Amplifiers...., Strife-Testing! Options

[soundminded]

Well now, reading all the historical info, I'd have to say that it was a more a sales job/magic show than the real thing that I thought it was!

I had thought that the way the quartet thing worked was that the musicians were behind a screen playing live and that at some convenient pause or at an agreed point, they stopped and the tape was started. The audience wasn't told (I thought) whether they were hearing the tape or the musicians at any given moment. In other words, I thought there was actually a live vs recorded performance taking place in real time. I didn't know until reading that account, that the music was "lip synched" to the tape and that there was never a direct live comparison on site.

So IF I'm understanding this correctly I must admit that I am less impressed with these AR demos than I used to be! True, nobody else did it. BUT that could simply be because because AR thought of it first.

This added later: One thing that REALLY surprised me was the fact that these tests were apparently REALLY hard on amplifiers. There was a comment that some amps tested lasted only 10 minutes. I would have thought it would have been hard on the speakers but once again it appears that amp capabilities are more strained than is often thought...

The live versus recorded demonstrations were no magic show. They were not tricks. However, it is true that deception was used to confuse the audience. This however in no way diminishes from what was demonstrated. The audience heard both the live musical instruments and the recordings. They just didn't hear them at the times they thought they did. Had there been really gross differences, they should have been able to detect the decption easily. That they couldn't proves either that the reproductions were close, the audience weren't nearly as critical listeners as they thought they were (I've got more than one direct experience proving the possibility of that), or both. The problem is that the inference one would like to draw, that the results of such a close reproduction under what must be admitted were highly controlled and contrived circumstances cannot be extrapolated to different and more common experiences of listening to commercially made recordings at home. In these cases, those same speakers can produce results which are less accurate than others because many other variables play a significant role in the results. Those variables are not controlled, may be uncontrollable, and some of them not even understood.

The ability to listen is distinct from the ability to hear just as the ability to look is distinct from the ability to see. My eyesight is no more accute than it was when I was a child but lots of experimentation with and reading about painting and photography has taught me how to look, how to analyse and make critical judgements of what I see, and how to selectively compose images and judge the compositions of others. It's the same with hearing. At some point I will write a piece on how I listen (or have I done that already?)

The BAS paper was very interesting. It revealed many things about the speaker I've believed true. The inability to reproduce the bass drum IMO stems from the falloff of deep bass of the speaker, down 3db at 42 hz and falling at 12 db per octave. Had an equalizer been used and enough amplifier power been available, that could have been corrected. The slight boxiness was due to a midrange peak and the slight rolled off high end for some listeners were both correctable with an equalizer. The intensity of live drums in a small room was not a good choice IMO to demonstrate the merits of AR10pi as the SPls were deafening. "Drums were chosen to test power handling and reproduction of very-high peak levels, whichturned out to be around 130 dB in the rear field." This is ten times the threshold of pain, a dangerous sound level and a risk of permanent hearing loss to those exposed to it. It also masks any defects in the timbral quality of the reproduction. Most circumstances where an audience hears this type of drum is from a much safer distance than this 22' x 26' room allowed.

The part about the Scotch tape reminded me of something that happened to me in the 70s I'd completely forgotten about. At a trade show, I met the chief engineer of Maxell. He tried to demonstrate to me the superiority of his best tape formulation over TDK's best. He had a Nakamichi Dragon tape deck and a lot of test equipment. He ran the tests and showed me the curves. I told him I was unconvinced and wouldn't be unless he optimized the tape deck's bias and equalization for the TDK formulation and ran the test again. To my surprise, he offered me a job on the spot. Unfortunately I couldn't accept because I had no transportation to Moonachi New Jersey every day at that time. Years later, I worked for a company that made coated plastic products in Sunnyvale Ca. Their main product was microfilm, they were the #1 producer with about 70% of the Market. They were trying to break into the magnetic media market which was hot at the time. I asked their engineers in this field which was the product to beat or at least match. They said....Maxell. Somehow I already knew.

[genek]

I told him I was unconvinced and wouldn't be unless he optimized the tape deck's bias and equalization for the TDK formulation and ran the test again.

Talk about nostalgia. It's been years since I owned a tape deck. I had forgotten how the biggest part of every deck purchase I ever made was trying to pry out of the manufacturer what brand and type of tape they had used to setup the bias, EQ and Dolby at the factory, and how happy I had been when I finally got my hands on a decent three-head deck with user adjustable trims for all.

[KlausDK]

Dear Fellow CSP's.

Realising (long time ago) that I will never be in the pay league af a McIntosh amplifier, I have investigated other - budget wise - reasonable high power alternatives for driving AR speakers. A long the lines of TT's suggestion, I have lately managed to come across a couple of Hafler DH-500 Hitachi MOS-FET semi-pro power amps, that seem to drive my LST's very easily and never really run hot. These amps delivers about 2x400 Watt into a 4 Ohm load and they are even more reasonably priced in their home-country US compared to Europe, judged from the prices I see at ebay.

BRgds Klaus

[ar_pro]

Yes, that's an excellent combination. The DH-500 is a very reliable amplifier, as well.

[Rlowe]

While trawling the web I ran across another article on the AR live vs recorded demonstrations, where Roy Allison recalls his involvement and many other things. Summer 1992.

Audio Critic – Available from;
http://www.theaudiocritic.com/cwo/Back_Issues/
Volume 18, page 56 (page 49 in PDF)

Topic;
Interviewing the Best Interviewees in Audio -Part 1.
David Ranada asks Roy Allison;
Were you involved with those live vs. recorded demonstrations at AR?

[Mexicomike]

Interesting article - Since it agrees with my personal opinion re AR, I was glad to see Allison's comments that after the LST, Teledyne fired some high-up AR folks and changed AR's orientation to a totally market-driven operation, wanting to increase market share. In my PERSONAL opinion, the LST was the last of what I would consider the classic AR speakers, founded on the original company's (Villchur) principles and design goals. I realize this is JUST MY OPINION and is not shared by others but I would not consider any post-LST speakers as "classic AR."

[oldguide]

Tom,

Perhaps this post is out of order in the sense that it relates to amps not ARs. Plus I hate to put you in a corner, but do you have any recommendations? I began this odyssey by rebuilding my old AR3 with much help from Roy C, JohnnieO, you and others. I recently finished rebuilding/redoing an old Dynaco PAS 3X tube preamp which sounds great with the ARs even running an old Dynaco 120 with caps that look ready to go at any minute.

I tried a Crown D150A I picked up at that auction place and it lasted about a week before it quit. On opening it up it looked as though someone had tossed a firecracker in there and the caps that had not blown were about ready to. While it worked the sound was quite good. Having learned my lesson with the Crown I ordered a new QSC RMX 850. Problem is wife acceptance factor. In order to get any decent sound at all from the speakers you have to listen at something above a whisper, but unfortunately my wife only wants to listen an extremely low levels (what is it that women want their music at a whisper)? Does it make sense to go with less power (i.e. Crown D-75)? The RMX just doesn't make it at background music levels.

Part of the reason I picked the QSC RMX over the GX3 were the specs, the filtering options and what looked like better support (QSC has some nice modules for the RMX that you can pop in should anything go wrong--but there is nothing similar for the GS series).

[rrcrain]

Tom,

Problem is wife acceptance factor. In order to get any decent sound at all from the speakers you have to listen at something above a whisper, but unfortunately my wife only wants to listen an extremely low levels (what is it that women want their music at a whisper)?

To some extent, I envy you. I came home one day to find the floor vibrating when I walked into the kitchen. My wife was playing Elvis (her idol) and she wanted it LOUD. Damn lucky she didn't burn out a driver as my amps can produce 300 watts full power and roughly 600 watts per channel peak.

[genek]

To some extent, I envy you. I came home one day to find the floor vibrating when I walked into the kitchen. My wife was playing Elvis (her idol) and she wanted it LOUD. Damn lucky she didn't burn out a driver as my amps can produce 300 watts full power and roughly 600 watts per channel peak.

When I set up our "new" HT in the living room using AR-3a's for the front channels, 2ax's for the rear surrounds and an ms1 for the center channel (still not sure that's going to be the final choice) I also set up direct-to-TV audio so my wife could just use the set for sound because she never wanted to use the old living room audio system (2ax's and her old Sony amp, which I put back into service for a couple of years after my old amp met an untimely end at the hands of some movers). After a few days of listening to the new arrangement, I come home every day and the TV is on mute and the ARs are in play. But neither of us likes vibrating floors and blasting volumes, so no worries about her turning it up too much.

[tysontom]

Tom,

Perhaps this post is out of order in the sense that it relates to amps not ARs. Plus I hate to put you in a corner, but do you have any recommendations? I began this odyssey by rebuilding my old AR3 with much help from Roy C, JohnnieO, you and others. I recently finished rebuilding/redoing an old Dynaco PAS 3X tube preamp which sounds great with the ARs even running an old Dynaco 120 with caps that look ready to go at any minute.

I tried a Crown D150A I picked up at that auction place and it lasted about a week before it quit. On opening it up it looked as though someone had tossed a firecracker in there and the caps that had not blown were about ready to. While it worked the sound was quite good. Having learned my lesson with the Crown I ordered a new QSC RMX 850. Problem is wife acceptance factor. In order to get any decent sound at all from the speakers you have to listen at something above a whisper, but unfortunately my wife only wants to listen an extremely low levels (what is it that women want their music at a whisper)? Does it make sense to go with less power (i.e. Crown D-75)? The RMX just doesn't make it at background music levels.

Part of the reason I picked the QSC RMX over the GX3 were the specs, the filtering options and what looked like better support (QSC has some nice modules for the RMX that you can pop in should anything go wrong--but there is nothing similar for the GS series).

oldguide,

The RMX amplifiers are superb, but at a whisper they have the fan noise that can be annoying. In my audio cabinet, I keep a door partially closed and rarely hear fan noise, but it can be a factor. With the AR-3, any amp is going to struggle a bit because the impedance drops below 2 ohms in places, and this poses a real problem for most amplifiers (certainly not the QSC). You might try to use an Adcom amp; these work well. I used to use an Adcom 5300 with a pair of AR-3s, and it did fine. I still have it, and you are welcome to try it to see if it works, if you wish!

--Tom Tyson

[oldguide]

First, thanks to Tom Tyson for the generous offer and thanks to everyone else for the helpful suggestions. I have much to ponder.

Tom, I will email you re your offer.

But before the folks at QSC get the wrong impression let me second Tom's review of the RMX 850, The sound from it with the AR3s is superb. The words I would use for it are crisp, detailed, expansive and neutral in the sense it adds to coloration to the sound. I think that is what I like about pro amps and why I can see they make a good fit for ARs, because they are designed to be neutral so that the engineers, etc. can then do whatever tweaking they wish. The power on the 850 is a bit humbling. With the gains set at a little over half and my preamp set at less than 9:00 it will fill a room.

I did not notice the fan noise because I had it operating in a setup much like Tom's, but later in a different environment I could hear it soft passages. It is easy enough to block out (at first I thought it was coming from an air conditioning vent) and there are tweaks to add quieter fans for those who want to.

However, for me this has lead to some interesting questions/observations about the AR3. It needs room, both in the headroom and spatial sense. It's not that it needs to be loud--although the amount of power it took from the RMX with no distortion and not even lighting up the clipping indicators was scary. In short the AR3 is not for a small living room, which is what I have. The distance from the speakers to the nearest listener are about six feet and the max about 10-12 feet.

The question revolves more around listening levels and distances, which maybe could start another thread. What levels to people prefer? What do people feel are the optimal distances from listener to speaker?

I found another room to really put the RMX and the ARs to the test and found that ten feet or more seemed pretty good. It also seems to me that the ARs do not like the gain (as opposed to volume) turned down. Maybe it's because these old ears have lost a few decibels in hearing range, but it seems to like to be played at moderate levels, which for someone six feet away is too much.

I also maybe need to do some tweaking with the Dynaco in terms of impedance issues, which is a topic for another forum and not this one.

A note for Roy C--BTW the QSC really likes your mids.