Audio T Verdict
The Bowers & Wilkins CCM664SR is an unusually flexible in-ceiling speaker that can reproduce stereo sound from a single installation position or operate as a conventional surround channel.
Two offset soft-dome tweeters reproduce the left and right high-frequency channels, while the twin-voice-coil 150mm glass-fibre driver handles both channels through one shared bass and midrange cone.
It is ideal for smaller rooms where installing a conventional stereo pair is impractical, but its dual-channel wiring and stereo/surround switch need to be planned correctly before installation.
Bowers & Wilkins CCM664SR Dual-Channel In-Ceiling Speaker
The CCM664SR is a dual-channel, two-way in-ceiling loudspeaker from the Bowers & Wilkins Performance Series.
Unlike a conventional ceiling speaker, it contains two 20mm soft-dome tweeters and a 150mm woven glass-fibre bass and midrange driver with two separate voice coils.
This allows one CCM664SR to reproduce both the left and right channels of a stereo system without discarding either side of the recording.
Supplied Individually
The CCM664SR is supplied and priced as one in-ceiling speaker.
One speaker can reproduce both stereo channels, or multiple CCM664SR speakers can be used as individual surround channels within a home cinema system.
Single-Speaker Stereo
In Stereo mode, separate left and right amplifier channels connect to the corresponding terminals on the CCM664SR.
Each channel feeds one soft-dome tweeter and one of the two voice coils within the shared bass and midrange driver.
This allows both channels of a stereo recording to be heard from one ceiling position, making the speaker useful where there is insufficient space for a correctly separated stereo pair.
Where Single-Speaker Stereo Works Best
The CCM664SR is particularly useful in smaller rooms and secondary listening areas where a conventional pair of speakers would be difficult to position.
Suitable applications may include:
- Bathrooms and en-suites
- Small kitchens
- Hallways and landings
- Dressing rooms
- Utility rooms
- Compact bedrooms
- Small studies
- Individual multi-room audio zones
A single dual-channel speaker cannot create the same physical left-to-right soundstage as two widely separated speakers, but it allows the complete stereo signal to be heard from one discreet position.
Stereo and Surround Switch
A two-position switch allows the CCM664SR to be configured for Stereo or Surround operation.
In Stereo mode, the left and right channels remain separate and are reproduced through the two tweeters and twin bass-driver voice coils.
In Surround mode, the speaker operates as one surround or overhead channel within a multichannel home cinema system.
Set the Switch Before Final Assembly
Confirm whether the speaker will be used for single-speaker stereo or as a surround channel before the speaker baffle and grille are installed.
The amplifier should be switched off before changing connections or altering the speaker’s operating mode.
Twin Soft-Dome Tweeters
Two offset 20mm soft-dome tweeters reproduce the high frequencies.
In Stereo mode, one tweeter handles the left channel while the other handles the right channel.
The offset arrangement helps distribute the two channels across the room rather than placing both tweeters at exactly the same point.
Twin-Voice-Coil Glass-Fibre Driver
A 150mm woven glass-fibre cone handles the bass and midrange frequencies.
The driver contains two separate voice coils, allowing the left and right amplifier channels to operate through one shared cone.
Woven glass fibre combines useful rigidity with controlled behaviour, helping the CCM664SR reproduce vocals, instruments and sound effects with clarity and consistency.
Surround and Overhead Use
When switched to Surround mode, the CCM664SR can be used as one channel within a compatible home cinema system.
This makes it suitable for surround, rear or overhead effects where broad coverage is more important than conventional two-channel stereo separation.
For Dolby Atmos or DTS:X installations, the final number and position of the ceiling speakers will depend on the room, seating arrangement and supported AV receiver configuration.
Surround Mode Uses One Amplifier Channel
When the switch is set to Surround, connect the speaker cable to either the left or right terminal set.
Do not connect two independent amplifier channels while the speaker is configured for Surround operation.
Multi-Room Audio
The CCM664SR is well suited to multi-room systems where each room or zone needs discreet audio without visible speaker cabinets.
Using one dual-channel speaker in a compact zone can reduce the number of ceiling apertures while preserving information from both channels of a stereo source.
The amplifier, zoning arrangement and cable routes should be established before installation begins.
Ceiling Cut-Out and Mounting Depth
Each CCM664SR requires a circular ceiling aperture measuring 202mm in diameter.
A minimum depth of 133mm is required behind the finished ceiling surface.
Additional clearance should be allowed for speaker cable, the terminal connections, insulation and movement of the QuickDogs mounting clamps.
Check the Ceiling Cavity
The proposed installation position should be checked before the full ceiling aperture is cut.
Look for:
- Ceiling joists
- Electrical cables
- Water and heating pipes
- Ventilation ducts
- Lighting fittings
- Insulation materials
- Fire barriers
- Restricted areas within the ceiling cavity
A suitable detector or small inspection opening may be required before the complete aperture is made.
QuickDogs Mounting System
The CCM664SR uses Bowers & Wilkins’ QuickDogs spring-clamp mounting system.
The clamps rotate behind the ceiling surface and secure the mounting frame without visible external fixings.
The ceiling material must be sufficiently strong and stable to support the speaker. Loose, damaged or unsuitable surfaces may require reinforcement.
Do Not Overtighten the Clamps
The QuickDogs should be secured evenly and only until the frame is held firmly against the ceiling.
Excessive force could damage the ceiling material, distort the mounting frame or make future removal more difficult.
Plug-and-Play Speaker Baffle
The CCM664SR uses a separate mounting frame and removable speaker baffle.
The speaker cable connects to the spring terminals on the frame, allowing the wiring and frame to be installed before the complete speaker assembly is fitted.
The baffle then makes its electrical connection when it is placed into the mounting frame.
Stereo-Mode Speaker Cable
Single-speaker stereo requires separate connections from the amplifier’s left and right channels.
This normally means using four-core speaker cable or two separate two-core cable runs between the amplifier and speaker position.
The left and right positive and negative connections must be kept separate and connected to the correctly labelled terminal sets.
Surround-Mode Speaker Cable
Surround mode requires one two-core speaker cable from the relevant AV receiver or amplifier channel.
The cable can be connected to either the left or right terminal set, provided the switch on the speaker is set to Surround.
Correct polarity should be maintained, with the amplifier’s positive terminal connected to red and its negative terminal connected to black.
Use Low-Resistance Installation Cable
Good-quality, low-resistance speaker cable is recommended, particularly where the cable route exceeds five metres.
Leave enough spare cable at the aperture to simplify connection and future servicing, but avoid excessive loose cable that could create buzzing or rattling.
Amplifier Matching
Bowers & Wilkins recommends amplifier power between 25 and 80 watts per channel.
In Stereo mode, each channel has a nominal impedance of 8 ohms and a minimum impedance of 4 ohms.
Sensitivity is rated at 82dB for one channel and 88dB when both channels are driven.
The correct amplifier will depend on the room, required volume, listening distance, cable length and whether the speaker is being used in Stereo or Surround mode.
Optional Pre-Mount Kit and Back Box
The optional C6 pre-mount kit can be used during new construction or refurbishment to establish the speaker position before the finished ceiling is installed.
The optional 6C back box provides a dedicated enclosure behind the speaker and may help with sound transfer, fire-barrier requirements and performance consistency.
Both accessories are sold separately and should be specified before building or ceiling work begins.
Installation Considerations
Before work begins, consider:
- Whether the speaker will operate in Stereo or Surround mode
- The main listening position
- The required home cinema or multi-room layout
- The 202mm ceiling cut-out
- The 133mm minimum mounting depth
- Ceiling joist positions
- Speaker cable type and number of conductors
- Amplifier channels and impedance loading
- Sound transfer into adjoining rooms
- Access for future servicing
- Whether a pre-mount kit or back box is required
- Relevant building and fire-safety requirements
Where there is any uncertainty, installation should be completed by a suitably competent professional.
Finish
The CCM664SR is supplied in white with a circular low-profile grille.
The grille and visible frame can be painted to coordinate with the surrounding ceiling, provided the grille perforations remain clear.
The speaker baffle and drive units should be removed or protected before any painting is carried out.
Key Features
- Performance Series dual-channel in-ceiling speaker
- Supplied individually
- Single-speaker stereo operation
- Conventional surround-channel operation
- Two-position Stereo and Surround switch
- Two offset 20mm soft-dome tweeters
- 150mm woven glass-fibre bass and midrange driver
- Twin bass and midrange voice coils
- QuickDogs spring-clamp mounting system
- Plug-and-play removable speaker baffle
- 48Hz–30kHz published frequency range
- 82dB sensitivity per channel
- 88dB sensitivity with both channels driven
- 8-ohm nominal impedance per channel
- 4-ohm minimum impedance per channel
- 25–80-watt amplifier recommendation per channel
- 240mm frame diameter
- 202mm ceiling cut-out
- 133mm minimum installation depth
- 4mm protrusion from the finished surface
- Optional C6 pre-mount kit
- Optional 6C back box
- Five-year limited manufacturer’s warranty
Frequently Asked Questions
Is the Bowers & Wilkins CCM664SR sold individually?
Yes. The CCM664SR is supplied and priced as one dual-channel in-ceiling speaker.
Can one CCM664SR reproduce stereo sound?
Yes. Its two tweeters and twin-voice-coil bass and midrange driver allow one speaker to reproduce both the left and right channels.
Does single-speaker stereo sound the same as two separate speakers?
No. It preserves information from both stereo channels, but it cannot create the same physical left-to-right separation as two speakers installed apart from one another.
What is the Stereo and Surround switch for?
Stereo mode allows one speaker to reproduce two channels. Surround mode configures it to operate as one channel within a home cinema system.
How many amplifier channels are required in Stereo mode?
Two amplifier channels are required: one for the left input and one for the right input.
How many amplifier channels are required in Surround mode?
One amplifier or AV receiver channel is required when the CCM664SR is set to Surround mode.
Can the CCM664SR be used for Dolby Atmos?
Yes. It can be configured in Surround mode and used as an overhead channel within a compatible Dolby Atmos or DTS:X system.
What cable is required for Stereo mode?
Four-core speaker cable or two separate two-core cable runs are normally required to carry the independent left and right channels.
What cable is required for Surround mode?
One conventional two-core speaker cable is required from the relevant amplifier or AV receiver channel.
What size ceiling hole is required?
The CCM664SR requires a circular cut-out measuring 202mm in diameter.
How much ceiling depth is required?
A minimum clear depth of 133mm is required behind the finished ceiling surface.
How large is the visible frame?
The complete circular frame measures 240mm in diameter.
How far does the speaker protrude?
The installed speaker protrudes approximately 4mm from the finished ceiling surface.
How is the speaker secured?
It uses Bowers & Wilkins’ QuickDogs spring clamps to secure the frame behind the ceiling surface.
Can the grille be painted?
Yes. The white grille and visible frame can be painted, provided the grille perforations remain clear and the speaker components are protected.
What amplifier power is recommended?
Bowers & Wilkins recommends amplifier power between 25 and 80 watts per channel.
What is the C6 pre-mount kit?
It is an optional accessory used to establish the speaker position during new construction before the finished ceiling is installed.
What is the 6C back box?
It is an optional enclosure designed for compatible 6-inch Bowers & Wilkins in-ceiling speakers.
What warranty is included?
Bowers & Wilkins provides a five-year limited warranty for passive loudspeakers, subject to its warranty terms and conditions.
Related Bowers & Wilkins Products and Audio T Guides
Why Buy From Audio T?
- Bowers & Wilkins custom-installation advice
- Single-speaker stereo system planning
- Surround and overhead speaker guidance
- Amplifier and AV receiver matching
- Speaker cable and cable-routing advice
- Guidance on cut-outs, clearances and accessories
- Pre-mount kit and back-box advice
- Installation and setup support, subject to location
- Ongoing after-sales support
Contact your local Audio T store to discuss a Bowers & Wilkins CCM664SR installation.