Reply by Howard Long March 7, 20062006-03-07
"HelpmaBoab" <FU2@yahoo.co.zpc> wrote in message 
news:ph6Pf.4437$JZ1.96604@news.xtra.co.nz...
> Are you saying that a SB has a fixed anti-aliasing filter at 20kHz even > you > you sample at say 22050Hz? Surely not. > I understood they used over-sampling and down-sampling.
If I record from, say, an SB Audigy 2 (or most other cards) at a sampling rate of 96kHz, the passband still tails off rapidly at about 20kHz. Whether this is a front-end analog low pass filter, the codec's digital anti-aliasing filter or the way the codec is configured at the driver level (or a combination of the above) I don't know. A similar thing happens on playback. The only cards I am aware of that don't are the m-audio cards, although there may be others. Regards, Howard
Reply by HelpmaBoab March 6, 20062006-03-06
"Howard Long" <howard@howardlongxxx.com> wrote in message
news:duib8u$o0p$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
> "HelpmaBoab" <FU2@yahoo.co.zpc> wrote in message > news:3tNOf.4215$JZ1.85235@news.xtra.co.nz... > > Are there any sounds cards that have 4 inputs that are synchronised? > > > > Thanks > > > > Tom > > Try www.m-audio.com. Their drivers specifically have that a sync option in > their control panel applet. I believe you can sync more than one card if > necessary. > > I have their Delta 66 and Audiophile 192 and both have awesome audio
specs,
> making the high-end sound blasters look positively kindergarten material. > For example the anti aliasing filters of the m-audio devices only start > kicking in close Fs/2, unlike the sound blasters that always start kicking > in at 20kHz regardless of Fs. > > Regards, Howard > >
Are you saying that a SB has a fixed anti-aliasing filter at 20kHz even you you sample at say 22050Hz? Surely not. I understood they used over-sampling and down-sampling. Tam
Reply by Howard Long March 6, 20062006-03-06
"HelpmaBoab" <FU2@yahoo.co.zpc> wrote in message 
news:3tNOf.4215$JZ1.85235@news.xtra.co.nz...
> Are there any sounds cards that have 4 inputs that are synchronised? > > Thanks > > Tom
Try www.m-audio.com. Their drivers specifically have that a sync option in their control panel applet. I believe you can sync more than one card if necessary. I have their Delta 66 and Audiophile 192 and both have awesome audio specs, making the high-end sound blasters look positively kindergarten material. For example the anti aliasing filters of the m-audio devices only start kicking in close Fs/2, unlike the sound blasters that always start kicking in at 20kHz regardless of Fs. Regards, Howard
Reply by Richard Dobson March 6, 20062006-03-06
HelpmaBoab wrote:
> Are there any sounds cards that have 4 inputs that are synchronised? > > Thanks > > Tom > >
Any card that provides a single "multi-channel interleaved" device will run all the i/o of that device under a single clock, so that the channels are sample-aligned. The M-Audio family all support this, for example. Under Windows, the host software will need to open the device using the WAVEFORMATEXTENSIBLE format; last I heard, Matlab has not yet been updated to do this, but pretty much all modern audio applications know about it. Some cards such as the SounBlaster Audigy series only support this under DirectSound. On the Mac, CoreAudio supports multi-channel as standard. Cards with 4-channel analogue inputs tend to be high-end pro-audio rather than consumer-level. The alternative is any of the cards that offer ADAT digital i/o (8-channel), combined with an external converter (e.g. the Hammerfall series, which have drivers for Linux as well the Windows and Mac). High-end pro-Audio cards also offer an external word-clock connection, so that all digital devices in a studio can be synchronised to a single master clock. Richard Dobson
Reply by Ze Ji March 6, 20062006-03-06
Yes, like Maya II, which we bought for the cheaper price.

Synchronised? Not really. But to install ASIO driver, the delay can be
minimised to be an acceptable level. However, matlab does not recognise
ASIO driver, that means in Matlab, you can only use two channels at the
same time.

I guess, most of the sound cards with four inputs are designed in this
way.

But, anyway, if you find any sound card that can be sunchronised, let
me as well please. :-)

Reply by HelpmaBoab March 5, 20062006-03-05
Are there any sounds cards that have 4 inputs that are synchronised?

Thanks

Tom