Sony 5300 runs hot - Protection kicking in

[bhelms]

The thread title sums it up. I love this new HT receiver/speakers in almost all regards but this one.

I do have a tendency to crank this thing up and lately I have found the limit on several occasions. It happened first when I was enjoying some of my new SACDs. Halfway through the second disk the whole system went completely silent without any warning, the display briefly said "Protection", then it went blank as well. The top on the unit was "egg-frying" hot. I let it cool about 1/2 hour, started cranking again, and within 2 mins. it happened again. After another 1/2 hour cool down I was running again, but at about 10 dB lower (per the inconsequential, relative read-out) than before. These are not ear-ringing levels either, like the front 10 rows at a concert. But they are considerably higher than I would have them with other folks in the room (certainly couldn't carry on a conversation!)

The other evening the thing went into protection again for the first time while I was watching a movie, again at a level I only use when I'm by myself. I believe the instantaneous power demand can be higher for movies in general, but the average is probably lower. I guess the average this time was also too high! In fairness, our weather has taken a turn for the 90s, so the ambient might have been as much as 10 deg. higher than in recent weeks since I got the system running in early May. I don't have air conditioning.

I won't absolutely guarantee it, but I can't believe this is related to any issues with the speakers or wiring since everything sounds great up to the apparent thermal shutdown point. The receiver is only powering 5 speakers. There is only a preamp out for the (self-powered) sub and I don't have any surround backs connected at this time. The Paradigms are nominally 8 ohms, and the receiver is set to match. I have them set for "small", channeling more LFE to the sub. I have the front crossover freqs. set at 80Hz, IIRC.

The receiver is on the top shelf of an open equipment rack and essentially in free air. There is almost nothing above it (my old R-R recorder is on top of it, but only over the front 1/3 of the receiver, and there is airflow between) and there is nothing below it that produces heat.

The evening the unit shut down playing a movie I placed a small 2-speed fan on the top of the receiver with the air blowing down into the receiver to cool it quicker following the shutdown, then I left it running on the lower speed for the duration of the movie. This seemed to give me a cushion - I got through the rest of that movie at only about 5dB lower indicated volume without further issue. Frequent "hand checks" on the top of the receiver proved it was running a good bit cooler, but that was not consistent over the whole top surface.

The next morning, while the ambient was still relatively cool I was playing a CD again, just started from a "cold start", and I had not turned the fan on yet. I was "up there" in volume again, maybe 5dB lower, and within the first song the unit cut out again!

Any suggestions? (Other than "turn it down"...that's no fun, and the darn thing sounds great at those levels!)

I was thinking of getting a pair of 4", 65 cfm, 120vac box fans to position side-by-side on the top on the receiver with the airflow being sucked into the botton and out through the top (reverse of what I have now with that single fan). I want at least 2 fans (there's probably room for 3) in order to spread the cooling over a wider area, over those "hot spots" I detected. For now I'll just run the fans with a switch. Eventually I'll come up with some kind of thermostat instead, perhaps multi-stage them at that time.

Is there anything else out there already that does the same kind of thing? I know about laptop coolers, but I don't think those would be anywhere near enough airflow for this situation, and most of the ones I know about need a USB port for their 5vdc power requirement, something the Sony does not have.

TIA for any advice, and BRgds...

 

[jayn_j]

A couple of things here. First, you mention the receiver, but not the speaker model. If you are using a low efficiency speaker, you will need to crank the volume up to get these high sound levels. You could just go for a higher efficiency speaker, although lower efficiency usually = cleaner sound.

I am afraid that if you keep hitting the protection circuit, you will eventually damage the unit. I have found that over time the protection kicks in at lower levels.

Obviously the cooling is an issue, but airflow alone may not solve it. It will help, but a fan across the top or down from the top won't help much. You need to increase airflow up through the unit with the hot air venting out the top. This may mean cutting vents into the side case, or simply turning the fans over so they suck out the top. What you really need is higher rated power transisters and/or better heatsinks.

 

[bhelms]

These of course are all new additions to my HT per my other thread in this forum, all the details are in there. You'll recall all the comments/suggestions you and others gave me in that quest. (Tks again for all that!) See post #18:

http://www.satelliteguys.us/v-recei...-ht-receiver-amp-speakers-recommendation.html

I have no idea how the Paradigms stack up to other options as far as efficiency goes. I'll try to do some web research there. But at this point I'm not about to reinvest in speakers. I know the 30+ y.o. stereo system these units replaced never had a similar problem, probably for a variety of reasons. My JBLs were notoriously inefficient. I once did a side-by-side comparison with Bose 901s and sadly the JBLs came in second in a number of categories particularly SPL at a given volume setting. But coupled with my 160w/ch Kenwood receiver, I could "rock the place" at even higher levels (never sustained for long) and that receiver barely even got warm. I don't think the Kenwood had a similar thermal protection system built in, but if it did I never triggered it!

The STR-DA5300ES is currently Sony's top-of-the-line receiver and is supposedly rated for 130w RMS per channel. I don't know if that's with all 6 channels driven at the same time or how it's measured however. I'm not about to replace that unit at this time, but some day I might try external amps. I also have the option to bi-amp the fronts using the currently unconnected SB amplifiers, but I don't see how that will help the overall thermal situation.

Seems to me that units are somehow "rated dufferently" these days vs. my ancient experience. For instance, this Sony reveiver is capable of delivering considerable output power to 7 channels simultaneously, yet it weighs probably only half what the Kenwood weighs that only powered 2 channels. To be sure, in the latter a good bit of that weight is the massive heatsinks. I can't even see heatsinks through the vents in the Sony! (The Kenwood was one of the first to use output ICs vs. discrete transistors, and the whole output stage was completely direct-coupled. The receiver also had dual power supplies. I once priced a replacement IC and it was well over $100, IIRC.)

I have plenty of volume with the Sony for most of my listening requirements, probably even without extra cooling. But since I have run into the limit, I want some added "protection from the protection", if you know what I mean! I completely hear/understand you re: damaging the unit by repeatedly hitting the protection level. And the fact that I am operating at that level means that I am pushing the amps in this receiver much closer to their limits which of course calls the whole distortion issue into question. I have not heard even a bit of distortion from the speakers however, which is one reason it's so cool to keep cranking it up! I was convinced that I consistently operated my Kenwood way below its limits, perhaps at 50% or less, even at the highest volumes I used. Of course in those days we never dealt with more than perhaps 50-60dB of dynamic range and music at a continuously loud level was painful! (I didn't hit an 80dB range until I got my first Hi-Fi VHS player. I never had any digital sources connected into that system.)

Back OT - I think I really need a fan system to help with the long term reliability of this receiver even if I don't push it to the current protection limit. Hopefully with fans I can get to that level that I want on rare occasions without protection kicking in. I have several means (thermocouple and remote IR) to take some experimental readings, perhaps even inside the case, so I could find an optimal solution with some science behind it. As mentioned before, I would probably use 2-3 fans spread over the top with the airflow up and out of the case. That's a non-invasive option that is relatively inexpensive and won't void my warranty by opening or modifying the unit. With some contortions I could instead put those fans on the bottom blowing in/up, but that will take much more effort.

I'll do something in the next week or so. Until then, it's "modest volume" only and the temporary fan on whenever the receiver is not in standby. I have plenty of other ways to "fry my eggs"...!

 

[jvc]

Did you double check your speaker wire connections, at both ends? One single strand of wire, touching the wrong thing, will cause this, at higher volumes. At lower volumes, it doesn't happen as quickly, but eventually probably will happen. This is USUALLY the reason a receiver goes into protect mode.

Also, if you're trying to drive 4 ohm speakers, with an 8 ohm receiver, this can happen. I'm not familiar with your Paradigm speakers, so I don't know if this is the case. Seems like the Sony, being their newest and best, should handle 4 ohm speakers, but you never know. Does it say in the owner's manual, what ohm speakers to use?

There's always the chance there's actually a problem. Have you contacted Sony about it?
Good luck!

 

[bhelms]

Tks, jvc. In fact I have (still!) not checked all the speaker connections. I'll definitely do that soon, maybe tonight, and report back. The Paradigms are spec'd as 8-ohms. The Sony has an easy-to-navigate GUI for all the set-ups including speakers. IIRC (need to re-confirm) I have all the speakers (except the sub, which is self-powered and not part of the Sony amplication) set to 8-ohms and "small" to channel most of the bass to the sub. All are crossed at 80Hz as well, so the extra power that would be used to amplify the lower frequencies should not be part of the "equation" as far as the receiver is concerned. The receiver will accommodate either 4- or 8-ohms. I was thinking about setting it at 4-ohms anyway; it might give the receiver some headroom that I don't have when it is matched at 8-ohms.

I have had a couple more weeks experience with the system since I started this thread. Since then the results have been about the same. I seem to be able to watch movies, even those with a lot of action/sound, at a relatively high level - as high as I'm likely to want it - without any problems. But when I play music, with its more consistent output at a similar volume level, the protection will kick-in within about 20 mins. For movies/music I have a small fan blowing down into the top vents, but it does not cover the whole area and also has a fairly low output. The top of the receiver remains rather cool/tepid as long as that fan is running, but it has "hotspots" where the fan is not blowing. When I just watch TV, almost always at lower volumes, there are no problems even if the fan is not running at the time, and the top of the receiver is relatively cool and no hot spots.

I ordered 3 box fans, 4.7" sq., 65 cfm flow ea., and also a fan control "close-on-rise" switch. I'll start by locating those fans across the top of the receiver near the front where the heatsink is (I found it, d'uhhh!) and sucking air through and blowing up/out. 3 fans will cover the whole width, but not the vents toward the rear. (I might cover those to make sure there is forced flow through the underlying components, and to be sure the air being sucked-out by the fans is entering from the bottom and not those rear top vents.) That should put some substantial cooling on the heatsinks, and hopefully assist the other components as well. The fan switch will serve as a thermostat. I'll place it on the top of the receiver and set it to kick in at 115 deg. F. It has a 25 deg. deadband, meaning that it won't kick off until the receiver reaches about 90 F, almost ambient. That probably won't happen until a bit after the receiver is turned-off, or reduced to a very modest volume. So in essence those fans will be running most of the time I'm "cranking", which is what I want. If this plan doesn't work, I'll relocate the fans to below the receiver. Here three fans will almost exactly match the bottom vents, 2 to the front and 1 toward the rear. This is probably the best configuration as the air flow would be more in the intended pattern. But this is a more involved project, requiring a means of raising the receiver about 2.5" off the shelf (making in higher than I want) or cutting-out the shelf to match the fans. That's a desirable, but irreversible, option.

I have not contacted my dealer or Sony yet, both things I should do. I wanted more substantive experience first. I'm also a bit worried about consequences with my warranty.

I'll report back as there are develpments.

Tks all for your interest and BRgds...

 

[bhelms]

Update 6/19/08

I confirmed all the speaker connections are good on both ends. I reset the receiver telling it that the connected speakers are 4-ohms vs. 8, confirmed the crossovers are all at 80Hz, backed-off on the added gain for the rears (they had seemed weak before) to just +2dB (was 4), and tweaked the EQs a little to de-emphasise the bass in all speakers (only +1dB now in all). To offset that bass loss in the main speakers I selected the +10dB sub. boost for the multi-channel (analog) input where my SACD player is connected and from which I derive all the music that has been the source when the protection-mode problems occur. These last 3 changes should in effect transfer some additional amount of bass reproduction to the sub amplifier and away from the receiver, hopefully with some associated reduction in heat production in the receiver. I didn't however get a chance to crank it last evening to see if the propensity for the protection to kick in was reduced. The only other change I would make in these settings would be to raise the crossover frequency higher, but I fear I will lose some of the imaging if I do so. (Any comments on that?)

One question - I like my audio "bright", thus I have always tended to set the mid- and high- range controls to emphasize the treble. Of course as I get older and my hearing acquity decreases, I have an even greater reason to do so! In my current set-up I have all 5 speakers set for +8dB boost at 10kHz. What added demand does that make on the amplification? I assume since that is just shifting the frequency content in the overall loudness that it would be a wash power-, and hence heat-wise. I.e., if I reduce the treble I am likely to increase the overall volume to maintain the same volume level, thus demanding the same power from the amps. Am I wrong on that ??

I received the fan control switch already! Less than 24-hours from time of order until it arrived on my doorstep from about 200 miles away. I didn't ask for express shipping, and only paid $4 for it. But that's service !! Now if I can just expedite the fans...!

More to come...

 

[jvc]

The only other change I would make in these settings would be to raise the crossover frequency higher, but I fear I will lose some of the imaging if I do so. (Any comments on that?)

All I can say is try it. If it doesn't work like you want, you can change it back. I still think it might be a good idea to contact Sony. It may be a known problem, that they can help with. If nothing else, you're letting them know early that there's a problem, in case warranty has to kick in, for a fix.
Good luck!

 

[bhelms]

UPDATE: Found the problem !!

It's called a dead short, or close to it, in one of the surround speakers! The tweeter was working fine, but the mid/bass driver was out almost completely. A DC resistance test measured ~6 ohms on the good surround 2-way cabinet and ~0.5 on the bad one! A battery "click" test on the bad speaker produced only a faint sound when connected momentarily directly to the mid/bass driver, but a solid "scratch" on the good speaker. I don't know how I didn't figure this out sooner just by the sound, or lack of! Duuhhh !!! Maybe because the tweeter still gave some presence from that corner and the mid frequencies are a bit less position-specific.

Anyway, I bought another matching set of the same speakers and replaced both in the surround position. Back in business! I left the receiver set at 4-ohms for now. I am now getting a clean, sustainable volume out of the system without any indication of overheating or protection imminent. The top of the unit gets warm, but not "egg-frying hot" as originally reported. Paradigm repaired the damaged speaker no charge. After I pick it up this week I will place that original pair in the surround back locations when I convert to a 7.1 configuration in the not-too-distant future. Then I'll be completely "BD ready".

I am relatively sure I blew that speaker without realizing it during my "0 dB crank" of Dark Side early in the new HT / SACD experience. Why I didn't realize that for about 2 weeks still escapes me, but that's what happened. There was no audible distortion that might have been a warning so I'm guessing it happened in a sudden spike of power. I admitted to the dealer that it may have been my fault, but apparently Paradigm honored the warranty without questioning the source of the damage. (I'm sure upon "autopsy" the overload was apparent!) A quick check of all the other speakers in the system revealed no other problems. Strange perhaps that I would only lose one driver, but perhaps lucky as well! Interesting too that the cone of the blown driver seemed to have full, unimpeded motion over its range. The only other time I had an experience with a blown speaker (guitar amp) that driver made a "scraping" sound as you tried to push it in; the coil wires had obviously overheated and blistered the insulation causing the interference.

So for now I'll keep the volume a bit lower...just a bit...and keep an "ear" on the sound and a hand on the receiver's lid. I still have fans on order to provide a reliable cooling source for the receiver but perhaps now it's a bit less urgent. Kudos to the Sony 5300 that survived the short with no apparent damage. But only time will tell the full story. (Glad it has a 2-year warranty...!)

EDIT: In post #3 above I postulated that receiver power ratings are somehow different than what I remember from 25 years ago. I found some corroboration! The Sony is rated at 120 W rms/channel (not 130 W I mentioned), but with all 7 channels driven simultaneously the actual is more like 65 W rms ea. max. I'm guessing this is a power supply issue as much as anything. (The unit is rated to draw only 450 watts max. from the mains. How could it be providing 7 x 120 W rms output ??) My Kenwood by comparison is rated at 160 W rms both channels driven. It has "dual power supplies" (tho' only a single - but massive - transformer...)

 

[jvc]

Glad you got it figured out.
Enjoy!

Paradigm probably feels the speaker should have held up under the load that was put on it, and they're probably right.

There's only a handful of Blu ray titles that are in 7.1, so you can enjoy BD now, instead of waiting until you configure for a 7.1 setup (unless there's more reasons than that, for waiting).

 

[jayn_j]

That says something for your receiver that it was able to drive that low impedence load at all. Mike's short just caused the protection to immediately kick in, and we caught that one right away.

Glad you found the problem. I'm also glad that Paradigm stepped up. Personally, I doubt you were running things past limits, because it would have sounded bad before you got to the point of failure. In addition, these loud level failures are almost always tweeters that get fried. I think this is a simple case of infant mortality that all manufacturers have to live with.

 

[bhelms]

Hope you're right on that! Maybe the fact that I went with 14 ga. wire vs. 12 ga. "helped" in this situation. Both surrounds have 50' of 14 ga. currently in the loop in anticipation of the final wiring scheme when I decide on a final placement. (I won't need as much - maybe 40' - to run to the surrounds when I go to 7.1, but then I'll use those 50' lengths for the SBs.)

I don't have a lot of experience with the Paradigms, but I find them rather crisp and clean and with no evidence of distortion even at the higher levels I occasionally enjoy, and yes - I do expect them to handle that level at least occasionally/intermittently. As mentioned above I never had any audible indication of any "distress" in a speaker leading up to the short (adding to my desire/enjoyment of the higher level) and hence the extended time it took me to discover the problem. Maybe Paradigm is giving me the benefit of the doubt, or perhaps maybe there was indeed an "infant mortality" in play! Either way, their service is great!

FWIW, in my experience the tweeter issue is more with high volume levels coming from underpowered amps, when clipped signals are more likely. But I could ALWAYS hear that kind of distortion well before any damage resulted. That's one reason I went with the 5300 - 120 w/ch vs 100 w/ch in the 4300 - to get the extra margin of safety from clipping. In the case of lower frequency speakers, I can hear other kinds of distress - like the voice coil form bottoming-out or unnatural "harshness" - in advance of permanent damage. I mentioned above the only time I ever actually damaged a voice coil due to overload, and that one was permanent.

Re: "BD ready" - I went so far as to add the HDMI cable and even name the input on the receiver in anticipation of getting a BD player at some point. But for now I'm strictly enjoying my rather extensive HD-DVD collection (dead indeed!) with both the A2 and A35 connected. (With 6 HDMI inputs, why not ?!?) And I'm getting some titles - some even with TrueHD audio tracks! - for as little as $6 ea. shipped. I won't pull the trigger on BD until Profile 2.0 is released and "affordable" ($250 - $300 ??), and hopefully the titles priced a little more reasonably as well. But that's a topic for another thread...!

Tks all for your comments and support. I might report back when I get the fans running...

 

[Skibum]

Glad to hear it's working out!

I've got a pair of Paradigm Studio 60's (little older), and they are NICE. They've been properly broken in by one of my good A/V buddies and I use external amplification for 'em. I'd put them up against any other speaker you can buy for under $3000, they sound that good.