RotorMotorDriver

iTrader: (1)

And from the back....BTW, if you look, the mis-measurment isint as bad as it loks in the first pic, its acutally only like an inch or something

RotorMotorDriver

iTrader: (1)

Heres the box done, its obviously not in the car , but just for fun (and visual aid) we spray painted where the speakers will go. The spray paint give you a little bit of "scale" for your imagination too work with on the pic...

RotorMotorDriver

iTrader: (1)

Here it is in the car from the back, most of the space between the subs will be taken up by the amp...im not sure when ill have the whole thig done, im hoping by Sun night. ill have to hold off on carpet, and the equipment until i get more money (no job), but at least it will be built and ready for the stuff once i can afford it. Im also still considering a location for my capacitor, ill keep you posted...

RotorMotorDriver

iTrader: (1)

Oh, and if your wondering, the back of the box is taller than the metal so when its put back together, it will all sit flat, due to the spare tire height. after the insulation, rubber, and carpet . So when you look at the back, in theroy it will all be level

~T.J.

Max7

I have no doubt of your knowledge, or your experience or certification.
I all ask is some proof, of this 2 makes 3 sound level.
I've been doing car audio since the mid 80's and never once, from install shops, dealers, or manufactures, (cept maybe pyramid, haha) that if you have 2 speakers it will 3 times as loud as 1.
just some friendly chit chat

FuLLsMoKe

When you run 2 DVC on one amp, you can wire the configuration for both speakers and the amp to run at 2 or 4 ohm stable. But with my SVC 12", I am running full power at 4 ohm stable. I've never heard of 2 subs being as loud as 3... Plus the space deal--I need cargo space since I need to carry women around (they squeze in the hatch area)

So... not trying to **** anyone off, but I'm not gonna go with the 2 12" deal... I don't have the space and I don't plan to enter any audio competitions... I like the way my single 12" sonds and I'm happy with that.

V8kilr

I totally explained why it does,here it is again

1 12" speaker on an 800 watt amp is only using 400 watt @ 4 ohm

2 12" speakers on an 800 watt amp bridged in parrallel is using the whole 800 watt

besides i didnt say "2 makes 3 sound level" i said it will get "three times as loud",so in ther words you will not get 3 times the spl,thats "sound pressure level" for those who do not know,but you will get more then twice the amount of bass.

even when you hook up 4 subs theres no garauntee your gonna get 4 times the spl.

MIKE-P-28

iTrader: (1)

I think the best way to say this is, a 6db gain is twice as loud. But when you keep adding woofers unless you double the power each time, there will little/if any gain...

Oh and the impedance of a woofer, or any speaker for that matter, is never always 4 ohms, 8 ohms whatever.

At resonace the speaker can be as high as 1500 ohms. Or at 20hz it could be a 1/2 ohm... Impedance is indirectly proportional to frequency....

If you want proof hold a 10 inch sub in your hand, and hook a DVM to it, move the cone, it wont stay in the 4 ohm range.

Another neat thing is take 2 subs and wire them in parallel, w/o hooking the wires to an amp. Move one and the other one will move too. Thats because the sub woofer you move creates a voltage thorugh inductance...

Max7

Also it should be noted, that not all amps will double thier power when halfing thier ohm load.
Alot of todays mono amps will push thier 800 into a single speaker.
so if you have a single 4 ohm speaker. you get the 800@4ohm, you can also use 2 8 ohm speakers, and still have a single 4 ohm load, and still have 800@4ohm.
even though you double the cone area, they are only getting half the watts.
then there are dual voice coils, and even 2 ohm and 6 ohm coils, so much fun!
just letting the newbies fully understand this, there are so many combos, you can't just add another speaker and always get things louder.
then there are the problems when mounting speakers that can effect thier performance in relatation to each other

V8kilr

could you please find me a mono amp that pushes its max @ 4 ohm.good luck

Max7

weather its max is at 4ohm or 1/2ohm, its still the same, in that what speaker combinations you use may not yield more power from the amp.
And I remember a day when a bridged 8ohm load was the most an amp could take.
The first 1ohm load amp I recall was the Orion HC100 (or sumthin like that)

MIKE-P-28

iTrader: (1)

You guys also forgot to mention, regulated power supplies and non regulated power supplies. Amps that produce more power with voltage... And a mono amp is really a 1ch amp. Well as far as the ones I see. They sum the input stage and the output stage and power supply dont look any different than a regular amp.

HCCA 50 was the first amp I remember that would take a 1 ohm mono. And man at 1 ohm, you could cook on one They got hotter than the fires of hell!

mar3

iTrader: (8)

Whether you realize it or not, you just proved V8kilr's point because, silly rabbit, you don't get half the watts, you're getting ALL the watts but with TWICE the cone surface area. And, in the end, it's not the total wattage that makes the most difference (even though that is significant..) but how many sq.inches of woofer you got to push air that makes sound pressure, aka. "spl".



For pete's sake, is that wood knots I see?? THAT is where the sap comes from, amigo!! I hope temps in your area never reach 102 degrees Fahrenheit or you are going to sorely regret not having used MDF...

Felix Wankel

I don't like having subs facing up or forward. Mine always face backward, and as far back as possible. Sometimes facing them up makes it sound better outside than inside.

mar3

iTrader: (8)

The system I'm attempting next will have the 4 12" DVC subs facing each-other. 4 across facing forward meant I lost the center "aisle" in the hatch and it's not worth it anymore. I saw a truck that did this with just 200 watts and 4 15" subs and it flat out blurred your vision...

nipplebandit45

I just got dne re-making my sub boxes. I like the zbox so I triedto copy the style a bit. Mainly the locatoin. Couldnt find any MDF so I went with 3/4" Particle Board. It's never done me wrong in the past....

Here is my question, what happens when you dont make the box the reccomende size? I.E.. My subs areKenWood 8" tornadoes. the specs call for a box with 1.5 cubic feet. when I had the ubs in boxes not only did I not have much Cago room, but theysounde like Poo-Poo. Now the new boxes are .67 cu and the subs sound a LOT louder and better. Origionally my subs were firing straight up about 6 inchs in from the back window latch. Now they are where thezbox ges, but they stick into my hatch area about 5".

Why sch a increase of sound and quality? is it the new angle or the boxs?

My amp hasnt changed, it is a "Power Acoustic" gothic series 300w amp. course it only has a single 30amp fuse and I doubt that it would ht even close to 30 watts.

Mike

Felix Wankel

Gonna do it isobaric? Thats some cool ****. I had 4 JBL DVC 15's in my 4 door Chevette (!) running 2 ohm mono per pair on a little Punch 60 per pair. They were facing each other in an isobaric box that was as big as the back of the car.

16 year olds will do some crazy ****

mar3

iTrader: (8)

You just reduce the efficiency of the woofer unless you go way too big or way too small. In your case, it sounds tighter because you've "beefed up" your acoustic spring that the woofer works with in your box. I'm willing to bet you lost some of your bottom bass capabilities because of the smaller box size, though...


--->Felix, believe it or not, the 4 subs are going to be all separate with their own individual airspaces. I got some 1 1/2" thick industrial PVC tubing to mount each speaker in and some ROUNDED laminar matrix wood composite ( used as bucking dyes to cut cardboard boxes on...) that will be used to create the actual "box". It's all going to be very organic in nature once done. Like RMD, I'll start posting once I get started...first, I've got to get this damn garage, compressor and workbenches done so I can unpack all of my references and tools!!

Max7

ok, silly Rabbit
I will explain it again, if you have 800watts going to 1 speaker, or 800 watts going to 2 speakers, then thats 400 each. 400 watts to a single speaker is not as loud as one receiving 800watts, which is what I was explaining. Yes the cone area is doubled, but the excursion will be less. and its the excursion of the surface area that creates SPL, not just the amount of surface area.

Felix Wankel

PVC is cool, I have some 6.5'' in the factory location in the back of my TII, in PVC tubing. The open area the stock 4'' go is crappy.

V8kilr

your still not getting it since 97 its been a standard for amps to be able to operate @ 2ohms.

the power increase will not always double as the ohms are lowered,but it will increase,its OHMS LAW

tell ya what you pick any three amps of your choice and we will check to see if in fact the power does increase @ 2ohms over 4 ohms.

here are three i picked for an example
high end to low end

Rockford Fosgate Power 250.2
62 W X 2 @ 4 Ohms RMS
125 W X 2 @ 2 Ohms RMS

Boss RT-335 500 Watt
125w x 2 @ 4 ohms MAX
250w x 2 @ 2 ohms MAX

Pyramid Model = PB450PX 500 Watt
2 x 125 @ 4 ohms MAX
2 x 250 @ 2 ohms MAX

Go figure????

Felix Wankel

Damn Boss is still in business? Haha!

V8kilr

boss has actually won quite a few iasca competitions.
i remeber one with their suburban,and one ill never forget the one with their ford armored truck.

RotorMotorDriver

iTrader: (1)

Ok guys...Shes as close to done as shes gonna get for now . I finished the box today, cut the lid for the amp box and everything. I think im gonna hold off on cutting the circles out until after i have the subs, just for fitting purposes, ill cut small and get bigger , that way i dont cut them too big accidently. Anyway, I laid all the interior pieces back in, except the plastics, and put down a piece of carpet. The carpet is definatly NOT what im gonna keep in there, its just all i had at the time. I think it doesnt look that bad in there, i need some BRUTALLY HONEST opinions though...what do you guys think, just as far as looks and idea goes?

~T.J.

RotorMotorDriver

iTrader: (1)

Ok, last pic for now. This is a close up of the amp box with the carpet cut around it, pretty exciting eh? Anyway, my finishing steps are: 1. line the inside of the amp box with speaker box carpet 2. route out an edge for the plexi-glass lid to sit down in 3. install the cooling fan for the amp compartment 4. install the cruise control computer in its new home (side of speaker box) 5. re-carpet the interior with the right carpet (havent yet decided on what kind yet) 5. install the stereo components. And thats that!

~T.J.