wiring gauge to amplifier

Hi Guys,

This is my 1st  post, so here goes. I just recently upgraded my amp (Sony 600w) to a MTX thunder TC 4004 ,400w RMS.

Running rear channel bridged on one 12 '' MTX 300W RMS sub.

Exisiting power and ground wire gauge is 10 gauge. 

4 gauge wire is recommended. Question : Will I get better deeper bass by switching to the 4 gauge.

Thanks. 

dwarren, I have a question about your reply..not trying to start an argument but if what you stated is true, I don't really understand why.

Now the poster did not mention the ohms value of the sub so we don't know the actual power output .... I will assume the max. power,.which is 400w rms. for the sake of this topic. The current demand would call for greater then a 10ga, I would say to be safe at least an 8ga. for a 15 foot run..Iasca would call for at least a 4ga. which is what I would use as well.

So..by using the proper gauge most of the voltage drop that can occur though the smaller ga. wire will be eliminated. There is really not enough info given to predict what the poster is asking...to quote "Will I get better deeper bass by switching to the 4 gauge", however it is a possiblity. Well technically I don't think "deeper" is the right term..that has to do with tuned frequency..but the bass might be louder and cleaner...regardless, this is not really where I have issue.

The following statement..."Using a power wire that is too small for current draw demands will put excessive strain on electrical components" is where you lose me.

If the wire ga. is too small...the result is voltage drop..so..how can having less voltage going to the amp cause a strain on any eletrical components? I can see this putting a "strain" on the power wire and creating heat..not the best thing ,but I would tend to think the only noticible "side effect" if any would be poor or "less then optimized" amplifier performance .

To add to this..although I can't speak for everyone..common sense should dictate that if an amplifier is not getting enough voltage to the point of noticing it by ear, that it would be dealt with long before actual damage was caused by it...if it is possible. So in a nutshell I am asking if it is possible for an amp to be damaged from voltage drop causing a strain on the components....how is this possible?

Thanks

Thank you both for replying to my post. I did forget to mention that my sub is rated @ 4 ohms.

Custom Audio you do pose a very interesting question and I am interested in the outcome of your query.

I was hoping that the 4 gauge upgrade will improve the quality of the bass.

Cheers.

It causes excessive strain on the components because that extra heat in the power wire also results in the components of the power stage of your amplifier.  Basic ohms law  and power equations says that if less voltage is reaching the amplifier it will draw more current to produce the same power, (Watts=Volts*Amps) The performance of all solid state circuitry particularly (but all circuitry to some degree) is dependent upon temperature.  Just look at the tech sheet for a transistor, it has graphs of how certain characteristics of that part are affected by temperature.  More importantly the base junction or gate junction can be destroyed by heat and the part fails.  This is why amplifiers have heat sinks on them.  It helps disipate the heat of the transistors and protects them from thermal breakdown.

I hope this makes sense.  I would be happy to elaborate more if it is needed.

SoundAudio, thanks for responding..this is becoming interesting.

I undertand using ohms law...if we assume the power output will be the same regardless of voltage...and we lower the voltage in the equasion  I = P / E that it will show an increase in current.

What I can't understand is why the power does not decrease if the voltage is lower. I know the wire gets hot if it is too small because of friction..too many electrons are being called upon by the amp..they can't all fit at once during peak demands....ouch..hot wire...voltage drop as well.

Now the amplifier will draw current..as much has it needs to operate..but it requires a certain amount of voltage...if it loses V however....lets say a weak battery....current available will decrease..power will decrease..heat will decrease. realize I am not coming from an engineering standpoint...just common sense.

Now how can the amp tell the difference if the drop is from a wire that is too small...or a dying battery? It should only notice a decrease in voltage..wouldn't you think?

Have you or anyone actually experieced or seen an amp run hot ONLY because of a small wire?

I know in my experience I have seen heat problems due to running ohms loads too low...or inadequite ventilation.

Now if this is true..and I can be convinced of it, understand that I always use wire that is larger then required..overkill , and if I see a system with the wrong wire ga. come in with problems I won't touch anything until the right wire ga. is installed.

But the problems I expect from the wire being too small is voltage drop....causing the amp to shut off at peak demands and limting power..which limits output..which limits SPL..so on....but heat from too low a voltage??? I would be much quicker to believe with everything I have learned about amplifiers that too much voltage will cause a "strain" on the amps internals..not too little.

Can ya see my point? If I am wrong please help me to understand. Thanks.

I did make the assumption that the power would stay the same which is not typically the case, you normally get more output at 14 volts then 12 volts.  The amplifier will still demand more current if the voltage is lower.  The increased heat from the greater current draw reduces the robustness of the circuit, and in turn reduces its life span. 

Sorry to pick your brain..and thanks for taking the time.

So..will the type of power supply of the particular amp make a difference with this subject?

Should I conclue that lower voltage can cause more current draw (I just can't argue with ohms.law..it is a law)..which can cause more heat...In other works can we expect every system that has smaller wires to the amp to run hotter? If I share this info..which is new to me..I want to be 100% sure I can back it up. I have searched the internet for a good hour and can not find any useful info on this subject at all. Why the secrecy?

No.  1/0 gauge is much larger and more capable than 4 ga.  The amplifier is recommending minimum 4 ga.

(K.I.S.S.)