Home Theater Forum and Systems banner

1 - 6 of 6 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hi All,

I am confused with the difference between Acoustic Treatment and Noise Curve. If I want to make my room flat, for example 20dB, do we measure it with Acoustic Treatment or Noise Curve? Are they same? Please help. I'm not an expert and newbie. Thanks before.

Budhi
 

·
Registered
Joined
·
486 Posts
Acoustic treatments (physical objects) are used to treat things like reflection points and absorb other unwanted characteristics that are impacted by a room. Eq's are applied (electronically) to "noise curves" when acoustic treatments can not or don't totally fix an audible issue with a "noise curve". For example, very low frequencies which would require very very large acoustic treatments that cannot be placed in a room.

Hope that is clear as mud. :huh:
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
Does it mean if I want my room get 20 dB with acoustic treatments = Noise Rating Curves 20 dB?
 

·
Registered
Joined
·
34 Posts
NR curves are used when we are talking about background noise in studios or control rooms for example. This noise may come from HVAC and curves follow ears sensitivity. They are used as a design criterion. Acoustic treatment is related to background noise in a way that absorption can lower rooms decay time and this way background noise, but it's effect is quite minimal.
 

·
Premium Member
Joined
·
1,562 Posts
20 dB is very low, is this a listening room, or studio, or anechoic chamber? :)

It's great to have a very quiet listening room. Most of us do not have that situation. We can measure the room noise floor with REW using no signal. It's a measurement of how quiet the room is. We can thus use REW to try to detect the results of any changes we make to the room that are intended to improve how quiet it is. 20 dB sounds extremely low however and probably only possible with a very special room construction. I think, the inexpensive measurement mics most of us use have a noise floor that is higher than that (maybe 30 dB) so we would not be able to even measure a noise floor that low.

The noise in all typical listening rooms rises toward the low end so that is the hardest area to control. On the practical side however, it is hard to hear LF (low frequency) noise unless it is much higher in level so it does not need to be as low as the higher frequencies.

I would recommend that in the end you just use your own senses to decide when the room is quiet enough to hear the soft music details. Try the acoustics forum more specific targets if this is not the general information you were looking for regarding noise floor.

This noise floor is different from the speaker/room response we measure using REW test signals. The room plays havoc with the LF SPL response of the speakers so we use EQ to smooth the LF response at the LP (listening position). This improves the overall sound accuracy at that position. We normally do this using a REW test signal that is adjusted to someplace around 75 dB.
 
1 - 6 of 6 Posts
Top