F-Body Ideas - Camaro and Firebird - Page 12

JasonWW · 10-17-2006, 01:29 PM

Does anyone care about the cable parts and how to make it longer? With no screen, I'm doing other things right now, but I can whip one up and take pics just to show how it's done.

eddielb · 10-17-2006, 01:56 PM

you found a way to make the cable longer then? Are you going to be using FM at all or just MP3s? What other things did you impliment on your system? Is there a way to use an aftermarket headunit just as the FM receiver but be able to change the stasions with the touch screen?

JasonWW · 10-17-2006, 03:13 PM

Quote: Originally Posted by eddielb

you found a way to make the cable longer then? Are you going to be using FM at all or just MP3s? What other things did you impliment on your system? Is there a way to use an aftermarket headunit just as the FM receiver but be able to change the stasions with the touch screen?

Yeah, I can make a longer cable. Whatever length, really.

I don't like FM. I'll get a XM receiver eventually.

As far as I know there is no way to integrate a PC with an aftermarket HU. You could probably run the output from a HU into the sound cards input or mic connector and have the music go through the PC. That's how an Ipod or XM reciever works, but you can't control a regular radio with the PC. EDIT: You might do something with a Universal Infrared Receiver/Transmitter.
http://store.mp3car.com/ProductDetai...Code=COM%2D018
I have a different type of reciver for my steering wheel controls and I use Girder program to map the buttons to the functions. The above device is also a transmitter. If your aftermarket HU has an IR receiver for a remote, then you might be able to get the PC to send a IR signal to the radio. It may be tricky, but might work.

If your hooked on local FM, you can get a radio tuner card. Most are PCI cards, but there may be a USB one as well. I think I remeber a really good one with AM as well, but I can't say for sure. Stuff like that you can search the forums.

eddielb · 10-18-2006, 01:43 AM

oh wow - awesome, ill try working on everything and see what kind of screen I end up using - if I end up deciding on relocating to somewhere other than the glove box, ill let you know, where are you putting your controls? Got a pic of your install?

JasonWW · 10-18-2006, 03:55 AM

My install is nothing special. I have a weak little 7" screen in the dash cavity. A/C controls are still in stock location. If I can find a good 10.4" screen to fill that location I'll probably put the controls in the center console. I'll make a little trim piece to fit around it to make it look nice when you open the lid.

narandomsortofw · 10-18-2006, 10:56 PM

So you were able to lengthen the cable? Put up some pics...you've only been talking about this project for like at least 7 months now.

JasonWW · 10-19-2006, 02:06 AM

So there IS someone who wants to see it. That's all I wanted to know.

With no screen right now I can only assume I'll still relocate the A/C controls. Most likely place will be the center console so I'll cut it all to that length. I figure if I end up putting it someplace else I can always shorten it later on.

Did you get the 49 strand 0.300" cable and a bicycle brake cable sheath big enough to allow 2 strands of the cable through? Those are the main parts, besides a new cable from GM Parts Direct. I wouldn't recommend cutting up the factory cable as you may not be able to get a certian part and you'd be stuck with no control over the temp.

I'll post up pics in a few days once my internet connection gets working again. We just had a big flood here and it's been out for 2 days now and I can't post pics from work.

narandomsortofw · 10-19-2006, 06:07 AM

Actually I sent mine to that company Push-Pull.com. They haven't come up with a way to do it yet...but I have faith.

JasonWW · 10-19-2006, 02:15 PM

I took a bunch of pics as I started putting it all together so I'll do a writeup real soon. I'm trying to do a lot of testing and experimenting so everything will work smoothly and last a long time and found a problem with the teflon coated cables. When passing through thr brake cable sheath and the sheath has a bend in it the cables rub against each other and jam up causing a lot of tension. No sweat tho, I burned the teflon off and then did some strength tests to make sure the cable wasn't compromised by the heat and it all looks good. It's still super strong. Not snagging at all when bent either. That problem is fixed.

Still, if your getting the cable and find some 49 strand (7x7) stainless steel 0.300 cable and it's NOT teflon coated, then go with that. Less potential for trouble, but probably no big deal.

I just need to index the cable ends under the dash so the knob will turn the right direction and not the opposite way. That's proving to be fairly hard as the cables do not stay seperated in the brake sheath (they get mixed up), but I'll figure it out.

turbocad6 · 10-19-2006, 03:46 PM

are you trying to run both cables through one sheath???

that can never work.....

you should just replace the factory cable with 2 cables, the factory cable really is 2 cables, but in one housing... you can't duplicate that, I would use 2 cables side by side... hope that helps

, if I'm off I'm sorry, I've only read bits & pieces here & there of your project...

JasonWW · 10-19-2006, 10:09 PM

Yes, both cables go through one sheath. Like I said, with the teflon gone and bare wire it works fine. No binding. I cut the stock cable sheath in half and added an extension, so to speak. I don't know why you would suggest it would never work. It does and works well. There really is no other way to do it as far as I can see. That factory cable setup is very specific in it's construction, you HAVE to use the end pieces for sure.

JasonWW · 10-19-2006, 10:13 PM

I did some testing by moving my 12" sub around in the car. It's a cube box so it's pretty easy to move around. I did a base reference level with what I had at the time which was a 40hz sine wave. I set my SPL meter on the dash and looped the track.

With the sub in the far back and firing up=111dB
on rear deck and firing to the rear=111 (surprised me)
on rear deck facing forward=109
on rear deck facing up=108 (kind of disappointing)
in the back seat area facing up=106
in the back seat area facing forward=106

I'm going to try an experiment and have the sub in the back seat and facing up and then get a rigid PVC tube about 12" and have it go up and over the back seat to the rear. All the output will exit to the back of the car in front on the storage well. If the output is real close to the highest levels I got above then I can build somthing like this:

Due the the longer path length the bass may play even lower than in the far rear which would be a bonus. I'm real curious how it will work out.

Aside from the higher output I didn't notice too much difference in the overall SQ. Firing into the seat backs you can feel them, but as far as SQ is concerned, the differences seem pretty small. I didn't listen to much music in that configuration.

5dB is pretty big to me, that's like what, more than the difference between one and two subs? I'm going to try an harness that extra output if at all possible.

Funny thing. When I was doing those tests the output stayed at 111 even when I rolled the windows down (temporarily), so maybe the car wasn't being pressurized very much at that low SPL. Then, when I hit the latch release, the hatch pops up a little bit and the SPL drops to 105. That surprised me the most.

turbocad6 · 10-19-2006, 11:59 PM

this is what I ment with the cables... these cables are extremely abrasive... you can actually use these cables as a saw in some cases on softer materials, we cut windshields out of cars with cable such as this... 2 of them rubbing against each other may be not so hot long term...

I'm proposing using 2 small sheaths adjacent to each other, actually that would be the equivelent of the factory setup... I think 2 can take the place of one, & match up with the factory ends... maybe at the very ends they will need to be shaved to like a d shape & even clamped togeather, but after the ends, it'll make no difference that it's 2 cables...

as far as the subs, corner loading them is corner loading them, that's why theres no real measurable difference between the 2 different positions, but both pointing at the rearmost corner... it don't care much what direction it's loaded from...

basically your last diagram should work, provided the "duct" that your forming doesn't affect the enclosure & act as a port... it won't affect the sound at all if you keep the total opening area larger than the surface area of the 2 subs & any ports, IE: if the subs/ports have a total surface area of 50 inches, & the duct has a surface area of more than 50 inches at it's shallowest opening & at it's exit opening, it won't affect the sound much, & your results should be aprox the same db as if you corner loaded it with the 2 other ways you tried, there may be a slight change in the delay, & this may affect your tuning, & there may be a bit of absorbtion from the baffle panel facing the subs themselves, but not a huge difference.... BUT if the opening from this duct happened to be LESS than the hypathetical 50 inches, it will then act like a port of sorts, or more acuratley it'll act like a labrynth design, which can be a bit unpredicatable......, but definatley have an effect...

turbocad6 · 10-20-2006, 12:04 AM

looking at your picture again, & considering your talking 2 15's... I think you'd have to make that baffle board/window a bit higher to keep the "ductwork" greater than the total surface area of the drivers..., it may be really difficult to keep the duct large enough for this....

JasonWW · 10-20-2006, 10:06 AM

Thanks for keeping me on my toes John.

On the cables, they don't seem abrasive at all. They are very smooth. The inner diameter of the new bigger brake cable sheath is enough to keep the 2 wires free and loose inside. Once the ends are assembled they will be under tension so they should not twist. Bind, maybe, but I don't think so. So far my tests have shown they won't bind once you remove the teflon. They will rub against each other so I know it won't last forever. Spring to Fall I keep it on full cold so I don't turn the knob then unless it's to defrost the windshield. In winter time I start the car on full hot to get it warmed up and then back it to the 1 o'clock position where it stays. Based on my usage I think it should last for several years, maybe 5 or more.

I wish I could test my design for say 2 years and then come back and tell everyone it works and THEN show them how I did it, but that doesn't seem right. I'm hoping it will last a long time and if not I'll source around for some twin bore cable sheath material. That would be the ideal solution, but I haven't found any.

On the subs, do you think the shape of the slot or tube would influence the sound? I figured a 12.5" or so OD tube would not restrict the output in any way, but if it might color the sound, then I may have to fab up a slot or square shaped design to test with my 12". With it and with the 15's, if I get them, I'll make sure the slot size is large enough so as not to act as a port.

I'm going to estimate that 2 15's are going to have a total surface area of 270 inches and the duct needs to have a surface area of more than 270 inches at it's shallowest opening and at it's exit opening, then it shouldn't affect the sound much, right? This doesn't sound quite right to me. Do the surface areas need to match up? If so then the inner size of the slot would need to be 38 wide by 7 tall. Figure an inch for panel thickness and you've got a slot that's 8" off the deck. That's about 1" higher than the back seat height and a bit taller than I was thinking.

I was thinking the cones on a 15" may be 13" in diameter
So pi x radius squared = 3.14 x 43 = 135 x 2 subs = 270 square inches
38 x 7 = 266 square inches

I was thinking displacement played a role. Is that not the case?

This design is giving me some ideas. It's so big I don't have much room for the amps or the PC, but it's mostly air so it's not too heavy. I was thinking, why not use that big duct and make a 4th order bandpass box. I could seal the end before the storage area and add a long port or 2 in there. It would be like no work at all to add that. I could clamp it on the end somehow and then remove it if I wanted. Just something to make you go, hmmm.