phil@eos.UUCP (Phil Stone) (03/14/89)
We are looking into a replacement for a roomful of MassComp metal to be used for psychoacoustic experiments. I am very intrigued by the NeXT and its built-in DSP chip, but am afraid it may have a serious limitation that will make it useless for our needs. From what I have heard so far, the highest sampling rate supported (without additional hardware - we need this now, not 7 months from now!) is 44Khz. Since most of the work in this field uses 50khz data, this could be a big problem. Can anybody confirm or debunk this? Excuse me if this is old news, but I've just started to look seriously at the NeXT in the last week or so. Phil Stone (phil@eos.arc.nasa.gov / ames!eos!phil)
linden%adapt@Sun.COM (Peter van der Linden) (03/14/89)
> Phil Stone enquires about the NeXT DSP sampling rate
Looking back through the notes I made at the time of the
launch, I find that the DSP chip handles two channels of
16-bit data sampled at 44.1 kHz.
Peter. no witty remarks today (except this).
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Peter "big-hearted" van der Linden linden@sun.com (415) 336-6206
Worshipper of Bacchus in Naur Form.ali@polya.Stanford.EDU (Ali T. Ozer) (03/15/89)
In article <2884@eos.UUCP> phil@eos.UUCP (Phil Stone) writes: > ... From what I have heard so far, >the highest sampling rate supported (without additional hardware - we need >this now, not 7 months from now!) is 44Khz. Since most of the work in this >field uses 50khz data, this could be a big problem. Metaresearch, Inc has a box that will send 16 bit samples to the DSP port on the cube. The box, named "Digital Ears," can apparently sample at 44.1kHz in stereo or 88.2kHz in mono. I hope this will be enough for what you want to do. Availability is "March 1989." For more info contact: Metaresearch Inc, 516SE Morrison Suite M-1, Portland, OR 97214 I don't know any more about this box; please contact the above address for details. Ali Ozer
jasmerb@mist.cs.orst.edu (Bryce Jasmer) (03/15/89)
I found this at the anonymous ftp site at Oregon State University
(cs.orst.edu in the directory ~ftp/pub/next/announcements):
------------------------------------------------------------------
NeXT IS PLEASED TO ANNOUNCE THE FIRST 3RD PARTY HARDWARE PRODUCT
PRODUCT NAME: Digital Ears
MODEL: Audio Input Device DE-1
OVERVIEW
The Digital Ears(TM) audio input device provides the means to record
compact disk quality sound on the NeXT(TM) computer. The DE-1 accepts
stereo line input form any source, including CD players, tape decks and
studio mixing consoles. In addition, DE-1 can quantize laboratory
signals down to DC, allowing for high precision measurements. Signals
are converted to true compact disk format, 16 bit, 44.1 kHz stereo.
This information is then sent to the Digital Signal Processor (DSP)
port on the NeXT computer. The DE-1 is a stand-alone device, drawing
its power from the DSP port.
APPLICATIONS
The Digital Ears device is suitable for creating disk sound files in
standard NeXT format. These sounds files can be used within
developers' applications. Example applications are:
o Low cost, high quality digital recording studio
o Voice and speech analysis
o Inclusion of sound in application interfaces
o Quantization of laboratory data (DC mode)
o Harmonic and signal analysis
FEATURES
o True CD quality format (16 bit, 44.1 kHz stereo)
o Deposits sound information onto disk via the DSP
o Draws power form the DSP port
o Self-calibrating A/D converter
o Stereophonic and monaural recording modes
o Input level gain adjust for each channel
o accurate DC response in DC mode
OPERATING MODES
o Stereo/Monaural: The DE-1 can act as either a stereo or monaural
recording device. If used in monaural mode, over-sampling occurs at
double stereo rate.
o AC/DC: Determines whether to input either AC (audio) or DC signals
into the NeXT. The mode is selected with an internal jumper.
o Variable Input Gain: 0 to 10X, independent channel adjustments.
TECHNICAL SPECIFICATIONS
Frequency Response DC-19 kHz (-3db)
Sampling Rate (stereo) 44.1 kHz
Signal to Noise Ratio +98db
Total Harmonic Distortion -90db
A/D Input Voltage Range +/-5.0 V
Input Impedance 100k Ohms
Gain Stage Noise Equivalent 24 nV/Hz, @10Hz
8 nV/Hz, >1kHz
Linearity Error (DC mode) +/- LSB (4 parts in 65,000)
ORDERING INFORMATION
The Digital Ears package, order number DE-1 includes:
o Digital Ears audio input device
o DSP connector cable
o Input level adjustment screwdriver
o User manual
SUPPLIER
Metaresearch, Incorporated
516 SE Morrison
Portland, Oregon 97214
(503) 238-5728
Contacts: Kim Orumchian or Lee Buhler
COST: $825.00
Digital Ears and DE-1 are trademarks of Metaresearch, Incorporated. NeXT
is a registered trademark of NeXT, Incorporated.
------------------------------------------------------------------------------
Bryce Jasmer
jasmerb@hobbes.cs.orst.edu