Is the Dirac Research AP20 a SOTA SSP? - Page 2

None of the following comments address the DIRAC Live optimization software add on to the AP-20.

Peter is correct in that you can split a single input channel into two output channels; however, this is limited to active crossover applications. In other words, you can take the input channel, define a crossover (high/low pass) and then apply that crossover to a speaker. You are limited to the two outputs (high passed/low passed). You cannot, for example create three outputs (high, mid, woofer).

You cannot, from what information I currently have, do the following:

1. split a side surround input channel into two or three side surround channels. This would be a common application where the single side surround channel needs to be routed to two different side surround speakers and have each of those side surround speakers individually managed with respect to SPL, delays, filters, etc.

2. Split the LFE input channel into multiple output channels. This would be where two, three, or four subwoofers are being used in a room and each of those subwoofers requires independent management of filters, spl, phase/delay. This is a common practice used to manage low frequency response at the seating locations.

3. This is clearly very much a "pro" piece. You are warned, before you run any EQ (including DIRAC) to be certain you have your crossovers correct (for example).

4. The AP-20 provides only three parametric filters per channel to manage low frequency response. This falls way short of what is typically required in a residential sized to room (even a properly treated room) to manage the low frequency response of subwoofers in the room. Three PEQ filters per channel are likely sufficient for very large venues; however, even with that, your multiple subwoofer channels would have to be defined, split and routed prior to the input side of the AP-20 due to the limitation preventing splitting the LFE channel into multiple output channels inside the AP-20 itself. EDIT: What would have been a better approach (in my mind anyway) is to not limit the PEQ filters by channel, rather to have 3x16 PEQ filters available which can be applied to any output channel as required (until the bank runs out of filters).

These capabilities, for example, reside within the QSC DSP 322ua, 922uz, etc. The QSC DSPs however do not have automagic room optimization. I would imagine if you wanted to use the DIRAC Live capabilities of the AP20, you could take the output of the QSC DSP as the input channels to the AP20 but I don't see that as a "clean" solution.

Hi Dennis,


True about the flexibility in x-over and splitting (OR BETTER YET MIXING) speaker outputs on the AP20 and I still have concerns about the spdif ins not doing dolby (from the owners manual) but you can also do a dual processor approach with a Meyer Galileo or QSC 3000 where you can have the AP20 in the back rack of the room and drive the digital snakes to the front racks (like in Skoll) were you could have :

[This soulution is very flexible about the ap20 shortcomings you discussed]
a QSC Cinema DCP 300Processor with the amps fed with their vga like in/out/network status connector.







Also the Meyer has a galileo 4-8 processor which does all of your good concerns plus mixing and more.

I like the online monitoring capability with the QSC DCP300 and dca1622/44 amps, how do you like these amps?

Further diagram.



The Nac 100 gives you local control of the dcp 300 where you want it.

so are these amplifiers ready for prime time? that is the question...

I've used those amplifiers many, many times. Very good. I've used the 300 once.

Thanks my friend.

2422 spec looks like a nail driver.

Our church uses the QSC product and they sound great!

Peter you should speak to Bob Lee from QSC. Occasionally he will visit the big boy forum and rattle some of the high enders...

Peter, that's easy, you saw it yourself, all mentioned DAC's meet highest level. Maybe DCS with one of their Pro units has also be taken into account (expensive!?!). The Prism might be a little ahead of the crowd, as far as I know it reclocks the signal with a spectacular accuracy. Indeed it sounds very, very natural. Can't comment on the others.

Stickler... - I had to look into the online translator As you know, one has to be the gatekeeper I like companies that provide technical details. It's a sign that they are able and willing to give some transparency and that they don't fear to be confronted with third party measurements.

Dennis, thanks for this very useful information, as I am running 4 subs these are important facts! The AP20 reminds me on a DCI projector - absolutely "naked", only equipped with a minimum of features. I guess, if full flexible routing and setting of crossovers can't be applied with the Dirac system (like it could be done with the Trinnov), some essentials would be missing.

My concern is the 5.1 to 7.1 upscale of the AP20 (Neo:6 only). As far as I know DTS Neo:6 is producing 2 mono surround back channels instead of Dolby IIx producing a stereo surround back sound. Neo:6 is for sure working in a big cinema with an array of surround back speakers, but is it also recommended when driving only 2 SB speakers? What is the superior and most accurate upscale method, Dolby IIx, THX, Logic7? Any ideas out there?

Correct


This is a subjective matter, but happily, one you can easily resolve for yourself if you have access to a current 7.1 system with modern AVR. Try PLIIx vs either EX or Neo:6 (ES Matrix). Try Ultra2, also. What I find is that while the mono effect from the rear speakers works fine for those occasional "EX" flyovers or hard panned effects, the ambience and music present the rest of the time tends to feel like a "cloud of mono" layered on top of the surround presentation. Maybe I'm overly sensitive to that, as I sit in the sweet spot of a room using direct radiators all round. The mono rear signals image as a phantom quite distinctly. But even with a 5.1 dipole system, THX provided "dynamic decorrelation" to break up the mono effect of yesteryear's Dolby Pro Logic mono surround.

Thanks Roger! Good idea, I have access to a modern system and I will see if I can detect "the cloud of mono". I know you are a sensible listener, I followed your comments on classe' & co, very helpful!

I cannot vouch for these particular pieces mentioned; but my past experience with QSC has been nothing but stellar. They really make some quality-made, GREAT sounding products.

DACS


FEATURES
Four High-Performance, Multi-Level,
Delta-Sigma Digital-to-Analog Converters
Differential Voltage Outputs
− Full-Scale Output (Differential): 6.15VPP
Supports Sampling Frequencies up to 216kHz
Typical Dynamic Performance (24-Bit Data)
− Dynamic Range (A-Weighted): 118dB
− THD+N: −100dB
Linear Phase, 8x Oversampling Digital
Interpolation Filter
Digital De-Emphasis Filters for 32kHz,
44.1kHz, and 48kHz Sampling Rates
Soft Mute Function
− All-Channel Mute via the MUTE Input Pin
− Per-Channel Mute Available in Software
Mode
Digital Attenuation (Software Mode Only)
− Attenuation Range: 0dB to −119.5dB
− 256 Steps with 0.5dB per Step
Output Phase Inversion (Software Mode Only)
Zero Data Mute (Software Mode Only)
Audio Serial Port
− Supports Left-Justified, Right-Justified,
I2S, and TDM Data Formats
− Accepts 16-, 18-, 20, and 24-Bit Two’s
Complement PCM Audio Data
Standalone or Software-Controlled
Configuration Modes
Four-Wire Serial Peripheral Interface (SPI)
Port Provides Control Register Access in
Software Mode
Power Supplies: +5V Analog, +3.3V Digital
Power Dissipation
− 203mW typical with fS = 48kHz
− 220mW typical with fS = 96kHz
− 236mW typical with fS = 192kHz
Power-Down Modes
Small 48-Lead TQFP Package
APPLICATIONS
Digital Mixing Consoles
Digital Audio Workstations
Digital Audio Effects Processors
Broadcast Studio Equipment
Surround-Sound Processors
High-End A/V Receivers
DESCRIPTION
The PCM4104 is a high-performance, four-channel
digital-to-analog (D/A) converter designed for use in
professional audio applications. The PCM4104 supports
16- to 24-bit linear PCM input data, with sampling
frequencies up to 216kHz. The PCM4104 features lower
power consumption than most comparable stereo audio
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count applications by lowering the overall power budget
required for the D/A conversion sub-system.
The PCM4104 features delta-sigma architecture,
employing a high-performance multi-level modulator
combined with a switched capacitor output filter. This
architecture yields lower out-of-band noise and a high
tolerance to system clock phase jitter. Differential voltage
outputs are provided for each channel and are well-suited
to high-performance audio applications. The differential
outputs are easily converted to a single-ended output
using an external op amp IC.
The PCM4104 includes a flexible audio serial port
interface, which supports standard and time division
multiplexed (TDM) formats. Support for TDM formats
simplifies interfacing to DSP serial ports, while supporting
a cascade connection for two PCM4104 devices. In
addition, the PCM4104 offers two configuration modes:
Standalone and Software-Controlled. The Standalone
mode provides dedicated control pins for configuring a
subset of the available PCM4104 functions, while
Software mode utilizes a serial peripheral interface (SPI)
port for accessing the complete feature set via internal
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The PCM4104 operates from a +5V analog power supply
and a +3.3V digital power supply. The digital I/O is
compatible with +3.3V logic families. The PCM4104 is
available in a TQFP-48 package.
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Peter, oh great one.

I still do not understand why you are looking at pairing a PRISM dac with the DIRAC AP20 ssp.

This will appear to be a stupid question for some but to me I'd rather be stupid for a day or two than stupid forever...

I am not running line level cables from the back rack to the front rack, so....

Digital it is.

Using two 50 foot Mogami aes/ebu snakes.

Front amp racks at SKOLL



Back Rack SOURCE at SKOLL

Except for BD hi-rez audio? The AP-20, being HDCP compliant, will not pass the PCM out when BD is used via HDMI, right?

OK it look like you are having an old fashion AMP RACK [like back in my youth we located the amps on stage, it was always a sign there were no more encores when the amp rack went black but I digress].

So you don't want to run 50' of cable from the amps to the processor. Why not run locate the amps where the processing rack is located [space permitting]? It looks like your trying to avoid what you consider long cable runs. Balanced runs are meant to be long. We run about 150-200' from stage boxes to the sound board I sent you pics of Sunday.

Based on what we discussed it looks like you have the PHC in the rack. Is thier DSP built into the speaker cabinet [like Genelec] or is it a separate box?

Just trying to understand what you want to accomplish. It just seems to me you don't need this extra DAC based on your concern of running 50 cables.

Right, yes, well better safe than sorry, plus I trust Nicksbass as he has an insane German audio consultant that makes us loonies look like school children, and he did hear it with the TRINNOV, that I am not using but he said it sounded marvelous... so why not?

You don't have six million wires like this in church, right?

Roger I will test and PM you my findings, .

Maybe not but it is better managed. Let me explain or at least try.

We have "stage boxes". Each is wired like this as I recall [I did most of them]:

- 4 x monitor connectors [Speakon connectors] basically using 12 guage speaker wire back to the amp rack.

- 10 x mic inputs [microphone or "direct box"], these run back to the board.

- 1 x VGA PC video [why I don't know]

- 2 x CAT5e [why I don't know]

- 2 x AC electrical outlet [primarly for effect pedals for the guitar players, stage amps are plugged into other dedicated floor outlets rear of stage area keeping them away from the stage box I'd say]

Also note we use balanced [cheap old Belden cable with good Amphenol connector, I think that is the brand, with a plastic hood] runs from the amp room to the board [our preamp or SSP if you will]

Then 12 guage speaker wire runs from the speaker arrays [SPL's] suspended from the ceiling as well as some Tannoy in ceiling in the foyers and small "spots" [small speakers hanging under the balcony].

OK there is also stage lighting suspended from a rail above the stage as well some fixed lighting on stage. There is a room where the AC and lighting control wiring is housed. Then it goes from there to the balcony where the lighting and Video control station is located [controls videos played via PC, song lyrics and pastors sermon notes are displayed on a Panasonic DLP using Da-Lite rear projection Screen about 12' diag 16:9].

So yes we have a ton wire but it was planned, routed and managed properly. All AV cables are in PVC conduit for ease of pulling wire.

AMEN!

From AV REV
Written by Dick Ward
Thursday, 09 September 2010




Seems the amp is showing eq for a Stewart Micro-perf. Cool!








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This is the first line of products featuring FIR, which stands for Finite Impulse Response. FIR is a new technology that's designed to give a far better speaker response than traditional active or passive methods. You'll be able to find PMA-Series Programmable Modular Amplifiers shipping in early 2011.


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The PMA-Series are as easy to operate as to install. They are the first products to offer ultra-high resolution wide-band FIR digital equalization to loudspeaker processing. The amplifier utilizes a four-channel mainframe driven and includes digital crossover filters, calibration abilities and easy to use system set-up. Each PMA amplifier is programmed through a custom Windows Utility and GUI, while system programming and calibration is carried out via a series of intuitive drop down menus. The LCD display in the front panel offers real time feedback during system setup. With these amplifiers you can rest assured of dynamic and articulate sound that usually cannot be achieved with conventional audio systems.

PHC will start shipping the PMA-Series in the first quarter of 201

RE: the church we have two rear projecton room [painted matte black inside] and one free hanging rear projection speaker so the band and pastor can keep track of it all!!!

Peter that is a ton wire but properly managed and routed I think it would work but if you feel locating an AMP RACK closer to the speakers using an AES snake is better then that is your call of course. You do this much more than I.

Curious what is the impedance level and physical shielding in the AES snake?

Next you have to get speaker wire to the amps in all that spaghetti you got going on but speaker wire is less of concern than an "interconnect".

Right speaker wire, is not a concern according to the acoustician Marc Cote of SH Acoustics.

The speakers will take an 8 gauge wire.

Here is one for 1.55 a foot.

http://www.knukonceptz.com/productDe...prodID=KAR08SS

This is the next gen Modular Processing Amp package:

Only 33 inches high. Color coordinated and all!

Hi Peter,

I'll say hi to the PRO Audio Technologies guys. Sitting in LA right having just arrived to visit their place here to listen to some systems.

IMO you are massively complicating your life right now with this design. If you are using PRO then just put a Rhapsody balanced in the rack and run the balanced cables to the PRO amps which is where their DSP resides anyway (ie A to D conversion anyway). The Prism is a nice piece but redundant in this config. We faced a similar dilema a couple of years ago when working on a bit of consulting for one of our dealers and the prism was the device that added the least to the signal chain in terms of overall fidelity achieved for the listener. Not a bad piece but no avoiding the A/D at the amp end.

As Mike has already said use a good quality star quad design XLR cable with good connector and you will run the signal for 100s of yards without issue anyway.

I am a big fan of Straightwire for speaker cables but anything with an effective guage or 10 or less should be fine even for the 1k per channel amps.

Neil

MAX, 8 ga. speaker wire? C'MON MAN!!! [My favorite spot on ESPN when the guys, Chris Berhman, Mike Ditka, Keeyshan Johnson, Chris Carter and Tom Jackson get together]

Coach Ditch: "He Key look at that bad ass speaker wire PeteMax is installing"

Tom Jackson: "Damn Pete that wire be bigger that the AC mains, well almost brother"

Chris Carter: What can I tell ya fellas... Cmon maaahhnn!

Did you know Sound Of Music is not a 7.1, but a 7.0 mix?


In contrast Running Man is a 7.1, and Toy Story 3, and Rocky Horror.



The DATASAT A20 just confirmed to me why this surround processor should be sold for $50,000.

With all due respect to the venerable Dolby expert: I don't care what Roger may say about the prologic x inclusion or no inclusion there are easy workarounds to that. These guys (developed by DTS) had their priorities straight.

If you want to know what is in the MIX, there is simply no other solution.

Because the interconnection options are tricky I am currently setup with analog out using the SMYTH Realizer (which allows you to monitor one or all of the 8 channels). The sound is terrific in analog , imagine with the insanely good digital specs!

Tonight I just started to setup the processor, already getting hdmi audio feedback. In doing so I discovered that Sound Of Music is not a 7.1 mix, Imagine what discoveries that lie ahead with this library:

http://www.blu-raystats.com/Stats/St...1&pSize=50&p=3



Re:OSD. Yes screen saver in Black after 1,2, or 5 minutes IS there.

Who are the MOFOs that decided that a RTA should not be part of every surround processor? Incompetent Bastards! If it is necessary for a cinema it should be equally available for high end homes. CEA manufacturers, CINERAMAX orders you to get your a$$ in gear on this matter. I mean come on? Does every major step forward in this Industry need to be taken by me? Doesn't any one else care? Or are we just too prostituted?

When I start referring to myself in third person it's just like the famous ex quarterback of my former acquaintance used to do. [it starts getting spooky, right?]

I recall 13 years ago, the guy ordered a crestron touchscreen on a Tuesday, calls on a Friday night from the limo (apparently after a glass of wine or three):

QB: "I want to know where my crestron is."
ME: we placed the order today after the check cleared, it should be here next week.
QB: "Damned it ! I am SUCH and SUCH" (saying his name), I demand to know in this instant where MY CRESTRON IS !"
ME: and I am Such and such (saying my name) and your touchscreen should be there next week.,.

So you like it...

$50,000? That feature has been on Lex pre-pros (even the cheap ones) for almost a decade.




What's the "easy workaround" for PLIIx? That is, what 7.1 processing does DTS offer?

Hi Sanjay,

It's not dts per se , it is the blu-ray player that can be changed via rs-232 for dts neo on 5.1 tracks.

The processor being a cinema player just routes the 5 surrounds to the 7 rears in a macro when not playing a 7.1. I will created an DOREMI server 5.1 and a doremi server 7.1 macro as such but for hdmi it will be handled in the blu-ray player via rs-232.

Now for directv ac3 decodong I have ordered a spdif ac3 and outboard dts decoder.

So yes for a typical home a couple of workarounds but on the other hand you have the makings of the ultimate sounding processor fro a Bel Air Circuit type install, and good to know of the lexicon (too bad they have other shortcomings), in any event the display in the Datasat besides being beautiful to look at , it has dirac and eq functionality as well.

Cheers!

Hi Peter,

The reason I was curious about your workaround is because, as Nicksbass posted earlier, DTS Neo only extracts a mono surround-back channel (6.1, not 7.1 like PLIIx).