NZConvertible

It's just not that easy. The box must be matched perfectly to the sub you use or its performance will be seriously compromised. Unless you find someone using the exact same sub as you, you can't use their box specs. Things like internal volume and port size cannot be guessed, and are usually calculated using computer programs and the specs provided with the sub. You might find that the sub supplier has this software, and can recommend which type of enclosure is best for your application and calculate its requirements.

RX-Heven

iTrader: (1)

You will never fit the "ideal" subbox under the spare tire cover. It really doesn't need to be that complicated. Sure, some sound quality will be compromised, but most of us wouldn't be able to tell the difference imho.

vaughnc

I'm planning to use Kicker Solo-Baric 8" subs due to the optional OEM small box size, output|weight, square=larger speaker cone size in a smaller space, and lighter overall weight.

Haven't decided between the L5 (300 watt consumer) or L7 (450 watt competition) grade Solo Baric's though. I'd rather just use 1 sub if possible.

Fabbing up some mounts for the subs isn't that hard, but figuring out correct positioning for optimal sound & "punching through" the cardboard spare tire cover are challenges to overcome.

These subs aren't the most effecient, but they do put out good SPL and in a car environment clear bass at very low volumes isn't really a concern (effeciency). Not sure how much volume/SPL you can really make with one 8" 300 or 450 watt sub. Plus the OEM box @ 0.66cu/ft robs some SPL due to the small size (you can make your own box larger box in the 0.8 - 1.0cu/ft range, but then you might as well by a cheaper sub then as any sub fits in this sized box).

Should sound great with the top up, but I want clear, loud, accurate, and 0 distortion @ 80MPH with the top down... which may require 2 8". Note I had HEAVY Dual 10" subs in my Mazda 929, and their weight+box weight threw off my handling & reduced my power:weight a bit. I'd like to avoid this in the vert.

http://www.kicker.com/ShowPage.cfm?f...enu=SUBWOOFERS



The other consideration is amp weight. I'd like to use one of the "all in one" amps with 4-6 full range channels+ 1 sub channel... and having gain controls & bass boost on each channel would be nice.

It's way too temping to move up to the "fully electronic tuning" offered in the mid-high end receivers, amps, & subs... and I'd like to ditch the analog pre-amps as well if possible, but that can get costly very quickly.

RX-Heven

iTrader: (1)

My system is not complicated. I have two amps. One (alpine) to power the four 5" speakers (Boston) on the spare tire cover. Another amp (JBL) to power the sub (JBL) and four door speakers (two each door; Boston). The headrest speakers do not work as they were blown out LONG ago. The stock "subs" also do not work. They are pieces of shiyate anyways and could hardly be called subs plus they are in the worst location. I have an Alpine CD/mp3 player as a head unit and an Apline CD/mp3 six disc changer. The head unit of course controls everything. I might post more pics later as I will be working on the car anyways and maybe I'll take more pics, those earlier are just what I already had.

RX-Heven

iTrader: (1)

Here are some good links to pics of other vert installs. v8rx7's is probably the nicest imho and I have heard it. Also he has a very comprerhensive write up of how he installed it. Very good site. Sounds just like mine btw

https://www.rx7club.com/forum/showth...&threadid=9211
http://v8rx7.com/sound.htm
https://www.rx7club.com/forum/showth...hreadid=108314

RX-Heven

iTrader: (1)

Here are some good links to pics of other vert installs. v8rx7's is probably the nicest imho and I have heard it. Also he has a very comprerhensive write up of how he installed it. Very good site. Sounds just like mine btw

https://www.rx7club.com/forum/showth...&threadid=9211
http://v8rx7.com/sound.htm
https://www.rx7club.com/forum/showth...hreadid=108314

STR8BALLIN - R

it appears that boosted7 built his own box. i guess i will pm him and try to nab some info off of him.
i undertand i probably wont be using the sub to its full potential under the rear hatch and with a home-built box but like i said before. it looks like a couple of the guys have done it and i doubt they have all this high tech computer system gizmo whatever as was mentioned above.
i havent purchased my sub(s) yet so if need be i will buy the same as one of them have or something with very similar specs. i guess.

sub9lulu

iTrader: (7)

thanks a bunch, that helps alot

NZConvertible

That depends entirely on the sub used, the box's design and the skills of the builder.
Actually it is very complicated and most people don't have a clue about it. anyone who thinks it's just a speaker in a box is very mistaken. If the enclosure and port dimensions aren't right you'll get a small range of frequencies played very loud and very little else. This will make pretty much any music sound bad.

It's just computer software, and without it the chances of getting quality sound (as opposed to just volume) from a sub are slim. If you're lucky enough to find a sub with box and port sizes on it, stick to those dimensions, because they will have been found using that software.

I strongly advise you talk to a professional about driver selection and box design. Any decent shop (i.e. not a budget chain store) will be able to do this for you.

STR8BALLIN - R

Nz you aint makin this process too easy for me. I am the kind of person that if i hear advice like yours and totally oposite views from others i get caught up in my decision process...
just curious about what you did (orhad done) with your audio system.

NZConvertible

Just because someone has done this in their car, that doesn't make them an expert. The best advice I can give you is to talk to a professional. I am not an expert at this, which is why I have regular discussions with a very experienced acoustic engineer who also happens to be a home theatre enthusiast and likes to build his own speakers. I've also done a lot of reading over the years about sub enclosure design, so I know enough to know that if you want good results, it's not a job for novices.

I'm currently running 4" 2-way speakers in the dash, 6" 2-way speakers in the doors powered by a 200Wrms 4-ch amp and a Clarion head unit. I'm toying with the idea of running the headrest speakers from the head unit's internal amp but can't be bothered pulling the dash apart to get to the wires. Eventually I plan to add a 10" sub in a vented box, which will be designed by the above engineer.

RX-Heven

iTrader: (1)

I didn't install my stereo simply because I wanted it to work and I am certainly no expert. My friends stereo shop did it for me and even with the bro discount the sub box still cost me $300 due to design and labor costs. Double that and then some for a regular joe. My friend did not even want to put a sub under the spare tire cover because he and others at the shop said there is no proper way to design a box in that limited space. I insisted and they were surprised at how well it sounded and I am certainly happy with it. I have heard several verts with 10's and one with a 12" sub. All of them were homebuilt systems and they sounded great with the exception of the car with the 12". I'm not flaming, but when you get a 10" sub eventually designed by your sound engineer friend and his software, I bet my system that it doesn't sound any better than mine or some of the other vert systems I have heard.

NZConvertible

Home-built is different to home-designed. I have installed quite a few stereos and can handle the fabrication of a simple sub box, but designing the box is a whole different matter. Most people have no idea how complex acoustics is.

The difference between a box sized at random and one designed using sub enclosure simulation software can literally be a doubling of the noise output, or a sub that can effectively only produce one note instead of a covering a range of frequencies.

Go ask your friend how he sized your box and port (if it's vented). I guarantee you there was very little guesswork involved. Any serious installer will be using software or staying as close as possible to any recommended sizes from the speaker manufacturer.

STR8BALLIN - R

I have heard of a few proffesional installers on the board, so they may have this software to make the super crazy sounding concert hall sub box nz is talking about. if you are lurking speak up. i want you to plug in some numbers.....

if not, i think i will talk tosokme people who ahve built their own and consult some audio places and the manufacturer of whatever sub i get and built my own... again, i just want some thump and a sub combined with new rockford speakers all around running off an amp and a new head unit has got to be better than the stocker equiptment that i am used to, so be it!
im not looking to enter competitions or have the sickest sub setup in the world, im sure this will far surpass stock and thats all i care about.
nz...do you by any chance get every last drip out of a pint at the bar.....every one?

STR8BALLIN - R

V8RX7com

I'm using my head unit's built in power for my headrest speakers. My head unit also has an EQ feature so I can take out the bass frequencies from the head unit's built in power. Since there is no bass going to the head rest speakers they don't distort.

Here is a couple of pictures of my setup that I installed in 1999:

NZConvertible

Just in case you think I'm making this up (and I think you do), here's just the first page from a quick Google search...

http://www.ht-audio.com
http://www.ajdesigner.com/speaker/index.php
http://www.loudspeakers101.com/AudSoft1.htm
http://www.pvconsultants.com/audio/boxmodel/subsim.htm
http://www.caraudiohelp.com/subwoofe...e_software.htm
http://www.mobiledynamics.com/software.html

The stuff is very common. Some of it is very expensive, some of it is free. Any serious professional stereo installer will have something used to design speaker boxes.

So it sounds okay? I thought about adding simple passive high-pass filters and a stereo volume control to the internal amp's outputs so I have control over how they sound. I don't want them to upset the sound from the main speakers, just enhance it a bit. You may have rekindled my interest in this project...

13bpower

My old vert. I moved the spare to the trunk. Sounded really good. Zero chassis/trunk rattle.

V8RX7com

What I did is:

I used the head unit's "rear" pre-amp outputs for the amps and I used the "front" speaker outputs for the headrest speakers. this way I can also use the fader on the head unit to adjust the head rest speakers volume.

How do they sound?:

In my case .... I'm running so much power from my amplifiers. you don't even notice that they are there .... but then again, that is what I was trying to achieve.

STR8BALLIN - R

what dimensions is that box. i would have thought two individual boxes to be better than one/
Nz...i believe you, i just dont want to spend crazy cash ( which i dont have) on a custom designed install if i can figure out a way to reasonably do it my self, again, i know it wont be an optimum set up and again i dont really care. But i do believe you. Thanks for the input bud!

STR8BALLIN - R

isnt good enough to build a decent box?

http://www.crutchfieldadvisor.com/re...build_box.html

13bpower

I did build it myself. It took a few hours of planning, measureing and computing air space, and then a few hours of building, then a few more getting it to fit right. If you look closely at the top right of the pic you can see I had to grind off the corners of the box to get it to fit. Also factor in about an hour with a "nibbler" to cut the spare tire bracket out.

I do not remember the dementions, but it is one sealed box. 2 JL 10" W3(I think) subs. The airspace came out to exactly the recommended amount for the subs.

I all fits easily under the stock cover.

NZConvertible

I'm quite sure that any decent stereo shop will help you design a box if you buy a sub from them. They may charge you a small fee, but it'll be worth every penny. Every sub is different (I can't stress that enough) so the sub's particular specs, called its Thiele-Small characteristics, must be used to get the box right. All you need is the box internal volume and (if it's vented) the port's diameter and length. Then you can build the box yourself using those dimensions. I'm not suggesting you get someone to do the whole lot, only that you get an expert (or software written by one) to do the bit that can make or break a system.
I've heard some subs set-ups built by people who didn't understand how subs work that sounded truly awful. I wouldn't want you to go to all the effort of building and installing something that sounded worse than before. But hey, if you don't care then I'll just be quiet...

STR8BALLIN - R

the link i gave above has all the calculations required to calculate the internal volume of a box so i really do not see what the big problem is if that is all you think a professional needs to be involved in the process for. It appears to be some number crunching and some adjustment. Speaker companies most often give you the optimum internal volume of their sub. sooo. you measure out the size of the rear well and do the calculations for internal volume, crunch numbers and adjust and voila!
I have found numerous websites with equations on how to figure out the internal volume when building a box and everything.
So my question again, is what do i need the pro advice for?

NZConvertible

Any kid who went to school should be able to calculate the internal volume of a box. I'd be pretty worried if you couldn't. That site does not tell you how to match the volume of the box to your chosen sub. In fact all it says is "The manufacturer recommends a box volume of 0.6 to 1.25 cubic feet." Yeah, that's precise...
Generally all they give you is a ballpark figure for a sealed box that'll make sound that doesn't suck. If you want a vented box (which tend to give better results depending on the application) then that info is useless.

I don't understand why you're so reluctant to even investigate something that'll cost little to nothing and add maybe 15 minutes to the time you take to buy the sub. You're making it all sound much harder than it really is. Buy sub, get seller to calculate ideal box volume, calculate dimensions required for that volume (just like that site says), build box.