Spectrum Computing

I've always assumed that all Speccy models are mono. Sure, I've seen YouTube videos with stereo audio, but I figured they're just emulator 'fakes'.

Recently, though, read a comment (forgotten where) suggesting that some models may have stereo output? Is this true? If so, how are the AY channels split?

@Lee Bee,

https://www.bytedelight.com/?product=st ... 128k-model

Officially, no, they're all mono. There are various ABC or ACB mods for the 128 models which put B or C centrally respectively, with the other channels exclusively left or right. The lack of any kind of standard there means it's unlikely very much was ever written specifically for a given arrangement, short of a few demos written by someone who had a specific mod maybe. Even on the Amstrad CPC, which had an official ABC stereo arrangement, this was hardly ever taken into consideration (probably because the original machines only had a mono speaker output built it).

Basically, "no", then. Thanks for the answer guys!

There have also been various expansion/interface cards that add a AY sound chip or other sound chip. Some of these have a stereo output.

Mark

Official models don't have that OOTB, but for unofficial ones this is pretty much the norm, and still is I think. Most popular schemes are ABC and ACB, sometimes BAC but very rare. It was considered good practice BITD to provide a setting to switch between some of these (ABC/ACB/BAC) in ezines/new games/trackers and the like. YMMW what to do with this information today, and most of the time this likely doesn't change a lot to begin with. Personally though, I would avoid doing some clearly less-than-smart things, like fx players that 'choose the least loaded channel', or multi-channel effects that just assume mono output - that's gonna sound like ass on stereo (and likely youtube as well by extension).

Nienn Heskil wrote: ↑Mon May 01, 2023 9:25 am Personally though, I would avoid doing some clearly less-than-smart things, like fx players that 'choose the least loaded channel', or multi-channel effects that just assume mono output - that's gonna sound like ass on stereo (and likely youtube as well by extension).

Ah yes… THAT'S where this issue was raised - by you in my recent thread about SFX!

As a musician (working on a few games at the moment), this is an issue I wanted to consider. Though I think I've come to the personal conclusion to ignore stereo. Let me give my reasoning…

The vast majority of Spectrum games are most definitely optimised for mono. Listening to those games in stereo may sound cool, but technically it 'breaks' the music because the channels are designed to be blended together as one, not separated out. There are many effects which don't sound the same with the channels separated out, not to mention haphazard panning. It may sound good but it's not an authentic listening experience.

And I doubt there could be many games (classic or modern) which deliberately attempt to keep SFX in the 'center channel' - I'd imagine that the SFX in most games would randomly jump all over the place on a stereo machine. Totally unacceptable.

Plus, even if we wanted to design for stereo, there isn't even an official "center" channel! Like you said, some stereo models have channel B in the center, while others have C in the center. If there were a universal 'standard', I'd be inclined to take stereo a lot more seriously - in fact, I might embrace it wholeheartedly. But there isn't a standard. If I optimised for ABC, listeners with ACB would have a bad listening experience.

Incidentally, does anyone know roughly what ratio there is of Spectrum owners listening with ABC stereo vs ACB?

Also keep in mind that really for the best stereo, you should have two AY chips. One for the left channel and one for the right channel…

I can’t answer which is most common, ABC or ACB. But I believe the proportion varies between different countries. In the U.K. ABC may be more common than ACB. So the best way is to have the software configurable so select mono/ABC/ACB.

Mark

Are there any dual AY mods available for the Spectrum? I have dual SID’s and POKEY’s but never saw a Spectrum version.

This might come across as quite a tangent, but it's an insight I was given by a professional sound editor a few years back. He does know his stuff, his work on Game Of Thrones has won him a few Emmy Awards.

I was told that the public don't like to have sound coming strongly from either left or right in TV and film for anything that's live action, it's best to keep everything largely in the centre. The rule break to this is in animation - whether cel-based, Pixar-esque CGI or stop-motion. We unconsciously accept extreme lefts and rights in the sound for anything animated, but not with live action. It's all been tested by the movie studios, apparently.

Maybe that's something for game designers to consider? I never really thought about it until this guy learnt I was a video editor and gave me a few tips of the trade (ironically, while he was setting up a PA for a comedy night I had organised at a local pub).

Perhaps there's something in it, the stereo versions of Beatles records annoy me with the extreme lefts and rights, it's like the producers thought this new way of doing sound would truly showcase the abilities, without realising that 'less is more'.

PeteProdge wrote: ↑Mon May 01, 2023 1:12 pm I was told that the public don't like to have sound coming strongly from either left or right in TV and film for anything that's live action, it's best to keep everything largely in the centre. The rule break to this is in animation…

I have no experience with audio for animation so that's a new one to me. But, yes, generally sound always MUST be central. For example in film and TV you will almost never hear any dialogue anywhere other than dead centre, it just doesn't happen. Same for vocals in music. The stereo channels are generally there for soundscape and ambience, not for anything you're concentrating on. That's why I don't think a stereo Spectrum is a good idea because all the SFX in a game absolutely needs to be in the centre channel, but with most AY games, it likely won't be.

Lee Bee wrote: ↑Mon May 01, 2023 1:38 pm I have no experience with audio for animation so that's a new one to me. But, yes, generally sound always MUST be central. For example in film and TV you will almost never hear any dialogue anywhere other than dead centre, it just doesn't happen. Same for vocals in music. The stereo channels are generally there for soundscape and ambience, not for anything you're concentrating on. That's why I don't think a stereo Spectrum is a good idea because all the SFX in a game absolutely needs to be in the centre channel, but with most AY games, it likely won't be.

If it were possible on the Spectrum, it'd be nice to have extreme lefts and rights for anything menacing coming from those areas. It'd work in the likes of Bubble Bobble, New Zealand Story, Rainbow Islands, etc - the cartoony games of course, which definitely fit in the 'animation' remit.

Just to clarify, I don't think stereo Spectrum models are a good idea because:

1. When you create music in stereo, it needs to have all the parts in the correct stereo position, normally with the main melody, bassline and drums all dead centre, and the side channels balanced out. So if an AY tune has been designed for stereo and the channels get switched, it will ruin the presentation and sound off-balance.
2. AY sound effects likely won't be central. I've never worked in game audio and could be wrong about this, but I have a background in sound all my instincts say that all the SFX in a game (with a few rare exceptions) should almost always be dead center. Could be wrong but instinctively I don't feel that the 'animation' rule would apply to games. Don't ask me why!

One thing I haven't seen yet on ZX is a game with real stereo panning, i.e.taking objects positions into account. Use both left/right channels to play back the fx with simulated panning (different volumes), central channel for 'system' and/or player fx that need to be centered. Idk if this would make sense in 2d games (scrolling - yes, flip-screen - ... depends), but it definitely would in 3d ones, i.e. first-person action and the like. Of course, this leaves no channels for music, buuut subjectively, seeing the way AY music is in most ZX games*, it could be even better that way.

* I'm generally not a fan of the common 'repeating tune that plays non-stop all the time' style - the sound of the AY is simply not interesting enough for this to work. There are exceptions to this, like Sword of Ianna, but most of the time - just no. xd

In the 1980's, it wasn't an issue of the computer being mono speaker - TV's were mono as were the majority of consumer music players. Most TV's were under 30" so stereo wasn't seen as an importance.
I didn't experience surround sound until 1991 - a neighbour had a 4 speaker system and was keen to show it off. I can,t remember what he put on but I can remember the headache that set in after a few minutes.

Nienn Heskil wrote: ↑Mon May 01, 2023 3:16 pm One thing I haven't seen yet on ZX is a game with real stereo panning, i.e.taking objects positions into account. Use both left/right channels to play back the fx with simulated panning (different volumes), central channel for 'system' and/or player fx that need to be centered.

The first and only Javascript game I made was a Sokoban where the footstep sound panned left to right as the character moved by altering the volume, and as mentioned above it worked better to go from 80/20 to 20/80 than having the sound totally in one ear. It was quite atmospheric. I think it would work well with something like Jumping Jack where much of the focus is on horizontal music.

It could also add to a vertical shmup game if enemy fire is in the left / right channel according to whether it's to the left or right of the player's ship, helping you to instinctively swerve away

@Lee Bee,

The first UK NICAM stereo broadcast was made in May 1986 on BBC2, even though the first stereo TV was sold in 1982 (I assume for watching VHS).

I'm aware that the MSX had Stereo, but I don't know about other 8 bit micros.

All this waffle, is a long way of me saying it probably was not as important back then as it would be if you were selling a computer now.

Nienn Heskil wrote: ↑Mon May 01, 2023 3:16 pm One thing I haven't seen yet on ZX is a game with real stereo panning, i.e.taking objects positions into account. Use both left/right channels to play back the fx with simulated panning (different volumes), central channel for 'system' and/or player fx that need to be centered. Idk if this would make sense in 2d games (scrolling - yes, flip-screen - ... depends), but it definitely would in 3d ones, i.e. first-person action and the like. Of course, this leaves no channels for music, buuut subjectively, seeing the way AY music is in most ZX games*, it could be even better that way.

Not the Speccy, but the only example I can think of is Burnin' Rubber, the pack in game on the Amstrad Plus/GX4000 machines. As you overtake cars, you hear the sound from the appropriate speaker position and I think there is at least some degree of panning attempted (though I've not studied it close enough to be sure).

Probably there because stereo speakers in the monitor was considered one of the selling points from an upgrade perspective. Being only a small monitor it wasn't actually that notable when played out loud though, but plug in some headphones and it definitely added to the gameplay.

Turtle_Quality wrote: ↑Thu May 04, 2023 9:13 am The first and only Javascript game I made was a Sokoban where the footstep sound panned left to right as the character moved by altering the volume, and as mentioned above it worked better to go from 80/20 to 20/80 than having the sound totally in one ear. It was quite atmospheric. I think it would work well with something like Jumping Jack where much of the focus is on horizontal music.

It could also add to a vertical shmup game if enemy fire is in the left / right channel according to whether it's to the left or right of the player's ship, helping you to instinctively swerve away

Yep - I nearly forgot by now, but engines like RPG Maker or Game Maker also allow this sort of panning with sound effects (or even the music).

Re vertical shmups, maybe if the player is centered and the screen also scrolls left/right according to his movement. But if it only scrolls vertically, I can see that getting confusing fairly fast! I think most of the time it's better to use objects' X positions onscreen, as usual.

Nitrowing wrote: ↑Thu May 04, 2023 8:27 am In the 1980's, it wasn't an issue of the computer being mono speaker - TV's were mono as were the majority of consumer music players.

PeterJ wrote: ↑Thu May 04, 2023 9:22 am it probably was not as important back then as it would be if you were selling a computer now.

Absolutely, stereo TV wasn't really common until the 90s. Even late Amiga models were still designed to be heard in mono.

I'm quite happy that the Speccy is mono - it's nice and simple. If I were going to make a modern Speccy with stereo, I'd allow each channel to play in only one of two stereo positions: centre (default) or "wide" (heard equally on both sides). Anything more would add unnecessary complication IMHO. I don't like panning effects (sounds coming from one side), I find them jarring.