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

[Aadams]

If you have read earlier posts in this thread, you know I felt there was strong similarity in sound to the 9 and 3a, long before I moved the Sat stacks into the same room.  I also previously evaluated the BA/58 against the standard 58s which showed great dissimilarity in LMR sound quality.

Now that they are all together, I have spent hours over the previous 2 days balancing systems and listening to evaluate the difference in sound between the 3a, 9 and the Hybrid 9 to determine if the difference was sufficient to make me leave the Hybrid9 in place, which was not the original plan.

To review, the Hybrid9 configuration is one DSP amp to the stacks and one DSP amp to AR9s with each amp configured as either high or low pass at 400hz.  To listen to the standard AR9 I must simply reprogram its amp to full range mode, but I cannot directly AB the 9 against the Hybrid as I can the 3a.

Following are the distilled impressions of all that I have heard using repeated listening of a small range of recordings with which I am very familiar.

The Hybrid9 has an expansive sound more like a 3a than a 9.

All three speaker systems sound so similar that if you were to enter the listening area from the rear, almost 30ft away, without knowing which was playing, you could not clearly distinguish which without approaching within 6ft. 

In absolute terms, according to taste, the Hybrid9 may sound a little better than the standard 9 but the improvement over the 9 is subjectively marginal and nothing in proportion to the vast improvement that can be had with any AR12” 3way except the AR3a or LST, IMO.

I will soon begin moving the electronics and wiring back to the 58s but just before I replace the Sat stacks I think I will try out the sound of a 4way AR5.

 

Adams

 

[Aadams]

The 4way AR5 is configured and playing, stacked on the 58s.  The more you do this the easier it gets to dial in these sets of bi-amped dissimilar speakers. They are crossed over at 200hz and I think they are balanced but I will listen for at least another couple of weeks before putting the Sat Stack back on the 58s.

The only ever problem with AR5s has been the disappointment of missing the lowest bass when it hits in the music because its low roll off begins around 50hz.  This configuration solves that problem.  You might be able to duplicate this with two powered subs and a natural low roll off but it is easier to take active control and impose a high and low pass at a point where both drivers are working comfortably and more than an octave away from a built in crossover point.

The AR5 tweeters have been sent for rebuild.  Although both of them worked it became obvious they were lacking in comparison to the Sat stack tweeters. I will report further on the 4 way AR5s when I get the tweeters reinstalled.

 

Adams

[Aadams]

At my house, the AR5 and AR3a sound virtually identical in their common range.  

When I started this project over a year ago I was trying to match or exceed the sound of an AR58s.  Over the past two days I have been directly comparing the sound of the Sat Stack with AR5s in a four-way bi amped configuration. The 4 way config uses the AR5 10” woofer as a low mid driver between 200 and 600Hz. Everything below 200hz is carried by the 58s woofer.  

The setup is as follows: 

AR5s are fully functional with new rebuilt tweeters. The late style woofers have resistors installed to bring sensitivity in line with the earlier woofer….  Graphic equalizer is bypassed, Hi control is full and mid control is half.

Sat Stacks, consisting of 6 BA65 speakers……..12 drivers in all, as pictured previously, are on the graphic equalizer set flat except at 1000hz which is 3db down.

The Sat Stacks are sitting directly atop the AR5s which are on a pedestal 12” above the floor.

The recordings are all very familiar, to me, classical and two specific pop vocals that have sections of lyrics difficult to render. 

Conclusion:  The sound is virtually identical if not on a direct AB switch.   This means if you were to walk in the room being acquainted with the sound but not knowing which was playing it would be a 50/50guess.   I have demonstrated, to my satisfaction at least, the expansive sound of the classic AR domes can be duplicated with an inexpensive array of more modern speakers.   The stacks will remain on the AR5s indefinitely.  And, I am very glad I did not sell my AR5s.

One surprise: The AR5 vocal performance is the equal of the Sat stack.  The AR5s are definitely better than my 3as in this area

Second surprise:  The sound spread of the Classic AR domes is remarkable.  They can equal the spread of twelve modern drivers.  I am not talking about power handling but dispersion.  I think this ability ended with the beginning of the ADD series.  I know the 58s cannot create the same expanse of sound as the AR5, in the near field.

Finally, there is a thread in the AR forum about getting the AR sound from modern components.  I can say without reservation this is one way to achieve that.

 

[Aadams]

SatStacks on AR5s with 58s as subs .  Both systems are now on a switch.  It takes about 10 seconds to change the amp settings to compensate for sensitivity.  My Opinion is unchanged They sound so similar that if I avoid looking at a particular switch I cannot tell which system I am hearing from the listening position. 

 

[Aadams]

 

If you have a set of properly working AR5s and a pair of any AR12 inch 3way , ADD through TSW, Edit (or especially an Original Large Advent) you have an opportunity to inexpensively create a more capable speaker by combining the two systems into a 4 way configuration crossed over at 200hz.  You will get the benefit of the 12 inch woofer avoiding the human voice range, with almost all voice originating in the 10 inch AR5 woofer before it crosses over to the wide dispersion mid at 600hz.  It has the clarity of an AR9 with the dispersion of a 3a and its laid-back sound but the lighter touch of the AR5 10inch in the voice band.  I wish I could say I had planned this as part of a genius insight, but it was done on a whim.

Adams

[Aadams]

 I find myself with a lot of listening time available and have devoted a good bit to these refurbed AR5s.  I have had my 5s for five years and as recently as 3 months ago viewed them as a less capable AR3a for the chamber music and acoustic jazz /pop/folk crowd.   My current opinion is AR probably never made a system that sounded better in the voice band and above, including the AR9.  This is just my opinion, but it also means there are not many speakers equal to or better than an AR5 which I would now put above a 3a for quality of sound in the low mid-range, where most musical sounds originate.

Adams

[Aadams]

The AR5a Improved.  Must be bi-amped with external crossover.

 

 

[Aadams]

If you have read previous posts you know I did a same room comparison and established that the Sat Stack compares well against the my 9s and 3as.  Over the last 2 months I have tried to volume equalize the 9s, 5a and the Sat Stack using the 9s as the volume level base line.  The basic procedure uses adjacent listening rooms as follows.

Music source and equalizer settings are identical for all systems

AR5 Tweeter control max

AR5 Mid control is about 75% max

AR9 controls are Zeroed

Sat Stack has no attenuators but is set down 3db at 1000hz 12db per octave slope on an in line equalizer

Listening distance for all systems is about 8 ft

Volume level is low enough to not be easily heard from the adjacent room

This may seem klugey but I have no help in doing this.

 

1.       Set the volume level for the AR9s at 8ft

2.       Set the volume for either of the other two systems until, when walking from one room to the other there is no apparent volume drop

Results: 

On instrumental music of any kind that I have tried there is no difference that I can discern except for the occasional obvious low bass on the AR 9s.

Playing song after song of mostly non-classical solo voice did reveal differences but I don’t know how to describe them.  All three systems sound almost identical.  If the test were blind I don’t know if I could reliably identify them when switched but in the absence of a helper, the best I can do is say the Sat Stack with its more modern drivers seems to have an edge over the others on recordings of solo voice.

Bottom line.  If I lost my ARs I could get back to an AR sound eventually using more modern equipment though I don’t know what I would use for a woofer.

 

Adams

 

[ligs]

13 hours ago, Aadams said:

"Bottom line.  If I lost my ARs I could get back to an AR sound eventually using more modern equipment though I don’t know what I would use for a woofer."

Adams

 

I was a long time subscriber of Speaker Builder magazine. I saw an article by David R. Moran in March 1992 comparing the performance at 24 Hz of four sealed 10" woofers(Allison SW20) with a single vented 10" DRSW10(which later became HSU Research HRS10). In Table 2,  the data show the properly designed single vented 10" woofer is cleaner and can play louder. Later I bought a pair of Hsu HRSW10's and I have kept them and refoamed them and am still using them today. I don't know if other people feel this way but a properly designed subwoofer can produce more satisfying  and palpable bass than a woofer(or subwoofer) that has to be integrated into a single large cabinet with the rest of drivers. Thus experimenting with a separate good quality subwoofer may satisfy the all the bass you may desire. 

George

Quote

 

 

 

[Aadams]

Good article.  Moran’s description of the symphonic bass drum hit exactly describes what I hear easily on my AR9s and only slightly on my other systems.

I believe that separate powered sub woofers can produce bass far lower than I practically need for music.   

The problem with powered subwoofers for me has been my inability to make them integrate pleasingly for music playback in stereo.  I think I could have eventually found a solution for my hybrid system by shopping in the $1000/unit range but by then I had stumbled upon a passive solution in the AR58 cabinets.  If I ever do move to powered subs I will still use a DSP amp to set the high pass frequency and bypass the subwoofer crossover.

Luckily, I won’t have a problem so long as I don’t outlive my speakers.  For the foreseeable future I can still find plenty of AR 12” to serve as passive units in the event I lose mine.  Still, it would be nice to experiment with a couple of powered subs but I am already out of space for systems and the cost for new, just to experiment, is just not reasonable IMO.  I don't have family that is remotely interested in owning any of this stuff, if given to them.  I am in a bind until I rationalize my way out.

Was that the entire article? It had an abrupt ending.

Adams

 

[ligs]

 

 Here is page 3 of the same article. BTW, I am using a dedicated subwoofer amplifier for my subwoofer(s). https://www.parts-express.com/dayton-audio-sa1000-subwoofer-amplifier-rack-mountable--300-811

Dayton Audio SA1000 Subwoofer Amplifier Rack Mountable. Model SA1000. It has a variable 24db/oct low pass crossover and a parametric equalizer to fine adjust the frequency response. 

 

 

 

George

[Aadams]

Are you using two of these with the NHTs?  

 

 

 

[ligs]

In my main listening room I am using Dayton SA1000 with a pair of HSU TN1220's subwoofers which have received a rave review in High Fidelity magazine.  

http://www.gammaelectronics.xyz/audio_1998_Aug--hsu.html

Also I am using my pair of NTH 1259's as the woofers of my 92 db satellite speakers(JBL 127 H1 and Dayton RST 28 A-4). They are flat to 32 Hz and then dropping off rapidly in the room. Therefore I need to use HSU TN 1220 for the last octave. 

 

In my family room with Samsung smart TV, I am using a pair of Infinity Reference R162's and a pair of HSU HRS10's  driven with a Dayton SA500

Let me try to upload the third page of the article mentioned before. 

 

George

[Aadams]

On 10/16/2018 at 3:23 PM, ligs said:

lso I am using my pair of NTH 1259's as the woofers of my 92 db satellite speakers(JBL 127 H1 and Dayton RST 28 A-4). They are flat to 32 Hz and then dropping off rapidly in the room. Therefore I need to use HSU TN 1220 for the last octave. 

Thanks for the page, without which I am not sure I could have decoded the above statement.  What I think you are saying is the 1259s are flat to 32hz and the HSU goes below that.  At first I thought you were saying the JBL 10" was flat to 32. Do you have a shelf on the JBLs or do they just roll off to the 1259s?

The subs you have are no longer available except used and finding matched, used pairs is near impossible and few sellers will ship.

 

 

 

[ligs]

Yes, 32 Hz refers to the combined (connected in parallel) response NHT 1259 and satellite with JBL 127H1. NHT 1259 has an in-line low pass passive crossover at around  100 Hz as in NHT 3.3.

The satellite is about 2 ft away from the backwall and  just sit on the boxes containing the sealed NHT 1259's.  

Madisound used to sell a version similar to NHT 1259 but is no longer available. http://www.madisound.com/pdf/MAD1259.pdf

 

George

[Aadams]

3 hours ago, ligs said:

NHT 1259 has an in-line low pass passive crossover at around  100 Hz as in NHT 3.3.

The satellite is about 2 ft away from the backwall and  just sit on the boxes containing the sealed NHT 1259's.  

Does the JBL127h1 have a cut freq or is it allowed to roll off below a 100Hz?

Aadams

[ligs]

I have a very rough idea about the frequency responses measured in my room with the help of  a Radioshack analog SPL meter and Stereophile test CD. The response cures will not be comparable to any other  lab measurements.  These curves are not calibrated and are meant to serve as a comparison purpose.  The microphone is placed about 1 meter between the JBL woofer and tweeter.

 

Keeping that in mind. It does appear that JBL 127H1 satellite without NTH 1259  begins to roll off  below 200 hz. This is due to the very small sealed box volume , a 50 ohm resistor across woofer and the placement of the satellite without room boundary reinforcement.  Combining with NHT 1259, the entire bass region (red and green lines) becomes flatter and extends at least to 32 Hz. As shown.

 

George

 

 

[Aadams]

Most of this thread has been about the speakers atop the stack so this post is a twist that focuses on the AR58s sub-woofer.   As you an see in the photos the 58s are raised 1ft above the floor but are also inverted, with woofer on top, and placed square against the wall within 2 to 3 inches of the woofer frame.  Several position configurations were tried, following the Roy Allision research regarding woofer placement and this configuration yields the smoothest bass of all up to 200hz where the woofers are low passed.  Mid bass peaks are gone and perceivable room resonances at the listening position have vanished.  The curve for this position shows a rise, which is present, at the very lowest response range but I have yet to hear a recording where it is a problem. 

I also got lucky because the Allison study only predicts effects from first reflection from nearby surfaces and not additional walls as you would find in an actual listening room but it gives a good start.

[Aadams]

This post is about the AR1w but first I want to say something about the AR9.  The only AR9 I have ever heard is the original vertical.  The feature that always strikes me when listening is the bass output, but I don’t mean the depth or prominence. If the speakers are installed within the very liberal guidelines suggested by AR you are rewarded with automatic, practically flat bass to 200hz.  The beauty of flat bass is, voices seem to float above the low frequencies with zero coloration introduced by bass peaks.  I mention this because I now realize that any AR12 inch that employs a single front facing woofer is subject to coloration in the voice band because the woofer performance is almost always compromised in order to keep all the upper band drivers facing the listener.  This may not be true in a lab but given the usual limitations of home listening spaces it is a general fact.    

In the case of the AR3a the best position to achieve optimal and practically flat bass performance is to mount them flush in a wall or book case.   I can’t do this at my house.  

Thankfully, Roy Allison left a body of research that points to other ways of achieving practically flat bass response by using modern electronics and the AR1w.

I was recently reminded by one of our forum experts that inside every AR3a is an AR1w.  I purchased a long idle pair, restored them to life, disconnected the jumper and began testing them as alternatives to the AR58s as a passive subwoofer.

I have included images, below, of the left and right channels.  Using the 58s as stands places the 3a woofers 45” above the floor, almost equidistant between ceiling and floor.  I originally had them installed with baffles against the wall, but the room gain caused an annoying peak in the 50hz range when playing some pop music with three note bass lines.  The solution was what you see in photos and is a solution which I rejected when using the 58s woofers in the same position  directly one foot lower on the wall.   Room boundaries cause crazy phenomena with bass.

The 3as have been turned to correspond with the fig 7 below of the Roy Allison paper. 

What I am experiencing now is almost like the voices floating over the bass that I hear with the AR9.  What I thought were clear vocals before are even clearer now.

The long term plan is for either the 58s for 3as to move to another room but while they are here I will have the tweeters rebuilt in these 3as, then biamp them alongside the AR5s with the 58s as bass units.  The intent is to determine if the voice performance of the 3a can be made to mimic the AR5 by splitting the high woofer octaves from the low octaves.

[Aadams]

I couldn’t leave well enough alone.  As I listened to this new speaker arrangement I kept running across occasional rock and pop vocal recordings that had an annoying peak in the sub 125hz range.  I had been all over the gain controls and was convinced this was purely a question of positioning within this room.  I finally moved one woofer about 2ft along the wall and reversed it to face the opposite corner which reduced the low bass peak but it sounded too lean. In desperation I decided to return to flat settings on the equalizers and recalibrate everything by pulling out the headphones and refreshing my memory of how this music sounds with zero room reflections.   In the process I relearned what flat bass sounds like and this;  that most of the pop and rock vocal music that I listen to does not have very deep or prominent bass.  When set properly the bass almost never blurs the vocals nor is it so loud that the vocals are overwhelmed.  In the end, all I needed was even milder equalizer adjustments to get very close to the headphone sound. 

I know this is subjective. If you like bass slam, listen to power chords and shredding guitars then you won’t be interested in what follows but, if you really want to hear all the words that are being sung, especially in classic rock and pop, then put on your headphones to adjust your system and get an easy improvement in both imaging and clarity.

You need merely decent headphones and these songs.

The original “Astral Weeks” by Van Morrison.  This is almost all acoustic with subtle textures easily obscured by mid bass peaks.  Morrison's vocals can be very difficult to understand on speakers but are completely intelligible on headphones.

Original “Won’t get fooled again” by The Who.  You can hear every word on headphones.  The bass line is surprisingly not prominent on headphones but, through 12” ARs, it is easy to have heavy mid bass that blurs the vocals

“Paradise by the dashboard lights”.  Every lyric word as well as the baseball base stealing metaphor can be heard clearly through headphones.  It is easy for the mid bass to obscure the male vocals in this one and blur the female voice.

Other tough ones are "Born to Run" with the E Street Band and "What would you say" by The Dave Matthews Band.

The change was so stark on some very familiar songs that I wasn’t sure I still had the low bass that I want when it exists in the recording.  To reassure myself, I played some classical recordings that I know have low bass and all is well.    

 If you can get your system to play these songs clearly then everything else will sound good.  Your perception of bass may change. 

    

[ligs]

" In the process I relearned what flat bass sounds like.   In the end all I needed was even milder equalizer adjustments to get very close to the headphone sound.  What I learned was most of the pop and rock vocal music that I listen to does not have very deep or prominent bass.  When set properly the bass almost never blurs the vocals nor is it so loud that the vocals are overwhelmed .

Original “Won’t get fooled again” by The Who.  You can hear every word on headphones.  The bass line is surprisingly not prominent on headphones but through 12” ARs it is easy to have heavy mid bass that blurs the vocals"

Well said! Here is an in-room  frequency response of NHT 3.3 . Some people describes it sounds like a pair of headphones and it has excellent vocal clarity. The vocals from 100 hz and up come from the front drivers while the bass from the side mounted 12" woofer(also know as NHT 1259). My interests in 92 db satellite speaker and passive stereo subwoofers with 100 hz crossover were inspired by NHT 3.3. 

[Aadams]

Ligs

Thanks,

It is a journey with no definitive answer. 

Adams

[ligs]

I used to be a research scientist so I am used to pursue a goal for a long time with occasional breakthroughs. As long as we are learning something new and still having fun then we ought to keep going. 

 

George

[Aadams]

This is a comparison of a refurbished AR3a vs AR5.  It is a mod and tweak topic because both speaker systems are bi-amped with a common bass system provided by an AR58 crossed over at 200hz. 

Except for impedance both systems have identical dome mids and are crossed over from mid to woofer at around 500hz  for the 3a and 600hz for the AR5.

The AR5 has original Compulytics while the AR3a has all new NPEs in place of the original ICC wax caps.

Both speaker models have rebuilt Chris tweeters.

All speakers still have potentiometers,

For this comparison:

Tweeter and mid controls were set very close to identical.

Electronics and sources were identical

Both systems were sitting adjacent at a listening distance that varied between 5 and 7 feet and volume matched within 2 seconds after the switch.

There were two listeners.

You ask, “What is he up to now?”   Answer:  To find out if an AR3a can be made to mimic the sound of an AR5 on human voices. 

Result:

Short version: An AR3a can sound virtually identical to an AR5 in rendering human voice, which is contrary to many opinions expressed over many years on the CSP.  You can Google it.  

Long version: I was among those who thought the 3a was weak at presenting human voice.  My impressions were gained through direct comparisons between my totally original 3as and AR9s when playing pop/rock vocals that are difficult to understand.  (Examples below).  Additionally, the 3a seemed to always have a “dark” quality that made voices of Gordon Lightfoot, for example, and Allison Kraus a bit husky and veiled.   The only person on the CSP, to my knowledge, who insisted the 3a was as good as the AR5 at voice was Tom Tyson @tysontom but even he specified the special conditions where he knew this was true or otherwise there could be problems from reflections or interference.  Edit: I finally found the quote:

On 4/28/2018 at 12:04 AM, tysontom said:

It also occurs to me that if you are mounting your AR-3a on a stand or table (above the floor but back against the front wall), your AR-3a will be susceptible to the "Allison Effect," a boundary-caused dip of several dB as the reflection from the wall behind the speaker (and the floor) interact with the direct output of the woofer and cancel (null) certain frequencies to some degree, usually around 300 Hz or so.  This could impact intelligibility at those frequencies, of course, and the way to fix this problem is to mount the AR-3a flush with the wall or in a bookcase flush with books around the speaker so that the woofer sees a true 180 solid angle.  It's not always easy to do it that way!

With the AR9, the idea was to get the woofers to operate close to the floor-wall boundary to get maximum reinforcement and minimum boundary dip, such as the wall and floor, and to limit the pass band of the woofers for smoothest response.  Therefore, with side-mounted 12-inch woofers operating up to 200 Hz, there had to be a lower midrange driver (requiring a 4-way configuration) to handle the mid-bass frequencies.  This also allowed a higher crossover into the 1½-inch midrange dome to improve its power-handling capability, and so forth in the design of the AR9.  It was definitely a step forward in design.

The AR-3a has been criticized in the past for its somewhat "heavy" sound, and some of that problem was due to a crossover issue during the changeover from the Alnico woofer to the newer ferrite woofer in the 1969-1970 time frame.  Also, the relative balance of the midrange output to that of the woofer seems to give a slight sense of heaviness, but it is very minor. 

 

What I have discovered at my house is the AR3a is easily the match of an AR5 in vocal rendition if you do these things

1.Remove bass peaks below 200hz.  Not easy to do with a 3a unless you mount it flush in a wall or book case.  The last octave of bass must be flat or rolled off as perceived at the listening position. This is not a problem with the 5 because it does not naturally yield much of the last octave unless forced.  If you place either speaker in a position to emphasize the lowest frequencies using room gain you will likely make compromises that interfere with the perception of voice, but the effect can be much worse with a 12 inch woofer.  My solution was to make both systems use the same bass sub-system which I have already optimized for this listening area.  The 3a woofer as a LMR is rolled off 24db octave below 200hz.

2.   Tweeters aren’t required to render a clear voice but once the bass is worked out voices will sound dull without tweeters that work well.  For either of these systems that means rebuilt or HiVi.  Even if they pass the paper roll tube test, I promise you, your UNrefurbished, 50 year old, ¾” AR domes are defective. 

3. Asking a speaker to render Louis Armstrong, Ella Fitzgerald, Sarah Vaughn etc. is not a challenge.  The mixes were set up to make the voice the prominent feature.  A real challenge is to play some of the following and understand the vocals.

- Elton John “Goodbye Yellow Brick Road”

- Elton John “Saturday Night is Alright for Fighting”

- The Who “Won’t Get Fooled Again”

- Dave Matthews - “What Would You Say”

- Bruce Springsteen and the E Street Band “Born to Run”

- Bruce Springsteen and the E Street Band “Rosalita”

- Gordon Lightfoot “The Summer Side of Life”

-Van Morrison – “Astral Weeks”

-Cowboy Junkies- "New Dawn Coming"

All these songs have lyrics that are clearly understandable on well sorted systems.  You don’t have to like the music but if you can’t hear the words in these songs on your speakers you are missing a lot of musical detail in the recordings you do like.   In my comparison the 3a easily matched the AR5 in both timbre and clarity of vocals.

By-products of doing this comparison: Imaging

Bass interferes with imaging.  Remove the bass as a problem and imaging blooms.   The 3a and the 5 were conceived in the days before imaging was a feature but don’t believe it if someone tells you they can’t image.

Adams

[Aadams]

The AR5a is no more.  The AR58s subwoofer has been replaced by an unjumpered AR3a making the new system an AR-51W. In the subwoofer role, there was no perceivable qualitative difference so the combos were chosen based on wood grain. 

The 58s is now mated to another 3a to become an AR-358, to be operational after a tweeter rebuild.  This one will be used to compare the sound to an AR9.  This is NOT about winners and losers but differences.