Should I use this driver for TV surround sound?

mirko2

I'm a bit upset about the original Audigy 2 ZX drivers because they don't support decoding ProLogic stereo sources (upmix to 5.1). They only have those CMSS/2 upmix options which seem to be a very poor own imitation of ProLogic. There is a better ProLogic-to-5.1 upmix decoder in Creative's player, the NEO DTS thingy, but being in that player, it's quite useless: I want to watch television with 5.1 sound. So I need a ProLogic-to-5.1 decoder directly in the sound card driver and not in a specific player. Would this kx project be a solution? Does it have a ProLogic decoder in the driver and, if so, is the decoder good and configurable?

JohnMcClane

kX drivers will simply upmix your tv sound using surrounder, but you'll not get true surround sound. I'm not sure if ffdshow is able to decode prologic streams, but you can give it a try. http://www.free-codecs.com/

mirko2

> kX drivers will simply upmix your tv sound using surrounder, but you'll not get true surround sound. I'm not sure if ffdshow is able to decode prologic streams, but you can give it a try

I've in the meantime taken the courage to uninstall the Creative drivers and install kx. So far, so good: unlike the original driver, there is now an EQ before the center and bass from the center (lowpass) is routed to the bigger front speakers. Sounds good. What do you mean with not getting true surround? Is a stereo ProLogic decoder supposed to do more than the "surrounder"? As to the surrounder: I've noticed a surrounder+ and a prologica and other interesting-sounding things but do not yet understand how to use them. One barrier for experiments is the message "not enough iTRAM" error message (on that matter: if one wants to adjust treble and bass only, is the 10 band EQ the only option or is there a less-complex object that saves ram?).

Maddogg6

Well, you seem to be off to a great start, just by playing with the dsp.

I believe the iTram is the RAM attached directly to the DSP hardware. xTram being the buffer ram on PC allocated for some plugins/modules. And yes, these will limit what you can and cant do.

To make use of more effects you should look into using the 'ProFX' plugins that directly replace Prolog, Epilog and FXBuss modules.
It takes some getting used to and learning what the modules do, but its well worth it.

Experiment by right clicking in the DSP window and clearing the dsp - (no worries, re-initialize dsp, or reloading the defailt.kx file settings will get it all back)

and add the modules that spark your interest. Buts its best first to study the help file to uderstand the difference between FXBuss 0/1 - 31 lines and the outputs etc.. That was the most confusing to me, and took some time to learn and memorize the things important to me (which may not be important to you.

SAVE SETTINGS - for every siyuation..

Like I have one for watching videos, one for music production, one for MSN Messenger... and it did take some to to learn to do, but the end result was WAY worth it. (I use the default for playing the occasional game)

KX kinda forces you into learning about the 10Kx DSP - because of the flexibility it provides.

KX is an experimenters dream, cuz you wont blow anything up if you keep the speaker amplifier at a lower level.

ps. i interchange the terms 'plug-ins' and 'modules' meaning the same thing.

mirko2

Thanks for the tips!

> Buts its best first to study the help file to uderstand the difference between FXBuss 0/1 - 31 lines and the outputs etc..

About this FXBus:

1. why does the manual mention 16 buses but the router displays 32 buses (0-63)? For example, in the default setup, the E routing of the voice Wav 0/1 is connected to bus 63. Why, what is bus 63? In the DSP window, only 0-31 are visible. Is 63 the equivalent of "not used"?

2. If the Wave 0/1 stream is selected in the router, the right side shows the routings A-H for this stream. Is it implicit that A is left and B is right and C is left and D is right and so on?

3. There are volume sliders for all routings of the Wave 0/1 stream (except for routing a/b, but that's explained in the manual with internal use for panning). But I don't get any sliders for the routings of stream Wave 4/5, 6/7 etc. Why is that?

Maddogg6

SBLive (10K1 chip) has 32 mono busses, Audigy (10K2) has 64.
FXBuss 2 gives access to 32-63

The busses can be used like effect sends on a physial mixer (mixing console/desk ) for the various sources. Except, you also choose the output with it also. (on a mixer theres dedicated outputs, in KX you assign what 'pin' the signal is sent to -

for instance:
Wave0/1 is set up to send to the FXBuss 0/1 pins (2 monos, making it stereo) and 13/14 is the stereo send to the FXMix which allows you to add reverb and chorus to that.

In the KX Router
If you click on the '0' (or any of the A-H sends) - a pop out will allow you to change the pin that signal will appear at.

*I think* its because the 'X Routing' will manage the record sends (in KX Mixer.. if you remove XRouting from the DSP - the KX Mixer looses the vol sliders for wav recording (master and wave 01/ 2/3, 4/5, 6/7) in the recording screen.

If you adjust Sends A/B in the KX router also, it could get really confusing, you need to do too many adjustments to make recording work. ??
I could be wrong, but thats my opinion/guess. XRouting is a bit counter intuitive (IMHO) and its name makes no implication to its purpose.

Also back to FX Buss, I look at it like this... The FX Buss plug-in/module - is NOT a plug in per se like a delay or reverb is - but represents, and gives interface to, the DSP's internal routings ability much like the Prolog and Epilog give access to the physical (and virtual - ASIO) ins and outs. To me, they should be called something more 'mixer like' as Ive never seen a 'prolog' on a phyical mixer (those are programming terms as far as I recall/seen) - Phyical & Virtual ins/outs - would have been more 'musician' friendly.

JohnMcClane

The surrounder plugin does not decode the prologic stream. It's a simple upmix.

Surrounder+ is almost identical to surrounder - surrounder only supports up to 5.1 speakers. Prologica is a more simple plugin, that will not allow to do bass redirection and has not as many speaker modes as the surrounder plugin.

mirko2

> The surrounder plugin does not decode the prologic stream. It's a simple upmix

What's the difference? Prologic is, I believe, a simple addition of a center signal and a rear signal (both mono) to L and R in the sound studio. The signals are added in a way that allows removal in a ProLogic decoder: the center signal is added to L and R, so getting it back is as simple as extracting the monaural part from L/R. The rear signal is added to L and R but with the phase shifted by 180 degree, ie. one channel gets the signal upside-down. As with the center signal, getting it back is as easy as a few additions and substractions. So in what way does the surrounder not execute these primitive steps and is "a simple upmix"?

On getting good suround sound: I understand that many ProLogic decoders have options such as speaker distance [m], speaker position [degree], speaker size [small|large], room size [m*m] and vertical speaker position [m]. Distance probably translates into the [ms] options of the surrounder element (Creative's driver has a good THX calibration console; surrounder needs something like that, too, or at least I have no clue what to enter in the ms fields). Room size probably translates into reverb (?) and speaker size into bass redirection (?). I wonder to what the position [degrees] and the vertical position [m]translate?

Totally unrelated: what element in the DSP window implements a stereo volume slider? I would like to balance the front channels after the prologica/surrounder (in a simple setup with ProFX elements). Or are there mono sliders only so that two of those have to be inserted into the L/R paths?

mirko2

I understand that part. But each router block (the A-H sends) is related to a signal with two channels. For example, Wave 0 and Wave 1 in case of the eight Wave 0/1 routings. So it must be an implicit, hard-coded fact that the first routing (A) routes Wave 0 and the second routing (B) routes Wave 1 and then (routing C) it starts with Wave 0 again? The router is extremly counter-intuive. Much more logical visual representations come to mind...

Maddogg6

Yes - you are correct

WAVE 0 - A,C,E,G
WAVE 1 - B,D,F,H

As I understand it.

And yes - better lables even could be less confusing (like WAVE0/1 - would make more sense (when relating to a physical mixer) if were called WAVE 1 L/R..... BUT it wouldnt make sense when working in surround. Thus Im sure its why the lables arent more specific, and you just have to remember - 0/1 is the 'reminder' of those busses being 2 channels.

Maddogg6

Some of those adjustments are in the 'TIME BALANCE' plugin I mentioned earlier - btw... TIME = DISTANCE FROM SPEAKER - and not playback speed (which is what I thought it was ay first.) I dont think vertical position is part of it tho.

There are several volumes and mixers with adjustments.
Theres FXMix2 - which is a 4 St input mixer with 1 send. (like 8x4)
Theres St. Vol. and various sums (i never really use)
Stereo mix (with gain too)


AND.... MX6 - is a 6 stereo In - with 2 sends, a main and record bus.
The 'M' and 'R' are MAIN and RECORD bus enables - which are dis-abled when adding the module - so no sound until those are enabled.

(its like a 12x8 mixer - but hardwired with no pans - so more like a 6x4 mixer)

ThomasBarnes (? spelling ? - a user in these forums) has a nice tutorial on setting up ProFX - its aimed at using for Sonar - but the DSP setup technique is the same.

Experiment around - adding modules - dbl click on them to get the GUI. And look to see what it does. Not all mudules/plug-ins have a gui.

Hope that helps

JohnMcClane

Sorry I thought you know what I mean. kX drivers do not decode the stream. The surrounder plugIn and also the prologica plugin simply upmix the stereo source into multichannel sound according to your settings. If you select Rear=Front, then all speakers will have the same output (similiar to stereo surround from creative), if you choose Movie Mode you'll get a more cinematic effect, where the center speaker will be in foreground. But you'll not get positional sound, as the center and surround streams are not decoded.

Maddogg6

It sounds like your describing a old matrix (and crappy - Dolby Pro Logic) way of surround before discrete surround became to be - by simple adding and subtracting l and r to derive a 'surround' effect - then added a delay line (10 - 50ms or so)for the rear speakers so you can 'electrically' emulate more distance between your ears and the rear speakers sound relative to the front channels. Then add a lowpass filter for a subwoofer (before the decoding) and a mixer/band pass filter for the center (after decoding the front channels).

discrete (Dolby Digital) surround on the other hand has no such encodings and all channels are their own channels.

- if using proper software (as I have read - FFDSHOW (audio), a filter somewhat like a codec - that many players can utilize) can properly decode (seperate from a single multi-channel stream) dolby digital encoded material as the decoding is done BEFORE the audio enters the 10Kx DSP. You may need to make a DSP setup to do so - like directly connecting respective FXBus signals to the Epilogs 5.1 (L,R,C,RR,RL) outputs. (Note, thse signals on the xRouting are 'Compass based' - N - north, S-south E W. etc... )

Now, the surrounder/prolocica, as John mentioned - just takes normal stereo and makes it so all your 5.1 speakers will make some sound.(I had wondered about the technique used in those plugins, if the did do the add/subtract method to 'upmix')

Read this:
http://www.hardwareheaven.com/3-d-audio/55041-surrounder-explained.html

Its my understanding modern discrete digital surround requires MORE than the 48Khz sample rate as locked in to the 10Kx DSP - thus decoding with a 10Kx DSP needs software, as the dsp wont be able to on its own. The CL drivers Im sure did the decoding.

Using FFDSHOW *should* decode BEFORE running any signal through the DSP Like CL drivers would have had to - and I was under the impression *WOULD* in fact give a discrete 5.1 surround decoding. As long as, of course, a 5.1 encoded signal is sent through the KX WAVE HQ (as I understand it, the only sound device capable of playing anything other than 48Khz streams) - or possibly the discrete channels are routed (with in the decoding software) to the appropriate output device (IE. 2/3 front, 4/5 rear, 6/7 LFE & center)

I need a 5.1 speaker system so I can better experiment/understand/explain... but thats how I understand it as Im no expert on the subject and I have much to learn my self Im sure.

I DO KNOW - 'surround' is a generic marketing term that has turned into a huge fiascko (IMHO) - meant to confuse consumers.

heres some good explanation of the different surrounds that have been out (and note some of the dates for some of the systems/techniques):
http://www.informit.com/articles/art...?p=341486&rl=1
and
http://www.surroundassociates.com/fqmain.html

Now it seems they just went and added matrix to discrete to get 6.1 and 7.1 - Im sure thats just giving plenty of consumers headaches too.

mirko2

Yes! I'm talking about getting a surround effect from analog stereo material (old videos, TV). Isn't that what Dolby Surround, Dolby ProLogic, CMSS and DTS NEO:6 are all about?! I'm not talking about discrete digital multichannel audio.

@John:
Really? I was under the impression matrix-decoding is too easy not to be implemented (see below). And I don't see any other way to get the cinematic effect you are mentioning. Well, maybe a bandpass that routes frequencies associated with human speech to the center. Are you absolutely, 100% sure that the surrounder module does not implement matrix decoding?

--- quote from doom site

Dolby Pro Logic (1 or 2 or whatever) is a decoding algorithm. [...The] DPL decoder is about interpolating more than two channels out of a 2ch track. (like in a 2.0 --> 5.1 process). The DPL/DPL2 implements an adaptive 2x5 matrix:

[Lt Rt] * MTX = [L R C SL SR LFE]'

The left channel output, L, would be equal in this case to : Lt * MTX(1,1) + Rt * MTX(2,1)
(and so on for R, C, SL,..)

This matrix is adaptive and that means that the coefficients change from time to time, according to the input data. The dpl algorithm doesn't "care" if the source is a dolby surround material or a plain stereo track.

Let's think of this very primitive process with a static dpl-like matrix. Given a 5.1 source L, R, C, SL, SR, LFE we would create a 2ch downmixed track with channels Lt & Rt:

Lt=L+C+(SL+SR)
Rt=R+C-(SL+SR)

The (static) decoding process would look like:

Lr=Lt;
Rr=Rt;
Cr=(Lr+Lt)/2; [=L+C+(SL+SR)+R+C-(SL+SR)=L+R+C]
Sr=(Lr-Lt)/2; [=L+C+(SL+SR)-R-C+(SL+SR)=(L-R)/2+(SL+SR)]

creating Lt & Rt is principly what Dolby Surround Downmix is about, and creating Lr, Rr, Cr, Sr is principly what Dolby Pro Logic is about. Aas mentioned before, the (adaptive) DPL algorithm can reproduce 4/5/6 channels out of ANY 2ch source, but in case the source was encoded as Dolby Surround, the decoded track would be very close to the original. As you can now understand, Dolby Surround "encoding" is a very simple process of simply weighted summings of 5.0/5.1 channels into two channels.

As for DPL2 & Dolby Surround 2, in Dolby Surround (1), we would sum the surround channels into one mono channel, and treat them just like in the example as "(SL+SR)", while in Dolby Surround 2 we would "help" DPL2 seperating them back by giving different weights to each channel. For instance:

Lt=L+C+SL+0.5*Sr
Rt=R+C-SR-0.5*Sl

That's it.

Note: all above equations are only for demonstration! For the real downmix coefficients download BS_Downmix.dll from my webpage.

---

(I don't know why the matrix has to be adaptive but to offer a guess, it changes if it detects speech?)

JohnMcClane

Yes I'm sure - you can take a look at the source code if you don't believe me. The surrounder does no decoding in any form - it simply copies your front output to center and rear.

mirko2

I could look at the source code all day long without getting any smarter What about the prologica plug-in. The name suggests...

Maddogg6

With out looking at (or even understanding it) the prologica plugin - its name implys it will do the matrix decoding expected in a 'Dolby Pro Logic' manner.

And, there is one point I'd like to address about John saying sourounder only copies - there IS, at the very least some delay and EQ happening when 5.1 speakers and surround mode 'ON' is selected. Thus, makes me wonder if a matrix has been implemented in it (in a newer version than what John has??). Which IS adjustable. (Rear speaker width/distance (delay). It creates a pleasent effect with 4 speakers - which is all I have.

Even looking at source code wouldnt mean anything to me as Im no programmer.
But it may JUST add delay and a comb filter possibly.

BUT, to answer your original question.
The Prologica module has NO adjustments. BUT, the time balance plug-in *could* be used with it to give (at least some) of the adjustments (speaker distances) you mentioned. I dont beleive 'placement/locations' vertical nor horizontal are implemented - it 'sounds' (from reading the thread) like its hard coded into the plugin, and has been tweaked in different versions. (I cant check cuz I didnt install it as its not compiled for KX V3638h, that I have to use)
look here:
http://www.hardwareheaven.com/effects-dsp/76213-i-made-timebalance-plugin.html

I say, install KX - give it ago - many people are very happy with the results - if your JUST looking to have 5.1 speakers be used when playing stereo material. It will, with plenty of adjustments and ability to make your own prologic decoder if you have C++ (M$ Visual C++ 6.0 is best as I understand) experience and understand microcode. All the source code is available and the SDK is included (it was with V3538h anyway) - the time balance plug in, on the otherhand, was developed after - thus I dont have the source or the compiled code for my version of KX. And can only regurgitate whats in the thread I linked to.

Maddogg6

BTW - the prologica module has a stereo in and 5 outputs.

Heres the micro code for prologica.

I beleive it to be doing 'Dolby Pro Logic' decoding - but the micro code is mostly greek to me. But I know its much more than just routing signals.

PS - micro code - 'MACS' = Multiply and carry Saturation (Saturation is like Assmblers 'Overflow' - sorta i think its a DSP equivelent of the overflow anyway)

The iTRAM is the delay - which you CAN adjust in the micro code. (its using 20ms - which I think is the DPL spec. - but many decoders would allow adjusting that anyway)

UPDATE:
I did more testing with speakers in surround mode(s)
Common conditions in all tests...

5.1 ALtec Lansing ANALOG system (bought cheapest for this test) - will return tomorrow. hehe

DVD - 'Monster in Law ( I know, not greatest surround movie - but was pronounced enough for me to hear the different channels)

Win XP SP 2 -
K-LITE codec pack installed (provided AC3 filter as I recall - in addition to all the other codecs)
Win DVD 7 Installed (wont work with KX - no audio - but provides DVD codecs)
AC3 filter - set as 3/2 SW 5.1 Channels - direct sound device


format below is:
CONDITIONS
TEST
RESULTS

C: DSP CLEARED - WMP10 w/ AC3 filter - direct sound device.
T:DVD - 5.1 Dolby Digital Surround Encoded
R:5.1 source works great - set speaker mode in WMP10 options/dvd/advanced (match the reported stream detected for best results) Audio TAB.

C:DSP - default (re-init DSP) then change speaker mode to 5.1 and 'ON'
T: Need for speed Underground II - only game I have loaded
R:No discrete surround.

C:DSP - using 1 src, prologica and KXLT2
T1:DVD - 2channel - surround turned off (AC3 dilter settings in WMP10)
T2:NFSUGII
R1&2:Prologica - sure seems like a Matric (DPL) decoder with delayed rears (20ms according to mivrocode).

C:DSP - default (re-init DSP) then change speaker mode to 5.1 and 'ON'
T1:DVD - 2channel - surround turned off (AC3 dilter settings in WMP10)
T2:NFSUGII
R1&2: Surrounder - does similar as prologica - with adjustable delay for rears and even an adjustble 'rear width' via what sounds like a comb filter.

So I am pretty confident to say the SB0350 (Audigy 2 ZS PLAT) with KX V3538H will decode matrix and discrete surround.

mirko2

Creative's mediasource player has a stereo to 6.1 upmix called DTS NEO 6. The manual says it's mutually exclusive with their CMSS upmix, so I assume it's a DSP program and not a software solution in the player. Would it be possible to dump this program out of the DSP and try it out with kx?

Maddogg6

I understood the media source player would actually decode DTS and is not just upmix. - But ONLY if played in their mediasource player - which as I understand is the *only* way to play DVD-A discs, DVD-A discs being the only thing I've seen thats DTS encoded personally.

I still think (quite sure) that theres significant PC code that would accompany the micro code for the DTS playback/decoding.

DVD-A - Ive read is looking to avoid pirating in a big way... so much so, I think it will ultimately backfire on them - I could be wrong but the DTS site reaks of 'EXPENSIVE TO LICENSE'.

The DTS site is not very informative as to how it works - a quick look didnt find any technical specs even. - My guess its all about DRM and anti-piracy more than its about improved end user experience.

http://www.dts.com/

for anyone who care to look.

mirko2

> I understood the media source player would actually decode DTS and is not just upmix. - But ONLY if played in their mediasource player - which as I understand is the *only* way to play DVD-A discs, DVD-A discs being the only thing I've seen thats DTS encoded personally.

The name might be misleading. I don't think DTS NEO:6 is a DTS decoder at all. I've used it with stereo sources. It provides good matrix decoding for stereo sources. See this:

http://www.dtsonline.com/media/uploads/pdfs/neo6.pdf


What I find interesting is the bit about steering. The MatrixMixer (a free DirectShow filter that implements ProLogic) has a similar feature, if I understand "steering" correctly: its decoding matrix is adjusted dynamically, depending on content. For example, if the frequency band associated with human speech has a strong signal, the center could get a more prominent role. I wonder if something like that can be implemented in DSP hardware? If NEO:6 is just a DSP program and one could dump the code... NEO doesn't have any configurable options, just two modes: movie and music.

Maddogg6

That wasn't my impression - I beleive(d) it use()s the CMSS to do a matrix decoding IF no DTS material is detected.
DTS - specs out 5.1 only - the move to even more channels is what the NEO added - like - a simulation of surround for 2 channel - Just like CMSS does.

It also adds a combo of discrete and matrix decoding to 'create a back channel from 5.1 encoded material' -ala 6.1 (I imagine just like DPL did for front center channel - strip the 'normally' MONO or common to both rear channels and send to a rear center channel. Neo claims to get 7.1 also.

Ill admit I have plenty to learn about DTS and its specs - as Im not even sure if thats Dolby Digital Surround compatable or not) - it looks like no if I had to guess.

DPL IS matrix encoded surround- first off. DPL added specs like delaying the rear channels 20 ms. and some filtering also as I recall.

I have built simple DPL circuits using OPAMP to derive the (L+R/L-R, filter then add delay for rear) back in tech school, when fox first started their TV channel (anyone remeber AIlien Nation - I built the decoder JUST for that TV show- and IT WAS broabcast in DPL -btw.), only audiophiles had it in their homes previously and was starting to be found in low-mid end consumer receivers.

ANY stereo signal would produce sound at the rear. Mono signals would always be predominant in the front center - Front L/R were NOT affected - while the mathmatics of deriving the rears produced weak and un-dynamic sound (but still present) until a DPL stereo encoded signal was put through it - THEN the rears were more pronounced and dynamic - no electronics changed - ONLY the source material.

I have since see (more like heard) exact results in all the receivers that claimed DPL compiance (Sony, Yamaha etc..)

Its ('steering') inherent to the DPL system and was intentional to keep compatibility in existing theater systems (this was when 'home theaters' were but a dream for all but movie producers) as well as reduce their upgrade costs.

DPL was created to 'piggyback' a plain stereo system to ADD additional channels IF you had a DPL decoder.

YES!. - in a few ways - adjustable - and Prologic (20 ms delay to rears, non adjustable)

You could - send a (analog) stereo signal from your dvd player - (like JUST the rear channels) and derive a center channel -
Or The front AND rears - to get 7.1 side channels.
Using the DPL plug-in in KX - if your DVD gives 5.1 analog decoding.

In reguards to 'steering' - Its just marketing verbage - and was explained above.

I dont understand why DPL is of such great interest anyway - as Digital is by far better - AND IS supported in KX (with SW decoding - like AC3 filter)
Yes, it allows use of more than 2 speakers if playing straight stereo material, but there are other ways also, like adding reverb and chorus to make a rear channel - add a bandpass filter to make a center channel - all simple to do in KX.

DTS on my DVD player - is what provides the digital audio outs - SO, there are obviously more aspects to DTS specs than I know about. Im thinking DTS - IS WHAT a PCM spdif stream encoded for DDS 5.1 is called or specified as and stored as on a dvd..??.

DPL - I never even see that anymore as it was an inferior surround encodeing/decoding scheme compared to the current digital.

6.1 and 7.1 just adds matrix decoding to derive additional channels from the 5.1 dolby. And of cource suffers from the same seperation and dynamics issues DPL did, with some improvements Im sure. I dont buy into the 6.1 and 7.1 until I see that 6.1 and 7.1 are discrete and NOT matrix derived - as DTS admits to and is even marketing and admint matrix is not as good as discrete.

My next tests will be if my A2ZS will decode that digital audio from my DVD player - but I may need an optical cable to do so, if its coax Ill do it soon, if it is optical - I may never - hehe.

mirko2

Big pile of movies recorded from dvb-s card, that's why. Many stations, even though digital, still don't have AC3.

I tried the bandpass idea, doesn't work. Impossible to find settings that work with all voices. Some go down to subwoofer range, like Sam Elliott, and others let glass shatter. If you put a bandpass before that, it will sound weird. At the moment, I'm using a lowpass. Not to change/highlight the center but to extract very low bass (50Hz, width=5). The center is too small to reproduce good bass. That goes through 8db gain and is added to large front speakers. If I'm not posting tommorow, my neigbours have killed me

Maddogg6

I used a bandpass (paralleling NOT in series) for center channel simulation - that ALWAYS workes for MONO voices.

Ex
signal chain in DSP...
Stereo IN - MIXER A w/ send - MIXER B w/ send - Front L/R out

Mixer A send 1: Reverb - MIXER B
Mixer A Send 2: SUMM - bandpass (~1Khz - low Q) - FRONT OUT

Mixer B Send 1: SUM - LOWPASS - LFE out
Mixer B Send 2: Stereo Chorus - Rear L/R out.

I used sends and return mixer channels to adjust releative levels.

This is what I have now for stereo - 'upmix' - and sounds pretty good for TV, MP3's, CD's. etc.

This arrangement sounds better than KX prologica plug-in, as prologica has some hefty filtering (sounds like 2Khz thru 4Khz or so, with out a means convenient to measure) to the rears unless DPL encoded signals are sent through, then lower freqs pass through, as well as more 'head room'.

Also something to note: surround is best when all speakers are matched (freq response, sensitivity etc..) - EQ just wont do any justice to compensate. - so as you say, your center speaker cant hadle much bass - you need a better center channel speaker.

I had mis-matched speakers prior to yesterday - as my results with out were un- acceptable to my ears (1 pr real cheap, and1 pr better for monitors).

Im sure more experimenting will yeild better results - and dont be affraid to.


AND - kill your neighbors BEFORE the kill you.. LOL

Maddogg6

Ok... after much testeing and listening...

Prologica ia very good at decoding Dolby Prologic encoded material...
StarTrek TNG - the rear channels are *almost* completely silent (that signature noise thats supposed to be the ship is there and somewhat faint) - UNLTIL explosions, sound effects, transporter.. etc... then the rear channels are quite pronounced.

for plain old stereo encoded material - there are noisy artifacts affecting the hi-mids (above 2.5Khz) comming through the rears and passing the rears throuh a low q bandpass set to ~1.5Khz cleaned it up a bit. So it appears the filter i *thought* DPL specs out for rears hasn't been implemented - and assumes another KX module would be placed between its outputs and the phyical output (on epilog or KxLT).

I also tried mixing the original stereo with the prologicas fronts with a little of the center channel together to make non DPL encoded material sound better with minimal loss to the original DPL effect.

But for best stereo only material - adding a reverb (efx reverb station) and st. chorus to the rear channels sounds way better and gives a nice, warm ambiance. - Straight copy front to rear is also good too.

I need a DVD to test more of Discrete surround decoding from an SPDIF in from my set top dvd player - I should have one in 1-2 days (i dont keep a library of movies on hand).

I should have gotten surround speakers before - cuz its fun playing with KX and surround actually - I always just went to the TV room for surround sound and such prviously - but now I can watch while I work now - then again, I may never get any work done now.. lol

mirko2

> So it appears the filter i *thought* DPL specs out for rears hasn't been implemented

There is no filter in ProLogic II. ProLogic, ie. the version before, had a 7 KHz lowpass or shelf (what is that?) in the surround path. By the way, this draft almost looks loke a kx diagram:

http://www.audioholics.com/techtips/...Prologic_2.pdf

This document mentions steering, too, and here is another one that explains it (it's not just markting talk and probably not implemente in the kx driver because it requires logic, it's not just a filter):

http://www.homecinemachoice.com/arti...PrologicII.php

It's apparently about precise SL/SR positioning and to avoid leaking between center and rear:

"When the decoder input signal is left or right heavy by a certain amount of dB, and the left/right inputs are driven out of phase, the decoder steering logic senses this as an SL or SR signal and will therefore be output by one surround channel or the other."

(in other words, it makes surround pseudo-stereo, you can have effects coming out of one corner)

Maddogg6

well, you keep changing the subject matter - DTS - to DPL to DPLII - theyre not the same.
And youre 'suffering' from the confusion they want you to have in trying to uderstand all the surround sound technology.
This confusion gets people to upgrade their equipment more frequently. - not just consumers but those that license thier technology (Hollywood, equip manufacturers etc.)

DONT EVEN get me started on the whole THX thing.

If you require to have the DSP do ALL the decoding to decode everything out there - no KX isnt what you want. Its DSP is locked (not a KX limit, but CL's DSP) at 48Khz - which seriously hinders what it can do for muti-channel decoding on its own and MUST have a software to do much of it. - Just like creative does. Things like delay and filter are where the 10Kx dsp come in.

Note: CL makes no claim to be PLII - only Dolby Digital EX
http://www.dolby.com/consumer/techno..._overview.html
http://www.soundblaster.com/products...4&product=4915

CL USES CMSS INSTEAD of DPL or DPLII - KX on the other hand give you DPL with a plugin thats easy (and fun, imho) to play with.

Thats it Im trademarking MY OWN - MadDigital Virtual Surround - that I developed within KX.

mirko2

Not really, the topic of this thread is two channel TV surround sound and that includes all matrix decoders, from ProLogic and ProLogic II over CMSS to DTS NEO:6

I don't feel like having (many) problems understanding the technology. I have problems understanding how kx relates to it because so little documentation exists. All you get is names like "surrounder" and "prologica" and little information what is in these black boxes unless you understand the DSP code.

Well, if you say so. The DSP is a mystery to me. I briefly looked at the documentation and was surprised to learn that elementary operations like division are not supported and require weird mathematics (power series). I suppose it is not very versatile?

Maddogg6

My mistake, sorry - TV shows out here doesnt show (anymore) if they are in encoded dolby (DPL/DPLII/EX/SX/XP/123/ABC - j/k lol) or not -
ATC (Digital 'HDTV' in the U.S.) assumes AC3 - but not 'advertised' at the beginning of the show like they used to when DPL/DPL first became 'popular' tho - except possibly in the closing credits.

Well, my point was your not comparing apples to apples, when you take my statements and apply it to something I wasnt talking about.

Dolby wants money to use the words 'dolby' or 'pro logic'. To do so with out license would equate to law suites/seize and desist orders and such..

To better explain the 'suurounder' plug in - it is bassically a plugin that provides a stereo to muti-channel upmix - like CMSS or DPL does - probably not in same manner as that would also be patent infringement - but is similar. It also provides an convenient interface to 'turn off' the 'CMSS like' effect and to pass through multi channel sound when it is present/desired.

The prologica plug in 'sounds like' DPL (not II) - while IT DOES produce output to the rears for ANY stereo material fed to it - it dosent sound very good on its own and I found requires additional filtering for *some* cases like MP3s (its compression atrifacts - if audible to begin with - are more pronounced in the SL/RL - which is exacly what I would expect because of the nature of the 2 beasts), Audio CDS on the other hand - artifacts are less of an issue and moves more into odd filtering effects (missing singers voice, or in an un-expected channel) un less it was encoded for DPL. This is the same effect on my receiver also btw.

There isn't a DPLII equivelent plug-in in KX, but im pretty sure if you knew C++ and microcode it is possible. Or if a DPLII filter is around, Im pretty sure it would work.

The Prologic decoder you mentioned before (as a filter like the AC3 filter) - would probably work - just as the AC3 filter does (the AC3 filter just makes use of system sound devices - direct sound or wave device) - but does the decoding and passes the mutli-channel sound to the default direct sound or wave device, in my case is set to wave HQ - and the seperated multi-channel sound is present on the pins of the P16V plugin (not connected in the default dsp setup- btw).

Yes, the 10Kx dsp's are not the most power dsps - just the most powerful that you will find in a relatively low cost consumer sound card.
Not to mention it only deals with numbers between -1 and 1, any thing else like whole numbers - requires a host PC's interaction. This may be true for all audio dsps..??

Also,
You missed part of my quote that was significant - it said:

The 'ON ITS OWN' - part, in otherwords - CL claims to do DTS:NEO - the 48Kxz that the DSP is locked at does prohibit the a decoding of dolby digital surround ALL on its own - there must be software to decode it - AC3 filter for instance as Im sure the Media Player DTS:NEO is (probably) using software to 'help decode' in addition to using the dsp for the chores that take most burden from the PC and still not use too much of the DSP resources.

KX plugins are no different - there is some effects that are dsp micro code only - and there are ones that have C++ code (thats compiled for the PC to execute) in addition to the microcode executed by the DSP.

KX does include an SDK so if you knew more about pragramming than me, and have a C++ compliler with the M$ MFC libraries (as found in M$ Visual Studio 6) - anything is possible (just about).

KX is very flxible - the DSP is what I would call 'Pro AM' - as it is quite flexible - but its 48Khz limit means it is not as high of quality as DSPs youd find in newer professional recording studios.

Which brings me to my next point - KX's flexibility was aimed more at music production than games/voip/movie decoding etc.. Although games / voip / and software DPL/DPLII/DDS/DTS are possible - wasnt 'optimized' for in KX. KX biggest strong point is the flexibility in routing and ability to make your own effects (and learn about dsp techniques) - and superior (to CL driver) ASIO performance - which is mostly used in music production.

I am convinced (even with CL drivers) DOLBY/DTS/THX surround decoding/compliance needs additional software and not just a driver. CL drivers included some where KX expects you to use the alternatives/equivelents available elsewhere (like the AC3 filter or that DPL filter one you mentioned - do you know where I can find that?)

Example that supports this statement - CL driver package is like 25MB and KX is like 5MB (?? about) - CL is adding much more than JUST a driver - and its got to be the THX, DOLBY/DTS decoder, DVD-A player - (Media Center DTS:NEO, as I recall), demo wav files etc... (plus all the advertisement stuff of course - also absent in KX) which are reported by many as 'buggy'.

IF IT SAYS DOLBY - they paid for a license, or should have - I doubt many will as Im pretty sure it isnt cheap. CL can afford to pay it tho.

I cant compare the surround quality in KX to CL as I refuse to install their driver 'package' just to test (lol). The surround (all in all - minus DTS encoded material - ?? none available to test) in KX is as good as, and even better ( ie. DPL), than my (Sony) receiver that I watch most movies/TV through in my living room. DPL on my sony (for stereo only) sounds like crap - but has the DPL logo on it.

KX does require some learning to realize its power and flexibilty - but the great thing is.. its possible - without any DSP/C++ knowledge at all.

I created my own DSP set up (a few actually) for stereo (upmix to 5.1) play back that sounds better to me than CMSS or prologica/DPL (my opinion, enhanced by the 'I did my self' prejudices Im sure) - something only available in KX for the $$$. I could send you some DSP setup files if youd like some examples of some of my techniques. It is optimized for my speakers im sure, but it will give you an idea on how to make and ajust your own.

Its alot of fun too.

mirko2

> The 'ON ITS OWN' - part, in otherwords - CL claims to do DTS:NEO - the 48Kxz that the DSP is locked at does prohibit the a decoding of dolby digital surround ALL on its own

DTS NEO:6 (or just "NEO:6") is just a matrix decoder for a stereo signal, like ProLogic. It's not the DTS you seem to think about (Dolby Digital). The following review compares matrix decoders for stereo signals, including NEO:6 (doesn't get a good rating):
http://www.hometheaterhifi.com/volum...c2-3-2001.html

> There isn't a DPLII equivelent plug-in in KX, but im pretty sure if you knew C++ and microcode it is possible.

You'd have to have the DPL II algorithm... So far, I haven't found it anywhere (beyond cute diagrams). Is it possible that DPL II is still Dolby's secret?

Of all programs on my computer, including Creative's drivers, several media players, kx, open source filters etc., only Intervideo's WinDVD player has a ProLogic II option and the official logo. Curiously, while this program seems to be built entirely on DirectShow filters, I can not find an Intervideo ProLogic II DirectShow filter. The closest I have found is "InterVideo Audio Processor Fx", which has a TruSourroundXT tab. I don't think that's the ProLogic II filter. If anybody knows of a ProLogic II DirectShow filter (or how to use the WinDVD filter, if it exists), please report.

> KX plugins are no different - there is some effects that are dsp micro code only - and there are ones that have C++ code (thats compiled for the PC to execute) in addition to the microcode executed by the DSP.

But the C/C++ code is only for the user interface, right? There is no way to call C/C++ code from DSP code, right? Otherwise (if one could break out of DSP code and have C/C++ code in the signal path), it would be possible to encode EAX sound into AC3 with a software codec But I believe that's not possible: Once you are "on" the card, you are n the card and everything happens there, "outside" the computer. Or?

> I am convinced (even with CL drivers) DOLBY/DTS/THX surround decoding/compliance needs additional software and not just a driver

If you look at the list of installed DirectShow filters, you will find a whole lot from Creative, including AC3, Karaoke, CMSS3, etc. (but maybe these are just to initialize the DSP, so it may not mean anything).

> Its alot of fun too.

Yes

PS: Why don't you post your kx graphs? I don't have a 2x2 system but would be intersted anyway.