Sub & Amp Question

[VRDaniel]

I'm totally new to car audio so I'm sorry if I come across completely stupid.

I have:

2X - 15" Subwoofer
Max Power 1600 Watts
RMS Power 800 Watts
Impedance: 4 OHM

AND

1X - 4800 watt amp
Output Power (Max): 4800 Watts (120W x4 load 4 ohms)
Output Power (RMS): 480 Watts (120W x4 load 4 ohms)
Output Power Bridged (Max): 4800 Watts (2400W x2 load 4 ohms)

and I'm curious as to how I should run them.

I'm not even sure which should have the larger wattage e.g. will a sub with larger wattage fry my amps channel or will the amp with too much wattage fry the sub.

Thanks in advance, Daniel

[Stretchomatic]

best idea for starters is more details on the gear...like what sort of watts RMS they are running and the brand and model...

the best way to run 2 subs is go from positive on amp to positive on sub1 then a seperate wire from sub1 negative to sub2 positive then sub2 negative to amp negative...i think its called series lol...i suck with the names...

generally with the powers it doesnt matter depending how they are tuned...if u turn the sensitivity and voltage up full high then something will probly die no matter what...whether it be from over powering or power clipping the subs or overheating the amp...

but yeah for starters more info on the gear.

[VRDaniel]

ok, so the installation you explained is using one channel of the amp for both subs?

Would it be just as acceptable to use 2 channels for 2 subs?

e.g. Chan 1 negative and positive to Sub 1 negative and positive respectively?

[Shaneus]

Hello Daniel,

The whole purpose of questions is to gain knowledge so you don't ever feel dumb asking a question. Even if a purpose laughs at you there was a stage ion there life they didn't no the answer aswell.

anyway

1X - 4800 watt amp
Output Power (Max): 4800 Watts (120W x4 load 4 ohms)
Output Power (RMS): 480 Watts (120W x4 load 4 ohms)
Output Power Bridged (Max): 4800 Watts (2400W x2 load 4 ohms)

This doesn't look right to me. Could you please double check this for more accurate information. Also brands and model numbers will help like Stretchomatic said.

[Joe Peeps]

the best way to run 2 subs is go from positive on amp to positive on sub1 then a seperate wire from sub1 negative to sub2 positive then sub2 negative to amp negative...i think its called series lol...i suck with the names...

Your right it is series wiring, but no it isnt the best way to wire subs That will depend on coil impedance and the capabilities of the amp. However, generally you dont want to wire seperate woofers in series due to the potential for back emf (which may/may not effect your systems sound quality but is best avoided)

As mentioned, some model info and those that can will show you how to best wire your subs, but your above post is likely the best - that is, one sub off a channel, and the other sub off a seperate channel.

EDIT:
As for your other question, it doesnt matter if your amp/sub are slightly mismatched, if you set your gains right (ie so there is no distortion) then you want have a problem either way. Nothing will get fried if you dont ask more then your system can handle

[Tasmaniak]

VRDaniel I know that you will take my advice with a grain of salt but unfortunatly even if you were ABLE to bridge all four channels together, you would still only have half of the power required to run one subwoofer.

Typically when when matching subs to amps you want your RMS to be about the same power rating as the speakers; give or take 10%

In all reality you need to be buying a bigger amplifier and using that four channel to run the car speakers.

You are in serious danger of underpowering the subs. Now, without having much knowledge of car audio, your not going to know when dangerous underpowering is happening.

An amp that is much smaller then the speaker can damage/destroy both the amplifier and the speakers.

Sorry to burst the bubble but you are at risk of doing a lot of damage. Save your pennies and but an amp that can push 1600wrms at 2ohm. Not many amps can do that so you may need to purchase two 800wrms @ 4ohm amps.

Cheapest that I know of is the Jaycar 1500wrms @ 1ohm at $699 each and your gonna need two of them.

Your other option is to sell of the two 15s and replace them with some of lower power.

[daron]

buy 1 mono block amp and load up both subz on one channel only is best way to run subz
if you cant afford new amp right now bridge 2 channels and put from + of amp to + of both subz and - of amp to - of both subz
make sure box is sealed tight and chambered but both sides must be same size
feel free to ask any q's noone will bag ya we all learn daily

[Tasmaniak]

If you can't afford a new amp then don't use these subs as you will be severely underpowering the subs and will eventually be left NO amp and NO subs.

[Joe Peeps]

bah! Dont listen to 12volt with his reason and logic and utmost practicality!!!!

I maintain that it can be done, and am a firm subscriber to the theory that there is no such thing as underpowering. It is more a case of asking what a system cannot deliver.

if you cant afford a new amp, ask yourself these questions:
can live with little bass and people asking why your two fifteens cant be heard?
can you resist the urge to crank your stezz and play 33hz tones when a hot chick pulls up next to you?
do you know what a clipped signal is?
Can you tell when a woofer is distorting?

If the answer is yes, no worries. If no, listen to . and hold off and buy a new amp: even a 1000rms mono will do the job, or dare i say it even an 800rms model if thats all you can afford.

[VRDaniel]

Ok thanks for all your posts guys, and I can see where i've gone wrong. (I think)

The subs need 800 watt rms power when the amp can only give 120x4 rms power meaning if all channels are bridged i still only have 480 watt rms where I need close to 800.

In answer to your questions Joe Peeps "No" is my answer to all of them. Especially question 2. Sooo i'll have to invest in a new much more powerful amp.

Thanks for all your help guys.

[VRDaniel]

buy 1 mono block amp and load up both subz on one channel only is best way to run subz
if you cant afford new amp right now bridge 2 channels and put from + of amp to + of both subz and - of amp to - of both subz
make sure box is sealed tight and chambered but both sides must be same size
feel free to ask any q's noone will bag ya we all learn daily

I'll use this solution until I can save for an amp. Thanks for putting it in simple terms as well ... lol

[Joe Peeps]

No dont do that!!!!

This will present the amp with a 2 ohm load as that is parallel wiring, which is fine if your amp can handle 2 ohms bridged, but any amp that lists its specs in max power is unlikely to be thus capable. This will likely end up in a cooked amp!

If you bridge two channels, just run a single woofer! This is what i would do in your position: bridge 3+4 to run a SINGLE woofer. I hope this hasnt confused you more, but trust me, you do not wanna run two subs, wired down to two ohms, from a bridged four channel. Any questions feel free to ask. Daron is usually pretty good - he must have been tired when he wrote that

[VRDaniel]

No dont do that!!!!

This will present the amp with a 2 ohm load as that is parallel wiring, which is fine if your amp can handle 2 ohms bridged, but any amp that lists its specs in max power is unlikely to be thus capable. This will likely end up in a cooked amp!

If you bridge two channels, just run a single woofer! This is what i would do in your position: bridge 3+4 to run a SINGLE woofer. I hope this hasnt confused you more, but trust me, you do not wanna run two subs, wired down to two ohms, from a bridged four channel. Any questions feel free to ask. Daron is usually pretty good - he must have been tired when he wrote that

Phew, lucky I didn't do anything yet.

Would something like this be appropriate to run one sub, properly? or two?

[Joe Peeps]

Hmm. It could work for both, you would just have to be careful not to push to hard. Whats the exact model subs, and your budget for an amp and perhaps some suggestions can be made (that is if you havent bought anything yet ) but id imagine the jaycar monos or second hand look like your price bracket. Remember to always look for RMS figures with speakers and amps, max power figures are next to useless

[Tasmaniak]

that is too small still. You need 800wrms @ 4ohm to power a single sub. Or 1600wrms @ 2ohm to power both subs.

[VRDaniel]

1600wrms at 2ohms ill look around and see what I can find....

Wow cheap?