The CSS FR-125S is a 4.5 inch full range driver created by Creative Sound Solutions and Adire Audio. The FR-125S uses Adire’s XBL^2 technology and has a large 6mm x-max; very large for a driver under 6 inches. This driver has already received many positive reviews on the Internet. I also give it a positive, although qualified, review; as I expected I would. Adire-designed speakers with XBL^2 are known for their flat frequency response and low distortion levels. At $70 per speaker, the FR-125S is a relatively inexpensive and simple solution for a beginning DIY speaker builder. For about $200, after materials (including some nice Exodus long binding posts), one can build a quality finished bookshelf.
Given the interesting technology at play in these little woofers, I had a variety of questions I sought to answer: What role can this little speaker play? Will it work as a speaker for 2-channel audio? Does it excel at playing certain kinds of music? I was especially interested in comparing the CSS FR-125S to the Exodus Audio Kit 61.
The CabinetI bought the introductory special from Creative Sound that included a pair of speakers, CNC cut front baffles, and matching magnet-embedded grills. The front baffle is 6.5 inches by 11 inches. I used a design for this baffle that can be found here:
http://homepage.mac.com/tlinespeakers/FAL/box-plans/FR125S-7L-vented-box.gifAs you can see, the box is a small ported design. The only modification to the design that I made was to move the port to the front baffle. (See pictures at the bottom).
The speaker was finished with a semi-gloss black latex and a satin polyurethane clear-coat. I used the excellent Exodus Audio Long Binding Posts. (see my review of these posts here:
http://www.diycable.com/main/product_reviews_info.php?products_id=543&reviews_id=26)
I have to say, it was really refreshing to build a very simple little speaker. Other than the finish, it was only a one day project. Incidentally, I don’t think I’ll ever try a semi-gloss black finish again; it shows flaws so easily.
The Initial ImpressionI’ll spare you the long and drawn out story regarding the fact that they didn’t sound very good at first, but quickly burned in and sounded MUCH better. I only mention it to warn other buyers not to panic; the first few minutes weren't pretty.
The SoundRather than break this part of the review up into the different CDs that I’ve listened to on the FR-125S, I decided to break this up by frequency response and other sonic characteristics. The top end is as good a place to start as any. I tried to listen to a variety of music on these speakers.
The Highs – Grade B-/CWhat can I say about the highs? They’re definitely there, which is no small accomplishment for a speaker without a dedicated tweeter. They’d be more than adequate for casual low level listening or to serve as home theater surrounds in a small setup. That’s about all I can say about the highs though. Compared to the Usher tweeter of the Exodus Kit 61, they seemed to have less life, speed, and air. More importantly, however, the Usher tweeter of the Kit 61 has the ability to make the speakers “disappear” and create a nice wide natural image and stage. The FR-125S, to my ears, does not have much of this capability.
The Midrange – Grade A-/B+This is the region where these speakers excel. If you like female vocals and violin music, you’re in for a treat with these speakers. The FR-125S can really sing with these types of music and the speaker had the ability to move me during some of Hillary Hahn’s solo violin passages. During solo passages and other simple passages where the midrange, especially the upper midrange, was the primary part of the music, the FR-125S -might- be a little better than the Kit 61. I can only imagine that this might have to do with the paper cone of the FR-125S and the fact that there isn’t a crossover point in this region. So, what’s the reason for the A-/B+? When the going got rough, (i.e., during a busy passage with a lot of midbass and bass), the midrange loses some of its special qualities and sounds less natural and full and more dry. This would especially happen with male vocals on bass-heavy jazz tracks. Higher female vocals and strings usually stayed largely consistent.
The Midbass – B-The midbass on these speakers is much more full and rich than on other low priced and small bookshelves like the Polk Rti4 (
http://www.polkaudio.com/homeaudio/products/individual/bookshelf/rti4/). This aspect moves the midbass out of the grade C range for me, but that’s all I can say. The Kit 61 midbass, using the Adire Extremis driver, beats the FR-125S in every way imaginable.
The Bass – B-Here again, these little speakers have absolutely amazing bass, given the size and price. For the price, simplicity and size you simply can’t find an equal to the FR-125S. Is it adequate for 2-channel listening? Maybe. However, I do still feel like I’m missing some important portion of the frequency range when listening to the FR-125. For example, there are multiple passages on the Camiel – Sunset disc that have some deep bass lines combined with some good fast and deep drumbeats. The bass lines were usually audible because of the higher frequency portions of the notes, but much of the richness and full sound was lost. Some of the deep and fast drumbeats were simply not audible or achieved an undesirable one-note-wonder character. A subwoofer would be needed for HT and stereo listening in moderate to large sized rooms.
Is the FR-125S adequate for my 2-channel listening? No. I simply know what I’m missing after having listened to my collection on the Kit 61s. Would it be o.k. for some others? Probably. As I mentioned earlier, these speakers really sing playing female vocals and strings on midbass/bass light tracks. How does the simple FR-125S compare to the Kit 61? The Exodus Kit 61 beats the FR-125S in every way I’ve mentioned, and then some. The only place where a person judging the two could have a question is in the midrange.
SummaryFor every variable other than the midrange, I feel like praise of a speaker built solely around the FR-125S needs to be qualified with “given the size, price, and simplicity.”
But you knew this already. People aren’t going to be replacing expensive large bookshelves and towers with speakers built using only the FR-125S. I see this speaker as an excellent role-player. The roles it could do a great job playing:
+ As a satellite in an HT or stereo sat/sub system. This little thing has excellent WAF and would probably do really well crossed over at 80hz.
+ As a small room stereo bookshelf for casual listening, a second system, or for anyone that doesn’t really value sparkling highs and tight accurate lows.
These speakers do make an excellent DIY project. For $200 finished you can build a capable little speaker that sounds MUCH more expensive than it is. I plan to use my pair as computer speakers, supplemented by a spare 10” subwoofer. I think they’ll really excel in this application.
Final NoteI’ve said some critical things about the FR-125S. Please note that my criticism is based primarily on a realistic comparison between a bookshelf based on them and the Exodus Kit 61. Compared to any small commercial bookshelf in the same price ballpark, even speakers twice as expensive, I’d put my money on the FR-125S-based speaker. For a frame of reference, to my ears they easily beat in every way the well-reviewed Polk RTi4. (see
http://stereophile.com/standloudspeakers/1004polk/)
I took these pictures on top of the Kit 61 so you could see the scale and the primary speakers I compared the FR-125S bookshelves to.
Here's another:
