Dear Roger:
While we're on the subject of power, I get the impression that you don't buy into all the hype that certain reviewers in magazines like The Absolute Sound parrot about how it is necessary to have as much amplifier power as possible, and that speaker manufacturers underestimate the power requirements of their speakers. I seem to remember a statement of yours about "wasted watts." I am beginning to think that you are absolutely correct in this; contrasting the rather bass-heavy, congested sound that I would get from my older Counterpoint SA 20 (200 wpc) and even with the RM 9 connected at the 8 ohm taps and HI gain with the greater transparency, naturalness and bass impact (when called for) that I now get convinces me that sheer brute power output is way overrated. It may well be that part of the difference is the increase in the Class A range that you mentioned. All I know is that at the current settings, I get simply MUSIC from my system, rather than "impressive hifi."
Ralph
Ralph, you are correct, I do not buy the notion that one must have unlimited power. One must remember that the majority of writers of TAS are not very technical or interested in circuit design. They just listen to stuff and write. As to speaker manufacturer's they more likely overestimate the Sound pressure levels (SPL) that most of us listen at. Speaker sensitivities have gotten higher over the past 10 years and many listeners, myself included, have found that the better the resolution of our system is, the lower volume is required to hear everything. If you compute the level of a 90 dB/watt speaker and a 100 watt amplifier you get 110 dB SPL. Many of us listen at 70-80 dB SPL which means we only need one tenth of a watt for that speaker.
As many of you know, I started Audio Art in Richmond Virginia in 1976. We had big listening rooms, Magnepan MG-2s and SAE electronics in one listening room. I would often put on the vinyl brought or selected by the customer, show him to the volume control, tell him to turn it up as much as he liked because the 100-250 watt SAE amp could not blow up the MG-2s. Then I closed the door and left the room. The house we were using for our store was built in 1865 and had one foot thick brick walls. I often heard some pretty loud sound coming through that I would estimate to be 110 dB SPL.
We also had a room devoted entirely to Electrostatic speakers and high quality tube amps. In that room sensible customers could hear every detail at 80 dB. In that room I could stay and visit with customers.
I have been swimming against the tide of high power for some time now. The little RM-10 surprises people in it's ability to drive a wide range of speakers. It has plenty of headroom
If you listen below one watt it matters not if you have 19 watts of headroom or 99 watts. You need some headroom but consider the following: I have looked at a lot of CDs on the oscilloscope. A large number of them actually show clipping of the source material. In Willie Nelson's Stardust, there are several places where the drum rim-shot are clipped. I would say the headroom on that CD is about minus 6 dB. The guy who re-mastered that should be fired. I have the same recording on vinyl and it doesn't clip. Perhaps this is one of the reasons that vinyl is coming back. Digital is not a bad medium but it is being abused by producers, artists and recording engineers. With over 100 dB of dynamic range and a master tape with at best 70 dB range, why do you have to remaster the CD into clipping? I have often said that when you notice a CD plays significantly louder than others it is severely compressed or clipped.
Even if we have great source material The concept of unlimited headroom is a false one. Weather by choice or necessity, TAS has taken on reviewing the most expensive equipment out there. In the September 2011 edition Robert Harley, being about the only technical guy they have, had the task of reviewing a 1000 watt mono-bloc amplifier that costs $140,000 a pair. He felt that SET (single ended triode) amps have a more palpable and direct communication in the midrange. Later he mentioned that although the bass was deeply extended and powerful it was not the last word in fullness and heft. Well, SETs are generally low powered so there goes the unlimited headroom notion and that a very expensive amplifier is the absolute best.
I've been promoting "Light Loading" because it improves the low power range of a high powered amp. I see that several members here are trying it out with good results. Indeed when you put an 8 ohm speaker on the 4 ohm tap it sounds better because now you have a 20 watt amplifier with a larger class A region, more damping and flatter response. I have measured and heard the difference. Since the RM-10 is capable of over 35 watts per channel, you still have the option of that power should you need it for a party by simply using the 8 ohm tap.
