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Post by goozoo on Jul 6, 2017 14:24:52 GMT -5
This is a question that many people struggle with and the answer really is "it depends". The mistake that most make is to equate more power with greater volume. This is not true and you will find out that once you upgrade the amp, the gain levels on your pre/pro will pretty much stay the same. Having more headroom does however translate into a greater sense of immersion in cinema and a perceived greater extension of audio range when listening to music (especially in the lower frequencies). What you have to concern yourself the most with is what is referred to as the transient response; i.e. that brief instant where the sound becomes elevated and the amplifier is pushed to reproduce it. This is what can blow drivers if the sound is distorted (poor amplification) or well beyond the rated limits of your speakers. Most consumer speakers are not rated beyond 300-400W, with many in the 120-250W range. At 500WPC on a speaker rated at say 200W, a transient sound may push the driver so far past its' rated limit (XMAX)that it blows; even though it was just for an instant. Another piece of the equation that one has to consider is the electrical load placed on the circuit into that room. Amps = Watts / Volts. Most rooms have one to two 15-20 amp circuts running all the outlets. 1000W/120V=8.3A for this amp alone. Finally, space becomes a major factor with regard to listening levels; with smaller to medium sized rooms producing peak SPLs in excess of 110dB based on the physics.
The question that you are really asking is whether or not having more power in the rear channels will make a difference for watching movies and I would say yes. Taken further, I think that with today's modern lossless audio tracks, a minimum power requirement is 200-300WPC of CLEAN amplification. Beyond 300WPC for cinema, and you are talking larger commercial venues or spaces with the corresponding speakers and electrical wiring to handle the load. While many (audiophiles) reading this response will argue that they can run the XPR-1 monoblocks, rated at 1000W, for their musical listening into each speaker, you have to keep in mind they are talking only 2 speakers and not 5, 7, or more at that level. Even with two channels, they cannot circumvent the physics and will blow their uber expensive speakers if played two loudly.
The final comment I would make is (based on the quality of your speakers), the importance of timbre matching your amps and speakers. As you are experiencing, there is a certain synergy that occurs when the recipe is just right, and "off" when mismatched. If you are going to upgrade, then do it for all your channels and not just the rears.
Best of luck...
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Post by garbulky on Jul 6, 2017 14:47:41 GMT -5
If you plan to step up to the (assume price) $5000 RMC-1 which is fully balanced on all channels this may be a nice match. But honestly it's probably overdoing it. If it was me, unless I had money to burn I would not bother with all that.
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bootman
Emo VIPs 
Typing useless posts on internet forums....
Posts: 9,358
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Post by bootman on Jul 6, 2017 15:38:42 GMT -5
If it was my money I doubt there will be that much return on sonic investment especially for rear channel use.
You should get a sound meter and with real music, test levels while muting channels to see how much real output you are currently getting in each speaker.
Subjectively you say so why do you think you need more power? (especially in the rear?)
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Post by metaldaze on Jul 6, 2017 16:38:55 GMT -5
Thank you for your input. I should make a note that my current system is primarily for music listening. Both turntable and my tower for digital. Normally I use the turntable in 2 channel configuration. However for digital music- my tower has a nice sound card and can output dolby 5.1 in multiple formats which i do use from time to time.
Its currently set to quadraphonic output so my receiver sees 4 channel PCM for music. The reason I'm asking about more power for the 'rears' is because they aren't really rear channels like most home theaters marketed today. They are basically directly to the left and right of my listening spot, with the fronts being 9' apart and 9' away from me to form a triangle. For music they seems to receive as much information as the fronts do.
All the speakers are the same make, same nominal impedance, same sensitivity. Its just that with the 'rear' channels being stacked in parallel it presents a greater load to the amp. There are 2 20 amp breakers in my apartment and the XPA 4 is plugged directly into one, the receiver into the other. Everything else through the power conditioner. I realize double the power = +3 Db and current out of the wall isn't directly related to watts.
I appreciate the overpowering and under powering of speakers, but the power from the emotiva is clean so im not worried about that. Also with the speakers being factory upgraded they have circuitry that naturally rolls off frequencies as well as a self resetting circuit if indeed they are overpowered.
So unless i really try to push the amp to where my neighbors are getting pissed, there isn't much excursion on the rear channel woofers. Again i know excursion is not equal to SPL. However my dad has two pair of the same speakers in original condition hooked up to an Onkyo TX 4500 monster from the '70's. When he turns up something like Zeppelin the speakers are really moving. Yes they're well broken in, but does this infer that the XPA 4 is just controlling mine better? Or are they hungry for more power?
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Post by leonski on Jul 10, 2017 12:08:57 GMT -5
This is a question that many people struggle with and the answer really is "it depends". The mistake that most make is to equate more power with greater volume. This is not true and you will find out that once you upgrade the amp, the gain levels on your pre/pro will pretty much stay the same. Having more headroom does however translate into a greater sense of immersion in cinema and a perceived greater extension of audio range when listening to music (especially in the lower frequencies). What you have to concern yourself the most with is what is referred to as the transient response; i.e. that brief instant where the sound becomes elevated and the amplifier is pushed to reproduce it. This is what can blow drivers if the sound is distorted (poor amplification) or well beyond the rated limits of your speakers. Most consumer speakers are not rated beyond 300-400W, with many in the 120-250W range. At 500WPC on a speaker rated at say 200W, a transient sound may push the driver so far past its' rated limit (XMAX)that it blows; even though it was just for an instant. Another piece of the equation that one has to consider is the electrical load placed on the circuit into that room. Amps = Watts / Volts. Most rooms have one to two 15-20 amp circuts running all the outlets. 1000W/120V=8.3A for this amp alone. Finally, space becomes a major factor with regard to listening levels; with smaller to medium sized rooms producing peak SPLs in excess of 110dB based on the physics. The question that you are really asking is whether or not having more power in the rear channels will make a difference for watching movies and I would say yes. Taken further, I think that with today's modern lossless audio tracks, a minimum power requirement is 200-300WPC of CLEAN amplification. Beyond 300WPC for cinema, and you are talking larger commercial venues or spaces with the corresponding speakers and electrical wiring to handle the load. While many (audiophiles) reading this response will argue that they can run the XPR-1 monoblocks, rated at 1000W, for their musical listening into each speaker, you have to keep in mind they are talking only 2 speakers and not 5, 7, or more at that level. Even with two channels, they cannot circumvent the physics and will blow their uber expensive speakers if played two loudly. The final comment I would make is (based on the quality of your speakers), the importance of timbre matching your amps and speakers. As you are experiencing, there is a certain synergy that occurs when the recipe is just right, and "off" when mismatched. If you are going to upgrade, then do it for all your channels and not just the rears. Best of luck... Good idea, but speakers do not have watts. The idea of speaker maximum power is based on the idea that it can be objectively measured. This short article from JBL, who Really Know their speaker stuff should help. www.jblpro.com/pub/technote/spkpwfaq.pdfOr at least if a maximum power is listed, the measurement method is also listed. Peak? RMS? Time Limited? And when listening, do you hear AMP distortion or SPEAKER distortion first? Or at ALL? The manufacturer who gives a rating should also say How that number was arrived at. Can a transient happen so quickly it damages the speaker and you don't Hear it happen? I'd guess yes to that. Speakers also change electrically as they WARM. Don't forget that a loudspeaker in-home is typically around 1% efficient. The rest is HEAT. And when a voice coil gets hot, it changes. And not for the better, electrically. If you are curious about amplifier power draw, get a Kill-A-Watt meter. They are very inexpensive, running maybe 25$ these days. You'll see the huge draw of an amp from a cold startup. Some amps even have a way to limit power inrush. But that 1000 watt amp? I don't know how much power it'll really demand. You seldom use full, RMS power, so it will never be a continuous load. The idea is that the PS capacitors don't recharge until the PS voltage exceeds the capacitor storage voltage. And than the recharge is only for that part of the power cycle in which the voltage is above that floating limit. Don't get me wrong, when pressed, that amp WILL put a dent in your electric bill. Conventional A/B amps are only 50% to maybe 60% efficient, anyway, the rest being heat, once again. Huge link, but will go direct to the meter, for only 20$. www.amazon.com/dp/B00009MDBU/ref=asc_df_B00009MDBU5069228/?tag=hyprod-20&creative=394997&creativeASIN=B00009MDBU&linkCode=df0&hvadid=167125429392&hvpos=1o1&hvnetw=g&hvrand=4274391176043718796&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031303&hvtargid=pla-306572288073 |
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Post by metaldaze on Jul 12, 2017 9:54:37 GMT -5
After doing some more research & head scratching on my own I'm coming to believe that, between the passive cross overs in the speakers themselves in addition to having the circuitry added to enhance their power handling and bass response- the amplifier has a very high damping factor. High enough in fact that when all the variables are added together this appears to be the missing piece i was looking for. SPL's have been more than adequate for my current residence so I must resign to the idea that the woofers are being controlled to a much greater extent. My dad's Onkyo shows a damping factor of 50. The XPA gen 3 is 10x more at 500. 250 for 4 Ohm loads.
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Post by leonski on Jul 12, 2017 12:11:08 GMT -5
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Post by metaldaze on Jul 12, 2017 12:26:10 GMT -5
No It comes down to me trying to determine if they need more juice. The movement is just a variable in my line of questioning. The damping factor I thought might be part of the explanation. |
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