Troubleshooting Recording

The following file is adapted from a message sent to the SigList by the author of Signalyze, Eric Keller, dated April 25, 1996.

Here's a general guide on understanding potential difficulties with recording, particularly with recent machines:

(1) Please forget about using any of the recording options in the Macro>Record Setup... dialog, except "Apple Sound Input Device". The Digidesign option is no longer operational on recent machines and recent versions of the System, for example, nor is the MacRecorder option. This is due to recent or not-so-recent changes in the hardware (roughly 1992-present). These incompatibilities are incontrovertible, and as already announced, future versions of Signalyze will have a simplified record setup dialog from which these "historic options" will be removed. Only "Apple Sound Input Device" will remain.

(2) Perform the following steps to find out if your Mac records at all.

a. To help you along, select "Show Balloons" under the Help ("?") menu in the Mac's main menu bar.

b. First check if you have set the correct input settings. In the Sound Control Panel (OS 8, Sound & Monitors) do the following:

The exact appearance of the Sound Panel has changed somewhat over different versions of the Mac OS, but basically, you should select the right input source (typically microphone) through the Sound Panel's input options. Once that has been done, verify your settings by recording a sound via the Sound Control Panel (not via Signalyze). You can do that by pressing the "Add" button in the "Alert Sounds" portion of the panel, and by manipulating the record and playback buttons found in the small record dialog.

c. If you cannot record through the Sound Control Panel, check your input device, your amplification, and your connections. Please remember that 16-bit input devices may require amplified input. Amplified mics, like the Apple PowerTalk mic, have longer mini-plugs. Adapters are also available from Griffin Technology, that will allow the use of any inexpensive, non-amplified mic to either the microphone jack or a USB port.

d. If you cannot find any problems with the input device, its amplification or its connection, you have an honest-to-goodness hardware fault. It is surprising how often that occurs: quite a few Signalyze users have reported such faults. You're now in for a trip to your Apple dealer before you can test recording with Signalyze.

(3) Once you have established that you can indeed record via the Sound Control Panel, you're ready to test if you can record with Signalyze. Perform the following operations:

a. In Signalyze, select Macro>Record Setup. In this dialog, select "Apple Sound Input Device". Select the recording frequency (typically as low as possible to save signal space). Deselect "As long as possible". Specify "1" as the number of seconds you want to record. Exit with "Save".

b. Verify through the Apple>About Signalyze dialog that you have enough signal memory available. If not, follow instructions in the Manual and in the handy memory setup guide to give you more signal memory.

c. Now (finally) do Macro>Record Signal. If you've safely got to this point, 99.5% of the time you should have no difficulties recording. The Signalyze record facility has been kept to its strictest minimum in order to keep you out of trouble and to assure the greatest compatibility across machines. This is the reason that you cannot interrupt recording, and that you don't see any pretty progress bar. These enhancements would have added further complexity, and would probably have resulted in a disproportional number of incompatibilities on various machines.

d. If you now have a recording problem, try one more thing: Reboot with the extensions off and run Signalyze all alone. You suppress the loading of all extensions by keeping the Shift key pressed while the machine is starting up. Sometimes you may have an extension that interferes with the recording process, or even more often, you may have another application that has temporarily taken possession of your input channel and has left no channel for use by Signalyze.

(4) NOW, if you STILL have a recording problem, please contact Linguist Plus support and we will try to establish exactly why and where Signalyze gives up on you. So please describe in some detail:

on which machine you are running
what input device you've good hooked up to it
what version of the System you are using
how far you get with the above steps
and what happens when you get stopped in your attempts to record.

We will do what we can to help you. But please understand that Linguist Plus does not have access to the many models of Mac that exist out there now. At the present, Signalyze testing is being done on the following machines: a Mac IIsi, a Performa 520, a 7100 66/AV (with and without a G3 update card), a G3 333 PB, a G3 266DT, and G4 450.

disable VM, if enabled

Note: Any software solution--RAM Doubler, or Virtual Memory--probably should not be used to record long stretches of signals where fine-detail measurements will be desired. All memory juggling utilities may cause some samples to be lost, especially at higher sampling rates, resulting in degraded signal information.

In particular, Virtual Memory is highly suspect in the pops and clicks introduced into signals sampled with the standard Mac sound input, especially in the first generation (6100, 7100, 8100) PowerMacs. An Apple Tech note stated that Virtual Memory should be off during recording.

I have never observed any sampling loss with RAM Doubler or RAM Charger, and a RAM Charger representative told me that RAM Charger is doing nothing that would interfere with system operations (and hence presumably recording) but it is worth checking your signals for any evidence of missing samples--clicks, pops, obvious discontinuities that don't sound like the usual speech noise, etc.