Amp type questions

[RoMeRz]

Got a nice amp head yesterday and wanting to ask a few questions. They may be silly and basic - but we all need to learn.

It says no lower than 4ohms. Am I right in thinking that means no 2ohms speakers - only 4ohms and 8ohms yes ?

It is 350watts - I dont have a cab yet - but I have access to two 250w 8ohms speakers - will they be of any use and what will the result be ?

Also will I need to use "speaker" leads rather than just normal leads ?

[RoMeRz]

* bump *

[muthafunkabass]

1. yes
2. 350 watts at 4 ohms or 8ohms?
3. yep

[RoMeRz]

that was a typo - its 300 watts - I *think* that would be at 4ohms.

[flea_slap_god]

you cant use 2 4ohm cabs, either 2 8ohms, 1 4ohms i think. could be wrong.

[Killer Fridge]

exactly, 2 8ohms or 1 4ohm

[bbbbass]

Would this happen to be an Ashdown MAG 300?

[Sade]

You simply cannot have ohms that exceed 4 ohms. Remember these patterns:

8+8=4
4+4=2

[Jimbobntnr]

You simply cannot have ohms that exceed 4 ohms. Remember these patterns:

8+8=4
4+4=2
ohms have to exceed 4
8 & 8 = 4 in parrallel and 16 in series.

[Sade]

ohms have to exceed 4
8 & 8 = 4 in parrallel and 16 in series.

Yeah, it's in reverse, so I was attempting to explain it in a way he'd understand. The most common way it's read is 8+8=4 in parallel.

[bbbbass]

Ohms Law, people, look it up.

[TheBassman238]

Whats size are these speakers you talk of and what were they normally moent for, that will have a large impact on what it sounds like.

-TBM

[LewsTherin]

Ohms Law, people, look it up.

we're not all electricians here.


But for your amp, 4 ohms is the nominal impedance. This is the impedance it "likes" to run at.

With solid state amps, you can run your amp at any impedance equal to or higher than its nominal impedance (so with a 4ohm nom, you could run it at 4, 8, 16, etc). You can NOT, however, run it below its nominal impedance. This = bad.

Keep in mind, also, that running an amp above its nominal impedance will reduce output wattage. (running below will make the amp try to exceed what its supposed to put out, therefore overheating and frying the poweramp).

Think of it this way: You're used to walking through a foot of water. Its the only way youve ever walked.

All of a sudden, theres 2 feet of water. You can still walk, you just go slower. This is what happens when you run an amp above its nominal impedance...it works less well.

If there were only a thin film of water, however, you'd end up walking faster than normal and slipping and cracking your skull open. THAT is what happens to your amp when its run below its nominal impedance. It slips in a puddle.

[LewsTherin]

Oh, and yes you do infact need to use speaker cables. Instrument cables are not meant to transmit the power put out of a poweramp.

[muthafunkabass]

we're not all electricians here.


But for your amp, 4 ohms is the nominal impedance. This is the impedance it "likes" to run at.

With solid state amps, you can run your amp at any impedance equal to or higher than its nominal impedance (so with a 4ohm nom, you could run it at 4, 8, 16, etc). You can NOT, however, run it below its nominal impedance. This = bad.

Keep in mind, also, that running an amp above its nominal impedance will reduce output wattage. (running below will make the amp try to exceed what its supposed to put out, therefore overheating and frying the poweramp).

Think of it this way: You're used to walking through a foot of water. Its the only way youve ever walked.

All of a sudden, theres 2 feet of water. You can still walk, you just go slower. This is what happens when you run an amp above its nominal impedance...it works less well.

If there were only a thin film of water, however, you'd end up walking faster than normal and slipping and cracking your skull open. THAT is what happens to your amp when its run below its nominal impedance. It slips in a puddle.
you type that metaphor everytime we get one of these threads.:lol:

[LewsTherin]

you type that metaphor everytime we get one of these threads.:lol:

hey, its a good metaphor!


i should just save it and copy-paste it everytime. as of now, i actually have to type it out.

[d-basser]

1/R total= 1/R1 + 1/R2...

ie one apon total resistance is equal to one apon the first resistance plus 1 apon the second resistance and so on

[RoMeRz]

Sorry for making "one of these threads" I just wanted to ask some specific questions as to not get confused. Sorry people :(