How to measure / interpret volume attenuation to neighbors

[Rubberducky]

I've moved into a new place and will set up a home cinema room. I want to make sure we don't disturb the neighbors and they are willing to let me do some measurements. Before I do this, I want to make sure I'm measuring the correct thing.

My current plan is to generate pink noise at sufficient volume with REW and use my MiniDSP UMIK1 and check what the level (I'm assuming C weighting is the best choice here) in my room e.g. 1m from the speakers is. Then I want to measure what the level at the other side of the wall is (in the neighbors house). This will give me a difference in C-weighted SPL. (The attenuation of the wall)

Then I could lower the volume of the pink noise until the neighbors can't hear it anymore, even if I pulsate it on and off and measure that level at my place. This tells me the max level I can play at during the night. During the day I might be able to go a bit higher if I check with the neighbors.

The question is: am I taking the correct variables into account? Bass frequencies will be attenuated much less than the higher ones, but this is taken into account in the C-weighted SPL already. People are more sensitive to different frequencies, but this is also taken into account when C-weighting. Any tips / tricks here?

Thanks!

 

[staticV3]

Since the UMIK-1 has pretty high self-noise, I would strongly suggest you use the regular REW Measurement Sweep with the highest FFT length, instead of Pink Noise.

You can export the sweep as a wav file, then do the playback and mic capture from two different systems.

Also, use the Java EXCL input and make sure that the UMIK's cal file is applied to that input.

 

[staticV3]

On second thought, there are two issues with my method:
For the playback/capture from separate systems to work, the microphone in your neighbor's place has to "hear" the acoustic ref signal played back on your HT system. Since this is a high frequency chirp, it'll be the first sound to disappear as you turn down the volume.

With REW's measurement sweep, you'd be left with just frequency response graphs, so no single dB(C) SPL values.

I think especially due to the UMIK's high self-noise, you may be better off leaving it in your home Cinema room to record the SPL there, and using just your ears at your neighbor's place to check for audibility there, as they will hear more than the UMIK.

That way, you can use all kinds of test tones (pink noise, sweeps,bass kicks, actual soundtracks or movies), and monitor levels either as single dB(C) levels, or as more detailed frequency graphs using the RTA.

 

[kemmler3D]

Maybe you could set the levels for SPL at the neighbor's (with a speaker on their side of the wall) and then do relative measurements from there.

However, The main thing is knowing at what playback level in your room they can start to hear bass frequencies in their room.

The relevant measurement is audibility, so I agree that taking measurements in your room, and then getting the neighbor to rate audibility at a given SPL - finding out the threshold of inaudibility (or at least, inoffensiveness) is the key here.

Actually it would be useful to have a realtime SPL meter running in your home theater room that would tell you when you need to turn it down, once you establish that.

I guess C weighting is the way to go either way, though.

 

[boxerfan88]

C weighting will exclude quite a lot of bass from the measurement. One might miss out the impact of bass to the neighbours.

Worse still, bass can really travel far. Bass pounding late at night is disturbing.

I’d recommend Z weighting.

 

[Rubberducky]

Thanks already for the replies!

So if I understand you all:
- The internal noise of the UMIK 1 is too high to actually measure the dB drop in the wall accurately (unless I would turn up the volume in my place extremely loud until there is enough headroom to measure)? So better to do it by ear.
- Given that I know which (correctly weighted) SPL of pink noise is not audible at the neighbors, using an RTA that tells me SPL during movies should be representative, even though the spectrum is not the same as the pink noise, because this is taken into account when calculating the SPL?

C weighting will exclude quite a lot of bass from the measurement. One might miss out the impact of bass to the neighbours.

Worse still, bass can really travel far. Bass pounding late at night is disturbing.

I’d recommend Z weighting.

Is that really the case? The bass will travel more easily through walls, but that just means that a lower SPL at my place will cause audible noise at the other side. I was under the assumption that C-weighting already correctly takes into account the psychoacoustics while not under-estimating bass.

 

[Sokel]

Actually it would be useful to have a realtime SPL meter running in your home theater room that would tell you when you need to turn it down, once you establish that.

I guess C weighting is the way to go either way, though.

REW has a real time SPL logger with the advantage to measure absolute peak values also but I admit I don't know how it works with U-Mic.
He could just record the same stuff in the two places and compare it.

(same with A and C weighting)

 

[audio_tony]

@Rubberducky just be careful playing tones at high volumes - your speakers might not appreciate it.

I think pink noise is a good test, because there is a fair amount of LF in pink noise, and that's likely to be the biggest transfer of sound.

Depending on the construction of the house, frequencies up to around 2k will likely be audible at high levels, and anything above that will most likely be 'filtered' by the walls etc.

We can sometimes hear our upstairs neighbours' TV (we're in an apartment) and the floors are concrete and quite thick, with laminate wood flooring (the wood flooring doesn't help).

 

[Pareto Pragmatic]

This is very considerate of you, and I am sure your neighbors do and will appreciate it.

Do what you can before these measurements. Don't have a rear ported sub backed against the dividing wall, that kind of thing.

I would be most concerned about bass. So you may want to add a bass track to the testing. In fact, if you are most concerned about movie playback, why not use some intense battle scene with lots of explosions? Those will be high SPL with a lot of intense sound impulses/sharp peaks.

The only measurement on the neighbor's side that matters is what they think. So their ears will trump your REW numbers. So I would ask them two questions: When can you hear it, meaning at all if you listen very closely? When it is a problem? Compare SPL in your space, and you will know when you are starting to intrude, and when you are starting to bother them. Start with pink noise, then go battle scene.

You may want to do some tests with and without subwoofer. Turning the sub off might gain you more volume, which might or might not be good for you for some things.

Knowing how their space is set up will help. Does their bedroom back up to your space, or is it the main room? (most likely main room, given usual architecture that keeps water lines and such near each other for adjoining units. Bedrooms tend to back to bedrooms.)

Invite them over for a movie/music of their choice and some drinks/snacks. Make this a social event, make it pleasant. A bit of good will goes a long way. Talk about when they need quiet, and when they might be ok with a bit of bleed through. If you know that at a certain time they don't mind a song "turned up a bit" then turned down after that song, you will be a lot happier and less stressed about cranking the volume a bit at 2pm for 5 minutes.

I hope you can get loud enough for you without bothering them!

 

[computer-audiophile]

Why measure? You could also just run a loud programme and then visit the neighbours and see if you/they hear anything. Luckily I live in a solid house in a nice neighbourhood. Anything else would piss me off.

 

[SSS]

Play it for your maximum loud and wait whether neighbours will knock at your door.

 

[Rubberducky]

This is very considerate of you, and I am sure your neighbors do and will appreciate it.

Do what you can before these measurements. Don't have a rear ported sub backed against the dividing wall, that kind of thing.

I would be most concerned about bass. So you may want to add a bass track to the testing. In fact, if you are most concerned about movie playback, why not use some intense battle scene with lots of explosions? Those will be high SPL with a lot of intense sound impulses/sharp peaks.

The only measurement on the neighbor's side that matters is what they think. So their ears will trump your REW numbers. So I would ask them two questions: When can you hear it, meaning at all if you listen very closely? When it is a problem? Compare SPL in your space, and you will know when you are starting to intrude, and when you are starting to bother them. Start with pink noise, then go battle scene.

You may want to do some tests with and without subwoofer. Turning the sub off might gain you more volume, which might or might not be good for you for some things.

Knowing how their space is set up will help. Does their bedroom back up to your space, or is it the main room? (most likely main room, given usual architecture that keeps water lines and such near each other for adjoining units. Bedrooms tend to back to bedrooms.)

Invite them over for a movie/music of their choice and some drinks/snacks. Make this a social event, make it pleasant. A bit of good will goes a long way. Talk about when they need quiet, and when they might be ok with a bit of bleed through. If you know that at a certain time they don't mind a song "turned up a bit" then turned down after that song, you will be a lot happier and less stressed about cranking the volume a bit at 2pm for 5 minutes.

I hope you can get loud enough for you without bothering them!

Adding some real world scene to the test is indeed a good idea. Also for myself to get an idea of what they might hear. Thanks. And indeed, I agree, it just matters what they hear. I'd just like to have something to go by. It's difficult to gauge absolute volume when watching a dynamic movie. So having some data + an RTA when in doubt can give me peace of mind.

Why measure? You could also just run a loud programme and then visit the neighbours and see if you/they hear anything. Luckily I live in a solid house in a nice neighbourhood. Anything else would piss me off.

I want to measure because I'm 100% certain that If I would blast movies at loud volumes they would be disturbed. And I don't like the feeling of constantly needing to "guess" whether something is too loud. So having some data to go by makes sense.

 

[Cbdb2]

I would not bother with pink noise. Constant noise is not nearly as noticeable (or annoying) as intermittent noise, especially low freqs. Use a music track with pumping bass/kick drum or a movie with lots of explos. and your ears. You might want to check the difference with and with out your subwoofer (I hope its not near your neighbours wall)

 

[Cbdb2]

Adding some real world scene to the test is indeed a good idea. Also for myself to get an idea of what they might hear. Thanks. And indeed, I agree, it just matters what they hear. I'd just like to have something to go by. It's difficult to gauge absolute volume when watching a dynamic movie. So having some data + an RTA when in doubt can give me peace of mind.


I want to measure because I'm 100% certain that If I would blast movies at loud volumes they would be disturbed. And I don't like the feeling of constantly needing to "guess" whether something is too loud. So having some data to go by makes sense.

You only need to measure below 200hz. Unless the wall is substandard, pun intended.

 

[ozzy9832001]

I think it depends on what the walls/floor/ceiling are made out of and where your neighbors are in relation to your room (above, below, next to). Low end sounds very well may cut through the neighbors rooms like a hot knife through butter. I can play a tone sweep on one end of my house at standard 83dB and hear it all the way on the other side with every window and door closed in between. Now, usually apartment complexes have some sort of soundproofing between structures to prevent overly annoying things from happening, but it's not a given.

 

[Flaesh]

just run a loud programme and then visit the neighbours and see if you/they hear anything

I think this is the correct method.

I don't like the feeling of constantly needing to "guess" whether something is too loud. So having some data to go by makes sense.

Yeah, measure SPL in your listening room when the neighbors can’t hear it and when they can still tolerate sounds (according to time of day, type of content and so on)
I believe that after a while you will be able to easily determine the appropriate volume without a microphone.

Play it for your maximum loud and wait whether neighbours will knock at your door.

One day the police came to us when we listened to the F. Dupré's "Ruins" at full volume, but door bell could not be heard because of the music..

 

[pseudoid]

You really are not looking for accuracy in the absolute levels; you are just trying to figure out the difference (delta of A-B << like an insertion loss of the wall in between).
But, your testing (being a 'nice guy' that you are) may pique the interest of the neighbor and -- depending on their character -- they may demand absolute quiteness. << A hornets' nest!
You'd like being my neighbor: I always keep my music on, day and night. I started doing this decades ago, so that I don't ever have to have arguments with my neighbors about their loud (and probably sh*tty) music.

 

[Flaesh]

Once upon a time, my neighbors were a family of good young metalheads; the one who was disturbed by the neighbor's music simply turned his music louder.
That loudness war was fought with some pretty rubbish weapons. But now I don't have neighbors with an audio system capable of, say, 120 dB peak for such entertainment.

 

[pseudoid]

Once upon a time, my neighbors were a family of good young metalheads; the one who was disturbed by the neighbor's music simply turned his music louder.

What I have also learned is that a rude neighbor may become even more rude, if you knock on their door.
To avert such confrontations, it becomes best to just call the local police and have them handle the neighborhood noise problems.

 

[Flaesh]

"Our" policemen said that they did not come on call, but simply heard "Ruins" from the other side of the block.
About 200 m if they didn't lie.