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Hello Peng,
Thank you for your response.
The concern with Class D Power Amp is that if it’s above 200 watts then chances are that it might overpower my other speakers - JBL 630/625C & S.F. Aster which are of 150 & 125 Watts. Even Sonetto II G2 is of 200 watts.
So in this case, the only option I have is Rotel Power Amps mentioned above as they offer pure 120 watts but yes, my Sonetto II G2 being of 200 watts, it will fall short of 80 watts which means it will not be driven to it’s fullest.
I understand this kind of concern is normal because there are many internet hearsay that are often rooted in misconceptions.
To understand it more, consider the following facts:
1) It does not matter how powerful the power amp is, your speakers will only draw what they need based on:
a) their sensitivity that is often given in XdB/2.83V/m, such as your JBL 630"s: 85dB @ 1M, 2.83V
b) your distance, because when distance is double, you lose 6 dB, likewise, you sit closer to say 0.5 of your original distance you gain 6 dB (that's equivalent to 4 times the power).
c) your listening habit, typically you will perceive about twice as loud if you have 6 to 10 times of the "power" applied to your speaker.
d) Before your speakers get damaged due to being "over powered", they will tell you loud and clear, as you will hear distortions long before that point is reached.
e) Despite fact d) above, it is true that speakers do get over powered frequently probably without audible distortions because there could be high peaks in some music that have very high dynamic peaks, but such short duration peaks won't cause damage, unless it is really high, that won't likely happen for real world use.
f) Even if you do get those rare extremely high, even damaging peaks, keep in mind that the less powerful Rotel amp won't make a difference because they can output very high power for short duration, and even if they cannot, it would mean the amp output voltage will clip, and that could also damage your speaker, especially the tweeters, such in different way.
Notes on points above:
on f), you must have read about the often debated topic on the internet, about whether speakers are more often damaged by under powered amps than over powered amps right? Both could be true, it just depends on a few other factors, topic for another day.
on b) is a rough estimate because you likely have room gain in the low to mid bass range, so you won't feel losing 6 dB, more likely 3 to 4 dB loss when you double the distance.
on c) again, just a rough estimate because our perceptions are not exactly the same, to some 6 dB would feel like twice as loud whereas some may need 10 dB (that's 10 times the power) to feel the same.
In case you are not familiar the dB, that is log scale, typically used in audio, take a look of the following table:
dB chart voltage power table conversion sound pressure sound intensity decibel voltage level levels ratio dbu dBA dBm absolute relative acoustic measurement volts watts and pascals database - sengpielaudio Sengpiel Berlin
So, please suggest me a good Power Amp which offers atleast 140 to 150 Watts & is 5 channels driven b’coz I would like to drive all except the Surrounds via an external Power Amp & leave the Surrounds JBL 630 to the new A/V receiver to drive completely.
It has been suggested already but you don't seem to understand, or believe?
In the links to some of the class D amps you can sort out those that are rated around 150 W, but you will be ill advised for reasons before, that is, use an online calculator to figure your actual "power need", before making a decision. Amps last for a long time so it is worth spending time on gathering up all the facts.
If you have trouble using one of those calculators, I don't mind doing it for you if you provide the following information:
- your seating distance.
- your desired SPL you listen to, keep in mind, 85 dB average 105 dB peak is likely what you would be listening to when watching a Star War movies, Jurassic park etc.
- Do you often listen to highly compressed music, such as many on youtube, rock concerts etc.
- Do you listen to classical music including large symphony orchestra's.
Just a question here, can my Dolby Atmos speaker - Sonus Faber Aster on the Ceiling be driven by Power Amp or just Front & Surrounds speakers be driven by a Power Amp?
Same answer as above, need the facts based on you needs, so have to know your distance from the individual speakers.
Now, you can ignore all those requirements such as using an online calculator and go with the highest power amplifiers based on the speaker manufacturer's recommendations. For example:
For the Sonetto II G2 4 Ohms speaker, the specs say: 20-200 W, so a good recommendation would be to use amps rated for 400 W into 4 ohms, that would assure you can listen at the speaker's power handling limit during peaks, without causing damage. Peak power = 2X average power (that's just one of several facts to consider).
This is sort of a short cut, bypass the need of doing the calculations to determine your actual need. If you actually do the calculations, then you might find the 150 W Rotel is already powerful enough to get the best out of your Sonus Faber speakers, but if you ever change you habit such suddenly love to watch THX movies that have 105 dB peaks, and/or large orchestral music that has very high dynamic peaks, and/or moving to a larget room where you would sit further, examps: 15 feet from the speakers, then the 150 W Rotel won't be a good match. They would still be fine, but you won't get the best out of those very nice speakers.
The reason I want to drive the Aster with Power Amp is b’coz I am unable to feel the Dolby Atmos effect & that’s possibly b’coz my Yamaha RX-V685 A/V receiver is of an entry level & unable to meet power demand from all 7 speakers.
So, driving the overhead Aster Atmos speaker via a Power amp will definitely get me a pure Atmos feeling experience, what’s your suggestion on this?
Again, figure out your actual need first, general statements don't really help in getting the answer you need.
The back of my Yamaha A/V receiver has Sub 1 & Sub 2 under Pre-out & I think previously, I used to connect the Nedis audio cable into the white connector behind this JBL 660P but now since it doesn’t function, I have to use the Red one which isn’t giving out that deep impactful bass even at lower volumes like I used to get before when the Nedis audio cable was plugged into the white connector I guess of the JBL 660P.
I dealt with that question already in my last post, may be you missed it?
Also this Yamaha A/V receiver that I had handed over to their authorised service center last Saturday to have them check the Center Channel connector issue due to those sudden frightening crackling sound from JBL 625C, just checked with the service center team yesterday & they couldn’t find any such fault.
If the fault is of intermittent nature, it will be hard to find.
How can both JBL 625C Center channel & JBL 660P develop such faults at the same time, really can’t understand it. Could this newly added power hungry Sonetto II G2 4 Ohms speaker be the reason for it?
As I said before it is a possibility, though I would say unlikely. It is not hard to find out, you can simply disconnect those Sonetto II G2 and do some experiments without the influence of them.
Anyway’z, I have informed the JBL representative about these issues & they will have it checked. I have requested them to kindly bring in their own A/V receiver, even a simpler one will do. This is just to check whether the Center channel again creates the sudden crackling sound when connected into their A/V receiver? Let’s wait & see.
All good ideas, hopefully they will listen to you.
In discussion, they also suggested me to consider:
Arcam PA720 which is Class G amplification but what I fail to understand is that it mentions 140 watts per channel under the description but down their on next page, it mentions - 7 x 100W Class G amplification. It’s quite strange.
Why it is strange, to me that's typical, you get less when driving 7 channels simultaneously, vs 1 or 2 channels.
Overall, I am totally clueless with my purchase decision b’coz many audio dealer also asked why I bought a 4 Ohms speakers in a 6 Ohms environment b’coz rest all are 6 Ohms in my living room & I now feel I shouldn’t have purchased this Sonetto II G2. I feel adding an external Power Amp & whether upgrading or to stay with the present A/V receiver - RX-V685 should give me best output but again, the Power Amp which will now drive these power hungry Sonetto II G2 speakers, it’s sound will be such large (over power all other speakers in this living room) that all other speakers will get pressed under it.
Many such dealers are not that knowledgeable, they have some basic knowledge but if you have done your own research and evidently you have, I would be willing to bet you are actually more knowledgeable than some of them. So, you are doing the right thing, instead of taking their words for it, you come here and ask questions.
It has all become so much of a confusion now & this Class A/B, Class D or now this new from Arcam - Class G - I feel as if I am back to school days where teacher teaches - A for Apple, B for Ball, C for Cat & so on…as if I am learning A,B,C,D,…
What’s all of these different Class, really clueless about it.
Again, you came to the right forum, one of the best on the internet for those who are scientific minded, objective and want to learn.
So, try the following article and if you have specific questions about anything in it, do come back and ask for clarification:
What are the Different Types of Audio Amplifier Classes?
Overall, I am just so worried that these power hungry Sonetto II G2 doesn’t damage my other speakers or itself or this present or new A/V receiver that I look forward to buy.
No one can help you much on this, unless and until you have done your home work, at the minimum use one of the easy to use (but not the best) calculators:
Peak SPL Calculator
Crown Audio - Professional Power Amplifiers | English
for the better, but more difficult to use ones, such as Benchmark's, iirc I've posted links to it/them before already.
My dream of setting up a very good Home Theatre experience has turned into nightmare & miserable.
You can achieve you goal, but you have to be willing to read and understand more, and stop worrying much about what the dealers told you, some of them more quite knowledgeable, but many are not.
Maybe due to such extreme complications & lack of exact & true knowledge about the Home Theatre systems, so many household across globe still consider enjoying sound from their regular TV instead of opting for a home theatre setup l, while it’s cost of setting up being another important factor to be considered & it’s maintenance thereafter…(-:
It’s all too very much of technical & not a normal buyer’s cup of tea for sure. Things are way too complicated in this home theatre world & no one has time to sit & learn it in this day to day hectic & busy stressful life. (-:
I can understand the feeling, and I think that is why so many people would just pick an AVR, and use such a one box solution. In you case though, while you can do that, if you want to get the best of your near high end speakers, it is still a good idea to use a 3 channel power amp to assist whatever AVR you picked, unless you are willing to pay for the flagship models such as the expensive, Denon AVR-A10H, Onkyo RZ70, or the Cinema 30. Imo that would be for those who just want to get by, and in my opinion the value kings such as the AVR-X3800H/X4800H, or Marantz Cinema 50 plus a 500 W 4 ohms class D power amp will be better choices but now I am repeating what I and others suggested long time ago lol..
