How quite is your room?

[Bartl007]

It's my understanding that even calibrated microphones (UMM6/ omnimic) and REW are invalid for measuring noise floor (Self noise, etc). To do it right you've got to spend some serious cash on microphones designed for the task:

https://www.bksv.com/en/about/waves/WavesArticles/2019/A-quite-place-for-sound

 

[Blumlein 88]

It's my understanding that even calibrated microphones (UMM6/ omnimic) and REW are invalid for measuring noise floor (Self noise, etc). To do it right you've got to spend some serious cash on microphones designed for the task:

https://www.bksv.com/en/about/waves/WavesArticles/2019/A-quite-place-for-sound

Not in your living room. Yes, in those quietest of places on earth or other highly quieted facilities.

The UMM6 does have a self noise rating of 24 db A-wtd. Which is enough in a very quiet place to effect the results a bit. But even at 30 db SPL the difference isn't large versus the correct value. The Umik 1 the way it is usually configured is actually a little higher at 29 db A-wtd.

So you are correct at very quiet areas these microphones might give a falsely high reading.

https://www.minidsp.com/forum/umik-questions/9266-noise-floor

I do have a microphone with a rated 4 db A-wtd self noise. Maybe I need to cal it at higher levels with the Umik and see what it and the Umik show just for kicks.

 

[Bartl007]

Thanks for the info, very helpful!

I'm in the process of planning out a media room space with double wall framing construction/double 5/8" drywall with constrained layer damping compound/communicating double doorways,etc to help increase dynamic range (as well as keeping peace with the neighbors).

If memory serves, 22db is the quietest sound recorded on modern film sound mixes, so in theory if your noise floor is above this level, you're missing some of the details that the director intended you to hear.

 

[Blumlein 88]

Here is some info on NC ratings. Noise Criterion. Which isn't directly the same as a db SPL level. It appears the NC rating is about the same as an octave wide noise measurement at our most sensitive frequencies or about 3 khz. Or close to that.

https://www.engineeringtoolbox.com/nc-noise-criterion-d_725.html

 

[Hipper]

I just (10am weekday) measured my highly treated room with triple glazing but with a busy High Street about 30 metres away - it was around 45dB. It stayed that whether the third glazing piece was open or closed. Yet it sounded quieter when closed.

When I originally installed the third piece of glazing it made both a measurable impact on the frequency response and a perception that things were quieter:

Green is with third glazing added.

This illustrates what others have suggested, that ambient noise is more then just a total dB but needs to be considered across the full frequency range.

 

[dasdoing]

I mostly hear birds and the ocean

 

[lashto]

Apologies if this is already a thread.
I just downloaded a spl meter app. The ambient noise in my room is measuring at 15db if I hold my breath. It's spiking to between 20-30db when I breath or move. It's 22:37 in the evening right now so noise floor will drop again later (01:30-03:00) being the best time for audio . Tweeter hiss is measuring about 22db at 0.5cm roughly.

15db is very quiet. Might be true since you are living in a "village butt end of nowhere". But even without outside noises, it's quite hard to achieve a level that low because of the inside noises: fridge, ventilation, AC, water circuit, PCs, people, pets, etc.

30db is often described as quiet library and should be a good threshold-value for 'quiet'. A typical city apartment/house will be much louder than 30db, even in the middle of the night.

 

[Soniclife]

The reading on the APP is probably A-weighted.

Very likely.
This is A vs Z from my phone, in my office just now.

 

[MarsianC#]

35 dB(A) with computer and HDD's on. UMIK-1.

 

[Wombat]

I live in a rural town(pop. ~10,000). Quite quiet in the evening, maybe.

During the day, traffic, tradesmen, dogs and gardeners constantly make noise.

The more quiet evening time is randomly disturbed by fuckwits with doof-doof car sound systems or window rattling car exhaust systems - or both.

 

[Kal Rubinson]

Last time I checked, I got NC25 (measured with my GoldLine TEF25 analyzer) at my CT place (as long as there wasn't a truck in the neighborhood).

 

[Frank Dernie]

steady 30dBA and ~35dB fluctuating a bit unweighted.

 

[raif71]

I live in a rural town(pop. ~10,000). Quite quiet in the evening, maybe.

During the day, traffic, tradesmen, dogs and gardeners constantly make noise.

The more quiet evening time is randomly disturbed by fuckwits with doof-doof car sound systems or window rattling car exhaust systems - or both.

I'd give a quid if you quit with the quite quiet quip

 

[tmtomh]

My room is the only finished/occupied room in the basement level of my home, is on a concrete foundation with insulation beneath the foundation, carpet and decent undercarpet padding on top of the concrete, two layers of 5/8 drywall on the ceilings and the two walls that face inside the house, one layer of 5/8 on the two walls that face the concrete foundation walls, a solid-core entry door, a double-paned window, and good (though not high-end) insulation behind the walls and above the ceiling. Even with that, it doesn't get below about 25dB A-weighted, and 27-32dB B- and C-weighted - and of course it's higher when there's a lot of activity on the 1st floor or loud trucks and such outside (I live in a city).

I could have spent more on insulation I guess, and I could put weather-stripping on the door jamb to block a little more sound, but I doubt that would make much difference (and the window is required by code for emergency egress from the basement). It's just the reality of residential living, and the room is still quiet enough that it's often possible for me to hear the quiet, approx 32-35dB (A-weighted) fan from my iMac several feet away from the listening position, in the back corner of the room. It is what it is.

Honestly, it makes hi-fi more affordable and less stressful, because I'm not going to worry about getting an amp with SINAD of -125 vs one with -112, or a DAC with SINAD of -122 vs one with -115, if the price differences are huge, given that my ambient room noise is -25dB and I don't listen to music beyond a 95dB peak level.

Finally, I'd make a plug for Decibel X, a free/inexpensive-paid SPL app for iOS (and for all I know, Android too). I don't have a pro-level reference, but I do have a dedicated Radio Shack SPL meter, and my iPhone with Decibel and the Radio Shack meter measure close enough to each other so as to be interchangeable. Both could be inaccurate of course, but even if they are, it seems strange that both would be inaccurate by the same amount in the same direction.

So I'd say that phone apps can certainly be "good enough" for many home applications even if they are not great.

 

[Tks]

As others have mentioned, I would not trust that measurement unless your room/house are pretty unusual (e.g., significant investment in soundproofing, cinderblock construction in a rural location...)

One tip: pay attention to, and mention, the weighting function.

Hey SIY, I've been wondering, do you have any information on apartment standards in the United States concerning soundproofing? Or ones that building construction companies look to when deciding some of these things? Living in apartments sucks fat balls simply due to someone always seemingly being able to hear you, or you them just when something gets slightly loud..

Next place I go, I want it to be an almost desensitization chamber.. (houses aren't possible in NYC so that's off the table).

 

[hege]

Some old UMIK-1 measies from my very quiet basement. Any speaker hiss is easily annoying from 2 meters here.

(Ignore the 1khz harmonics, had a bad USB hub which mic didn't like)

Absolutely everything off

Central ventilation, "silent" PC, speakers, A/C unit fan on

 

[SIY]

Hey SIY, I've been wondering, do you have any information on apartment standards in the United States concerning soundproofing? Or ones that building construction companies look to when deciding some of these things? Living in apartments sucks fat balls simply due to someone always seemingly being able to hear you, or you them just when something gets slightly loud..

Next place I go, I want it to be an almost desensitization chamber.. (houses aren't possible in NYC so that's off the table).

AFAIK, there aren’t any. I developed a really effective spray insulation which can really knock down external noises in apartment and office construction, and the feedback is always, “We can’t pay anything extra for that.”

 

[lashto]

AFAIK, there aren’t any. I developed a really effective spray insulation which can really knock down external noises in apartment and office construction, and the feedback is always, “We can’t pay anything extra for that.”

got some price & measurements for that spray?

 

[Webninja]

I did a lot of research on sound isolation when we were remodeling. I really wanted to do a full decoupling (room within a room). Unfortunately, I couldn’t afford to implement anything but a good insulation. I did find this material that might be of interest to those trying fire ultra quiet rooms.

https://www.acoustiblok.com/acoustiblok-product-lines/acoustiblok-wallcover-noise-barrier/

 

[tmtomh]

I did a lot of research on sound isolation when we were remodeling. I really wanted to do a full decoupling (room within a room). Unfortunately, I couldn’t afford to implement anything but a good insulation. I did find this material that might be of interest to those trying fire ultra quiet rooms.

https://www.acoustiblok.com/acoustiblok-product-lines/acoustiblok-wallcover-noise-barrier/

Interesting! STC53 is pretty good. I would imagine application impacts it considerably, specifically getting as close to 100% coverage of the area in question as possible.

IMHO that's the biggest practical challenge of residential soundproofing - sound will get through any crack, hole, or weak spot, and if you have windows and doors, there's a limit to how much actual soundproofing you can achieve no matter what you do to the other surfaces.