Need help on hooking up system

 

New member
Username: Mrtopher44

Maryland USA

Post Number: 2
Registered: Nov-04
Alright, first let me say I don't know too terribly much about car audio and how the volts and ohmage works and what not, I hope someone can help me out.Igot 4 planet audio VC10D subs in a custom built box.
Specs:
600w peak 300w continous
impedance 4 ohm

I got a planet audio big bang 1250.1 amp powering it.
Specs:
Max power (2 ohms) 1,000w x 1
Max power (1 ohm) 1,250w x 1
Rms power (4 ohms) 450w x 1
Rms power (2 ohms) 700 w x 1

What I would like to know is this, is this amp enough alone to power these subs. Right now I got it hooked up using a Rockford Fosgate farad cap, (20 volt surge)Idoes sound pretty loud, but it's not overwhelming which I wanted. I can still turn my bass boost up all the way, still clear, but it's just not what I thought it would be. I was thinking it would be just too much if I maxed the bass and the volume, but it's just not. Can someone please help me and break it down to me??
I've been to a couple different car audio stores and have been told numerous things, all trying to sell me something different or telling me this or that. I don't wanna go and ask another one because you don't know who to trust.
Thanks.
 

Help2
Unregistered guest
You might be experiencing some noise cancellation
depending on how the subs are facing, in which
case you'd have to get a different box, or
a different set-up altogether.
The amp you have is rated at 1250 wRMS @ 1 ohm
which is perfect for the subs you mentioned.

Its difficult to have 4 subs in a car audio
install with no cancellation.

What kind of vehicle are they in, and how do they face?


 

New member
Username: Mrtopher44

Maryland USA

Post Number: 4
Registered: Nov-04
I don't have a spare tire and the box is built to fit perfectly in that space. The subs are facing down (backwards, at a slant.) It's kinda like this, a box, draw a line down the middle, that's the lowest point, at then it's slopes upward on each side. And there are 2 subs on each side. That's how their set up. You think that's good? It's in a 2002 honda accord.
 

New member
Username: Mrtopher44

Maryland USA

Post Number: 5
Registered: Nov-04
It's in a 2002 honda accord. The box is where the spare tire would be, custom fit into that spot. Imagine a box, draw a line down the middle, that's the lowest point, then it slopes upward, with 2 subs on each upward slope, make sense? That's how it sits in my trunk..
 

Silver Member
Username: Carguy

Post Number: 537
Registered: Nov-04
Hey Christopher, there's more to it than just subs and amps. A good box for example could make a normal sub sound much better. A bad design can kill a good sub.
Also you said you have 4 subs. You don't need that many to get a thundering bass.
Let's say each of your subs have 40oz magnets rated 300w. If you crank up the volume, they may sound loud, but it'll lack the heavy thunder. That's cause the magnets are too weak/small. There's always a reason why some subs are priced very low while others are 2x - 3x higher.
If you want an example, go visit a car shop and test out 2 subs by same manufacturer with 2 different magnet mass. One will pound your chest, while the other one will just pound your ears.
One other thing to keep in mind is the amp. Some have SN ratio over 100db, while others are below 80db. They play a significant role in bass volume.
 

New member
Username: Mrtopher44

Maryland USA

Post Number: 6
Registered: Nov-04
Here's what I want. Heartpounding bass, that can't be turned up to max without it being just too much inside the car. Basically loud as hell. I thought this would do it, but it's not what I thought it would be.
From what you said Isaac, what I got should theoretically be what I want, but it's not. Do you think if there were two amps, same kind I already got, just another would do the trick, or is it what Help2 said, it could be the box? And cancellation?
 

Silver Member
Username: Carguy

Post Number: 542
Registered: Nov-04
Hey Christopher, if you want to know exactly, you'll need to post your amp's spec, speaker's spec and a pic of your box.
Even with my weak Jensen amp (350W), it was pounding my 18" sub pretty good.
When you say heart pounding bass, do you mean windows/mirrors/wipers all shaking? For that to happen, you'll need a combination of box/speaker/amp.
 

New member
Username: Mrtopher44

Maryland USA

Post Number: 7
Registered: Nov-04
The specs, are on my first post. Is that enough or you need more in depth specs? As far as pounding wise, I want the damn rear view mirror to fall off. As far as a pic of the box, I'll try getting that, it might take me some time. I'm currently deployed in Iraq, and I'd have to have someone take the pic for me and send it to me through e-mail. For now, I'm trying to figure out what's going on with my system, so when I get back I got a good idea what I might need to do, ya know?
 

Silver Member
Username: Carguy

Post Number: 550
Registered: Nov-04
Hey Christopher, what I was looking for was the SN ratio number for the amp and subs along with the magnet weight.
Who designed the box for the subs? Was it custom made? Was it done according to the manufacturer's spec? Is the box ported? Do you have HO alternator and adaquate power wires?
What is your power wire's fuse size? What are the total fuse size in your amp?
Once you have all of the answers to the questions, then you will be able to determine some kind of solution.
 

New member
Username: Mrtopher44

Maryland USA

Post Number: 8
Registered: Nov-04
You can just call me chris. Here's what I got.
AMP- 102db signal to noise ratio.
SUBS- 91db signal to noise ratio.(1watt/1meter)
2 1/2 inch voice coil.(aluminum) Each weigh 80 oz.
BOX- was custom made, don't know total size of it. No ports.
What is HO alternator? Wires I think are 4 gauge, possibley 2, probably 4. 60W fuse for wires, there are 4 25w fuses on the amp.
Again it is also hooked up to a cap, 20v, don't know if that helps or not though.
That's what I know, does it all make sense to me? Not really....
 

Silver Member
Username: Carguy

Post Number: 554
Registered: Nov-04
Hey Chris, that answers some of the questions. Your amp sounds like it's alright, same with the subs. However, the magnets are under the weak/small side. I've had subs with 80oz magnets before. They don't pound as hard as 180oz or 320oz. Sure they will sound loud and deliver low bass, but not the kind that beats your chest and make your hair stand up.
When you get back from Iraq, try taking one or 2 of your subs in a different box. That might be the cheapest solution. If not, I'd try a sub that's 15" or 18" with 320oz or heavier. That will surely pound the crap out of your car.
If you currently have 4 10" subs, then you should be able to handle 2 15" subs.
Remember, the box design is VERY important. It has to be made according to the speaker manufacturer's spec.
As for your configuration, it looks like you don't have enough power to drive the amp to the max. If your amp truely delivers 700W rms, then your current setting won't be able to supply the juice.
Your amp has 4 25A fuses meaning you'll need to provide 100A of current. That's more power than your stock alternator can handle.
You mentioned 60W fuse for the wire, I think you meant 60A right? That needs to be changed to 100A to match your amp.
The capacitor you have, it's probably 1F right? Not big enough. You'll need 1.5 or 2F, but you can change that last.
I hope that helps you.

 

New member
Username: Mrtopher44

Maryland USA

Post Number: 9
Registered: Nov-04
I got a couple more questions. So, your saying, I can just switch the 60A with a 100A no problem? As is with cable and all? The current set up can handle it?

What if I had 2 different non ported speaker boxes, just regular one's from best buy, might that help? And put one on one side of the trunk and one on the other. As far as the current box, like I said I don't know what the actual size is, but the guy that made it said it might be a little small and mentioned something about filling it with pillow stuffing. Does this make sense?

The cap is a 1F, so if I put 2 1F's that'll help? Also, your saying the current stock alternator isn't able to put out enough power, what can I do to fix it?

Lastly, in other words as far as the subs I do have, 80 oz, your saying they're good, but not that great? And your saying the heavier or more oz's they are the harder they'll hit?
 

Silver Member
Username: Solacedagony

New Jersey US

Post Number: 105
Registered: Oct-04
Should be able to swap the 60A fuse with a 100A fuse of the same type with no problem.

The pillow stuffing would be called polyfill. It basically makes the subs think that the box they're in is bigger than it really is.

If you want heart pounding bass, a sealed enclosure isn't gonna get you any closer. Ported all the way.

Capacitors are the last thing to worry about really. Like Isaac said, you probably will need to replace your alternator with a High Output(HO) one.

Also, 10" subs don't carry as much of the boom as bigger subs like 15"s do. More sound and lower frequencies out of bigger subs. So Isaac is generally correct on the magnet weight.
 

Silver Member
Username: Carguy

Post Number: 555
Registered: Nov-04
Hey Chris, before you go out and buy more boxes, you might want to research the speaker manufacturer's requirments. You have to follow their instruction to get max sound.
I doubt you will get much from your current speakers.
If you have the time, go check out the 15" or 18" subs with heavy magnets and "large" voice coils. I can almost guarantee they will make significant difference. Even with 1 18" sub, my car mirrors shake and rattle, and that's with the volume not even half way.
As for your alternator, check out 4alterstart.com. They should have the 170A - 200A alternators you need for your car. I bought mine from them.
One more thing, some of the boxes that are well designed, cost almost as much as the sub itself. So do stay away from cheap ones.
Here's one of the quotes from speaker experts:
"In order to get more bass you either have to go to a larger cone or you have to move the cone farther in and out. This is because the radiation impedance of air is very low at low frequencies"
 

Sucubus
Unregistered guest
Couple things...

If the 60amp fuse isnt popping, why change it?

Magnet weight doesnt necessarily mean its going to
be louder, or more powerful.
A larger magnet allows for more power handling
yes, but if the suspension is pushed to its
limits, who cares how big the magnet is.
a perfect example is Audiobahn...
they have huge magnets, but they can only take
half of the rated RMS before bottoming out anyhow.
not only that, magnet weight doesnt necessarily
mean strength.
there are several kinds of magnets, which
have different force to weight ratios.
 

Silver Member
Username: Carguy

Post Number: 578
Registered: Nov-04
Hey Sucubus, that may be true, but in most cases the magnet's weight/strength and the size of voice coil play a very significant role when it comes to power. I won't go into how a speaker operates, I'm sure you know how to use google.
Using extreme examples to discredit the benefits of having strong magnets won't help anyone. You can't tell me that an 18" sub with 320oz magnet and 3" VC, will perform less than a 18" sub with 100oz magnet? Sure there are different types, but you can't compare oranges to apples.
If you want proof, take 2 identical subs with same type of magnet, same size voice coil, from same manufacturer, but one with heavier/stronger magnet. Now apply same power. You can't honestly tell me the magnet doesn't play a role?
On with the important topic:
Chris, 80oz is not great for a sub. It is ok. Visit a car audio shop and let your ears be the judge.
One more thing for Sucubus, if you can find a sub with small magnet/voic coil delivering more thump and power than a larger one, I'd like to know. Again, don't compare appples and oranges, like taking the best sub from one manufacturer and the worst from another... :-)
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