Alpine PLV-7 Test Report

Brand: Alpine

Model: PLV-7

Type: Test Report

V20:2007:02

GAME ON

TOP READER

GAME INTEGRATION

SYSTEMS

REVIEWED

KICKER VCVX12

SONY MEX-BT5000

BLAUPUNKT PCA 465

ZERO GRAVITY COMBO

CRITICAL MASS SS102

SHOW COVERAGE

TRIFECTA-SAN DIEGO

& IASCA WORLD FINALS-ATLANTA

ONE

ALPINE’S

BREAKTHROUGH

SUBWOOFER SYSTEM

SUBS

SIX

THE WAGONATOR TAKES TOP PRIZE AT TRIFECTA SAN DIEGO

THE

PLV-7

ELECTRONICALLY REPRINTED FROM FEBRUARY 2007

TEST REPORTS ALPINE PLV-7

WWW.CARAUDIOMAG.COM

WHEN I FIRST HEARD THAT ALPINE

ELECTRONICS WAS INTRODUCING A

NEW LINE OF AMPLIFIED SUB-

WOOFERS I HAD TO ASK MYSELF,

“DOES THE WORLD NEED ONE MORE

OVER-PRICED, UNDERPOWERED,

OVER-DRESSED, BLAM-THUD-

BLOOM BOX?” Notice that I didn’t say

“boom box.” That’s because most all-in-

one bass systems just don’t deliver. At

least not to my taste. Despite the reputa-

tion of the manufacturer, I was “under-

whelmed” when first approached with this

review.

Shortly after receiving the unit, I learned

that the Alpine PLV-7 subwoofer system

was designed specifically for use in an

SUV, station wagon, minivan or similarly

styled vehicles. Being a real-truck guy, I

assumed I’d get out of testing this bloom

box after all! Then I got a call from my

CA&E boss saying that Alpine offered to

lend us one of their SUVs for a week.

“Hmm. An Alpine vehicle for a week.”

As soon as I started my research I knew

that the PLV-7 would be very different from

anything in the category. Peering through

the acrylic window of what appears to be

a bandpass enclosure, all I could make out

was some silver tube-like structure with

three openings and no subwoofer in sight.

Obviously, the PLV-7 is far from a run-of-

the-mill–powered sub system. This thing is

special, made up of a number of new and

interesting concepts and technologies.

For this particular project, Alpine looked

outside their corporate walls to a couple of

highly regarded companies for compo-

nents and design technology to execute

the PLV-7. The confounding silver tube sit-

ting behind the enclosure’s acrylic panel is

actually the sub; or rather, a revolutionary

Linear Array Transducer (LAT) from the

Tymphany Corporation. To make this unit

work to Alpine’s specs, Whise Automotive

was contracted to aid in the design of an

innovative enclosure called Ultra Reflex.

Tymphany’ LAT is a dramatic departure

from the conventional cone subwoofer.

Your typical subwoofer displaces air

across a single cone, but the Alpine LAT

displaces air using a linear array of multiple

smaller cones. It uses six cones lined up in

a cylindrical shape, and a motor on each

ALPINE PLV-7

deSIGN

OF THE TIMES

BY ERIC

HOLDAWAY

end. To create a balanced drive design

one motor drives half of the cones, while

the other motor drives the other half in

opposition. Sound radiates through multi-

ple flow ports along the side of the hous-

ing of the LAT. The entire woofer assembly

measures just 7” in diameter by 18” long,

allowing it to go into much shallower and

narrower boxes than conventional drivers.

Tymphany claims that it is the equivalent

cone area of two 12” subwoofers and has

a frequency range of 20 to 200Hz while

using 30 percent less space (the outside

dimensions of the enclosure are 23.2” x

13.3” x 13.2”). And after listening to it, I

think they may be right.

Whise Automotive is an Australian com-

pany with extensive experience in a wide

range of acoustics and system design.

Their sister company, Precision Audio, has

patented a process called Parametric

Acoustic Modeling (PAM), which Whise

has employed in creating their patent

pending Ultra Reflex enclosure alignment.

The Alpine PLV-7 Senior Engineer, Jason

Kemmerer, was involved in working with

Whise to perform extensive computer sim-

ulations to finalize the PLV-7’s unique Ultra

CA&E

: THE ALPINE PLV SUBWOOFER SYSTEMS USE A TYMPHANY LINEAR

ARRAY TRANSDUCER. COULD YOU GIVE US A BRIEF DESCRIPTION OF

A LAT AND HOW IT WORKS?

JASON KEMMERER: The LAT is significantly dif-

ferent from traditional loudspeaker construction

in that it uses multiple smaller diaphragms in a

“push-push” configuration through a series of

rod connections to opposing motor struc-

tures. The primary advantage is the ability to

squeeze an enormous amount of cone area

into a small footprint with minimal depth, but

also the inherent cancellation of vibration and

distortion. This sounds easy enough, but actu-

ally making it work and deliver the performance

was extremely complicated. Not only did it

require extraordinary new materials and adhe-

sives with massive amounts of tooling, but also

a completely different approach to assembly

and testing.

WHILE THE LAT SUBWOOFER IS CERTAINLY UNIQUE,

WHAT INSPIRED YOU TO MAKE USE OF IT IN AN ALPINE

PRODUCT? Having already been acquainted with

several of the engineers involved with the LAT through previous

projects and contacts, I was fortunate to see it at the very early

stages of concept and prototype. Although it was a bit difficult

to imagine how it could actually be manufactured cost-effec-

tively at the time, or if it was even possible to reach the

kind of performance and durability levels necessary, I was

very interested in the concept and saw huge potential.

Sharing mutual interest and zeal for innovation,

Tymphany likewise believed that Alpine could make

excellent use of the technology in a customized plat-

form. While Alpine has been advancing subwoofer design

through development of new motor structures, suspen-

sions, thermal management, materials, etc., it is mostly a

matter of fine-tuning and pushing the limits of the traditional

loudspeaker. This was something totally new with a unique set of

challenges. Working closely with the engineers at Tymphany, we

were able to optimize the design for this first practical application,

specifically tailoring it to suit our design goals for the PLV/PLT sys-

tems and in-vehicle performance.

WHAT CHALLENGES WERE INVOLVED IN MAKING THE LAT WORK IN THE REL-

ATIVELY COMPACT LISTENING ENVIRONMENT OF A CAR OR SUV? Probably

the biggest challenge was to manage the extreme volume displace-

ment in a comparably tiny enclosure, while also achieving wide

bandwidth and high output. Those things don’t usually go together

without some other major compromise. We get the inherent advan-

tage of acoustic lift of lower frequencies in the vehicle, but the trick

was to keep the size down and get it to couple to the cabin with-

out major response problems. Achieving up-front bass is one of the

holy grails for most car audio fanatics, so it was also paramount to

optimize the design to a point to where the distortion was extreme-

ly low. While low bass should be non-directional, it’s often the dis-

tortion of most systems that draws attention and gives away its

position in the rear to the listener.

WHY WAS THE DECISION MADE TO USE WHISE AUTOMOTIVE IN THE DESIGN

OF THE ENCLOSURE OVER STANDARD LOUDSPEAKER ENCLOSURE PRO-

GRAMS? HOW DOES THE PLV-7 ENCLOSURE DIFFER FROM STANDARD

DESIGNS? Actually, there were several major reasons, but primarily

INTERVIEW:

JASONKEMMERER

Manager/Senior Engineer, Product Planning Division,

Alpine Electronics of America, Inc.

TEST REPORTS ALPINE PLV-7

CA&E 07:02

Reflex enclosure design. The computer

simulations were used to show where

internal pressures and flows within the

enclosure were not optimal, and it allowed

them to tune those patterns within the

enclosure to improve impact response,

lower distortion and extend the lowest fre-

quency limits of the enclosure. And it does

go low and get loud! If you flip ahead a lit-

tle, you will see that the maximum output

of this system was amazingly high at

134.4dB.

The final piece to this design trifecta is

a 500-watt Alpine PDX amplifier. This is no

fabricated power number, it represents

real, hardcore, hi-tech RMS watts. Its

basic architecture is the same as the stan-

dard high-speed switching PDX amps, but

the PLV-7 also utilizes patented tech-

niques for intelligent power processing

and feedback control of the subwoofer

cone — enabling tight control, high effi-

ciency and low EMI not found in other

switching amplifiers. Because it works

directly with the LAT, it is able to maintain

high control of the output response while

maintaining good efficiency; the latter

helps make for a smaller overall package.

INSTALLATION

The PLV-7 comes ready to install in just

about any system you would want to add

it to. It’s complete with traditional stereo

RCA, low-level inputs and speaker-level

balanced inputs. Having both types of

inputs allows you to add the PLV-7 to your

high-end aftermarket head unit or factory

system. The input selector switch and

“Auto ON” signal detection circuit help

make the PLV-7 more installer friendly.

With the remote bass level control knob,

the Polarity (Phase) switch, its variable

crossover (LPF 50Hz - 200 Hz @

24dB/oct) and the Bass EQ, the PLV-7 is

easily tuned to perform at it best.

I mentioned earlier that Alpine offered

up an SUV for the test session. The vehi-

cle, an Acura MDX, had a very competent

system in it — done by Transonic in

Upland, CA. It featured all Alpine products

starting with the CDA-7995 head unit and

an MRV-T420 amplifier running the front

SPX-F17m 2-way component speakers in

the doors. We ditched the normal sub-

woofer and amp in favor of the PLV-7 and

its 500 watts in the rear cargo area.

Mounting the PLV-7 was very straight-

forward. Supplied mounting plates screw

into the bottom of the enclosure before it’s

placed into the cargo area of your SUV.

You will need to pull in a minimum of an 8-

gauge power and ground wire for the 12-

volt supply. In this installation we used the

RCA inputs. We mounted the remote bass

knob; set the crossover, polarity and level;

and were ready to rock ’n’ roll.

TEST REPORTS ALPINE PLV-7

because Whise could offer something no one else could, a truly

predictive computer modeling technique for very complex systems

and a unique approach to enclosure design. Simply throwing driv-

er parameters into a typical box program and hoping everything

would work out is not the way we do things anyway, but the LAT

was an altogether different animal. Having a lot of cone area in a

small footprint would quickly become meaningless if the enclosure

ended up being huge. In order to push the limits of small enclosure

size while also striving for excellent transient response, low distor-

tion and high SPL, it was clear that we needed to try something

entirely different.

Utilizing Whise’s Ultra Reflex alignment as a starting point, we set

out to optimize the LAT’s performance in what would eventually be

nearly half of a traditional enclosure size for a driver of its relative

parameters. This necessitated effectively driving down the system

resonance with a front-loading chamber, while also dramatically

cutting out distortion with an effective acoustic lowpass. The Ultra

Reflex alignment could be considered to be an over-tuned band-

pass, but with the distinct differences of having wide bandwidth,

minimal group delay and a rising response. This poses some signif-

icant challenges to achieving an optimally flat response, requiring a

lot of power and control where it counts (both motor structure and

amplifier) as well as careful management of system resonances and

velocities. PAM was used extensively to calculate the optimum

changes in cross-sectional area as well as position and size of

stubs (dead end chambers). In total, everything in loudspeaker or

enclosure design is a series of tradeoffs, but achieving a balance

that actually sounds great vs. looking good on paper is where the

black art comes in … we built a lot of prototypes.

THE AMPLIFIERS IN THE PLV SYSTEMS ARE QUITE UNIQUE. COULD YOU

EXPLAIN TO US SOME OF THE TECHNOLOGIES INTEGRATED INTO THE AMP

AND HOW THEY BENEFIT THE OVERALL SYSTEM? Based upon our PDX

amplifier platform, the system’s amp is an intentionally band-limited

variation, coupled with a stout regulated power supply and applica-

tion-specific front end. Besides its inherent high efficiency, the PDX

platform provides particular advantages for use in the PLV/PLT as

part of a closed system. Since the load characteristics are already

known, extensive use of advanced feedback techniques could be

employed for amazing control, as well as optimizing efficient power

delivery. System performance could be further enhanced through

integrated signal shaping tailored to the application. Additionally,

with the chassis as an integrated part of the total design and pre-

determined connections between driver and amp, radiated noise

could be well controlled through intelligent patterning, filtration and

shielding.

FROM AN ACOUSTICAL POINT OF VIEW, WHAT WAS THE MOST DIFFICULT

ASPECT OF THE PLV DESIGNS? Bringing three distinct areas of new

technology together into one coherent system at the same time

was not easy. Since the LAT technology was still in the early stages

when the project began, it was difficult to foresee the final construc-

tion and alignment until quite late in the game. We couldn’t finalize

the enclosure design until there were reasonably complete drivers

and amplifiers to work with. To complicate things further, mid-

stream changes to the LAT, amplifier and enclosure were all neces-

sary for a variety of reasons, but tooling had to be locked down to

maintain the schedule. Having multiple elements in a constant state

of flux throughout the development made it particularly difficult to

determine which was having the most effect on the final acoustic

behavior and performance. When everything is interdependent, the

key to success was to quickly narrow things down and then decide

what to modify most effectively and efficiently.

INTERVIEW:

JASONKEMMERER

WWW.CARAUDIOMAG.COM

TEST REPORTS ALPINE PLV-7

Innovation is great, but how does the technology pay off? The PLV-7 didn’t

disappoint. It sounded pretty damned amazing, as a matter of fact. I listened

to a lot of music with the Alpine PLV-7. I mean, it wasn’t my vehicle, so I

spent a great number of hours driving, listening and enjoying the ride.

JAZZ

Diana Krall

LOVE SCENES

The first impression I got from the PLV-7 was its impressive impact

response. The stand-up string bass on Diana Krall’s Love Scenes album

was tight and punchy. The detail in the note shifts and string oscillation was

brilliant. String plucks and the kick drum were taut and fast; and, when you

cracked up the volume, shook your pant leg and shirt.

Score: 8.5/10

FOLK ROCK

Tracy Chapman

“HEAVEN’S HERE ON EARTH”

All of what I heard with Diana Krall was confirmed when I listened to Tracy

Chapman’s “Heaven’s Here On Earth.” The bass guitar, toms and the bass

drum delivered tight, accurate reproduction of each musical phrase. The

imaging of the bass was absolutely up front. There was no hint of the PLV-7

being mounted in the rear of the vehicle. The upper bass frequencies had no

suggestion of blooming or a lack of control.

Score: 7.5/10

RAP, POP & R&B

With rap, pop and R&B, the PLV-7 pounded out massive bass. This is no

dainty SQ sub. I began to think about the possibilities of using two or four of

these things to wake up an entire city block. The PLV-7 can move from a

drum machine bass line to acoustic bass without any problems. I played

Eminem, Usher and Will Smith. Regardless of whether the bass line went up

or down, the PLV-7 did not give up or cry out. Pretty amazing stuff.

Score: 7/10

CLASSICAL

Telarc’s Schubert

“SYMPHONY No.9”

Now for the most impressive part of the PLV-7 performance: My longtime

mentor and friend Rob Green and I were both extremely impressed with

how accurately the PLV-7 reproduced the lower frequency information on

Telarc’s 20-bit recording of Schubert’s “Symphony No.9” and Sheffield Labs

Improvisation drum tracks album. The huge Telarc bass drum was appropri-

ately loose and floppy, while the tympani and Jim Keltners drum kit were

tight and forceful. This was the area where I, as well as Rob, were the most

impressed, hearing just how faithfully the Alpine PLV-7 was able to recreate

the original sound of the recording.

Score: 9/10

ROCK

Lenny Kravitz

LENNY

While playing “Believe in Me,” the fifth track on the Lenny album, the PLV-7

stayed tight and had good articulation. The multi-layered bass-lines main-

tained distinct from one another. The bass drum and bass guitar overlap

throughout the song and are plainly definable. The PLV-7 again reproduced

these instruments with excellent impact and note delineation.

Score: 8/10

POINTS POSSIBLE ALPINE PLV-7

Overall sound quality 50 47

Tonal balance 10 09

Low frequency extension 10 08

Clarity at low volume 10 09

Clarity at high volume 10 09

Impact 10 08

Total subjective score 100 90

Ratings: Average performance is equal to 1/2 total points possible.

SUBJECTIVE SCORE CHART

MAX SPL 134.4 dB

Alpine should be very proud of their achievement with the PLV-7. Their part-

nership with Whise Automotive and Tymphany Corp. has resulted in captur-

ing lightning in a bottle… or would that be in an Ultra Reflex? Either way,

this is an uncommon product that offers extremely low distortion and

tremendously high output. It’s a subwoofer system that’s a must on your

shopping list if you’re a serious music lover or even if you’re into the boom.

The PLV-7 works for audio fanatics across the music spectrum. It’s one of

the rare combinations that can deliver it all.

CONCLUSION

SPL in car measurement at 2.83 volts, 1 meter with Bruel & Kjaer Type

2231 Level Meter set to; Un-weighted, SPL, and Fast.

LISTENING

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Alpine PLV-7 Test Report

Alpine PLV-7 Test Report

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