How hot is the Onkyo getting when it shuts off? Back in the day I owned an Onkyo AVR. The thing got so hot that I could easily fry an egg on it. There was plenty of room for ventilation too. Scared me so much so that I sent it back not long after and went with Denon instead. Honestly, it sounds like the protection circuity is kicking in which will temporarily shut it off until it cools down to safe levels. Make sure all of the connections are sound. Especially, the speaker connections. Are you using banana plugs?
Cheers,
Phil
The 656 I owned didn’t suffer from the heat issues of the older models. In addition, almost every onkyo avr I’ve owned or seen bench tested had very little in the way of current limiting when compared to other manufacturers. If you look through S&V bench tests of both old and new onkyos, you’ll see that even their lowest models such as the 656 delivers the full rated 2ch power into all 7ch under .08% THD. This has little to do with onkyos simply having better power supplies and more to do with other brands employing more cautious limiting.
I actually blew the Surround left output transistor in the 656 I owned by attempting to drive a low impedance difficult load at a high volume. By the time the avr went into protect mode, it was too late. With an older onkyo I owned, one of my surround channels had a minor short in the connection from spliced wires I failed to tape up properly. The only reason I discovered the problem was because the output would clip at a high volume, not once did the avr shut off.
The onkyo mentioned above developed issues with the sub preouts and was replaced with a newer model. Out of curiosity, I put the retired avr through a torture test by wiring a dvc 2ohm car sub to the front channels, and proceeded to see how much it’d take before flipping the protection circuit, blowing up, or current limiting. To my surprise, not once did it shut off, even though the temperature of the chassis rose to levels hot enough to burn your hand, nor did it shut off even when driven into clipping.
Outside of a dead short, you’re more likely to blow an amplifier section than experience fussiness with difficult loads from an onkyo avr.
If the receiver is shutting off at high volume, something somewhere is shorted out, or the unit is defective.
Those loudspeakers are low impedance(6 ohms) and low sensitivity(85dB @1W,1M)...
So U need a hefty amplifier to drive to a loud SPL...
Just my $0.02...
What OP really needs is a heftier speaker. Just throwing power at speakers that fail to deliver adequate volumes into a medium size room is a waste of time, and a good way to blow speakers.
It is hard to know what the problem is.
You may have a faulty receiver.
You may have a wiring error. You have in wall wiring and this wiring quite often has faults like damage from a nail. I always recommend that any wire in walls be run in conduit. I recommend you wire the speakers not using the in wall wiring and see if that solves the problem as a test. If that solves it the in wall wiring needs to be redone.
You are using very small speakers. Your receiver has quite enough power to easily damage those speakers. People buy pip squeak speakers like that and think they will get room filling sound out of them. You won't. They are for low to moderate levels. Speakers like that are easily over driven causing thermal damage to the voice coils. This results in shorting of turns lowering the impedance and sound output and causing amp shut down.
If you are after higher volume levels than you need speaker with bigger more robust drivers.
My hunch is that your most likely problem is either faulty/damaged speaker wiring or thermal damage to your speakers from over driving.
Agree 100%. Avr power is rarely the problem when trying to get dynamic, room filling sound.
I wouldn’t use small speakers with 4” drivers unless it’s for a nearfield setup, as in a small desktop/pc setup. Even for a small bedroom setup I wouldn’t go below a 5.25” driver. Additionally, an 85dB sensitivity at 2.8v is closer to 1.4w at 6 ohms.
OP didn’t state his listening distance, but let’s assume 10’ since this is a fairly typical seating distance in many living rooms. At 100w, that’s about 93dB at the mlp per speaker. It’s highly doubtful those speakers will handle 100w without major distortion, but for the sake of discussion... this means you’re going to be doing good to watch movies at -20dB down from reference levels on a good day with all of the stars aligned, wind blowing in the right direction etc.
Going to the physical limitations of the speakers, the -3dB point is around 80hz, it’s fair to assume the port tuning frequency is somewhere around here as well. Almost every 4” driver I’ve measured turns out to have a 3” or less radiating diameter when you exclude the surrounds and basket edge.
Watching movies at -20dB, or listening to music at 75-80dB with a 5-10dB crest factor, however unexciting this may be, will require a headroom of 95dB @1m to handle 85dB peaks at a 10’ distance.
@100hz and 95dB, you’re looking at 8mm of excursion. Even my subs driver only has about 9mm of xmax. Good luck getting that out of a 4” driver without the VC jumping the gap, leading to gross distortion, dynamic compression, and potential failure of the driver due to bottoming out.
This is ignoring the fact speakers are rated at 75w, and that this rating is likely exaggerated. It’s highly unlikely Micca would take the time and money to rigorously test those speakers with pink noise to derive this power handling spec, more than likely, this number was simply pulled from a hat.
I’d imagine the driver dips down to at least 4ohms, maybe lower, across the midbass/midrange region from 100hz-1khz, doubling the power requirement. Since most of the power from real content is heavily weighted in this region, you’ve now increased the power requirements to reach a measly 85dB @10’ to about 200w.
The reason I’m throwing all of these numbers out here is because I don’t think most people really grasp just how compromising small, inefficient speakers are when attempting to achieve even modest volumes in an average living room. As I frequently state around here, achieving realistic playback volumes with low distortion, and excellent dynamic range is a speaker problem, not a power problem.
My setups components were chosen to reach my desired playback volume (105dB per speaker, or film reference level) with a typical 100wpc AVR and an extra 3dB of headroom for safety. All three front speakers have an in room sensitivity of 96dB @ 2.83v/1m at a distance of 10 1/2’, I have absolutely no difficulty with playback of movies and music @ reference levels with no distortion or dynamic range compression, and I can do so even without the use of excessive bass management (ie an 80hz xover) to offload the low end from the speakers.
Always get the biggest, most efficient speakers you can afford. Especially for movies, which place very high demands on speakers.
In addition the surround speakers should be just as capable of keeping up with the front three speakers. It is a misnomer that surrounds can be of lesser quality, especially if you watch lots of action movies. I often wonder if people who are under the impression that surrounds are “barely used” arrived at this conclusion because their puny surround speakers are buried underneath their more capable fronts during scenes that call for lots of multichannel action.
You definitely need some bigger speakers. If budget is an issue (just assuming so based on your current speaker choices), a pair of Klipsch R-15m’s and an R-25c can be had on eBay as open box models for under $200, and considering their 94dB sensitivity, will do a much better job filling a room with sound. I had them in a 2000 cu ft living room for about a year, crossed over at 60hz, they didn’t have any difficulty handling moderately high volumes (~95dB) at a 10’ listening distance. If bright treble doesn’t bother you, the discontinued RB-51 IIs go for around $180 on Amazon, and will do an even better job.
