Arc Audio PS8 Processor v6.indd

Arc Audio PS8 Processor v6.indd
T E S T
E P O R
R
T
PS8
DIGITAL SIGNAL PROCESSOR
WORDS AND MEASUREMENTS BY GARRY SPRINGGAY
uring the winter CES show in Las Vegas, I had the opportunity to listen to many demo vehicles. One
PSC
that really stood out for me was a white Saturn in the Arc Audio booth. I spent a considerable amount
(Optional Controller)
of time listening to the car, and having the system explained to me by Arc Audio’s Fred Lynch. Fred
explained the whole system, from the truly wonderful Black series speakers to the amplification, but as it turned
out, at the heart of this simply brilliant sounding system was an all-new, ultra high-end signal processor called the PS8.
D
I asked Fred for details on the PS8 and
what I learned was nothing short of jawdropping. The project's technical mastermind is none other than the legendary
Robert Zeff, a man who has nothing to prove
to anyone when it comes to designing great
sounding gear. With Robert's technical
prowess, the combined efforts of ARC's PS8
project team and Fred's extensive experience in tuning high-end audio competition
cars, and the result is an especially good
blend of performance, adjustment power,
and simplicity of use.
Of course I quickly finagled one for review,
and Fred was kind enough to personally fly out
to Phoenix and hand carry one of the first production samples to my lab. We went through
the processor and it’s rather remarkable
software, and this review is the result of what I
saw, heard, and learned.
I’d like to say right here, that there is absolutely no way I can even begin to do justice to
all the features, tricks, innovations, and general cool things about the PS8 in a magazine
100
review. However, I will do my best to give you a
taste of what this incredible product can do.
› INTRODUCTION
The basics go like this. The PS8 is a
relatively small black box type of product
that is controlled and adjusted primarily by a
laptop computer, connected by a USB cable.
I say primarily, because there are provisions
to change settings and configurations with
simple switches as well, allowing certain
functions to be adjusted from the driver’s
seat without a PC required.
The PS8 is much more than your typical
DSP processor. It has been designed from the
beginning to be able to be used as a solution
for several quite different applications, from
OEM interfacing, to fundamental system
tuning and control, to Expert level tuning
suited perfectly to the highest performance
competition class, audiophile systems.
One of the great things about the Arc Audio
PS8 is that it can be as easy to use, or as complicated to use as the operator prefers. There
are four distinct modes of operation, Standard,
OEM, Intermediate, and Expert. In the Expert
mode, the range of adjustments, settings, and
variables is truly staggering. Also, a special note
regarding Expert Mode... Expert mode is only
accessible after accepting an electronic release
of liability disclaimer and acceptance of the
risks of using the power and features available.
This special warning and waiver is incorporated
into the software graphic user interface, and
the disclaimer pops up upon entering the
expert mode, and will not unlock the expert
user mode until the agreement is accepted.
As I’ve said before, expert mode is for highly
advanced and experienced users and you are
supposed to know what you’re doing! Expert
mode is not supported by ARC Audio technical
support for tuning advice, nor is how to tune
with a specific feature. In expert mode, you are
on your own, and you’d better know what you’re
doing! I strongly recommend that this mode
only be used by true experts, and people who
have been properly trained and understand the
fantastic amount of tuning power available.
PERFORMANCE AUTO & SOUND
Arc Audio PS8 Processor v6.indd 1
12-06-05 2:31 PM
Digital Signal ProceSSor
The feature set below describes the basic
characteristics and functions built into the
core DSP circuitry:
arc auDio PS8
manipulated. That sort of transparency is the trademark of a truly high performance processor, and the PS8 gets very high marks in that regard. Folks, this one sounds amazing, mostly
because you simply can’t hear it.
› PERFORMANCE / BENCH MEASUREMENTS
300,000,000 mac/S (multiply accumulates per second).
dual mac cycles per clock.
dual 72-bit accumulators (the most accurate in
the industry).
24,000 x 32 Sram, 2,000 blocks (assignable to
data or program).
Internal watch-dog dSP lock-up prevention.
maximum 32-bit @ 192 kHz.
Supports 32-bit audio sample I/o between dSP chips.
192 kHz SPdIf transmitter.
multi-channel dSd direct stream digital Sacd input.
Supports two different input fs sample rates.
dual processing path capability.
codec / digital-to-analog converter 32-bit operation capable of 192 kHz.
S/n ratio analog input 96.5 dBa unity gain 1:1.
S/n ratio digital input 107.4 dBa.
dedicated dual 72-bit algorithm volume control
processors.
170 mHz primary processing.
48-bit internal audio sequence processing.
So as you can see, at the digital
core is a high-performance, 32bit, user-programmable, fixedpoint DSP that is capable of
performing two multiply-andaccumulate (MAC) operations
per clock cycle. The DSP core
has eight 72-bit accumulators, four X- and four Y-data
registers, and 12 index registers. Coupled to the DSP core is a
flexible DMA engine. The DMA engine
can move data between peripherals such as
the serial control port (SCP), digital audio
input (DAI) and digital audio output (DAO),
or any DSP core memory, all without the
intervention of the DSP.
Now before I go into all the features, functions and the dizzying array of adjustments
that this thing is capable of, I thought it
would be a good time to tell you about how
good it sounds, and measures.
You see, in addition to the 12 volt car audio
addiction I have, I also do a lot of work with
professional live sound and studio products
and high end home audio based products. As
a result, I have heard a lot of DSP processors.
Some are very good, and some are frankly
lousy. One way I differentiate between the
two, is to listen for digital artifacts or what
I call “processed sound”. In this regard, the
Arc Audio PS8 is one of the most musical
processors I have ever heard. This truly is a
black box full of digital magic, because when
you listen to a properly tuned system through
the PS8, you have no idea the signal is being
102
From a technical, bench measurement perspective, the PS8 is equally as impressive. The
unit has a truly formidable set of credentials on the test bench. It will deliver over 8.5 volts
on each output, with an excellent output impedance of only 22 ohms. Signal to noise is always a tough spec on DSP powered products, but thanks to the use of absolutely first class
components and the engineering brilliance of Robert Zeff, this processor has an analog
S/N ratio of better than -95dBA at an output level of 4 Vrms. I measured THD levels in the
0.005% range, and stereo separation was a phenomenal -88dB!
I could go on about the sound quality and the measured specs, but I would run out of space
to describe some of the features and expert user mode details, so that’s what we’ll move on to.
› PS8 FEATURES & MODULES
Auto Recovery USB (A.R.U.) technology
Designed and engineered specifically for the Arc Audio PS8 by Zeff, the A.R.U. technology allows for faults and cable issues, including accidental disconnect or damaged USB cables, power
failure or power loss on PC or in the vehicle, critical faults in USB communication and more without the processor locking up, losing unsaved user-defined settings or requiring a full reset. This
key benefit allows users to simply reinstate the last known user-defined tuning
position after a failure or power loss even if it hasn’t been saved as a preset or
setting file on the PC once reestablishing normal operating conditions.
Real-time update and memory management
PC communication while in user interface mode updates in real
time allowing you to hear and save every adjustment as it is made.
User settings files are processed internally as data files rather than
active audio files. In this manner, the PS8 can process the user-defined
adjustments at a higher resolution without the traditional loss of bandwidth, frequency response or signal transparency in the digital domain.
Four-stage audiophile switching power supply
The PS8 uses a dedicated proprietary four-stage switching power supply for the various critical digital and analog components. There’s an isolated 14-volt power supply used specifically
for the OLED display controller (sold separately) and op amps
as well as dedicated power supply channels for the PS8’s codec and DSP main chips. To prevent unwanted noise, special
ground isolation circuitry eliminates the possibility of signal
interference or induced noises between the PS8’s analog and
digital components, thus improving S/N ratio.
Arc Audio proprietary electronic unit identification protocol
Every PS8 DSP comes with discrete embedded processor
identification and serial number that allows users and dealers to retrieve
the unit’s individual Arc Audio serial registration code. This security measure functions even if
typical identifiers have been removed by unauthorized sellers
or thieves. The serial registration and identification code is
embedded into the PS8’s microprocessor and is viewable by connecting to the PC interface.
Interchangeable output core technology
Audiophile-grade ultra high resolution Texas
Instruments 5532 output devices improve the
overall dynamic response and sound quality
levels and enable the PS8 to provide the highest
Performance auto & Sound
Arc Audio PS8 Processor v6.indd 2
12-06-05 2:26 PM
Digital Signal ProceSSor
arc auDio PS8
standards of audio reproduction. However, no
matter how good the OEM parts are, someone
always thinks their favorite part is better. To
support the audiophile community, the PS8
is equipped with zero insertion loss audiograde IC dip sockets to allow the most critical
of tweakers to interchange output devices to
their device of choice. However, you’re basically on your own if you do this as Arc Audio is
not liable for damage or side effects caused
by changing the factory 5532 output devices.
Take my advice: leave the 5532s in there – op
amps don’t get much better.
DSP-controlled remote turn-on circuit
To prevent unwanted pops and snaps caused by some components in the system
turning on before or after others, the PS8 has a cleverly-designed DSP-triggered remote
turn-on output technology to control the critical timing of your system amplifiers’ on and
off sequences. User-defined controls allow you to define when amplifiers turn on and off
through the PC interface from one millisecond to 10 seconds before and after the processor
is turned on or off thru the system's source unit.
Signal input stage and input compatibility
The PS8 includes six channels of RCA
inputs capable of accepting over seven volts
of signal. High-level inputs can be utilized via
a supplied RCA to speaker lead "pigtail" adaptor and pressing the input level switch, which
also resets the input impedance from 10,000
ohms to 200 ohms. The high-level input network will accept up to about 20 volts of signal
for most OEM integration applications.
Digital coaxial and fiber optic inputs
Priority-assignable digital coaxial and fiber
optic inputs allow users to run at the highest
level of acoustical reference on today’s most
advanced high-end source units. (Use of the
digital input circuit requires the PSC
optional accessory controller.)
3.5 mm unbalanced
signal input
A 3.5 mm input jack is
included for auxiliary input
sources such as portable
music players or navigation
devices. The input is assignable
as a “navi” style input, which causes
the PS8 to mute when it senses signal
from this input for navigation voice commands.
When this input is used, it disables the RCA
input channels five and six and takes their position on the user interface signal router panel.
104
Preset interface trigger
To enable the toggling between three separate onboard
user-defined presets, the PS8 provides a trigger lead option, which allows users to toggle though user defined
settings with a single vehicle-mounted three-way toggle
switch without the need of the controller or PC interface.
DC barrel jack power connection for home use
The PS8 offers a built-in DC barrel jack on the power
terminal side of the main unit. This feature allows users to
use the PS8 as a home audio DSP processor by simply plugging in a properly-rated AC/DC power supply. (Not Included)
Bluetooth expansion module (Optional Accessory)
The PS8 has advanced Bluetooth communications provisions offering a wide variety of additional source and possible future control applications for the PS8. The PS8BTM expansion
module (sold separately) allows users to stream audio from portable MP3 players or media storage devices into the PS8; and, use the PS8 and media devices as sources (optional PS8 control
station required). The PS8BTM expansion module is Bluetooth 2.1 compliant and is a CE, IC and
FCC qualified registered product. It has a range of up to 30 meters (depending on application
and installation of the PS8 unit) and can support up to 14 simultaneous Bluetooth profiles. All of
this wireless voodoo magic works via an on-board proprietary integrated antenna.
User-definable channel labelling, naming and function
assignment
User-defined channel name
assignment capability allows you
to customize the names of all
input and output channels with
up to 10 characters each. These
names are then represented on
the input screen, crossovers,
equalizer, signal delay, output
levels etc.
Performance auto & Sound
Arc Audio PS8 Processor v6.indd 3
12-06-05 2:26 PM
Digital Signal Processor
VU meters
One of my favorite features (and something
that comes in very handy when tuning) has to
be the on-board VU meters in the software.
These individual channel meters offer users the
ability to view signal levels within the PS8 and
multiple points in the signal chain. The signal
input VU meter allows users to view the incoming signal in real time, including clipping level
and independent channel level of all inputs.
An output VU meter allows users to visualize
the signal levels through the PS8, post mixer/
router, crossover, equalizer, signal delay et al
helping ensure the channel assignments are
correct and that there’s no internal clipping of
any of the individual DSP component sections
before the output stage. The signal output VU
meter allows users to see the signal of all individual channels as they leave the DSP into the
PS8’s output stage allowing users to use the
signal output trim panel to adjust each channel
for optimum signal whilst avoiding signal clipping or unwanted distortion.
Full-time system channel muting control
For ease in tuning, the PS8 offers users
full-time independent channel or full system
muting from any interface panel of the PS8’s
software utility without having to change
screens or functions to access this feature.
One-step firmware update
When the PS8 is connected to the internet
via a PC, users can quickly check for updates
for the DSP and controller by simply pressing
the “Check for Firmware Updates” button. This
also automatically turns the user’s computer
into a network station without ever requiring
the user to locate a particular website, user
password or login info and electronically con-
106
Arc Audio PS8
nects the PS8 with Arc Audio’s server. Upon connecting to
the server thru the user interface, the current PS8 main
unit's firmware [As well as the controller's firmware] is
confirmed and verified then indicating to the user if there
is a new version available. Then with a simple click of a
button, seconds later your PS8 [or controller] is updated
with the latest and greatest firmware version.
The whole process of firmware and system updates
averages about 60 seconds and does not require external power supplies. Plus, thanks to a builtin fail-safe protocol, there’s no risk of catastrophic consequences should the update process be
interrupted for any reason. Lynch demonstrated this for me by first unplugging the USB cable
during an update (and then removing the battery from his laptop during a subsequent demonstration) and the system simply returned to its previous state with no lock-ups, crashes or
anything. Astonishingly, it just worked perfectly no matter what stupidity we tried throwing at it.
World Wide Web tech support
The PS8 PC interface allows Arc Audio to take technical support to a whole new meaning.
Thanks to Web-based technical support that can be connected directly to your PS8 hardware
anywhere in the world, the tech support person can take control of it via the Internet with user
authorization from Arc Audio’s main headquarters or even remote field locations via a secure
server. This remote control capability allows the support staff to quickly and easily diagnose
and correct problems without an endless barrage of questions.
› PS8 EXPERT MODE TUNING FEATURES
Input signal menu and capabilities
∫∫User adjustable input signal level per individual channel.
∫∫Variable adjustability of input signal from -64 dB to -/+24 dB in 0.25 dB per step increments
per individual channel.
∫∫User-defined auto sense priority interface
(lets users choose what input source to
default to if the main unit senses the signal – such as defaulting to Bluetooth from
normal analog RCA operation etc.).
∫∫Analog – RCA and 3.5 mm inputs operation only.
∫∫Digital – Coaxial, optical and Bluetooth
(requires optional PS8BTM module and
PSC controller).
∫∫Wired lead input/output status.
Signal path mixer/router panel and capabilities
∫∫Input/output-configurable channel assignment.
∫∫100% fully open fully variable mixer panel controls allows user to define the signal path from
any input channel to any output channel.
∫∫All mixer/router channel in/out assignments are fully variable allowing users to select any level
of input signal to its out channel assignment for stereo, mixed stereo, mixed mono, sum mono
signal assignments and more.
∫∫User-friendly sum/mono button allows users to combine any input combination of paired
channels into a single 100% un-clipped
summed mono signal for subwoofer
applications.
∫∫Numerical value displays for all possible
assignment paths.
∫∫User adjustments can be made by manual entry, mouse pointer via dial control,
double key stroke (channel on and off) or
intuitive arrow key controls.
∫∫Individual 180-degree signal phase invert
on all eight input and output channels.
Performance Auto & Sound
Arc Audio PS8 Processor v6.indd 4
12-06-05 2:26 PM
Digital Signal ProceSSor
arc auDio PS8
BANDPASS CROSSOVER EXAMPLES FREQUENCY RESPONSE
Cogent Audio Labs
BANDPASS CROSSOVER EXAMPLES - FREQUENCY RESPONSE
+6
+4
+2
-0
-2
-4
-6
-8
-10
-12
-14
d
B
r
-16
-18
-20
-22
-24
-26
-28
-30
-32
-34
-36
-38
-40
20
50
100
200
500
1k
2k
5k
10k
20k
10k
20k
Hz
ARC AUDIO
BANDPASS CROSSOVER EXAMPLES - FREQUENCY RESPONSE
0dB = 2.0 Vrm s
CROSSOVER SLOPE EXAMPLES FREQUENCY RESPONSE
Cogent Audio Labs
CROSSOVER SLOPE EXAMPLES - FREQUENCY RESPONSE
+6
+4
+2
-0
-2
-4
-6
-8
-10
-12
-14
Crossover settings panel
∫ Eight channels out fully variable type crossovers: all pass, high pass, low pass, band pass.
∫ User-defined mixable crossover slopes and damping filter types allow users to select any
variation of pre-defined slope or filter type allowing users the capability to mix any variation
of slope vs. damping configuration on the HP and LP portions of a bandpass crossover.
∫ User-defined damping selection on all bands of all channels at 6, 12, 18, 24, 30, 36, 42 and
48 decibels (allowing users to select any variation of slope on any filter type with abilities for
different slopes on both HP and LP portions of BP configuration).
∫ User-defined damping options on all bands of all channels, including Butterworth, LinkwitzRiley, Bessel and variable “Q” function.
∫ User-defined variable frequency selection on every band of every channel from 20 Hz through
20 kHz with incredible frequency definition (such as 6,523.43 Hz if so desired).
∫ Slider, keyboard arrow key and numerical entry options for all crossover settings.
∫ User-defined frequency limitations platform to prevent adjustments being made below defined frequency points and prevent damage to speakers during the tuning process.
Phase/signal delay panel
∫ Eight channels of user-defined signal delay.
∫ Delay capability of up to 10 milliseconds per channel (adjustable in
.01/.02 ms increments).
∫ Numerical display readout on all channels for real-time delay status.
∫ Slider, keyboard arrow key and numerical entry options for all delay
settings.
∫ Global/relative likability of any combination of channels (allows user
to adjust the delay on each channel individually and then in pairs or all
globally without the loss of an individual channel’s previous settings).
∫ Individual 180-degree signal phase invert on all eight output channels
108
d
B
r
-16
-18
-20
-22
-24
-26
-28
-30
-32
-34
-36
-38
-40
20
50
100
200
500
1k
2k
5k
Hz
ARC AUDIO
CROSSOVER SLOPE EXAMPLES - FREQUENCY RESPONSE
0dB = 2.0 Vrm s
Possible crossover variations
∫ 1,999,800 crossover frequency points per
filter type, per channel.
∫ 3,999,000 possible crossover frequency
points per channel.
∫ 31,992,000 possible crossover points on the
PS8 across eight output channels.
∫ Over 4,000,000,000 possible crossover types
and configurations on the entire PS8.
Output signal panel
∫ User-adjustable signal levels on each channel have zero through
-40 dB of attenuation (allowing user to reduce signal output for
driving amplifiers that cannot accept high-level signal input and for
advanced system calibrations).
∫ There are also front + rear, left + right, center and bass level assignable faders accessible on this panel for even more defined
tuning and level settings with the optional PSC controller.
Performance auto & Sound
Arc Audio PS8 Processor v6.indd 5
12-06-05 2:26 PM
Digital Signal ProceSSor
arc auDio PS8
› EQUALIZATION PANELS
One-third octave equalizer
∫ Eight channels of 31-band third-octave equalization per
channel.
∫ Traditional third-octave EQ points from 20 Hz to 20 kHz.
∫ Adjustable in 0.25 dB per step increments (each band per
channel adjustable to +/- 24 dB).
∫ Global/relative/individual likability of any combination of
channels allowing users to adjust the EQ on each channel
individually and then in pairs or globally without the loss of
the previous individual channel’s settings.
∫ EQ channel plotting available on one or all eight channels
simultaneously.
Parametric equalizer
∫ Eight channels of fully-open architecture parametric
equalization.
∫ User-defined parametric equalization from one to 31
bands per channel.
∫ User-defined frequency centers on all 31 bands of each of
the eight channels selectable from from 20 Hz to 20 kHz
(any frequency including 16th/octave harmonic frequencies and mid tones).
∫ User defined “Q” on all user defined and factory frequencies on all channels.
∫ “Q” adjustable from 0.1 to 24.0 allowing users the opportunity to select “Q” variations from very wide to extremely
sharp EQ points (for applications such as 31 bands of customizable EQ notch filters on every channel if so desired).
∫ Adjustable in 0.25 dB per step increments (each band per
channel adjustable to +/- 24 dB).
∫ EQ channel plotting available on one or all eight channels
simultaneously.
TECHNICAL DATA
output Impedance
Input Impedance (rca)
Input Impedance (Speaker Level)
frequency response
Voltage Input Sensitivity (rca)
-22 ohms
-10K ohms
-200 ohms
10Hz - 23.5kHz @ .82dB max deviation
-28mV-7.1V
Voltage Input Sensitivity (Speaker Level)
- 72mV - 20V
Gain range
tHd 1V Input to output unity gain
-88dB
-.005% tHd
aux Input min/max range
- 214mV - 4.1V
channel Separation
88dB
maximum output voltage
8.7V
analog in/out S/n
- 107.4 dB
digital input to output tHd
- .002% tHd
Bluetooth input to output S/n
MAX FLAT - FREQUENCY RESPONSE
CROSSTALK VS FREQUENCY
MAX FLAT - FREQUENCY RESPONSE
Cogent Audio Labs
+2.8
+2.6
EQUALIZER FILTER Q - FREQUENCY RESPONSE
CROSSTALK vs FREQUENCY
Cogent Audio Labs
+0
+26
-5
+25
+2.2
-15
+2
-20
+1.8
-25
+1.6
+1.4
+1.2
+21
+20
+19
-35
+18
-40
+0.8
-45
+0.6
+23
+22
-30
+1
+17
+16
+15
-50
+0.4
+14
-55
+0.2
d
B
+0
-0.2
d
B
r
-60
-65
-0.4
-1
-80
-1.2
-85
-1.4
+12
+11
+9
-75
-0.8
+13
+10
-70
-0.6
+8
+7
+6
-90
+5
-95
+4
-2
-100
+3
-2.2
-105
-1.6
-1.8
-2.4
+1
+0
-115
-2.8
-3
10
+2
-110
-2.6
20
50
100
200
500
1k
2k
5k
10k
20k
30k
-120
-1
600
700
800
900
1k
MAX FLAT - FREQUENCY RESPONSE
Ref - 2.0Vrm s
2k
3k
Hz
Hz
ARC AUDIO PS8
EQUALIZER FILTER Q - FREQUENCY RESPONSE
+24
-10
+2.4
110
> arcaudio.com
- 104.8 dB
+3
d
B
r
For additional photos and exclusive video, visit
pasmag.com/arcPS8processor
-96.5dB
digital input to output S/n
Cogent Audio Labs
For more information on the PS8 please visit
www.arcaudio.com/product-pages/processors/dsp/ps8.asp
ARC AUDIO PS8
CROSSTALK (Stereo Separation) Ref 1.0V output
4k
5k
6k
7k
8k
9k 10k
-2
20
50
100
200
500
1k
2k
5k
10k
20k
Hz
ARC AUDIO
EQUALIZER FILTER "Q" ADJUSTMENTS - FREQUENCY RESPONSE
0dB = 2.0 Vrm s
Performance auto & Sound
Arc Audio PS8 Processor v6.indd 6
12-06-05 2:26 PM
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement