Custom VR setup questions...

[Pascawali]

Hey there, I have just started setting up my own audio system in my car and just hit a few kinks in my road to success.
First of all, my amp is a 2 channel 400rms jensen audio amp running a 1200w 12" pioneeer sub.
Now, my problem is...my headunit has a subwoofer preout (1 female) whereas RCA's are all 2 males so can I get a splitter to connect to this preout?
and secondly...my subwoofer doesnt put out AS MUCH as I hoped for...
I made my own custom box, it is completely enclosed and roughly to the dimensions stated by pioneer itself. On the other hand, a lot of people believe the box is too big for one sub...so not too sure.
Any advice and/or suggestions will be nice.
Thanks!

[benno9911]

for your rca i just went and bought a Y spliter from dick smith for like $4 dose the job fine as you can see by the pic below

[aazn]

or you can split it from the back of the headunit with a RCA spliter and run the pair down to the back... i find this to be neater install and if you do ever change your headunit, all wires are there for you.

[holdenboy]

Im taking it you have a Jensen head-unit? They are the most common around that have only 1 sub RCA output. If this is the case then yep a Y splitter like above is perfect, connect the Y splitter to the subwoofer output on the head-unit, then connect the normal RCAs to that and to the amp.

If you are only using one input on the amp then your only using one of the channels.....regardless of whether you have the output channels bridged or not. Get that Y splitter from Dick Smiths or a similar product from Jaycar:
RCA Plug to 2 x RCA Sockets Audio Lead - 300mm - Jaycar Electronics

Please post up some pics and / or the specs of the sub box.

[Pascawali]

Thanks heaps guys! I was thinking of getting a Y splitter, least now I know where to get them from.
Alright as for the sub box I think im using 18mm mdf or something similar... Measurements are as follows:
(These are outside measurements)
Width: 930mm
Height: 330mm
Depth: 340mm
and it has proper sound foam shit (whatever you call it) inside...
The sub is facing to the rear in the centre, with only a small hole in the rear of the box where the wiring comes out...
BTW Good guess...I am using a Jensen head unit, its actually a great product (kudos to Jensen)...has 2 separate RCA Preouts and a sub preout

[Pascawali]

There are some pictures

[RoboticCherry-Coke]

I just did a very quick calculation and that box is 3.68 cu.ft. (that is without me taking wood thickness or sub displacement into account). That box is way to large for a sealed enclosure. I have a pioneer sub and the maximum pioneer recommends for mine is ALOT less than that. Also any holes in the box are going to effect how it sounds. I would grab some sealant and plug up that hole if I was you.

[Pascawali]

Thanks man any input is useful!
I thought so too, I used to have it semi ported (a weird way) and it sounded terrible so I plugged it up and it sounded half decent.
Also, thanks for the calculations, I TRIED to work off the details (probably failed in the process). Except I thought, considering the fact the wood is fairly thick and it has sound material foam stuff inside it wouldnt matter too much?
If I was to port it, how big do you think the port should be? Ta.

[RoboticCherry-Coke]

Well you have done the right thing by building it out of 18mm MDF. Ported enclosures are always larger than sealed ones so you could probably turn yours into a ported box quite comfortably. I could probably make some suggestions as to the port size and length but I would recommend having a word to someone who has more experience building ported enclosures than me. I have been spending a far bit of time lately speaking to holdenboy and acarmody regarding ported boxes as I am currently in the planning stage of building a new one.

Check out this thread out, it is the that I have been getting advice from holdenboy and acarmody in. You may find some of the info helpful.

[Pascawali]

Thank you so much Cherry! I really appreciate the help, I just hope I can get it going alright.
Also, If i were to resize the box, I would probably just make it less wider...and just keep the front as it is...so it sits flush in the back yet the box size is rather smaller. I will see what I can do, fingers crossed I can port it ok...
Hopefully holdenboy replies on this post

[RoboticCherry-Coke]

Thats ok man, happy to help

I just had another look at your box size. The capacity of your box is 2.745 cu.ft. Thats taking into consideration sub displacement and the MDF thickness. Now I am not that sure about your sub but the maximum pioneer recommend for a sealed box for my sub is 1.75cu.ft. If I was you I wouldn't worry about changing the boxes dimensions, I would just add a port but then again I am a bit of a ported box fanboy

Anyway I will keep an eye on this thread and if you don't end up getting any help with port size and length I will try help out best I can but I would rather leave it to one of the other guys with more experience so you can get the best results

[MiggzvsC0MM0D0RE]

Hey man, if you do want to re do it you can use the Rockford Fosgate® - Woofer BoxWizard This thing is absolutely fantastic.

[Pascawali]

Thanks mate I had a look at it and I think it will come in to be brilliant help!
Thanks cherry for the help, feeling much more confident now just gonna wait till I get some dosh and then I will figure things out!
Oh and update...I bought a RCA splitter today so this weekend I will put that in and see how that goes

[dumpedvs]

Speaker Enclosure Volume Calculator

Use that website to help you out if you want, got some good info.