simple questions. Don't Laugh, I'm an SQ guy.
06-13-2004, 10:05 PM
#1
1.I was wondering if anyone happened to know the resonant frequncy of a 1994 Dodge Caravan.
2. the port volume required to best match the res freq of the van in a 4.5Cuft box that will house a single 12" Kicker Comp VR.
3. Would I be dreaming if I thought I could hit 140 or better with that set-up using a Rockford 301S loaded down to 2 ohms?
Don't laugh at those questions, I'm serious, I wanna do a couple SPL events before next year when I start building my Cavalier for SQ. Actually it's just an excuse to go to more shows.
2. the port volume required to best match the res freq of the van in a 4.5Cuft box that will house a single 12" Kicker Comp VR.
3. Would I be dreaming if I thought I could hit 140 or better with that set-up using a Rockford 301S loaded down to 2 ohms?
Don't laugh at those questions, I'm serious, I wanna do a couple SPL events before next year when I start building my Cavalier for SQ. Actually it's just an excuse to go to more shows.
06-14-2004, 01:43 PM
#2
500 Watt CAFz'r
Join Date: Sep 2002
Posts: 610
Those are very valid questions Brandon...
First off, the resonant frequency of each vehicle is different, even in the same model of vehicle. Much is dependant on how the vehicle was put together, what level of trim it has, what features and each one built does not have the same amount of sound dampening material, nor is it normally placed in the exact same spot. Your best bet to find the resonant frequency of your vehicle is to hook up a 10 inch sub in a sealed enclosure to your system in the vehicle, run pink noise through your system and measure it on an RTA. That'll get you almost dead on with what frequency your van resonates at...
Once you know your resonant frequency, plug all the sub info into TermLab and tune it to that frequency. That'll tell you what port volume you'll need.
If you have the enclosure tuned to the resonant frequency of the van, I don't see why you couldn't attain a score of 140 dB. There was a girl at the Oshawa show this weekend with a single MMATTS 12 running on a Phoenix Gold Tantrum T250.2 (250 watts) hitting 141.3 on the new AudioControl sensor, so I don't see why you couldn't do it with your equipment. I'm not overly familiar with the Rockford equipment, but I would think it has at least 250 watts!
Hope this helps!
First off, the resonant frequency of each vehicle is different, even in the same model of vehicle. Much is dependant on how the vehicle was put together, what level of trim it has, what features and each one built does not have the same amount of sound dampening material, nor is it normally placed in the exact same spot. Your best bet to find the resonant frequency of your vehicle is to hook up a 10 inch sub in a sealed enclosure to your system in the vehicle, run pink noise through your system and measure it on an RTA. That'll get you almost dead on with what frequency your van resonates at...
Once you know your resonant frequency, plug all the sub info into TermLab and tune it to that frequency. That'll tell you what port volume you'll need.
If you have the enclosure tuned to the resonant frequency of the van, I don't see why you couldn't attain a score of 140 dB. There was a girl at the Oshawa show this weekend with a single MMATTS 12 running on a Phoenix Gold Tantrum T250.2 (250 watts) hitting 141.3 on the new AudioControl sensor, so I don't see why you couldn't do it with your equipment. I'm not overly familiar with the Rockford equipment, but I would think it has at least 250 watts!
Hope this helps!
06-14-2004, 11:35 PM
#3
LOL, thanks Moe, yea it helps.
Yea the Rockford should make around 6-700WRMS at 2ohms, which it's not really supposed to be run at but because I'm me, I'm gonna do it anyway.
Which girl was this running the PG tantrum amp?
I didn't spend a whole bunch of time over at the SPL are but I did hear some BIG noise comming from over there.
Where can I get TermLab?
Yea the Rockford should make around 6-700WRMS at 2ohms, which it's not really supposed to be run at but because I'm me, I'm gonna do it anyway.
Which girl was this running the PG tantrum amp?
I didn't spend a whole bunch of time over at the SPL are but I did hear some BIG noise comming from over there.
Where can I get TermLab?
06-15-2004, 12:02 AM
#4
Guest
Posts: n/a
What Moe said about finding resonant frequency is very good, but he missed one important step. You must also measure the response of the sub and enclosure in a free field environment and subtract it's response from the in car response. This will make sure you are focusing on the cars resonant frequency and not the subwoofer systems resonant frequency.
06-15-2004, 07:25 AM
#5
Guest
Posts: n/a
140 should be a breeze, at our show on the weekend we hit 150.6, with 1 15" phoenix gold titanium 15, in 5 cubic feet ported, running off a phoenix x1200.1, we built this car in a night, no testing for resonant frequency or anything, it was measured on the ac mic
06-15-2004, 07:39 PM
#6
Originally posted by DWVW:
What Moe said about finding resonant frequency is very good, but he missed one important step. You must also measure the response of the sub and enclosure in a free field environment and subtract it's response from the in car response. This will make sure you are focusing on the cars resonant frequency and not the subwoofer systems resonant frequency.
What Moe said about finding resonant frequency is very good, but he missed one important step. You must also measure the response of the sub and enclosure in a free field environment and subtract it's response from the in car response. This will make sure you are focusing on the cars resonant frequency and not the subwoofer systems resonant frequency.
06-15-2004, 07:42 PM
#7
Originally posted by defro13:
140 should be a breeze, at our show on the weekend we hit 150.6, with 1 15" phoenix gold titanium 15, in 5 cubic feet ported, running off a phoenix x1200.1, we built this car in a night, no testing for resonant frequency or anything, it was measured on the ac mic
140 should be a breeze, at our show on the weekend we hit 150.6, with 1 15" phoenix gold titanium 15, in 5 cubic feet ported, running off a phoenix x1200.1, we built this car in a night, no testing for resonant frequency or anything, it was measured on the ac mic
06-15-2004, 09:08 PM
#8
Guest
Posts: n/a
Originally posted by Brandon:
</font><blockquote>quote:</font><hr />Originally posted by DWVW:
What Moe said about finding resonant frequency is very good, but he missed one important step. You must also measure the response of the sub and enclosure in a free field environment and subtract it's response from the in car response. This will make sure you are focusing on the cars resonant frequency and not the subwoofer systems resonant frequency.
</font><blockquote>quote:</font><hr />Originally posted by DWVW:
What Moe said about finding resonant frequency is very good, but he missed one important step. You must also measure the response of the sub and enclosure in a free field environment and subtract it's response from the in car response. This will make sure you are focusing on the cars resonant frequency and not the subwoofer systems resonant frequency.
