When I was putting in my first car audio system in the '80s, my dream system consisted of highly regarded MB Quart separates. While MB Quart is still highly regarded, the company has gone through some serious changes in more recent years-being purchased by Rockford, receivership in September of 2004 and now the purchase by Maxxsonics (think Hifonics, Autotek and Crunch) early this year.
Maxxsonics announced that they would help the company regain its once-revered position and let the German engineers and designers do what they do best. In August of this year they introduced a new line of component sets, the QSC line. The QSC 216 is the 6 1/2" version with an MSRP of $799.
I must be honest-I was skeptical when I heard about the acquisition by Maxxsonics. The two companies just didn't seem like a good fit. Based on the tests I did on the 216 though, I am now a believer. Everything from the packaging to the fit and function of the product is the MB Quart quality I remember from 1984-but with the best materials and engineering from 2005!
The QSC midrange features a dropforged aluminum basket, chosen over a traditional casting to aid in the dissipation of heat from the speaker's solid core neodymium magnet. To further enhance cooling, heat sinks have been added to the perimeter of the magnet structure. The Kurt Muller-designed cones utilized on all QSC models feature the same curvilinear configuration used throughout the MB Quart product line, which delivers an even midbass response while providing superior off-axis performance. MB Quart says a newly developed coating has been applied to dampen the cone in an effort to smooth transition between the midrange and tweeter. Each cone has been mated to a 1.5" voice coil on a vented Kapton former. A UV-resistant butyl rubber surround and linear treated cotton spider complete the suspension. The mounting options are also well thought out with all the options found on a quality 6 1/2" frame, plus an integrated grille that allows quick installations in select European cars.
The standard titanium dome tweeter has been further enhanced using a nylon composite surround that effectively damps the dome, resulting in a very smooth frequency response. The tweeter also uses an aluminum housing much like the one designed for the midrange driver. They claim the housing increases the tweeter's heat saturation point by over 30 percent, resulting in increased power handling and overall long-term reliability. The tweeters also include well-designed flush, surface and angle mounts.
The crossover is attractive, easy to mount and has enough versatility for most installations. It uses high-grade capacitors and inductors where needed and good layout design to prevent crosstalk.
On to the testing...
Parameter Testing
My testing setup has changed dramatically with the addition of the Klippel Distortion Analyzer. I still use the ACO Pacific 1/4" microphone, lab amplifier and IEC baffle, however all of the testing is done through the Klippel now. It is the "be all-end all" analysis tool for the loudspeaker engineer. The Klippel is revolutionizing loudspeaker design in virtually every application. Check it out at www.klippel.de.
My testing starts with "Small Signal Parameters" for the woofer. If you have been following the last year's reviews, you know that I actually measure "Small Signal" at a more realistic level than in traditional tests. Small signal for the Klippel system can be measured as the highest voltage before the speaker starts to become nonlinear. For the MB Quart QSC 216 woofer this was at 2 watts, which is a pretty good starting point considering the very high efficiency of the speaker. The key parameters are listed in the chart below.
Parameter
Small signal 2 watts
Re (Ohms)
3.4
Qms
6.68
Qes
0.49
Qts
0.45
Fs (Hz.)
47.8
Vas (l)
17.1
Cms (mm/N)
0.73
Efficiency at 2.83 volts (dB)
91.61
So how do these stack up?
Good straight down the line. These speakers are going to be used with a subwoofer so the relatively low Q / Low Fo is not an issue. The standout parameter is the efficiency. This is even higher than the Focal Utopia, my current favorite!
Klippel testing has given us a new way to look at a speaker's linearity under power. The non-linear Motor Force (BL [X] and Compliance (Cms [X] are graphical representations of what the speaker is doing while it is playing; they tell us if everything is balanced and working together.