Print Page | Close Window

harder bump when hot?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=105213
Printed Date: May 04, 2024 at 7:24 AM


Topic: harder bump when hot?

Posted By: slickthellama
Subject: harder bump when hot?
Date Posted: June 02, 2008 at 11:35 PM

Has anyone ever noticed subs seem to hit harder when it's really hot out? I think it may be due to the rubber around the edge of the sub being more maleable due to higher temps. ALso, my buddy said something to me once about how there is some oil that makes subs hit harder when cold, has anyone ever heard of this oil?



Replies:

Posted By: Alpine Guy
Date Posted: June 03, 2008 at 6:21 AM
Yeah, it's called snake oil. But no, really, your friends on crack, get an alarm otherwise he will steal your stuff to sell it and get more crack!

I believe the perception of your subs being louder will have more to do with the air density and humidity in the summer months more than anything.

-------------
2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.




Posted By: daboss593
Date Posted: June 03, 2008 at 7:18 AM
lol errrrrrr never heard of that one. an old timer thats showing me the ropes did say. after a sub is broke in it would perform slightly better?

-------------
OWWWWWWWWWWW you said you discharged the cap!




Posted By: slickthellama
Date Posted: June 03, 2008 at 3:52 PM
Characteristic impedance
Acoustic impedance of air at different air temperatures and at 1 atm Temperature Influence
°C      c (m/s)      ρ (kg/m³)      Z (Pa·s/m)
−10      325.2      1.342      436.1
−5      328.3      1.317      432.0
0      331.3      1.292      428.4
+5      334.3      1.269      424.3
+10      337.3      1.247      420.6
+15      340.3      1.225      416.8
+20      343.2      1.204      413.2
+25      346.1      1.184      409.8
+30      349.0      1.165      406.3

The characteristic impedance of a medium, such as air, rock or water is a material property:

    Z_0 = \rho \cdot c \,

where

    Z0 is the characteristic acoustic impedance ([M·L-2·T −1]; N·s/m3 or Pa·s/m)
    ρ is the density of the medium ([M·L−3]; kg/m³), and
    c is the longitudinal wave speed or sound speed ([L·T −1]; m/s)

The characteristic impedance of air at room temperature is about 420 Pa s/m. By comparison the sound speed and density of water are much higher, resulting in an impedance of 1.5 MPa s/m, about 3400 times higher. This differences leads to important differences between room acoustics or atmospheric acoustics on the one hand, and underwater acoustics on the other.

https://en.wikipedia.org/wiki/Acoustic_impedance




Posted By: Alpine Guy
Date Posted: June 03, 2008 at 5:14 PM
So it looks like sound travels faster in the warmer temps because the resistance of air is less, but at the same time it's heavier? lol

-------------
2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.





Print Page | Close Window