Help...Receiver/speaker matchup

[bluseminole]

Well, I am about ready to pull the trigger on a pair on Revel Concerta F12s after several months of saving & listening. My current receiver is similar to the old Onkyo HTR-540, but is the version they included with their HTS-790 HTiB. My question is: can this receiver drive these speakers?

I know that the receiver is rated at 8 ohms, and the speakers are 6 ohms nominal. This is bad. The receiver overheating is unlikely except under heavy loads; it is out in the open with many many feet of ventilation space.

I have a stereo anthem amp (MCA-20), but because my receiver lacks true pre-outs, I need to use the tape-outs, run to a separate pre-amp do-job (its a five-channel personal mixer ), then to the amp, volume-matched with an SPL meter to the other 5 speakers powered by the receiver. This is a temporary measure. But, this only works for analog sources. So for movies and music (I use analog MC), these speakers would be powered by the anthem...no problem. For TV and gaming (digital optical connection), however, they would be powered by the receiver. TV is not nearly as taxing, so my question is is it okay to run these 6ohm speakers with my cheapish 8ohm receiver, or will the receiver melt and blow up, even though I won't be pushing the speakers?

(The receiver does have a protection circuit that I have engaged before while experimenting with a homemade ESL)

[bluseminole]

^

[Beta Man]

"Yes" Worst case scenario you damage the AVR.... the speakers will be fine, so that's the important part. (But I'm guessing you won't damage anything)

[bluseminole]

Thanks. If the receiver is damaged, will it typically just be the amplifier section, or the power supply itself?

[Blu-Dog]

Originally Posted by bluseminole

Thanks. If the receiver is damaged, will it typically just be the amplifier section, or the power supply itself?

You can cause havoc all around, in both the receiver and the speakers.

The lower resistance of the speakers will cause spiked output from the receiver. The spikes won't be sustained; there is only so much power that can be snagged from a transformer. But the amplifier also has capacitors, that attempt to store power in reserve for loud transients, and they tend to unpredictably cut loose when you're hauling juice out of there with a low resistance load.

So while you expect only the maximum rated power coming out of your unit, at worst, you may actually have a brief, violent spike many times the rated output of your receiver.

Tweeters are the usual victims of these events.

Keep the volume way down until you get a receiver or amplifier rated correctly for a 6 ohm load.

[Driver_King]

Your comment about those 6ohm speakers and the AVR worry me more. I have the Onkyo 805, which is designed to power 4 ohm speakers, but am powering some power hungry SDA II speakers, two Polk Monitor 5Jr's, and two Polk Monitor 4's all at the same time and at very loud volumes. I like to listen at reference volumes whenever possible too and am wondering how my 805 will take another power-hungry speaker, a CSi A6 center channel. What an expensive hobby. I need to get all of this within one month:

1. A new projection screen
2. My new projector
3. The Polk CSi A6 center channel- in cherry
4. A new center speaker stand
5. Make mounts for for my back-surrounds
6. Get a new ceiling mount for the new projector

Boy, oh boy!

[Nathan P]

Originally Posted by Driver_King

Your comment about those 6ohm speakers and the AVR worry me more. I have the Onkyo 805, which is designed to power 4 ohm speakers, but am powering some power hungry SDA II speakers, two Polk Monitor 5Jr's, and two Polk Monitor 4's all at the same time and at very loud volumes. I like to listen at reference volumes whenever possible too and am wondering how my 805 will take another power-hungry speaker, a CSi A6 center channel. What an expensive hobby. I need to get all of this within one month:

1. A new projection screen
2. My new projector
3. The Polk CSi A6 center channel- in cherry
4. A new center speaker stand
5. Make mounts for for my back-surrounds
6. Get a new ceiling mount for the new projector

Boy, oh boy!

If your worried about the power you could always use the pre outs on the 805 and add an amp - more upgraditis