Computer  Music
 
 

Information on MIDI music creation, editing, playback and the hardware / software involved.


FAQ  on  Computer  Music


Q. When I play a MIDI file, it sounds crappy. Why is this?

A. The most common cause is not using a wavetable card or wavetable
synthesizer software. If this is the case, you may be using FM voices.
FM voices are very inferior. If you have a wavetable sound card and
the MIDI file still sounds crappy, check your multimedia parameters in
your control panel. Go to your control panel and double-click on
Multimedia. After opening up its window, select the MIDI tab. Under
where its says Single Instrument, look for something have to do with
wavetable or "MIDI Mapper". Select one of these. If you have only
External MIDI OUT (assuming that you have no MIDI keyboard or
sound module) and FM Synth, then I'm afraid that you need to step up
to something better than what you have. A Sound Blaster AWE-64 or
a Sound Blaster Live is a good choice to upgrade to.  Please note that
even the Sound Blaster Live Value is a good choice for most musicians.
Q. When I play a MOD, WAV, MPEG-3, or a Real Audio file, a lot of
cutting in and out occurs. The sounds may have a lot of static.
What causes this?
 
A. A number of things can cause this. If it does it also with hardware
wavetable when playing a MIDI file, then you probably have a bad
connection somewhere. Check your cables or replace them. Radio
Shack cables and fittings tend to have a bad history of getting breaks
in them. Try your speakers with another device. If the speakers have
their own amplifier, try another line-level device, such a CD player,
tape deck, or the audio out from a VCR. If the problem does NOT
occur when playing MIDI files, then it is likely due to overloading the
CPU. If you have too many icons on your desktop and/or too many
shortcuts, you may have problems like this. Slower CPU's will have
more problems due to this.
 
Q. MIDI files sound better on my friend's PC than on mine and yet I have
a wavetable sound card. I thought that General MIDI was universal.
What is wrong?
A. Since sound data is not stored in MIDI files, it relies on the sounds on
the hardware that it is played on. Some wavetable sound cards have
better instrument samples than others. Some wavetable cards will
allow you to override the ROM samples with custom samples. This
is especially true with the Sound Blaster AWE series cards. In addition,
volume curves (for track volumes) are not entirely universal. This can
cause the mixture to sound different on different wavetable cards.
Q. When I am playing a Real Audio file, a lot of cutting out occurs. Why
is this?
A. You may have too strict of parameters given the baud rate that you are
running at. If you are running less than 28.8K baud or 33.6K baud, then
you may need to disable 16-bit output. Also check your buffer size.
While bigger buffers use more memory, it allows more stuff to be down-
loaded ahead of time so that cutting out is less likely to occur. Remember
that you are placing a horrendous load on the CPU, for it has to read the
stuff coming in from your modem, play back what is in a buffer, and
possibly do file decompression--all basically at the same time.
Q. When playing a CD in my CD-ROM drive, a lot of cutting in and out or
a lot of static occurs. What is causing this crap?
A.  This can be caused by a loose connection between your CD-ROM drive
and your sound card.  You might try opening up your PC and checking
the CD cable that runs from your CD-ROM drive to the sound card.
Be aware that if you open your PC, you may void its warranty (if it is still
under warranty). In addition, you need to take precautions against static
electricity. The easiest way to avoid hardware damage due to static is to hold
onto an unpainted part of the chassis with one hand while you check the
CD cable with the other hand. It may be possible that you may have to
temporary remove the sound card in order to get to this connector. By all
means, SHUT THE COMPUTER DOWN before getting inside of it! If you
take out or insert a card with the power on, you may do a couple thousand
dollars worth of damage faster than you can say "right now!"
     If you are using the digital route for CD playing, this can be caused by a
number of things.  One of these is too many icons on your desktop or too
many shortcuts in the system.  The most common problem is that the drive
itself is not calibrated accurately for digital CD output.  Also, some CD's
can be read digitally more easily than others.  Overloading the CPU can
cause this when playing CD's through the digital route.
Q. Since I don't have a wavetable soundcard, I like MOD files better than MIDI.
However, about 80-90 percent of the MOD files are punk rock. Why aren't
there many MOD files in other music styles?
A. You have a good question here. I guess that it's time to break out the pipe
organ and start playing "Toccata and Fugue!" You may at least ten times
happier getting yourself a wavetable sound card and get back into playing
MIDI files, for the variety is much greater.
Q. When I'm on the internet, my MIDI player either stops or cuts a song short
and goes onto the next. Why is this?
A. I have had this problem myself. According to my investigation, it is due to
the internet software trampling on some parameters used by the MIDI player.
Media Player is especially prone to this, along with causing system crashes.
Creative MIDI also seems to fall victim to this. MIDI Plus is a bit better.
Common offenders include either Dialup Networking or possibly CSi 3.0x and
Netscape 3.0.
Q. Since I can't tell if a MIDI file is General MIDI, MIDI GS, MIDI XG, or even
proprietary MIDI, does it hurt anything to try it on my player?
A. No crash or failure will occur due to this. The worst that you will have happen
is hearing wrong instruments or having instruments missing.
 
Q. When I play certain MIDI files on my system, notes often get cut off here and
there. However, it does not do it with all MIDI files. Is there something wrong
with these files?
 
A. This is generally caused by inadequate polyphony on your wavetable sound
card. While General MIDI calls for a minimum of 24 voices to be available,
elaborately written MIDI files can easily use 30-50 voices, or even more.
Pianos are probably the worst offenders due to their use of a sustain pedal.
A lot of polyphony is required for realistic sustains.
Q. Some MIDI files that I download will not play or they lock up the system. What
is causing this?
A. Four things can cause this. First of all, MIDI files written on a Macintosh
often have a special "header". This MAC header spells GRIEF for some players
and sequencers on other computer platforms. You might try finding a utility
that strips this header off. The second culprit is a bug in the sequencer that it
was recorded on. A buggy sequencer can write corrupted MIDI files. Another
culprit is too many tracks. Sometimes, musicians will add a bunch of "dummy"
tracks just so that they can contain more information about a song. Some
players will gripe about this. If this is the problem, try loading the song into a
sequencer capable of handling unlimited tracks and delete these dummy tracks.
If you are not sure whether if a track is a dummy track or not, try merging all
the tracks that go to the same channel together into one track and then delete
all the others that go to that same channel.
 
Q. Why do WAV files play but MIDI files stay silent or why does the CD player
remain silent?
A. You need to bring up an audio mixer. Go to the lower righthand corner of your
screen (for Windows 95/98) and DOUBLE-CLICK on the speaker icon. This
will bring up an audio mixer. Be sure that channels for WAV, MIDI, and CD
are not muted. Also, check their volume controls. Some sound cards have
their own audio mixer software that is more comprehensive then Microsoft's
built-in mixer. You may want to go to that one if you have it.
Q. When I play a WAV file, the volume is fine. However, when I play a CD or a
MIDI file, I can barely hear it. Why the sharp volume differences?
A. Go to the response for the question above this one. In addition, some MIDI
files are a lot louder than others. For a Sound Blaster AWE series card, try
setting the WAV volume to around 60-65 percent, the MIDI volume to about
75-80 percent, and the CD volume to 50-60 percent. This seems to yield the
happiest mediums.
Q. When I play a MIDI file or a WAV file, distortion sometimes occurs. I thought
it was all digital. Why the distortion?
A. The problem may be that you're overdriving your sound card. This is
particularly true with the Sound Blaster AWE-32. Try setting your MIDI
volume to no more than about 70% AND your master volume to no more than
around 70%. Try setting the WAV volume to around 50-60 percent. This
should clear up your problem. Also some people, INCLUDING SOME PC
BUILDERS connect self-powered speakers into the amplified output. This is
just asking for distortion and a slight chance of hardware damage. If this is
the case, GET THAT PLUG INTO THE LINE OUTPUT! The amplified
output is for AND ONLY for cheap PC speakers that have no power of their
own except for possibly bass boost.
 
Q. Since I don't have a wavetable sound card, I use a MIDI keyboard or sound
module for output. However, the output is TOTALLY scrambled or non-
existent, even though I have the MIDI preference in the multimedia control
panel set for external MIDI OUT. Why can't I get good stuff coming out?
 
A. One thing that can cause this is MIDI adapter incompatibility. Check with
the manufacturer of your sound card. Sound Blaster cards in particular have
these types of problems with some third-party MIDI adapters.
Q. When I use a MIDI keyboard or sound module for MIDI playback a note
"hangs" once and a while. Sometimes, a whole bunch of "sour notes" get
played. Why is this?
 
A. Unfortunately, you have come across the biggest drawback of MIDI itself--
its serial nature. There is no checking to see if the host successfully received
a MIDI byte. If even just one byte gets missed, the result can be hung notes,
NUMEROUS SOUR NOTES, and/or long periods of dead silence due to
subsequent mis-pairing of MIDI bytes. Some MIDI devices are better than
others. Even the best MIDI devices might miss 1-2 bytes a year.
Q. I have four keyboards daisy-chained through MIDI. Sometimes, it seems that
the system often "drags." Why is this?
A. Two things can cause this. Going from a MIDI THRU from one device to a
MIDI IN of another adds a small time delay. If you have four devices
connected this way, you may have a 30-40 millisecond delay on the last device
in the chain. You would benefit from either a MIDI "THRU-BOX" which is
a MIDI "splitter" or using more than one "MIDI bus". The latter solution can
be achieved through the use of two or more SEPARATELY ADDRESSABLE
MIDI OUT's. Another culprit is that you may be outdoing MIDI itself. If this
is the case, then you MUST go the way of multiple MIDI buses--using
SEPARATELY ADDRESSABLE MIDI OUT'S. Remember that besides note
data, there are pitch bends and possibly aftertouch--both of which can tax
MIDI heavily.
 
Q. I have a MIDI keyboard or sound module. How do I hook the MIDI adapter
up to it.
 
A. You asked a good question here. Believe it or not, you need to plug the cable
labeled THE OPPOSITE into the MIDI jack. For example, the plug labeled
"IN" needs to go into the jack labeled "OUT" and vise versa. Think as the
plug labeled "IN" as going INto the sound card. Likewise, think of the plug
labeled "OUT" as coming OUT from the sound card.
 
Q. I have a MIDI keyboard or sound module, but my MIDI adapter will not
reach it. What am I to do?
 
A. This is another very good question. Yes, the typical MIDI adapter is roughly
roughly three feet long--inadequate for some room arrangements. A few
will allow you to connect standard MIDI cables to them. However, most
are designed to plug directly into your keyboard or sound module, and this
is where the problem is. What you need is a 5-pin DIN female coupler.
To further complicate the mess, I have NEVER seen such a device anywhere.
One thing that HAS been proven to work are those standard computer key-
board (NOT PS/2) extension cables.  These are available at many electronics
stores.  Cables such as these typically give you an additional 3-6 feet.
If you are good with pinouts and soldering, you can make one using two
two MIDI jacks, sold at Radio Shack. While normal MIDI transmission
uses only pins #4 and #5, it is best to connect all of them, for there are a few
devices that use additional connections for power. However, DO NOT
just solder two DIN jacks back to back, or otherwise the pins will be
reversed. After making one described in the diagram below, wrap electrical
around EACH connection. Next bend the ears of the connectors to their
sides using pliers. Now wrap the whole thing in electrical tape so that it
looks a lot like the bottom picture. Using an ohm meter or continuity tester,
check to make sure that all corresponding connections are good, but not
contacting other connections, especially adjacent ones.

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