Ohms!! my head hurts!

[tnuthals]

Ok...i've been digging through information about speaker impedance for awhile and now my head hurts. I have a couple questions/hypothetical situations andI need you folks to set me straight.

I'm planning on getting a pair of Polk Lsi15s (rated as 4ohms) to be my new fronts. I currently have a yamaha 663 as my receiver.

First, according to the manual, I can change the speaker impedence setting to 6 ohms.....thus allowing me to use fronts that are rated at least 4 ohms...as long as my center and two surrounds are 8 ohms (which they currently are).
Is this assumption correct??

Second, If i wanted to upgrad my center and rears to lsi9s and an lsic, I would not be able to use my receiver....unless i got an amp?

Should I just invest in an amp now?
Should I start shopping for a new receiver?

Help, thanks.

[Bear28]

Originally Posted by tnuthals

Ok...i've been digging through information about speaker impedance for awhile and now my head hurts. I have a couple questions/hypothetical situations andI need you folks to set me straight.

I'm planning on getting a pair of Polk Lsi15s (rated as 4ohms) to be my new fronts. I currently have a yamaha 663 as my receiver.

First, according to the manual, I can change the speaker impedence setting to 6 ohms.....thus allowing me to use fronts that are rated at least 4 ohms...as long as my center and two surrounds are 8 ohms (which they currently are).
Is this assumption correct??

Second, If i wanted to upgrad my center and rears to lsi9s and an lsic, I would not be able to use my receiver....unless i got an amp?

Should I just invest in an amp now?
Should I start shopping for a new receiver?

Help, thanks.

From the info I received when I was looking at getting a new receiver, you want to make sure that:

The ohms of the speaker (4) should match what your receiver manual says. So if your receiver states between 4-16, you should be ok. But if it states 6-16, then you run the risk of blowing your speakers because it might not be able to handle what it is receiving.

Hopefully though someone with more knowledge than myself can reply and help you out some more!

Thanks

[tnuthals]

see now I was thinking the opposite...the receiver wouldnt be able to handle powering the speaker and the receiver would blow?

[gamer2600]

You will be able to still use your receiver you just aren't driving those speakers to what they should be getting. The speakers that you are looking at should have a separate power amp to drive them correctly. Its not like the receiver isn't going to work with the speakers.

[tnuthals]

Originally Posted by gamer2600

You will be able to still use your receiver you just aren't driving those speakers to what they should be getting. The speakers that you are looking at should have a separate power amp to drive them correctly. Its not like the receiver isn't going to work with the speakers.

So if i was shopping for a power amp.....and planning on upgrading my center and fronts ( which we always are) would i want to be looking at a 3 channel amp and 2 channel amp for a 5.1 system? any recomendations other than emotivas?
if the emotiva is rated as 3 channels at 4 ohm = 300 watts per channel and the speakers have a recommended wattage of 50-250 watss...can the power be adjusted on the power amp?

[Twitch9]

You will be fine you just can't go the other way, if you use your amp at 4 ohms on speakers rated 6 or 8 ohms you will blow the speakers and possibly damage your receiver. 4 ohm speakers on a 8 ohm amp is fine.

[gamer2600]

Originally Posted by tnuthals

So if i was shopping for a power amp.....and planning on upgrading my center and fronts ( which we always are) would i want to be looking at a 3 channel amp and 2 channel amp for a 5.1 system? any recomendations other than emotivas?
if the emotiva is rated as 3 channels at 4 ohm = 300 watts per channel and the speakers have a recommended wattage of 50-250 watss...can the power be adjusted on the power amp?

All depends on your budget...there are 5 channel amps, there are 7 channel amps, you could even get monoblock amps for each channel. Emotiva makes great amps from what I heard and I am looking to get my hands on one someday soon...as soon as I figure out my receiver situation which is another story .

[Big Daddy]

Your speakers and your receiver will not blow. This not a war.

If a receiver is rated for 6 or 8 ohm only, you can still use it on a 4 ohm speaker. However, you need to make sure the volume is not very high and you need to check the receiver for overheating.

Low impedance speakers draw more current from a receiver. If the receiver or amplifier is not rated for low impedance speakers, it will get hot. It will not blow. If you play your music/movies too loud, it will gradually fail and may or may not cause some damage to your speakers.

Receivers/amplifuers that are rated for low impedance speakers can handle 8 ohm speakers with no difficulty.

It is helpful to read Impedance and Sensitivity of a Speaker. It has a sticky in the Speakers section.

[pearsall001]

The LSi series speakers are superb sounding. However they do need proper amplification to let them perform at their best. Your AVR will drive them, just not good enough though. An external amp is in order here. A 4ohm load is a tough cookie to handle for the majority of AVR's. Especially if you're thinking about going with the LSi series all the way around.