AR Bi Amp Hybrids (ActiveXover Stacks) CR65, AR581w, AR51w, AR358s, AR98T

[Aadams]

Occasionally the question arises as to which AR speaker sounds the best. Of course, the answer is a subjective judgement but if one reads the product literature from the classic period, a stated goal of AR was to make their speakers sound the same.      

The graphs above, taken from the 1975 product brochure, show the AR5, 3a, LST and LST2 will all sound the same, above 500hz, to a listener positioned, in relation to the speakers, as depicted in Fig2

. 

Below 500hz, they will also sound the same except at lower frequencies where woofer size and room boundaries affect bass performance.   Additionally, if the Allison guidelines for 2pi placement are followed, all these models can be made to sound indistinguishable to the limits of their performance capabilities.

The graphs also apply to the ADD dome systems and even to the AR9 Vertical series, though the area of uniform power response of the Verticals was intentionally narrowed.  

Beginning with the AR3a and ending with the AR58S, all AR speakers that used dome mid-ranges can be made to sound the same because the drivers are fundamentally the same units, only modified in appearance and sturdiness.

 

The Main Differences: The top-of- the-line speaker of each generation made it easier to achieve deep flat bass performance in a home listening room.  The LSTs could be placed against a wall, rather than in it, as required by the 3a and 11. The AR10pi had circuitry to achieve 2Pi bass output without regard to boundaries.  The AR9 and AR90 yielded near automatic, very deep, flat bass if placed asymmetrically against the narrow wall of a rectangular room.  The 91 and 92 had their woofers positioned higher off the floor with additional circuitry to give pretty good results when placed on the floor near a rear wall.

All these speakers can be made to sound the same or practically the same above 200hz, if their placement is identical with respect to the listener as suggested in Fig2.

Technically, there is no best sounding AR speaker from the roughly 15-year span in question. There are only differences in the amount of futzing around with placement, level controls and electronics required to achieve the sound that pleases you.

[Aadams]

I am putting this here because it is not speaker specific. 

https://www.linkwitzlab.com/AES-NY'09/The Challenge.pdf

Above is a link to an interesting AES paper from 2009 entitled

"The Challenge to Find the Optimum Radiation Pattern and
Placement of Stereo Loudspeakers in a Room for the
Creation of Phantom Sources and Simultaneous Masking of
Real Sources."

According to the author, one of the big impediments to finding the optimum setup for listening in the home is lack of quality live recordings.

For example.." Far fewer recordings capture a realistic
sense of space. They are mostly found amongst classical
music and jazz, which are frequently recorded in their
normal venues. The use of spot microphones often
introduces artificial sounding spatial effects in these
recordings. For example, the solo piano or violin
becomes too large and close. Instrument groups slide to
the center when it is their turn. Such distortions and
temporal changes in spatial presentation are readily heard."

 and later ............"This reference must be the live performance, our
perception and memory of it. Thus the listeners in the
proposed tests should have familiarity with unamplified
sound, with live acoustic music. Also the human voice
in different environments, single or in groups, is
familiar to everyone and recordings of it should be part
of the listening tests. "

I prefer recordings of live venue performances and good ones are indeed difficult to find.

 

 

[Aadams]

Wide dynamic range music recordings seem to always involve percussion instruments at the highest peaks of loudness. These are some examples of accessible, non-esoteric works recorded with sufficient fidelity to span 12 to 15 decibels between the softest to loudest moments. 

  

[Aadams]

This post is about using silence to increase the power requirements of your system. 

Acoustic music thrives on soft, intimate moments and large scale acoustic music, such as Classical, thrives on the contrast between the very soft and the very loud moments.  The dynamic range of Classical music provides the practical test of power needs for an audiophile system and from 1980 to roughly 1999 the most reliable source for audiophile level orchestral recordings was Telarc.  The dynamics and sound presentation of Telarc were never equaled, in my experience, though a couple of labels, Decca and Phillips, occasionally came close. 

The dynamics of Classical music range from ppp to fff, softest soft to loudest loud.  The loudest percussive moments have provided the tests for audio systems, such as the cannons in the 1812 Overture that took Telarc to prominence.  The fff has been conquered by digital recording but the delineation of volume between p , pp, and ppp between instrument while maintaining concert hall perspective is rare. 

In a concert hall the softest string and wind solos can linger near and then vanish into silence in the same piece of music that harbors thunderously, loud moments.  Even Telarc struggled with this and usually made the softest instruments sound a bit too big, too near or too loud.

There is a new class of orchestral recordings that push the softest passages down near the noise threshold of digital, which reveals layers of texture and instrument groupings that enhance the realism.  The music gets so low that the volume must be turned up to hear the music even in a normally quiet listening space.  When you turn up soft passages the loud passages are even louder and possibly doubling or quadrupling your normal power peaks.

All the recordings I have found with this type of sound engineering are from three labels and not consistently across any one label, BIS, Naxos and DG, all since 2005 and all except BIS before live audiences.  

Here are some examples.

[Aadams]

This is the widest dynamic range music recording I have ever heard that did not use special effects. Performed live 2013.  Beautiful performance, beautiful recording of The Firebird.  You will need a silent listening space to hear all the music.  There are several 12- 15db peaks, almost all in the last eight minutes.

 

[Pete B]

I see that you mentioned the Linkwitz Challenge from 2009 several posts back:

https://www.linkwitzlab.com/AES-NY'09/The Challenge.pdf

and you probably know that he promotes a dipole radiation pattern in home listening

environments which significantly reduces side wall reflections.  I have a lot of respect

for SL but I don't think that his preference has ever been proven.

In fact his challenge was tested out and the Orion ($9000) came in last, I have to dig

deeper into this as there does not seem to be a clear writeup of the event.

On the other hand many audiophiles swear by his designs.

 

[Aadams]

On 3/6/2022 at 7:38 PM, Pete B said:

and you probably know that he promotes a dipole radiation pattern in home listening

environments which significantly reduces side wall reflections. 

Yes.  I  remember reading somewhere that his preference was for a 4 way dipole using active crossovers and an amplifier on every driver, with very specific placement and somewhat large minimum requirements for room size. I have no doubt they could sound good. 

In my statement above I was referring to Section 5 on Test Recordings. Linkwitz seems to have come to the same conclusion as Villchur and Allison that live performance is the standard by which loudspeakers should be compared but there is a conundrum which is explained in paragraph 2 of that section.

It can and has been argued that it takes better recordings
to improve the loudspeakers, but it also takes
loudspeakers to know which recordings are better [7,
Chapter 2]. The process can become a circle of
confusion if there is no sonic reference outside of it.
This reference must be the live performance, our
perception and memory of it. Thus the listeners in the
proposed tests should have familiarity with unamplified
sound, with live acoustic music. Also the human voice
in different environments, single or in groups, is
familiar to everyone and recordings of it should be part
of the listening tests

 

 

[Aadams]

The case for 40hz.

If you don’t listen to recordings of Dubstep, Hip Hop, Large Pipe Organ, or special effects movie soundtracks, your chances of playing any recorded music containing a bass note below 40hz could be close to zero.

There are only 30 musical instruments that can sound a note below 40hz.  Most of them are esoteric, near unicorn status, and are occasionally used for the odd solo part in large orchestras or almost exclusively in small wind ensembles.  For example, a contra bass flute almost never appears except as support for an all flute ensemble.  When was the last time you heard recording of a full range flute septet? 

There are only two commonly used instruments that can sound a musical note below 40hz…..the Piano and 5 string electric bass. 

A concert grand piano has a 27.5hz A string.  The five string electric bass has a 30hz B string. 

If you listen to Jazz/Rock Fusion, it is not uncommon to hear the 5 string bass sounding below 40hz but the most commonly used bass guitar is the four string, which is standard tuned to 41.5hz and is sometimes downtuned to around 38hz to avoid an open E string at 41.5hz, the same as the standard Double Bass/Upright Bass used in Acoustic Jazz groups and Symphony Orchestras.

Jazz and Classical piano virtuosos, playing solo, frequently hit notes below 40hz but when supporting a group, the piano generally stays away from string bass territory to keep from blurring the bass line. 

If you don’t listen to Solo Piano or Jazz Fusion there are virtually no instruments used in any modern music genre that play below 40hz.

In every wind and stringed musical instrument, the fundamental frequency of any note triggers as series of higher harmonics and overtones that define the instrument, creating a unique sound signature.     Usually, the fundamental frequency predominates but as frequency descends below 40hz, our ability to hear low frequency sounds diminishes and the second harmonic tone becomes prominent.    So, when the hammer strikes the 27.5hz A string on a grand piano, you may possibly feel the 27.5hz fundamental but what you hear is the second harmonic at 55hz and the overtones from many higher strings that have been triggered as sympathetic vibrations. The brain perceives the presence of 27.5hz even though the harmonic series beginning at 55hz predominates. So a speaker limited to 40hz or even 50hz can sound strong at 27.5hz.   

[Aadams]

I have been trying to find a better or perhaps best recording/performance of Saint Saens 3 (Organ Symphony) and came full circle to my previous favorite in a different form.  Out of four different orchestra recordings I have a new top 2.

 

[Aadams]

I purchased the above 2004 release of this 1981 recording , which contains mostly organ tracks, for the orchestral music alone. I did not realize until recently the bonus pipe organ tracks contain some outstanding demonstration quality music that will challenge 12 inch ARs. Specifically, the Couperin “Chacone in G” and the Widor “Toccata Symphony 5” are first class recordings and performances.

There are hundreds of recordings of the Widor work but it is hard to find another with equivalent quality of presentation.  To hear what I am hearing you will need a CD, SACD or a lossless FLAC or ALAC file.  The AAC and MP3 versions are not good enough. Vinyl is an option since all the music on this cd was originally mastered for vinyl but issued as two different recordings.

 

[JKent]

On 12/14/2019 at 7:40 PM, Aadams said:

The AR classics with potentiometer or lpad attenuators, as opposed to later series with 0db attenuation settings, are difficult to balance.  If you want to hear a classic at it’s absolute best the attenuators must be adjusted to bring the corresponding drivers of the stereo pair into exact loudness balance.  In the case of the 3a and 5 the mid-range attenuator is the predominate factor in determining whether the sound is focused and centered as opposed to sounding vaguely centered and with a shifting soundstage.

I have found an easier way to balance attenuators that employs a 10 band equalizer.

For a 3a or 5 set the sliders to full minimum on every band except the 2k band which should be set to maximum.  This provides max emphasis at 2k which is in the middle of the mid range driver bandwidth. 

1. Assuming you already have the attenuators at a loudness setting that pleases you:

2. Play a mono recording with vocals, I like Glenn Miller or early Beatles for this, and listen within 3-4 feet to judge if the image is centered between the speakers.  Toe them in if you can.  Adjust the attenuators until the image is centered in the near field or at the listening position or both.  

3. Return the equalizer to its normal setting and reposition the speakers. You are done.

Adams

 

 

[Aadams]

This is good info. I plan to have a hi res equalizer BEFORE this conversation occurs.

On 10/16/2022 at 11:51 PM, JKent said:

[Aadams]

 

Sometimes you can’t make the music louder than the noise and keep it enjoyable.  This post is about silence as a musical effect and degradation of the musical effect by noise.    .

As an example, the most popular classical musical work in the English speaking world, according to annual broadcaster polls, is “The Lark Ascending” by Ralph Vaughn Williams.   It is a dreamscape featuring a solo violin, against a lilting string orchestra accompaniment, evoking scenes of dewy grassed meadows in early morning sunlight.  Rewritten in 1920 , for a small orchestra, it was expected to be heard live in a quiet performance space where visual cues combine with sound to enhance the delineation of soloist and orchestra.  There are two performances going on, the delicate violin out front and the larger group behind needing to be heard while never upstaging or engulfing the central voice. Most of the recordings before the digital era failed to capture this effect, primarily because, before digital, all recording mediums had inherent noise that was as loud as the softest violin note.  I know of perhaps one remastered analog version that is an exception.

The featured solo violin in this work often plays against silence.  In newer DDD recordings, like the Naxos, the violin can be heard against a dead quiet background when listening from 2 meters, even with high gain settings, while the string accompaniment remains in proportion and never overpowers the solo violin.  

In older recordings captured in analog,  the violin is somehow boosted to stay above the noise floor but this causes the sound of the orchestra and sometimes the solo violin, to get too large and out of proportion;  Not enjoyable if you have an expectation of better realism.   The ARGO ADD recording (above) is of this latter variety but its deficiencies, from an audiophile perspective, have not stopped it from being one of the two most popular versions of this work in the Classical Music Broadcast business.  The other recording is even older.  I am sure either sounds ok in a car moving over the road.  

The work ends with about 2 minutes of solo violin.  If you are listening to the Naxos performance the violin gradually dissolves into silence near its highest musical pitch.  In the ARGO you can hear the solo violin against a low pitched hiss that is the inherent noise of tape recording in 1972. The hiss is always present when the violin is playing alone.

This music demands silence for you to be drawn in completely.  The loudest sound at your listening position should be your tinnitus or breathing.  If you hear amplifier hiss/fans, appliances, lawnmowers, household activities or HVAC vents , the effect of silence is wasted.

Recordings of “The Lark” are numerous and all of them in some way serve as a practical noise floor test for home music systems and listening space. There are other examples.

 

[Aadams]

On 5/18/2019 at 6:41 AM, ligs said:

Did you notice any difference in the bass quality of the AR woofer driven through the crossover vs driven directly by the amplifier?  Without the resistance(perhaps as high as 0.8 ohm) from the crossover inductor,

Ligs

The answer to your question is yes.  I have been using a 58s as the woofer for about 2 years and went back to the direct wired 98ls woofer on the floor with baffle perpendicular against wall in the same position as the 58.  The difference is an improvement and quite noticeable.

[ligs]

It is good to know.  I felt the same way when I A/B AR 3a with vs without the low pass crossover(2.8mh/150uf).

George