Improving perceived loudness when system is constrained

[Brian jojade]

Re: Improving perceived loudness when system is constrained

O.K, so you can actually hear the problem AND measure it? That gives you a solid target to work with. 2db above ambient is not very much, to be sure. Probably just enough that you can make out the sound. The probable easiest solution is to raise ambient noise by 2db in the room, and the problem would be eliminated.

 

[Max Warasila]

Re: Improving perceived loudness when system is constrained

O.K, so you can actually hear the problem AND measure it? That gives you a solid target to work with. 2db above ambient is not very much, to be sure. Probably just enough that you can make out the sound. The probable easiest solution is to raise ambient noise by 2db in the room, and the problem would be eliminated.

Whew I'm glad I'm not the only one who was questioning the ability of people to be regularly noticing 2dB.

 

[Daniel Postilnik]

Re: Improving perceived loudness when system is constrained

Whew I'm glad I'm not the only one who was questioning the ability of people to be regularly noticing 2dB.

We did an additional couple of tests and found that in the early morning, when ambient is low, there's about 13dB of instructor voices coming through several walls.

Also, we set up a sound system inside the apartment, played 630Hz at 115dB and tried to figure out where it would come back down into the studio. The answer was everywhere and nowhere. Not able to locate a single point of leakage.

 

[Jason Lavoie]

Re: Improving perceived loudness when system is constrained

We did an additional couple of tests and found that in the early morning, when ambient is low, there's about 13dB of instructor voices coming through several walls.

Also, we set up a sound system inside the apartment, played 630Hz at 115dB and tried to figure out where it would come back down into the studio. The answer was everywhere and nowhere. Not able to locate a single point of leakage.

Buy the tennant some nice plush carpet with thick underpadding?

Jason

 

[Max Warasila]

Re: Improving perceived loudness when system is constrained

I'd just tell them that they have a free pass to the club and it's classes and encourage them to enjoy the leaking sound, fwiw. Who knows- it might actually work. If they like the club and are into it's services, they won't mind as much.

 

[Brad Weber]

Re: Improving perceived loudness when system is constrained

Daniel, hopefully your consultant already considered this but have you looked at ASHRAE or any other sources that may provide some reference acceptable ambient noise levels for that type of space? I understand the tenant may be upset that they hear anything but unless their lease or sales agreement supports that they should expect to not hear anything then it may legally be a moot point. It may not make the tenant happy to hear that but if they understand that all of this effort is being expended just to try to make them happy and not because it has to be that may help.

If it is 'everywhere' I'd be looking at the plans for vertical chases, ductwork, etc. that the two spaces may share. And if the same issue does not apply to an even greater degre on intervening floors I'd be looking very carfeully for what may make that particular condition different from the others.

I once ran into a situation where a renovated building ended up with classrooms over a club. They went to great lengths to address direct vertical sound isolation over the main club area and seemed to have done a good job there, however they still encountered noise virtually everywhere in the spaces above. Didn't take long to find that in back of house areas just outside the main club floor were a number of penetrations of the slab left from original piping that had been removed, for example the bathrooms downstairs had originally had matched bathrooms directly above with numerous vertical plumbing and electrical connections that had all been removed during the renovation. Because they built walls upstairs right over the penetrations they never filled the resulting holes in the slab, thus allowing noise to get into the walls on the upper floor and from there also into the ceiling space. The real point of bringing this up is that sometimes small flanking paths that are not immediately evident can manifest as something more general while significantly limiting the overall isolation

 

[Jeff Babcock]

Re: Improving perceived loudness when system is constrained

The white/pink noise signal idea is certainly useful, and is far more likely to be a cost effective solution than addressing the structure. I would pursue that first if it were me...... treat with that, as close to the 5th floor spaces as possible, then fall back to physical treatment if it is still not satisfactory.

http://www.atlassound.com/Solutions/Categories/1228/SOUNDMASKING.html


I would recommend someone like Wes Lachot or Geoffrey Hedgeback for consultation on further possible treatment techniques if you need to address the structure further, like HVAC mufflers and other solutions.



Cheers
Jeff

 

[Daniel Postilnik]

Re: Improving perceived loudness when system is constrained

I understand the tenant may be upset that they hear anything but unless their lease or sales agreement supports that they should expect to not hear anything then it may legally be a moot point.

The lease states that no noise should be heard by one tenant coming from another tenant. We share the same landlord.

 

[Brad Weber]

Re: Improving perceived loudness when system is constrained

The lease states that no noise should be heard by one tenant coming from another tenant. We share the same landlord.

There would seem to have to be some nominal source and receiver noise levels assumed such that the base building construction would provide 'reasonable accommodation' for tenants to comply with the lease condition. If I understand correctly, you have closer tenants with no similar issues which suggests the problem is not necessarily solely a source level issue. So maybe try to get the two parties that signed a lease with such a ridiculous condition together and let them figure out whether the issue is excessive noise (your's to address), an issue with the base building sound isolation (the landlord's to address) or unrealistic expectations by the other tenant (the landlord's to address with that tenant).

I also have to say that type of requirement can make the situation much more complicated as you are dealing with subjective perception of the noise meaning not only any personal preferences related to the noise but potentially also details such as the hearing acuity of the one tenant, the frequency content of the noise and any time varying component to the noise. For example, a tonal noise that varies in level over time may not be as acceptable as a constant, broadband noise even if both have the same peak overall dB level.

I would recommend someone like Wes Lachot or Geoffrey Hedgeback for consultation on further possible treatment techniques if you need to address the structure further, like HVAC mufflers and other solutions.

Highly qualified studio consultants, but this is not a studio and studio acoustics versus commercial building acoustics is a bit like studio sound versus live sound - many similarities but also many potential differences. Those gentlemen may be very able to help but there are acousticians and acoustical consultants who may not be as experienced in studio acoustics yet are very experienced and qualified in this type of situation.

 

[Dick Rees]

Re: Improving perceived loudness when system is constrained

The lease states that no noise should be heard by one tenant coming from another tenant. We share the same landlord.

What would you be if you were an inclined plane wrapped helically around a central axis???

SCREWED

Sad news is that if the tenant who is the sore spot cannot be negotiated with, the totally ridiculous lease conditions mean that you'll have to buy the building or find another spot. The way the lease is written, there is no way in H*** that you can do anything reasonable or affordable. It all comes down to the perception of the offended individual. They have all the power, you have none and no recourse whatsoever. Even if you get it silenced, if they even imagine they hear something or hear something from some other source and ascribe it to you, you're toast.

As has often been said, there's no technical solution for what is a personal problem.

 

[Rob Timmerman]

Re: Improving perceived loudness when system is constrained

There would seem to have to be some nominal source and receiver noise levels assumed such that the base building construction would provide 'reasonable accommodation' for tenants to comply with the lease condition. If I understand correctly, you have closer tenants with no similar issues which suggests the problem is not necessarily solely a source level issue. So maybe try to get the two parties that signed a lease with such a ridiculous condition together and let them figure out whether the issue is excessive noise (your's to address), an issue with the base building sound isolation (the landlord's to address) or unrealistic expectations by the other tenant (the landlord's to address with that tenant).

I also have to say that type of requirement can make the situation much more complicated as you are dealing with subjective perception of the noise meaning not only any personal preferences related to the noise but potentially also details such as the hearing acuity of the one tenant, the frequency content of the noise and any time varying component to the noise. For example, a tonal noise that varies in level over time may not be as acceptable as a constant, broadband noise even if both have the same peak overall dB level.


Highly qualified studio consultants, but this is not a studio and studio acoustics versus commercial building acoustics is a bit like studio sound versus live sound - many similarities but also many potential differences. Those gentlemen may be very able to help but there are acousticians and acoustical consultants who may not be as experienced in studio acoustics yet are very experienced and qualified in this type of situation.

Yep.

To the original poster,
Noise control is a rather different branch of acoustics than room acoustics (although there is some overlap), so it may be worthwhile to contact a firm that specializes in noise control. Some resources that may help:
Institute of Noise Control Engineering | Primary Organization for Noise Control Engineering Technology
NCAC : National Council of Acoustical Consultants : Home Page

 

[Fred Allman]

Re: Improving perceived loudness when system is constrained

We did an additional couple of tests and found that in the early morning, when ambient is low, there's about 13dB of instructor voices coming through several walls.

Also, we set up a sound system inside the apartment, played 630Hz at 115dB and tried to figure out where it would come back down into the studio. The answer was everywhere and nowhere. Not able to locate a single point of leakage.

One two three four...go! go! go! go! Lets Go! faster! faster! faster! go! go! go! go! I have seen situations where the noise floor was above the annoying rhythmic nuances of fitness instructors huffing and puffing into a mic, yet tenants in the building were in uproar over this.

There is a response earlier that suggested phased line array speakers. This is actually a very valid approach because you can use them to evenly pressurize the room with sound so you do not have to turn it up as loud as you would with a room full of highly directional point and shoot boxes...

 

[Ivan Beaver]

Re: Improving perceived loudness when system is constrained

There is a response earlier that suggested phased line array speakers. This is actually a very valid approach because you can use them to evenly pressurize the room with sound so you do not have to turn it up as loud as you would with a room full of highly directional point and shoot boxes...

Maybe I missed that post-I would like to learn more about "phased line arrays" and how they can provide even sound around the room.

Can you enlighten any?

 

[John Roberts]

Re: Improving perceived loudness when system is constrained

Maybe I missed that post-I would like to learn more about "phased line arrays" and how they can provide even sound around the room.

Can you enlighten any?

I think he is talking about one of my old hypotheticals about a speaker arrangement that reinforces in the near filed but cancels in the far field. I have run this up the flagpole several times with no knowledgeable speaker guy "ever" saluting it. :-( In my dreams this would mainly work for reducing long wavelength bass leakage, not midrange from instructors yelling.

I say go for some low power FM transmission and put all the exercisers on ear buds.

JR

PS: No I don't know how to do it, I'm not the speaker expert like you guys...

 

[Ivan Beaver]

Re: Improving perceived loudness when system is constrained

I think he is talking about one of my old hypotheticals about a speaker arrangement that reinforces in the near filed but cancels in the far field. I have run this up the flagpole several times with no knowledgeable speaker guy "ever" saluting it. :-( In my dreams this would mainly work for reducing long wavelength bass leakage, not midrange from instructors yelling.

I say go for some low power FM transmission and put all the exercisers on ear buds.

JR

PS: No I don't know how to do it, I'm not the speaker expert like you guys...

I must have missed that "technique". I am not sure how it would be done-at least across a wide range of freq. and over a decent sized area (ie more than a couple of listening positions.

 

[John Roberts]

Re: Improving perceived loudness when system is constrained

I must have missed that "technique". I am not sure how it would be done-at least across a wide range of freq. and over a decent sized area (ie more than a couple of listening positions.

Me either... My initial concept was to bump bass up a few dB say in the middle of a club dance floor, with perhaps a few dB of cut away from the power zone... Perhaps for large outdoor concerts that get noise complaints from neighbors, provide a power zone (like an intentional power alley) for the audience that wants it loud and less loud for all others. Ideally some far field cancellation, but I do not know how to do that either.

IIRC there was an old experimental stereo system where both speakers were not pointed at the listener but pointed at each other and the listeners were always off axis. This was an attempt to smooth the relative level balance between stereo speakers when not same distance from each speaker. If instead of two stereo speakers they were playing opposite polarity mono pointed at each other. The direct sound field should cancel while off axis ?? maybe not so much?

I repeat I do not have a serious idea for how to do this and even my best guess is not going to suppress vocal range several floors away.

My serious suggestion is low power FM transmitter and ear buds...

JR

 

[Ivan Beaver]

Re: Improving perceived loudness when system is constrained

OK-I just figured out how to do it-with NO audio from the sound system getting out of the room.

I forgot the name-but there is a highly directional system uses RF for the transmitting freq (not sure of the freq) and when it hits a person it is demodulated and you hear the audio. I have seen it demonstrated and it is quite amazing.

Now it would take a lot of them to cover a room-but if there is enough budget-it could be done.

Then the only sound that would be getting out of the room would be the impact of the participants feet hitting the floor-and groaning acoustic instructions and so forth.

 

[John Roberts]

Re: Improving perceived loudness when system is constrained

And their brains boiling from the RF energy...

of course small normal speakers by each person would probably be cheaper.

JR

 

[Fred Allman]

Re: Improving perceived loudness when system is constrained

I think he is talking about one of my old hypotheticals about a speaker arrangement that reinforces in the near filed but cancels in the far field. I have run this up the flagpole several times with no knowledgeable speaker guy "ever" saluting it. :-( In my dreams this would mainly work for reducing long wavelength bass leakage, not midrange from instructors yelling.

I say go for some low power FM transmission and put all the exercisers on ear buds.

JR

PS: No I don't know how to do it, I'm not the speaker expert like you guys...

Most manufacturers are on this bandwagon already. Look at the JBL CBT series or Sennheiser K series and there are a few others such as Bose Pro. These work great but you will need to augment the bass on all of these in one way or another. The principle is the same on all of these and phase cancellation is a key to making them perform. Some of these are already are being used in movie theaters and churches which usually have difficult to work with acoustic challenges. The end result is usually more than acceptable if the installation is designed well.

 

[Brad Weber]

Re: Improving perceived loudness when system is constrained

One two three four...go! go! go! go! Lets Go! faster! faster! faster! go! go! go! go! I have seen situations where the noise floor was above the annoying rhythmic nuances of fitness instructors huffing and puffing into a mic, yet tenants in the building were in uproar over this.

There is a response earlier that suggested phased line array speakers. This is actually a very valid approach because you can use them to evenly pressurize the room with sound so you do not have to turn it up as loud as you would with a room full of highly directional point and shoot boxes...

Most manufacturers are on this bandwagon already. Look at the JBL CBT series or Sennheiser K series and there are a few others such as Bose Pro. These work great but you will need to augment the bass on all of these in one way or another. The principle is the same on all of these and phase cancellation is a key to making them perform. Some of these are already are being used in movie theaters and churches which usually have difficult to work with acoustic challenges. The end result is usually more than acceptable if the installation is designed well.

Just being some form of 'line array' is not necessarily beneficial or even desirable nor would using such speakers inherently "...evenly pressurize the room with sound so you do not have to turn it up as loud...". In many cases a distributed system with a number of speakers each run at a lower level might actually be more beneficial, but the important point is that until you identify the related sound transmission paths it is impossible to know that anything other than simply turnining what you have down will provide any beneficial improvement.