6 ms·

> makes me really doubt that the OP has any practical experience about the things they're talking about. Maybe not, but you can get used to many odd things giv

• rusk 1y ago
  dB for sound in particular aligns with human experience. The (10 -) 1-10 on a volume knob typically aligns with a logarithmic scale because we hear differences in loudness at an order of magnitude. A linear volume knob would be frustratingly useless as you would have to crank it many many many times the higher up you want to go. Presumably hundreds of times. A traditional pot couldn’t do that of course but maybe you could satisfy your curiosity with a rotary encoder?
  • IsTom 1y ago
    You could have log Watts or something, it doesn't have to be dB to be logarithmic.
    • rusk 1y ago
      That would be dishonest. You don’t adjust input power - you adjust attenuation EDIT if you did let’s say approximate power, or measure and present the consumed power (as some systems do) you would still be in a situation about how to present this data. Do you present your users with a simple 1-10 (logarithmic) or a 10 digit display which sweeps over vast ranges of uninteresting values. If you opted for a more compact scientific notation … well guess what that’s also logarithmic but in two parts LOL
      • deleted 1y ago
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    • KeplerBoy 1y ago
      We have a unit for that. It's dBm and very easy to grasp. 0 dBm is 1 mW, every 10 dBm is an order of magnitude more (10 dBm = 10 mW). dB is only confusing if people omit which quantities they are relating. If it's clear like in the case of dBm which relate to 1 mW, it's an awesome tool.
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      • jfengel 1y ago
        Unfortunately, people omit the quantities all the time. Domain experts assume it when talking to each other, and non-experts repeat it without knowing that it refers to anything at all. (I still don't really know what it means for a sound to have "decibels".)
        • jononor 1y ago
          When referring to sound in the physical world, "decibel" mean dB SPL (sound pressure level). Which is defined as the ratio to the smallest perceivable sound pressure level. Unfortunately that is still a bit underspecified, it may be measured with a frequency weighting like A weighting. And then there is the integration time or other temporal aggregation, but that is separate from decibel/log. When in analog audio, it usually means dbV, relative to a reference voltage. And in digital audio, usually dBFS - relative to the maximum amplitude that can be represented.
    • foxglacier 1y ago
      You can't take the log of a quantity with units like watts. It would be log of some ratio of powers, and then it doesn't matter what unit of power you use because they cancel out. Instead, it matters what the denominator in the ratio is so we're back at needing something confusing like dB :(
  • taneq 1y ago
    Ever have a cheap set of external speakers that got super loud in the first quarter turn of the volume knob but were pretty much the same loudness after that? Yeah, linear pot for the volume knob. No need for an encoder and software, though, logarithmic pots are readily available for precisely this reason. :)
    • rusk 1y ago
      No I’ve never had one of those LOL Pots do log and lin scales but they only have a limited angular range.
      • mattmanser 1y ago
        I've actually noticed this two days ago with some bluetooth headphones and my phone. The volume control on my android phone was acting just like this when my headphones were connected. When changing the volume with the phone only a small section of the bottom quarter of the volume control actually made a difference, but the volume controls on the headphone themselves were acting "normally". Usually the phone volume is fine, it only screws up on bluetooth devices (my speakers + my headphones). I have to use the volume control on the device itself to have any good control. This explains the weird behaviour, the phone volume changes are being sent linearly, but the headphone/speaker settings are correct and being set logarithmically. i.e. somewhere a developer working on the bluetooth integration didn't understand the difference, screwed up and never tested it. That it's happening to both my Edifier speakers and my cheapo headphones probably means it's on the stock Android end (it's a pixel phone).
        • Severian 1y ago
          I've had the same issues as you, and here are some things I've done or tried as a remedy. Try going into Android "Developer options" and enable the option "Disable Absolute Volume". Some devices cannot handle the way Android maps the "master" volume of the system to Bluetooth. With the option enabled you will have a separate slider to adjust the Bluetooth volume, and the volume buttons will instead only control the "Media" volume. An alternate thing to do is under the same Developer Options is instead of disabling Absolute control is to change the Bluetooth AVRCP version to at least v1.5. v1.5 AVRCP introduces the Absolute Volume control functionality. But, it could also be what you may have are Bluetooth devices that do not support Absolute Volume, or lack AVRCP v1.5 compatibility. If none of this works, I suggest purchasing the "Precise Volume 2.0 + Equalizer" app. I use this as it gives you more fine-grained control over the number of steps in the volume slider (for example, I now have 100 steps). It also allows you to calibrate the number of steps to a specific device, so you can literally change how many steps from quiet to loud. It's worth all of the $10 it costs, and has other nice quality of life features as well.
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  • nomercy400 1y ago
    Does that also work for showers, with mixing hot and cold water. I feel that a 1% change in the knob/balance goes from too cold to too hot.
    • detourdog 1y ago
      Nothing to do with decibels but the thermostat on the water heater might be set too high. If one lowers the overall temperature the ratio of cold to hot will balance.
      • rusk 1y ago
        You are bounded by a minimum floor for the hot water. Below a certain point you can get legionnaires. To me it seems like one of two things: external pressure between hot and cold is mismatched so a small change to one side overwhelms the weaker flow. Alternatively it might just be a broken or poor quality mixer that isn’t providing the appropriate ‘nuance’ of control, and that may indeed be expressed as some sort of non-linear relationship.
        • detourdog 1y ago
          The thermostat could still be set too high. I think you might be overstating the dangers of legionnaires. It also a simple thing to check and would be the first step in my troubleshooting routine for this complaint. Here is a link describing the dangers. https://www.heatgeek.com/hot-water-temperature-scalding-and-legionella/ https://www.heatgeek.com/hot-water-temperature-scalding-and-...
        • GuB-42 1y ago
          > Below a certain point you can get legionnaires. I know you mean legionnaires' disease, but the idea of a bunch of soldiers getting to your house because you turned your boiler too low made me chuckle. Good thing the US have the third amendment to protect against this.
          • detourdog 1y ago
  • ajuc 1y ago
    Logarithmic scale aligns with human experience. OP isn't criticizing logarithmic scale in general but dB in particular. If dB in particular aligned well with human experience - volume knobs would be labeled with dB values instead of 1-11.
    • rectang 1y ago
      A properly designed volume control affects the sound power output logarithmically, but is labeled linearly (with 1-11 or 0-1 or something like that) to reflect how humans perceive the effect. People in the field get this wrong all the time — for instance, the volume control on ChromeOS appears to be a linear multiplier, yielding a control with huge perceived steps in the output between 0 and 3, and negligible perceived change in the output between 7 and 10. I suspect that the confusing design of the dB contributes towards how often such mistakes get made.
  • losvedir 1y ago
    Nothing in the article and nobody in the comments takes issue with the fact that it's logarithmic. It's everything else that's the problem. (It's a ratio where the base value is situation dependent, and the base of the logarithm varies.)
    • rusk 1y ago
      But the base value is well defined, qualitatively (“a quiet room”), which is fine for what we are talking about which is “experienced loudness”. Once you go past log(3) it really doesn’t matter what the noise was at log(0).
      • sanderjd 1y ago
        I'm sorry, but did you read the article? This is not the complaint. If decibels were used only to measure sound relative to "experienced loudness" there would be no complaint. The complaint is that it is used in many other ways, often without distinguishing what the base unit is.
        • rusk 1y ago
          The issue is that it’s not “well defined” that it’s somehow subjective. But the whole point with a logarithmic scale is the small values don’t matter.
          • sanderjd 1y ago
            This isn't what the article is about!
  • sgarland 1y ago
    Sure, but a. IME, volume controls with 1-10 are nowhere near log b. many manufacturers don’t even do this. A lot of car manufacturers seem to use 0-40 for the stereo volume, which seems completely arbitrary. I’m assuming they decided that’s a good balance between granularity and annoyance, but c’mon… couldn’t have at least capped it at 50? Halfway to 100 feels vaguely more intuitive. This also doesn’t even begin to touch on frequency response curves.
• TheOtherHobbes 1y ago
  This like arguing that aspect ratios are stupid and wrong because sometimes they apply to a screen which is really big and sometimes it's really small and sometimes they apply to a physical print or a photo or a billboard or a vintage TV and sometimes it's a jpg or a PNG. Aspect ratio is a ratio. It can be a ratio between pixel counts, or between print dimensions, or physical display dimensions. All of which are useful in their own way, none of which are directly comparable, all of which are understandable in context. dB is the same. It's a ratio split into convenient steps - more convenient than Bels would be - that compares two quantities. The quantities can be measured in different units. The units are implied by the context. The only mild confusion is the relationship between voltage and power ratios. But that's a minor wrinkle, not a showstopping intellectual challenge.
  • sandblast 1y ago
    Ratios are numbers. They are literally just fractions. No one argues that the numbers don't make sense because you can have different units. But that's what units are for – to know what does the preceding number refer to. Why have a unit that doesn't give you full information?
    • more-nitor 1y ago
      this if a TV seller went bonkers and only said "it's 10:16", can you guess the actual size of that TV?
      • jhbadger 1y ago
        But that's not what is being expressed. You might as well complain that the ratio doesn't give you information on the price, weight, or power usage of the TV.
  • gwd 1y ago
    > Aspect ratio is a ratio. Right, but in this case they only give you one of the two numbers. Imagine being told that your TV had an aspect ration of ":16", and you just have to magically know what the other number means in the context. And sometimes ":16" actually means ":4", because quadratic mumble mumble, and sometimes the number is scaled according to some other "how big it seems to humans" factor; all of which you also just have to know in context.
• NobodyNada 1y ago
  Consider the signal chain of a live audio system, from a singer to a PA. The singer produces sound pressure waves into a mic. These pressure waves are measured in dB SPL, and the microphone's specifications will tell you its sensitivity, maximum sound pressure level, frequency response, on- and off-axis response, and so on. An engineer can look at all these specs to choose a mic based on the environment, how much background noise there is and where it's coming from, the quality and character of the singer's voice, etc. The microphone will produce a voltage, which is measured in dBV or dBu. This voltage travels to a preamplifier, which boosts the signal to a nominal level by applying a gain (in dB, with no units since it's just a dimensionless ratio between input level and output level) and converts it to a digital signal -- measured in dBFS ("decibels full-scale", signal level relative to the maximum level that can fit in the bit-width of the digital signal). Note that all the different signals going into the preamps have wildly different voltage levels -- a kick drum produces much more sound energy than a singer. And the ratio between SPL and voltage is not fixed; different mics have different sensitivities, and an active guitar amp will generate a signal many orders of magnitude stronger than a passive microphone. For some instruments like synthesizers, "SPL" isn't even a concept that makes sense because the sound is produced entirely electronically, rather than by capturing a mechanical wave. So, the preamps are configured to normalize all the incoming signals to one nominal level for processing. After the preamp, the signal goes through a digital signal processing chain. Most of these processing steps will affect the level of the signal, and the amount is measured in dB (without units, since this is a dimensionless ratio between input level and output level. Remember, we're dealing with a fully digital waveform, so there is not even a physical measure of "loudness" or "signal strength" that can apply to the signal at this point.) The signals from all the different sound sources are mixed together, and the mixer's per-channel volume faders are marked in decibels -- usually from +10 to -infinity, with 0 corresponding to "unity gain" (which means the output signal should have the same intensity as the input signal). Again, no units because we aren't measuring a physical quantity, just how much the mixer should change the intensity of the signal. Finally, the signal is converted back to an analog voltage (measured in dBu) and sent to a power amplifier. The power amplifier applies an adjustable gain, and outputs a signal measured in watts (dBm) for sending to the PA system. You might then walk around the room with an SPL meter to ensure the sound is at a safe level; the value you measure will depend on the frequency and directional response of the speakers, as well as how far away from the speaker you're measuring. Throughout this process we had signals in the form of sound pressure, voltage, digital samples, and wattage, at power levels ranging from microwatts to kilowatts. Even a simple physical quantity like sound pressure for a single signal is not straightforward -- how far are you measuring it from, and are you talking about SPL before the microphone or after the speaker? The fact that a single unit is used for all of these different purposes is a feature, not a bug. If my preamp is close to clipping and I turn it down by 3 dB, how much do I need to turn up the gain at my compressor to compensate? Easy -- 3 dB. If we used more "appropriate" physical units at each step of the signal chain, it would be impossible to determine this number quickly or in your head; and would involve taking into account even more factors I haven't mentioned (like input impedances). The fact that decibels are scaled differently depending on whether you're working with voltage or power means that 1 dB corresponds to the same change in loudness everywhere without having to remember whether it's 1 dB of voltage or power.