posted
Any one have a general idea if this is true? Was told cold weather and lack of humidity can rob spl. I have a diff set up then what I had in last summer so will have to wait a few months to know for sure.I know last year even from Qualifying early mornign then final runs later in afternoon would be lil diff due to higher heat and change in humidty. Every one has there theorys tell me yours.
posted
depends what you are tuned for... Testing at home in Canada with lower humidity and higher elevation I was burping at 58hz... In california my note changed to 62 or 64 hz just from the 50% boost in humidity and the drop in elevation.
posted
I use a 47 hz tone here in Pa in normal weather. I went to Niagra Falls in a snowstorm and my note change to 42 hz on saturday. The storm cleared on sunday and my note then changed to 46 hz. All the same SPL. 150.4 dB, no change
So it all depends on the car and your setup. test test test. and then test again
-------------------- Ed Lester, Team T3 Audio Team Maxxsonics Team Kinetik Team Hooker Audio Team Second Skin Team RazorLite 3 time dB drag World Finalist. 2003, 2005, 2007 electronic engineer acoustic engineer physics major humble guy
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Posts: 1554 | From: near Philly Pa | Registered: Dec 2006
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posted
Sound moves quicker through colder air than warm air. When the air becomes warmer the molecules become closer together and when colder spread apart. From what I've always seen spl is better in colder weather for me. One comp I went to morning qualifying was at 10am and did 158.9 and later in the day during elimination rounds we did 157.5 at about 2pm in the afternoon. This was in Carlisle PA back in May of 2001. There was probably a 20 degree difference between morning and afternoon thus hurting our overall spl.
-------------------- Team Sundown Posts: 827 | From: North Carolina | Registered: Jan 2008
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posted
^Not to mention all the circuits, being colder, will have better conductivity and electronics will (in general) work better..
But as dtbrown mentioned...batteries wont perform as well...so im not too sure, to be honest..
-------------------- Creator-Ohio Bass Society
First and only dual-alternator Saturn on the planet Sub and sub amp: 18" Fi BTL fully loaded, fed by a SoundStream XXX10000 Handmade custom bracket replacing AC with 250 amp alt 225 amp alternator in stock location (custom bracket) Batteries: Trunk-(2) XS Power D3100's 4 power+4 ground 0-gauge runs to rear Posts: 611 | From: OH | Registered: Apr 2007
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quote:Originally posted by dtbrown: Cold batteries will no deliver as much amps as normal temp batteries.
That's strange because my voltage always reads higher when it's cold outside as opposed to warm out. Why if the voltage reads higher would the batts perform worse?
-------------------- Team Sundown Posts: 827 | From: North Carolina | Registered: Jan 2008
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posted
what is cold to you? bc anything under 20 deg fer. aledgidly your battery only has 30% of cranking amps. Yes your voltage im sure reads real close to same but acutal output is lower.depend on where you live every ones definition of cold is diff.
The main part of this thread was I was curious if cold weather affects actual spl. I did not no it could affect tuning.
posted
how are molecule closer together in the heat than cold if i am not mistaken the hotter the air the more energy the the farther apart the molecules the less dense the air is the more miosture the air can hold too.
ideal gas law
PV= nrT
-------------------- atomic apoc 15 with spl mod and a atomic 1500.1 at .5 ohm
posted
I'm better in the cold than the warm. About .2 db higher in the evening vs afternoon
--------------------
2003 World Finals S.S. 5+ 8th 2004 World Finals S.M. 3-4 5th 2004 MECA World Finals M5 4th 2004 MECA World Finals MR5 4th 2004 MECA World Finals DB5 2nd 2005 World Finals S.M. 3-4 8th 2007 Ext 1 Not done in time 2008 Ext 1 169.5db certified and climbing
quote:Originally posted by dkmst23: how are molecule closer together in the heat than cold if i am not mistaken the hotter the air the more energy the the farther apart the molecules the less dense the air is the more miosture the air can hold too.
ideal gas law
PV= nrT
Do some research, you'll see that I'm right.
-------------------- Team Sundown Posts: 827 | From: North Carolina | Registered: Jan 2008
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quote:Originally posted by dkmst23: how are molecule closer together in the heat than cold if i am not mistaken the hotter the air the more energy the the farther apart the molecules the less dense the air is the more miosture the air can hold too.
ideal gas law
PV= nrT
Or wrong, either way I'm still louder at colder temps. So, I guess unless someone does a study on spl in cold or warm temps we'll never really know. I have read sources that suggest the travel of sound is greater in warm air, but we all know that sound and spl are two different things. One is an audible noise, and the other is the pressure derived from said noise. You are right about the molecules though, I guess I need to reference more credible sources before assuming they are correct. Oh, well if I am wrong shoot me. We still don't have an accurate display of this theory on spl though.
-------------------- Team Sundown Posts: 827 | From: North Carolina | Registered: Jan 2008
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posted
colder air is more dense. Sound travels faster through more dense materials. This changes your note, it only changes dB if you do not adjust for the note change.
at close to 180 dB there is a big effect on humidity, so extreme cars using a big AC are trying to adjust the air humidity as well as temperature.
-------------------- Ed Lester, Team T3 Audio Team Maxxsonics Team Kinetik Team Hooker Audio Team Second Skin Team RazorLite 3 time dB drag World Finalist. 2003, 2005, 2007 electronic engineer acoustic engineer physics major humble guy
3 12" T3 Audio TSS 1 HiFonics XXV Maxximus 3 Kinetik HC 2400s
Posts: 1554 | From: near Philly Pa | Registered: Dec 2006
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posted
my system sounds louder on low music when it's cold, haven't done enough testing to see what's up on frequency. Both with the alternator running, reducing battery performance impact.
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be Zensky....World Domination at It's Finest www.zensky.com Posts: 3269 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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posted
The degree of cold matters too. I've heard guys talk about testing at 75 degrees and hitting a good number, then testing again with all the same settings but at 50 degrees and getting worse, then testing again with the same settings at 40 degrees and getting better. I know humidity and elevation play a part in it too. As does the temperature and what the enclosure is made of too. Thats all left to testing in each persons vehicle though, probably won't be the same in everyones ride.
quote:Originally posted by dtbrown: Cold batteries will no deliver as much amps as normal temp batteries.
Bang on, I also would like to add the suspension on the sub will be less efficient at lower notes and with higher Q it won't sound as good.
So the battery and sub are both affected by the cold otherwise the cold isn't that bad on your score. Humidity also plays a part but each vehicle setup is to different to make a guess on whether that has an effect in your situation.
posted
what kind of fool would hold an SPL contest in the winter
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be Zensky....World Domination at It's Finest www.zensky.com Posts: 3269 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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posted
I just wanted to bring this one back up to ask a ? I know it was discussed here that elevation can play a part on the note played therefore changing spl. I recently did a test from the difference of spl from Ohio to North Carolina. The only thing that I changed in the vehicle was the woofer's spider configuration and a slightly longer coil on the sub. The subs are two stock Sundown Nightshades vs. two Sundown Nightshades with a longer coil and harder spiders. The really big difference I got was that in NC with the upgraded subs my note went from 48hz to 56hz being the loudest. 51-55hz yeilded the same output, but 56hz was one tenth higher than those. My spl changed from using the stock woofers in Ohio with an average of 148.1 to 147.3 in NC with the upgraded woofers. I've only referenced this with one TL so I'd like to do some more testing on another mic to get a conclusive answer. Does anyone think that these slight changes in elevation and the small upgrades in the woofer would have that big of an effect on my spl? This is at least a .8db difference. I may have been able to get some of that back by charging the car up some, but that would still be a significant decrease.
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