KlipsDude Posted July 22, 2005 Share Posted July 22, 2005 Klipsch RF-7 Powerful Speakers for Low Powered Amps By David Bardes - 2003 All Rights Reserved - Vacuum Tube Valley Magazine Many tube enthusiasts reach back to the vintage Klipsch speakers to get the big, dynamic sound they crave. Compared to today's power-hungry speakers, the Heresy, Forte, Chorus and Khorn speakers are an inexpensive sonic salvation. Unlike other speaker manufacturers which have sacrificed high efficiency for small size and cost reduction, Klipsch continues to make efficient speakers that are a great choice for low powered SE and vintage tube amps. Packaged in a contemporary tower design, Klipsch's RF-7 contains all the advantages of their classic speakers and serves them up with extended frequency response, improved resolution, and great imaging that define modern speaker design. The RF-7 is a two-way tower design. A Tractrix horn-loaded, titanium-dome driver supplies the treble, and two 10" aluminum cones supply the lows and mids. The cones have been anodized on both front and back surfaces, which act as damping layers for the otherwise stiff but ring-prone aluminum. These drivers are crossed over at 2200 Hz using a fourth order Linkwitz-Riley type crossover. A relatively steep crossover was used to control sound dispersion and control "ring modes" in the aluminum cones. Two very large ports occupy the rear of the cabinet. These ports are larger than many other speaker manufacturers use, but are appropriate for the woofer configuration (it is easier and cheaper to use smaller diameter ports at the cost of potential port noise). The cabinet uses veneered MDF, veneered on the inside as well as the outside for improved cabinet damping. My samples were veneered in a beautiful cherry finish. Black ash and light maple are the other options. Twin sets of binding posts are provided for biwiring and Monster Cable Zwire is used inside the cabinet. Most importantly, they are efficient enough for really low powered amps. The RF-7s have a clean open sound. The titanium diaphragm provides great treble extension and a clear sound, but the tweeters sound just a bit frosty at first. Once the tweeters break in, the sound opens up to provide a nice image, both wide and deep. I heard real depth and a sense of the large recording venue for Diana Krall's Besame. I could distinguish the distance of the different sections of the London Philharmonic from the microphones as they backed up Diana's singing. Violins and violas were clearly delineated. Diana's voice was natural and I could not find a hint of coloration from the tweeter horn. I thought I had found a weakness in the RF-7s bass performance which I felt was too pronounced and boomy, although the bass extension was impressive. This boominess turned out to be my single ended amp, because when I changed the amp out to David Bernings's Micro ZOTL amp, the bass tightened right up and delved even deeper, even though the Micro ZOTL amp is rated at just 1 watt! I played several discs with deep, strong bass (Down to the Bone, Crystal Method, etc.) and the RF-7s were quite impressive. Ron Carter's acoustic bass was deep and visceral while playing his version of Cubano Chant (When Skies are Gray, Blue Note). Only a very good subwoofer would provide deeper bass. It may prove that some single ended amps may not have the damping power to get the full measure of bass punch from these speakers despite their high efficiency. Compared to my beloved Khorns, the RF-7s had far superior imaging, better bass and treble extension, and I heard details in recordings I hadn't heard through the Khorns. For me this is impressive, as many speakers sound like toys when compared to the Khorns. True, the Khorns still sounded bigger, but this is a warm fuzzy big, and not the focused image that the RF-7s convey. And if anything, the RF-7s could produce a punchier, more dynamic sound than my corner horns. These speakers deserve consideration for low powered tube rigs. Unlike full-range, single cones speaker designs which are the current rage, these speakers have more muscle, way more treble extension, and they "got bass!" It is important to try your amp with these speakers, as my 300B amp was a good match, but the Micro ZOTL amp was an amazing match with the RF-7's. ($2300/pr SRP). Klipsch RF-7 Subjective Evaluation Dynamic Range 4.5 Transparency 4 Frequency Extension 5 Dimensionality 4 Pace and Rhythm 4 Musical Involvement 4.25 The scale is 1 to 5 with a score of 5 being the very best! Overall Rating: 4.25 Manufacturer Specifications Frequency Response: 32Hz-20KHz±3dB Sensitivity: 102dB @ 1watt/1meter Power Handling: 250 watts maximum continuous (1000 watts peak) Nominal Impedance: 8 ohms Dimensions: (H x W x D): Height: 45" (115cm) Width: 11.6" (29.7cm) Depth: 16" (41cm) Weight: 90 lbs. (40.8kg) Klipsch Audio Technologies 3502 Woodview Trace, Suite 200 Indianapolis, IN 46268 (317) 860-8100 Toll Free: (800) 544-1482 Test System Components: Jolida JD 603 CD player with Mullard CV4004 tubes in the analog output section Assemblage SET 300 amp with Valve Art and JJ 300B tubes, Micro ZOTL amp Homebrew fine wire speaker cables using three strands of 30 awg silver-coated copper wire in a kynar jacket TEK LINE PC-12 Signature power cords for both the amp and CD player VSE Super Clear interconnects Quote Link to comment Share on other sites More sharing options...
nicholtl Posted July 22, 2005 Share Posted July 22, 2005 Very interesting. Is this review from an audio publication? Quote Link to comment Share on other sites More sharing options...
crazytubepower Posted July 22, 2005 Share Posted July 22, 2005 Rf-7's over K-horns!!! Come on Quote Link to comment Share on other sites More sharing options...
tibbit Posted July 22, 2005 Share Posted July 22, 2005 Come-On crazytubepower, stop being so negative, if you haven't tried them yourself you don't have grounds, if you did, it's your choice. I myself have my eye on those RF-7's! Quote Link to comment Share on other sites More sharing options...
tibbit Posted July 22, 2005 Share Posted July 22, 2005 It's the Vaccum Tube Valley Issue 19 publication/magazine. Quote Link to comment Share on other sites More sharing options...
crazytubepower Posted July 22, 2005 Share Posted July 22, 2005 The k-horn has the potential to be better...It is just very room dependent and the rf is not. Quote Link to comment Share on other sites More sharing options...
Petrol Posted July 22, 2005 Share Posted July 22, 2005 -------------------------------- crazytubepower posted: The k-horn has the potential to be better...It is just very room dependent and the rf is not. -------------------------------- Well then, with that in mind I'd easily 'prefer' a pair of RF-7's landing on my doorstep . . . (even if I could convince my wife into letting a free pair of Khorns in the house, I don't have the corners, ablity to mod or room for them) Quote Link to comment Share on other sites More sharing options...
sunnysal Posted July 22, 2005 Share Posted July 22, 2005 both are great speakers, I heard both and I have k-horns. to each his own. regards, tony Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 22, 2005 Share Posted July 22, 2005 I scanned the entire article and Deang posted it on this forum can't remember what the thread title was though. Quote Link to comment Share on other sites More sharing options...
KlipsDude Posted July 26, 2005 Author Share Posted July 26, 2005 I'm certain its been a covered here before, just thought I would share. I gots from a member over on the www.hometheaterspot.com forums, that shared it with me's. He has RF-7's and LaScala. He says he uses his RF-7's for music and the LaScala's for home theater. Quote Link to comment Share on other sites More sharing options...
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