[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[linrad] Re: 96000 Hz sampling on laptop

Hi, Jeffrey,

I have more to add based on your interesting posts. I think you have opened a whole new avenue here.

After getting your first email I went right away to the other immediately available XP machine I have here [another two are at my remote site so I can't test them right now]. This is a Dell P4 that shipped 4/6/2005 and that according to its user manual uses an ADI 1980 [AC97 Codec] for onboard sound [SoundMAX Digital Audio]. That chip is rated for sampling from 7 to 96 kHz. I would have thought that a machine shipped then would perhaps have used Intel High Definition Audio rather than the AC97 standard, but apparently not. The AC97 standard permits sampling to 96 kHz, where as HD Audio allows up to 192 kHz I believe.

As you would have predicted, with this computer I can play back the 96 kHz [and ALSO the 192 kHz sampling-rate] files that I made on the laptop with no problem. I can also RECORD 192 kHz sampling-rate files using Cool96, so either I am wrong about the SoundMAX being limited to 96 kHz, or XP is also able to do rate conversion on the fly when recording as well as when playing back files. I do not have the knowledge / capability of tearing apart the wave files I have generated on the laptop or this machine to check on any interpolation done to get to 192 kHz sampling when recording with each of the systems and thereby figure out if the soundchip is really sampling at 192 kHz or if the operating system is just interpolating. Also, both Linrad and Winrad do fine playing the leon2001.wav file back using the SoundMAX for both input and output at 96000 Hz, though that doesn't prove anything new since this chip is rated at 96000 Hz.

So, this is a SECOND garden-variety computer with a SECOND on-board sound chip from a different manufacturer [AD1980] that is also rated at 96000 Hz and works fine with Linrad for Windows and Winrad. And the OnBoard sound on this computer DOES have a stereo line input, so this machine could be used for Linrad or Winrad with an external signal source rather than just a wave file, without needing to add a sound card.

I agree absolutely with your comments regarding the QUALITY that one would expect to get using OnBoard sound for this purpose. I am sure that the dynamic range, SNR, etc are below what one would find with the Delta44, for example. But for getting started, now one can play with Linrad and Winrad and not have to invest in a Delta44 right off the bat just to get a rough feel for things.

I tried to find some 'real for-sure actual' 192 kHz sampling rate wave files on the web to use as test objects [by checking out some high end audio sites, by 'Google', etc, but wasn't able to find anything. I am sure these files are out there, I just wasn't able to find them.

Thanks again for opening up a new and very interesting avenue here. It really makes it worthwhile to update the OS to 2000 or XP. I should note that one of my computers at the remote site, a 1.8 GHz Dell, had some arcane but major [to me] sound issues under 2000 that wouldn't go away, and so I decided to upgrade to XP and everything is fine with it now.


Roger Rehr

On Sun, 12 Mar 2006 15:10:55 -0500, Jeffrey Pawlan <jpawlan@xxxxxxxxxx> wrote:

I believe I have the answer to Roger and others why the 96KHz wav files are
played by the old laptop with an ESS chip.

Under Win2000 and also XP the supported sampling rates of the soundcard or chip is expanded by conversion within windows. In Win98 this is not the case. I just tried this experiment with a 2 channel 96KHz wav file on the very same computer that has dual boot. Under 2000, the old Turtle Beach card plays the 96KHz file even though I know absolutely for sure that the card itself can't possibly use a 96KHz setting. But under 98 there is an error message whe I try to play the
file, and it says "this wave file is not supported on this sound card."

So practically any older laptop might be able to play the 96KHz files
provided it is running 2000 or XP. The card or chip is only going up to its true limit which is likely 48KHz. You will see this if you try to record, sampling
at that high rate when you input a signal to the mic or line input.


Jeffrey Pawlan  WA6KBL

Roger Rehr

This message is sent to you because you are subscribed to
 the mailing list <linrad@xxxxxxxxxxxxxxxxxxxxx>.
To unsubscribe, E-mail to: <linrad-off@xxxxxxxxxxxxxxxxxxxxx>
To switch to the DIGEST mode, E-mail to <linrad-digest@xxxxxxxxxxxxxxxxxxxxx>
To switch to the INDEX mode, E-mail to <linrad-index@xxxxxxxxxxxxxxxxxxxxx>
Send administrative queries to  <linrad-request@xxxxxxxxxxxxxxxxxxxxx>