Onkyo 646 problem :(


Active Member
Hi All,

I have an issue with my Onkyo 646 in that it has over the years had an intermittent problem. It it will go into protection mode randomly and tell me to check speaker wire. It has done this on and off once in a blue moon over the years and occasionally flared up doing it frequently for about a week then dropping off and being fine again for ages.

It has for the last year or so been making a clicking sound randomly once every 30 mins to an hour or so during playback of audio from any source. The sound is like the sound that onkyo's are infamous for when you change input sources or turn the receiver on, that clunky click. But when this happens during playback (except for when it bombs out as detailed above) there is no interruption to audio or video.

When it has bombed out completly, the message has always been to "Check speaker wire". I used to run bare wire when I first had the issue but have since moved to banana plugs at both ends (in case of a stray strand of wire causing a short) and have reterminated them over time and now even baught pore terminated cables and am still having the issue. I would hope that this rules out the cables by now.

Speakers are listed below in case ther could be an issue around them? It is work noting that the rears are seldom connected due to the room layout and only rolled out for movies (the heights are always connected) and that this issthe issue has happened when all speaker are connected and when only the front and centre's have been connected. Also worth pointing out that I have had an RSLCR centre connected (still had the issue), then a newer (5G) silver centre which one of the driver blew (was an ebay job so could have just been bad luck). This has been replaced with the C350 mentioned below and I am worried that if the last centre died because of some short or surge that my other speakers may just be waiting to fry.

Receiver is plugged into a surge protector/ mains conditioning extension lead. No other devices connected to this have exibited any issues. The unit is never run super loud (volume level 35 tops). Normal listening level for me is between 20 & 30.

FRONT - Monitor Audio Silver RS6
Frequency Response
38 Hz - 30 KHz
Sensitivity ([email protected])
91 dB
Nominal Impedance
6 Ohms
Power Handling (RMS)
120 W
Recommended Amplifier Requirements
40 - 120 W

CENTRE - Monitor Audio Silver C350

Frequency Response (-6 dB)
40 Hz – 35 kHz
Sensitivity ([email protected])
90 dB
Nominal Impedance
8 ohms
Minimum Impedance
3.2 ohms @ 176 Hz
Maximum SPL
113 dBA
Power Handling (RMS)
200 W
Recommended Amplifier Requirements
80 – 200 W

Monitor Audio Silver RS1

Cambridge Audio SX50

If anyone has any experience or thoughts, that would be appreciated. I did enquire about getting it looked at under warranty with Richer Sounds but they would have to take it and teast it until it happend and it soo intermittent that it could literally be months or even close to a year before it happens so that was not feasible to lose it for months and potentially not have them see the fault.

Any help is appreciated.


Active Member
Nobody? :(

The latest video from AVForums

Panasonic LZ2000, LZ1500 & LZ980 Hands-on Launch Event | No QD-OLED for 2022, new 77-inch for LZ2000
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom