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Sure, but the author is wrong. “How old is your son?” “He’s 3.” Clear in context. People write things like dB SPL (A-weighted) in spec sheets because spec she
by klodolph 1y ago
Sure, but the author is wrong.
“How old is your son?” “He’s 3.”
Clear in context. People write things like dB SPL (A-weighted) in spec sheets because spec sheets benefit from being unambiguous. Most of the time it’s really clear, like you’re talking about insertion loss or amplifier gain and there’s only one reasonable way to interpret it.
- viraptor 1y agoThat only works if you're already familiar with the context and system and assume other people are too and don't care about anyone new to that area. (Good luck coming to the audio equipment datasheet with no experience and figuring out what the dB means in each case) "He's 3" works because of the previous question and because everyone had experience of talking about age. dB for anyone not already knowing the answer is like going to another planet and hearing "he's 3". Of course it's on a logarithmic scale, offset to -5 as starting point, counting the skin shedding events - clear in context and you should've known that.
- klodolph 1y agoMaybe I just live on the planet, but I don’t have this problem with dB and to me, it sounds like you’re the alien. Maybe you could elaborate, or give a motivating example? I just don’t remember encountering the problem you’re describing, and it’s unfamiliar to me. There’s something about your experience that I don’t understand, but I don’t know what it is.
- sanderjd 1y agoThe explanation and motivating examples are in the article.
- klodolph 1y agoThe article only had bad examples in it, I was hoping for perspective from someone that made sense. The voltage / power example doesn’t make sense. It’s always power or voltage squared, which are equivalent when the load is resistive.
- sanderjd 1y agoThe articles examples were fine. You (and lots of others here) are being obtuse.
- viraptor 1y agoMoving from EE to audio to radio is enough to go through a few iterations of "people just write dB but mean completely different things". I got used to it, but that doesn't stop me from saying it's a bad idea and we should improve things for the next person.
- klodolph 1y agoAudio, the only gotcha I’ve seen is that -10 is -10 dBu and +4 is +4 dBV. That one is sloppy. But this comment doesn’t illustrate your point, and I still don’t really understand where you’re seeing this.
- sanderjd 1y agoYeah exactly. Lots of people here can't seem to distinguish between "thing that I'm used to" and "thing that is good practice". But these are totally different. I'm used to and thus comfortable with lots of things that are nonetheless terrible!
- 00N8 1y agoI often see pop sci articles saying something like '400 dB would represent a sound strong enough to tear the world apart', or 'military sonar is X dB -- strong enough to liquefy your organs at Y distance'. It's rarely clear to me which of these usages of 'dB' are directly comparable. I think the dB measurement for sonar is a different scale/unit than the one for hearing damage thresholds in air, but I couldn't figure out how to convert between the two last time I spent a few minutes trying to look it up, so in my opinion it can be fairly confusing.
- formerly_proven 1y agoCan you show one of those audio equipment datasheets where it just says "<number> dB" a bunch of times and it's really unclear and confusing?
- drob518 1y agoThen your complaint is with the dropping of units, not dB.
- sanderjd 1y agoYes. The point is that for some reason dB seems particularly susceptible to people dropping the units. For instance, I've heard loudness of sounds described in decibels for my whole life, and first saw the actual units people are describing when I read this article and thread today.
- drob518 1y agoThat’s because you’re a casual observer. If you’re an audio engineer, recording things, designing microphones, amps, or speakers, then you’d know it. Trust me. I’m a digital electrical engineer (computer engineering, basically). I thought that dBs were weird, too. My dad worked in microwave communications systems for his career and dBs are perfectly natural for him. Ditto my daughter who is an audio engineer. Dropping units when you’re working in a particular field is quite common, as who wants to be needlessly wordy when it’s redundant and everyone in the industry understands it? IMO, this article is just the author raging about his own ignorance.
- viraptor 1y agoThere are two paths: "it was weird but then I got used to it, you're just ignorant" or "it was weird, I got used to it, but we should improve the situation". I know which side I want to be on. Even if it takes decades like the data SI prefixes.
- drob518 1y agoYou’re discounting familiarity as being stupid. The real path is “it was weird but once I spent some time with it, it made perfect sense.”
- 1y ago
- RichardLake 1y agoThat depends, the dropped unit could be either a year or a month.
- klodolph 1y agoIt’s understood in context, that’s the point.
- pzo 1y agono it's not - it's assumed by maybe taking the most likely unit (year). But if the conversation is in hospital with your kid having emergency I guess doctor would appreciate to know if they will have to do surgery on 3 months child or 3 years kid.
- icehawk 1y agoA 3 month old kid looks very different to a 3 year old kid.
- pzo 1y agoand thats the exact point - you assume doctor see the kid instead of you calling doctor or doctor is getting briefed by emergency stuff.
- thowawatp302 1y agoExactly! It makes sense in context.
- marcosdumay 1y agoAs long as you construct a strawmen strict enough that can be no ambiguity, and refuses to acknowledge any context where it's not enough, yeah, it always make sense in context.
- sanderjd 1y agoIf you were writing a research paper or engineering artifact rather than having a casual conversation, you should specify the units ("years old") for age as well.
- jayd16 1y agoWhen you say 35 it would be strange for it to be anything but years. 3 days, weeks, months or years are ironically all common units when someone is "3".
- seanhunter 1y agoNo one actually says "my child is 3" meaning anything other than 3 years. They would say "3 days", "3 weeks" or "3 months" meaning the other lengths of time.
- MyOutfitIsVague 1y agoNot where I live. You'd never specify how old somebody is with a bare number and have it mean anything other than years in the US. "My kid is 3" is always 3 years. So is "How old is your Tammy?" "Three". That only ever means years. Every other unit is always explicit. In my decades as a parent and being around other parents of kids and newborns, I've never experienced an exception to this.
- sanderjd 1y agoThat's the point. If you are talking colloquially to someone where you live, sure, whatever, this doesn't matter. But if you are writing something down in some publication for a wide and unpredictable audience, you should use units.
- bigstrat2003 1y agoMost of the time if someone says "he's 3", it is a good bet that they mean 3 years. People usually specify if they mean days/weeks/months with respect to someone's age. Not always, of course, but it's definitely uncommon to drop the unit when it's anything except years.
- timeinput 1y agoBut for insertion loss and amplifier gain it is "just" dB, it's the ratio of the input to the output. The amplifier has a gain of 35 dB means its output is 35 dB higher than the input. If the input is -30 dBm the output is +5 dBm, etc. The reference for an amplifier, or insertion loss is clear in context since you're talking about the gain / loss of a device, and isn't referenced to any fixed scale like db relative to 1 mW, SPL (A-weighted), or 1 volt. On detailed spec sheets they list the gain of amplifiers as xxx dB.