posted
what's the difference between tuning a regular trunk box and tuning a wall? someone said something about resonant frequency of the cab of the car with a wall? probably didn't spell it right, but hopefully someone knows what i'm talking about..if it's possible..does anyone know what the frequency is in a 92 thunderbird? and how this plays into the tuning that i'll have to do? i usually use winISD to tune my boxes i build..can i still use this for a wall somehow? please fill me in here people
-------------------- Posts: 299 | From: canaan, maine USA | Registered: Jun 2000
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posted
I'm intrested in this too... I have no idea how people would go about tuning a wall!
-------------------- (1) PPI AMP PCX-2200 (800 Watts @4ohms Bridged) PCX-480 for my highs (2) DD 3512a's in a 4.4cube box with 50sq. inches of port tuned to 33Hz Street 1-2 [TEAM DD] 147.7dB My Sound Domain page Posts: 1655 | From: Tucson, AZ | Registered: Jul 2001
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the thing you must keep in mind is that with a wall the distance from the subs to the dash is smaller, hence a smaller cabin volume, which means that the resonant frequency of the vehicle will be higher than usual. how much higher is hard to say...but i will say with my wall tuned to 43Hz i'm peaking at 58Hz outlaw and 56-57Hz legal...about 14Hz higher than tuning.
when my install was in the trunk i was peaking near 45Hz...now with a wall it's much closer to 60Hz. but this will vary with vehicle.
just tune the wall the same way you would a trunk install...it's the same formula. all it is is a box with trim panels you can use WinISD to tune your wall...i find it to be pretty accurate but nothing works better than trial and error hehe.
if you want, post your box size (and port area too. also if it's gonna use one wall of the box as a port wall as well...that makes a big difference) and subs here (with a link to T/S specs if possible) and i'll run it thru bassbox lite (my xmas present) and see what it says for port length.
-------------------- To cheat is to admit defeat
--------------------------------- Loud...it's when you can see the ground move, it's when you have to force yourself to breath, it's when the rest of the world ceases to exist.
posted
thank you soo much, it's going to be 4 shocker 2 15's using probably 2 sides of the box..the volume will be 5 cubes each chamber (gonna be 4 chambers) and obviously 4 seperate ports. the port area is gonna be 66 sq inches, probably wanna get an idea of tuning to 40 and or whatever you'd recommend, thanks
chad
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Posts: 299 | From: canaan, maine USA | Registered: Jun 2000
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posted
If you want it accurate, you'll need to map the transfer function and see where the peaks and dips are below 100hz or so.
With a wall, you'll more than likely have to build it first and tune it afterwards. We had to.
This is the difference between tuning walls and trunk boxes. Walls effectively displace a significant amount of cabin volume and alter characteristics.
With 20 cubes, and 40 hz tuning your 66sq in will need to be 14.5 inches deep. Assuming thats 66 per sub.
posted
sometimes the port can be tuned higher, i.e. to 60-70hz yet you peak at 55hz.
I've seen this in many SS1-2 cars, if you punched all the numbers in the computer program it would come up with peak freq at 60+hz, but because of the cars res freq being lower the peak is around there.
but its usually much higher then street installs, i.e. i went from a (street1-2)47hz tuning to a (superstreet1-2)53hz.
some people just build a big a$$ box and stick the front of the box on and keep on changing the front to change the port area. Best way probably.
jaggy
-------------------- Digital Designs...true to the source
Posts: 1959 | From: England, UK | Registered: Dec 2000
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posted
ok, after looking at his car, i think i'm gonna make ONE chamber instead of the original 4, and one port for daily and a different port for comps the daily port tuned to 35 and the comp port tuned to 45... each port needs to be 264 sq inches of port area. and instead of 5 cubes per sub it's going to be 4...soooo altogether it's going to be 16 cube shared chamber box..if anyone can help with this, it would be GREATLY APPRECIATED thank you everyone for your help, it means a lot to me to get help like this..
chad
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Posts: 299 | From: canaan, maine USA | Registered: Jun 2000
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posted
hey conctact bassntbird on this forum he hasnt ben on in a couple days but i can tell you we put a wall of 4 12" shockers separate chambers , then switched to 4 kicker squares 12"s and had great results as well. email him at drewtb215@netscape.net he will help you by the way his tbird is a 93 so should be the same and all testing was done on my termpro so i would say its pretty accurate hope this helps ya- jeff
-------------------- RETIRED Competiter CAR TUNES KUSTOMES Team Lanzar Team DD Authorized DD dealer in NY Posts: 1314 | From: wayland,ny 14572 United States of America | Registered: Mar 2000
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