Ron’s New System

[Ron Resnick]

Hello Ron, are the speakers on spikes or some adjustable foot? If so have you leveled the speaker to a high degree of accuracy? (0.01 degrees) I find that small chamges in speaker azimuth make very audible changes in the 1-5 kHz range.

Thank you for the suggestion

There is no adjustment mechanism on the feet. But with a 6 foot tall, nearly full range, line source driver I would be surprised if a small tilt forward or backward had much effect on the tonal balance.

Whether sitting down or standing up the tonal balance stays pretty constant, according to Steve Lefkowicz who visited yesterday.

 

[Mike Lavigne]

Thank you for the suggestion

There is no adjustment mechanism on the feet. But with a 6 foot tall, nearly full range, line source driver I would be surprised if a small tilt forward or backward had much effect on the tonal balance.

Whether sitting down or standing up the tonal balance stays pretty constant, according to Steve Lefkowicz who visited yesterday.

i would be surprised if you did not get considerable musical focus gains from laser leveling, orienting and locating. my friend Andrew helped me with that some years ago with my MM7 towers and the results were quite startling. tiny changes mattered. he had lasers for the tops of my speakers and that attached to my tweeters with magnets. first you do need a grid on the floor to find the center line.

there is a period of making gross changes where it's not practical, but the laser alignment process needs to be part of the plan.

and you are wrong, wrong, on your assumptions about a line array, if it's not aligned and level it will be much worse than a conventional design, analogous to a linear tracker that is worse than a pivot when it's not aligned since it's always wrong. more musical smear. but better when it is.

precise cohesion matters big time. the taller the speakers, the greater number/size of the drivers, the more it matters.

 

[Johan K]

I agree with Mike. When I had placed my Martin Logan ReQuest speakers roughly at the right place, I did hundreds and over hundreds of micro adjustments to the ReQuests to get the sound I wanted. They are a 100% vertikal in all directions with a slightly toe-in to get the right horizontal dispersion which I favour. I have tried to tilt them back and forward, but zero tilt (100% vertical) works best here.

At the same time I did almost as many micro adjustments to the listening position - front and backwards to match it up with the ReQuests… It sounds like that is done in a jiffy.. but it is not - I tell you… It took me over three years of tiny adjustments to get satisfied. After that I have never ever moved them.. I have not need to.

I have found that all measurements are critical. The distans to everything in the audioroom matters, and can not be solved in a few weeks time - not even by the wisest - it takes time and hard work to get it perfect.

Also at the same time I have worked with the room acoustics and acoustical treatments for different frequencies. I use both absorbering and diffusing treatments in various places of the room to get it alive, and not overdamped, nor too lively… That is why I never get tired in my ears even after a 12 hour session of listening.

/ Jk

 

[KeithR]

i would be surprised if you did not get considerable musical focus gains from laser leveling, orienting and locating. my friend Andrew helped me with that some years ago with my MM7 towers and the results were quite startling. tiny changes mattered. he had lasers for the tops of my speakers and that attached to my tweeters with magnets. first you do need a grid on the floor to find the center line.

there is a period of making gross changes where it's not practical, but the laser alignment process needs to be part of the plan.

and you are wrong, wrong, on your assumptions about a line array, if it's not aligned and level it will be much worse than a conventional design, analogous to a linear tracker that is worse than a pivot when it's not aligned since it's always wrong. more musical smear. but better when it is.

precise cohesion matters big time. the taller the speakers, the greater number/size of the drivers, the more it matters.

Mike, what was your method for finding the best positioning of the MM7s in your room?

 

[Gregadd]

Mike, what was your method for finding the best positioning of the MM7s in your room?

now that's a journey. i wonder if I have any microwave popcorn.

 

[cjfrbw]

Pendragon has that nifty feature that allows separate equalizations for sub 100 and 100 to 300 range with Q control, and a 'passive' tweeter that also has some adjustment, giving a kind of four way adjustment scheme, very handy.

I have the 75 inch ribbons toed in slightly, which is perfectly satisfactory in my equilateral triangle type listening, but I haven't tried them any other way.

 

[Mike Lavigne]

Mike, what was your method for finding the best positioning of the MM7s in your room?

Keith,

my large room being 29' x 21' and the front 1/3rd hardwood flooring, i had always expected the speakers to be forward quite a ways. i wanted the sense of space lots of room behind the speaker could allow.

part of having the speakers into the room, is the very wide 21 feet, and built in diffusion, so the sidewalls and early reflections, are not so prominent to the presentation.

Started with the rule of thirds with my Kharma's, in 2004, then the VR9SE's in 2005, and the MM3's in 2006. moving each of these around i did find a preference for the front baffle to be about 9 feet in, and 9-10 feet tweeter to tweeter. at that point i was sitting in the far field. not close up like now. i did have a 'U' shaped sound stage for a number of years until much later when i did my final room tuning. deep but not as wide as it should have been. that was connected to using an RPG diffuser stack on the front diffuser baffle. but always a great sense of space and scale.

then with the twin tower MM7's in 2012, and wanting a cohesive wave launch, i ended up 9' 6" in to the room, and 110 inches tweeter to tweeter, to allow for the bass towers along side. i liked that. and by this time i was sitting closer, at the top of the equilateral triangle as the room and system maturing allowed for closer listening.

18 months later when Kevin Malmgren visited we did move the main towers slightly closer together. 108" tweeter to tweeter. about 9 months later i started my final room tuning process, never moved the speakers except re-aimed my main towers at my closer listening position as i moved into the near field. and all my final room tuning efforts did spread the sound stage across the whole room with no holes and on most recordings the speakers and room disappears.

 

[emoonie]

Hi Ron. Amazing journey, thanks for sharing. Regarding toe in with planars my experience is opposite (sort of) with others leading me to believe there are no set rules.
My first planars were Acoustat Monitor Fours. I preferred them toed in for image placement focus but that exacerbated the head in vise effect.
Next the Apogee Divas insisted on zero toe in and perfectly level (side to side, front to back) to sound their best for me.
The third planars I owned were Genesis 350s which I didn't toe in but that probably had more to do with keeping the bass drivers away from the corners and ribbons apart in my too small room. Never did get the bass right with those.
And finally my Gilmore Audio Model 2s whose second generation ribbon 160 to 35khz was built by BG to Gilmore Audio specifications after Mark Gilmore was able to get them to agree to a non disclosure agreement. Anyways Mark recommends toe in and canting them back a bit which the Sound Anchors stands accommodate. Of course I tried otherwise but in this case designer knows best.
In the end each time small fractions of an inch movements were audible.

 

[Ron Resnick]

Pendragon has that nifty feature that allows separate equalizations for sub 100

I do not know what you're talking about here.

 

[Ron Resnick]

'passive' tweeter that also has some adjustment,

There is only a -1dB, flat, +1 dB adjustment on the air motion tweeters which start at 18 kHz.

 

[Mike Lavigne]

Mike, what was your method for finding the best positioning of the MM7s in your room?

one other point. Kevin Malmgren commented that due to the huge diffuse space behind the speakers, that the speakers were effectively farther back in the room acoustically than 9'6" off the rear wall to the baffle. which was why my near field listening works so well. all those drivers, and two towers, are seemingly perfectly coherent and balanced.

i can't explain that acoustically, but that is what he said.

 

[sbnx]

Thank you for the suggestion

There is no adjustment mechanism on the feet. But with a 6 foot tall, nearly full range, line source driver I would be surprised if a small tilt forward or backward had much effect on the tonal balance.

Whether sitting down or standing up the tonal balance stays pretty constant, according to Steve Lefkowicz who visited yesterday.

If you don't have adjustable spikes or feet then it is a moot point but I am not really talking about spectral balance. Sitting down and standing up is way to coarse of a movement. Tilting forward and backward is the rake angle. This can matter also and in your case would probably be most significant if say the right speaker were raked back a few tenths of a degree and the left speaker was raked forward a few tenths of a degree. This offset causes high frequency 'hash'.

I would like to explain the effect like this. Have ever heard two instruments (e.g. trumpets) playing at the same note at the same time and one is slightly out of tune with the other. The sound will not be a pure tone but will have a clear "Wa-wa-wa" to the sound. If the drivers are offset then this same thing happens and it sounds like irritating high freqency hash.

The "tilt" i was referring to is the azimuth (left to right tilt). The azimuth has a great amount of control on coherence of the sound and how we (I) percieve high frequencies. (Anything above 1 kHz.) Very small (0.01 or less of a dregree is clearly audible) The way I would think about this with regards a stack of planar-magnetric drivers is if the speaker is tilted to the side then the drivers are obviously not stacked perfectly vertical relative to one another. Each driver has a dispersion pattern that is frequency dependent. if they are stacked exatly vertical then those waves overlap perfectly with each other. if they are not vertical then there is going to be an interferrence pattern. Then we are back to that high frequency hash thing.

I have attached a picture that researchers were able to take (using lasers) to show the pattern of sound waves being emitted by a speaker at different frequencies. I hope this help you visualize what I am saying.

I am not sure if the above stuff helps you. In summary, I would try to do everything in my power to get the speakers perfectly level.

 

[msimanyi]

@sbnx When you say perfectly level, do you mean relative to plumb, relative to the front wall (the wall behind the speakers,) or some other reference?

 

[sbnx]

I personally use a NIST certified digital level that is accurate to 3 decimal places. So perfectly level to me means 0.000 degrees in X and Y.

However, this is just the starting point. After that I adjust by ear and use the level simply to keep track of adjustments so I can go back if needed. For example, my new speakers only have 3 spikes. So when I adjust rake then is messes up the azimuth. I can use the level to get the azimuth back to where I started before the rake adjustment.

I am actually making some videos of the process as I setup the new speakers. I will post them here on WBF at some point.

But for Ron, there are some pretty cheap ($20 - $50 range) digital level cubes that show 2 decimal places but are really only good to about 1.5 decimal places. You can set it on the floor and zero it out then put it on the base of the speaker to at least get some idea. Check you favorite big box online retailer and you will find a good variety.

 

[Ron Resnick]

Thank you for this background information. But if you are trying to achieve, and you want me to try to achieve, this level of precision, we are having to assume that the ribbon driver suspended within the metal structure of the panel is perfectly parallel to the outside of the metal structure, no?

In other words trying to achieve this level of precision we are only measuring the rake or vertical-ness of the structure, but don't we really want to be measuring the rake or vertical-ness of the actual ribbon driver inside the structure? If we are measuring the speaker cabinet we are having to assume the ribbon driver is perfectly positioned in all dimensions inside the cabinet, no? Isn't measuring the cabinet really just a proxy for the ribbon driver suspended inside?

 

[Gregadd]

i am sure the speaker is square. it does depend on degree of measurement. you can put a level to assure it's plum. just put a marble on it. if it's plum the marble should remain stationary.

 

[sbnx]

Thank you for this background information. But if you are trying to achieve, and you want me to try to achieve, this level of precision, we are having to assume that the ribbon driver suspended within the metal structure of the panel is perfectly parallel to the outside of the metal structure, no?

In other words trying to achieve this level of precision we are only measuring the rake or vertical-ness of the structure, but don't we really want to be measuring the rake or vertical-ness of the actual ribbon driver inside the structure? If we are measuring the speaker cabinet we are having to assume the ribbon driver is perfectly positioned in all dimensions inside the cabinet, no? Isn't measuring the cabinet really just a proxy for the ribbon driver suspended inside?

Ron, you are right in that the speaker (no speaker in fact) is not manufactured perfectly. However, machine tolerances are generally pretty tight and Gryphon is a company obsessed. So in a perfect world the drivers would be perfectly perpendicular to the base in both rake and azimuth. In there real world there will be some variation. But by getting the speaker (base) as level as you can you are starting somewhere. From there is can be adjusted by ear. But first we should assess how out of level they are.

One Idea that you can use is to get one of the laser levels that shoots both a horizontal and vertical line. These are self-leveling. So once you put it on a tripod you can line up the vertical laser line with the outside (or inside) edge of the planar-magnetic drivers at the bottom and see how much the top one has drifted off the line. This will be a very accurate process because the speaker is so tall.

 

[Ron Resnick]

The only way to change the rake of the speakers would be to slip spacers under the front feet or under the rear feet.

 

[sbnx]

That's ok. I started this discussion with the thought of sharing the idea that this type of thing can cause brightness and fatigue. And I think it is very often overlooked.

You could measure the "levelness" of the speaker and then decide if it is something worth pursuing. Where there is a will there is a way.

 

[Ron Resnick]

That definitely is not a source of brightness I would have thought of. Thank you for suggesting it!