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View Full Version : Peak @ 42hz but sweep is 52hz!?



frkkevin
11-29-2006, 08:37 PM
Ok.. I'm not sure what this means exactly. My box is tuned to 35hz but peaks at 42hz. When I run a sweep it says my note is 52hz, but that is incorrect. Does this just mean that my car peaks around 52hz and I need to tune my next box to 42hz?

Trying to break a 150dB here.. 146.3 @ 42hz just is not cutting it for me..

davesexplorer
11-29-2006, 08:39 PM
With your box/subs everything in the car and playing, it could all be resonating together peaking at 52 hz. If it was on a T/L you could see what frequencies are doing what.

matrxx dude
11-29-2006, 08:41 PM
did you run the sweep on a term?

frkkevin
11-29-2006, 08:45 PM
Yes it was all a TL.. but when I burped at 52hz my score was dramatically lower than at 42hz.. Before I resined my box and did a double baffle my box peaked at 45hz.. and the sweep matched. Now after those mods the sweep is 10hz higher than where I actually peak.. confusing to me

matrxx dude
11-29-2006, 08:47 PM
did you run the sweep at pretty high volume,because if you did not,the sweep peak will be off.

frkkevin
11-29-2006, 08:52 PM
I see.. I normally run my sweep at 18 (burp at 26) so I can save my charging system.. think that is why it was off?

Btw.. know any information for a 2003 Jetta.. about where it peaks. If I could ge that info it would save me a hell of a lot of trouble :)

Chevyaudio
11-29-2006, 08:54 PM
Yes the volume difference made the change...Also are your the kid from the TBP shows...If so, Im the guy that had the BTL 12" there...I was working on the Xtera with the 2 DD9515s and 40.1

matrxx dude
11-29-2006, 08:54 PM
i know in my explorer you have to run the sweep pretty high to be accurate on the burp,what hertz is your top number coming from.

frkkevin
11-29-2006, 09:10 PM
42hz .. yeah I'm the one competing in TBP org.. I'm on a quest to break that 150. I was going to try to do it with the single sub setup I had but I'm just gonna toss in another 35.1 and SX 15" ... :)

Chevyaudio
11-29-2006, 09:11 PM
Good Luck, breaking a 50 in a trunk is an accomplishment.

matrxx dude
11-29-2006, 09:14 PM
well 42 is your resonant freq.

billabongcr
11-29-2006, 09:15 PM
Btw.. know any information for a 2003 Jetta.. about where it peaks. If I could ge that info it would save me a hell of a lot of trouble :)

i peaked in the backseat of my exgirlfriends :naughty:

Chevyaudio
11-29-2006, 09:18 PM
well 42 is your resonant freq.

Im pretty sure the resonant frequency of the Car is alot higher than 42...thats just where his current setup is peaking at.

If I were you man, I would build a box that brought your note up into the 50s maybe around 52-54. You should see a gain in a trunk car...of course it wouldnt sound as good as a daily box, but you would get louder on the mic.

frkkevin
11-29-2006, 09:18 PM
lmao.. I think I can do it.. With my current setp doing 146.3 .. adding 2 of everything I had.. another 1500rms.. and another SX 15.. in theory that is a 6dB gain but I'm hoping to see at least 4dB..

Chevyaudio
11-29-2006, 09:20 PM
Yeah...the ol' double power double cone area adds 6db doesnt work out all of the time.

do you have the electrical system to back up 2 35.1s

frkkevin
11-29-2006, 09:25 PM
pfft.. not yet :) .. current setup is 1/0 for all the wiring.. ground, power, big 3 .. two optima yellow tops .. and the puny stock 90A alt

the electrical upgrade will come after I have the equip

Chevyaudio
11-29-2006, 09:27 PM
in my opinion I would do the electrical first...Most important part.

frkkevin
11-29-2006, 09:31 PM
if i could find a decent priced alt i would.. irragi is too expensive.. $400 for a 200A .. a 1/3 of the cost i could get an OEM alt and just run two for 180A