Building a Room Full of Balanced Harmonics

Greetings Zonees

Here are the pictures of how Sonic got the Cardboard Tubes into the system nicely:



There are two 4” wide rolls of ‘burn’ in each of these tubes. The Left one has the rolls about 10 inches from either end. The Right one has the rolls about 14 inches from the two ends. In the background you can see one of the Tubes in the front corners.



This is the Left corner Tube moved into the room for photography (could not get the flash right). There is only one damping roll in each of the corner Tubes positioned flush with the top opening.

The result is improved control with a slight dryness. Promising.

Now if Sonic put two damping rolls in the corner Tubes, the trebles disappear and the sound shuts completely down so all I get is a small hifi soundstage with clarity but no realism.

What am I looking for?

First, Sonic has been in heavily damped rooms where the BOO! is more like BUH! and it is an effort to get any projection in the room. Actually I cannot get a sense how big the room is. It is just a tight BUH! with no overhang tail. The sound stop almost before it leaves the throat. Not what Sonic is after.

In very live rooms the BOO! goes on and there is often shifts upwards. BOO!ooii. What I hear is often a “room recoil” where we get BOO!uh! The “uh” is the pressure wave coming back from the live surfaces of the room.

In these live rooms, Sonic can get the size of the room but the recoil muddles up transients. And the room goes on if I hit the Pause button on the CD player, not an echo but the recoil.

I am looking for a BOO! that stops tight but the room gives not a recoil but a slight “glow” to show that the BOO! is uttered in a balanced room. The “glow” is not an echo and there is no impact to it. The “glow” is also balanced and warm.

There is a recital hall in my town that has this characteristic and once I heard live unamplified music there Sonic said “yes, this is what I want my room to do!”

Sonic is getting there. I still have some imbalance tonally but there is no upward shift.

Was listening to:

Kind of Blue (Miles Davis, Columbia), Laughin’ to keep from Cryin’ (Lester Young, Roy Eldridge, Harry Edison/ ), J S Bach Sonatas for Violin and Cembalo (Kuijken, Leonhardt, Deutsche Harmonia Mundi), Haydn Keyboard Concertos (Staier, Freiburger Chamber Orch), Tschaikovsky Symphony Nr 5 (LSO, Karl Bohm), Dvorak Music for Violin and Piano (Harwood and Tomes, Helios)…this last one sounded wonderfully realistic.

Next I may need to balance out some over dead areas and shift the materials to other places in my room to increase damping in those areas, all the while understanding that the Tune needs to avoid any deadened acoustic spaces. This is like what Michael said about balancing the air pressure in a car’s tyres for a smooth ride.

The first step took place 4 days after I got the Tubes set up. By then I had got over the unease caused by being too used to an overly live acoustic environment and then switching to a more controlled one.

To remedy the imbalance, I tightened the three FS-PZCs a bit. How was this done and how tight were the bolts set? Easy…first really dehumidify the room for a significant time. Then I slipped the thinnest piece of paper I could find (a news magazine page) under a bolt and tightened it till the paper was just gripped firmly. Not tightly. Firm but I could pull the paper out without tearing it. With the paper removed, the bolt was then tighten further by about 1/16 of a turn tighter so the tuning bolt is lightly pressing on the wooden face of the FS-PZC. This was done on all three FS-PZCs in the room. The tightening allowed control of the BOO! but gave more sparkle to overcome the damped sounding character.

Getting even closer…thinks Sonic. I need to next think higher, that is controlling the reflective surfaces higher in the room.

As the room is coming under control and settling, Sonic is looking at the sources.

Michael, how do you suggest I tune this?



The turntable is kind of flimsy and the bottom section is a moulded plastic box with four rubber/elastomer damped feet in the corners. It had a 6 lb slab of metal on its base to give weight or stability but I have removed that.

How should I start tuning? Harmonic Springs under the base and remove the rubber feet? Or Harmonic Feet? Sonic understands Michael’s view that springs are good. For a turntable we should have only one compliance, meaning Sonic is worried when I see sprung turntables sitting on top of sprung platforms. The whole thing is just put together and if the compliances are not designed to work with each other it is bad engineering. The two compliances will have different frequencies that may resonate/build with each other and give an exaggeration at some frequencies which worsens the system’s performance.

So IMO, if the turntable has no springs, then springs underneath are an option. A spring-isolated turntable should go onto a rigid platform unless the two compliances have been designed to work together.

Sonic

Hi Zonees

If I could get my hands on a couple of hemlock clamprack shelves Sonic could double up the top shelf and separate it from the one immediately below with Harmonic Springs, then set the turntable on it. The TT could sit on Harmonic Feet. Just ideas - wonder what Michael thinks of tuning the Audio Technica.

Also I have found that the present treatment of the window (see my Feb 15 post) is about right. Add more ETs, and I get more control on the low end but there is a higher overtone starting to appear. Working on this, will discuss the progress.

Sonic

Hi Sonic

The TT tops that I make use a different harmonic spring. They are a higher degree of compression. The regular Harmonic Spring is a little on the low side and if you do use them you will want more between the shelves more than likely.

Hi Zonees

Michael said that "stereo and live music are two different events..." or close to that and he is right (again).

I been listening to this wonderful ECM recording "Making Music" by Zakir Hussain, Mc Laughlin, Hariprasad and Gabarek. The recording is very well done but bears no spatial semblance to the sound in the studio.

In the studio, the four performers are separated apart in each corner of the room surrounded by acoustic dividers. They are in effect at four corners of a square. On the recording the performers play on a stereo plane with the percussion slightly back and the guitar, karnatic flute and saxophones forward. The performers face the listener like they would in a live concert and the ambience rolls past the listener to the rear.

But look at the pictures of the studio -- the players are not in line, they face each other and the ambience rolls nowhere since there is no "forward" dimension.

So we have a physical layout and a soundstage reality that are completely different. Question: which is the real sound?

Sonic

Hi Sonic

Truth to me is this. It's when the soundstage becomes limitless and without holes. At this point I know I am approaching the recordings "fill". This is the point of technical saturation on the recording storage. A sign of this is being able to hear the entire space of the microphone pick up pattern. This is almost always the size of an entire room and when several mics are being used you can feel and hear energy entirely around you and a flow of movement that happens off of a mic signal that has an affect on the entire stage. You don't feel like something starts and stops as much as a feeling of "I know it's over here but I can since it through the whole room". Studio effects mixed in with live instruments are usually a great way to hear this as you can see the start and stop of the effect but the live instrument keeps going as it uses the recording room as part of it's sound. Even with a lot of dampening in the studio you are able to hear the instrument and the material together. The opposite is also true when the effect is a general one that fills the recorded space and then you can hear a iso booth or smaller space mixed into it.

Real though as in a live instrument sounding like a recorded one. The live one will fill the room's limitless reaches and use all space to be part of the sound whereas a recording is far less dynamic. the recorded one doesn't know how big your room is and if you are limited to your room size you may not be getting the whole recorded picture.

I always like it when someone discovers staging and gets out of the box. Sad that many only listen to very simple recordings and never get past their personal fight of tonal hints or placement that is dictated by componentry instead of the recording. Serious classical and rock listeners tend to have bigger sound stages than jazz folks (simple jazz that is). So many audiophile recording are made so simple that you don't even really think of a complicated stage that is full. that is until you put a piece of rock on or a big classical piece. That's when a lot of these guys systems fall to pieces and give you this very squeezed and distorted sound when in reality these types of recordings are wanting to fill a full stage.

Hi Michael

I think there is something about those who only listen predominantly to small ensemble jazz. The want to reproduce a small club feel and given the 3 or 4 instruments plus the aim of getting focus, you get a recipe for creating a small soundstage. Also particularly old jazz records from the late 1950s had saxophone in the LH speaker, piano in the RH speaker and bass and drums somewhere in the middle. You will try to pull the stage inwards to avoid needing eyes on the side of your head to see the R and L images.

What Sonic is thinking too is when I asked about the ECM Zakir Hussain CD ...which is reality - the four musicians sitting in the corners of the studio behind baffles or the straight line mixed down soundstage?

Possibly both but whatever the sound has been mixed down to, there's no way to go back to a point further or closer to the source. So in some senses what layout before the master tape really doesn't matter because we cannot decode it.

And recordings are unreal by their process. Classical music is too closely miked compared to listening in a concert hall. The mike positions are too high, the closeness to the instruments mean that the mikes will miss some of the harmonic lobing that give instruments their characteristic voices. Also having the mikes so close means the room signature and reflections are not recorded. Imagine listening to a string quartet from above the players about 3 or 4 feet up. This sound can easily be over bright and hard. But if you place mikes and recorded at a concert hall distance, the sound will be thick and unfocussed. There will be no soundstage to speak of.

Of course rock and pop recordings are even further from realism in that multiple studios may have been involved, the tracks were laid down on different days using different mikes. Some performers never met during the sessions much less rehearsed together.

But at the same time, this is all we got and the tune unlocks many recordings for us.

Sonic is testing come control in the front and middle of the room. The room is coming under control but I just got to get the reverb of the room down a spot without shifting up in pitch or over damping.

Sonic

I know, kinda shoots holes in The Absolute Sound, but on the other hand soundstaging is so much fun and has it's own presentation to make. We just have to accept it for the art form that it is and let go of what some of the audiophile leaders have said and try to make it into. I wish there would have been other writers who could have given their thoughts to the recording soundstage process at the same time the "authorities" did to give some balance. Balance will come but for many too late as they have invested their money and time into following a ghost.

It may take a while but the art of having a recorded soundstage in stereo will come back around full circle and capture the imagination of the staging freaks. I for one am thrilled to be a soundstage child and enjoy it as my mainstream diet. The amount of music I get to enjoy because my stage is huge is unlimited.

Hi Michael and Zonees

While I respect Pearson and the Absolute Sound, I think HP's views on the wall to wall soundstage has conceptual difficulties. Even Abso!ute Sound writer Robert E Greene gently but clearly disagrees with what HP has pronounced on the soundstage...and from the reviews in the Abso!ute Sound, several reviewers appear to be listening rather loudly?

However Sonic is not out to comment on HP or anyone's idea of audio reality.

I improved the control of my room using this:



This tuning has redistributed the liveliness of my room better. Now I need to do a re-balance the room and system to get the musick to fill the room.

Sonic

I was wondering when the rug would come out.

Right now the carpet helps form a reduced and controlled reflection/reverb-reduced zone around the listening chair. Sonic understands that early reflections cause comb filtering effects which lead to uneven responses and listening fatigue.

Of course my system and all systems in one way or other are works in progress. So will the carpet be removed one day? Maybe, maybe not.

But not soon because I have stopped doing anything else to my system for a while.

Sometime this week, someone supplying services to my dwelling accidentally struck the main rack. The rack tilted badly, all the settings of rods centred and carefully set leveling were gone.

Now Sonic has knowledge of how to set up a rack from scratch and how to maintain a rack after it has been set up right then due to new equipment, or humidity slipped out of the best alignment. But I have no practical knowledge of how to bring a badly off balance rack back into set up without a major tear down and build up. So Sonic is learning how to rebalance a knocked rack and maintain stability.

The sound is noticeably affected for the worse. Sonic needs to get the rack upright and stable before I can make any more changes to the equipment, rack or room.

Sonic

Hi Zonees

Sonic thinks I got the rack balanced. Its been two days and the nuts don't tighten by themselves after being set correctly.

Hex-nuts of a Clamprack tightening by themselves can mean that the humidity in the room has gone over the top and the wood is expanding OR the rack is slowly tilting over due to instability.

Now that my rack is about stable (need to wait a bit to be sure), Sonic can get going on with the settling of the tune and the carpet. It is working now but let's see as I get the control of the BOO! improved.

Sonic

Thud rugs (my term) can do a lot of different flavors. I tend to collect tons of rugs in different materials and sizes. i find them not so much to be perminent but more mood changers. I'm currently using a woven backed bamboo one with fine strips. That is on the Ohio setup any way.

Hi Zonees

The rack is stable I think. It took some slow work and the hex bolts are where I left them after +72 hours.

Sonic

Takes a long time sometimes

Hi Michael and Zonees

The rack is stable. Which means I can (and must) relook at some of my recent tunes.

For now, a carpet is required in my room but whether it should be where I have it ahead of the listening chair or in another place in the room is to be worked out. I think we need to move the damping forward. And I should think of the height dimension.

Sonic

One of the main things to keep in mind when using a rug is the volume control. You can use this as a guide to balance. If you have to turn it up the rug may be in the wrong place. If you turn it down you are usually getting closer.

There's a tricky balance between stage fill in and volume that is sometimes a pain. On the quick fix I will let the volume go down but I know that down the road when I learn what I need to the volume will need to go back up and I will somehow need to find the same answers else where.

Now with the central rack stable again, Sonic finds that I need to revisit my recent tunes to see there is anything I did that was just to compensate for the ut of balance rack.

For one thing the carpet had o move here.



The volume has not changed much about the same before this tune.

Up next is my adventures tuning my AR XA turntable and bringing it down into the main system using a Pro-ject tube phono stage.

Next up -- Sonic had a good artisan help me with the he restorationg of my Acoustic Resarch own the AR- turntable. I might be getting here... Sonic.Beaver

Did I hear you say, you might be getting an AR

Sonic,

Yes, tell about your AR. I am almost ready to set up my Merrill TT with wooden headshells and older MI cartridges.

Greetings Zonees

You might have noticed my post last night ending in gibberish….here’s what happened: I was so tired after a busy week at work, I nodded off at my computer and hit send when I awoke a few minutes later.

Sonic usually composes the posts for each Friday a day or so before on MS Word, then copy the text over to the website. Not this week, no time. So I wrote last night’s stuff in directly but being not a natural writer, and tired too, I wrote stuff that I didn’t like and hit return to get the bits out of the way to the bottom of the page so I could recycle them later in case they make sense then . Doing this means I have to be careful to check the ends of my emails for garbage and erase them before sending.

Yesterday, this didn’t happen and the nonsense was off the bottom of the website panel where I couldn’t see it….

Yes, now about the AR XA as Garp asked.

Greetings Garp! I had an AR XA unused for years and in uncertain condition after buying it from a collector who was selling it off cheap. I tried using it but the arm was off, badly wobbling and I didn’t have the time or inclination to restore the machine. Sonic was also caught up by the convenience of CDs back then so the machine stayed in a cupboard.

I tried using it in one of the other systems in my dwelling but the first results were discouraging .

With my SP system, my interest in analog revived and I wondered if I should get a TT for 33s and 45s. Remembering there is the AR XA, Sonic decided to restore it properly and give it a fair go.

Now there are technicians in this town but most are not interested in doing painstaking work. They want to turn around gear fast and these have their hands full with all sorts of broken gear such as melted Krells after some high volume level encounters with Apogees.

About those Apogees, Sonic personally agrees with the view of a well-respected British speaker designer who remarked that if you ended up with a design that melted amplifiers then you are not a good engineer at all. Oops I digress….

Now the engineering behind the AR – particularly the three point suspension is excellent. I think Ed Villchur of AR got Mitch Cotter to do the design of the TT. It made audio history. Linn, Thorens and all suspended sub-chassis TTs trace their origins to the AR. The arm was however controversial. It had an odd damping device to prevent the stylus from hitting the top plate and breaking if the arm was accidentally dropped. The minimalist design had no cueing lever. Not the XA. The later XB did. The earlier arm (mine) had no anti-skate. The Manual just said if skating was a problem, increase the tracking force slightly by a ¼ gm…the later XB had anti-skate.

The first series of AR XAs had a starter motor and a second belt to get the platter moving. Mine is the later XA which has one motor with enough starting torque to get the platter turning.



Sonic finds the design beautiful. Err…you lift the platter and move the belt on the stepped pulley to change speed. So did the early Linn LP12s.

I know a great artisan in Singapore who would do the restoration work without cutting corners. Some repairmen I know have no respect for history and take appalling value destroying shortcuts. So Sonic made the arrangement and moved the AR down to his shop.

The good news is the walnut plinth is in amazingly good shape for a 40+ year old machine. The metal work decent (a bit of rust….but the platter shaft in good condition. The motor good, the belt loose but serviceable. The arm needed work, the horizontal bearing/shaft was rattling.

Let’s go.

Garp, I’ll be describing the restoration process but what aspect of this project would you like me to focus on to help you with the work you want to do on your Merrill?

Sonic

Hi Garp

Here are some things Sonic looked at in my AR XA restoration relevant to the similarities with the well-regarded Merrill ES-R.

The first thing Sonic did before any work like dismantling was to remove the bottom board which in the AR XA's case is a pressed wood/paper board with some slots cut in it.

A look around "under the bonnet" followed to see if there were any frayed wires, burnt wires, leaking capacitors, loose connections, major corrosion and such. It was fine in my case...

Next, I checked the Haydon motor -- I don't know what the Merrill uses. See if there is any vertical play in the shaft by lifting the pulley gently. Sonic understands that if you find any major up and down play of say 1/10 or 1/8 of an inch, the motor is kaput. I found no play in my motor.

Then without the platter and belt, start the TT. There should be no noise and also look at the pulley -- it should run without wobbling. Noise means some lubrication of the motor may be needed, wobbling means the shaft is bent or the pulley is distorted. The pulley can be trued but some say you can even bend the motor spindle to straighten it. Sonic has doubts. My AR XA ran true.

Next, put the belt on if it is not loose, place platter on. Start TT. It should have enough torque to get up to full speed on its own without help from you (or me). If not, the belt is possibly loose or the motor kaput. Usually it is the belt. Powder it and try again or get a new one from eBay.

Of course check if there is oil in the platter bearing well. For the AR XA, 10W mineral oil is recommended. 10 drops of Singer Sewing Machine Oil works nicely.

With bearing well oiled and the platter is spinning up to speed listen for noises. Any noise it could be a number of things like dry or worn bearings....mine was quiet. Touch your fingertips onto the top plate above the motor -- there should be no vibrations.

My TT got past these tests so Sonic and the artisan started the dis-assembly process.

Sonic

Sonic,

It looks like you on another journey. Many in the US are returning to the old ARs as well as the Merrills. I have been corresponding to one of the major restorers, David Archambault at the Vinyl Nirvana. He restores and sells ARs, Merrills, Thorens, and a few others. It has become a full time business for him as he sells several turntables per week from his website. He is also a good source for parts and suggestions.

If I can get some time in the next couple of weeks, I should have my Merrill ready.

Happy listening!

Hi Sonic

If you know of any where that has pics of these steps send them to me and I can post them.

Hi Michael and Garp

There are some very good “how to” sites on how to restore an AR XA. The one I followed as my roadmap is http://johnsweather.com/Turntable.html

Very clear photographs and well written. Sonic recommend it highly

Up to now, the turntable itself is coming along mighty nice....but the arm...Sonic thinks there is a problem ahead....

Sonic

Hi Garp and Zonees

The old AR XA arm with the damped vertical movement is much maligned by audiophiles. When new it undoubtedly worked or the turntable could not have garnered the reviews and sterling reputation it did.

The damping however needs adjustment and when the arm ages and the felt washer wears out, problems might occur. In Sonic's case, the arm condition was the only thing in less than "very good" condition in the TT. The plastic and felt washers on the horizontal pivot stem were missing so I made up new ones, but though the diameter was perfect, the thickness was a little too much.

So what's the problem?

The arm won't give consistent and repeatable tracking force.

Set to 2 gm using a Shure SFG-2 gauge, each lift/cue/lift cycle gave me a different tracking force reading. It could be higher or lower than the original setting to the point I don't know what the stylus force really is! It was more often too low.

So some test plays sounded excellent then the next record could have mistracking and ticks and pops that went off with Bang! as the too-light cartridge arm got thrown out of the groove....and on the few occasions it tracked properly Sonic was worrying it was wearing out the grooves.

For sure there is a solution. There is a tiny pin in the side of the roller bearing -- extract it and there is no longer any damping, then you locked the vertical shaft and bearing assembly and the arm is free.

Of course if that doesn't work there no turning back, and if it works the arm and turntable are no longer in original condition.

No choice, think Sonic needs to pull the pin.

If it works, the arm will free and the stylus force consistent. I can protect the stylus against an accidental drop with Magic Wood! Make a cradle from MW and all will be safe.

Sonic