For the past 9 months I have been on a tear making changes all over my system and fortunately producing benefits that have put a huge smile on my face and an equally huge dent in my bank account. As I come to the end of the line to this protracted session of audio tweaking I would like to share one of the most dramatic changes that I have made in a long time, and it was free, and in retrospect obvious.
This simple change that should have been obvious, but wasn't to me despite more than 30 years of mating various subwoofers with various speakers that I was rolling off naturally, has to do with changing the crossover frequency of my twin JL 113 subwoofers and the need for minor phase control adjustments to try to match them optimally to Martin Logan Montis speakers. My ML's are supposed to roll off naturally around 29Hz (like a Summit X with only one front firing woofer and no down firing woofer to muddy things up), but I was recommended to set the crossover frequency to my JL around 38-40 hz, which is where they have been set for almost a year producing what I thought was quite impressive bass. As a somewhat seasoned listener and one who has listened incredibly critically during all of my changes during the past 9 months, including more than $50k of Shunyata and MIT cables, PC's and power distribution products, the addition a Spectral 260 amp, a Meitner DAC and new CD transports, I have become very attuned to subtle changes in bass attack, phase, harmony, etc.
So after I got done with the latest changes (new dedicated 20A power circuits for the amp, subs, and the front end components all with a dedicated 8' ground pole separate from the rest of the house, Shunyata outlets, retubing my BAT preamp) it was time to sit down and see what all of the time, effort and money produced at the hopefully final stage of tweaking. It is important for you to know that my JL's are in the same planes as the ML's, so it is very easy to obtain cohesion with the ML powered sub and electrostatic panel that is not possible if they are set back as is usually the case.
While my sound was great, the bass amongst the best I have heard at any price, something was wrong around 30-45 Hz, mostly a tiny bit of muddiness that was not present at any other frequency. Then the obvious hit me, try dropping the crossover point on the JL's so that there would be less overlap in the area where I was hearing muddiness. I dropped the crossover point from 38 to 32 Hz and the bass instantly became substantially tighter, but a bit short on the output, so I raised the woofer volume at most a db. Now the bass was the best I had ever had with regard to cohesiveness of the bass coming from the JL's, the ML powered woofer and the ML screens. The leading edge and attack were excellent, but something told me there was more improvement to be had.
I am pretty good at setting phase between subs and speakers and thought that what sounded best to me with too much overlap between subs and speakers might not be the best setting with the lowered crossover point and less frequency overlap. A mere 5 degree reduction in phase produced such a dramatic change in sound, instantly obvious, even way off axis, that I could have never predicted, although in retrospect is what physics would dictate. The phase shift not only cleaned up the mating of JL and ML bass as predicted, it also cleaned up the ML screens top to bottom to a magnitude that I would have been pleased to achieve after spending $5k on a some component. The screens were more articulate, smoother and most important, more realistic than I had ever heard them sound. Perhaps most interesting, the typical sound that I have associated with all ML's, especially the 4 pairs that I have owned over the years, was undetectable.
So as I hopefully make my last post of the many I have made during the past 9 months of my most recent tweaking phase, I am reminded that what makes the sound of my system so engaging is not primarily the components, but how they are set up and the attention to subtle details, especially the obvious ones that are clearly delineated by physics.
This simple change that should have been obvious, but wasn't to me despite more than 30 years of mating various subwoofers with various speakers that I was rolling off naturally, has to do with changing the crossover frequency of my twin JL 113 subwoofers and the need for minor phase control adjustments to try to match them optimally to Martin Logan Montis speakers. My ML's are supposed to roll off naturally around 29Hz (like a Summit X with only one front firing woofer and no down firing woofer to muddy things up), but I was recommended to set the crossover frequency to my JL around 38-40 hz, which is where they have been set for almost a year producing what I thought was quite impressive bass. As a somewhat seasoned listener and one who has listened incredibly critically during all of my changes during the past 9 months, including more than $50k of Shunyata and MIT cables, PC's and power distribution products, the addition a Spectral 260 amp, a Meitner DAC and new CD transports, I have become very attuned to subtle changes in bass attack, phase, harmony, etc.
So after I got done with the latest changes (new dedicated 20A power circuits for the amp, subs, and the front end components all with a dedicated 8' ground pole separate from the rest of the house, Shunyata outlets, retubing my BAT preamp) it was time to sit down and see what all of the time, effort and money produced at the hopefully final stage of tweaking. It is important for you to know that my JL's are in the same planes as the ML's, so it is very easy to obtain cohesion with the ML powered sub and electrostatic panel that is not possible if they are set back as is usually the case.
While my sound was great, the bass amongst the best I have heard at any price, something was wrong around 30-45 Hz, mostly a tiny bit of muddiness that was not present at any other frequency. Then the obvious hit me, try dropping the crossover point on the JL's so that there would be less overlap in the area where I was hearing muddiness. I dropped the crossover point from 38 to 32 Hz and the bass instantly became substantially tighter, but a bit short on the output, so I raised the woofer volume at most a db. Now the bass was the best I had ever had with regard to cohesiveness of the bass coming from the JL's, the ML powered woofer and the ML screens. The leading edge and attack were excellent, but something told me there was more improvement to be had.
I am pretty good at setting phase between subs and speakers and thought that what sounded best to me with too much overlap between subs and speakers might not be the best setting with the lowered crossover point and less frequency overlap. A mere 5 degree reduction in phase produced such a dramatic change in sound, instantly obvious, even way off axis, that I could have never predicted, although in retrospect is what physics would dictate. The phase shift not only cleaned up the mating of JL and ML bass as predicted, it also cleaned up the ML screens top to bottom to a magnitude that I would have been pleased to achieve after spending $5k on a some component. The screens were more articulate, smoother and most important, more realistic than I had ever heard them sound. Perhaps most interesting, the typical sound that I have associated with all ML's, especially the 4 pairs that I have owned over the years, was undetectable.
So as I hopefully make my last post of the many I have made during the past 9 months of my most recent tweaking phase, I am reminded that what makes the sound of my system so engaging is not primarily the components, but how they are set up and the attention to subtle details, especially the obvious ones that are clearly delineated by physics.
