amp loads

[neomagus00]

aight, quick question: what happens if you drive an amp to a too-low impedance? say if it's designed for a minimum of 2 ohms / channel and you put 1 ohm on a channel? i know that the voltage will ramp up twice as fast, so you can't turn the volume knob up as far (though you will get the same dBs out of it with that reduced travel)... are there any other effects? if so, a technical explanation would be appreciated, if it's available...

[mbdyer12]

From past experience, it gets REALLY hot and fries like throwing a box of garbage bags in a camp fire. Ohh that was fun.

Of course, this was with a DHD amp. Haha...

[exalted512]

from my understanding...amps that are not made to go down to 1 ohm has everything to do with the materials used inside the amps
theyre not made to handle that kind of load...so if you put a load on them that they cant handle...stuff breaks
as far as my technical explanation
"shit breaks"
-Cody

[Joelsbass]

it's a realy good way to let the magic smoke out of the amp....

[dougie07]

By decreasing the resistance (2 ohm load to 1 ohm load), you increase the current flow (amperage). And when you try to increase the current flow through wires, and other parts in the amp that can't handle that much current flowing through them, they start to heat up. When they heat up, stuff starts to burn, melt, etc. I know Cody said the same exact thing, I just thought I'd throw a few technical terms in there to expand on his technical explanation a bit. :D

Doug

[neomagus00]

awesome - the stuff before dougie's post saved a good amp, and dougie explained why I have to spend more money... thanks guys (gals? are there any here?)...

[LittleCar_w/12s]

in addition... even if you ran the amp at the say, 1ohm vs the rated 2ohm, and only turned it up half way so that it outputted out a wattage within it's limits, the lowered impedance will create havoc with the feedback circuits in tha amp and the THD become very bad.

[MacLeod]

Thats evident even when running at 2 ohm loads. Most amps THD distortion triples at a 2 ohm versus a 4 ohm load so you can imagine what a 1 ohm load would be like. 6% THD?

This is the reason I dont like bridging 4 channel amps to run as 2 channels.

[PoweredByDodge]

as stated... if an amp is rated (lets speak more practically) at 4 ohms bridged... and you run it at 2 ohms bridged...

now the amp is rated at 300 watts x 1 bridged at 4 ohms... and u run it at 2 ohms, but stay at or below 300 watts of power output.

so you're not going to HURT anything... but...

damping factor is cut to 1/4 or something aweful like that... thd goes up - random bad shit.... etc etc

[Jstas]

Originally posted by MacLeod
Thats evident even when running at 2 ohm loads. Most amps THD distortion triples at a 2 ohm versus a 4 ohm load so you can imagine what a 1 ohm load would be like. 6% THD?

This is the reason I dont like bridging 4 channel amps to run as 2 channels.

It actually depends alot on the amp. D class and T class (new) seems to be more resilient at lower impedance levels. It's the A and AB class amps that have troubles with low impedances the most.

Consequently, you see massive power house D-classers with thousands of watts avaiable at 2 ohm and below impedances but THD rathings in the 1-2% range. That's pretty good for such a large amount of power. Class A and AB amps will get decidedly ugly the lower you go. That is mainly because of the way the power supplies and circuits are designed. D class is beefy and often over built by most companies for what the amp will be doing. A and AB amps are not always as big and powerful but rely more on finesse than brute force. The T class amps are very much like D-class but with a wider frequency band.

I realize it seems rather sophomoric to use such general terms to describe something so specific but without diagrams and an understanding of circuits, it's difficult to get the idea across accurately.

[MacLeod]

Originally posted by Jstas

I realize it seems rather sophomoric to use such general terms to describe something so specific but without diagrams and an understanding of circuits, it's difficult to get the idea across accurately.

Dont sweat it bro, youre speaking my language; slow and with small words! ;)

[exalted512]

is this the reason why most component speakers are 4 ohms and not 2??
-Cody

[neomagus00]

jstas - i do have a bit of understanding on this, and it interests me, so pm me if you've got anything like that (and we can save mac the headache :D)

[jamas33]

If you do that.. you can save alot of money.. instead of buying a George Foreman Grill you can just use the AMP. Make sure bring some sauces for marinating