Small Sweet Spot

[audioxcel]

I have Sequels (3rd set of panels) that I have owned since they were released way back when. I used to experiment with toe in to try to achieve better focus. Eventually, I decided to go with a precise straight front facing set up which I think gives the best soundstage and largest listening spot for more than just one person. I try for about 4 - 6 feet of good listening width with the best in the center.

I measure my speaker placement carefully and level in all axes as close as possible.

I don't use SPL meters or frequency sweep equipment any more when I make changes in my room. I just listen and move the stuff around in the room (furniture, pillows, lamps, etc) in small increments. I also will move the speakers sometimes during this process but usually just for final fine tuning.

It is tedious but at the end of the day, no matter what process you use it will come down to what "sounds best" not what you measure. I really could care less what graphs I can generate. If my system sounds great, is all that matters.

 

[Leporello]

Wow! Talk about a thread that's a "blast from the past!"

Including the snark about Obama. (Note: I don't discuss politics here or on any other audio forum. If you want to debate politics there are about a million forums to do that on).

The first thing to understand about "sweet spots" is that soundstage is an illusion. A stereo system consists of two discreet sound sources, end of story. But because of the way the human ear localizes objects in space, we get an illusion of performers occupying a space. How convincing that illusion is depends on a number of things. Bottom line, I don't think there are any measurements that would be very useful. Martin Logan has always recommended as a starting point toeing in the speakers mid way between aimed straight out and directly toward the listener, such that you're effectively listening to the outer third of the panel. I have found that useful as a starting point. But in any particular room and setup, you're just going to have to experiment to get optimum results.

In my living room, the sweet spot is at one end of the sofa. I can move to the other end and still get an illusion of different sound sources but, of course, they're bunched up toward one side. I've never heard any speakers where this wasn't the case, no matter how placed or toed in. But the ML's being more directional than most, the optimal "sweet spot" is relatively narrow--though hardly "head in a vice". I don't find this at all limiting. My companion only occasionally joins me for music, much more often for TV or movies, and either way is not a fanatical audiophile who cares at all about sweet spots (I tell her my sweet spot is next to her). I once used Acoustat 1+1's and even made those work for me, though the sweet spot is considerably narrower.

I don't know where the poster from the past got the idea the curved panels are worse. They're brilliant, and wider sweet spot is the whole point of them (though the focal point on the wall behind them could be problematic if they were too close, or the wall too reflective). At some point Sanders must have determined 30 degrees was the optimum nominal dispersion, and designed for that. The still rather narrow dispersion, though, helps minimize interactions with the room--relatively little reflection off the floor, ceiling or side walls--and along with the quick transient response contributes to the immediacy of the sound that we all (most of us) love.

 

[Jazzman53]

I used to have DIY flat panel ESL's which beamed like crazy and the sweet spot about 1ft wide. This was great for solo listening at the focal point, but useless for someone sitting right beside.

I found that the best compromise to get a two seat-width sweet spot was aiming the left speaker at the right seat and the right speaker at the left seat. This cross-aiming thing was not ideal but better for two people listening than having both speakers aimed at one seat.

If it helped with flat panels it may work better with curved panels. I've never owned a ML curved panel so I can't say either way.

My current homebuilt ESLs use symmetrically segmented wire stators which drive the diaphragm sequentially from the panel centerline to the panel edges. The segmentation drive-scheme projects a wider, smoother-trending dispersion pattern than a 30-degree curved panel or even most conventional speakers. The pattern width can even be tailored by tweaking the drive network resistor values.

But there's no free lunch: Widening the dispersion takes away some of the magical imaging you get at the focus of a narrow dispersion ESL

Give the cross aiming trick a try-- it might work for you.

 

[Kgveteran]

I look at frequency response for signs of comb filtering, but also listen to multiple tracks for imaging and width of sweet spot.

Last night during a good 2hr listening session i moved them back against the front wall and opened up the width too, i listened for awhile, im curious if i will like them tonight haha

 

[Duke]

When you get to razor imaging but want it wider, put on a narrow beam capable headlamp instead of a flashlight. Repeat what you did with the flashlight. Your speaker is not very wide and the more pinpoint you can make your beam the better. View the reflection of the light from the center of your forehead onto your panel in a dimmed but not dark room. I read that in a post years ago on this site. If your beam hits a bit to the inside of the closest point of the Martin Logan cls type panel, (the apogee of the curve), then your image usually gets a bit bigger as the center of the panel is directed a bit outside of your ears. Having the headlamp in an appropriately lit listening space really helps you configure the image and assures that your toe in is symmetrical on both speakers. Sitting and carefully pivoting your head to each speaker was the quickest way I ever tried to handle the image. Have a friend visit to move things around once you get really close to what you desire. Tape up your floor.
Measuring the edges of your speaker to the back wall really helps augment what your headlamp can do (which is the toe in) by providing the distance from wall. Repeat these two and tighten up the music to give you the result you find most pleasing.
You are right to have a larger room to play your Odysseys and set them further into the room. I did that when I read it was a good idea on this site. I listen to my clsiiz speakers at ~9' from the speaker to my seat. I endeavor to make the setup more like nearfield listening at the recording studio or computer to avoid nodes at my ears. Even though we both have a large enough room, I like the concept of nearfield listening but on a larger scale which is why I like the back wall as far away from me as possible so I don't have to deal with it. I do not know if 9' is any different than your 11' but it works at 9' if you need more space behind your ears. The music goes past my ears a long way before it hits the back wall. (~25'+). I would research if a 12' length is problematic with room nodes.
Your Odysseys are thinner across than my panels. They may need a lot more incremental positioning to widen your sweet spot the way you describe. For the sake of your floor I would avoid using spikes until you get them positioned to that state. It also saves a lot of time in the long run. Use blue, green, or yellow tape a lot to mark speaker positions.

I like the Oyaide R1 outlets and anything with rhodium plating. Electric conditioning is where I read somewhere you should start as a tweak with electrostats and you have done that. I like aftermarket fuses because they are in the power. I feel that with adequate power conditioning, you will be able to hear what different cables can do. I envy those who have a bigger budget and I have to think that a lot of these enthusiasts can get value for the larger dollar purchases. Maybe some are just spending. One thing I often see is that they all mention some type of power conditioning and then the cables. I think the power conditioning is cheaper than expensive cables and a good place to start. I feel from experience that you need both for cables to make a difference.
For me, electricity is like the water I drink. I don't drink tap water anymore. I use a RO filter.

I am sure there are many ways to get your problem solved. This is how I approached getting a two seat sweet spot for myself. My vocalists are quite large and open sounding. Some people do not like a four or five foot wide mouth but I sure do. It is to die for. I use a sofa. You use chairs.

 

[GWS2000]

May I add?

The whole thing behind ML creating the curved panel was to widen the enjoyment of the listening area. My Classic 9's are 13' center to center apart, panel is 3.5' from the front wall and my 3 'passenger' sofa is 20' back.

I used Martin Logan's flashlight method for toeing. I tried everything to deviate from that position in all possible ways. It seems that the benchmark, at least in my 18x24' space works best.

Stereo spread is enjoyed by 3 listeners at the seating position.

One last comment. Keep in mind, 'stereo sound stage' and 'stereo image' are two different things. That is all.

 

[sleepysurf]

Here's my technique for adjusting speaker positioning. I carefully place two parallel pieces of adhesive ruler tape (Amazon link) on floor for each speaker. I then use a large level (2 x 4 sized) that's tall enough to place firmly against the front rails, and experiment with fore/aft speaker position and toe-in. I jot down the position, then listen carefully, making ~1-2" incremental moves to start, then narrow it down further with 1/2" then 1/4" changes. I focus mainly on soundstage width, depth, and overall tonality, with less focus on deepest bass (as I "tune" that later with ARC, plus separate sub).

This is my current configuration, and flashlight reflection shows more extreme toe-in than most recommend.

With my room, and acoustics, I have an excellent (if not perfect) sweet spot that is ~2 people wide, and still provides good imaging and tonality for all other sitting positions (even those far off-axis).

This post of mine explains how I use an inexpensive angle locator to adjust rake angle... How does rake adjustment affect sonics?

Of note, I use Summit X modular leg assemblies on my Expressions (purchased separately from ML years ago), which allow easy and exact rake angle adjustments. see this post... Summit X legs compatible with Renaissance, Expression, and Impression!

I just switched from a 5° to 3° angle this past week, which improved clarity and dynamics a bit with the current configuration.

 

[GWS2000]

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[GWS2000]

Here's my technique for adjusting speaker positioning. I carefully place two parallel pieces of adhesive ruler tape (Amazon link) on floor for each speaker. I then use a large level (2 x 4 sized) that's tall enough to place firmly against the front rails, and experiment with fore/aft speaker position and toe-in. I jot down the position, then listen carefully, making ~1-2" incremental moves to start, then narrow it down further with 1/2" then 1/4" changes. I focus mainly on soundstage width, depth, and overall tonality, with less focus on deepest bass (as I "tune" that later with ARC, plus separate sub).

This is my current configuration, and flashlight reflection shows more extreme toe-in than most recommend.

View attachment 23759

With my room, and acoustics, I have an excellent (if not perfect) sweet spot that is ~2 people wide, and still provides good imaging and tonality for all other sitting positions (even those far off-axis).

This post of mine explains how I use an inexpensive angle locator to adjust rake angle... How does rake adjustment affect sonics?

Of note, I use Summit X modular leg assemblies on my Expressions (purchased separately from ML years ago), which allow easy and exact rake angle adjustments. see this post... Summit X legs compatible with Renaissance, Expression, and Impression!

I just switched from a 5° to 3° angle this past week, which improved clarity and dynamics a bit with the current configuration.

Wow, lots of detailing into toe in angles.

I run my Classic 9's straight out. They are just over 13' apart and my 3 cushion sofa is 20 ' from them. Wide image is enjoyed by all in the seating area. Toe in ends up creating a single listening 'station'. Not good when you want to share a wide sound stage with others. Just experiences in my dedicated space of 18x24' with room treatments and pretty much empty of un-important 'stuff' as found in standard living spaces (O