We asked Senior Product Manager Mike Gough about the technology used within the new CM10 speaker starting off with the all-important tweeter-on-top question:
• CM10 is the first speaker in the CM Series to use a tweeter-on-top configuration. What advantages does that approach offer?
In any loudspeaker, the narrower the enclosure compared to the driver’s diaphragm, the wider and more consistent with frequency the dispersion becomes. Look at any CM-Series loudspeaker and you’ll notice that the sides of the main cabinet are as close as possible to the bass and midrange drivers. We do that because it improves imaging and reduces any change in sound character for listeners not in the central ‘hot seat’.
It’s a natural progression for us to treat the tweeter the same way, which is why we have introduced a tweeter-on-top housing to CM10. Not only does imaging improve, but the sound gains a more ‘out of the box’ quality.
You’re more aware of a truly three-dimensional sound and less of where the speakers are in the room.
• Any other advantages to this configuration?
Drive units can very easily excite resonances in the structure of the cabinet within which they’re mounted. We want to prevent vibration travelling from one drive unit to another, so in CM10 the tweeter is compliantly mounted from its housing. Then the housing itself is compliantly mounted from the main body of the cabinet. It’s a very effective decoupling system.
• Is the tweeter itself the same as with other CM Series speakers?
No the CM10 uses a new design, inspired by the research we conducted on the Carbon Braced Tweeter employed in our PM1 loudspeaker. Here, we’ve strengthened the edge of the aluminium dome using a second aluminium layer that replicates the main dome’s profile with the centre part cut out. This gives us a new Double Dome design.
• What does the Double Dome Tweeter do for performance?
The Double Dome pushes the first break-up frequency up from the 30kHz of our standard dome to 38kHz in the new design. This makes the tweeter purer and more piston-like in the all-important audible band below 20Hz. The result is exceptional clarity and control, even under duress.
• What else is new in CM10?
Another advantage of the change in tweeter configuration is that, within the same overall height of our CM9 loudspeaker, we’ve managed to get in a third bass driver, giving us both improved sensitivity and enhanced low-frequency response. Put that another way: in CM10, we’ve got the ability to both play louder, and to deliver less audible distortion when doing so.
CM10 also features an FST midrange drive unit as in the CM9, but here the FST drive unit is decoupled using a supporting rod anchored at the back of the cabinet, much as in an 800-Series loudspeaker. This compliant mounting mechanism stops unwanted vibrations from the moving diaphragm getting into the drive unit, delivering a cleaner, less coloured sound.