my new receiver is on the way!!! (couple ??s)

Discussion in 'AV Receivers' started by JesseBro, Aug 17, 2003.

  1. JesseBro

    JesseBro Stunt Coordinator

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    i just won an auction on ebay for a Technics SA-AX7 receiver. i was looking for a loooooww budget receiver to get started in home theater and couldnt pass up this deal. i got it new for $103 shipped from emartdepot. anyway, im wondering how this receiver stacks up to lower end Onkyo, Denon, and Yamaha receivers since this is a higher end panasonic/technics receiver. im also wondering if it will be suitable for the B&W and Paradigm speakers i have been auditioning. i am not purchasing speakers for a little while until i am 100% certain on which i want. right now i have Vidsonix mini tower speakers up front and they will be moved to the rear when i decide on front speakers. im just looking for some info, advice, or suggestions. i havent even given thought to my center channel yet.

    specs on the receiver:
    crutchfield.com/cgi-bin/S-vrYnbxLximV/ProdView.asp?i=133SFDX7&s=0

    here are specs for the speakers:
    vidsonix.com/vidsonixnew/info_mgs84.htm
     
  2. RobWil

    RobWil Supporting Actor

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    Well notice that they give the power into 6 ohms vs 8 ohms
    "100 watts x 2 (stereo) into 6 ohms (20-20,000 Hz) at 0.05% THD" so it's probably more like 80wpc x 2 into 8 ohms.
    Those Videosonix don't look very demanding...it doesn't give recommended amplifier power but they're only rated at 110W peak power so the receiver will definitely handle those.
    I'm not too sure about the B&W or Paradigm's though. You better check first though as I think I've heard they like plenty of power.
    I'd say this receiver is a step below the lower-end brands you mentioned, but you certainly can't fault the price, and I'm sure it's a fine place to start. Hope you like it!
     
  3. Wayne Ernst

    Wayne Ernst Cinematographer

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    I'm a bit worried about your purchase of the Technics receiver. The Crutchfield page talks about a separate Dolby Digital and DTS converter (SH-AC500). Did you get this item along with the receiver? If not, you are going to have problems with watching DTS and DD sources while using that receiver.

    Plus, I should add that at $103, just about $50 more would have allowed you to get a newer receiver with the decoders built in.
     
  4. JesseBro

    JesseBro Stunt Coordinator

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    i have a hitachi DVD with the decoder built-in.... thats why i went this route. as far as the ohms are concerned, does 8 ohms produce better sound?? im not sure i understand why 100watts isnt 100 watts regardless of the ohms

    thanks for info.... keep it coming
     
  5. JackS

    JackS Supporting Actor

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    Jesse- I could be wrong, but the decoder in your DVDP may still not allow for DD/DTS. If your receiver is designed to accept these formats, you may be okey. MY thinking is that the decoder mentioned above that is designed to interface with the receiver comes "after" the receiver and then outputted to the speakers. If this turns out to be the case, you may be obliged to purchase an outboard decoder anyway. The good news might be that there were several made years ago so, finding a used one cheap should be a good possibility.
     
  6. JesseBro

    JesseBro Stunt Coordinator

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    it has a DTS output.... so couldnt i run the DTS sound line out to my receiver???
     
  7. Adam_Reiter

    Adam_Reiter Second Unit

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    Jesse, I will try not to screw this up, someone will have to chime in.

    Ohms has to do with resistance. Home speakers are usually rated at 8 ohms. This is the resistance value it offers the reciever.

    For instance, Cerwin Vega speakers, are usually 4 ohms. They offer a lower resistance to the reciever, and therefore givin twice or a third more power.

    For example, my amp pushes 200 watts per channel into 8 ohms, but, it pushes 300 watts per channel into 4 ohms. I have 4 ohm and 6 ohm speakers. So my 6 ohm speakers are getting about 250wpc.

    However, the lower the ohms/resistance, the more dangerous for your reveiver. For instance, you wouldnt want to go hooking up a 2 ohm speaker (usually subs) to your reciever. You could blow it up. The reciever needs more resistance than 2 ohms. You might even get into trouble with 4ohm speakers. Be sure to check an online manual.

    Also, just becuase it says DTS output, only means it passes the DTS info to the DTS decoder (usually in the reciever). I think only high end DVD players actually "decode" the DTS from the DVD player. For instance, my new $1000 Denon 2900 actually has built in DTS decoding. Again, you have to consult on online pdf manual to really make sure.

    What model DVD player do you own?
     
  8. JesseBro

    JesseBro Stunt Coordinator

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    its a Hitachi DV-P303 ... i dont have any books on it anymore

    thanks for the info on Ohms, i think i understand
     
  9. JimPeitersen

    JimPeitersen Second Unit

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    I believe Wayne is correct. This is one of the later Technics models designed to partner with the SH-AC500/SH-AC300 DD/DTS decoders (after this model all the Technics/Panasonic receivers had the processors built-in. If my memory serves me right the model you bought is a six-channel receiver (unusual in that it had a seperate channel for a passive sub).

    JackS,
    The SH-AC500 accepts coaxial/toslink DD/DTS signal from the DVD, and outputs 6 analog channels to the receiver/amp array, which drive the speakers.

    JP
     
  10. David_Stein

    David_Stein Second Unit

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    i can give a more technical answer about ohms.

    there are 4 basic concepts that are used when talking about powering speakers:
    1) Voltage
    2) Resistance/Impedence
    3) Current
    4) Power

    Power is the rating you see for amps/recievers usually. But its not just one measured value. Power is defined as an equation: Power = Voltage*Current. To make things a little more complex, there is another equation relating resistence/impedence, voltage, and current. Voltage = Current*Resistence. Using that equation you can form another equation for the power: Power = Voltage*Voltage/Resistance.

    This equation gives you the basic relation between the resistance of the speakers you are driving and the power the reciever is able to put out.

    unfortunately, that isnt all of the story either. Ill try to keep it as nontechnical as possible, but voltage is really just a potential, all its saying is that there is a difference in the amount of charge between the two terminals of your speaker (+ and -) and that this difference makes the electron (basic unit of of electrical energy in speakers for our purposes) want to move from one side to the other to even out the charge difference.

    now if you add something in between the two terminals that allows the electrons to flow from one terminal to another (like a speaker), you get a current. That current is dictated by the equation above (voltage = resistance*current). so just in general, if you lower the resistance of the speaker, then the speaker needs more current from the amp.


    all of the above im fairly sure of, what is below this line is how i think things works, but i am not sure and if someone can clarify one way or another I'd appreciate it.

    the circuitry in amps can only supply so much current. Its this current limit that dictates the the power rating of any given amplifier (whether its a stand alone or inside a reciever).

    i think that providing a voltage is not a tough thing for any amp, which means they can basically provide any voltage to a speaker so long as the current (Current = Voltage/Resistance) does not exceed the max current that the amplifier is able to provide. This is why you see recievers touting their "high current amplifiers". its debatable whether or not they qualify as high current amps, but saying you have an amp capable of "high current" (whatever that entails) is a good marketing point.
     
  11. RobWil

    RobWil Supporting Actor

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    Jesse...in simple terms it's the resistance that the amplifier is dealing with that determines the power that amp will provide. A 6-ohm speaker provides less resistance so the amp will be able to provide more power to it. An 8-ohm speaker provides more resistance so the same amp won't be able to supply as much power to it. Most amps state their power ratings into an 8-ohm resistance. Some manufacturers 'cheat' a little to make their power ratings seem higher by stating power into a 6-ohm resistance. Even the higher-end brands do this on their lowest end receivers so that the consumer looking at this price range won't think they are less powerful than the competitors.
     
  12. JesseBro

    JesseBro Stunt Coordinator

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    wow! thanks for all the info.... i have a very good understanding of it all now

    JimPeitersen-- are you saying that my DVD will work with my receiver then??? b/c im still thinking it will..... it was designed to accept the DTS output of the DVD. or is it designed in that if the DVD had an actual DTS processor built in than it would work without the seperate decoder that was sold to go with it
     
  13. JimPeitersen

    JimPeitersen Second Unit

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    Jesse,
    It may accept the DD/DTS output from the DVD player (you might have to manually select between them on the menu screen.) I'm not familiar with your DVD player, or using one as a decoder. Your set-up may work perfectly if the receiver amplifies the decoded signal (your DVD player is then in essence a pre-pro.) Let us know how it works.
    JP
     
  14. JesseBro

    JesseBro Stunt Coordinator

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    well it should be here tomorrow or thursday, so ill let you know what happens


    thanks again
     
  15. george.Legeza

    george.Legeza Stunt Coordinator

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    If your DVD player has build-in decoders and outputs along 6 analog channels and your receiver has 6 channel inputs I don't see why they wouldn't work together.
     
  16. JesseBro

    JesseBro Stunt Coordinator

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    my DVD says "DTS digital out" on the front of it and has these connections in back

    imagestation.com/picture/sraid75/pc14595232d2e561cc9ec6df15635f614/fb57a3dc.jpg

    (i cant post urls yet so you have to copy and paste)
    my receiver has these connections:

    akamaipix.crutchfield.com/products/2000/133/x133sfdx7-b.jpeg
     
  17. JesseBro

    JesseBro Stunt Coordinator

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    just wondering if anyone had any ideas whether this will work or not based on the pictures...... take a look
     
  18. Wayne Ernst

    Wayne Ernst Cinematographer

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    Jesse,

    Hmmm ... I took a look at your pictures. From what I see, it looks like your DVD will output the signal to the receiver. But, the signal would be decoded into DD or DTS by the receiver. However, your receiver will not do the decoding without the additional decoder. The signal going to the receiver via the digital coax cable still needs to be decoded. That is a feeling that I have.
     
  19. Jed M

    Jed M Cinematographer

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    Jesse, Wayne is right. In your case, you need an output for every channel (6 in all, cen, lf, rf, lr, rr, and sub) on the back of your dvd player if you want it to do the decoding, but only DD, not DTS (for the majority of players). They look like the the 5.1 outputs on this dvd player: http://www.crutchfield.com/cgi-bin/S...=XL#morephotos

    If the receiver was going to do the decoding a simple digital cable would take care of it, but since the decoding is left to the dvd player you need 6 analog outputs. Sorry if that seems confusing, but it is the same principle as SACD and DVD-A. I would look for a decoder or unfortunately try to sell your receiver on ebay and start again.
     
  20. JesseBro

    JesseBro Stunt Coordinator

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    i was looking to eventually get an SACD and DVD-A player...... whats the price range on one of those, maybe i could go that route
     

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