ohms. can i change them??

[figgie]

Years ago, when I was into car stereos, the only real difference between a 4 ohm stable amp and a 1 ohm stable amp was better cooling and different marketing materials.

I haven't kept up on the field, so things may well have changed since then, but I seriously doubt it can hurt to wire it in 2 ohm mode, and if it shuts down from heat, just change it to 8 ohm mode.

I've never seen an amp do anything when overloaded, at least not in the sound quality department. I've run them hot enough to melt all the solder on the mainboard. Then all the components fell out, the amp stopped working, and when it cooled down enough to pick up, it sounded like a baby rattle. I've had one or more channels just stop working. That's about it.

Grim

You are talking back in the Day of the Orion HCCA amps The first amps for car audio that could double the power every time you dropped the resitance by 1/2.

HCCA 25 stable to .5 ohms

And Grim is right. When over loaded an amp will just shut off from thermal overload not because of any other reason.

 

[Fuzz420]

Grim

You are talking back in the Day of the Orion HCCA amps The first amps for car audio that could double the power every time you dropped the resitance by 1/2.

HCCA 25 stable to .5 ohms

And Grim is right. When over loaded an amp will just shut off from thermal overload not because of any other reason.

I have the HCCA'S brother, the XTR "beast" its only rated @ 1000w @ 4 ohms, but trust me when i say there were zero issues @ 1 ohm.It just ran on the toasty side

 

[GrimJack]

Yup, that's the stuff I'm talking about. I run HiFonics series VIII gear - not *quite* as good as the HCCA, but the shop I worked at only carried Kenwood, Rodek, and HiFonics, so I got hookup deals. I'd have had to pay full price for Orion gear.

 

[FullNelson]

well i wired it back at bridged with a 2 ohm load. and after latting it play for a while, it doesnt really get to hot, only warm to the touch. it did start to clip, but it was only when i was adjusting the gain. right now the amp is rated at 800watts at 4 ohms briged. when you calculate roughly the amp power based off of fuses, what resistance is that? ie. i have a 105amp fuse x 14.4 gets me 1512watts intake. its an ab amp design, so its pushing maybe 750watts, is that at 1, 2, or 4 ohms? or am i way off?

 

[Dan_Gyoba]

Way off...

If it's rated for 800W at 4 ohms, you might get 1300W at 2 ohms (Theoretically, it should be 1600, but that's only if the the PSU is going to be able to supply that before the voltage drops, and it isn't.)

Basically, what the fuse means is that if your PSU draws the 1512W, the fuse will blow. That has no real bearing on what the amp is capable of putting out on the other end. This is why the fuse value is not a good indicator of how much power your amp has, but it CAN be an indicator of how much power it does not have. For example, if you see an amp that's rated for 300W, but it has a single 20A fuse, this means that as soon as you get 288W from the battery (Assuming 14.4V) the fuse blows. As a result, you can be sure that the PSU there cannot ever have more than this available to it, so you have to start wondering how the amp can be rated for 300W. However the reverse is not true. I could just as easily stuff a 40A fuse into that same amplifier, with no other changes. That will not allow it any more power, but then nobody can look at the fuse and say "there's no way that can ever get to 300W."

High end stuff is usually overspec, so it will often take more abuse than it's rated for, but it will ALWAYS come at a cost of higher distortion.

Halving the resistance to double the power (Again, provided that the PSU can keep up) will gain you 3dB SPL, and will dramatically increase the distortion.

 

[FullNelson]

thats makes sense. i was a little lost on the fuse calculation. yeah, i wuldnt want to take the little spl advantage over distorion right now with the risk of hurting anything when i still have another amp and sub on its way to maybe up for the spl. thanks for the advice

 

[buldozr]

Most what was said is pretty accurate, the most important note was the inline fuse within 12-18" of the battery(extremely important). Cheap amps overrate their amps, high end amps under estimate, in this case, sound quality would be a concern if running regular speakers, but what was mentioned before, with subs (below 500hz), a Monoblock class D would be a good choice(dont be scared of the low watt output advertised, class D's purpose built to do the nasty)