Too little power to receiver using one outlet?

Discussion in 'AV Receivers' started by David Ruggiero, Oct 9, 2003.

  1. David Ruggiero

    David Ruggiero Stunt Coordinator

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    Hello, I have a problem with my HK AVR-525 shutting off at loud volumes. It usually happens when there is an explosion in a movie or loud drums in music. Originally I thought it was overheating and it was shutting off to protect itself. However today, I decided to try a little experiment. The receiver was ice cold (been off all night) and I fired up Star Wars Episode 2. I turned the volume up to -15. In the begining when Senator Amidala's ship blows up my receiver shut off. It was still cold. So now I do not believe it is a heat related problem. However, I have my receiver, tv, dvd player, vcr, subwoofer, and cable box all plugged into the same cheap power strip. I am wondering if perhaps by using just one outlet for all my equipment, maybe it doesn't supply enough power to the receiver during really loud scenes for that split second and that causes it to turn off? Or would the house circuit breaker trip instead? Any advice/help would be apreciated.
     
  2. Jack Shappa

    Jack Shappa Second Unit

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    I think your breaker would be popping if the receiver pushed it over the edge. I think your receiver is going to grab all the juice it needs, either its more than the breaker can handle (pop) or it should work perfectly. Maybe your receiver is shutting down because its overloading your speakers.

    On a side note, someone correct me if I'm wrong but I think as long as the total needs of the equipment on a plug is under what the plug can handle it will all work at 100%. In other words, a receiver on a shared plug set at the same volume level is going to sound just as loud as one all by itself.

    - Cryo
     
  3. Chris A H

    Chris A H Stunt Coordinator

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    You could easily test this out. Plug everything but the H/K into a long extension cord and plug it into an outlet that runs off a different breaker. Try your loud volume test again and see what happens.
     
  4. Wayne A. Pflughaupt

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    David,

    The worst thing that would happen if there was so much plugged into an outlet that it “starved” a receiver would be a slight reduction in power (i.e., watts.)

    Typically there is only one explanation for a receiver shutting down during loud passages: It’s being driven too hard. The JBL’s are 8-ohm speakers, so they should be an easy load. However, your HK puts out only 70 watts per channel, which is on the low side.

    I’m guessing your listening area is fairly large, and as a result you have to crank the volume pretty hard to get realistic levels. Either that or you have the bass controls set high – this also increases power demands.

    You only have a few of options, the first being to turn the volume and/or bass down. If this is not palatable, you’ll have to look into getting more power – i.e., a more substantial receiver.

    Adding outboard power amps may be an option. The 525 has pre-outs for all channels, so try disconnecting some of the speakers – say, the front L/R pair or perhaps all three. If this solves the shutting down problem, then all you need to do is add a two- or three-channel amp for those channels.

    Regards,
    Wayne A. Pflughaupt
     
  5. David Ruggiero

    David Ruggiero Stunt Coordinator

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    Thanks for the replies. I did try plugging the receiver into different outlets today with an extension cord with the same results. So I know it is not the outlet.

    Wayne, if I am understanding your reply, if I add an addition amp for say the front speakers, I should be able to turn the receiver up higher without it shutting off as it would not be using as much power? This makes sense, but I don't understand why the receiver shuts off at -20, when the volume is capable of going to +10. It seems like there is a lot of "volume missing" for lack of a better term. Not to mention that this is a 7.1 receiver and I am only using 5.1 speakers. I guess it would shut off quicker if I actually used all 7.1 speakers.

    I wonder if anyone else has had this problem with the HK AVR-525. I still have the option of exchanging it for another from JandR.com. I want to stick with the HK AVR-525 though because I love the sound.
     
  6. ChrisLazarko

    ChrisLazarko Supporting Actor

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    One way you can make a definate test of wether there is really a problem somewhere here with the speakers is to just disconnect them, turn the volume up and play the movie. I noticed that when recievers shut off for people and I would try this it would usually either wield that the speakers were being driven to hard or the reciever had a malfunction...

    If it doesn't shut off when you try that it is probably your speakers, if it does call up HK and get a new reciever... they are usually good about that.
     
  7. Cary_H

    Cary_H Second Unit

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    No speakers, no load on receiver, no solution, IMO.
    Anyway, I'd think the receiver would have protection if it were run without speakers connected.

    How close are the speaker output terminals to each other on the back of your receiver? Bad connections, high loads, triggering protection?
    How about going back to a 2 speaker setup and systematically swap all the speakers in and out of the loop to find if, and which speaker if any, is the culprit?
    What about seeing if either speaker of each matching pair meter out the same resistance-wise?
     
  8. MikeTz

    MikeTz Stunt Coordinator

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    Dave:

    Your receiver is killing itself trying to service the speakers. One way out of this dilemma is to buy a powered subwoofer, set your speakers to small in the receiver set-up menu (bass information routed to the sub), and set the crossover frequency to 80Hz or higher. This will take a large load off your receiver and should make your system sound better. Since your JBL speaker's frequency response rolls of at 45Hz, the amp is trying to provide power at bass frequencies your speakers will not reproduce faithfully. The amplifier uses most of its energy reproducing bass frequencies. When the demand for bass power is great (in your movie test passage) the amp runs out of steam and cuts out.

    A powered sub and the correct speaker setting (small) in your reciver might alleviate this problem and provide you with more satisfying sound.

    Good Luck

    MT
     
  9. David Ruggiero

    David Ruggiero Stunt Coordinator

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    I do have a powered sub, and have my speakers set to small. I am going to try taking the crossover for the s-38's up to 100 and the s-center up to 120 to see if that makes a difference.

    Don't get me wrong I love the sound of this receiver, but it is a so called "high power" receiver, yet you can't play it all that loud.

    I guess I'll also try disconnecting each speaker one at a time and crank up the volume to see if there is any change. I wish I had some extra money, I'd try and swap it for a AVR-7200 if I could afford it. Maybe I'll exchange it for another AVR-525 and see if a new has the same problem. Heh, that would be my fourth AVR-525 if I do swap it...
     
  10. Jack Shappa

    Jack Shappa Second Unit

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    But at only 70 watts per channel, if your room isn't small, its not going to be able to fill it with "loudness". I've got a 110 watts/channel receiver in a moderate sized room and to fill the room with theatre-type sound I set it to about -12 (on a scale of -80 to +18)

    - Cryo
     
  11. Mike Allen

    Mike Allen Stunt Coordinator

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    I could very well be wrong, but this sounds like a problem with the receiver.....Unless(like stated above) you have a resistance problem in a speaker(s).

    That "70" watts is equal to most companies 100-120 watts. It shouldn't be shutting off like that when it's stone cold, especially if you have your speakers set to small and a powered sub.
    Mike Allen
     
  12. Tom Grooms

    Tom Grooms Second Unit

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  13. Kris_M

    Kris_M Auditioning

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    I had the same prob with a HK 520. It is a known defect with some HK's. But my problem was solved by checking speaker connections. Disconnect front and crank rears only.Disconect rears and crank center only......and so forth. In the end one woofer on my center channel was shorting out at high volumes only (like yours -15) It sounded normal during calibration so at first I thought the reciever was defective. I got the speaker fixed and problem solved. Thats my story for what its worth.

    Kris
     
  14. Aaron Gilbert

    Aaron Gilbert Second Unit

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    Tom,

    What's the theory behind never playing your receiver without speakers connected? That's a new one on me, and I've been in the hobby over 15 years. What could an open circuit on the output possibly damage?

    Last time I checked, receivers (or amplifiers) had all kinds of protection, from thermal overload, short circuited load, DC being sent through the load, even distortion limiting. I've run the volume up on plenty of receivers with no load, none have blown up yet. [​IMG] How is it any different than switching your A and B speakers off and listening to headphones?


    Aaron Gilbert
     
  15. Mike Allen

    Mike Allen Stunt Coordinator

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    Tom,
    Sorry if I was unclear. What I mean, is H/K underrates their amplifiers. And most other companies OVERrate their amplifiers. So my point is, while the H/K 525 is only rated at 70 watts, it most likely puts out around 80 watts. And while....(let's say) a Pioneer may be rated at 100 watts, it will probably only put out around 70-80 watts. I'm not saying it's true in all cases, but it is in MOST cases [​IMG]
    Mike Allen
     
  16. David Ruggiero

    David Ruggiero Stunt Coordinator

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    Well, I set my crossover on my front and surrounds up to 100 (from 60) and took my center up to 120 (from 80) and it has seemed to help. Last night I was able to play the Matrix lobby/helicopter scene and Star Wars Episode 2 up to -15 on the volume without it shutting off. I'd like to thank MikeTz for this suggestion, and also everyone else who responded to try and help me. I appreciate it.
     
  17. JohnSer

    JohnSer Stunt Coordinator

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    David,

    IMHO, you should not have to cross that high. The 525 should easily handle 5 - 8ohm speakers, @ 80Hz crossover, @ -15db setting. I have run less efficient speakers @ -15, large 60Hz, on a 520, with no issue. I suggest doing as Chris suggests, and also make sure you have no speaker wire strands sticking out anywhere. If receiver is still shutting down, consult HK about needing a repair. The HK FAQ says their units can handle most 4 ohm speakers, I would expect it to handle 8 ohms, especially ones made by one of its partner companies.

    JohnS
     

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