rotarygod

As many of you know I worked in the car audio industry for several years. During that time I competed and traveled to many IASCA and USAC sanctioned competitions supporting the cars I built. I take pride in knowing that EVERY car that I have ever built has won in competitions including several world championships in both sanctioning bodies and a few even got into the magazines. I used to work with Matt Borgardt of Image Dynamics and I personally know many famous audio people such as Alma Gates, Gary Biggs, Mark Eldridge, Will Adcock (my old boss), Mark Fukuda, Eric Stevens and a long list of others. My crowning and final achievement in the audio career was winning an IASCA and USAC world championship 2 years ago at the same time as well as building a van for era marketing which turned out to be a massively loud Rockford Fosgate show van. I left the industry on a high note. Hopefully all that makes me qualified for what I am offereing to help you guys with.

I see so many people trying to cram overly huge boxes in their trunk in pursuit of bass and I can't figure out why. Bigger is not necessarily better and in audio this is almost always true in regards to subs. Many people want loud so logically they put in multiple woofers, and mega power all in the pursuit of loud bass. Unfortunately this means absolutely nothing! Prefabricated boxes are crap. Don't buy them. If you bought a prefab bandpass box with a plexiglass window in it just go ahead and shoot yourself now. Just get it over with. The more complex an enclosure gets the tighter the technical tolerances have to be. There is no magic box that works for every woofer. A sealed box is a safe way to go. They sound good, most woofers work well in them, they are cheap and simple. The key is finding one that is not made out of particle board, is not made out of thin wood, and is the proper airspace for the sub you have chosen. If you meet all of these requirements then you will be rewarded with decent bass. Next we have ported boxes. A properly ported box with the correct speaker sounds incredible. Unfortunately there is no perfect ported box unless the speaker manufacturer is selling it for a particalar woofer. Forget that prefab fleamarket ported crap. A ported box will have much greater efficiency right down to the frequency that it is tuned to. It also will handle much more power. Don't worry about tuning to 20 hz you don't need it. Typically I've tuned boxes to 35 hz with wonderful results and the owners never even knew it. It takes a few years of playing to fully accept how this works the way it does. Depending on the frequency that the box is tuned to will effect the overall loudness of the system as well as the type of music it sounds best with. That's right, I can build you a box around your music preference! The last box is the above referenced bandpass box. As with ported boxes there are no generic bandpass boxes that work for crap. If you want a big plexiglass ornament then go ahead. A properly designed bandpass box will only work for 1 woofer. If you change types you need to change boxes. It has more of an echo character and is really only useful for some rap music. With the technology of todays speakers there really isn't much point in bothering with this type with the exception of one design that I have. Other notable box styles are transmissions lines, folded horns, voigt pipes, freeair, and aperiodic systems. Don't even get into these unless you have tons of time, love to experiment, and live for disappointment most of the time with the very rare revelation of purity when you finally did get it right. Now onto why I started this thread...

As I said I will help you design the perfect box for your RX-8. If you live in Houston or are willing to come here I will build it too but remember time is money and I am a little short both so it would be cheapest to build yourself. There are some things I need to know from you in order to help you with a box design. I need to know what type of music you listen to. If you tell me "everything" I will probably respond with something like "opera, pipeorgan, Verdi, Bach, Beethoven, Metallica, Korn, Billy Ray Cyrus, and P Diddy?" The response is usually something like "except for _____ and ______ " and so forth and so on. Obviously this isn't everything so tell me what you listen to most of the time. Is it rap, country, jazz, rock, metal, etc. If it is multiple styles tell me which one you favor the most and then go down the list in order of importance. I also need to know which woofer you want to use, how many, and in what size. If you say more than 2 I'm just going to say put it in a sealed box as large as you can so limit it to primarily 1 or 2. I also need some info off of the spec sheet that comes with the woofer. If you don't have it then give me the model number of the speaker and I will attempt to figure it out. Off of this spec sheet I need; Vas, Fs (or Fo), and Qts. Everything else is irrelevant. Once I have all of this info I will send it through the computer and design the box accordingly and send it to you. I will not give dimensions. I will tell you internal volume, port size (diameter) and length. It is up to you to figure out how to make it fit.

As an incentive so I can learn the trunk dimensions, the first person to bring me an RX-8 to install a custom designed box in (by me), I will design, build, and install the box for only the price of the wood! That is less than $20!!! In return I want to face the box the direction I want it, port it if I want to, and I want feedback on this forum in the form of pictures and a review of its performance. I have never had any disappointments with my work and this is why I am confident you will be happy too. The results of that one box may turn out to be copied by many others instead of trial and error. I may even be able to arrange to have the car metered for SPL as well as have the system frequency response plotted on an RTA for all the world to see.

It is a good offer by me just to help out my fellow rotorheads. I hope that someone takes me up on it so I can show you all how it is really done

Kev

Hey rotarygod, great offer!

I'm probably about 12,000km too far away to take you up on your offer, but I'd appreciate your thoughts.

I've got an older JL Audio 10W6 (dual v/c) that I've never taken out of the box, and was considering a sealed enclosure of 18~20 litres (less cone and magnet space). I was going to set this into the floor cavity in the trunk and fire it straight up. (FWIW, Fs 23.2, Qts 0.432, Vas 65.1l, Imp dual 6ohm).

But something deep inside tells me that I still need a boot that can be useful...

So what do you think of the W0 6 inch subs...

Specs...

Nominal Diameter: 6.5 inches (165 mm)
Continuous Power Handling: 75 Watts
Voice Coil: 1.25" diameter, 4-layer, Kapton former
Available Configurations: 4 ohm or 8 ohm (Single Voice Coil)
Xmax (one-way, linear): 0.285" (7.2 mm)
Sealed Enclosure Range: 0.15-0.20 cu.ft. (4.3-5.8 liters)
Ported Enclosure Range: 0.20-0.33 cu.ft. (5.8-9.3 liters)
VRC™ Technology: YES

The small enclosure requirements would allow for some interesting designs.

That suggested, I've alway felt that you need at least 8 inches to be noticed - WDYT? I've had bass tubes that do very little.

I'm tempted to make a concertina box for experimenting!

Kev.

BTW, I'm concerned that the signal from the head unit won't be much good below 50Hz - does anyone have thoughts on this?

rotarygod

JL Audio is always going to be a good company no matter which sub line you choose. Even the W0 sounds nice. I used to have a 10W6. That is one of my favorite subs. I've also owned their 8W6 and 15W6 as well. I have done those in sealed and ported boxes. The 10W6 can be used in a really small sealed box and sound quite nice but in needs huge power to do so. If you want to go the sealed route you need a box that is optimally .66 cu. ft. internally. You would also need to take into account the fact that the woofer itself takes up airspace so in reality the box would be about .75 cu. ft. in size sealed. Thats pretty small. If you wanted to do this box ported it would be bigger, somewhere around 1.25 cu. ft. internally. If you could get this size and do it ported you would probably fall over in disbelief at how loud it can get. Yes it would still sound good. The myth that ported boxes sound bad is false. A good one is beautiful. Look at most high end home speakers, ported! The ported box doesn't need as much power but if you've got it use it. The final design I have is a readily available design that can be found on the internet if you look. It is a bandpass box called the deathbox. It is the exception to my rule of not using a bandpass box. This box can internally be adjusted to any car with almost any woofer after it has been installed in the car. Great box and still less than 2 cu. ft. The W6 may not be too happy here though so my recommendations are to stay simple sealed if you must or go ported if you can. You will need a good sized amp for the sealed box and at least a medium power one for the ported box.

There are 3 things that people typically want out of their subs.
1: Small size
2: Very low frequency reponse
3: High efficiency (doesn't require tons of power to get loud)

Of these it is only possible to have any 2 at one time. If you want a small box that plays low then you will have low efficiency and need tons of power. If you want low frequency response and high efficiency you will need a large box. If you want a small box that is highly efficient it won't play very low. Then you have to balance this out with your needs.

If you want to do something smaller like a 6" sub then I am getting the impression that you just want low end fill but not dominating bass. We have used very small subs in our showcars for sound quaity judging. When our Dodge Intrepid called the Reaper won IASCA and USAC world finals in the Expert 601+ class, we didn't even run the 3-15's in the back. All of the bass during the sound quality judging came from 4 Focal 5" subs mounted in the dash! If we really want to jam though we turn on the 15's but the point is made that a small speaker done properly can work beautifully. If the subs must stay in the trunk (not everyone is as crazy as I am!) I would stay with at least an 8" at the smallest. This is getting pretty small but 8's today can get pretty damn loud if they have to. I think the record for a single 8" right now is somewhere around 148 db. That is much louder than you think it is. I would like to mold a box into a corner of the trunk and fire the woofer out sideways. I could keep the box really small and the sound should come through really nicely. Even a 10" can be done in this way.

rotarygod

I was contacted with a point of concern about leaving their car with me so here's the details. I don't need the car overnight. You can stay and help. I am not installing an entire stereo system just building and installing a box. I don't even want to install the amp just the box. I will double check all the work though. It may take me 20 minutes to build one or 3 hours depending on how hard my brain has to work to get it right. We would need to set up a day to work on it. I would just like to be able to use an entire day if necessary. I will do it at my friend's shop since he bought the woodshop tools that I used to use back when I worked for Audio Designs. The table saw is about 10 ft by 10 ft across! We've got router tables, fiberglass, bandsaws, a drillpress, mig welder, and many other goodies should I need it. We can build anything there. So dont' worry or get nervous that you don't know me. You'll be with your car the whole time and can even help. I may even show you a couple of my custom rotary projects like the new engine and turbo, or the custom built intake manifolds. Just another rotor head doing what I can!

Kev

Acoustically I really like the idea of mounting an efficient 8in in the side and firing it across the boot. That's probably also the best space compromise - but it's also the worst for weight distribution in the car. (Another 2 out of 3 scenario )

I felt that 6's in the boot could potentially be a bit of a lost cause ... you've driven that home for me!

I'm not after thumping base, so the 10 in a relatively compact sealed enclosure with 250~300w to drive it could be perfect (I don't like it when rap music makes my teeth ache).

I'll show my ignorance here, I thought that ported enclosures were more often used when the sub wasn't mounted in a sealed space ... more a hatchback than a closed boot.

MrWigggles

Rotarygod,

I accept I can see you this weekend.

I will give you the rest of the info really shortly.

-Mr. Wigggles

MrWigggles

I Have already purchased a 10W0 4 Ohm.

It has the following specs:

Fs = 24.2 Hz
Qts = 0.400
Vas = 2.45 ft3

I would like to make a 1 cubic foot (internal volume) ported enclosure tuned to somewhere in the 30Hz region. Based on the work of Tom Nousaine, I want to then starting filling the box with polyfil while observing the results (the tuned frequency should go down signficantly while the effective box volume goes up). http://www.win.net/audtatious/audio/fiber.html

I have already purchase a 2" diameter flared aeroport tube (opening is 5" diameter) to be used for the port, I have a good idea where it can go, and I have a MTX311D to power the thing (155 Watts RMS). Also I think the box is small enough that we can get away with 1/2" MDF on the sides and 3/4" on the baffel itself.

Since this is fairly modest, you can already guess what my listening tastes aren't. I am not a rap fan. I generally prefer:

Classic Rock
80's and some 90's rock
Old school R&B - (Parliament, Steview Wonder, etc)
A little bit of classical
Some techno

PM me for more details and we can knock this out this weekend.

-Mr. Wigggles

BRx8

this is what i got for my car:



it takes up only a square foot and contains 2 8" Blaupunkt subs with an 140W amp and crossover built in...it hits pretty deep which is what i wanted...only cost me $140!

rotarygod

Sorry for not responding. I've been out of town for a few days. I'm pretty busy right now too so I'll respond to you all later this afternoon.

rotarygod

Kev: For you I'd agree with staying at the minimum an 8" but probably a 10". Woofers can be efficient or inefficient depending on which one you choose and what box it is in so 300 watts may be just right or not enough. Figure out the woofer before the amp. Don't buy either until you've researched it all. The 6" is a lost cause unless you want several of them. What really determines if a box shoule be sealed or ported really is dependent on the woofer itself more than where it is going. Sounds a little strange. I can make a ported box sound good almost anywhere just by changing the port length around the environment. An example of subs that work great in ported boxes but hardly for crap in sealed boxes are any of the current Rockford woofers.

Mr. Wiggles: We'll figure out a date that we can get together. I'll probably want just one afternoon with you to stare at the car and get a feel for what you really listen to and how you listen to it. The Aeroport may or may not be the way to go. I am really unique in that I build many of my ports from wood and router out the edges. Sounds like alot of work but sometimes I port the box sideways, up, down, forward, backwards, use 2 ports, 3! (know a great trick there!), you name it. I do square ports, rectangles, triangles, and I even helped an installer friend of mine do a port in the shape of the iron cross. Wood gives me the ability to make a port go around a corner or split in 2 inside the box with one port opening. I do some weird things when space is at a premium. I'll show you one box when we actually meet that I have never seen ANYONE else anywhere build! It is a ported trick that extends low end by almost an octave, keeps efficiency the same, and has more power handling! The box is very slightly larger than the regular ported box. Even the purist will think it is a sealed design. It would take too long to describe here though. We are going to stay away from the 1/2" MDF. 3/4" is preferred but I'll go down to 5/8" minimum. We don't want to hear the box resonating, we want to hear the sub. I'll work out your box specifics tomorrow.

BRx8: While I generally stay away from premade boxes, if you like the way your box sounds then that is all that is important. It's what sounds best to you and not anyone else that counts.

RX-8-Tobi

@Brx8:

If you want a small enclosure, maybe also have a look on this:

http://www.canton.de/www/index.php4?...30,cs200a,2,en

rgds from Germany
Tobias

eXentric

Greetings rotarygod and MrWiggles! I've been waiting to post to this thread for over three days now. Apparently there was a problem with the system when I signed up. I could read, but I could not post and even though it showed my name at the top, I did not show up in any user listings.

At any rate, I can post now.

rotarygod,

I wish I had been able to post sooner, but even so I don't think I would have beat MrWiggles (damn you!). I really wanted to get in on the free box build. But, hopefully I can benefit from the design. I know MrWiggles and I don't share the same interests in music so it isn't likely...

Have you guys gotten together yet? If not, is it possible that I could join ya? I live up near the Woodlands mall, but I'd like to join and observe and learn. I'm a software engineer and I work on the west side of town. I don't mind traveling to wherever you're going to be at and I'd like to learn a thing or two about box design.


MrWiggles,

Damn you man!!! lol. I'm just kidding. I was hoping we shared the same interest in music, but I read again and realized we dont. Oh well. I have two 10" AudioBahns running on a 1000 watt mono amp (I'm sure not RMS). It's probably too much for this car. I just traded in a 1998 Mitsubishi 3000 GT and it sounded pretty good in there but I had to build a custom box for that car too and I don't think I was able to give it enough air space. I listen to some rap but mostely alternative. Linkin park Meteora and Linkin Park Reanimation are two of my favorites right now...


Anyway, let me know if you guys already did this. I'd like to see the finished product. Glad to get to know some locals. I read the other threads about HPD and such and I have to say I'm in complete agreeance.

Well talk to "Ya'll" soon. :p

eXentric

P.S. I'll swap better contact info via PM if ya want.

And rotarygod, if MrWiggles won the "Houston" contest, I'd still be interested in paying you to design / build me one too.

rotarygod

We haven't met up yet. Damn you are close to where I will be working on the car. Right across the freeway in Oak Ridge North. My friend John has a place out there that while not a business, does have enough room inside for cars and already has a fully functional woodshop. He does installs out there as well as other custom work. Right now I am helping him design and build a box for 4 JL Audio 12W3's. It is a box in the bed of a truck firing through a cut through. The box will be 2 chambers ported. He has 2 JL Audio 500.2 amps. It should be nice and loud. He likes to jam and isn't a purist so we are designing this box to be tuned at 35 hz even though JL recommends 30hz for the size box we are building. When I run the frequency plots on the computer it just shows to be a nice gain above 35hz. You would probably be the same way when it comes to box designs. Everyone wants a box that goes down practically to DC but wants it to be loud. Most of todays music doesn't go that low so why design for that.


Anyone here can give me a call on my cell phone anytime they wish (almost) at 281-386-6865. If you call just identify yourself with your forum name (ex: "This is ______ from the RX-8 forum")so I know who you are.

I'll still build anyone a box but obviously I need to eat too so I can't build everything for free. Sorry. I just got sick of seeing big generic boxes thrown in such a beautiful car.

eXentric: You wouldn't happen to have a yellow RX-8 would you? I saw one at Home Depot in the Woodlands one day.

Fred

rotarygod

One more thing. I am busy almost every weekend until Thanksgiving but have free time during the week. If anyone wants to get together for the initial build or to discuss your own project just let me know and we'll arrange it. Wiggles, we need to set up a time.

It would be cool to have a nice little RX-8 gathering. Too bad I don't have one yet The 1st gen will have to do.

Visa

Nice to see we have a specialist from the Houston area posting on the forum

I'm definitely looking at getting some subs in the trunk, couple of 10's or whatnot... but I haven't even figured out which ones to get yet, which makes figuring out what box for em kinda difficult

Looks like I have similar tastes in music as eX, mainly rock with some rap here and there. After I figure out which ones to get I'll definitely be lookin' into contacting you sometime.

eXentric

Cool Visa.

rotarygod was kind enough to tentatively let me stop by on Monday and show him what I had in mind. When we figure out what the setup is going to be like, I'll deffinately get in touch.

I still have to go get the specs on the subs I have right now. The speaker box is in my room and I just need to pull one of the subs out and get the model number so I can find the technical info on them. I'll post it here in a few.

Sounds like this is turning into a Houston forum! Heh.

Later guys.

MrWigggles

That was my RX-8. I work accross the street.

I will give you a call. I sent you an email and a PM last Friday so you should have my number as well.

-Mr. Wigggles

eXentric

Yeah, mines a black one. I just got it a week ago.

I finally pulled out my subs. They are ALUM10X. Here's the specs I could find:

Size: 10 inch
Rec. Sealed Box Dims: 0.25 - 0.75 cu.ft.
Rec. Ported Box Dims: 1.24 cu.ft.
Free Air Usage: not recommended
Sensitivity: 95.6 dB
Frequency Response: 20-500 Hz
Recommended RMS Power: 800W
Impedance: dual 6 ohms

I have two of them and I bridge all four channels down to the mono amp, so I guess I am running at 1.5 ohms. But, I know that's not what you care about

rotarygod

Man you guys are going to make this easy. I live in Spring and the place I build everything is only a few minutes away from that Home Depot in Oak Ridge.

eXentric

Yeah. I think we really should do a north-side RX8 get-together sometime. rotary, we'll take turns driving mine around that day if you don't get yours by then :p

Any of you other guys like Halo? I know rotary doesn't, I already asked him.

I usually have several people over most any weekend and play. I'm pretty happy with my setup here, which includes a nice 6.1 setup and a 137" projection screen. When I'm not driving in my RX8, I'm usually attached to a controller or keyboard and mouse

If you have a mod chip and play Halo, you might be familiar with my program 'Cartographer'. It was the first publicly available map hacking program for Halo on the XBOX.

If any locals want to play - modified or un-modified - let me know!


*** And P.S., anyone in Houston can come over and see my original copy of Halo, so let's not start up the tiresom conversations about modchips. This is, after all, a thread about designing good boxes.

MrWigggles

eXentric,

I play a lot of Halo usually on only a 100" screen. I also bought it for my PC but haven't played it yet.

You should go to AVSforum every now and then.

-Mr. Wigggles

eXentric

I just learned about the AVS forum today interestingly enough. I've been on it all evening. Thanks!

100" is pretty damn close to 137" when you're talking at that scale

We should play sometime. I have HPC also.


But, alas, I think we're cluttering up poor rotars thread. We should probably PM any more Halo stuff...

rotarygod

Hey wiggles are you and Jared (exentric) going to be free Sunday? I'll be up at the shop working on a box and it is a perfect time to go over the design.

wiggles: What the hell is your name? :D

eXentric

Oh, that would be even better man. I can leave work early on Monday, but I certainly have time on Sunday too. I'll call you tomorrow. What time? I don't usually get up till around 11, but just let me know.