HELP Audio troubles

[RevvedUpGaming]

So I was wondering if on a amplifier for a car if you could turn down the watts it was delivering to the sub as I am thinking about buying a 730 watt amp but my sub only takes 600 RMS

 

Please help

 

[ARikozuM]

I may be wrong on this (and I'd wait on other car guys) but your amplifier will only deliver 600 to the sub.

[SpaceMonkey]

What model amp are you getting? Some amps have a small screw you can turn to adjust how much power is going to the speaker/sub. It technically isn't "turning down" the wattage the amp can produce, but it can help you avoid over driving the sub.

[JokerProduction]

This is a little bit of a complex question and kind of has multiple ways of accomplishing this.

 

1.  As per the above poster (95%+ of amps will have and adjustment called gain)  This will adjust how much the low voltage signal coming from the deck actually gets amplified and then sent to the speakers.  You just don't turn this up all the way.  Of course there is only so much range but going from 700W to 600W is almost certainly not a problem. BUT see#2 below as that is VERY important.

 

2.  Amps are rated to put out so many watts at a certain impedance and have a level of impedance that they are stable down to(usually 4,2, and more expesive ones are 1, 0.5Ohm)  So you have to look at the rating on the amp which will probably say 710w@4ohm or 710@2ohm.  Next a subs voice coil has some impedance.(and some subs have multiple voice coils and will say dual or quad 2 or 4 ohms)  you have to know this number to know how much power you amp is actually gonna supply to your sub. (you can take a multimeter and measure resistance to find out if you cant find it on the sub specs) 

 

Heres a couple scenarios to try and help you understand.(this is all assuming your just starting with your gain at100% which is stupid but for simplicity sake were going with that.

 

-Say you amp is 710W@2ohm but your sub is 4ohm the amp will actually only ever provide 355W to that sub. 

-say your amp is only rated to 710W@4ohm but your sub is 2ohm that sub is actually going to try and pull 1420W which the amp cant handle and will over heat as well as the voice coil will heat up and there is the possibility that you will rip the cone from over excursion.

 

3.  The next way is not always an option as it depends on the sub your using.  If you have multiple voice coils (or multiple subs) you can wire them in either parallel or series to get different impedances. 

 

IE.

- dual 2ohm subs can be wired to be either a 1 or 4ohm load. 

-dual 4ohm can be wired to be either a 2 or 8 ohm load

 

and finally just because an amp puts out 710W its only doing this at 100% volume and gain. so unless your listening to you music maxed out all the time there is no issue using that amp as long as the electrical specs match up as per my points above. 

 

One final note as well is that there are 2 different power ratings RMS and peak or max.  you want to make sure that you are comparing the same values. A lot of cheaper brands will use peak power because its a bigger number and markets better but RMS is really the effective power that's actually being used and should be the number you always want to use.

 

I'm a electrical engineer that got into this profession because of car audio and it is something that is actually a lot more complex than most people realize and probably the reason there are so many fried amps and cooked subs out there...

 

Post the part numbers of the sub & amp and Ill gladly tell you best setup for it or if its even a feasible setup.

 

 

 

[bob345]

On 7/27/2016 at 9:33 PM, wjm22400 said:

So I was wondering if on a amplifier for a car if you could turn down the watts it was delivering to the sub as I am thinking about buying a 730 watt amp but my sub only takes 600 RMS

 

Please help

 

simple answer is yes, all car audio amps have a gain setting. This changes the sensitivity of the amps input which can limit the amount of output the amp provides. The main thing you want to worry about is making sure the amp is not clipping or "distorting" at high volume. Clipping is the major killer of any kind of audio driver. Also, is 730 watts the max listed wattage or is it the rms?

[.spider.]

9 hours ago, bob345 said:

Clipping is the major killer of any kind of audio driver. 

It is not.

It's just the higher power and additional power in higher frequencies if there is also a tweeter connected to the amplifier.

[Huntsman]

Dont' crank the volume past half and you'll be fine. Seriously 600W sub for a car...

[straight_stewie]

On 7/27/2016 at 11:33 PM, wjm22400 said:

So I was wondering if on a amplifier for a car if you could turn down the watts it was delivering to the sub as I am thinking about buying a 730 watt amp but my sub only takes 600 RMS

Firstly, what kind of amp is it? It's extremely likely that the "730" watts (that's a mighty weird number) they are advertising is just peak wattage, your RMS wattage will likely be much lower.

In either case, wattage is defined as any one of the following three: P=VxI; P=RxI² ; P=V² / R. P = Power (watts), V = Voltage, I = Amperage, R = Resistance (Impedance). So, What is the impedance of the speaker (ohm rating), and how many watts does the amp actually put out at that impedance? If you know the speakers impedance, it's very easy to calculate how much power is actually being used to drive the speaker.

Beyond that, use your ears. Put the head unit volume at the highest volume you will play the radio at, make sure the amplifier gain is all the way down. Start turning the gain up until you hear distortion. Turn the gain back down a little. You should preset your filters before doing this. Most likely, if there isn't any distortion and the drivers aren't overexcursing, then you'll be fine.