This is a review and detailed measurements of the Technics SB-C700 coaxial 2-way bookshelf speaker. It is on kind loan from a member and costs US $1,699.
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The enclosure is built quite solid and the paint job is first class. Not that it matters but I was surprised to see no marking on the back as to model and manufacturing location:
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Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.
Reference axis was the center of the tweeter (aligned by eye). Measurement room was at 10 degrees C which may lower bass output a bit. Accuracy is better than 1% in most of the frequency spectrum but degraded to 2% above 5 KHz indicating complex interference from multiple sources .
Technics SB-C700 Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
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On axis is surprisingly good. Yes, there are a few resonances but overall, it is quite flat. The closes competitor to SB-C700 is the
KEF LS50. Here is its spin:
Quite on even and worse than Technics.
Port is tuned to lower frequency and hence creates a shelf there:
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Cabinet resonance around 1.4 kHz is visible but at much lower level than we see in budget ported speakers. Still, as noted you can see it cause a dB or so peaking in on-axis response.
Early window reflections have high similarity to on-axis response due to excellent directivity:
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There is a broad dip though which is also reflected in predicted in-room response:
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Beam width is wide and generally smooth:
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Same story with directivity:
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Due to coaxial driver, vertical response is almost the same:
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Distortion is kept in check at 86 dBSPL but gets out of control at 96 dBSPL:
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Impedance is on the low side but then again, this is a similar story to many small speakers:
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For fans of timing analysis, here are those measurements:
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Technics SB-C700 Listening Tests
First impression was that the tonality was correct. Yet track after track did not impress. Some sounded a bit tubby, some a bit bright. Both of these were indicated in the measurements but correcting them didn't improvement things. So switched out the speaker with Revel M105. Wow, oh wow! The sound was so much more detailed, open and delightful than what I was getting out of Technics. So I pulled out the predicted in-room response of the M105 and saw this perfection:
In comparison, the SB-C700 has that broad dip. I put in a quick and dirty boost there and improvement was substantial:
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I have noticed the same in countless headphone measurements. Make this region right and the sound opens up with better detail and spatial qualities. Now, I could sit back and enjoy the sound of the Technics!
Conclusions
The SB-C700 made quite a buzz on its release circa 2015. Panasonics (parent of Technics) had existed TV business but was getting seriously back into audio and this was their entry. I remember hearing it though at an audio show and walked away unimpressed. Part of it was the poor demo but now that I have listened to it, I can see that it is so close to being an excellent speaker. Objectively it is far better than KEF LS50 which has run away with this market that could have been Panasonic's. Sadly I think the SB-C700 is being discontinued, likely due to zero marketing.
As is, even though objective performance is very good, I personally can't recommend the Technics SB-C700. Add a bit of EQ to it though and it becomes a very capable speaker that I can recommend.
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