with past measurements.
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It's really a non- issue. The listening axis shouldn't be dead-on, and the issue disappears just a little off axis.
KEF's phase plug does seem to fix it though.
You are apparently correct, at least from what I hear in my living room. These speakers go impressively deep for their size without a hint of chestiness. Technics did due diligence with the port design. Internally it faces a padded partition, perhaps explaining why no upper harmonics are audible behind the cabinet, just deep bass. It scales very well with level, sounds like a significantly larger speaker and are imaging demons. Because of my line of work my preference tends more towards studio monitor flat but off axis I don't hear excessive high end. Not bright but never mistaken for forgiving.
A big shout out from my wallet to the crazy kids at What Hi-Fi for tarnishing the market for an excellent product line, helping me buy in at a deep discount and sparing me the expense of ever picking up another copy of What Hi-Fi.
Finally got a chance to buy a pair of SB-C700
Certainly need subwoofers if they are to be placed well into the room for best imaging and air.
Yes they have a tendency to sound lean, so are Avalons and YGs (both of which I own and share the same room).
Crossover components leave a LOT of room for mods. Perhaps 2 paper-in-oil caps to sweeten the top end a bit for starters. The coax driver is essentially the mid-high used in Technics' SB-R1 which I consider to be one of the best speakers regardless of price-point.
Certainly need subwoofers if they are to be placed well into the room for best imaging and air.
Yes they have a tendency to sound lean, so are Avalons and YGs (both of which I own and share the same room).
Crossover components leave a LOT of room for mods. Perhaps 2 paper-in-oil caps to sweeten the top end a bit for starters. The coax driver is essentially the mid-high used in Technics' SB-R1 which I consider to be one of the best speakers regardless of price-point.
I should have RTFM
Correction to my previous post.
I made the assumption that the usual rule of 3rds apply to placing the speakers.
The manual stated that the best sound can be had when placed 12" to 24" from the front wall.
I finally pushed the speakers all the way back to 24" and boy what a difference. I am getting useful bass to the 40Hz region without any odd bass note standing out.
Also they seem to like high current/moderate power SS amps. OTL tubes NEED NOT APPLY.
Really happy with these guys.
Correction to my previous post.
I made the assumption that the usual rule of 3rds apply to placing the speakers.
The manual stated that the best sound can be had when placed 12" to 24" from the front wall.
I finally pushed the speakers all the way back to 24" and boy what a difference. I am getting useful bass to the 40Hz region without any odd bass note standing out.
Also they seem to like high current/moderate power SS amps. OTL tubes NEED NOT APPLY.
Really happy with these guys.
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