WHY IS MY AMP SO HOTT?!?!?!

 

Bronze Member
Username: Audiobahn_man

Freakmont, MI

Post Number: 49
Registered: Aug-04
Im running 2 audiobahn 600 rms subs in a ported enclosure, sony 1200w amp at 2 0hmx 2, and the thing gets super hot after about 5 min... i think it might be because i have 4 gage running to it, and only 8 for the ground..and sugestions? yes i plan on getting new sh@t once pay day comes...
 

Silver Member
Username: Invain

Michigan United States

Post Number: 141
Registered: Aug-04
Well, first I don't think the ground would make it get hot. Running it at 2 ohms will make it get hotter than 4, but it shouldn't get hot after 5 minutes.
 

Bronze Member
Username: Document_c

NY

Post Number: 18
Registered: Sep-04
It's a sony, 'nuf said
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1597
Registered: May-04
A ground can cause this problem. Again, like said above, not trying to be mean, but Sony makes horrible amps. Poorly designed, overheating is common with them, as well as failure overall.
 

Silver Member
Username: Insearchofbass

Post Number: 526
Registered: Jun-04
current travels from the ground first believe it or not and you should have the same size ground as your hot wire the ground should be as short as possible as well
 

Silver Member
Username: Insearchofbass

Post Number: 527
Registered: Jun-04
run some fans over your amp to cool it
 

Bronze Member
Username: Ctx

Post Number: 49
Registered: Jun-04
its cuz big dumb audiobahns try to suck way more power then the amp produces ive had many a problem with audiobahn setups
 

thedirk
Unregistered guest
your just trying to suck to much power from an amp that doesnt have it, your amp should always be rated higher than tha subs, in my opinion, talking about rms rating
the dirk.
 

New member
Username: Yuper

Post Number: 1
Registered: Sep-04
HI, Im having the same problem with my Jenson amp. I am running it briged mono and the amp spec is about 250RMS 720 peak. I am running it with a JBL 12" sub and a 8 gage streetwire kit. After about 45 min. the amp just shuts down and it is HOT. I guess its just because it is a cheap amp eh? What do you expect for 30$ on ebay! lol
 

Anonymous
 
yeah, jensons are worse than sony in my opion...i'd say invest in a new amp! I have a 1000watt peak sony powering my 15" kicker comp VR, and it pounds it hard and sounds awesome, and does not over heat, after i rewired my sub in series
 

New member
Username: Yuper

Post Number: 2
Registered: Sep-04
What do you guys think of a JBL GTO 301.1 Amp?
 

Bronze Member
Username: Fishy

Tamarac, FL USA

Post Number: 63
Registered: Sep-04
lol, sure beats the hell outa Jensen IMHO.

Whats the impedance(ohms) on that sub? Is it dual voice coil?

-Fishy
 

New member
Username: Yuper

Post Number: 3
Registered: Sep-04
Its a 4 ohm single voice coil. see it here http://jbl.com/car/products/product_detail.aspx?prod=GT120&ser=GTS&cat=SUB
 

Bronze Member
Username: Fishy

Tamarac, FL USA

Post Number: 74
Registered: Sep-04
Well that impedance wouldn't normally pose a problem for a "typical" 2 ohm stable 2 channel amp.

According to the specs I saw that 301.1 will deliver about 200 watts into a 4 ohm load.

Most of the guys here seem to recommend the older BP series tho. Specs on the BP300.1 say 150 watts @ 4 ohm.

Anything will probably be an improvement tho, hehe.

-Fishy
 

Gold Member
Username: Its_bacon12

Hfl, Ny Usa

Post Number: 1006
Registered: Dec-03
you need a 4 guage ground, never do what youve done and use a smaller guage for the ground, it will mess up your amp and end up frying it
 

Bronze Member
Username: Fishy

Tamarac, FL USA

Post Number: 76
Registered: Sep-04
OK, explain that one to me Bacon.

I know its always better to use the same size wire for power and ground(otherwise you're kind of wasting the larger size), but how exactly will not doing this "fry" your amp?

If you view your chassis as one big ground wire it seems like it would think itself a pretty heavy duty wire at that, or is it only bad if your ground wire is "smaller".

I really don't think electrons care too much about "power" or "ground". To them its just one big race from point A to point B with some rush hour traffic thrown in sometimes.

-Fishy
 

New member
Username: Thedirk

Potsdam, NY

Post Number: 8
Registered: Sep-04
oh noo, it makes a huge differnce on wire size, the bigger the wire the better, the shorter the ground the better...
thedirk
 

Gold Member
Username: Its_bacon12

Hfl, Ny Usa

Post Number: 1007
Registered: Dec-03
the bigger the ground guage and the shorter the better

the smaller guage ground restricts the amount of flow going through it, thus regtulating how much power the amp takes in which isnt good especially if it's under-drawing the amount of amperes it needs to properly run, the amp will clip, eventually destoying your subs and possibly the amp too
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1696
Registered: May-04
Yep. Voltage rails will sag, clipping the amp and also building up a lot more heat in the amp. Picture an water pump with a hose coming to it and a hose going out. When you have equal water coming in and going out, everythings in working order and it'll likely pump for a very long time. Now pinch the inlet hose, the pump will be forced to pull very hard and will get much less water, limiting the output as well, straining the pump motor and eventually burning it up if it carries on for too long. Same with an amp, a smaller ground is a pinched hose basically. Remember that your system is only as good as it's weakest link, and the smallest wire will be the one that has the most resistance, and since the current has to go through that wire, that resistance will be added to what resistance was already in the chassis, and will be more total resistance than the power wire.
 

New member
Username: Yuper

Post Number: 4
Registered: Sep-04
is an 8 gage kit is fine for the amp I have? The jenson or JBL301.1.

Yuper
 

Bronze Member
Username: Fishy

Tamarac, FL USA

Post Number: 97
Registered: Sep-04
Yeah, obviously having too small a power or ground wire is not a good thing, but having two different size wires is not gonna hurt anything as long as the "smallest" of the two is big enough to do the job, or am I missing somethin here?

-Fishy
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1704
Registered: May-04
It can still create problems. You have impedance differences, which can generate noise in the system and still fluctuate power delivery.
 

Bronze Member
Username: Fishy

Tamarac, FL USA

Post Number: 98
Registered: Sep-04
As far as the pinched hose analogy goes, well I'm not sure that exactly holds water, so to speak. The resistance in a wire depends a whole lot on how long it is as well. See here:

http://www.epanorama.net/documents/wiring/wire_resistance.html

If you notice 4 gauge wire has only about 2 1/2 times less resistance per length than 8 gauge. So assuming you have a really good ground(and can assume the resistance in the chassis to be very small), a one foot 8 gauge ground wire with an 8 ft run of 4 gauge wire may actually result in a HIGHER resistance on the power side of things(depends on chassis resistance).

I'd say in the case of a ground wire, length is every bit as important, if not more, than the "size". For example a 1 ft length of 8 gauge wire has less resistance than a 3 ft length of 4.

I only say this because I'm utilizing an older 400 watt PPI amp with what seems to be fixed 10 gauge(or real skinny 8) power and ground wires comin out. Unless I break open that amp and solder in some bigger stuff I'm stuck with that 10 gauge "bottleneck".

Instead I just keep them jokers really short.

-Fishy
 

Bronze Member
Username: Zacdavis~

Post Number: 24
Registered: Sep-04
fishy is right jonathan, think of power goin thru the fuse, very small, but very short, also the ground he has is equal to the positve after you average the legnths
but back to the question, i think you guys are right that it is being ran at to low of an impedence causin the overheating
 

Gold Member
Username: Its_bacon12

Hfl, Ny Usa

Post Number: 1013
Registered: Dec-03
touche
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1709
Registered: May-04
Absolutely, it has an effect, but you also have to consider that the positive wire is a straight run to the battery, while the ground connects to the chassis of a vehicle, in which the impedance is unknown, and likely higher than the impedance that the power wire has. So, you're better off getting a bigger ground wire and keeping it short, so that the impedance that comes through the chassis and ground is as little as possible. Touche
 

Juggalo Jeff
Unregistered guest
tell me this then i have bought amp wiring kits from meijer before the brand is scosche or somethin i consider the kits to be pretty good for the price 4 guage wiring kit is like 25 bucks how come they give u 4 guage power wire but 8 guage ground just wonderin im thinkin of eventually gettin 4 guage ground tho.
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 200
Registered: Sep-04
They probably expect you to use the 4 to 8 gauge distrubution block and run 8 gauge power to your amp(s) and then an 8 gauge ground(s). If the kit came with an extra 4 gauge ring terminal just cut a bit off the power cable, crimp on the terminal, and use it for ground. You can wrap it in black electrical tape so the color doesn't confuse anyone(I did :P).

-Fishy
 

Unregistered guest
I have a sony 480 watt amp powering a 12 sony sub enclosed in a bandpass box. my problem is that after about ten minutes or sometimes less the bass cuts out for about 5 seconds and then comes back. if i dont turn the stero off it continues to do this repeatedly. my volume is usually about halfway up when this happens but sometimes it does it reguardless. is it the ground or do i need a bigger amp?
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