engin_ear

iTrader: (1)

I've read Sparky3's (Shawn) post on 12" subs in a GS - from a while back - but I still would like to hear from those who have rear-firing woofers, esp. dual 12's. Is this an acceptable method for SQ? Cause I'd sure as hell like to do it if I can get away with it, the alternative is much more work, and less removable. But it seems to me that if you merely leave open the hole formerly occupied by the factory woofer, then add a rear-firing sub box, you wind up with a one-note wonder that vibrates the hell out of your trunk. The trunk thus effectively becomes a bandpass enclosure, with the factory sub hole as the only port to the car interior. Add to that the cancellation of the direct rear-firing wave with the wave reflected off of the back of the trunk (and sides, etc.), and it would seem like it's one hell of a boomy mess. Then there's the added problem of the varying "junk-in-the-trunk" (no, not J-Lo - though I wish I could carry THAT around in my trunk) causing daily variations in the trunk volume and materials, etc. and affecting the sound. Seems to make much more sense having the woofers fire directly into the cabin, a'la Sparky3's method, and it seems his experiments prove it.

Somebody tell me I'm full of it, and that their system is tight and clean and reasonably linear. Anybody???

biggie27

I have my subs firing to the rear at the moment, and Im getting ready to remove it so I can try sparky's method, my experience with the subs firing to the rear is that I do get alot of boomy bass, but the SQ levels are realy bad, the subs are not snappy for techno type of music, and they really suck at rock & role music. but they sound great in R&B and rap, where you need that boomy bass. Since I lisent to everything Im gonna try sparky's method and see how it sounds

sparky3

Guys, I work for a company that installs very high end home audio/video theatres, and some of the installers cannot believe how clean and tight the bass is, especially considering they heard it when I had the subs facing the rear. When they were rear-facing, all I heard was "gets nasty low" and "bass is very muddy". I cannot tell you how enjoyable it is to play all types of music and not have a "one note wonder" type of box. Go with a nice, large sealed box and get rid of some of that nasty rear metal...then seal it up. I have no reason to lie to you. I literally bought 3 different boxes and actually spent several hours with the subs facing all different directions on all different music. Very nice having a full trunk, too....

Shawn

engin_ear

iTrader: (1)

Thanks for the replies, much appreciated.
Shawn, I know you're not lying -didn't even mean to remotely imply that. I was just wondering whether there is some magic way to get the rear-firing configuration to work OK. But looks like I'm not going there.
Biggie - you're right - for rap, it seems preferable to go rear-firing to get the boom and vibrate the whole car (and neighborhood, for that matter). Your techno comment is especially well taken, because I listen to house and trance more than anything, but also a lot of R&B and jazz. House and electronica - contrary to popular belief - need clean, high power to sound right. If I decide to put on Frank Sinatra, however, it needs to sound like Tommy Dorsey's band and not Ludicris.

Just last night I did an experiment with a large home speaker cabinet with a 10" woofer, one that sounds very clean and snappy in my house. I rigged it up in my trunk and faced it toward the rear. It seems that all I heard was the resonant frequency of my trunk. When I faced it upward, the boom *mostly* went away!, and I could start to hear the intricacies of the notes. That was enough for me. Haven't started any of my work in the car yet, still preparing...

Jerry.

London Bill

I was impressed by Sparky's sub solution but I am also concerned by the removal of any metal from the rear shelf. This area does prevent the sides of the car from flexing, this may not be apparent at first sight but continual flexing due to weakening of this area could lead to distortion of the body shell.

I would suggest that some effort is made to replace the strength that is lost by cutting away the extra metal, a couple of flat steel straps fore & aft with another brace crossways across the new hole should suffice and will have minimum impact on the bass travelling through the shelf, it might even help reduce harmonics.

How many people have thought it is a real shame they never seem to make this area just "flat" as it would be easier to mount speakers in? The answer is that the undulations in the panel are designed to get maximum rigidity from the minimum amout of steel, that's why removal of anything in this area has to be done with some thought.

When subs are sunk directly into the rear deck and mounted properly with rigid fixings, this replaces the strength lost by cutting the holes as the circular basket will be as strong if not stronger than the original metalwork.

amlin423

Hi Shawn,
You have pics of your setup now? I have the diagram you drew me but I'd like to see the final thing...My sub is facing the rear right now...but i thought they sounded quite nice...haven't tried it facing upwards....thinking of getting free airs...

LexDriver18

Sup Guyz -

I was just wondering if anyone had thought about isntalling subs on the bottom of the trunk. Example. Take out the spare and build a box in the floor of the trunk??

Now I know I will lose all my trunk space but what do you think about how it will sound?? Boomy?? Tight?? Trunk rattle??

I just had some thoughts about it and was WONDERING how you guys think it would sound??

Thanks