If you are a regular reader of PAS, you might recognize the speakers on these pages, or at least, think you do. The insane widebody Impreza of Arthur Chiang sported the predecessors to these drivers, and the car was once heralded as ‘one of the best-sounding cars’ at an SQ event in New Jersey a few years back. Clarion has just released the new Signature Series component speakers, and we have their flagship SSS601 6.5-inch two-way set in the lab to check out.

Features
Clarion Canada’s Manager of Marketing and Product, Brad Wisnoski, explains the story behind the Clarion Signature Series: “Given the performance capabilities of our source units and amplifiers, we chose to develop a line that offers something to equal their finesse. The result is a line of speakers and subwoofers designed for people who appreciate what music is supposed to sound like.”

The Clarion Signature Series includes four products: 10- and 12-inch subwoofers and 6.5- and 5.25-inch component speaker sets. The SSS601 component set Wisnoski sent us includes a pair of 6.5-inch woofers, 1-inch tweeters, passive crossover networks, grills, speaker wire and mounting hardware.

We’ll check out the tweeter first. The tweeter is based around an inverted 1-inch titanium diaphragm. In the center of the tweeter is a waveguide. This waveguide helps to improve off-axis performance. The CCAW voice coil winding is immersed in a bath of Ferrofluid. This magnetically conductive material helps to increase tweeter efficiency as well as transfer heat away from the voice coil winding. Ferrofluid also helps to dampen any potential resonances that might occur, improving the driver’s smoothness. The tweeter offers a pair of gold-plated spade terminals as electrical connections, making it very easy to connect.

The tweeter offers only one mounting solution: flush (more on the reason behind that in a second.) To install, simply drill a 1.58-inch hole, slide the tweeter through and secure from behind with the supplied hardware and bracket. So why only one mounting solution? As we will continue to reveal, the Signature Series was designed to sound good in an every-day installation. Not everyone can afford custom kick panels or door pods, and the product development team at Clarion Canada took this into consideration when designing the product. Both the woofer and tweeter share technologies to offer excellent off-axis performance. These drivers should sound great even when installed in the factory speaker locations.

The woofer is based on a cast-aluminum frame that bears a textured powder-coat finish. At the base of the woofer is a single magnet that measures 4 x 0.75 inches. A chromed top plate and bumped T-yoke help to focus the magnetic field on the CCAW voice coil. The magnet is concealed by a custom-tooled rubber boot. The voice coil former is made from Kapton for thermal stability. A single 3.6-inch linear roll spider provides compliance at the base of the cone, while a synthetic rubber surround controls the outer edge of the cone. The fundamental design feature of all Clarion Signature Series drivers is their cone. Clarion calls this the Composite Cone Design. To balance the need for low mass, high strength and excellent damping characteristics, Clarion has implemented a cone that is a sandwich of glass fibre and PMI (polymethacrylimide) foam. This results in a cone that is low in mass, rigid and well-damped. Some of the best speakers we have had the opportunity to review use this type of cone design, and so far, all have sounded excellent. At the base of the cone is a 0.85-inch tall parabolic phase plug – a continuation of the concept of improving off-axis performance.

Electrical connections are made by a pair of gold-plated and spring-loaded terminals. The terminals have 0.2-inch holes so 12awg cable can be used without any problem. The tinsel leads are woven into the spider to eliminate the possibility of them creating any mechanical noise. Finally, the basket offers 12 mounting holes on its 6.4-inch outside diameter. Mounting depth is 2.75 inches.

Last but not least are the all-important passive crossover networks. Neatly housed in ABS plastic cases that bear a silk-screened Clarion logo, these networks offer three tweeter output level options: 0dB, +3dB and -3dB. Inside the crossover network we find a pair of inductors, one air core, and the other iron. Good quality 100V polyester capacitors help with the filtering duties. Tweeter protection is presented in two forms; a PTC and a set of four zener diodes. Clarion explains that this not only effectively protects the tweeter from being overdriven, but also prevents the amplifier from ‘seeing’ any strange loads. Four wire-wound ceramic resistors are implemented to affect the tweeter output level. Finally, each and every component is firmly secured to the circuit board with a clear adhesive. Absolutely nothing budges a millimeter. Connections are made via a gold-plated terminal strip that will accept 0.4-inch spades. The crossover point is set at 4,000Hz.

Testing
With an impressive offering of technologies, we had our hopes up that these speakers would live up to our lofty expectations. We started testing by breaking in the speakers using a frequency sweep at an adequate level to exercise the driver’s suspension. We then installed the drivers in our test enclosures and connected them to our Arc Audio 2150SE amplifier and Clarion DRZ9255 source unit. We let the system play for a day to further condition the passive network and the tweeter. Once we confirmed all the connections were acoustically correct, only then was it time to sit down for a listen.

But before we get to that, a little more on the nitty gritty behind the speakers. The woofer was subjected to our Woofer Tester 2 to capture some Thiele-Small parameters. FS is 77.1Hz, Vas is 3.25 cubic feet, Qts is 0.6696 and Re is 2.8 Ohms. We also took a sweep of the tweeter. This revealed a resonant frequency that was very well damped in the 1,300Hz region and a similar 2.7-2.8 Ohm resistance. Should you (for some reason) want to connect two pairs of these drivers to a single channel of your amplifier, you will need to make sure it will handle the <2 Ohm load.

But enough of the white papers, calipers and software, it’s what a speaker sounds like that really reveals the story. Listening started with the real challenge – Spanish Harlem by Rebecca Pidgeon. This track is universally agreed upon amongst the PAS testers as one of the toughest challenges for midrange accuracy and detail. So how do the Signature Series speakers perform?

The SSS601 offered completely smooth frequency response, but they had a sound of their own, not the antiseptic sound of some European speakers, but more of an ethereal feel to them – light, open and airy without adding any emphasis in any region. It made Rebecca’s voice stand out front and center from the background instruments.

Given the excellent performance with female vocals, we had some concern for the performance of male vocals. Lacking a collection of Barry White records, we chose Junior Wells’ Sweet Sixteen from the USACi Sound Quality Test CD. This again showed smooth response with an open sound. We moved the tweeter output level down to the -3dB setting to see what effect it had on tonal balance. It took some of the ‘zip’ out of the highs and gave male vocals a much more ‘neutral’ balance. We went back to listen to Rebecca Pidgeon. This was it – this was the home run. Rebecca’s voice was as smooth, detailed and balanced as we have heard in a long time. But would the background shakers and piano be dulled? Not at all. The strings and shaker were perfectly balanced and the piano was clear and sharp on each keystroke.

So what of the other capabilities of the SSS601 set? Can they rock? We cued up AC / DC’s Razor’s Edge and the well-known Thunderstruck track. We warned the neighbours and set things loose. The guitar of Angus Young warns of the impending Drums of Chris Slade. It was then that the dynamic impact of the Signature Series revealed themselves. The drums and bass were clear and loud while allowing the lead guitar and vocals to remain clear – an experience that left a smile on our faces.

To wrap things up, we’ll take a quick set of frequency response measurements. The two lines in Figure 1 represent the woofer (in blue) and the tweeter (in red), both close-mic’ed to eliminate any room reflections. You can see that the response is extremely smooth across the entire frequency spectrum. The cone of the woofer does start to break up above 4,000Hz, but the output quickly decreases thanks to the passive filter. The tweeter comes on quickly at that very point to take over output duties. It shows a small rise in response of 5dB at 16,000Hz which likely contributes to the over-airiness of the system. Off-axis, this would result in very flat response.

Conclusion
There’s nothing we enjoy more than getting the opportunity to listen to a great set of speakers. The Clarion Signature Series certainly falls into that category. What is more impressive than their excellent sonic characteristics is that there was some design effort put into the speakers to make them sound good in a normal car environment that ‘normal’ people would use. You don’t need to spend hundreds, if not thousands, to make them sound good in your car – doing that would only make them sound better.