Short: Tests the frequency response of speakers UpLoader: Daniel Westerberg (daniel / onyxsoft se) Author: Daniel Westerberg Version: 1.0 Type: mus/misc Requires: AmigaOS 4.0+, MUI Architecture: ppc-amigaos >= 4.0.0 About Speaker Range Tester ~~~~~~~~~~~~~~~~~~~~~~~~~~ This program is designed for testing the frequency response of a speaker or any other audio equipment such as filters, amplifiers, etc. It works by sending out (playing) sinus waves at one frequency at a time and then meassure the input magnitude from for example a microphone for each frequency. When it has tested a specified range it will stop and draw a graph or diagram with deciBell versus frequency to let you see and analyse the frequency response curve. News and Changes ~~~~~~~~~~~~~~~~ * First release. Requirements ~~~~~~~~~~~~ - The program uses MUI and requires Lamp.mcc. - To play and record, AHI is used. - A full duplex sound card (and AHI driver), or two individual sound cards are needed. - A microphone if you are going to test speakers. Mini Usage Guide ~~~~~~~~~~~~~~~~ Setup: 1. Set up your microphone, or other equipment to test. 2. Start the program. 3. Go to the Settings page and choose your AHI device you plan on using for playing and the one you have configured for your microphone (or other input equipment) as input unit. 4. Go to the page Manual Experimentation. 5. Click on Player to start playing a test tone to make sure the AHI unit is configured correctly. 6. Slide the knob just below "Frequency:" to change the test tone. 7. Start the recorder by clicking on the Recorder button. 8. Watch the input level and see that it reacts to the microphone if that is what you have connected. The input level should show a green light, or possibly yellow. This indicates the level is good. Blue means the level is too weak, red means it is too strong. 9. When the level is ok for most frequencies (test with the frequency slider) it is time for the real test. The test: 10. Enter a lowest frequency for the test. The default 20Hz is considered the absolute lowest bass frequency a human can hear. It is also the goal frequency of a HiFi speaker. Very few speakers can play this low though (within their -3dB range). NOTE: It may be wise to select a higher frequency if you have a subwoofer that you know can't handle this low frequency and may blow! 11. Select the highest frequency to test. The default 20kHz (20000Hz) is considered the highest trebble frequency a human can hear, although most adults can't hear above 15-16kHz. 12. Select the test resolution. High is usually sufficient for a good reading. "Full" tests 100 frequencies per octave. (One octave is the doubling of the frequency from f.ex. 100 to 200Hz or from 200 to 400Hz.) "High" tests each musical halv note per octave. There are 12 half notes per octave. "Medium" tests 4 notes per octave. "Low" tests 2 notes per octave. 13. Passes/frequency is how many AHI buffers should be played and recorded for each frequency. Each pass is 1/50th of a second. More passes gives a better average reading for each frequency. Finally: 14. If you are testing a speaker with a microphone, make sure the room is as quiet as possible to prevent ambient noise from giving incorrect results. Constant ambient noise from for example a computer is quite ok, but sudden noises such as someone speaking or a squeeking chair will give fake peaks in the reading. 15. Click the Start button and let the program play its tones. It will take a few seconds. After the test completes a graph will open and show you the result. Have fun! :-) Drop me a mail if you have any questions. Future ~~~~~~ * Possibility to load a reference curve to use for compensation of non-linear equipment. * Possibility to view many curves at the same time. * Self-adjusting output volume and input gain. * Saving of sampled input wave data. * Write a better Guide documentation. * Release versions for OS3 and MOS. -- Other programs by Deniil 715! can be found on OnyxSoft homepage at: http://www.onyxsoft.se/ Feel free to mail me if you found bugs or have suggestions: daniel / onyxsoft se NOTE: Please, NEVER publish my e-mail, or a text file containing my e-mail, on a web page or similar unless spam-encrypted like above. Thankyou.