Car audio ohm question...

[Pastore]

I have a pair of MTX 6x9's, and would like to power them with a Thunder4202 amp. The amp is rated at 100W x 2 @ 2 ohms. Do speakers have ohm ratings that are speaker specific? And would this work?

 

[minendo]

Yes speakers are usually ohm specific. What model speakers are they?

 

[Colt45]

doesnt really matter..

 

[minendo]

Originally posted by: Colt45
doesnt really matter..

Depends on how much the speakers can handle.

 

[Pastore]

They are MTX 6922... They are rated at 80W RMS and 120W Max... But I can't find any ohm ratings on the speakers, and don't have the original documentation...

 

[minendo]

Originally posted by: Beast1284
They are MTX 6922... They are rated at 80W RMS and 120W Max... But I can't find any ohm ratings on the speakers, and don't have the original documentation...

They are rated at 4 ohms.

 

[Pastore]

ok, this site says they are 4 ohms, so what would it happen if I hooked up that amp? Just cut the rated power in half to each channel?

 

[minendo]

Originally posted by: Beast1284
ok, this site says they are 4 ohms, so what would it happen if I hooked up that amp? Just cut the rated power in half to each channel?

Double the power to each channel.

 

[Pastore]

So it would be pushing 200W per channel? WOuldn't that fry the amp/speakers pretty quickly?

 

[Colt45]

it will work fine.

if you want to get difficult, the output transistors will see a lighter load, and (with tubes at least.. im not sure about SS) this leads to a little power loss (not really noticible) and less distortion.

but yeah, the thing will work 2/4/8, SS isnt very picky..

probably designed for 4 & 8 ohm speakers.. often they just use the 2ohm or 1 ohm to say its stable down that low..

 

[minendo]

Originally posted by: Beast1284
So it would be pushing 200W per channel?

No the amp would still push 100W x 2 while the speakers would actually actually be 160-200 per channel.

 

[Pastore]

Originally posted by: minendo

Originally posted by: Beast1284
So it would be pushing 200W per channel?

No the amp would still push 100W x 2 while the speakers would actually actually be 160-200 per channel.

I am officially confused... Just when you think you know something about car audio, it just gets more complicated...

 

[minendo]

Originally posted by: Beast1284
I am officially confused... Just when you think you know something about car audio, it just gets more complicated...

As you double the ohms a speaker takes, the power it can handle reduces by 1/2. The same goes for decreasing the ohms the speaker runs at except that the handling power doubles.

Say you have 4ohm speaker rated at 100W, then running it at 2ohm would allow 200W max. Running it at 8ohm would allow 50W max.

 

[Pastore]

So basically I would fry the 6x9's in a heartbeat right?

 

[minendo]

Originally posted by: Beast1284
So basically I would fry the 6x9's in a heartbeat right?

NO because you would be feeding them 100W x 2 while they can handle 200W max at 2 ohms.

 

[Pastore]

so at 0 ohms they could handle 400W?

 

[minendo]

Originally posted by: Beast1284
so at 0 ohms they could handle 400W?

Actually by carrying out the equation I=V^2/R you get an undefined answer.

 

[Pastore]

ok 1 ohm

 

[glen]

In the end "amps" don't matter nearly as much as "swept air" or X-max times surface area.

 

[Pastore]

so the ohm is a measure of impedance right? so the reason it can handle twice the power is because the power is being resisted much less? am i understanding this correctly?

 

[Howard]

0 ohms is impossible, especially in crappy speakers like those.

 

[Pastore]

this site says the following...

An amplifier amplifies the electricial signal, causing the speaker to vibrate with greater force, otherwise the impulse would be barely audible. How much the amp drives is measured in watts. When an amp manufacturer gives it's wattage rating, it's always at a specific Ohm resistance. 100 watts @ 4 ohms, for example. When the resistance is 4 ohms, this amp will produce 100 watts. If that resistance changes, the amp will produce a different amount of watts.

 

[minendo]

Originally posted by: Beast1284
this site says the following...

An amplifier amplifies the electricial signal, causing the speaker to vibrate with greater force, otherwise the impulse would be barely audible. How much the amp drives is measured in watts. When an amp manufacturer gives it's wattage rating, it's always at a specific Ohm resistance. 100 watts @ 4 ohms, for example. When the resistance is 4 ohms, this amp will produce 100 watts. If that resistance changes, the amp will produce a different amount of watts.

Yes that is if you wire the amp to run at different ohms.

 

[XCLAN]

Originally posted by: Beast1284
ok 1 ohm

btw 1 ohm would toast yer amp over tme if you could get it to run at that ...i have a mtxthunder 4200x and it will not run 1 ohm

 

[XCLAN]

Originally posted by: Beast1284
so the ohm is a measure of impedance right? so the reason it can handle twice the power is because the power is being resisted much less? am i understanding this correctly?

yes u understanding correctly