Reverse-engineering my speakers' API to get reasonable volume control • Hacker News Board

Re: Reverse-engineering my speakers' API to get reasonable volume control

#31

Post by kevin_thibedeau » Sat, Jul 27, 2024, 1:55 AM UTC

rahimnathwani wrote: post #25

AceJohnny2 wrote: post #7

Earlier quoted context omitted.

Tangential fun fact: amps have a fixed gain, because it's hard to make a variable gain without distortion [1]. The volume knob doesn't control amplification, in fact it controls an attenuation stage, because it's easier to make variable attenuation with low distortion. [1] that's why there were so many different "classes" of amps, they're all making different tradeoffs about how they're doing the amplification.

According to Claude, the attenuation stage is before the power amp stage. Does that mean worse SNR whether the volume is controlled using the volume control or via the input? (Ignoring the additional quantization issue with a scaled digital input.)

Class D doesn't have any attenuation. This is a big factor in their greater efficiency.

Re: Reverse-engineering my speakers' API to get reasonable volume control

#32

Post by laurencei » Sat, Jul 27, 2024, 2:03 AM UTC

Hey OP - if your thinking about a smart knob with haptic feedback etc - check this open source project out that you can build yourself - its amazing:

https://github.com/scottbez1/smartknob

Video demo here: https://www.youtube.com/watch?v=ip641WmY4pA&t=1s

Re: Reverse-engineering my speakers' API to get reasonable volume control

#33

Post by jamesbvaughan » Sat, Jul 27, 2024, 2:10 AM UTC

laurencei wrote: post #32

Hey OP - if your thinking about a smart knob with haptic feedback etc - check this open source project out that you can build yourself - its amazing: https://github.com/scottbez1/smartknob Video demo here: https://www.youtube.com/watch?v=ip641WmY4pA&t=1s

That seems like it could be perfect. Thanks!

Re: Reverse-engineering my speakers' API to get reasonable volume control

#34

Post by swyx » Sat, Jul 27, 2024, 2:15 AM UTC

jamesbvaughan wrote: post #5

kogir wrote: post #3

While I’m all for physical controls, especially ones that self-adjust to reflect the state of the remote device at all times, I wonder if the author just doesn’t know you can finely adjust volume in iOS control center by force/long pressing and then dragging.

This is a great point! When I'm using AirPlay, that feature is really useful. I'm more often using Spotify Connect though, where I'm limited to either using the physical volume buttons on my phone, the small slider in the desktop app, or the slider that's many clicks in to the Spotify mobile app. In reality though, this project is more about the fun of it than about it being a really pressing need.

spotify has so many user hostile practices that I am completely mystified why the majority of the population seems to prefer them in a world where youtube music exists.

Re: Reverse-engineering my speakers' API to get reasonable volume control

#35

Post by possibleworlds » Sat, Jul 27, 2024, 2:17 AM UTC

Nice speakers! I'm guessing the model, if correct here are some spins for those interested https://www.erinsaudiocorner.com/loudspeakers/jbl_4329p/

Weird you can't limit digital output. I also listen mostly at low volumes and have the same issue. Part of the reason I chose Sonos is this is built in across all products, alongside an effective loudness toggle. This has been particularly helpful with some little Genelec 8010s I use as desktop speakers plugged into a Sonos Port.

Re: Reverse-engineering my speakers' API to get reasonable volume control

#36

Post by jamesbvaughan » Sat, Jul 27, 2024, 2:23 AM UTC

swyx wrote: post #34

jamesbvaughan wrote: post #5

Earlier quoted context omitted.

This is a great point! When I'm using AirPlay, that feature is really useful. I'm more often using Spotify Connect though, where I'm limited to either using the physical volume buttons on my phone, the small slider in the desktop app, or the slider that's many clicks in to the Spotify mobile app. In reality though, this project is more about the fun of it than about it being a really pressing need.

spotify has so many user hostile practices that I am completely mystified why the majority of the population seems to prefer them in a world where youtube music exists.

The only competitor that I've given a fair shot is Apple Music. I'm not thrilled with either. Between those two, Spotify wins solely for Spotify Connect. I much prefer the way it works to AirPlay.

I haven't really tried YouTube Music, but I'll give it a go. I've been meaning to try out Tidal too but haven't yet.

Re: Reverse-engineering my speakers' API to get reasonable volume control

#37

Post by Dwedit » Sat, Jul 27, 2024, 2:33 AM UTC

What the hell browser makers... Make it so that file:// URLS are extremely locked down and doesn't have enough rights to even fetch files in the same directory (or even itself), yet grant localhost URLs full permissions...

There's a reason why local web applications aren't a collection of HTML and JS files, and are instead full copies of the Chromium browser.

Re: Reverse-engineering my speakers' API to get reasonable volume control

#38

Post by gregoryl » Sat, Jul 27, 2024, 2:44 AM UTC

possibleworlds wrote: post #35

Nice speakers! I'm guessing the model, if correct here are some spins for those interested https://www.erinsaudiocorner.com/loudspeakers/jbl_4329p/ Weird you can't limit digital output. I also listen mostly at low volumes and have the same issue. Part of the reason I chose Sonos is this is built in across all products, alongside an effective loudness toggle. This has been particularly helpful with some little Genelec…

How are you going with the new Sonos app upgrade?

Re: Reverse-engineering my speakers' API to get reasonable volume control

#39

Post by ly » Sat, Jul 27, 2024, 2:56 AM UTC

I think the article incorrectly states that KEF is owned by Harman, I can only find evidence on the contrary.

Re: Reverse-engineering my speakers' API to get reasonable volume control

#40

Post by jamesbvaughan » Sat, Jul 27, 2024, 3:01 AM UTC

ly wrote: post #39

I think the article incorrectly states that KEF is owned by Harman, I can only find evidence on the contrary.

It seems that you’re correct! I’m not sure what led me to believe that. I’ll update the post when I get home later.

edit: fixed

I dug into the API similarities between the speakers more and it seems like they're both using this software called StreamSDK [1]. I hadn't heard of that and it's given me more to research on these.

[1] https://www.streamunlimited.com/stream-sdk/