85dbc what would the level be at 15 meters if inside the room?

[JBL 4645]

I noticed a defused low bass drum and beat rave music coming from near. I looked out the common hallway window and noticed it was bunch of young kiddies in their 20 years playing loud RAVE music with those gustily one beat notes!

The SPL db was 85dbc from the window the distance was about 15 meters to the room I would say. So question what is the actually rough level would it be 100 dbc inside room, because I noticed neighbour calmly walking by the flat and buzzing the flat and knew the neighbour wasn’t too happy,

Also their window was wide open to advertise the rubbish music they where playing.

“Can you please turn the bass down I can’t hear the TV”

One of the kiddies leans out the window and apologizes with and “England is playing today its half time”.

I’m not even watching the world cup myself.

Anyway the neighbour walks back to his flat and they turn it back up to 85dbc from the window distance that I was measuring it at. Cheeky buggers! Then they turned it down to below 80dbc and lower.

I know the dimensions of these buildings and issues regarding sub bass “nodes” within the living rooms as it takes more than one sub to flatten the sub bass out for equal smoothness. One note bass on rave is usually around 50Hz range maybe a bit of 60Hz range with the same boring low tone.:barf:

[toddalin]

Well, seeing as no one else would help, I find that you've not provided enough information to make the calculation.

Ignoring frequency (makes a big difference), some sound radiates through the wall while some comes out the window. For what comes through the wall.

Lw(wall) = Lp(outside) +10 log A(wall) - 10
Where:
Lw(wall) = the attenuation due to the wall,
Lp(outside) = SPL outside at the given location
A(wall) = the wall area in square feet

Then we need to consider what comes though the window (hole in the wall).
Lw(hole) = Lp(inside) + 10 log A(hole) - 10
Where:
Where Lw(hole) = the attenuation due to the hole,
Lp(inside) = SPL inside at the opening
A(hole) = the area of the opening in square feet

So, we need the wall materials and size, and size of the windows to make the calculations.

[jcrobso]

Evey time you double the distance from the source to the listener the level decreases by 6db. Your at 15 meters at 7.5 meters the level would be 6 db higher, or 91db. At 3 meters the level would be 6 db higher or 97db at 3 meters from the window. I'm guessing that inside the room the level was way over 100db.

[JBL 4645]

Evey time you double the distance from the source to the listener the level decreases by 6db. Your at 15 meters at 7.5 meters the level would be 6 db higher, or 91db. At 3 meters the level would be 6 db higher or 97db at 3 meters from the window. I'm guessing that inside the room the level was way over 100db.

Well I’ll go with that and wow this thread as been stuck up on the top of the page for 1 week! Wow at least one of you guys responded.

I have no idea if they where running a PA system because it had that tone like sound on the lows. But like I said, it was most likely around the 50 to 60Hz range. I couldn’t listen to that type of music for 1 minute even at 60dbc.

Also the wave length of frequencies lows have certain distance that they can travel, yes?

I could hear the lows when I was walking down the road some 200 plus feet away. When I was walking back from the shop I could hear the lows’ was reflecting off the building opposite on the other side of the road.

Only I know where the location source was. If I had just come back from town without knowing I would have been confused as too where it’s coming from. It just bounces off every hard wall and echoes around.

Well Cheers jcrobso, toddalin for the reply. :)

[jcrobso]

Low frequencies require moving so much air that they tend to keep going!:eek:

[JBL 4645]

Low frequencies require moving so much air that they tend to keep going!:eek:

Yes but at some point they have to dissipate though the air. They travel further still though warm water. But we are not in the water are we. :D

[Akira]

Some Madame Butterfly @ 120db should do it!

[Chris Brown]

Reminds me of this 4th of July. Somehow I got away with playing my music extremely loud at like 10-11pm at night. Meter said 133dBC in my room, though I have no idea how loud it was outside that night. My amp has been measured putting out 380wpc @ 4ohms and I was putting it ALL to use that night. Cops are always too busy with fireworks to deal with Noise complaints on the 4th :)

[JBL 4645]

Well there’s really not much that can be done about it over here. The fuzz are powerless to deal with it even at 3am at night! Someone was having a party across the road last year that ran till I think from 11pm up to 4am!

The windows where wide open to advertise it to the whole neighbourhood as the sound is bit audible at late night over the stillness of road traffic noise.

I think I heard fireworks a few nights back around 10pm as Bournemouth pier has little firework display that lasts 10 or 15 minutes. It lasts for a few months around peak summertime.

[Steve Schell]

Jcrobso's comments are correct for an expanding spherical (or portion thereof) wavefront, where the area is growing steadily. If the area of the wavefront is constrained to a smaller area, such as by a hallway, then the attenuation over distance might be less. Depends on the resistance of the structures to the passage of low frequencies; my neighbors would probably testify that my house does not contain them very well. I don't listen to rave music, though I do give the Bass Outlaws a spin now and then.

[JBL 4645]

Jcrobso's comments are correct for an expanding spherical (or portion thereof) wavefront, where the area is growing steadily. If the area of the wavefront is constrained to a smaller area, such as by a hallway, then the attenuation over distance might be less. Depends on the resistance of the structures to the passage of low frequencies; my neighbors would probably testify that my house does not contain them very well. I don't listen to rave music, though I do give the Bass Outlaws a spin now and then.


http://www.youtube.com/watch?v=wM-yf6x8g0Q

I’d have to turn on the system and look a this on spectrumlab as I have no idea how low this goes down too?

[JBL 4645]

Well no offensive Steve that was like listening to wall full of wet paint drying! :p

I could only listen for few minutes I wasn’t sure if the video was stereo or duel mono over LCR what a load of hog wash!

What Simon Cowell think of this track?
http://t3.gstatic.com/images?q=tbn:n1NrFsCXl-eiNM:http://neilbeynon.files.wordpress.com/2007/12/simon_cowell.jpg
It felt like my organs was going too exploded under a bad Indian beef curry.

[Eaulive]

46653

Lowest note in that track is 36Hz... for a few seconds, then some passes at 43Hz but the bulk of it is at 48Hz.

Interesting... I kept it to listen to it on a bigger system but I suspect it fits very well the car audio crowd and their "one note wonder" systems :crying:

[Steve Schell]

LOL you guys, I never said it was art! What the Bass Outlaws offers is an absurd, bass line heavy listening experience that gives everyone the grins for a couple of minutes before they beg you to turn it off. The melody line (if you can call it that) is pretty much pure sine wave in a mix that is hard to find anywhere else except an audio generator; the other percussion and vocal sounds are mixed waaay down in level. In the sampled cut the main low note looks to be about 48Hz., but I would direct your attention to their CD "Illegal Bass", cut 8 "Beau's Bass." Here we find a main low note of about 31Hz., and played above 95dB it will modulate your speech. Though crazy, the Bass Outlaws separates the man from boy subwoofers in a hurry, and the booty-licious cover photos are an added attraction.

[JBL 4645]

3:03 I heard a distant echo like male voices that is far as I can listen to this. Sounds like it was filtered on purpose well its not my cup of tea. Oh, I forget I don’t like English tea. It’s not my can of cream soda! LOL