• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

RSL C34E MKII In-Ceiling Speaker Review

Rate this speaker:

  • 1. Poor (headless panther)

    Votes: 9 7.4%
  • 2. Not terrible (postman panther)

    Votes: 39 32.0%
  • 3. Fine (happy panther)

    Votes: 62 50.8%
  • 4. Great (golfing panther)

    Votes: 12 9.8%

  • Total voters
    122

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,201
Likes
232,095
Location
Seattle Area
This is a review and detailed measurements of the RSL C34E MKII architectural, home theater speaker. I purchased it for testing and costs US $149.
RSL C34E MKII in-ceiling in-wall home theater surround speaker architectural review.jpg

Please excuse the stock picture. Speaker is still on an ugly baffle on Klippel NFS. As this type of speaker goes, the C34E MKII is lighter than others I have tested. Instead of one large and heavy woofer, two smaller mid-woofers are deployed at an angle. I was not a fan of the rotating tabs in the back as they did not extend past the edge of the rim. This means if you cut your hole a bit too big, they won't bite. There is a diagram that I think shows you can rotate them but I did not mess with that.

Measurements are performed without the grill using the "baffle" mode of Klippel NFS where the system computationally eliminates the back wave and diffraction from edge of my mounting board. The result is anechoic measurements as if the speaker was mounted on an infinite wall. I measured the C34E at 90 degree out relative to mounting surface. In that regard the drivers are pointing down. I left the high frequency attenuation switch at 0 dB.

RSL CE34E MKII Speaker Measurement
Let's start with our anechoic frequency response measurements:
RSL C34E MKII in-ceiling in-wall home theater surround speaker anechoic frequency response mea...png

I must stay I expected a messy response given the multiple mid-woofers but this is actually pretty good! On-axis response is nearly flat to 4 kHz. Above that there is a zig-zag response but we have seen much worse. Directivity however suffers due to multiple drivers interfering with each other at higher frequencies (above 2 kHz). So response will be somewhat room dependent.

Our model of early reflections and predicted response are for stand-alone speakers away from the wall. So they don't apply here but their averaging function is useful and points to a rather smooth response:
RSL C34E MKII in-ceiling in-wall home theater surround speaker anechoic frequency response mea...png

RSL C34E MKII in-ceiling in-wall home theater surround speaker architectural predicted in-room...png


How you angle these speakers if mounted in the ceiling is important. Horizontally you have a sort of an "MTM" configuration so best point the speaker at best seat:
RSL C34E MKII in-ceiling in-wall home theater surround speaker horizontal frequency response m...png


Otherwise you get that trough between 1 and 2 kHz.

"Vertical" response in the case of ceiling mounting means moving from being right under the speaker to further out:

RSL C34E MKII in-ceiling in-wall home theater surround speaker anechoic vertical frequency res...png


Surprisingly the best response seems to be right under the speaker. If you go past ± 10 degrees, response gets quite messy. So seems off-axis response of these drivers is more optimal than their on axis!

As I noted, directivity is quite poor and you can see it in all of our plots:
RSL C34E MKII in-ceiling in-wall home theater surround speaker beamwidth horizontal measurement.png

RSL C34E MKII in-ceiling in-wall home theater surround speaker horizontal directivity measurem...png


RSL C34E MKII in-ceiling in-wall home theater surround speaker vertical directivity measurement.png

See how messy the vertical directivity is. The only clear path through it is the on-axis at 0 degrees.

Power handling was very good at 86 dBSPL but at 96, or even before it, it started to make all kinds of intermodulation noises during frequency sweeps:
RSL C34E MKII in-ceiling in-wall home theater surround speaker relative distorton measurement.png

RSL C34E MKII in-ceiling in-wall home theater surround speaker THD distorton measurement.png


Those sharp resonances may be accentuated in the way I have it mounted in my baffle. Then again, you may suffer the same or worse when you mount it on your surface.

Impedance is relative high which should make it an easier load to drive for the amplifier:
RSL C34E MKII in-ceiling in-wall home theater surround speaker impedance and phase measurement.png


Finally, here is our waterfall and step responses:
RSL C34E MKII in-ceiling in-wall home theater surround speaker CSD waterfall measurement.png

RSL C34E MKII in-ceiling in-wall home theater surround speaker step response measurement.png


Conclusions
In this class of speakers, we are used to uneven responses. In that context, the C34E MKII performs pretty well. For most of the important range in frequency response, it produces a neutral sound. Directivity is poor and is to be expected based on multiple drivers. Fixing these with EQ may be hard and require fair amount of experimentation. Power handling is good enough but will not be suitable to high SPL situation. Now take into account the $149 price and you have a killer offering! Hard to imagine all of these parts and this level of performance for so little money. Company really knows what it is doing on this front.

I don't provide recommendation for speakers I have not listened to but if I were to do so based on the data alone, I would put it on my list.

Manufacturer SPECIFICATIONS:​

C34E MKII In-Ceiling Speaker
  • Woofer(s): Dual 4 1/2” woofers with high-energy ferrite magnets, woven aramid fiber cones, butyl-rubber surrounds, and high-strength cold-rolled stamped steel frames
  • Tweeter: 22mm treated-fabric exposed dome swivel tweeter with neodymium magnet
  • Frequency Response: 65Hz – 20,000 Hz
  • Nominal Impedance: 8 ohms
  • Sensitivity: 89dB SPL (1W/1M)
  • Recommended Amplifier Power: 25 – 150 watts
  • Crossover Frequency: 2,800 Hz
  • Crossover Slope: Asymmetrical 12/6dB per octave
  • Crossover components: Proprietary, low insertion-loss lami-core and air-core inductors, RSL poly capacitors, non-inductive resistors, gold-plated spring-loaded binding posts, FR-2 PCB
  • Tuning Method: Infinite baffle
  • System Resonance: Application dependent
  • Weight: 4.25 lbs.
  • Dimensions (overall): Diameter: 11 5/8”, Depth: 3 3/4”
  • Hole: Cut-out Diameter: 10 1/8″, Mounting Depth: 3 1/2”

-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Last edited by a moderator:

lc6

Active Member
Joined
Jul 19, 2022
Messages
181
Likes
275
I do not get the idea of all those in-wall speakers. Basically, you are supposed to mount them on the drywall, but you have no control over what is behind them (joists or trusses for the floor or attic above, or studs for sidewalls, with insulation of some type, wires, plumbing, vents, etc.). This is an acoustically variable and uncontrollable environment, so the actual results vary widely. Even when mounted on a plain wood "baffle" (quite different from the typical 1/2" GWB) for idealized "normalized" measurement purposes, the frequency response is usually quite lousy and the effective directivity rather narrow. Supposedly, the benefit is cost reduction since no enclosure is needed. Would it not be better to instead use full enclosure-based speakers by cutting a rectangular opening for the grille flush with or slightly projecting from the ceiling or wall?
 

Timcognito

Major Contributor
Forum Donor
Joined
Jun 28, 2021
Messages
3,142
Likes
11,882
Location
NorCal

Michael Fidler

Active Member
Audio Company
Joined
Dec 11, 2021
Messages
117
Likes
517
Location
Kent UK
Pretty good for the price - definitely better value than the last one tested!

Voted FINE, but it would be very interesting to see a ceiling speaker with wider dispersion at HF. This one looked promising but double drivers are sure to cause lobing at some point. I guess you have to make different decisions with the design for ceiling speakers in terms of crossover points to minimise this...
 

AdamG

Follow the Science, no matter where it may lead.
Moderator
Forum Donor
Joined
Jan 3, 2021
Messages
4,567
Likes
14,666
Location
Reality
In the Celing Mounted Catagory. This is as close to the Golfing Panther that I think we have seen. For the price this is really good performance. Thanks for the back to back Ceiling Speaker Reviews. Revel is not doing well in this comparison. You come to expect more from them and the only more they gave us is more expensive.
 

Hart

Active Member
Joined
Jan 18, 2021
Messages
147
Likes
331
Location
Bay area
I do not get the idea of all those in-wall speakers. Basically, you are supposed to mount them on the drywall, but you have no control over what is behind them (joists or trusses for the floor or attic above, or studs for sidewalls, with insulation of some type, wires, plumbing, vents, etc.). This is an acoustically variable and uncontrollable environment, so the actual results vary widely. Even when mounted on a plain wood "baffle" (quite different from the typical 1/2" GWB) for idealized "normalized" measurement purposes, the frequency response is usually quite lousy and the effective directivity rather narrow. Supposedly, the benefit is cost reduction since no enclosure is needed. Would it not be better to instead use full enclosure-based speakers by cutting a rectangular opening for the grille flush with or slightly projecting from the ceiling or wall?
I think the goals of home theater are more effect based than a purely two channel system that is high-fidelity based. Of course the goal is always the best reproduction possible however compromises are going to have to be made to create an Atmos system for instance. It would pretty difficult to fasten a good box speaker on to the ceiling. There are some things you can do: block out the joist space to the ideal amount of cubic inches, caulk all the seams/cracks, etc.. In the end I think most of the information will come from the three front speakers that are "high-fidelity" and the other speakers contribute enough to create the effects. I am not sure during a movie you would notice the same things you would in a two channel system from an imperfect surround speaker.
 
Last edited:

Dj7675

Major Contributor
Forum Donor
Joined
Jan 12, 2019
Messages
2,099
Likes
2,767
Great to see this one reviewed as one of the most popular and recommended speakers for Atmos. For $149 it is quite an amazing IMO. Also it is good to see the actual performance to see if it is worthy of so many recommendations (it seems quite fine for the application for most). In particular not a good option at high SPL’s (will be quite fine for many). These ceiling speakers are a pain to test. Much appreciated!
 

ExUnoPlura

Member
Joined
Jul 23, 2020
Messages
46
Likes
121
Location
Oregon Coast
I just built out a 7.2.4 home theater using comparably-priced OSD Black Series R83DT. I used salvaged wood from a demolition project and compensated for beamed ceiling via spanning planks (angled at rear):
ceiling1.jpeg

The L/R surrounds are Revels but these seemed adequate for the heights. The critical step is Dirac live for tuning the system. Here's how that worked out for this one:
dirac-rhr.jpg

Dotted pink is tuned response. I can't say I hear the dropout from 50-70 Hz! :)
 

Hart

Active Member
Joined
Jan 18, 2021
Messages
147
Likes
331
Location
Bay area
I just built out a 7.2.4 home theater using comparably-priced OSD Black Series R83DT. I used salvaged wood from a demolition project and compensated for beamed ceiling via spanning planks (angled at rear):
View attachment 314269
The L/R surrounds are Revels but these seemed adequate for the heights. The critical step is Dirac live for tuning the system. Here's how that worked out for this one:
View attachment 314270
Dotted pink is tuned response. I can't say I hear the dropout from 50-70 Hz! :)
Are the back of the speakers contained in a box?
 

ExUnoPlura

Member
Joined
Jul 23, 2020
Messages
46
Likes
121
Location
Oregon Coast
Are the back of the speakers contained in a box?
No, they are mounted through the plank and open to the ceiling.
 

ROOSKIE

Major Contributor
Joined
Feb 27, 2020
Messages
1,900
Likes
3,357
Location
Minneapolis
I do not get the idea of all those in-wall speakers. Basically, you are supposed to mount them on the drywall, but you have no control over what is behind them (joists or trusses for the floor or attic above, or studs for sidewalls, with insulation of some type, wires, plumbing, vents, etc.). This is an acoustically variable and uncontrollable environment, so the actual results vary widely. Even when mounted on a plain wood "baffle" (quite different from the typical 1/2" GWB) for idealized "normalized" measurement purposes, the frequency response is usually quite lousy and the effective directivity rather narrow. Supposedly, the benefit is cost reduction since no enclosure is needed. Would it not be better to instead use full enclosure-based speakers by cutting a rectangular opening for the grille flush with or slightly projecting from the ceiling or wall?
It really doesn't matter much what is behind the wall.
The q of the speakers woofers is optimized for a large space(enclosure), that is what matters
Even the fact the wall material is drywall and therefore not very rigid is not a issue. Think of 'decoupled' tweeter designs, except in a typical in wall/ceiling the whole speaker unit is kind of decoupled.

If you do build in an enclosure, you don't want anything to protrude. You will get comb filtering in the midrange.
Might as well just use on wall at that point as in wall benefits are lost.
 
Last edited:

ROOSKIE

Major Contributor
Joined
Feb 27, 2020
Messages
1,900
Likes
3,357
Location
Minneapolis
No, they are mounted through the plank and open to the ceiling.
Dipole I guess.
Likely not exactly optimal.
Plus you are getting comb filtering along with the dipole strangeness.
Out of curiosity based on your application why did you chose inwalls vs mounting enclosed speakers from a fixture? It seems in your situation in walls are an odd choice.
Dirac can't really fix these issues except on a graph.
 

ExUnoPlura

Member
Joined
Jul 23, 2020
Messages
46
Likes
121
Location
Oregon Coast
Dipole I guess.
Likely not exactly optimal.
Plus you are getting comb filtering along with the dipole strangeness.
Out of curiosity based on your application why did you chose inwalls vs mounting enclosed speakers from a fixture? It seems in your situation in walls are an odd choice.
Enclosed was an option but I wanted to reuse wood, match the circular design of light fixtures over the television, and integrate with the PNW Modern features of the structure. So there were aesthetic choices that figured into the design plan.
 

shuppatsu

Active Member
Joined
Apr 27, 2023
Messages
128
Likes
169
A couple of dumb questions from someone who knows very little about speakers, much less in-ceiling speakers:

What’s the value in having two midrange drivers? I see the downside in that it creates bands where the sound cancels out, so why do it? Is it more efficient, or easier to handle a wider frequency band, or take up less space? Or is it just cheaper?

Would a coaxial speaker be better for casually filling the room with sound, as opposed to a home theater-like situation where people are seated in a known configuration?

I’m tempted to get these. My living room really has no good place for speakers. When we bought the house we had them wire it up for ceiling speakers but I never got around to it, perhaps fearful that they would sound bad.

Which they still might! given the vissicitudes of having no cabinet.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,201
Likes
232,095
Location
Seattle Area

lewdish

Active Member
Joined
May 29, 2021
Messages
232
Likes
169
Arguably measures pretty similar to the Revel in ceilings measured recently, but it doesnt seem to have the output before it runs kinda outta steam. For atmos channels its kinda important cause ive mostly seen people complain about atmos effects not being significant or loud enough, but for $150 its a bop~ I imagine if you had smaller rooms or lower ceilings it will be great~
 

alex-z

Addicted to Fun and Learning
Joined
Feb 19, 2021
Messages
893
Likes
1,667
Location
Canada
Would love to see a Polk 70-RT ceiling speaker tested. They are a 3 way with 7" woofer, 2.5" mid, and .75" tweeter, sells for $140 refurb or $200 new.
 
Top Bottom