Reducing low end output.

Hi all,

I use a pair of Impulse Lalis, which I believe are a horn loaded design.I absolutely love them, but I do find myself worrying about how much low end they kick out. Not in terms of the overall sound, but in regards to disturbing my neighbours. I live in a block with people above, below and to one side of my lounge, I find myself listening at lower and lower volumes for fear of annoying anyone. It's a concrete building but I can feel the vibrations through the floor when I listen at normal levels. I have tried to dampen it by putting foam in the ports at the bottom of the speaker but it has no affect, I don't know if I'm just not using a dense enough material or if it's just not going to help. Has anyone ever managed to tame low end in a similar speaker?

As much as it would pain me to do so, I'm considering swapping the Lalis for smaller stand mount speaker that I could enjoy at normal volume. I don't see myself living in a property where the Lalis could do their thing anytime soon. I don't listen to music particularly loud but I am finding it almost too quiet to enjoy now. No point in owning them if I can't appreciate them.

As always, any suggestions or comments would be much appreciated.

Cheers

Rich.

yup, its as well to consider those around you as long as its mutual. I made my own to achieve a lower bass output, as im not that keen on it anyway.. but even then the bass does travel even at lower vol. you have solid walls so it should be achievable. maybe some nice full rangers

There is no quick or inexpensive way to reduce low frequency leakage to adjacent properties. Doing so requires extensive structural work and typically the creation of secondary walls or floors. A first step is to talk to your neighbours to establish the extent of the problem and the degree to which the leakage affects them. If it is a significant problem then a change of speakers is probably necessary. Ideally, you will find a speaker that sounds lively at "lowish" listening levels.

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Originally Posted by struth

yup, its as well to consider those around you as long as its mutual. I made my own to achieve a lower bass output, as im not that keen on it anyway.. but even then the bass does travel even at lower vol. you have solid walls so it should be achievable. maybe some nice full rangers

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That's my thinking too Grant, my neighbours are a polite and quiet bunch on the whole. The floors are concrete but the walls seem pretty thin. I don't hear anything disturbing from them so I'm keen to do the same.

I couldn't be happier with how my set up sounds, it's maybe just not right for where I am.

Do you know if the neighbours have a problem with it? You can feel vibrations in the floor but that doesn't necessarily translate into the neighbours hearing the bass at a level loud enough to be annoying.


Try some vibration absorbing something under the speakers if you haven't already.


In any case they live in a block of flats, neighbour noise, including music is to be expected unless it is at unsociable hours. Legally I think that is 0800 to 2300. Personally I don't have music on before 1100 or after 2200 but I think in between is reasonable. Don't forget it's your God-given right as an Englishman to be able to listen to your music. :)

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Originally Posted by Sherwood

There is no quick or inexpensive way to reduce low frequency leakage to adjacent properties. Doing so requires extensive structural work and typically the creation of secondary walls or floors. A first step is to talk to your neighbours to establish the extent of the problem and the degree to which the leakage affects them. If it is a significant problem then a change of speakers is probably necessary. Ideally, you will find a speaker that sounds lively at "lowish" listening levels.

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It's a rented property, so that rules structural changes out.

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Originally Posted by Macca

Do you know if the neighbours have a problem with it? You can feel vibrations in the floor but that doesn't necessarily translate into the neighbours hearing the bass at a level loud enough to be annoying.


Try some vibration absorbing something under the speakers if you haven't already.


In any case they live in a block of flats, neighbour noise, including music is to be expected unless it is at unsociable hours. Legally I think that is 0800 to 2300. Personally I don't have music on before 1100 or after 2200 but I think in between is reasonable. Don't forget it's your God-given right as an Englishman to be able to listen to your music. :)

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It's never late or early, usually just evenings. It is a good point to make that I should actually speak to them first. I think it's because I had an an obnoxious inconsiderate neighbour a few years ago when in was living in Bristol that keeps me from wanting to be the same without realising I'm doing it. I think what I'll do is put music on at a level I enjoy and pop down to speak to them.

There is a chance that the reason you don't hear any noise from your neighbours is not because they are quiet, but because the walls/floors are doing a good job insulating the sound. I would agree with Geoff - first step is to have a chat with your neighbours (while playing some music at a level you are happy with), and see what they say.

I'm sure it can't be as bad as my mum's old house. When I used to visit Friday's, and Bruce's "Play Your Cards Right" came on telly, I could hear the old feller next door shouting "Higher! Higher!....You silly sod, I told you to go higher!" Now that was bad.

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Originally Posted by Pigmy Pony

There is a chance that the reason you don't hear any noise from your neighbours is not because they are quiet, but because the walls/floors are doing a good job insulating the sound. I would agree with Geoff - first step is to have a chat with your neighbours (while playing some music at a level you are happy with), and see what they say.

I'm sure it can't be as bad as my mum's old house. When I used to visit Friday's, and Bruce's "Play Your Cards Right" came on telly, I could hear the old feller next door shouting "Higher! Higher!....You silly sod, I told you to go higher!" Now that was bad.

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That's what the place in Bristol was like, I never heard a peep when a single woman lived next door, she worked in the evenings so we didn't cross at home much. Then one day I heard what sounded like a spoon hitting a bowl from next door, and I thought I must have misheard it as it was crystal clear. But when the quiet neighbour moved moved out and the obnoxious git moved in it turned out the walls were actually that useless, I could hear music, conversation and arguments (and even worse, shagging). I mentioned it politely several times, I even spoke to my landlady about it, but it turns out he was her business partners son so I was f&#ked. I moved out within weeks.

Ive someone on one side of me. The walls are fairly poor, but he can be noisy. water pipes and charging up and down stair etc. I dont know why folk cant climb stairs quietly. its not difficult... mind you he is care in the community so its difficult do communicate

I think you need as others have said, to assess the situation and politely ask if your music is, audible or a nuisance, ideally by setting levels in your home and seeing what it is like for your neighbours. This is a considerate stance.

If it is travelling through the floor, heavy carpet or rugs may be of help.

I don't see rugs/carpets being very effective, they would be more effective at soaking up the higher frequencies. Whereas bass is no respecter of walls and floors, regardless of room treatment. The only effective remedy for that would be an added layer to what you have, with an insulated cavity. Effectively a 'room within a room', but obviously out of the question in a rented property.

Decoupling the speakers from the floor as much as is possible may be your best solution.

As a test you could try plugging the ports quite tightly with socks or t-shirts and see if this works better than the foam.

I meant as a 'panel damper' as in loudspeaker panels, the panel being the floor, but if it is concrete then a larger mass of damper would be required really.

It seems to me to be unlikely that the bass is air transmitted.

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Originally Posted by Pharos

I meant as a 'panel damper' as in loudspeaker panels, the panel being the floor, but if it is concrete then a larger mass of damper would be required really.

It seems to me to be unlikely that the bass is air transmitted.

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Surely the majority of bass energy emanating from a speaker is "airborne" (i.e. a soundwave).

Cabinet borne energy is likely to be concentrated in a narrower frequency band and may excite particular room resonances. Unless there is a major problem with the speaker design and construction these resonances are surely outweighed by airborne energy.

It is difficult to see how the sound can travel to other flats if airborne rather than mechanically transmitted or conducted.

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Originally Posted by Pharos

It is difficult to see how the sound can travel to other flats if airborne rather than mechanically transmitted or conducted.

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When the bass energy from the driver units reaches the room boundaries, then a proportion of that energy is absorbed by that surface. This is turn is transmitted outside of the room. The walls effectively become "sound panels"

I am fortunate enough to live in a detached house and to have one room as a dedicated music room. Even when playing music quite loud, the "leakage" is far greater to adjacent rooms than it is to the room below despite the fact that my speakers are floor standing units.

Low frequencies will transmit through the wall or floor more easily because they have a longer wave length so travel a shorter distance in and spend less time inside the wall.

Hello Rich

If the floors are solid re-enforced concrete then sound transmission through it is not likely to be much at all. Unless the floor had a resonant frequency in the normal hearing range not much is likely to get through. Obviously the thicker it is then the more it will dampen noise. Depending on how old the apartments are the it is also likely there will be some form of heat insulation directly under flooring before you hit concrete, this will also sound deaden further.

One thing you could try is to put some music on with a reasonable low end content and set the volume to an average of 80dB, you can get a free sound pressure meter for you mobile phone to measure it. Then pop down stairs and stand outside the flat below you and see if you can hear much if anything. You could do the same with the flat above, and outside yours.

80dB is a reasonable average listening level, much above this and you are entering into hearing damage areas after 2-3 hours listening. If you know your neighbours you could ask them, but this might provoke an issue when there really isn’t one.

One issue I am very aware of in blocks of flats is that service ducts with cable and pipes running up and down the build can act as sound transmission tunnels. In the 70’s I was in a 17 storey hall of residence in London that had this issue and it was appalling for noise, you could here muffled conversations from rooms many floors below, and if someone had music play it sound like a poor radio in your room. This issue I believe is generally avoided in more modern buildings.

I would check things out before over reacting, and if you have not had complaints then maybe all is ok anyway.

"When the bass energy from the driver units reaches the room boundaries, then a proportion of that energy is absorbed by that surface. This is turn is transmitted outside of the room. The walls effectively become "sound panels""

That is entirely consistent with my thinking that the sound is transmitted via the substrate rather than through air to another flat.

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Originally Posted by Pharos

"When the bass energy from the driver units reaches the room boundaries, then a proportion of that energy is absorbed by that surface. This is turn is transmitted outside of the room. The walls effectively become "sound panels""

That is entirely consistent with my thinking that the sound is transmitted via the substrate rather than through air to another flat.

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Sound vibrates the molecules in the wall the same as it des the molecules in the air - is my understanding anyway. So airborne and structure borne transmission are essentially the same thing.

This is why we continue to dither about 'downsizing' from a house to a flat. We have good thick walls, and relatively quiet neighbours, and remember back when we lived in a flat. The woman above us seemed to be permanently hoovering, whilst the woman in the flat next to us played opera very loudly all day and well into the night. She was a bit crazy, and had barricaded the way to her door with bins and cardboard boxes to hinder people from complaining to her about the noise. And we lived on the ground floor. Imagine having noisy neighbours above and below you!

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Originally Posted by Macca

Sound vibrates the molecules in the wall the same as it des the molecules in the air - is my understanding anyway. So airborne and structure borne transmission are essentially the same thing.

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Of course. but the difference in audio terms is that we want the acoustic energy to pass to our ears through the air, but don't really want that energy to subsequently escape from our listening room through the materials that form the room boundaries!

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Originally Posted by Joe

This is why we continue to dither about 'downsizing' from a house to a flat. We have good thick walls, and relatively quiet neighbours, and remember back when we lived in a flat. The woman above us seemed to be permanently hoovering, whilst the woman in the flat next to us played opera very loudly all day and well into the night. She was a bit crazy, and had barricaded the way to her door with bins and cardboard boxes to hinder people from complaining to her about the noise. And we lived on the ground floor. Imagine having noisy neighbours above and below you!

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i got offered a modern flat down rd from me by the housing association as i am disabled.. I said over my cold, dead body ;) couldnt stand having so many folk around me. Ive only one neighbour with a connection to house. am an end terrace with driveway and big garden, plus good neighbours bar the connecting one.

Well, I put a fairly bass heavy tune on and had the music at a level slightly louder than I would normally, which was high 60s dB (thank you for the tip Adrian). I popped downstairs to speak to the neighbour below me, he said he couldn't hear a thing and never has, result! I asked if he could hear the bass thump and he said not at all. He did comment on how considerate it was of me to ask, I'm glad I did as it's more enjoyable to listen to music without worry.

All's well that ends well.

Thanks to all for your input, it was much appreciated

Rich.

Good news.

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Originally Posted by stairpost

Well, I put a fairly bass heavy tune on and had the music at a level slightly louder than I would normally, which was high 60s dB (thank you for the tip Adrian). I popped downstairs to speak to the neighbour below me, he said he couldn't hear a thing and never has, result! I asked if he could hear the bass thump and he said not at all. He did comment on how considerate it was of me to ask, I'm glad I did as it's more enjoyable to listen to music without worry.

All's well that ends well.

Thanks to all for your input, it was much appreciated

Rich.

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Great to hear :lol:, 60-70dB is normal, human speech normally peaks around 75dB, So if you set it to peak at 75dB you will be fine. Pleased to hear it has worked out.

Yes,great result! It's good to be considerate of your neighbours.
I have no problem with mine.They even throw bricks through my windows so they can hear it better!

:lol:

I found first generation air inflated Townshend
audio seismic sinks to be excellent at decoupling speakers from floor. I used them on wooden floors.
When spiked to floors, the bass would rattle the floors and I could feel it in my feet. Using sinks, all the vibration was absorbed and nothing transmitted to floors. Appreciate concrete is different to timber so effect may be different.
Graham

"Sound vibrates the molecules in the wall the same as it des the molecules in the air - is my understanding anyway. So airborne and structure borne transmission are essentially the same thing. "

Yes Martin, but we are discussing which route the leakage may be through, and the curative treatment is appropriate to that route.

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Originally Posted by Pharos

"Sound vibrates the molecules in the wall the same as it des the molecules in the air - is my understanding anyway. So airborne and structure borne transmission are essentially the same thing. "

Yes Martin, but we are discussing which route the leakage may be through, and the curative treatment is appropriate to that route.

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The curative treatment is the same either way - you need a very thick, very dense boundary between the source of the sound and the person you don't want to be hearing it! Or a vacuum. But that's even harder to achieve.

These modern apartment buildings have pretty thick concrete walls and floors between the flats though so I'm guessing that is working well in this particular situation. I had the same experience years ago living in an end terrace, saw the neighbour out front and asked her if the music was a bother, she said she had never heard me play any music. After that it was party time!

I disagree. If the sound is travelling through air, (compression and rarification of that air), it will be prevented from exiting the source room by sealing, and constraining that process from reaching and entering the receiving room.

If it is travelling through the subststrate, this substrate must either be restrained from movement, (bracing in the case of a cabinet), or more realistically, absorbed somehow from that substrate. In the case of speaker cabinets heavy absorbing layers are applied to the internal surfaces, but it is difficult to see how this could be done with a wall, a 6" thick rubber 'sheet' glued to the walls perhaps. :(

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Originally Posted by Pharos

I disagree. If the sound is travelling through air, (compression and rarification of that air), it will be prevented from exiting the source room by sealing, and constraining that process from reaching and entering the receiving room.

If it is travelling through the subststrate, this substrate must either be restrained from movement, (bracing in the case of a cabinet), or more realistically, absorbed somehow from that substrate. In the case of speaker cabinets heavy absorbing layers are applied to the internal surfaces, but it is difficult to see how this could be done with a wall, a 6" thick rubber 'sheet' glued to the walls perhaps. :(

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Sorry you are not quite right as concrete is a pretty solid and inert medium, yes it will vibrate but will need significant force to do so. I used to work in a sound and vibration lab at Southampton University. The two anechoic chambers (echo boxes) where about 25' by 25' by 25' and the walls, ceiling and floors were about 18' thick re-enforced concrete, they had huge steel doors which were filled with serious sound deadening material and had a latching mechanism to seal them shut them air tight to very efficient triple seals all around the edges. I remember we tested several ships horns and these were putting out in the region of 130dB at full blast, measured inside the chamber with a wired up microphones. Outside the chamber even with 130dB running the maximum level we read to check on safety was around 75dB, so the concrete walls had a significant deadening effect. You have to remember that 130dB is an extremely loud noise, and if you were subjected to it then it would be end of your hearing pretty quickly. So for the concrete soak up that much energy and to lower the sound pressure level by nearly 50% is a huge change.

Please can you show me my error in thinking Adrian?

This may seem arrogant, but I think that in principle, I'm right.
I of course bow to your superior experience and knowledge, and am surprised that the sound was not attenuated more then 55dB.
How did that sound get out? Yes "the concrete walls had a significant deadening effect" but were not 100% rigid, and hence non vibrating, and 'conducted' some sound. The doors and seals also were not perfect seals, the doors will also flex to some extent, and some air will also pass through the non perfect seals; transmission through air.
If the walls do not move at all, then surely any transmitted sound must be via air.

I know about high spls, because I have just won a legal case against BT for them subjecting me, amongst others to headphones producing up to 131.5dB.