Speaker Asylum: REVIEW: Pinnacle Loudspeakers Quantum Plasma QP9W Speakers by mr.bear

Model:	Quantum Plasma QP9W
Category:	Speakers
Suggested Retail Price:	$849
Description:	Combined Left-Center-Right, three-channel system
Manufacturer URL:	Pinnacle Loudspeakers

Review by mr.bear on November 18, 2015 at 22:56:39
IP Address: 108.38.55.213 Add Your Review
for the Quantum Plasma QP9W

The Pinnacle Quantum Plasma QP9W is designed as a compact flat bar 38"(W) x 4 3/8"(H) x 4"(D) weighing 14 lbs. that can be hung on the wall. This passive "Soundbar" was intended to be used as a combined Left-Center-Right, three-channel system. Instead I'm using all three channels as a single center speaker, which is the subject of this review. (My goals for 'home theater" are collateral to music listening and are served well with a 3.1 arrangement.) This Pinnacle speaker provides open, spacious sound, good voice reproduction, and decent dynamics.

The Pinnacle QP9W is constructed with three internal chambers, each housing a 1" fabric dome tweeter crossed over at 5 kHz to two, 3" polymer cone woofers with butyl rubber surrounds. Specified frequency response is 95 - 21 kHz (+/- 6 dB); 86 dB per channel @ 1 Watt / 1 Meter which feel about right. Each of the little 2-way systems has individual 5-way, gold-plated binding posts.

Recommended amplifier power is 20-200 wpc; nominal impedance is 8 Ohms. A newer version with the same name uses an aluminum enclosure but maintains similar specifications. List price for one speaker was around $850US; a clean used one was available locally for $50.

It's difficult to add a center-channel speaker to a 2-channel rig that one has listened to for years. The overall voices need to match well enough and it's hard to avoid a boxy sound with tiny drivers and the awkward mounting position on the wall near the television screen. When my Thiel CS3 stereo speakers were built there was no matching center channel and I've tried several alternatives. Some audiophiles might assert a center speaker is unnecessary, especially for 2 people in a small room, more so for stereo speakers that image decently. But a well-matched center speaker improves the intelligibility of dialog for movies and television- a real help for those BBC shows where everyone mumbles with strong Irish accents!

In my system the Pinnacle is being driven with a total 100wrms via an Adcom GFA-5002, one channel feeding the center, one channel feeding the right and left wired in series. (The series wiring => -3dB for the 16 ohms, + 3dB for the combined output of the L+R, so ROUGHLY the same sensitivity as the single center.) The L+R and C summed output adds 3dB, yielding a net sensitivity of 89dB. My rough measurements with an SPL meter seem to indicate about the same sensitivity as my Thiels- a nominal 89dB. (I think that's valid, since all my Adcom power amps have 29dB gain).With the levels adjusted carefully and a HP crossover of 80Hz, movie sound is clear and clean without being overly bright.

It has a relaxed natural voice, a little tending to warmth, rendering speech distinguishable without strain. Integrates well with the subwoofer. All of which is due in part thanks to my Lexicon MC-12 preamp's processing capability and infinite adjustability. The Pinnacle is capable of peak output levels comparable to the Thiels (driven by a larger Adcom GFA-5500) seemingly without strain.

Listening to music on the QP9W alone (in mono) reveals no glaringly obvious response abnormalities, something less than perfectly transparent midrange. The best thing about the Pinnacle it is that it doesn't mess up the overall sound of my Thiels when the movie is playing music. (The Pinnacle is, of course, turned off for music listening.)

Overall, it's a good performer and integrates well within a more "traditional" stereo system to provide excellent dialog intelligibility for movies and television without distorting music accompanying the video. It's attractive and contemporary looking, well-made, and seems a bargain in the used market.

Product Weakness:	Not very sensitive, OK using all three channels as a single center (see text)
Product Strengths:	Good dialog reproduction, integrates well, a bargain.

Associated Equipment for this Review:

Amplifier: Adcom 5002 (for center ch.)
Preamplifier (or None if Integrated): Lexicon MC12
Sources (CDP/Turntable): Various
Speakers: Thiel CS3
Cables/Interconnects: In-wall quad 14 ga. stranded
Music Used (Genre/Selections): Live jazz DVD's, various movies.
Room Size (LxWxH): 19ft x 24ft x 10ft
Room Comments/Treatments: N.A.
Time Period/Length of Audition: 6 weeks
Other (Power Conditioner etc.): N.A.
Type of Audition/Review: Product Owner

Amplifier:	Adcom 5002 (for center ch.)
Preamplifier (or None if Integrated):	Lexicon MC12
Sources (CDP/Turntable):	Various
Speakers:	Thiel CS3
Cables/Interconnects:	In-wall quad 14 ga. stranded
Music Used (Genre/Selections):	Live jazz DVD's, various movies.
Room Size (LxWxH):	19ft x 24ft x 10ft
Room Comments/Treatments:	N.A.
Time Period/Length of Audition:	6 weeks
Other (Power Conditioner etc.):	N.A.
Type of Audition/Review:	Product Owner