posted
I was beginning to think of ideas for a competition vehicle for next year. I wondered if bandpass would be the best option. I am considering a vehicle that is very long, but not very tall or wide. I was thinking that if I walled it off, it would barely be big enough to put much in there (without doing a wedge, which causes cancelation). I was thinking of a bandpass enclosure with only the ports being on the wall, with the subs facing the sides of the car in the back. Does this work for SPL? Has anyone seen another vehicle like this?
------------------ Shedluv No matter what it says, I'll always be just a junior.
"Eagles may soar, but weasels don't get sucked into jet engines."
posted
Bandpasses also create cancellation. If you build a square box, there is cancellation in that too. The only way to avoid any type of cancellation is to build the box with different angles on it. Polyfill also helps a little. But as for SPL out of a bandpass, from my experience, it will sound loud, but it won't show on the meter. I don't really know why that is. But that has been my findings with bandpass boxes.
------------------ Hittin' hard wherever you are......
Posts: 2542 | From: Moberly, MO USA | Registered: Jun 1999
|
posted
I totally agree. My first setup in my car was 4 12's in a bandpass box... Boy did that thing play low and hard... but when it came to get it metered, I was very disappointed.
posted
I am not a huge fan of bandpasses, especially for SPL, but if you really knew what you were doing, you might get away with some decent scores. I'll share the info on my friends system (which is really the only big BP system I have seen compete in any SPL events around here). He has: 2 Stinger SBP-1000 batts, 1 for the car and 1 for the system, 2 1f Stinger caps and all the appropriate gauge wiring, a high model Kenwood Deck with about 4 V pre-outs, A Soundstream SVX4 x-over, 2 SS 10.0 amps, 8 SS SPL12's in a Bandpass wall in the extra cab of his S10 with 2 big ports. His scores were 154 and some change in outlaw and right at 150 legal. His system wasn't pure SPL, as it had a decent pass band and sounded OK with music, and his note was around 30 hz, but the box was tuned around 60. The things that would have given him a higher score would be 1. More power-with 2000 watts the subs were still underpowered they needed about twice that, 2. Dump the caps and use more batteries-that has been proven to help SPL by some on this forum and others, and those current hungry 10.0's would like that better 3. Do some cab mods-You would't believe the amount of body flex this truck had, even behind the wall at the rear cab! Anyway, that is what he could still do (without changing the box itself) to improve the scores he already has. That 150 is a decent score but it was on an Audio Control meter, so he would probably lose a little on Term Pro or Linear X. Anyway, I'm saying a BP system could do OK in db Drags, it would probably be easier to do it with a more conventional ported or sealed box, and I am a firm believer that BP systems tend to reach their limits faster than the others. But if I was going to do a BP for SPL, I would 1. Use lots of power, 2. Do some testing to find your resonant frequency and tune the box close to it with a narrow passband, giving a higher peak around the tuning frequency. 3. Do some cab reinforcing if possible.. That's just my opinion, I'm sure someone else will have some advice
posted
I have just built a bandpass box for 2 SS SPL160's. It is just a project but I figured no guts no glory so I went for it. The car has a fully modified interior and all you can see is the ports for the boxes. It looks bad ass and I will get back to this post when I get the car metered. I'm not expecting too much but hey, maybe I'll get lucky. Who knows until you try?
------------------ Adam Sippel AMA 3-4???? TEAM EPICENTER "Step up to the button!!" 1999 USAC Wisconsin State Record Holder Outlaw AND Outlaw Extreme 101-250
Posts: 54 | From: Plymouth, WI, USA | Registered: May 1999
|
posted
I HAVE 3 X 12 BANDPASSED IN A GOLG AND GET 150 PLUS ON A AUDIO CONTROL. IF YOU GET THE FREQUENCY RIGHT THE BOX CAN WORK, I SWITCHED FROM PORTED TO BANDPASSED FRONT PORTED REAR SEALED, WENT UP BY 2 DB AND MORE PROTECTION FOR THE SUBS
------------------
Posts: 16 | From: south africa | Registered: Jun 1999
|
posted
The bandpass gave me 2 more db legal. not bad for 2 subs compared to 4. Not enough though, will be redoing the boxes and dding some more power.
------------------ Adam Sippel AMA 3-4???? TEAM EPICENTER "Step up to the button!!" 1999 USAC Wisconsin State Record Holder Outlaw AND Outlaw Extreme 101-250
Posts: 54 | From: Plymouth, WI, USA | Registered: May 1999
|
posted
I am thinking of a vehicle that is like a limo (but not a limo, or hurse), that has very little height or width, but tons of depth. Could I mount the subs facing towards each other facing the center of the car and just leave a long tunnel for the bass? I thought that a bandpass would be better than that. I can only fit about 4 or 5 woofers in a traditional wall, but probably 10-15 in a bandpass or tunnel.
------------------ Shedluv No matter what it says, I'll always be just a junior.
"Eagles may soar, but weasels don't get sucked into jet engines."
Printer-friendly view of this topic