HELP! I think my receiever (SONY STR-DE725) killed 3 of my Paradigm speakers!

Discussion in 'Archived Threads 2001-2004' started by james e m, Feb 23, 2002.

  1. james e m

    james e m Second Unit

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    I just got a whole complete Paradigm speaker set up and about a month later my center channel started to break up with dialogue. I took it back to the dealer and we tested it and sure enough it started crackling when we played the midrange frequencies from a test cd. He exchanged the speaker and I thought the problem was solved. But I went to calibrate my speaker with Avia with an SPL meter and I noticed the same crackling with my Mini Monitors that I use for surround!!!! Does anybody know why this is happening? My only theory is that my cheap receiver isn't powerful enough and it's doing the damage.

    Here are the specs for my receiver:

    SONY RECEIVER STR-DE725

    Built-in Dolby (AC3) Digital Decoder

    Digital Cinema Sound Virtual 3D Modes

    Stereo Mode: 100 watts per channel x2, 8 ohms

    or 4 ohms, 20 - 20,000 Hz, 0.09% THD

    Digital Cinema Sound with 3 Cinema Studio

    Modes

    Surround Mode: 100 watts per channel x5, 8

    ohms, 1,000 Hz, 0.8% THD

    S-Link Control Bus for A/V System Convenience

    4 Audio Inputs/1 Audio Out

    4 Video Inputs/3 Video Out

    1 Optical Input/Output

    Two Subwoofer Outputs

    Does anybody know what is ruining my speakers? I have 2 surge protectors so I don't think it's that. ANY ADVICE WOULD BE GREATLY APPRECIATED!!!!

    james

    ps I have run some tests and I know for sure that there is now something wrong with the speakers, I just don't know what caused it.
     
  2. Paul_Fisher

    Paul_Fisher Screenwriter

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    I have a Kenwood receiver which only puts out 50W x 5 and I have mini-monitors as fronts and I've never had any problems with crackling.
     
  3. Thomas_Berg

    Thomas_Berg Screenwriter

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    your Sony DE model receiver is REALLY overrated power-wise. i doubt it actually puts out more than ~35 wpc when all channels are driven. it doesn't have nearly enough juice for the Paradigms. the Kenwood is cutting it close too. get something from Onkyo, Denon, Yamaha, or H/K for good results.
     
  4. james e m

    james e m Second Unit

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    Thanks you guys are confirming my suspicions. I just want Sony to pay me for the damage they have done with their false advertising! I just can't believe how fast my speakers were damaged, I don't know what to do. I spent ALL of my money on these new speakers and I was planning on buying the Onkyo 898 in October. Now I don't know what to do.

    James
     
  5. Tony Granatelli

    Tony Granatelli Stunt Coordinator

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    Well, I just purchased the Onkyo 898 but I haven't completley hooked it up yet...I'm an confident the Onkyo will have the power you need.
    The problem with low wattage AV units is you need to crank up the volume to get to a decent listening level... then, the distortion kills the speakers!
    This is also very common in car stereo systems....
     
  6. John Royster

    John Royster Screenwriter

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  7. Ron Shaw

    Ron Shaw Stunt Coordinator

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    I agree. You blew your speakers (most likely the tweeters). Sony isnt going to pay for it either (not unless you let them handle the volume control).
     
  8. Steve Berger

    Steve Berger Supporting Actor

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    I don't have a service manual at home but I believe the 725 has some limits on speaker impedence stated in obscure language on the back of the unit. In general the center and surrounds must be 8 ohms but if you use 4 ohm mains you cannot turn on surround or center channels at all.I'm not familiar with the specs on your speakers but an "8 ohm compatible" speaker is a 6 ohm speaker and must be set up as a 4 ohm speaker (with 4 ohm limits) on this amp. On the other hand the speakers must be rated at 100 watts RMS. A 100 watt "peak power" speaker will fry quickly since it is actually a 20-25 watt RMS speaker.I had a customer with a brand new set of speakers advertised as "designed for amplifiers from 20 to 100 watts". The first time he turned the volume up the voice coils melted. Before he took them back we popped the woofer out and saw "20 watts" printed on the magnet.
     
  9. Ed O

    Ed O Agent

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    Does speaker efficiency affect this by taxing an amp less if the speaker efficiency is higher (I wouldn't need to turn up the volume as much on the receiver with more efficient speakers to produce the same volume from less efficient speakers)? Or am I off base here and the only important specs are the ohms in this case?

    What would happen if there is a switch on the back of the receiver selecting the ohms reading on the speakers you are using?
     

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