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Discussion Starter · #1 ·
is everyone else overstated?


The reason I ask is that I'm liking the HK 254 in every way except the stated power output of 65w per channel.


I may be overreacting as I admittedly don't know a helluva lot about HT setups or receivers.


The receiver would be used in a room that is 16x18 and would be running, for now, a 5.1 setup of Infinity speakers. At some point I will buy new speakers and move to a 7.1 setup.


So....will this receiver do the job for me or should I look at something else?
 

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They measure their AVRs with all channels driven which makes a substantial difference in rated power over brands which measure with only one channel driven. Another AVR, measured with one channel driven, may rate theirs as 100x7 watts, but if measured with all channels driven may drop to less than 1/2 of that.


Blame FTC for allowing one channel driven ratings. HK feels, for whatever reason, that rating is more honest/accurate whatever with all channels driven, hence the lower rating.
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by MichaelJHuman /forum/post/14154553


They measure their AVRs with all channels driven which makes a substantial difference in rated power over brands which measure with only one channel driven. Another AVR, measured with one channel driven, may rate theirs as 100x7 watts, but if measured with all channels driven may drop to less than 1/2 of that.


Blame FTC for allowing one channel driven ratings. HK feels, for whatever reason, that rating is more honest/accurate whatever with all channels driven, hence the lower rating.

Interesting. Makes it sound like the 254 would work for me then.
 

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Quote:
Originally Posted by shinerburke /forum/post/14154514


the HK 254 in every way except the stated power output of 65w per channel.


a 5.1 setup of Infinity speakers. At some point I will buy new speakers and move to a 7.1 setup.

Look at the specs. again.

The HK 254 is 65W x2 or 50W x7.
Figure about 56W x5.
 

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Discussion Starter · #5 ·

Quote:
Originally Posted by QZ1 /forum/post/14154623


Look at the specs. again.

The HK 254 is 65W x2 or 50W x7.
Figure about 56W x5.

Think that would be good enough for my room size?
 

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It depends on which Infinitys. But, I am not an expert by any means on speakers, so when you do tell us the speakers, someone else could maybe chime in.


But, in general, form my reading at AVS and talking to a speaker/HK AVR dealer, at that room size, the way HK rates their AVRs, I think it would be fine at reasonably loud levels.


Now some want to get full dynamics at very loud levels, then it becomes trickier to tell, especially without knowing the exact speakers. HTH
 

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I say go with the 354(75 wpc) and you shouldn't have any doubts! That's what I'm doing.


Plus you get The Bridge II($129 value), 1 more component input, 1 more optical input and it's only $200 more.
 

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I had a 247 for 3 weeks in a room that is a lot bigger. I have Klipsch Reference series speakers and the 247 drove them to dangerously loud levels without any distortion. The 254 will be plenty enough. Remember you have to double the rated power of the amp to get your speakers to play just 3dB louder. What is more important is the instant current availability. It is 35 Amps for both the 254 and the 354.
 

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That's plenty of power for your room. The HK amp you're looking at is rated 50W RMS into 7 channels. That's an honest, true, all-channels-driven rating. Take it to the bank.


Here are some numbers for comparison. Sound & Vision Magazine tested the Pioneer flagship VSX-94TXH that is rated 140Wx7 by Pioneer, and came up with the following results (copied from the S&V review):


7 channels driven (8 ohms): 61 W* (17.9 dBW)


As you can see, it only delivered 61 watts x 7 channels, and then the amplifier went into protection mode. So, you can see, you're not too far behind with that HK amp. =)


Greg
 

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Quote:
Originally Posted by bommai /forum/post/14154775


I had a 247 for 3 weeks in a room that is a lot bigger. I have Klipsch Reference series speakers and the 247 drove them to dangerously loud levels without any distortion. The 254 will be plenty enough. Remember you have to double the rated power of the amp to get your speakers to play just 3dB louder. What is more important is the instant current availability. It is 35 Amps for both the 254 and the 354.

You're not gonna get 35A into any functioning commercial speaker. Maybe you'll get 5 or 6A if they dip to 4 ohms. That's it.
 

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Quote:
Originally Posted by hammong /forum/post/14154781


That's plenty of power for your room. The HK amp you're looking at is rated 50W RMS into 7 channels. That's an honest, true, all-channels-driven rating. Take it to the bank.


Here are some numbers for comparison. Sound & Vision Magazine tested the Pioneer flagship VSX-94TXH that is rated 140Wx7 by Pioneer, and came up with the following results (copied from the S&V review):


7 channels driven (8 ohms): 61 W* (17.9 dBW)


As you can see, it only delivered 61 watts x 7 channels, and then the amplifier went into protection mode. So, you can see, you're not too far behind with that HK amp. =)


Greg

With that equation, HK 50W x 7 = Pioneer 115W x 7.
 

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To respond to original question: Is this enough for my room, driving Infinity speakers. As QZ1 said, that depends on the speakers.


To know this, most speakers have a "sensitivity" spec. If they follow the standard, it is the output audio power, in dB, measured 1m away from the speaker in an anechoic chamber with 1W power driving 1 speaker.


Be careful on this spec though, as with amplifier power, these numbers can be tweaked to be misleading, some manufacturers say "in room stereo" which means in a "typical" listening room with 2 channels driven. So, with 2 speakers you get +3dB, and the room adds some too.


Now, to determine how much power you need, consider that amplifier power in watts doubles for every 3dB greater output from the speaker.


So, if you want to achieve THX reference level of 105dB peak output from speakers with, lets say 90dB sensitivity, that is 15dB more than you get driving 1W. For now we won't worry about distance to listening position, because the number of speakers around you should help make up for that. So, to get 15dB more that is 5 times 3dB, so you need the power to double 5 times, or 2^5 = 32W


A quick look at Infinity's website shows that 90dB is a reasonable assumption for most of their speakers, some are 93dB so you'ld need even less power to achieve 105dB. Also, note most people rarely listen at this level, it is very loud.
 
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