Guys, I'm just curious about why my subwoofer (boxed 12" pioneer) pumps a lot harder when I open the boot ? Does this indicate the box might not be sealed up ? I have it sitting up loosely against the back seats (facing forward)... Its really a noticeable difference, you can even see the rearview mirror shake a lot more with the boot up. A mate of mine also had this trouble in an Apollo that he had, but I never took too much notice until now. Is it just normal or is there something I can do to fix it ?

if its a sealed box then ur boot is prolly either too small or you havent got anywhere for the pressure to escape, all subs require space to fluctuate in and out. Also, make sure that the box you have put the sub in is to spec, if its a sealed box that is too small or to big for the sub your running then you wont have enough back pressure behind the cone to push the cone out when the environment outside the box is to small and/or pressurized. try folding one of your back seats down to see if it makes a difference.

thats just my 2 cents... my sub sounds worse when the boot is up (if im sitting in my car) and thats how it should be

the bass should be louder inside the car when the boot is closed. is your sub facing towards the cabin or towards the tail lights? the bass is louder when facing towards the tail lights as i have tried all different positions and found that this was the best and a lot of other people have aswell. if your bass is louder when the boot is open, it means you have cancellation issues. check out http://www.caraudioaustralia.com for more info. someone will be able to help you.

-George

i found that keeping the sub facing the back of the car makes more bass inside the car,

btw....do u mean by....it sounds better when ur standing outside with the boot open...or when ur in the car and have at first boot closed and then compared with the boot open?

when i had the 12" in my car with an open boot it sounded weaker...closed the boot and it pumped...but when i was standing outside of course it sounded better open.

thank god for free air subs =D

I currently have the sub facing forward and when I say it sounds better with the boot open, I mean from within the car and it is louder, beatier, and more solid than in the same position (drivers seat) with the boot closed. The sub is a factory boxed pioneer so there are no concerns about the box size. I had the same sub in my previous Falcon and never noticed this so it must be something about the shape, size or sealing of the boot on the Fairlane... I'll see if turning it around changes anything but I'm not too hopeful...

Try reversing the phase on it.
Swap positive and negative to the sub.

yeh deinently sounds like something goin in with pressure....does your HU have the sub normal/inverted setting...try reversing that....boot open then shut test see if theres any diff....

Also does your sub box/enclosure have dakron in it ? .... if not should get some as it will trick your sub into beliveing and performing like its in a much larger enclosure.....sounds like your box is too small or too big...that or somethin else funny is goin on.

Mine loses most of the sub with boot open, punches quite well for a 10" when closed tho.

is it a dual voice coil sub, maybe you have wired it in series rather then paralell or just havent wired one coil up... seems weird to me still..

yeh i dunno if its dual id still think he has both coils wired....could be in series...youd think tho it shouldnt go better tho when the boot is opened...it should dim down more cause because more sound will be lost to the outside rather than the sound waves bouncing throughout the boot.....i'd confirm the phasing tho...see if you have it set to inverted by accident then your sub would use the boot space as its enclosure well sort of and fire the sound into the enclosure.....sometimes this can provide better results but not if the enclosure is too small.....hence maybe why when you are opening the boot...the sub syas hey ive got a bigger enclosure now i dunno....weird tho evry weird....let us know as many specs as u can...

Sub: Make/Model
Coil/Coils: single or dual
What impedance/ohms each coil is
how many watts RMS the sub is rated at and its peak value.
Cabling guage from sub to amp and from power source to sub amp
What make n model amp
How the sub is wired to the amp.....is it a mono....2/4 channel...is the sub connected via a bridged channel
If so whats the amp rated at Watts wise for that channel setup
If u can the enclosure size again....location in boot and what direction the sub is facing...
and just confirm the Head unit subwoofer settings are correct....
Do u have any bass booster/loud control on?
Have u set up any custom EQ settings ?

I apologise if any of the above question have already been stated in ya post

i remember when i wired my sub up once after having it out of the box it was really weak and it turned out that one of the wires had fallen out of the 2nd voice coil... this wouldnt really explain why it sounds better with the boot up though, phase shift COULD help but to be honest i dont notice any difference when i have my amp set to 180 phase shift or 0.... this seems to be one of those problems thats hard to figure out but i bet its right under your nose and so obvious.... :/

It's called cancellation. I've heard it happen in EVERY sedan with the sub facing forwards. Turn the box around so that it is facing the rear of the car and the problem will be gone.

http://www.installer.com/tech/aiming.html

no you havent. your completely full of s**t. i have seen many many cars at comps, my mates cars, other peoples cars etc with the sub facing forwards and it is NEVER louder inside the car with the boot open. Theres something else going on here that he hasnt covered.

same thing happened in my mates VN with 2 boxed 10s,
had no idea what was going wrong, the box was facing inwards, he just bought a boxed pioneer 306c and he dont have that problem anymore

weird