Phelonious Ponk
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In August, I'm moving into a small condo with hardwood floors. What is the best thing to put under area rugs for absorption?
Tim
Tim
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What to put beneath an area rug to absorb reflections?
- Thread starter Phelonious Ponk
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I believe a thick rug will be fine,to absorb lower frequencies say sub 500Hzyou would need such thick foam ,you would need to mount a small expedition to get to the HiFi.
Keith.
Keith.
Whatever will let air through. Make the rug and underlayment an inch thick if you can.
I use a beehive rubber pad that also adds a non-slip factor. Inexpensive.
Double layered would be cool if desired.
Double layered would be cool if desired.
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i use about a inch ( once shag pile is on top of two layers of that underlay from link) but what's the significance of that from a acoustic point of view?
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At the risk of stating the obvious, the purpose here is to get rid of the sound waves hitting the floor and getting to your ear. In acoustics 101, we would want to block everything above transition frequencies of a 200 to 300 Hz. That would call for an absorber that is at least 4 inches thick. Here is a simulation of one:
The horizontal scale is frequency and vertical is amount of absorption. And "alpha" if 1.0 means perfect absorption. We see that this 4 inch absorber achieves very good absorption down to 200 to 300 Hz. We call these "broadband" absorbers and it is what you need to use if you deploy absorbers in your room.
A 4 inch absorber on the floor would be problematic of course. Fortunately listening tests show that the coloration that occurs are above 500 Hz. Here is the simulation of a 1 inch absorber:
Good absorption starts around 1000 Hz or so which is fine for this application. A bit thicker would be nicer but not mandatory.
The operating principle here is simple: movement of air molecules is converted to heat. That is why you want the rug and underlayment to be porous. The larger wavelengths cause the molecules to be active well above the rug (highest velocity) so they are not affected by the relative thin rug. So if our aim is to absorb smaller wavelengths/higher frequencies of sound, we don't need as thick of an absorber.
Lol I knew it helped with floor reflections but was totally ignorant as to the significance of the one inch thickness( thicker was wider frequency range I knew), Frequency range covered etc..But no longer! Thanks
I might put a extra layer down, as it seems no harm will be done, that is until I trip over my rug
Is there anything non invasive we could do on the ceiling?
At work we install this ( in communal areas , flats/apartment buildings etc) but would I get any advantage from it on my ceiling or else where..,
http://www.british-gypsum.com/products/gyptone-quattro-41
I might put a extra layer down, as it seems no harm will be done, that is until I trip over my rug
Is there anything non invasive we could do on the ceiling?
At work we install this ( in communal areas , flats/apartment buildings etc) but would I get any advantage from it on my ceiling or else where..,
http://www.british-gypsum.com/products/gyptone-quattro-41
For reasons not very clear, ceiling reflections do NOT have the same subjective effect as the floor. As such, it is not as important or necessary to absorb them. One strategy is to put a diffuser there to send the sound waves to left and right walls to create more spaciousness. But again, not strictly necessary.
Keith_W
Major Contributor
Amir, if I am not mistaken, the effectiveness of absorption depends on two things: (1) the density of your absorbent material, and (2) the thickness of the material with relation to the wavelength you want absorbed. If the material is too dense, it will simply reflect the signal. If the material is not dense enough, it will pass the wave through with very little attenuation until it encounters a more dense surface and reflects.
I point this out because i'm not sure if your model takes into account the density of the absorbent material?
In most homes, ceilings are made of much thinner material than floors. In my home, the floor is hardwood which rests on a concrete slab. The ceiling is plasterboard, suspended from an internal frame made of wood. Low frequencies just pass right through it.
I point this out because i'm not sure if your model takes into account the density of the absorbent material?
In most homes, ceilings are made of much thinner material than floors. In my home, the floor is hardwood which rests on a concrete slab. The ceiling is plasterboard, suspended from an internal frame made of wood. Low frequencies just pass right through it.
It does actually. It is one of the parameters in there. Alas, it is impossible to have the measurements for rugs and such.
A large bear skin run might be just the thing. It could also do double duty on those nights when the fireplace is burning and Frank is singing softly in the background.
I will send you mine to try
On a more serious note a while back I had a idea and so far can't find any company that's doing it...
Acoustic furniture, so you measure your room send results and they make you a sofa or whatever that will be benifcial to you in your room.
Just imagen having all the volume afforded by a sofa to play with and ultimately tune the effect to the customers room. Or having a coffee table that because the wife insisted it must be right where you don't want it you now need the least acoustically damaging option.
This could be complimented with style not just function to include all sorts of furniture. For me personally it would be great to have a kitchen designed with my room acoustic in mind, then I could get rid of the partition wall in my listening room.
The problem with that idea is that you would want the sofa in pink zebra color and no else would. So the business does not scale.
Yea and you would want each seat to have a picture of the individual members of 'the village people' so you could sit on a different one every day of the week!
That's why it's so important for you to have great bass response in multiple listening positions.
I wonder though... What seat would you wear out first?
And yea you will be needing the anti spill coating...even though it might be acoustically compromising .
ROTFLMAO, Good one Amir
Hey thinking about it, I want the village people one too...
At this rate, I will be sitting on the rug, thank you very much!
At this rate my rug will be higher than my sofa anyways .
If you sit on the rug you can 'admire' all the guys at the same time! You are always one step ahead of me amir
dallasjustice
Major Contributor
I'm not sure what you a referring to here.
For me, the thing I'm most interested in mitigating from the floor is the Allison effect "null" from that reflection. Most rooms have the same effect from the floor and the ceiling. It's just at different frequencies because they are the same distances from the speakers.
Maybe you aren't talking about that. Maybe you are talking about the higher frequency reflections; vertical off-axis performance of a speaker is less important than lateral off-axis. I get that. But there's still going to be a ceiling reflection which causes a "null" at the seated position in most rooms. I don't recall reading anything which says that the ceiling Allison effect is any less audible than the floor Allison effect.
Maybe it's a less strong reflection because it's further away. But it's still there.
