zedex

I know a few of you are pretty heavy into good sound. Heres my situation. I have 2 12 inch cerwin vega subs in the trunk of my 68 mustang. I rarely drive it so i might as well pull one of the subs out and put it in my tacoma. Heres my question. I made my sub box about 10 years ago and i think it has about 4 cubic feet of airspace with 3 16 inch tubes for resonant frequency.(each tube i believe is 3 inch diameter) Does anyone know how i should convert a box size and tube size to accomodate 1 12 inch sub instead of 2. Also wondering if i can port the sub to draw airspace from outside. I know old HART speakers you could port the box to the outside. I used to be pretty up to date with the audio aspect but in my old age im a little out of touch. Any ideas? Much appreciated.

Los Gatos?

Box design is, unfortunately, more complicated than just adding holes to a box hehe. It would be better if you could find out exactly what model you have, and even better, if you have any of the T/S Parameteres (Thielle-Small I think it is) If you can at least get a model name/serial I will try to look it up and model up a nice ported box for you. What kind of amp would you be using with this? Are you using a subsonic filter (you should be if it's ported) and is that on the amp you are using for the 4Runner? Are you handy enough to make this box yourself (if not I have a good box contact) If you can at least get some T/S params for me I will try to model a box for you. Even a model #/name would be enough probably. Thanks!

zedex

Thanks Los Gatos. I will get you the model # of the speaker. The amp i will be using is an alphasonic 2075 i think it is.(75w per channel) The head unit is a nakamichi cd45z. I can also use my other amp which is an alphasonic 2100. Not sure if those amps have a subsonic filter. Building a box is no problem. Im running a couple vifa tweeters and vifa mids. as well as 2 stock toyota garbage speakers just to even up the sound a bit.
Like i said about 10 years ago a friend of mine had a program so you could just punch in your speaker model # and the program would work out the box airspace, tube length, tube dia, for the specific resonant frequency you would want. Then i just build the box to fit the mustang. We have since been out of touch and moved. I appeciate any help you can provide me as my Tacoma low end is non existent.
Thanks again. I will dig out the sub with model #.

zedex

Heres the # on the sub.
Cerwin Vega LE12S

Cabinet Serial #LE033268. Thanks for any info you can find.

Bumpin' Yota

I sell custom boxes as a hobby, but if you need any help dont hesitate to ask.

ps - read through this link, there is a LOT of good info here about box design and how they work.
https://www.yotatech.com/forums/show...threadid=11314

this is a link on sound insulation
https://www.yotatech.com/forums/show...threadid=11179

Los Gatos?

Man I can't seem to find a complete T/S listing....must be an older model I guess? Well.....it looks like if you want ...

Low Bass:
1.2 ft^3
tuned to 33hz

Loud Bass:
1.5 ft^3
tuned to 49 hz




Well, that took a while...I must say these subs don't model how I like them to lol...the other problem is that I don't have all the specs, the program I used, WinISD couldn't calculate any port dimensions without the Qes/Pe, which I could not find online...maybe bumpinyota can help you, I've done my best and failed miserably

zedex

Thanks Bumpin. I did read some of that link. I think most guys(younger guys) want a big box so that your bass drives the seals out of the windows. Been there, done that. What i want to do is have a box very shallow and as small as possible. I dont want a big box in the back of my truck. I dont know if you have ever heard of this but. I remember about 15 years ago HART speakers were pretty popular. Small size. Relatively good bass. What you could do with these is, you could build a box for the sub. Just big enough to enclose the sub. Then, you could port the box to the outside of the vehicle as in cut a hole on the floor or wherever and port the box outside. What i want to do is put a sub under my seat and hopefully port it outside. Im not after the boominess factor in fact i dont want that. I want good low end and thats it. Even so so low end would suit me fine. Im not going to be river crossing or in any water so im not worried about cutting a hole in my truck. Im a steel fabricator/cabinet maker and a few other things by trade so building something is not a problem. Im just not up to date on what you can do these day in respect to box size and design. If i have to build a steel box that gets bolted to the underside of my truck i will do that. Maybe there is a way to port one box into another box thats mounted under the truck? I dunno. Any ideas?

zedex

Thanks Los Gatos. You didnt fail. Very appreciative on what you did find. You are right. These subs are at least 10 years old.At Least!! If i have to go out and buy another sub i will do that. But i should be able to use one of these. And you get an idea on what im trying to accomplish.

Los Gatos?

These subs look to be VERY VERY "ported use only" hehe....I will poke around and see what else I can find out...there's probably a way to get these set up how you want. The problem with porting to the outside of the vehicle is that's where all the sound will go hehe. Maybe it worked great for those hart subs but I dunno about your vegas. YOu might want to pick up a cheap sub and run it sealed off that amp you have....there are some excellent subs in the 80-125$ range. The Pioneer TSWO5 (or whatever that is lol) is a good value, it's like $70, works good in a small sealed box which is what you want basically. For 125$ you can get an elemental designs 12k or the new sub, the 12O, both of which are good in a smallish sealed box...depends on how much money you wanna spend I guess

zedex

I talked to a guy around here who used to sell HART speakers and he told me he had never heard of porting HARTS or any kind of speakers to the outside. I tend to think he is right. He also said the way to go would be do what you said and buy a different sub and fiberglass the back of the tacoma under the fold down seat. (theres a compartment there). I really dont want to do that. I would rather have a sub under the drivers seat or passenger seat and if possible port a sub to another box mounted under the cab . I dont know if thats possible to port from one box to another. If not i guess my only alternative is to buy another sub and fiberglass that storage compartment. The problem i have with that is the stink of fiberglass for a long time. Maybe fiberglass loses its smell after a few weeks. I dunno. And also i didnt want to modify the storage compartment . I really appreciate the time you guys have taken on this dillema. I think the 12 inch subs will have to stay in the car.
If i do decide to buy another sub. Any thoughts as to what brand. Im running vifas right now with nak. I like a real sweet smooth sound. Not harsh like lots of lower end speakers. I may even pull the KEFS out of the mustang and use those as my tweeters. Any thought on that would be great.

Rymin929

I would have to agree, I havn't heard of porting a sub enclosure to the outside in my 11+years in the biz. I have a single 8" built into my storage compartment, but like you said that doesn't sound like an option.

The only other enclosure that I've done and it was a reg. cab was to build a bandpass enclosure under the bed and port it into the cab, still have all your space and sounds awesome, plus less limited on woofer size.

I have access to box building programs but I'd need the Thiele-Small parameters like Gatos? in order to come up with a bandpass or vented enclosure design.

zedex

Hi Rymin. YES. The bandpass thing sounds like a plan. Thats exactly what im aiming for. I dont know what the thiele thing is. Im not familiar with that term at all. But i think there has to be something that will work with one of those 12s or buy another and use the space under the drivers seat.

Rymin929

Here is just an example of what we were talking about, it's on the 2nd page of the acrobat file.

http://jlaudio.com/subwoofers/pdfs/10_12W6v2_MAN.pdf

These are just basically the mechanical/electrical layout of a woofer(speaker), and assists in designing the enclosures for them.

zedex

Thanks Rymin. Im gonna look into that sub today. Hopefully it wont break the bank.

Bumpin' Yota

thus far I think everyone has pointed you in a good direction.

on the HART(?) subs, I think they were shooting for a true Aperiodic Enclosure. Basically it is a TOTAL sq box, however the port to the outside must be slightly obstructed with fiberglass fiber or some form of polyfill. Adjusting the amount of the obstructing material yeilds different results. You would also need a good equilizer to fully pull out the lowend as boxes like this are lacking below 40hz. Addtionally such a box ported to the outside (as all true AP enclosures should be) would need to be fully waterproof (read fiberglassed) even if you don't do river crossings and such. This box when properly used and installed is probably the best box for sound quality bar none.

Another thing you can do, IF you plan on keeping your truck till it dies, is a cut through. Basically you affix a tonneau cover over the bed, then cut out the front of the bed and rear of the cab, leaving the window and structural support beam below the window. Then just get some gasketing material and seal it up. then you have your ENTIRE bed to dedicate to sound.

BTW - fiberglass looses all smell within 3-4 days. Besides the fumes are fun ...just try not to think about all the brain cells you kill when you get lightheaded from the fumes....lol

The fiberglass custom box is a good bet, however do it yourself, and don't let a shop charge you 1200+ to do a custom box.

zedex

lol. Thanks Bumpin. I have done fiberglass before. And yes. The braincells do get scorched. I need to save what i do have for a special occasion. I have a feeling though that the fiberglass is gonna have to come out of storage and be put to use. I hate that stuff.

zedex

Just to fill you guys in on what i found. I ended up going to the place that originally sold me the cerwin vegas. Using those in my truck is futile. If i try to use the cerwin vegas i will end up with a tacoma speaker cab and not a tacoma extra cab. What he suggested to me is the NEW bazooka rs series subs. He says they are a very impressive unit. Not the old bazookas, the new RS series i guess they are. So. Instead of modifying my truck just to get some low end im going this route. Any one here use one of these subs?