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Discussion Starter · #1 ·
I am currently using an Aerial Acoustics LR5 for my center channel speaker. I am using my Parasound HCA-1206 to power it along with the rest of my speakers in my 5.1 system.


The LR5 is rated for 4 ohms, and, has an efficiency of 86 dB. My Parasound is feeding it 180 watts at 4 ohms.


I've read as many posts as I can regarding this topic and most all agree that the LR5 is a power hungry speaker and needs a significant amount of power to sound its best.


I play at moderate listening levels since I don"t have a "dedicated" theater room. I don't think I have ever heard my speaker distort or "clip".


I know the theoretical arguments supporting the need for a more powerful amp. But, PRACTICALLY, would I really tell an audible difference in my situation? I am trying to decide if the cost to upgrade the amp would be worth it. If money was no option I would do it. But, that is not the case here.


Thanks
 

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I believe in ohm's law. Ohm's law says that your speaker will not demand more power than the signal dictates.


If for example, your average voltage is a half volt, and your average impedance is 8 ohms, your average power is .03 watts.


Of course, it's the peaks you would be worried about. For a 20 dB peak, you have 10 times average voltage.


So rather than a half Volt, you have 5 Volts, or 3 Watts.


This is simplified because impedance adjusts dependent on frequency. Four ohms, would double power to 6 watts.


Now I am not an EE, so I may be missing something. But moderate volumes, and no obvious distortion/harshness indicates to me you are fine.
 

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You might want to consider auditioning more efficient speakers, e.g. with more than a 93db sensitivity.


That kind of speaker is power hungry because of its relatively low sensitivity of 86db. That's fine in a small room, but larger rooms will need powerful amps to get the sound level up where you may want it. A 3db increase of sound level requires doubling the amplifier's power.
 

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Discussion Starter · #4 ·
Thanks Guys...I do believe the Parasound is "adequate" for the Aerial LR5. I really do not want to downgrade from the LR5 to a speaker with higher efficiency; I have been spoiled
I have considered maybe at the most going down to an LR3.


I am wondering, though, since I am feeding it a relatively low amount of power, am I giving up any noticeable sound quality (at moderate listening level) by not using an amp with double the power?


If I can find one available maybe I will demo a larger amp in my system to see if I can tell a difference.
 

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Quote:
Originally Posted by jdlynch /forum/post/18135375


Thanks Guys...I do believe the Parasound is "adequate" for the Aerial LR5. I really do not want to downgrade from the LR5 to a speaker with higher efficiency; I have been spoiled
I have considered maybe at the most going down to an LR3.


I am wondering, though, since I am feeding it a relatively low amount of power, am I giving up any noticeable sound quality (at moderate listening level) by not using an amp with double the power?


If I can find one available maybe I will demo a larger amp in my system to see if I can tell a difference.

That was what my explanation was trying to explain. I don't understand the claims that having more power on tap will help you if you never use it. In my mind, it's basic electronics. I am not an EE, so maybe I am missing something.


I have read claims which contradict my theory. Some people will claim a new amp sounds better than their old amp/receiver even at lower volumes. But there could be other variables than power.
 

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Discussion Starter · #6 ·
Thanks Michael. Your response is exactly what I was looking for. Too many recommendations and purchases are made for misguided reasons. I don"t mind spending money, but, I do want something tangible in return when I do.
 

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Discussion Starter · #7 ·
I just checked Aerials specs to compare the LR3 to the LR5. They are both rated for 86 dB sensitivity, however, the LR5 is spec'd @4 ohm, the LR3 @ 6 ohm.


Does this mean the larger LR5 is easier to drive with my amp than the LR3 would be?
 

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Quote:
Originally Posted by MichaelJHuman /forum/post/18135973


6 ohms is easier to drive than 4 ohms

That's true of most AVRs where the amps are current limited. Many separate amps, however, can put more power into a 4 Ohm load than they can into a 6 Ohm load (because they're voltage limited).
 

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Discussion Starter · #10 ·
Somehow my logic is off....looking at my amp specs, it is feeding 130 watts into 8 ohm, and, 250 watts into 4 ohm. Given those specs I assumed at 6 ohm that the watts being fed to the speakers would be less than 250. I thought that implied the higher ohm rating would be easier to drive.
 

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The mentioned Parasound amplifier puts out about 200W/CH into 6 Ohms, it will work fine driving your LR5 loudspeakers. We are very familiar with the Parasound amplifiers, and they do very well into lower impedances significantly better then any amplifier section found in any AVR..


Just my $0.01...
 

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I have a 1205 parasound and dayton d3 speakers. Pretty similar speakers and a the exact same power output amp.


I am picking up microphone this week to determine what "moderate" listening levels for me actually is, is it 105db or lower? I do know that I hit 15 volts according to my DMM on my fronts and my center and when I run the power calcs I hit about 46watts at my "moderate" listening levels so I have about 100watts left over.
 

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Quote:
Originally Posted by Dzhokhar /forum/post/18136022


That's true of most AVRs where the amps are current limited. Many separate amps, however, can put more power into a 4 Ohm load than they can into a 6 Ohm load (because they're voltage limited).

By easy I mean less heat and less load on the power supply (all other things being equal.)


Of course, you are right that I simplified the situation. If you are voltage limited, lower impedance speakers may be better for power. I have often wondered if that's how HK does things. Use a lower voltage rail, which looks worse (that their competitors) on the bench, but does very nicely when faced with real world loads.
 
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