I've finished building the basic box for now (just a 16mm MDF rectangle box with divider) and am still trying to figure a few things out... just wondering if anyone can shed some light on these things...

1) Is there any better way to seal a box? i've screwed, glued, and sealed the inside perfectly, but i was thinking something along the lines of fibreglass resin/varnish to seal the box completely and make it water-proof aswell? anyone know if this would work and have any decent benefits?

2) The subs are capable of taking a speaker wire up to 8ga, but good luck finding a speaker cable that thick... i was thinking of doubling up some 12ga speaker wire... if this would help at all?? i will be running 500WRMS into each sub, so i was as minimal loss as possible, i'd also need terminals that could take a larger wire aswell...

3) I know its been asked before, but do subs actually sound good facing forwards in a magna? i'm running 2x Pioneer TS-W1201C subs (500WRMS each) off a Alpine MRV-1001 (1000WRMS amp @ 2ohm, both subs are 4ohm, making 500WRMS each at 2ohm i figure?) at the moment they are facing backwards, and can sound a little delayed on some complicated tracks, but the volume is awesome... would there be much difference if i turned them around?

I have 2 12" alpine type "R" subs in my magna facing towards the back and your rite there is a bit of a delay on sum sort of tracks but the output is higher. I tried them facing forward and they sounded ok but not as loud. (due to no rear sound loading)

As for 8g speaker wire, i use stinger 8g power wire on mine and i sealed the inside of my sub box with fibreglass resin.

Your box should already be sealed after that much work. One benefit from glassing the inside is to stop flex of the mdf. If you are aiming to get higher db's you would be better off inserting small strips in the corners at 45 degree angles as this will also increase db's. Then think about glassing the inside. I dont think ul have any problems with it though.

You can get 8 gauge speaker wire, try jaycar and car audio places. For best results avoid using any terminals and run the cables right through the box if u can. Otherwise ensure good connections (solders and heatshrunk) to ur terminals)

My subs are facing forwards and sound great. But if you face them forward you NEED to seal off the boot as much as possible using a mini wall. Otherwise you will get reflections from the rear wave bouncing off the boot and cancelling out with ur front wave.
If you have enough power and cone area ul b fine. If you only had 1 12" or 1 10" with lower power handling I wouldnt recommend it. Especially if your subs dont have as much low end extension. By rear loading you get that extra bit of depth down low from cabin gain. If your subs already play that low on their own... (Cough DD's) You wont have a problem.

If you seal off the boot with a mini wall u will get fewer boot rattles too. But with as much power as you have you will need to deaden ur boot.
I started this a couple of weekends ago and did a bit more this weekend. Decided to use the paint on deadener in between the struts on the boot lid and then astromat everywhere else.

Not finished yet but now the rattles have moved to the underside.

Peace

Tim

I've finished building the basic box for now (just a 16mm MDF rectangle box with divider) and am still trying to figure a few things out... just wondering if anyone can shed some light on these things...

1) Is there any better way to seal a box? i've screwed, glued, and sealed the inside perfectly, but i was thinking something along the lines of fibreglass resin/varnish to seal the box completely and make it water-proof aswell? anyone know if this would work and have any decent benefits?

2) The subs are capable of taking a speaker wire up to 8ga, but good luck finding a speaker cable that thick... i was thinking of doubling up some 12ga speaker wire... if this would help at all?? i will be running 500WRMS into each sub, so i was as minimal loss as possible, i'd also need terminals that could take a larger wire aswell...

3) I know its been asked before, but do subs actually sound good facing forwards in a magna? i'm running 2x Pioneer TS-W1201C subs (500WRMS each) off a Alpine MRV-1001 (1000WRMS amp @ 2ohm, both subs are 4ohm, making 500WRMS each at 2ohm i figure?) at the moment they are facing backwards, and can sound a little delayed on some complicated tracks, but the volume is awesome... would there be much difference if i turned them around?

Most people, screw and glue their boxes together, and i think that is pretty well sealed already. However, fibreglass helps the box become...virtually waterproof! lol I think u should brace up the insides of your box, and glass the boobies out of it, definately no air leakage!

As for speaker wire...well, you don't need up to 8 gauge wire, and I doubt resistance in a 12 gauge wire would make that much of a difference at all. 12 gauge wire is all you need.

For terminals do you mean those blingy looking terminals you can get from jaycar that screw into the back of the box? I've never used one, but apparently those things leak air, so probably not a good thing for u to do. I usually drill a hole (small enough for speaker wire to get through)...but since you want to be extra careful, i say just pump the hole up with silicon, or even fibreglass.

Front loading, rear loading...corner loading..well, I guess you'll have to do it to find out! i think timeh found out front loading didn't give as good low end respose, so i guess you want to face yours..backwards

I just doubled some 16ga stinger wire to make it = to a 10ga wire.

Rear load for sure.. have you tryed putting your subs out of phase while rear loaded, you lose some volume but keep the low end extension that you get from rear loading. :D

thanks for the prompt replies guys! i guess i should have mentioned, i'm not going for all-out dB, more "as-loud-SQ-as-possible" kinda thing...

heres some specs on the subs, as i'm sure if makes much more sense to some of you guys than it does to me!

http://www.pioneer-eur.com/images/products/carspeakers/pioneer/1012233151321ts-w1201dvc_detailpage.jpg


Frequency response - 15 - 2.000 Hz
Sensitivity - (1W/1m) 88 dB
Qts - 0,29
Recommended sealed enclosure (Litres) - 28,3
Lowest resonance frequency (FS) - 20 Hz
Maximum Power - 1.000 Watt (500 RMS)
Vas - 118 l
Woofer size (cm) - 30 cm

the amp is one of the most tuneable ones (that i've seen) but again, i don't really know what much of it does! i'm used to the simple gain and LPF control!

http://www.boostcaraudio.com/photos/Alpine%20MRD-M1001-2.jpg

here's the amp specs also:


1000 watts RMS x 1 at 2 ohms
2-ohm stable
variable low-pass digital crossover, 30-200 Hz, with selectable 12 or 24 dB/octave slope
variable subsonic filter (15-50 Hz in 5 Hz steps)
parametric EQ variable from 30-160 Hz, ±12 dB
Bass Compensator circuit enhances low-end definition (3 settings)
time correction 0-10 milliseconds in 0.1ms steps
phase adjustment 0-180°
turn-on delay
preamp inputs and outputs
onboard fuse holder with four 20-amp fuses

Is the phase adjustable from 0-180deg? If it is try it between 85 and 100deg somewhere, I only have the option of in or out of phase. :doubt: You should also try the time correction, I think 3-5ms is good for a decent size car, Tim or Marty will know more.

Yes I was looking at those subs, they sound quite good but the amp will do most of the work. You might need to fiberglass as 16mm is a bit thin for those subs. :D

****!!
I just lost my post! Friggin mouse with clicky things on the side!!

Anyway, go 4 guage, the amp will be better off with it.
For the box, i'd make grooves, male joiners with female revievers - so they slot together. Throw in some glue with some small nails with a carpeted box and she'll be bangin. Just find out what volume the sub needs for optimum performance.

EVERYONE!
Face the sub towards the seats, and pull the middle seat down. You increase the bass so much. You dont hear it out the rear of the car so much, but its so much more better hearing it forward.
You want people to hear you in advance not when your halfway down the street.

thanks for the ideas guys, i reckon i'll give the forward facing subs a shot, while building a wall behind the sub box to seal the boot off completely, and also will make mounting the amps much neater. (i'm pretty sure i've got enough spare MDF to give it a go)

i reckon i'll have the subs on the outer edges of the box, with the 2 capacitors mounted between them (so u can see em with the seat folded down) with the amps on the other side of the box, (power cable from caps to amps should be only .5m long, maybe a tad more)

i'll eventually be replacing the 6x9's with some focal 5" coaxials to match the front, these will hopefully be sealed seperately from the subs aswell to avoid any cancellation... hopefully this will all go to plan :D

****!!
I just lost my post! Friggin mouse with clicky things on the side!!

Anyway, go 4 guage, the amp will be better off with it.
For the box, i'd make grooves, male joiners with female revievers - so they slot together. Throw in some glue with some small nails with a carpeted box and she'll be bangin. Just find out what volume the sub needs for optimum performance.

EVERYONE!
Face the sub towards the seats, and pull the middle seat down. You increase the bass so much. You dont hear it out the rear of the car so much, but its so much more better hearing it forward.
You want people to hear you in advance not when your halfway down the street.

but would you rather better sound in the car, or would you rather be a show pony and show off to all the other bogans with their rattling boot down the street. Anyone can make loud bass but getting those sweet sounding beats where you just go :D takes more effort.
I know id rather have the good sound to myself than share it with some street bogans

cheers
jaz

well, i just tried firing them forwards, and DAMN! for SQ reasons, it will definately be firing forward, i tried a couple of tracks from Nine Inch Nails, Faithless, Rise Against and Black Eyed Peas... and i couldn't find any faults at all... they definately sounded more in time and faster responding than before.

i remember i tried them firing forwards once before, and it sounded extremely crap... but that was with the old amp, this one seems to be working wonders :D very happy.

also means i can sit the subs closer together, and mount the capacitors in the back of the boot with the amps......

although......

would it make much difference if the subs are further apart/closer together? eg, firing straight thru the ski-hole, or bouncing off the back seat a tad? coz i reckon being able to see the capacitor voltage level inside the car is pretty cool :)

but would you rather better sound in the car, or would you rather be a show pony and show off to all the other bogans with their rattling boot down the street. Anyone can make loud bass but getting those sweet sounding beats where you just go :D takes more effort.
I know id rather have the good sound to myself than share it with some street bogans

cheers
jaz


Yes, I agree. You hear it more in the car with it facing forward with the seat down. That sweet sound gets even sweeter. You gotta admit it puts a grin on your face when people turn their heads to see your car though. Not all the time, but sometimes a bit of show is a good thing :)

yeah i gotta agree, even with that short listen i was quite surprised to see how well they performed facing the cabin, especially after all the hype of everyone saying "face em backwards!! its always louder!" but i guess that is more so in a hatch than a family sedan... while the deep low bass is probably still louder facing backwards, the rest of the kick and tight punchy bass is so much clearer its definately worth it

also, with the setup i had with them facing backwards, the entire ski hole was closed over with the sub box and amps, so i guess that could also have had something to do with it sounding crappy.

yeah i gotta agree, even with that short listen i was quite surprised to see how well they performed facing the cabin, especially after all the hype of everyone saying "face em backwards!! its always louder!" but i guess that is more so in a hatch than a family sedan... while the deep low bass is probably still louder facing backwards, the rest of the kick and tight punchy bass is so much clearer its definately worth it

also, with the setup i had with them facing backwards, the entire ski hole was closed over with the sub box and amps, so i guess that could also have had something to do with it sounding crappy.

If i ever get down to a adelaide meet, i'll let ya listen to my set-up

If i ever get down to a adelaide meet, i'll let ya listen to my set-up
cool! what do u have? (have to say, i haven't really noticed you around before) where ya from mate?


ohyeah, does anyone know if it would make a huge difference having the subs as close to the ski hole as possible, or off to the sides? (not sure if you'd be able to see the subs even with the ski hole open)

cool! what do u have? (have to say, i haven't really noticed you around before) where ya from mate?


ohyeah, does anyone know if it would make a huge difference having the subs as close to the ski hole as possible, or off to the sides? (not sure if you'd be able to see the subs even with the ski hole open)

My system consists of Infinity splits in the front, Alpine type "R" 6x9 in the back, 2 2channel T707 alpine amps (1 for the fronts and 1 for the rears) 2 Alpine 12" type "R" dvc subs powered by 2 Alpine MRD300 amp ( 1 per sub), Alpine flagship flipface head unit.

I live in the country now. Used to work at mitsubishi, was there for 10yrs.

I prefer the sound with the ski hole shut... All the music you want to hear from the sub should pass through the back seats easily. All the crap you hear from the subs directly (Cone noise, port noise, motor noise, surround noise, resonance, rattles etc) are all unwanted.

You got enough power to make ears bleed so unless ur after records chances are you already have enough power to 'overpower' the frontstage.

Peace

Tim

today i bought some link bars for my capacitors and some nice 4ga power cable :D so the whole power setup should be a lot neater than last time and hopefully a bit more power available aswell. will still replace the rest of the wiring from the battery with 2ga as soon as possible.


but....... (of course)


the screws supplied with the link bars are the wrong thread :confused:

one of my caps has the longer threads required, but the other is just the standard shorter ones so i'll have to get in contact with fusion to see whats happening there!


well at least on the weekend i'll be able to start planning where everything will go and mount the terminals, cut holes for woofers, line up where the amps will mount etc etc :D YAY :D

I rear load my subs as I like more Boom and Volume... I do fold down the ski port and the Bass is awe inspiring with as little as 50W RMS..
I prefer to rear load my subs as Audible cone noise is not desirable at high volumes..
If I face mine forward and fire them through the ski port I hear the " Someone beating a Cardboard Box with a Wooden spoon " noise.. Turn the sub around and it is gone, So I get a higher quality of Bass from rear loading and OK, there is a slight delay but nothing that ruins the music I listen to.

I cannot wait to be able to make it to a meet so I can hear what other AMC members have achieved..
125.3 dB SPL is enough for me from my single 12 inch

I rear load my subs as I like more Boom and Volume... I do fold down the ski port and the Bass is awe inspiring with as little as 50W RMS..
I prefer to rear load my subs as Audible cone noise is not desirable at high volumes..
If I face mine forward and fire them through the ski port I hear the " Someone beating a Cardboard Box with a Wooden spoon " noise.. Turn the sub around and it is gone, So I get a higher quality of Bass from rear loading and OK, there is a slight delay but nothing that ruins the music I listen to.

I cannot wait to be able to make it to a meet so I can hear what other AMC members have achieved..
125.3 dB SPL is enough for me from my single 12 inch

yeh not too bad i got 135 with 2 12"s off an 140W amp in my old 1st Gen Magna

My Competition setup got me 142.2db SPL, and that was at a Test at JB Hifi when they first opened up in Phillip ACT, and was with Two 12 inch Magnat XTC 1200 long throw subs in a custom ported enclosure with a Sine sweep of 45hz..