KEF Ci3160RLM-THX In-Wall Speaker Review

[kyuu]

Hi all — quick install question for KEF Ci3160RLM THX (LCR).
My room has concrete walls, and I’m building a false drywall wall in front of the concrete specifically to mount the speakers, so I can design the rear volume (I know KEF mentions ~60 L ideal and ~30 L minimum; many people just drop them into drywall).
For a concrete-backed false wall, what’s the better approach for this model?

1. Open “infinite baffle” style cavity (but heavily damped/insulated), vs
2. Dedicated MDF back boxes ~60 L per speaker (sealed + lined), to control midbass and avoid L/C/R cross-talk.

I don't think you have to do either 1 or 2. If you build the false wall with studs, the stud bays will effectively separate the speakers just like in an actual drywall-on-studs wall. Of course it's up to you how much effort you want to put in: there's nothing wrong with building MDF back boxes of the appropriate size. It's not necessary, though, in my opinion. Drywall and studs on their own work well, though it wouldn't hurt to at least put in the effort to provide some damping in the form of insulation (I recommend denim-based) and some sort of mass-loaded vinyl applied to the inside. Or if you really want to go all out, do a double-layer of drywall with green glue between the layers (making sure you don't exceed the maximum thickness the speaker's mounting solution can accept).

Also: would it be acceptable to mount them into a wooden TV cabinet / built-in media wall (MDF construction) if I can give each speaker the correct internal volume and proper bracing/damping — or are there cabinet-specific pitfalls (panel resonance, leaks, vibration) that make this a bad idea?

Nothing wrong with this either, if you're planning on doing some bracing/damping inside the cavity so you don't get bad resonances. Though the cabinetry only really needs to be less resonant than your average drywall for that.

 

[Dbassist]

Hi all — quick install question for KEF Ci3160RLM THX (LCR).
My room has concrete walls, and I’m building a false drywall wall in front of the concrete specifically to mount the speakers, so I can design the rear volume (I know KEF mentions ~60 L ideal and ~30 L minimum; many people just drop them into drywall).
For a concrete-backed false wall, what’s the better approach for this model?

1. Open “infinite baffle” style cavity (but heavily damped/insulated), vs
2. Dedicated MDF back boxes ~60 L per speaker (sealed + lined), to control midbass and avoid L/C/R cross-talk.

Also: would it be acceptable to mount them into a wooden TV cabinet / built-in media wall (MDF construction) if I can give each speaker the correct internal volume and proper bracing/damping — or are there cabinet-specific pitfalls (panel resonance, leaks, vibration) that make this a bad idea?


View attachment 509903

As stated by another user, the stud bays effectively become boxes, and with most of the KEF CI speakers being less than 4" deep, it seems like they were designed to be easily retrofitted.

Now you have all the freedom in the world, so you could, for example, build boxes with constrained layer construction (two layers of MDF with green glue in-between), or you could line the box with rock wool (although for acoustic volume, measure as if the rock wool was part of the box walls). For damping, KEF recommend half filling from the back with the standard pink fiberglass stuff from Lowes. If you take a floor to ceiling length, you can tear it in half front to back (remove the paper backing too), and you have enough for two floor to ceiling bays.

Edited to remove accidental quoting.

 

[Timcognito]

Use construction adhesive wall studs and concrete and drilled in concrete anchors on the on the two studs on each side of of the speaker bays. Use 5/8" drywall with extra screws 6" spacing.

 

[Dj7675]

Hi all — quick install question for KEF Ci3160RLM THX (LCR).
My room has concrete walls, and I’m building a false drywall wall in front of the concrete specifically to mount the speakers, so I can design the rear volume (I know KEF mentions ~60 L ideal and ~30 L minimum; many people just drop them into drywall).
For a concrete-backed false wall, what’s the better approach for this model?

1. Open “infinite baffle” style cavity (but heavily damped/insulated), vs
2. Dedicated MDF back boxes ~60 L per speaker (sealed + lined), to control midbass and avoid L/C/R cross-talk.

Also: would it be acceptable to mount them into a wooden TV cabinet / built-in media wall (MDF construction) if I can give each speaker the correct internal volume and proper bracing/damping — or are there cabinet-specific pitfalls (panel resonance, leaks, vibration) that make this a bad idea?


View attachment 509903

Not sure if helpful or not… but I just went through this as noted earlier in this thread that showed a mock up. Our TV (microled) was mounted on a heavy duty mount so it stuck out 9-10 inches. As a result we couldn’t put the speakers in wall as originally planned. So we built a structure so the speakers wouldn’t be blocked by the TV. So it is a false wall of sort. The advantage is you basically get total control of speaker volume, You basically are making speaker cabinets of sorts. Basic structure was 2x10’s, made sure each compartment was sealed. Due to the room, and large display, we chose to toe in the left/right 15 degrees as well as angle the top center down and bottom center up. Columns ended up being similiar…. Angled and sealed speaker cabinets basically as well. I obviously can’t compare to if I did inwall vs building seperate boxes, but I do think it sounds great, but with a little care I bet it would also sound great directly in wall.

View attachment 510058

 

[drhouse93]

Thanks everyone, didnt expect such a wide amount of responses. I heard back from KEF Support and wanted to add the manufacturer guidance for the Ci3160RLM-THX (and Ci160QR). It lines up closely with what was said here:

Thank you for contacting KEF Support. I've answered your questions in turn below and there is a lot of information, so if you need clarification, please call me

Mounting the Ci3160RLM-THX:
The material you build an enclosure from won't matter as long as the speakers do not share the same stud bay. An enclosure is not necessary, but if you do build an enclosure for them, seal the box with silicone to avoid air escaping through the gaps.

Recommended cabinet volume:
I've attached a chart with the recommended cabinet volume for all the Ci Speakers we currently sell/make. The Ci3160RLM-THX has a ideal cabinet volume of about 60 Liters.

Insulation?
For all applications, our recommendation is to use Blown in Fiberglass insulation. Anything else will be too dense, and can compromise the speakers performance.

Installation:
When installing any of the Ci speakers within a stud bay or soffit, it is best to leave them open. Exceeding the minimum cabinet volume we list does not hurt, it is always better.

Bracing?
It is not a bad idea to add bracing between the studs above and below the speakers to add support. If you're building from scratch, adding rough in frames, and using thicker drywall will also help support the speakers. Using additional drywall screws and adding a construction adhesive between the studs and the drywall per the manual is also a good idea.

Back Box on Ci160QR:
The same applies to the Ci160QR as the Ci3160RLM-THX. The Ci160QR has an ideal cabinet volume of 25.5 Liters. As long as it meets or exceeds that, then it is fine without the back box. Again, blown in fiber glass insulation is our recommendation. All of our architectural speakers have plastic cans to protect the drivers, so it is unnecessary to provide additional protection.

 

[kyuu]

Yup, all good advice, can't argue with Kef except for one thing. They didn't mention treating the inside of the walls, which I think is a relatively cheap and easy win. I used Sonic Barrier Acousta Blue+ for my install.