just spent the last few days installing 2 12" vr subs in the boot and running all the cables to the alpine mrv 501 amps yet the subs don't seem to be working as good as in my previuos car, i've always had a sealed box that faces forward (sounds better) yet i'm seeing a lot of people face them towards the rear, are the boxes ported so the sound is pumped into the cab at all otherwise you wouldn't get get a real solid "doof". in the last car (explorer 4wd station wagon) you could really feel the base but so far i'm not getting that. would porting the box help????

From what I've been told, ported boxes are louder than sealed, however sealed boxes allow for punchier bass.
Sealed need more power to make noise because they have to work against the sealed air in the box that sucks the sub back in.

I used to face my sub toward the cabin, but I've found in my magna that its louder facing out.

yes, ported boxes are more efficient. in general, they play louder and lower(sometimes)...depends on what frequence you want it 'tuned' at. I found facing my 2 12s in 1.1cu ft sealed box back or front made no difference at all, hahaha.

Porting it would help a lot. Facing it backwards...well, thats just a 5minute job :)

Do not modify your existing box by adding ports to it! A ported box will always be larger then the sealed box (Thats the trade off, most people use sealed enclosures because they need room for other things). The size of the box and the length and diameter of the ports (they are tuned) need to be calculated for optimum results

both are good it all depends on what music you listen to.

if you listen to a fair amount of rock, rnb/rap that sort of music with deep bass notes then ported is much better and does it justice. also it has to be ported to a decent freqenecy. say if its ported to 60hz, and you set your low pass crossover point on your amp at 80hz, the sub will play solid bass from 80-60hz, anything below 60hz looses its depth. and thing is you cant really hear distortion with a ported box.


sealed boxes are smaller and good all round if you listen to a variety of music, and has a crisper cleaner punchier bass suited to say electronic music and most pop/alternative music.


if you want deep "boomy" bass which can be heard outside your car from a block away then vented.

if you want clean accurate bass sealed.

ive had both and i must admit i liked vented because it was slightly louder, but after a while it i considered it "messy" and went sealed. depends on music type and personal pref. have a listen to ur mates systems if they have such boxes.

Sounds like you have phasing problems. You may have altered your wiring, and the acoustics of the car itself would be very different.

A speaker is out of phase with another speaker when one is pushing in, while the other is pushing out. Easy way to fix this that won't damage your equipment) is to swap positive and negative wires on the sub)

Few things to try (may sound silly, but they're quick)

Try turning off your rear speakers, just fade them to 0. Do this through a punchy bass song that you're familiar with. Pay careful attention to the timing of the bass notes to your ear.
You may now notice that the notes are not as muddy, and all hit you at once.

Also do the same testing for the fronts.

If you see a noticeable impact your speakers are out of phase with your subs and each other.

Also a high chance your subs are out of phase with each other. This will definetly cause cancellation. Unplug one. See if the notes arent as muddy. Change the polarity of one sub, (negative to positive. positive to negative)
Notice any difference.

Porting vs sealed is not your problem imo.

If you dont notice anything from all of this. Play some music, and whilst you're in the car, open the boot, lemme know if this improves the notes.

Once again, may sound stupid, but you have waves reflecting around your car, and if these are out of phase, they will cancel each other out.

Speakers being out of phase isnt always a bad thing, by running them like this many people after sq, can disguise the subs which causes all the bass to appear from the front of the car.

Let us know how you go.

Peace

Tim

it does sound louder once the boot is open but i won't be driving around with the boot open :confused: I have phased the subs which certainly makes a big difference perhaps on my days off i'll try the speakers see how it goes, i might try see if i can channel all the sound through the seat hatch a bit better. in my old falcon i had 60 / 40 splits and when you folded the rear seats down the two subs were right there firing away beautifully :dancin: :) . that's what i'm trying to achieve again but so far :(

it does sound louder once the boot is open but i won't be driving around with the boot open :confused: I have phased the subs which certainly makes a big difference perhaps on my days off i'll try the speakers see how it goes, i might try see if i can channel all the sound through the seat hatch a bit better. in my old falcon i had 60 / 40 splits and when you folded the rear seats down the two subs were right there firing away beautifully :dancin: :) . that's what i'm trying to achieve again but so far :(
K if it sounds louder with your boot open, then you have cancellation. Prob not due to wiring.

Easy fix, face your subs backwards, you do not need to fire through the ski port to get good bass, bass will pass through the seat easily as the waves are larger (lower frequency).

If you face them backwards they will reflect off the boot and the waves will be in phase with each other as they point in one direction. With them facing through the ski-port; (if the sub is not sealed off from the boot) You will get waves going through the hole into the cabin, and also waves reflecting around the boot, eventually hitting the back of the boot and then going forward. As these waves are not 'in phase' with the waves already going through the ski port, they will cancel each other out.
This is why it's louder with your boot open, there is no cancellation.

Try facing them backwards in the cabin (preferably as close to the rear of the car as possible, this will solve most of ur issues.

Peace

Tim

aahha i see i will give it ago on tues (first day off). in my last car i had (ford explorer :rocket: ) i tried facing them backwards but they sounded really "poppy" and so i faced them forward and they sounded great but i guess different accoustics are at play here. hey is it a big job to change the front splits and is there a crossover somewhere for them?

Hmm, the stock splits?

I havent uninstalled any stock Tj splits b4. Im sure ther would be a crossover somewhere, couldnt say where though. Might be internal.

Fairly easy to install front speakers.

Do a search, it's been done to death.

As for splits, you'll just have to run the wiring yourself. Hardest part is getting new wiring through the door grommets. You can use the original wiring if you're not too fussed. Then put your new crossover in the door, and mount your new tweets in a custom spot on the door, or into the delta mount. (check if they'll fit first). The wires just run into the door.
Or if you want to run them off amps just run the wiring down the cable tracks along the side of the car.

bugger it just playing around and mutilated my sub box :badgrin: , chopped it in half and will use my old zr sub only cause two vr's sound **** house where as the zr through the ski hatch has a great punch to it... now onto the dd driver front splits :D