navigation bar

WWW Digital Function Generator

It is imperative that you read the text below before clicking on the "Proceed" button. The text outlines important information on WWW Digital Function Generator requirements and safety. Adult supervision is required for persons under the age of 18.


Computer
  • You require a PC running Win95 / 98 / Me / NT / 2000 / XP / Linux, SUN - Solaris, or a Macintosh running OS 8, 9 or X.
  • Microsoft Explorer 4x (or higher) or Netscape 4x (or higher).
  • The latest version of the Java plug-in from SUN (most newer PC's come with this version of Java plug-in already installed).
  • A good-quality sound card.
  • All applications on your computer, except your web browser, must be closed.
  • All sound-processing features on your sound card such as "Bass Boost", tone control, reverbaration, DSP, etc. must be disabled.
  • The volume on your computer and/or audio system must be at the level you usually use or lower. You can lower volume by going to volume adjustment in the Mixer software. In Windows this is done by selecting Start -> Programs -> Accessories -> Entertainment -> Volume Control. Check your computer manual for other platforms.
Java Plug-in & System Test
  • When you click on the "Proceed" button located further down the page a simple application called "System Test" will be launched. The application will test your computer system for compatibility with our software. It will also determine whether you require a Java plug-in.
  • If you require a Java plug-in, follow the instructions to download it. If no automatic install takes place make sure to double-click on the downloaded .exe file to install it.
  • Make sure that Java version 1.4.1_02 or higher is used during testing (multiple Java environments may co-exist on your computer).
Headphones
  • Should be of good quality (for example AKG K-270 or KOSS R/80).
  • Closed-type headphones are the best choice as they reduce outside noise.
  • Headphones must be plugged into the headphones output on your computer. The headphones output is usually marked as such and it is most often located on the back pannel of the computer. In most cases, it is a miniature stereo output, similar to the output socket on a portable CD player. If necessary, refer to your computer manual for more details.
Earphones
  • Should be of good quality (for example some models of SONY, Panasonic, JVC, AKG, KOSS).
  • Miniature earphones (or earbuds) can be turned into good-quality "closed-type headphones" by wearing earmuffs over them. Good earmuffs (for example Thunder 29 from Howard Leight) offer about 29-31 dB noise reduction (better than most headphones). You can buy them in many hardware stores for about $20 US. Earmuffs can also be used to protect your hearing in noisy situations.
  • Earphones must be plugged into the headphones output on your computer (as described above).
Speakers
  • Should be of good quality (for example ALESIS 'Monitor One Mk2' or 'M1 Active Mk2').
  • Good quality speakers will have flat frequency response in 40 Hz - 20,000 Hz range and low harmonic and intermodulation distortions.
  • Speakers must be connected to the power amplifier. Amplifier should get its signal from line (or headphones) output on your computer. They are usually marked as such and most often located on the back pannel of the computer. In most cases, it is a miniature stereo output, similar to the output socket on a portable CD player. In some cases there are RCA-type connectors on the soundcard. If necessary, refer to your computer manual for more details.
Noise
  • For auditory and psychoacoustic experiments, all noisy equipment (such as fans, radios, etc.) must be switched OFF to minimize background noise that can interfere with the tests.
  • You should perform the tests when the noise level in the room and outside is at its lowest.
Safe Sound Levels / Calibration
  • DFG modules can be used in a variety of very interesting acoustical, audio, auditory, psycho- acoustic and electronic experiments. However, caution is required in the adjustment of safe sound levels to protect your hearing and audio equipment.
  • SPL (Sound Pressure Level) should be limited to maximum 80 dB SPL for several minutes of exposure and to maximum 60 dB SPL for several hours of exposure.
  • Sound calibration should be performed with a properly working SLM (Sound Level Meter). Volume calibration can be performed by using volume control in the computer Mixer software or externally on the powered speakers or amplifier.
  • For calibration of headphones or earphones one needs SLM (for example from Radio Shack) and acoustical coupler (such as DR1, DR2, or DR1-R from Digital Recordings).
  • Warble Tone Generator (one of the DFG modules) should be used for most accurate calibration. Calibration should be performed at 1000 Hz and 0 dB setting of the DFG module. SPL should be set to 60 dB, 70 dB or 80 dB (maximum for short durations) with the aid of SLM (Sound Level Meter) and proper acoustical coupler (for headphones and earphones).
Hearing Protection
  • For audio and acoustical experiments involving sounds produced by speakers at levels higher than 60 dB hearing protectors such as earmuffs (for example 'Thunder 29' from Howard Leight) or earplugs (for example 'Classic' from EAR) should be used.
  • Hearing protectors have only limited attenuation capabilities (usualy 10 to 30 dB depending on the used frequency and the type of the protector). Therefore, caution should be used. SPL levels in the ear after attenuation should not be higher than 80 dB for short duration and 60 dB for longer duration.
  • If at any time during the experiment you feel any discomfort, you should stop the experiment immediately and switch OFF the sound source.
Safety
  • Volume calibration is the first step in any acoustical, audio and auditory testing and experiments. You must follow the provided instructions to set safe sound levels in order to protect your hearing and your computer/audio equipment.
  • if at any time during the testing or experiments you feel any discomfort or you find volume levels too high switch OFF the sound source and stop the test immediately.
  • Volume Calibration should be performed with the aid of SLM (Sound Level Meter) and proper acoustical coupler (for headphones and earphones). Please see our website for more information about acoustical couplers (DR1, DR2 and DR1-R).
Copyrights / License
  • All sounds produced by DFG modules are licensed by Digital Recordings for your personal, environmentally-responsible and non-commercial use only.
  • Reproduction, duplication or public use or broadcasting of DFG sounds is strictly prohibited.
  • Recording, editing, reuse, reformatting, resynthesizing, remixing, filtering or any other type of processing for use in another product or for resale is strictly prohibited without written license and permission from Digital Recordings.
  • Commercial use and resale of DFG products and sounds produced by DFG package is strictly prohibited without written license and permission from Digital Recordings.



The System Test application as well as the WWW Digital Function Generator will be launched in a separate browser window. You can, therefore, return to this page at any time during the test.

Your Feedback !

Please send us your comments regarding the WWW Digital Function Generator. Tell us what you liked, what you did not like, what difficulties, if any, you have experienced. Your feedback will be greatly appreciated !

About Us | Products | Services | Publications | Opinions | Contact Us

Copyright (C) 1990-2003 by Digital Recordings. All Rights Reserved.
No part of the information provided on this www page may be reproduced for any purpose, in any form, without prior written approval.