posted
Entered my first SPL event over the weekend and did very poorly, a 129.3 lowest accross ALL classes (best in my class hit 148). I'm runnin' 2-Hott Setup 2.50s bridged mono into 2-Atomic HPW1094 10s in a box built to manufacture specs in a '93 Probe. According to the sponsering shop owner I should have been very competitive in my class.
I went through the lanes using a 40hz tone, right/wrong???
Can anyone give me some pointers on level setting, setup, which hz, ANYTHING that can help get me in the ballpark.
posted
OK first off is the box sealed or ported? Some people may not like what I am about to say but here it is. Go buy a Virtual Technologies box. Do u have an extra battery in the car or caps? A 40hz note is not neccessarilly the note you should be playing. Different vehicles play louder at different notes. You have a hatchback so a VT box will work very well in your car. Make sure polarity on the subs are correct. You should be able to high 130's low 140's with those subs in a VT box. They are amazing boxes. How much power do those amps put out anyway. Might try getting a stronger amp then those Hott Setup amps. Just a thought. There could be alot of factors in your score. I have heard alot that probes score low because of the shape of the car. Just another thought.
------------------ True winners never cheat So that makes Tim a real loser Way to go Tim!! F T M
Posts: 169 | From: Duluth, GA | Registered: May 1999
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posted
The amps are rated @ 200 watts RMS when bridged mono. The VT box could be an option but the sub box I'm usnig now is totaly intigrated in the custom install.
When deciding which freq to use in the lanes is it best to use a sweep gernerator to find the Hz that the car resonates at, then level set the amps using that Hz?
Also, at what % of clip can you overdrive the average amp before you don't get any more SPL?
posted
Just my .02 worth, but any time I have competed in a event using SPL as a factor for score. I see more people hit higher with a 80hz note. I picked a song with roughly 70-80hz variations and with my OLD RF series1 12's I hit 136.9 in a 1986 Nissan Pulsar. Man that was like forever ago. Anyway I have always used the 70-80hz range for my SPL scores and done well.
posted
first of all get a disc with tones recorded @ zero db level as is our favorite db jams disc or the usac disc {the brown one} then just pick a tone such as your 40hz then get a digital volt meter, if you can not get your hands on an O scope, put on about the 20 volt a/c volt scale play your tone @ a low to moderate volume and then adjust your amp gains as even as you can get them, because a little bit of difference @ low volume is a much greater difference @ high volume. The reason to do this at low volume is because your voice coils will heat up a lot faster than you think. Heat in the voice coil is one of spl's worst enemys. Next to low battery voltage. So the last thing you want to do is play your system the day of the spl contest. find your tone @ least 3 hours in advance of going through the lanes. Most probes I have built have unusually low tones so you are not to far off. With 2 subs and 200 watts per you should be doing 137 db to 139db sealed or 140db to 143db ported if you cannot seem to get these #'s find a new installer. That should get you started!
------------------ Nothing beats EXPERIENCE!!!
Posts: 225 | From: cape girardeau, mo. usa | Registered: Aug 1999
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posted
Yes, due to impeadance curves so try and set your voltage @ your burp frequency. Chances are your freq. is higher than 40hz if you are tuned @ 38hz try some between 45 and 49 hz.
------------------ Nothing beats EXPERIENCE!!!
Posts: 225 | From: cape girardeau, mo. usa | Registered: Aug 1999
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posted
If I have a sweep generator and I send a slow sweep to the subs and I measure the speakers impendence while the sweep is running. Is it true that the most effecient (and loudest) freq will be the freq that is used when the speakers impendence is at its lowest?
(I gleened this somewhere and I could have it all worng)
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