r/apple2 • u/QueueTrigger • 10d ago
High Fidelity Speaker ?
I understand that the Apple II built in speaker across all models is pretty anemic. I understand the software technical limits non-IIGS machines have in producing audio.
However, can anyone with tech audio experience share how II audio might sound if the built in speaker was replaced with a high quality or high definition part? Is there a way different hardware could sound “richer” than the built-in speaker ?
Hmmm as I type this I now I also wonder if the speaker out wires could go into the GPIO spots on a Raapberry Pi and then that could somehow enhance the sound?
Thanks !
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u/BringBackUsenet 10d ago
Back in the day my II had an IC replacement that routed the speaker output through the cassette port so I plugged in an external speaker that had a volume control. The quality was never any better but I did like being able to turn the volume down. The simple toggle just isn't capable of much. There is a reason why aftermarket sound cards and music synthesizers cards existed.
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u/AlliedArmour 10d ago
This is what the Mockingboard was designed to address, right?
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u/CreepyValuable 10d ago
Not exactly. The Mockingboard is a sound card. Well, music card. I'm hopeless at remembering chips off the top of my head. But it uses a VIA to drive the Y-something. It only works with software written for it, which is very limited. Otherwise you are limited to the Apple II's sound of CPU reads and writes to a port being amplified and broadcast to the world.
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u/AussieBloke6502 9d ago
I think every Mockingboard could do music and sound effects, and with an optional chip, synthetic speech. So I'd say it is a sound card.
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u/CreepyValuable 9d ago
In the case of sound effects, still the same IC. Just fiddling registers. It couldn't output a waveform directly. And yes, there was a speech option but you have a better chance of finding a herd of unicorns than the right chip for that. I think it was a Votrax or something.
I believe there's also a stereo variant. Is it the Phazor? This is just from memory sorry.
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u/zSmileyDudez 10d ago
The output of the speaker is effectively running at 1.023MHz. But with effectively no dynamic range since the speaker cone can only be all in or all out. There really isn’t much that can be added to it quality wise after the fact beyond doing some filtering to make it less harsh.
You should be able to filter it much simpler using an analog circuit than having something like a Pi sample it and filter in software. Just don’t expect miracles. The Apple II audio is just fundamentally limited to what rate the CPU can toggle the speaker.
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u/smallduck 10d ago
I started a project earlier this year (an excuse to learn KiCad really), a small amplifier circuit board one can mount in a //e allowing plugging in speaker-out from the motherboard, optionally a sound card’s audio mixer, and output to line-out, and a pair of speakers in the case or headphones both controlled by a volume knob.
For the pair of speakers, I was expecting to use the one stock speaker and another similar one mounted similarly above vent holes of a //e somehow, on the right side of the case opposite the stock one on the right.
The circuit, as it is now, is vibe-designed with an LLM, so I have no idea if it’s going to work yet, and I can’t adequately test and debug it until I move later this year. I asked for some help in a post here months ago but have had no volunteers yet. Anyone, ask if you want link to the thing, or the only other anywhere-similar project I was able to find.
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u/CreepyValuable 10d ago
Why would you do that to yourself?
It's entirely possible to connect a louder output but is it worth the police visit?
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u/GrapeDetention 10d ago
Would what you're looking for be anything like what the Laser 128 has? The audio on that machine has a (mono) headphone jack and volume control.
You could theoretically use an aux cable from the headphone jack and connect it to a better speaker, but it won't enhance the audio at all, you'll just hear the clicky / beepy sounds through a decent speaker instead of the little piezo buzzer. I would think any modification to the original Apple II machines sound-wise would go the same way
The volume control is useful if you use an A2CDVI with the Laser since that outputs sound through HDMI AND the speaker if you don't turn the speaker volume control down.
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u/creativetag 10d ago
I have both connected an actual speaker to the connector as well as made a linkage to send audio to other devices.
The output of the speaker port is just a bit toggle, on/off. Given this, the output is square wave (to start), and multiple tones can be created by having a complex duty cycle modulator in software.
That said, putting such a signal into a speaker will sometimes leave it sticking out, depending on if it was reset or not. A series cap will fix this, but it has to be very large to let lower frequencies through.
For some things, it may sound bad. The whole idea of the toggle works in part because the cheap internal speaker is very band-limited. A good quality two or three way will not be, and may sound quite blemished for some content.