Zach McAfee

The search engine sucks so I couldn't find anything on this (it won't let you type "8" ):

Has anyone tried fitting 8" subs into the stock shock towers? If you take out the stock box it fits perfectly, but I'm having trouble sealing it up. Any suggestions? Should I not worry about it too much? I don't really need a booming system, I just want some better tunes for the commute.

The current setup including the subs is:
2 4" component voice coils
2 3/4" Alpine tweet tweets
2 8" HE Rockfords (400W max)
Kenwood PS300T 400x2 amp for the subskies

Thanks!

MIKE-P-28

iTrader: (1)

Silicone, duct tape, fiberglass anything that will seal the holes and make it appear like a box.. Also stuff it with darcon polyfill and hope it sounds decent with no rear midrange or highs...

Zach McAfee

Hey, I didn't say I wanted surround sound

Thanks, I'll give it a shot tonight. FYI I'll let you know how it goes.

Damn Swede

I fiberglassed across the giant gap on the fender side, then siliconed up the various screw holes. You may also want to caulk around the rubber seal in the bottom of the tower for a sure seal.

Be sure to check the volume required by the subs, my 8's need .4 cubic feet of air volume, but I measured the tower to only contain .2. So I have to fabricate the extra air out of PVC pipe that is sealed at one end and connected to the tower to give the extra space. I'll probably tuck it away in the empty space in the fender so it'll have the stock appearance, but have some punch that'll leave the passengers wondering where the sound's coming from.

Damn Swede

If you are missing the highs/mids, you can always stick a set of tweeters on the tower itself facing forwards with a little bit of cutting up the carpet, but that's a whole other thing.

Zach McAfee

Thanks for the help. I got the subs installed but I havn't hooked the amp up yet. I'll do that during my lunch/work on car hour . They barely fit underneath the stock speaker covers, but I love the stock appearance.

I'll think about getting a component set or something for the rear. I have a factory hatch cover (aren't you jealous) so it'll be a little tricky finding a good spot.

Zach McAfee

Ok, the amp is hooked up and everything works, BUT the speaker covers rattle like hell. Also, my amp is "tuned" for my old 12" XLCs. There are a few variables and I don't know where they should be for my new 8 inchers.:

HPF Frequency (Hz)- adjustable from 50-200. (currently 50 Hz)
LPF Frequency (Hz)- adjustable from 50-200. (currently ~75 Hz)
Balanced or Unbalanced switch? (currently UB)
Opperation mode - stereo (no), Mono or Tri-mode.? (currently Tri-mode)

These are 8 ohm subs and they are bridged. I need some help. I'm an engine guy not car stereo! The subs are very responsive to "thumping" bass but not so much for the rest of the low freq. range. I guess I should turn up the high pass freq? As far as the rattling speaker covers, I guess I'll just put some insulation all around the metal tower. I'm good at finding rattles anyway (except for the rattles in my head).

Again, thanks for reading and responding.

Zach McAfee

Bumpity bump. anyone?

Damn Swede

Did you seal in all the holes?

Icemark

If you are stuck on the concept of 8" speakers in the towers (which has been covered before) anyway if they are completely sealed you have around .25 sqFt in there.

So if you want them to reproduce anything meaningful you'll need to have them crossed over at around 120Hz if you are using them as a sub, or 1500Hz if using them as a full range.

If you have them wired together, then you are stuck on setting the amp for mono. Trimode would be if you were using them with a full range pair speaker set up.

Damn Swede

I measured mine to be about .19 cubic feet. I'm not sure if different years had different tower sizes.

Make sure the covers are screwed on tight, and maybe even get some foam and place that between the cover and any metal that it touches. You should get some sort of a crossover/equilizer to get rid of the frequencies that the speaker can't play. Go to a Radio Shack or a quality stereo shop and tell them the size of speaker you're using and the frequency you want it to cut off at. They'll give you something that looks like an oversized capacitor that you put on the positive wire before the speaker and it should make the sound much more clear and defined.

Zach McAfee

Ok, I set the LPF at ~120Hz and it sounds much better (more mid range bass e.g. basslines rather than bass drum hits). I think I'll buy some of that poly-fill stuff to make the speakers "think" they're in a bigger box. I'm also thinking about buying the spray rubber coating stuff for the inside of the tower. I have a rear strut bar so it might be a little messy.

Icemark

I fiberglassed the whole tower and then filled it with water, and based my measurement by that.

It was really like .2368 sqft, so I just rounded up, but I imagine with the speaker in there it would have dropped down to your figure.

I was convinced that I could get real bass out of there, but sadly I was mistaken. But the best I ever got was using some Audax 7" woofers (that I doped the cone and put a small silicon bead for vibration elimination on the cone) and a small 1"ID port tuned to around 45Hz or a $175 (at dealer cost)ScanSpeak 8", found in some of the high end home speaker manufactures sealed.

jabbadeznuts

for the best sealant use GE silicone caulk. This stuff comes in many colors (silver, clear, white) and stays on FOREVER!you won't be dissapointed.

fastrotaries

so can you get any bass form that set up? I was thinking some upper bass, lower midrange stuff.

Icemark

You won't really get much below 80 Hz, so depending on X-over its possible to lower midrange out of it, but not true sub freqs

Zach McAfee

I'm not really concerned with hard hitting or extremely low bass. My dad bought an Audi a few months ago with a 10? speaker Bose system, and I got the urge for some good stuff in my car once again.

In my old GXL I had 2 4s, 2 6X9s, and 2 12s, but I got out of the sound thing after high school and after getting into autoXing more.

Now I'm looking for good sound that fits in the stock speaker locations. Am I getting old? Next thing you know I'll be selling my RX for a minivan. ugh

Icemark

Nah... not getting old, just growing up

I am a firm believer is stealth systems, and using the stock locations on most cars. Now competition sounds systems are another thing, but if the owner is gonna dump $5000+ plus into the system a little custom work is expected.

95R2-89TII Ground Zero

I thought about doing that when I was into stereo ****, but then I decided that it would stage improperly. So I opted to put 6 twelves in the hatch, and then 6 1/2's all the way around. You can run free airs though.

Eric89GTU

SIX TWELVES??? please tell me this is a typo... although it is kinda funny to imagine that many woofers with enclosures in such a little space...

Eric

hawk 7

iTrader: (2)

Do you think you could get decent bass out of the shock towers if you used a small sub like the JL 6w0's. They only require 0.15 to 0.20 cubic feet in a sealed enclosure.

Icemark

the 6w0 wants at least .20 sqft to work, which as mentioned above would be hard to get with the woofer in there.

as mentioned in other threads, you would be better off using the JL VR C650 or one of the MBquart 160mm woofers, rather than a sub woofer

Zach McAfee

I read the book on the Rockfords, and they make more of a thumping and less full range bass when the enclosure is too small. Uhhh yup yup thats what my subs do yup yup.

I'm gonna buy some of that poly fill stuff that makes the sub think its in a bigger box (sound waves travel slower).

meximan

iTrader: (37)

just kind of curious but, everyone is using silicon or fiberglass to insulate where the speaker mounts to the tower. Just throwin this out there but i have used this in a number of my installs. "Weather stripping" yes the foammy stuff that has done nothing but miracles on rattly noises on hard contacts.

Now this is the 8" sub thread. from personal experiences. would running an amp to a 6 1/2" work just as good or is there a significant difference between? Also for those mounting 2 -8" subs in the towers. were you also runnin a multi channel to the fronts? currently i have a crappy dual sub with a mono amp sitting in a box in the back of the car. with a good deck i think that it makes for plenty of bass for such a small car. I am looking to save myself the room in the back and to keep from drawing attention to whats inteh back of the car. I dont want to overpower the mid range in the car by throwin 2 8" subs in the back. opinions?