Understanding and mimicking Doom's sound design

One thing that bothers me about a lot of Doom mods is that most, if not nearly all mods containing new or replaced sounds just seem to rip them straight out of other games. People capable of creating their own sounds seems to be much rarer than creating new graphics or music.

I thought it might be useful to the community if I started designing new sounds as resources for other Doom modders, which can blend seamlessly with the existing vanilla sounds. First I really need to get under the skin of the original sounds though and get a real feel for what it is that makes them sound the way they do.
I've noticed that a lot of people trying to make lo-fi sounding samples for retro style games today just seem to run the sounds through a bitcrusher plugin and be done with it, which is just lazy and unimaginative and never truly captures the aspects of SFX from the 90's. There's a lot more to it than that.

All of Doom's sounds are in 11khz 16-bit as far as I'm aware. What's peculiar though is that some sounds, especially from monsters, seem to have a lot more aliasing baked into them than what's really necessary for that sample rate. Whether this is intentional or just a byproduct of the more simple editing tools Prince used is up for debate. Either way something like the Cacodemon death would not sound nearly the same if it weren't for all that aliasing.

Some of the sounds are also cut in a very sudden and rough manner, like DSPOSIT3 which sounds like it had the original, natural attack deleted.

DSITEMUP is a filtered square wave with a bit of noise in it.

I started "warming up" by creating some replacement sounds that try to be similar to the original sounds (except the creature sounds that just use zombies/imps as temporary placeholders). I've bundled both the loose files and a .wad so you can just listen to the wavs quickly or try them ingame. Haven't bothered converting the .wad sounds to the original format so be sure to use a sourceport that can handle .wav replacements.

https://dl.dropboxusercontent.com/u/66640537/doomsounds.zip

If anyone else has some insights on Doom's sounds then please share.

Lots of sounds from sound libraries.

^ This.

Stockmusic is your best friend for making Doom-style sound effects.

BTW Gecko, you should contribute some of your sounds to Freedoom, it really would help with the project. Some of the sounds in Freedoom are still kinda meh.

I know about the libraries like Sound Ideas they pulled from. Doom practically co-opted those stock sounds for itself. I'm not gonna use those because frankly they are overpriced and not worth the money compared to the modern high quality libraries available from newer independant stock sound companies.

I'd be happy to donate anything to Freedoom.

I'm not sure people are aware how much the low quality of a lot of the freedoom sounds contributes to the quality of the project. it'd be a massive boon to the project if a lot of the sounds were to be improved.

Unfortunately I'm very lazy when it comes to sound design myself, I have intended to learn better techniques for a while.

edit: could you give a quick rundown of how you are creating these sounds?

The shotgun is an M82A1 and FN FAL mixed together with the latter pitched down nearly an octave to give it a more explosive feel. I always have the original sound loaded as a reference to look at so I can sync timed events right like the reloading. The original Doom shotgun also has a quick dip in volume between the initial click and the tail, so I made sure to replicate that as well.

The zombie sounds are various cries, roars and growls (both human and animal) mixed together.

The lift is a large metal clank, a bass drum, a car window wiper, and for the moving sound some textile noise with some EQ automation, and the rising tone is some good old fashioned FM synthesis.

GeckoYamori said:

All of Doom's sounds are in 11khz 16-bit as far as I'm aware.

Some are 22khz, see full list here.

Interesting about the padding. I noticed those blips at the start and assumed it was just something funky with the converter since you never hear it ingame, and I guess I was right.

Here is the next batch of sounds. Explosions, doors, gibs, and a couple new monster sounds like Pinky. I noticed that some of the screams (particularly the player ones) have some kind of heavy intermodulation distortion (very different from harmonic distortion that you get most of from clipping) permeating the whole sounds, so I have to figure out how to replicate that somehow.

I used a fan sound and a siren to mimic the whiney part of the original door sounds.

https://dl.dropboxusercontent.com/u/66640537/doomsounds2.zip