Placement tips for Synergistic Research HTFs

Excellent write up of results with the transducers and resonators. As I predicted trial and error is not really an effective way to obtain maximum results with resonators or transducers. And even following general diagrams can be risky. The only methodology that avoids all the pitfalls described in Toolbox’s post is the one is suggested early on - using a SPL meter and test tone to establish where exactly the sound pressure PEAKS are in the room. The best you can possibly do with a trial and error methodology is what is usually called a local maximum. It’s a lot like trying to find the absolute best speaker locations by trail and error. Only worse, since there are many more things to find locations for. Make sense?

The technique of Trail and Error is like trying to solve say 10 simultaneous equations in 15 unknowns. This problem with resonators is exactly the same problem at audio shows where there are a number of empty beer or coke bottles lying around on tables and on the floor. They act as resonators and affect the sound, mostly negatively, moving the soundstage around in weird ways and changing tonality and frequency response. Once you misplace one resonator or more, it will be more difficult to get good results even when proper locations are found as you proceed. Make sense?

With the SPL meter technique you can cut your time down tremendously and you will obtain much better results. Think of soundstage as a 3D sphere, what you really want to achieve is a centered deep and wide and high soundstage, one that is transparent and full of details and life. As the soundstage becomes more fleshed out and centered you should observe the 3D sphere expand like a balloon being filled up. CORRECT placement of transducers and resonators will results in smoother and more extended frequency response, without the peakiness some have noted. 

Thanks for the great write up, toolbox. Today I took all the DIY resonator cups off the walls and speakers. I'll probably throw them away. But I did have a ton of fun making them and playing with them for the past couple of weeks. I thought these things deepened the sound stage... but I was wrong. I was simply trying to defend my investment ($30 and labor and expectations). Just a placebo effect.

Well, I went from a gazillion resonators down to just ten.  With the smaller amount,  I do hear a nice addition to, and a repositioning of my soundstage.  Not the groundbreaking, earthshaking change some have stated, but a nice little tweak, nonetheless.  I'm happy!
My most pleasurable gain came by adding a resonator to each side of my front speakers. The outside resonators provided me with a slightly wider stage but also more ambiance. The inward facing resonators brought the singers and main instraments closer in toward center stage while providing much more definition for the individual parts.  This was done with just four resonators.  I got a little greedy and doubled the resonators (now with four facing inward and four facing out) with the new resonators placed about 15-18" below the first resonators.  The result was more muddy and harsh.
So now, I'm a confirmed minimalist when it comes to using these things.
Hopefully, you don't throw your resonators away.  Maybe after some time with no resonators, you might try adding one to the inside of both your speakers or maybe try the outside edge.  For me, I found that having my inward facing resonators at ear level (when seated) and my outward facing ones about 1 - 1.5 feet higher gave me the best reward.  That's as high off the floor as I would ever want to go.
But in the end, it's all about what makes the best music to you and your ears only.  So, if you end up liking music better without them - leave em' in a box.
BTW I have a couple of different versions of your resonators and they work very well for me.  I just built a few more smaller resonator types so I could test if different cone sizes affect different frequencies.  I also used heavier and lighter bases for the resonators to find out if the base material affects the sound.  Hopefully, I'll have the time to do the testing a couple of times, and write up a report soon.  I'm gonna try get it out this weekend or maybe early next week.  
Thanks for all your help.

Toolbox

Jkbtn - yeah, it’s a very subtle effect, much less noticeable than cable changes. If I had paid serious money for these, I’d be not very happy, or telling myself they work better than they do. Though maybe the official ones work better. Though I’m sceptical. Very sceptical.

I agree they are fun to make, and I’m content with their performance relative to my time and money outlay.

Toolbox - I'm interested to hear your results with the different sizes/weights.. thanks again.

Just as I predicted and thanks again for the detailed report, Toolbox. More is not more sometimes. Lol

The problem with going off a little bit half cocked as it were with these transducers and resonators is that it very easy to do more harm than good. And without knowing what to look for in terms of results one is tempted to jump to certain conclusions too quickly. Once you have committed to a bunch of placements that are not "good" it’s very difficult to correct for these mistakes down the road, I.e., by adding more and more. The damage has already been done. It’s what we call going too far. Icarus ignored his father's warnings and went too far too fast and fell to his death. 😥

Are the real and more expensive transducers and resonators more effective than these DIY jobbers? Has anyone here read the reviews of the real McCoys, you know, the Franck Tchang resonators made of pure platinum or silver or gold, the ones DIYers abhor? 😧 Or the real SR transducers? It’s a lot like trying to knock off Shun Mook Mpingo discs without understanding the principles involved. Or trying to make bread without the benefit of a recipe.