4 ohm Output

[Dunc]

Hi, First time poster
I currently have a Sony DAV FCP Theatre in a Box system and the unit is starting to crap out. (It produces a high pitched squeal on initial startup and dissipates after about a minute)
I'm thinking I'd like to replace it with either a Harman Kardon AVR 146 or a Yamaha HTR 6040 and would like your opinions on whether these 2 units will accomodate the 4 ohm load that the sony speakers are rated at.
It has been very difficult finding any information as to the pitfalls of running a set of 4 ohm speakers from the 8 ohm output

Thanks
Dunc

 

[Davemcc]

Welcome to the forum.

I can't find any Sony DAV FCP product information. Perhaps you could double check the model designation and confirm that.

A quick check confirms that both the receivers you are looking at are 4 ohm capable.

As to the pitfalls of running 4 ohm speakers, I'm just going to cross my fingers and hope I get the explanation right and, as always, I stand ready to be corrected. Anyways, the reduced impedence of a 4 ohm speaker does not offer as much resistance as an 8 ohm speaker and causes the receiver to output more current to the speaker. If the receiver is not designed to output that much current, it might overheat and fry itself.

Let me also be the first to suggest that you begin speaker shopping and auditioning as soon as you have a usable receiver.

 

[Dunc]

Hi Dave
Thanks for the quick reply
My mistake it is a DAV FC9
The Yamaha unit has settings for 8 and 6 ohm's Would it be prefferable to run this at 6 instead of 8?
At this time I'm hoping to just replace the receiver and not worry about the speakers. The unit is at my fathers and he's 80 and going deaf. For the most part he turns it on in the morning and shuts it off at midnight. He tends to have it fairly loud and my main concern is that it will run too hot and go into protection mode or worse.

Thanks
Dunc

 

[MDS]

If you set the impedance selector switch to 6 ohms instead of 8 it will reduce the available rail voltage thus reducing the amount of current available.

If you are concerned about possible overheating or tripping the receiver's protection circuit, you should set it to 6 ohms.

 

[Dunc]

6 ohms it is.

Thanks
Dunc