Polk Audio 255c-RT Speaker Review
We are testing and rating the Polk Audio 255c-RT in-wall speaker in today's review. It will be our second in-wall unit we have tested this month and is still a product category fairly new to us. We will do our usual installation in the test studio and share our opinions, criticisms, and advice to help you make an informed choice before buying.
The Concept
As I mention above, we are admittedly new to testing wall speakers. As you can see here, we have a lot of experience evaluating ceiling speakers, but we are still learning the benefits and drawbacks of this speaker design. Obviously, we will compare them to both ceiling speakers and some sets of standard bookshelf speakers so you can wrap your head around what level they perform at.
The Polk Audio 255c-RT is part of Polk’s so-called vanishing range of speakers. They are designed to be minimally invasive and slip easily and undetected into any environment you place them in. The mount is flush with your wall and therefore takes up less space than conventional floor standing or bookshelf speakers.
This is part of a system that is meant to be used in home cinema systems. It is a center channel speaker that provides audio fill in between two stereo speakers usually mounted on either side of your screen. While many of these speakers are sold separately, you can buy them in combination with subwoofers, satellites, and tweeters to configure a full surround sound system.
A single unit is quite costly, with an RRP of $199 but bare in mind that this is a center channel speaker, so you only require one of them.
Installation
Installing in-wall speakers is not easy, and I recommend you have the installed by a professional. You will need to have a separate amplifier and a way to connect your sound to it. There are various options out there, but as you are probably installing them in a home theater or TV setup, I would look at multi-channel devices.
Before you can mount the speakers on the wall, you will need to cut holes in line with the manufacturer’s guidelines and ensure sufficient space for the speaker to mount and ample depth in which the speaker will fit. If you do not have space behind drywall or are trying to install these speakers on solid surfaces like concrete or stone, then I advise you against purchasing this speaker style.
Finally, it is important that you use the correct cable when installing any speaker inside a wall or ceiling. Standard speaker wire will not suffice because the insulated cable needs to be used to meet building regulations and safety codes. As a guide in the United States, you should look for speaker wire with a CL designation.
Specifications
Below you will find the specifications for the Polk Audio 255c-RT speaker directly from the company’s website. After the specs list, you can read our opinions on what these specifications mean.
Orientation: Horizontal
Depth: 3.875" (9.84 cm)
Weight: 6.6 lbs (2.99 kg)
Driver Complement:• (2) 5.25" (13.34 cm) d (Round) Dynamic Balance Mineral Composite Polypropylene Cone with Rubber Surround Mid/Woofer - Mid/Woofer
• (1) 1" (2.54 cm) d (Round) Dynamic Balance Silk Polymer Composite Dome Tweeter - TweeterGrille Dimensions: 9.31" (23.65 cm) h x 14.81" (37.62 cm)
Clearance Required for Mounting Dogs (add to each side of cutout): 3.375" (8.57 cm)
Total Frequency Response: 30 Hz → 27,000 Hz
Nominal Impedance: 8 ohms
Sensitivity (1 watt @ 1 meter): 90 dB
Lower and Upper -3dB Limits: 50 Hz → 25,000 Hz
Speaker Inputs: (1) Pair of Push Connectors - Gold-Plated
Recommended Amplifier Power Per Channel: 10 watts → 150 watts
Our Expert Opinion: Everything here looks fairly normal. The dimensions of the speaker put it on the large side, but that’s forgiven since there are two woofers set inside the housing as opposed to the usual one you see on stereo units. The weight was surprisingly low, and most non-braced drywall should support this without problem
The nominal impedance is only 8 ohms, making them fairly efficient and easy to drive, and provided you have 150 per channel to drive them; you shouldn’t run into problems. Remember that this speaker is considered a channel, and your amplifier needs to be capable of effectively driving all the speakers you connect to in the system.
My only comment is that the depth under 4 inches is a real bonus. Polk has done a fantastic job of keeping the thickness to a minimum; thus, they should be easy enough to install in most homes. As a comparison, we have seen speakers with an installation depth of 9 inches, making them hard to recommend.
Build and Aesthetic impressions
The build quality is really quite nice. I have tested a few Polk speakers this year, and I think they are very well constructed. The 255c are no different, and although they have generously used plastic in the construction, that seems to be a concise choice to bring the overall system weight down.
The front plate acts as a support base and frame for the drivers who sit free and open on the backside. As you would expect, there is no cabinet housing on these speakers.
When installed, the aesthetic is pretty clean, but Polk should not of put their logo on something that is meant to be inconspicuous. It’s a minor grip, but in my eye, the grill would look better without branding.
The grills only come from the factory in white, but they have a paintable finish on them so you can color match the speakers to your room. I advise using whatever paint your walls are covered in for a proper match. Emulsion paint will work fine here but paint the grills whilst they are off the speaker; if you install them while installed, you could end up costing yourself a lot of money.
Sound
Sound isn’t really relevant here as there is no point in evaluating such a speaker on its own. It’s designed to be used as part of a full system, and in that regard, it sounds amazing. Centre channel speakers aren’t there to provide bass, so the two smaller woofers used here are sufficient.
It projects well and directly forward when set up correctly and has a slight lean to a warmer tone but nonetheless has great clarity. I think really this is what you want from it. Something that makes vocals sound clear and natural. If Polk had leaned too far towards accurate and neutral, it could have sounded thin and unnatural.
I tested the 255c-RT with two of Polks 65 RT speakers to get an idea of what it added to the experience. I would switch the center channel on and off to see the effect it had on the presentation, and it’s such a vast difference to the experience. I don’t think I would recommend anyone set up a home theatre without a center channel or soundbar. It just fills in the gaps and makes for a much fuller multi-directional audio experience.
Final Verdict
If you are building a home theatre sound system with other speakers from the Polk Audio RT line, this is a must. It adds a lot to the movie-watching experience, and with these types of setups, I’m not a big fan of mixing and matching speakers from different brands (with the exception of subwoofers). The build quality is good, and the weight has been kept nice and low, and when you consider you can get the full line in a 5.1 setup for less than $1000 USD, it seems like a great deal to us.
Official Website of the Polk Audio 255c-RT: www.polkaudio.com
