Poida Posted September 24, 2009 Share Posted September 24, 2009 (edited) I'm currently building a new house and as a part of it I am building a home theater with it. Everything is going to be brand new. I will be running Polk RTI series speakers as 7 channels however I am not sure as to what amp I should use. I would like to get an amp that can do around 250 a channel at 8 ohms, but more receivers cant do this so therefore im looking in to a pre/power setup, something like the Rotel 15 series? Im just trying to get ideas as to what I can do? I would like to keep it under 5k however I am more concerned with getting the 250 a channel at the moment. Edited October 1, 2009 by Poida Link to comment Share on other sites More sharing options...
Nick69 Posted September 24, 2009 Share Posted September 24, 2009 (edited) from what i've seen you will be hard pressed to get anything that can do 7x250 + a pre/pro for under 5k unless you can find something awesome for 2nd hand. Edited September 24, 2009 by Nick69 Link to comment Share on other sites More sharing options...
Poida Posted September 24, 2009 Author Share Posted September 24, 2009 it doesnt have to be under 5k, and just looking to power towers and center to start off with. Like with the rotel 15 series I think i can get a pre amp and 5 channel power amp for just over 5k, i think the 15 series 5 channel power amp runs just over 200w a channel, doesnt have to be 250w's just around that. Another thing, will it matter so much as to how much power i give the the Polk RSI A9 towers? there specs say there power range is 50 - 500w, to me that seems a bit suss? Link to comment Share on other sites More sharing options...
Antripodean Posted September 25, 2009 Share Posted September 25, 2009 Hi Poida I would suggest you go with the Elektra Theatron for your amp. They sound great and they are definitely capable of delivering the power you require, being underquoted from what I hear. I was thinking of this supplier in VIC so the price is in your budget. Link to comment Share on other sites More sharing options...
Mika75 Posted September 25, 2009 Share Posted September 25, 2009 One would have to ask, do u actually need 250watts per channel ? If so then Professional Studio Amplifiers are the way to go, such as the Yamaha P3500S, 2x 390watts for $850.00 http://www.soundcorp.com.au/store/?producttitle=Yamaha_P3500S&productcategoryid=64&productid=225 Link to comment Share on other sites More sharing options...
bluedog Posted September 25, 2009 Share Posted September 25, 2009 you could go with a denon 4308 and bi amp the fronts would give you around 280 watts per front speaker nice features too :-) Link to comment Share on other sites More sharing options...
norpus Posted September 26, 2009 Share Posted September 26, 2009 (edited) Hi PoidaI would suggest you go with the Elektra Theatron for your amp. They sound great and they are definitely capable of delivering the power you require, being underquoted from what I hear. I was thinking of this supplier in VIC so the price is in your budget. Agreed, great amp for 2 ch and 7. How the hell are they getting advertised for $2599 now!! Bargain of the century for a bricks and mortar shop. I wondered if those Group Buys would kill the market price for Arthur - still, volume up means lower prices to the punters so I guess it is a good thing afterall Poida, I own one of these and doubt whether I will ever sell it. It will do your HT needs easily and cleanly. It has a real 1.8kVa to back it up (1800/7 = 257) Match this with something like a Denon 4308 and you'll be set for your HT Edited September 26, 2009 by norpus Link to comment Share on other sites More sharing options...
Poida Posted September 30, 2009 Author Share Posted September 30, 2009 so do the polk RTI a9's need that much power? I know there ratings say 50 - 500watts, but thats a big difference. Link to comment Share on other sites More sharing options...
davewantsmoore Posted October 1, 2009 Share Posted October 1, 2009 They are 90db sensitivity. 50w will probably be fine. Link to comment Share on other sites More sharing options...
Poida Posted October 1, 2009 Author Share Posted October 1, 2009 They are 90db sensitivity. 50w will probably be fine. So its only when getting in to the low end that I would need more power? to get my mid range out of it I should be looking for around 150-200w? and if I want the deep bass I should go anywhere higher then 200w? Link to comment Share on other sites More sharing options...
davewantsmoore Posted October 1, 2009 Share Posted October 1, 2009 So its only when getting in to the low end that I would need more power? to get my mid range out of it I should be looking for around 150-200w? and if I want the deep bass I should go anywhere higher then 200w? no... a speaker with 90db sensitivity/efficiency will play quite loud on say 100w. Giving them "more power" won't make them sound better. Although the catch 22 is that buying a amp with more watts will (depending) buy you an amp higher up in a product range therefore of better quality. 'Power' is not really the issue. From what you are saying above, you sound a bit confused. Link to comment Share on other sites More sharing options...
Poida Posted October 1, 2009 Author Share Posted October 1, 2009 (edited) no... a speaker with 90db sensitivity/efficiency will play quite loud on say 100w. Giving them "more power" won't make them sound better.Although the catch 22 is that buying a amp with more watts will (depending) buy you an amp higher up in a product range therefore of better quality. 'Power' is not really the issue. From what you are saying above, you sound a bit confused. I'm more then a bit confused, so many numbers Basically I really like the polk speakers and I love mid range sounds, now the specs say 50-500w, I want to know how to get the maximum loudness out of the speakers without loosing too much quality. Now why would they say 50-500w? thats such a huge range. So your just saying that pretty much any higher end A/V Receiver will do the trick? Like a Denon 4308 or a Yamaha Z7? and I dont really need to go for power amps? If so, whats the point of power amps at all? why would you need more power for a Home Theater? Also Ive noticed most receivers dont get the frequency response that the A9s can handle. Edited October 1, 2009 by Poida Link to comment Share on other sites More sharing options...
Mika75 Posted October 1, 2009 Share Posted October 1, 2009 Also Ive noticed most receivers dont get the frequency response that the A9s can handle. Link to comment Share on other sites More sharing options...
Poida Posted October 1, 2009 Author Share Posted October 1, 2009 correct me if im wrong or I am misunderstanding something but most receivers say they get around 140w/channel at 20Hz - 20kHz, the Polk RTiA9's say there response is between 18Hz- 27kHz. Sorry didnt realise I didnt say exactly what speaker it was Link to comment Share on other sites More sharing options...
davewantsmoore Posted October 1, 2009 Share Posted October 1, 2009 Now why would they say 50-500w? thats such a huge range. w is a very inconclusive measurement when dealing with amplifiers.... it needs to be realated to a lot of things, primarily the sensitivity of the speakers, when thinking about volume. a 3dB difference in sensitivity will cause a doubling (or halving) of output volume when connected to the same amplifier. the ultimate level of sound under normal conditions you can get is going to be a function of the speakers rather than the amplifier. i'm keen to see others answer to this question... as athough i thnik i understand teh bits and peices well... I'm don't have a quaint explanation ready to go (probably becuase there are so many if's and but's to this discussion). Link to comment Share on other sites More sharing options...
Mika75 Posted October 2, 2009 Share Posted October 2, 2009 Polk RTi A9 http://www.polkaudio.com/homeaudio/rtia/specs.php The spec for this speaker is 90 db sensitivity (@ 1 watt input power we can assume) Amplifier Input power at 3 meters distance : 100 watts = 106 decibels SPL at the listening position. 250 watts = 110 db SPL 500 watts = 113 db SPL When u add distance, u lower the SPL Link to comment Share on other sites More sharing options...
davewantsmoore Posted October 2, 2009 Share Posted October 2, 2009 ... and a 3dB increase in SPL is a doubling of sound output (?!) Link to comment Share on other sites More sharing options...
JA Posted October 2, 2009 Share Posted October 2, 2009 ... and a 3dB increase in SPL is a doubling of sound output (?!) Hello DWM, Hmmm opinion varies on this issue as it is all down to human perception....doubling of perceived loudness by we humans is generally considered to occur with 6 to 10dB increase in SPL Best JA Link to comment Share on other sites More sharing options...
Poida Posted October 2, 2009 Author Share Posted October 2, 2009 Polk RTi A9 http://www.polkaudio.com/homeaudio/rtia/specs.php The spec for this speaker is 90 db sensitivity (@ 1 watt input power we can assume) Amplifier Input power at 3 meters distance : 100 watts = 106 decibels SPL at the listening position. 250 watts = 110 db SPL 500 watts = 113 db SPL When u add distance, u lower the SPL So what is the actual formula for figuring that out? Link to comment Share on other sites More sharing options...
Mika75 Posted October 2, 2009 Share Posted October 2, 2009 SPL Calculator http://myhometheater.homestead.com/splcalculator.html For you I set 90 db, distance of 10 ft, 2 speakers, near a wall. Link to comment Share on other sites More sharing options...
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