Smokes your problems, coughs fresh air.

Creative Audigy 2 ZS design flaws

I would really like to know what the designers at Creative Labs have in mind when they design sound cards. Their cards seem to be broken by design. The Live card was bad enough with its random collection of DACs and DPS’s, but the Audigy 2 ZS seems no better. Aside from the fact that it’s advertised as 96 kHz and 24 bit, which it isn’t, it has serious design issues. I had some sound anomalies, so I decided to measure and test. I found:

  • The output for LFE and center actually should output LFE and center on separate channels, but it outputs them mono, in the center channel… This makes it impossible to connect to an external amplifier and have it apply the proper 10 dB boost on the LFE signal.
  • The LFE and Center channel distort at maximum gain (or minimum attenuation: 0 dB), which is easily heard by sine testing. I had to reduce all channels by 3.2 dB to avoid distortion.
  • The center and LFE channels are 6 dB quiter than the other channels when they’re all the same in the mixer. With a test tone, all channels measured 0.78V, while LFE or center measured 0.39V. That is, LFE measured 0, center measured 0.39V with both center and LFE signal.
  • The LFE/center output has a significantly louder noise floor than the other channels.

Really, what monkey designs this?

14 Comments

  1. halfgaar

    I bought an Asus Xonar DX with AV200 chip (even though the specs said it should be AV100, if I recall correctly). Anyway, this card is properly designed and everything works as it should.

    ALSA, however, is another matter. Because this card doesn’t do hardware mixing (which is a good thing; long story), ALSA uses dmix to mix sources by default. To do so, it has to resample all source streams (otherwise it can’t sum samples), which it apparently does so at 48 kHz. So, when I play an HD 96 kHz audio file, mplayer reports it’s being output at 48 kHz. I had to set the default device to the bare hardware to get Mplayer to play it at 96 kHz. Of course, this means that I can only play one thing at a time. Normally not a problem, but sometimes I like to use Skype when playing a game.

    Really, why does ALSA resample to 48 kHz on a card that is native 192 kHz? I’ll take this up on the mailing list.

  2. Michael

    Regarding the LFE/Center channel issues, Donnie27 suggests in this thread using a 4 connecter 3.5mm plug/cable – http://hardforum.com/showthread.php?t=844340

    I haven’t tried it personally.

  3. halfgaar

    I doubt that will fix it, actually.

  4. Jim

    Hi halfgaar, I was thinking of buying two of these cards for use in my old an old Windows 98SE and Windows 2000 gaming machines

    Just to clarify are your saying that out of the box by default all the analogue outputs on this card distort but you can fix this by reducing ALL channel volume levels in the creative surround mixer by 3.2 db ?

    “LFE measured 0, center measured 0.39V with both center and LFE signal”

    Are you saying if you play sounds on the center channel and the LFE at the same time you only hear the center channel signal? ie their is no lfe signal whatsoever one the centre/sub jack ?

    If so can the bass crossover in the creative speaker settings be set to 0hz. So that any lfe frequencies are sent to the center/sub jack?
    This is assuming that 5.1 /7.1 games are actually coded using 5.1 /7.1 and not 5.0 / 7.0

    As I was going to use an Onkyo receiver to connect these cards up to a 7.1 THX speaker setup do you think this solution would work in my particular case

    Reduce All channels by 3.2db in the creative surround mixer to get rid of distortion

    Increase the center channel volume on the ONKYO receiver by 6db, to match the other channel levels

    Set the crossover frequency in the creative speaker settings to 80hz (THX spec)or 0hz if lfe signal output not possible

    Set the crossover to 80hz on the OONKYO so bass on the center/sub jack channel (if their is bass on that) is redirected to the lfe channel

    Set the lfe channel volume on the ONKYO to either 0 or +10db depending on weather the particular game being played uses 0 or –10 db headroom for lfe.

    Thanks for reading,
    Jim

  5. Jim

    To clarify I’d be using :

    1x Three Pole/Pin 3.5mm Mini Jack to 2x RCA Phono adapter for the Front Left / Right speakers

    1x Three Pole/Pin 3.5mm Mini Jack to 2x RCA Phono adapter for the Rear Left / Right speakers

    1x Four Pole/Pin 3.5mm Mini Jack to 3x RCA Phono adapter for the Side Left / Right + Centre/Sub speakers

  6. halfgaar

    Only the center/sub channel distorts when set at max volume. But yes, you would need reduce all channels by a small amount to fix that.

    About the LFE / center output being on one channel; it’s literally that. There is a two-channel output 3.5 mm jack that is supposed to contain one center and one LFE channel. Center is ‘left’, LFE is ‘right’. However, they are both mixed in the left channel. So, if you plug in into your creative speakers, the bass will try to come from the center channel. However, because it has a bass cross-over, it will probably redirect it to the bass module.

    Game audio doesn’t have an LFE channel BTW. And if it does, they don’t know what LFE really means. In theater recording, an extra LFE channel is recorded at -10 dB gain, resulting in an AC3, DTS, whatever recording with the .1 channel in it. Samples in games are mostly ordinary stereo/mono WAV files, which do not have LFE information. However, a lot of people, including sound card driver writers, seem to think that this .1 output on the soundcard should contain bass information from the other channels. This is not the case, but sadly does happen. The .1 output from the computer should contain the LFE signal, and your receiver should boost the gain by 10 dB, to give a signal that is at the proper level to feed to a subwoofer.

    I suspect that a creative 7.1 speaker set does not apply this 10 dB boost on the .1 input, though. But, this information is hard to find.

    BTW, your 3.5 to 3 RCA won’t work. All 3.5 mm outputs are stereo. The audigy only has 5.1 out, in three cables (well, 5.0 out, actually, because of that LFE bug).

  7. Jim

    Thanks for answering so fast.

    I was under the impression from this manual http://support.creative.com/manuals/download.aspx?nDownloadId=7127&prodName=Audigy%202%20ZS%20&%20Audigy%202%20ZS%20Platinum%20Users%20Guide%20English

    that the jack output closest to the firewire port was using an alternative four pole/pin jack instead of the standard 3 pole/pin stereo audio jacks the other line out’s are using. And it was thus outputting three channels in the “7.1” mode, really 7.0 mode.
    1. mixed center/lfe channel
    2. left side channel
    3. right side channel

    If this is the case you can buy 4 pole/pin jack to rca adapters http://www.cables2u.co.uk/high-quality-35mm-pole-jack-p-622.html?gclid=CITZ7MOrproCFfMPtAodRWoAvw that are normally used for stereo+video from what I can gather.

    So my best bet might be to leave all the channels at max gain in the creative mixer minus the center/lfe and decrease that by 3.2 db below the rest of the channels and then increase the centre/lfe on the Onkyo by 9.2db (6 + 3.2) to compensate. And set the creative mixer to 80hz crossover and set the Onkyo to 80hz crossover and the lfe to 0db headroom as you were saying PC games don’t use LFE.

    This is assuming the creative mixer is respecting the crossover setting and redirecting all the sub 80-hz signals to the center/lfe channel and not duplicating them.

    Thanks again,
    Jim

  8. halfgaar

    I didn’t know about that 3 channel cable, that’s good to know.

    Can you even configure a custom boost on the LFE channel? In read a good article somewhere some time ago (I don’t remember where or which one) which explained that if you’re using separate components for amplification and media playing, the LFE channel often has the wrong boost. Some receivers don’t allow you to change it, leaving it stuck at either 0 dB or 10 dB. Some media players have the same problem. So, you could even end up with +20 dB boost, if you have the wrong combination.

    But, actually, the LFE boost is not going to be helpful for you, because you don’t have a separate LFE signal to boost, because it’s mixed in with the center.

  9. halfgaar

    BTW, if you could apply the LFE boost separately, you would need to:

    • Set LFE to -3.2
    • Set LFE boost to 10-3.2 = 6.8

    The LFE channel boosted is then taken up by the bass management system, and redirect to the proper output channels. This can be 100% on the sub, or when you don’t have one, it can split it 50/50 over the speakers. Or, if you have a sub and small speakers, it will send the boosted LFE channel to the sub, plus the low frequency content of your other inputs.

    But, if your soundcard also applies bass redirection, things might interfere. If your Onkyo has full bass management, I would configure it there.

  10. Jim

    I’d certainly be interested to know if you still have the LFE channel missing using the four pole jack.

    The Onkyo allows for custom level management on all channels including LFE.

    I don’t understand the +6.8db (10-3.2) LFE adjustment. I was thinking

    – 3.2db in software mixer (to fix distortion)
    + 6.0db in amp (to compensate for lower volume relative to other channels)
    This is assuming for my use as strictly for games which you say don’t use the LFE so I won’t need +10db LFE headroom adjustment

  11. Jim

    Woops, I meant to say

    interested to know if you still have the LFE channel mixed into centre using a four pole jack.

  12. halfgaar

    I don’t use that card anymore, nor do I have such a cable. So I can’t test that for you. You can test it yourself easily. Play a film with only that plug connected.

    My point about the games, is that if everything is strictly correct, there will be no signal on LFE output for games. However, some soundcard panels do allow you to redirect bass to the .1 output, likely not doing -10dB to be spec-correct. Disable that bass redirection. If the bass management on your Onkyo works properly, the bass will be properly distributed to speakers plus a subwoofer, if present.

    In theory, you still need to apply the +10dB boost to the incoming LFE signal for sources that do have that channel, like films. But if you don’t play films using the analog outputs, never mind 🙂

  13. xixxixorx

    That is strong evidence of mixed channels.
    If you mix two 0dBfs signals, you would need 6dB attenuation before the mix to avoid clipping.

    You either have a defective unit (doubtful), or the Creative Drivers mix the channels.

    I’ve extensively used the A2ZS. The “Left” and “Right” of the C/LFE output aren’t mixed in any fashion. This can be demonstrated through the kX Project drivers. I promise, it’s two independent channels. I’m happy to bash Creative software over this, but the hardware doesn’t behave like this.

    It’s an 8-channel sound card.

  14. halfgaar

    I suspect that when using the proper 4 pole cable as described above, the center and LFE are separate channels. It would be like plugging a mono plug in a stereo output: you get both channels mixed.

    However, all the other objections stand.

© 2024 BigSmoke

Theme by Anders NorenUp ↑