Amps and Heat

Discussion in 'Archived Threads 2001-2004' started by Aaron Cooke, Jul 13, 2002.

  1. Aaron Cooke

    Aaron Cooke Second Unit

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    I've got a B&K 7270 amp running 4 channels (2 mains, 2 surrounds don't have a center speaker yet). I was watching the NIN live DVD today at extremely high volumes, the highest i've used since getting the amp a few months ago. after a little while it seemed like i smelled something burning and checking the amp i discovered that it was extremely hot...to hot to touch. Currently I have it in a entertainment center with the front and back open and about 8 inches of clearance above the amp, but enclosed on the sides. I have been thinking about getting a rack from studiotech which would open the sides, but i think only leave a few inches clearance at most above the amp. So my first question is do you think the open sided rack would help dissapate heat better than having more cleance above? And secondly...is there something wrong with my system? Should i not be playing it this loudly? I believe it's calibrated to around reference and i'm using an Onkyo TX-SV828 as a pre/pro. I was listening around 3-6 db over reference. Just hoping to get some info on whether i need better ventilation, if there's a problem with my setup, or if i'm just insane for wanting to listen to it so loudly in the first place.

    Thanks for any help.
     
  2. Frank_S

    Frank_S Supporting Actor

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    Aaron, B&K's run hot so I highly recommend an open sided rack. You also need about 6" minimum clearance above. Check your owners manual for their recommended clearance.
     
  3. Al B. C

    Al B. C Supporting Actor

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    Heat! Never a problem with my Sunfire. My ears could be bleeding from the volume and that baby stays cool as a cucumber. [​IMG]
     
  4. Greg Haynes

    Greg Haynes Supporting Actor

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    A new rack could help, but the cheapest way would be to add a PC fan and have it pull the air out for you. You can do a search here on fans and most will tell you all you need to do is if you don't already have a fan is goto Radioshack to buy the fan and ac adaptor. Then plug the adaptor into your receiver so whenever your listening to music or movies your amp will be cool.
     
  5. Aaron Cooke

    Aaron Cooke Second Unit

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    Thanks for the advice so far everyone. I will add a fan, but i was planning on getting a new rack anyway. My problem is that the amp itself is about 7" tall...if i need 6 inches clearance above that would be a 13" bottom shelf. Can anyone reccommend any racks with that size bottom shelf. I'm looking to spend about $300 on a 4 shelf rack, preferably modular but would be willing to consider a $400 5 shelf one non-modular.
     
  6. Greg Haynes

    Greg Haynes Supporting Actor

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    www.audioadvisor.com seems to have the best racks. They have alot to choose from and pretty good prices. They have six shelf rack made by Sanus that I have been eyeing. They even have amp racks that you could put your amp on and separate it with the rest of your equipment. Then it would it have complete open space. Only do this if you have no kids or pets.
     
  7. Aaron Cooke

    Aaron Cooke Second Unit

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    I've got bigger problems now...I posted this in another thread having to do with amp clipping, but i noticed the titled was about Denon receivers so i thought i'd copy it here too....Help!


     
  8. Jeff Kohn

    Jeff Kohn Supporting Actor

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  9. Jason Bell

    Jason Bell Stunt Coordinator

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    Sorry about your speakers. I think with an amp that was that powerful you probably werent clipping. You probably got an instantaneous peak that sent to much power through the midrange drivers. For instance my speakers are rated at 250w but that rating is just what they can take for very short amounts of time. I also believe that most nicer amps have a lot of headroom and can go quite a bit over their rated power for brief dynamic periods in the music. You probably werent pushing the midranges to their excursion limits but were putting enough power to them that the voice coils couldnt cool themselves fast enough so they burnt out. If you do sell them you should replace the midranges it might not really cost that much and I'm sure you would end up getting more that way even after the replacement drivers. How loud were you listening? Good Luck.
     
  10. Aaron Cooke

    Aaron Cooke Second Unit

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    Jason, That sounds like exactly what happened. So how will I know in the future how loud I am able to play it before that will happen? Will different types of speakers be more or less prone to it happening? I've been leaning towards some sort of B&W (like the CDM 9NT or Nautilus 805 or even 804's) but if they are going to have the same problem when i try and crank it up maybe i'll just go with something super efficient like Klipsch.

    I use an onkyo receiver as a pre/pro and i believe it was calibrated to reference at 0db, and today i was playing it at between +4 and +6 db.

    Yeah, I think i'll probably try and replace the drivers and sell them for speaker upgrades. Guess Outlaw will get my money after all...I'd decided to go for broke with an Anthem AVM-20 but if i buy new speakers the Outlaw 950 will be more in my budget.

    Thanks for all the advice.
     
  11. Jason Bell

    Jason Bell Stunt Coordinator

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    Hi Aaron,
    I wouldnt be comfortable recommending new speakers for you. But if your current ones wont go as loud as you want and your amplification isnt your limit then more efficient speakers might be what you need. Not sure which ones though. All of this is assuming that my theory of what happened to your speakers is right.[​IMG] I was just throwing out suggestions of what I thought it might be. Can you call the manufacturer of your speakers and see what they think may have happened? They would no what there speakers can handle better than me. Good Luck.
    P.S. You like your music really loud I'm scared of +4 over reference?[​IMG]
     
  12. Greg Haynes

    Greg Haynes Supporting Actor

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    Hey Aaron, how long do you listen to your music at +4? And do you have anybody else living with you when listening at that level? Because that's pretty loud [​IMG]
     
  13. Brian Vaughan

    Brian Vaughan Stunt Coordinator

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    Hi Aaron. I've been running a B&K 7250 with five B&W speakers (804 mains, htm2 center, SCM surrounds) and I've had absolutely no problem driving them to insanely loud levels, so I wouldn't worry about the B&K not being able to handle the Nautilus line if you are interested in them. In fact, I just added a PS Audio HCA-2 for the mains in order to get better 2-channel music playback, and it is rated at 150 watts/channel (50 watts less than the B&K) and I have had no power problems at all.

    Cheers, Brian
     
  14. Aslam Imran

    Aslam Imran Second Unit

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  15. Aaron Cooke

    Aaron Cooke Second Unit

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    I'm not 100% sure I had everything properly calibrated to reference levels but I think it was at least pretty close. And yes, i was the only one home and had been watching a live Nine Inch Nails concert DVD for about 20 mins. and was basically trying to simulate the actual concert experience. I never listen that loud to 2 channel stereo for "critical" listening.

    Does anyone know if I can order replacement drivers directly from Def. Tech?

    Aaron
     
  16. Eric T

    Eric T Second Unit

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    You're right Aslam, I think the apparent volume will vary a lot depending on the room size and acoustics. I have a fairly well-damped room (carpet & two sofas, opens to another room on one side) that's maybe 20x16x10, and anything close to reference level just knocks me out of my chair [​IMG]
     

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