Thermal shutdown

[johnnybravo1987]

Hey all. I have the Yamaha RXV1500. I've had very good luck with Yammy's and a lot of experience with them. However, I'm baffled by one singular problem: During the movie "Master & Commander", if I play to the volume I like I end up with thermal shutdown, even with the internal fan on max. Ok, so you would think, sure, play it loud enough for long enough and that will happen. BUT, it's the ONLY movie/music I've played on there to shut it down! And honestly, it's not terribly loud (I've played Blade II with some excrutiating volume and it was no problem). I've checked impedance settings, calibration settings, etc. I can add an external fan, but why just this one movie makes it so hot is nuts. Is it just because so much more surround info is going on? Thoughts?
Thanks!

 

[Seth=L]

Must be some low, low bass. Maybe try watching how the speaker cones are moving when it happens, higher exertions require larger amounts of power. In a few movies I have watched had some LFE's that are lower than human hearing and caused damage to my M&K sub, dead power supply. Just because you can't hear the demanding tones, doesn't mean they are not there.

 

[chas_w]

Do you have a sub? Are your speakers set to small or large? Setting them to small and crossing over the lower bass to a powered sub will take a lot of strain off the receiver.

 

[johnnybravo1987]

The speakers and settings

Hey all. Good points. First, I have Klipsch powered towers, so the bass is handled by the amp in the speaker's sub, so even though it's a pretty sensitive speaker, only the midrange and tweeter is powered through the receiver. Also, I have a stand-alone Velodyne sub (fed line level) with servo anti-clipping circuitry (which wouldn't matter for the receiver anyway). I run the mains set at Large, since it wouldn't make sense not to since they have their own subs. The center and rear are run at Small. The impedance is set to 8ohms, and everything i've read says to do that, and not at 6ohms.
I ran the YPAO program to balance the system, then ran test tones using my SPL meter to verify. So, I'm totally stumped........

 

[Snap]

I have the RX-V1600 in my showroom. I also play the DTS Demo Disc that has a clip from Master And Commander. I too have had the SAME problem. The only thing that kept mine from doing it, and I DO NOT KNOW WHY. But turn down the gain on the Sub. Granted it is now out of calibration, but the bass is still plenty loud for the ship battle scene. But when I watch that clip, I turn down the sub and it has not shut off yet.

Wierd though.

 

[AVRat]

Which Klipsch towers are you running? The receiver is sending the full powered, full range signal to the speakers when set to large which can put a heavy burden on the receiver, even though the woofers are powered. And on some movies which are bass heavy, there is a preponderance that goes to the front soundstage. A lot of the Klipsch towers have a crossover at around 2200 Hz which is a large range for the woofers to handle. Resetting the speakers to small with an 80 Hz X-over should alleviate the problem without a detriment to sound quality.

 

[johnnybravo1987]

Interesting

You bring up some good points. I'm running the RP-3's which have crossovers at 2750 and 90 Hz. I'm curious if I set the speakers to small, won't I lose a majority of the low frequencies to the mains? I guess the other thing is that it only happens on one movie, so maybe it's not worth worrying about, it's just that it boggles my mind that just one movie shuts it down. I'll have to look at the mixing of the DVD. I can't remember if I was playing DTS or DD soundtracks, but I thought it was THX mastered, in which case I think there's max levels that can be sent to each channel.
Also, it's my understanding that it might be detrimental to utilize the receiver's crossover directly to the mains. True? Something about running crossover's in series or something.
However, you do bring up a point I'll look at on the speakers themselves, that being the crossover setting on the back, although that still wouldn't affect the fact that the full range amplified signal is still being fed to it. Ugh. I might try the receiver's size setting just to see how it sounds...

 

[sivadselim]

A blown driver can make a receiver do this.

 

[johnnybravo1987]

Um, like that would really suck! I don't think that's the problem (I have experienced that before though with some super cheap ceiling speakers I used to get me by once), but I'll double check that tonite.

 

[AVRat]

You’re right about cascading X-overs. The only other option I can think of would be to run the tower’s woofers off of the sub pre-out as well as the sub. Getting a system like yours set up properly can be a PITA. Just out of curiosity, what are the channel levels set at?

 

[johnnybravo1987]

I'll have to check the levels when I get home. I assume you mean +/-dB from 0. From memory, the highest levels are only +1.5dB (the rear speakers are B&W in ceiling rounds), and I don't think that's too high. I like the idea of running the tower’s woofers off of the sub pre-out as well as the sub. I'll make sure to double check my other settings as well.
Oh, and you're right about it being a PITA!!