RBH Sound TK-5C Bookshelf Speaker System Review

Introduction

Over the summer, I rallied up the primary Audioholics staff to come over to my place for a little bookshelf speaker shootout. This was an enlightening experience where we all learned that the old saying “you get what you pay for” did prove itself quite admirably here as we progressively jumped up the loudspeaker price ladder from $200/pair to over $1k/pair, though the differences at the top end of the scale seemed to be more diminutive. Nonetheless, we found two gems in the $400/pair price class; one being the Usher S-520s and the others being the RBH Sound TK-5Cs. I decided to explore these speakers further by engaging them in a formal review using the Ushers as a reference for comparative purposes.

Build Quality

On the surface, there is nothing substantial about the RBHs. I would classify their build quality as average and their appearance as acceptable. They certainly don’t hold a candle to the Ushers when it comes to appearance in my opinion but they don’t stick out like a sore thumb like the HSU bookshelf speakers we previously reviewed either. Beauty is in the eye of the beholder I suppose but I did tend to find the fiberglass cones somewhat sexy and thus preferred how they looked with no grills, naked if you will.

The TK-5Cs are a vinyl wrapped cabinet constructed of MDF with piano glossy tops to add more aesthetic appeal. Standing at only a foot tall, they are rather unobtrusive and are relatively easy to place in a room, though because of their rear ports, I’d advise against placing them directly up against a wall or into a cabinet enclosure without first stuffing the port and bass managing them through your receiver or processor.

Just like with the Ushers, the manufacturer did NOT include a gasket ring around the woofer to minimize cabinet / driver resonance. Quite frankly I don’t understand this omission as it is certainly a useful design tool at virtually no cost added other than a few seconds in labor to place it on the driver.

Editorial Note about the Driver Gasket Ring

In speaking with RBH Sound, they did inform me that in fact these speakers do implement a gasket ring around the woofers and they were unsure why my review samples didn’t have them. It's quite possible since I had the first run of speakers in for review before they went into production that they were inadvertently left off during assembly.  I have included a picture they supplied me of one of their production units that shows the gasket ring. They also explained why they chose to use a smaller sized gasket that doesn’t cover the entire outer diameter of the driver.

With the type of stamped basket the woofer of the TK-5C employees, the surface of the basket is actually raised so that there is no contact with the cabinet except at the area where the gasket is and the very thin outer edge of the basket. According to RBH engineer Shane Rich, since the rim of the basket is raised and does not come in contact at all with the cabinet except at the very thin outer edge a smaller sized gasket ring was employed which purposely doesn’t cover the entire diameter of the outer edge of the basket frame. Since the driver cutout of the cabinet is recessed and due to the thin nature of the outer edge of the basket, a gasket will not pinch between the basket and cabinet, it will simply slip underneath the raised portion of the basket and the thin outer edge of the gasket will bend slightly outwards towards the recess in the cabinet. The smaller gasket employed in this speaker does a good job of effectively sealing the cabinet and damping the basket.

The TK-5Cs utilize a magnetically shielded glass fiber 5 ¼” midbass driver with butyl rubber surrounds and a stamped basket. Having some good personal experience working with fiberglass cones in my days of telecommunication work for the government, I can attest to the fact that this is a very good and cost effective cone material to use and is at least on par with Kevlar at only a fraction of the cost. The tweeter is a 1” silk dome ferrofluid cooled design with a conventional ferrite magnet motor structure. I was relieved to find RBH didn’t skimp here and use a cheap neodymium driver or substandard metal dome, not to say that either driver types can't be good, but the inexpensive ones often tend not to be. The crossover is an electro-acoustical second order design, utilizing air core inductors and polypropylene capacitors instead of lower fidelity electrolytics some manufacturers tend to utilize in series with tweeters as a cost cutting technique at the expense of harshness and graininess in the sound. The cabinet is heavily stuffed with Dacron insulation but has no physical bracing making it sound a bit hollow when rapping on a side wall. There is a pair of gold plated binding posts so no bi-wiring or bi-amping is possible with these speakers.

Set-Up

I placed the TK-5Cs on my 30” sand-filled Plateau speaker stands which puts the tweeter right at about ear level on my Continental theater seats. The speakers were positioned about 5ft from side and back walls and spread apart about 10ft from each other which was roughly the distance from my primary listening position. After experimenting, I found they sounded their best with moderate toe-in, adding more focus and tightening up the soundstage. Be careful not to over toe these speakers as they will sound bright or too hot in the top end. I used the Emotiva Reference Theater Series preamp and processor, the Denon DVD-5910CI as the source and a pair of Usher S-520 speakers I had on hand for direct comparative purposes. All cables were furnished by Impact Acoustics (Sonicwave toslink) and Bluejeans Cable (10AWG speaker cable and analog interconnects).

TK-5C Listening Tests

CD: Fourplay – The Best of Fourplay

What do you get when you combine some of Jazz’s most talented musicians in one band? Bubble gum “radio friendly” jazz for the most part unfortunately. There are moments of excellent musicianship on this CD; a few more meaty non radio friendly songs that seep through the pores of any jazz lover like spicy Mexican food does through a person suffering from IBS. Track #5 “Chant” separates the men from the mice when it comes to determining a loudspeaker's true dynamic capabilities. The kick drum at the opening passage will either radiate beautifully through a loudspeaker's bass drivers, or send their voice coils slapping out of the magnetic gap with a non-orgasmic popping sound. Trust me, it isn’t pleasant, nor is this punishment beneficial to the driver over prolonged exposure. Needless to say, the TK-5Cs handled this passage with much more grace and finesse than the Usher S-520s. The bass was tighter and cleaner on the TK-5Cs while it was more extended on the S-520s. As I cranked the volume up, the TK-5CTs began showing signs of distress, though never bottoming out, while the Ushers were bottoming hard sounding like one of those newspaper poppers I used to construct as a child to torment my bigger brother while he was napping. Basically the RBH’s traded off extension for greater power handling and dynamics. This, in my opinion, is a good trade off when dealing with small speakers as one could always add a subwoofer or two to achieve greater bass extension and impact. This of course is a requirement of home theater and I believe a necessity for all small single woofer speaker systems should you desire to reproduce the full frequency spectrum of your music.

CD: Donald Fagen – Morph the Cat

Morph the Cat is quickly becoming a regular in my test disc arsenal because of its excellent recording quality and the fact that some of the songs have really started to grow on me overtime. Track #8 “Mary Shut the Garden Door” has a lot going on percussion wise that really reveals a speaker's mettle. The TK-5Cs handled this track nicely placing the vocals upfront and center with good depth and detail in the percussions. I did however feel that the S-520s presented a wider soundstage, though somewhat more recessed in the vocals. The Ushers conveyed more smoothness in the top end at times but both speakers provided an equally enjoyable experience, though from a somewhat different perspective. Some of the tracks with embedded female vocals again proved the RBH’s more forward nature. Though they did well with vocals overall, at times they conveyed an almost “cupped” sound, which I suspect was due to a bit of cabinet resonance. This was a phenomenon not as apparently obvious when listening on the Ushers.

SACD: Patricia Barber – Modern Cool

I had to dust the cobwebs off this SACD as it’s been some time since I incorporated it into a review. Track #7 “Company” got my juices flowing. This is one of those songs that you simply have to hear in its entirety, especially the awesome drum solo midway into it. The guitars were very distinct sounding and in your face on the RBH’s while the vocals were a bit more natural and the top end more refined on the Ushers. The RBH’s were clearly outgunning the Ushers in dynamics and dare I say “quickness” in the bass. I was able to pick up more reverb cues from the snare drum hits on the RBH’s. Track #6 “Silent Partner” really gave the tweeters in both speaker pairs a work out. While both systems did commendably well here, I felt the Usher’s took on a more floaty feel with the brush strokes against the cymbals and Patricia’s voice sounding a bit more natural, but the guitars were bolder (in your face) sounding on the RBHs which was very enjoyable.

As I listened to some of the other key tracks it occurred to me that on close mic’ed recordings such as these, the TK-5Cs almost overemphasize the vocals. Though I suspect the thinness in the lower bass was adding to this effect so I tried throwing a subwoofer into the mix and this did seem to smooth out the overall sonic balance.

TK-5C Measurements and Analysis

Impedance / Phase Measurements of the TK-5C

Rating these speakers 8 ohms is a bit conservative in my opinion as they look more like a 10 ohm speaker than 8 ohms as at their lowest impedance dip around 200Hz or so, they are still hovering above 8.5 ohms. They easily maintain +-30deg phase within the entire audio band making them a very easy load for virtually any amplifier to drive.

In Room ½ Meter Frequency Response of the TK-5C (1/12^th octave smoothed)

I did a quick and dirty in room response measurement of the TK-5Cs at ½ meter. What I found was that the -3dB point as confirmed by the frequency response and saddle point on the impedance graph is around 60Hz just as the manufacturer claims. They maintain a linear response of +-3dB throughout the entire audio range but do tend to favor the lower midrange in the 1kHz to 3kHz region just like my listening tests confirmed. Many manufacturers at this price point tend to taper off the midrange response to hide a speaker systems weaknesses since this is a critical region in human hearing that is unforgiving to bad sound. In tradition with all RBH speakers I’ve reviewed in the past, they don’t hide anything. Instead, their speakers bring forth the midrange, which can at times sound a bit analytical, but on good recordings you will be rewarded with great dynamics and realism in the vocals and percussion.

TK-5C Conclusion

It was a pleasure spending more time with the RBH Sound TK-5C and Usher Audio S-520s speakers. I’d like to be able to declare a definitive winner as to which product was better, but to be honest, my original conclusions from our 2007 Bookshelf Face Off review remains the same. Both of these products have their own associated strengths and weaknesses. I often found my preferences between these two speaker systems changed depending on the source material I was listening too and at what volume levels. The RBHs clearly shined in dynamics and boldness, especially with kick drums and lead guitar solos, while the Usher’s shined during delicate acoustical music passages and female vocals while not being taxed to produce slamming bass at high SPL levels.

The RBH Sound TK-5Cs proved to be a top notch performer in the $499/pair bookshelf speaker category. Their ability to sound BIGGER than they looked without faltering at high SPL levels even when not bass managed was most impressive. Make no mistake however that, as most bookshelf speakers, these are not full range and should be mated with a subwoofer to extend the low end frequency response and better balance the entire sonic spectrum. While they didn’t score big points with me in the looks department (the Ushers were the clear winner here), they did so in the category that matters most to me – performance.

It seems RBH Sound has once again produced a solid offering with their new TK series of loudspeakers, from these little but bold bookshelf speakers to their $850/pair TK-5CT wonder towers that have literally turned the budget tower speaker market upside down. One thing is for certain, RBH Sound is serious about winning your business at any price point you are shopping at.

RBH Sound Loudspeakers

http://www.rbhsound.com
382 Marshall Way
Layton, Utah 84041
801-991-1308 phone
801-543-3300 fax

About RBH Sound

RBH Sound is one of the oldest speaker companies in the USA still run and operated by the original founder - Roger Hassing. In 1976 RBH Sound produced its first loudspeaker. RBH soon began to OEM for McIntosh, (back in the days of Gordon Gow), providing cabinets for their speakers. This set the stage for doing a superb job since McIntosh didn’t worry about how to cheapen the product, but to make it better and, at least at the time, lead the class in performance. Later on RBH Sound began producing loudspeakers for a retailer in Los Angeles called Northridge Audio. They didn’t advertise or market these products to avoid a conflict of interest with their other OEM customers (i.e. McIntosh, Parasound, Fosgate, etc). People nonetheless sought them out because of their high performance, which lead to a good success story and response for their products. Over the years RBH Sound was successful at helping other companies in achieving their goals. Based on their strong engineering background and sourcing ability, they took it upon themselves to enter the market under their own banner.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Build Quality
Appearance
Treble Extension
Treble Smoothness
Midrange Accuracy
Bass Extension
Bass Accuracy
Soundstage
Dynamic Range
Performance
Value