amp question

Discussion in 'AV Receivers' started by Frank joe, Sep 21, 2003.

  1. Frank joe

    Frank joe Stunt Coordinator

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    i posted this in wrong area before (audio video) .i am usuing a pioneer elite 39tx reciever. i bought a ati 2505 amp rated at 250 wtts pers channel to all five channels at same time. when i connnected it and turned volume up it seemd to be the dial was in same position as it was before amp was connected. like giving me same volume as before? i though t it would be much louder. i am usuing nht evoulation system . they can handle the power with no problem, buti have to really turn the volume up, even with the amp. i use to listen to the dial at -15 and i figured with the new amp i wouldnt even come close to that with all the new power, at least 2x what i had before? any idears why???????? frank
     
  2. Kevin. W

    Kevin. W Screenwriter

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    It takes a doubling of power(120w to 250w) to hear a 3db increase in sound. And 3db is not a very noticable difference. What you should/could hear is, better clairty, openess, improved soundstage and increased detail from your speakers. After hooking up your amp make sure you recalibrate then go back and listen to some of your favourite movies and CD's and see if you can hear a difference. I was in the same boat when I upgraded from my Rotel RMB-1066(5x70) to a Rotel RMB-1095(5x200). Though my increase in ouput was greater it was the overall sound quality coming from my speakers that I can hear. Also the top end was more well defined and didn't feel strained. What model of NHT speakers are you powering? I was looking at the NHT website and from what I can tell the Evolution speakers are very efficient(105db+). To be quite honest you have no need for an amp to power them. You'd be lucky to be using more than 16 watts per channel for most of your listening. Remember it takes 1watt at 1meter to produce the efficiency db of your speakers. SO if you have the NHT M5(efficiency of 105db)

    1w/1m : 105db
    2w/1m: 108db
    4w/1m: 111db
    etc etc

    So as you can see at 1w your already at Dolby Reference levels.

    Kevin

    Kevin
     
  3. Dave Milne

    Dave Milne Supporting Actor

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    Frank,
    It could very well be that the input sensitivity of the ATI is relatively low compared to the line-level outputs on your Pioneer. Thus, you would have to turn the volume control higher to get the same power output. This is perfectly normal. There's no "standard" for line-level. Some amplifiers require 0.25 vrms input for full power out... some require 3.0 vrms for full power. As long as you can drive the ATI to full power output before maxing out the volume control on the Pioneer, you're fine.
     
  4. Frank joe

    Frank joe Stunt Coordinator

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    the nht model is the b5 monitors when u couple them with the base bottom sub its called the t5. the b5 sit on top of the sub. the b5 require alot of power not only from the spec shhet but also fro nht themseleves. they recommend 200 watts or better , as there sensitivity if fairly low. they are also rated at 6 ohms . could it be that because i have the setting for them as small in stead fo large ???
    i guess i could set them to large and cut the frequincy off at 100 instead of 80 like i have now. also since i have now went with a seperate amp. i can no longer use the main out jacks to go to the nht crossover. i tried just usuing the sub out jack on the pioneer but it seems the only time i get information from it is in movie soundtracks. i get nothing when i just play cd of tuner. could i split the left and right signal outputs ( one going to my amp and other to nht crossover)? this would i think solve my problem. any idears will help. frank.
     
  5. Yogi

    Yogi Screenwriter

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    Setting speakers large sets the xover at 80Hz and small sets it to 100Hz. Also you can split the preouts without any problem. Also you dont have a problem if you have to set your volume dial to the same or even higher level from the receiver only setting. It only means the amp is not sensitive enough and as long as you have everything calibrated is shouldn't matter.

    Best of luck.
     

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