Following more measurements, moving from a high back sofa recliner to a West Elm Enzo mid back recliner with a folding headrest is next to remove the mid-range peaks developing around the ears.
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Good thinking…
Our new, powered recliner sectional was purposely selected (in part) because the back was high enough to be comfortable for long-term sitting/movie watching and low enough to not be behind my neurotic, audiophile ears when I settle in for some “serious listening”.
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I think you should give Milt Jackson’s vibraphone a whirl, perhaps Ballads & Blues. That’ll test it.
I suppose the advantage of such an amplifier is that if your house disappears Wizard of Oz style in a tornado, not that I would wish that on anyone, you will always have a marker for where it once stood.
The disadvantage is that you need two power cables. I reckon that’s added another $30 that you hadn’t planned for, besides the cost of a good osteopath.
Did you consider a pair of Plinius A-300 monoblocks? Then things would have really rocked. Only 250lbs and draw 1,400w each when operating in Class A.
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Yes, I vote Plinius as well 
I’ve been following these measurements of the various configurations you’ve tried with some interest vee. However, the scientist and engineer in me says be cautious with interpretation without knowing the uncertainties in the measurements. There are fluctuations between #1 and #22 that are at most 4 dB and over most of the range you measured much smaller. Were I doing this I would not ascribe any differences as real without ascertaining the uncertainty in what you’re measuring. What is the fundamental calibration accuracy of the microphone you’re using? Suppose you run any one of these scenarios repeatedly and compute the standard deviation of those repeats? What is statistically real? I’m genuinely curious because I’ve been thinking about these measurements you put a lot of (very admirable effort) into might mean for me. I’m almost tempted to try something like this myself, but would be interested in your thoughts about uncertainty in the experiments you’re making for informed decisions.
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I have a friend who had an SB-301. It blew up (he shorted it) and replaced it, but it sat in a corner until he had the house rebuilt. Let the builders deal with it.
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I use a UMIK-1 mic that has a calibration file. One problem I found early was somehow the MacOS MIDI volume for the mic was increased that caused SPL readings to read 10dB higher than my Reed. I have my Mac/REW outputting to the DSD via USB. A mic stand is a requirement.
My process is as follows:
- Start from where speaker position, toe in, cabling, tubes sound good and ensure mic is in exactly same position and orientation.
Then, iteratively:
- Measure five times: LR x3, L, R
- Review SPL, phase, group delay, impulse response, reverb time decay, waterfall and spectrogram in 1/24 and psychoacoustic smoothing
- Observe peaks, dips, resonances. Use the Overlays function to compare visually, toggling between smoothing to see nuances. If the observations look improved, swap inputs to the Sound Check playlist and listen. If it sounds better, move to the next issue. If no change or worst, abandon.
- Create a hypothesis on changes to make to affect variances, make the change and go back to 1. I will only change one variable at a time. Throughout, I’m recording the static attributes before making a new change.
Some things I’ve learned:
- There’s comb filtering, which I attribute to what you observe as -/+ 5dB variance in the mid-highs. I mostly ignore this because it’s incurable and less an issue when you consider the left and right ears are separated by 5-6inch at MLP whereas a mic is a single point.
- I’ve been looking at the FR down slope from mid to high. I finally determined the cause after doing some near field measurements @Vmax suggested (thanks!). It showed a flat response in the mid region from 3ft away. That meant something in the room was causing the slope down, and following more iterations, I learned it was my high back sofa absorbing and reflecting some frequencies.
- I found flattening certain areas of the curve do not necessarily sound better to my ears, and I abandon those changes. For example, I actually prefer a slight reduction in the 1k-4k range, which pushes vocals back slightly in the sound stage. To do this, I move the speakers apart, so there’s less coupling.
- Fractions of inches matter to the graph, whether it’s speaker separation, toe in, mic position so I take that into account when I see a big deviation and remeasure.
- Cabling and tube measurement changes are visible in the FR, GD and spectrograms holding all other variables constant.
- FR changes are not easily discernable nor obvious for characteristics like air, space, and micro details. I use my ears and live recordings with natural sounds for those. Some here use vocals, which is good, but doesn’t seem to cover things like floor/pedal creaks, fingerplay sounds, leading string pluck details or string bow flutter sounds. A finely detailed leading impulse is often missing in less resolving systems.
- The HF response on the Stenheims seem to converge best when toed away from MLP, so they’re not facing me square on. When I tried that, the soundstage was concentrated mostly between the speakers. The larger Ulfberhts did not behave this way and preferred to be more square facing me.
- I added a lot of bass trapping for the Ulfberhts, which had woofers 7ft in the air. I’ve since removed all rear wall and side wall trapping. The corners and ceiling vault traps are still in place, though I plan to remove some corner traps to see if the low end 60hz down slope is being damped by them. I’ve also replaced a heavy curtain with a dense string curtain to allow HF sound to diffuse off the TV better and not all be absorbed.
I’ve learned a lot, and while I’m not as practiced as those who can pop in a CD and tune from ear, I’m getting to a point where I can predict an FR graph given what I hear. At least I now know why my dealer said my system sounded dry.
I commented in another thread it’s hard to know where to go if you don’t know what you don’t know, so another big part of this was self study and experimentation.
I hope this helps if you look into trying your hand at it.
Edit: I also found attenuators in my chain, whether the in built DSD attenuator or an inline Rothwell to damp decay time. There is an interaction between rendered decay from speakers and room decay to balance and I found no attenuators best in my room.
Edit2: one of my tests for microdetail is the first several measures of Welcome to the Black Parade. My system now resolves the metronome ticking away at normal volume.
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I ordered two very expensive Stealth power cable and two absurdly expensive XLR cables for the amp. I’m talking >$20k for the four cables. Add a $4000 stand and special feet and yeah, it’s a bit over $30. I haven’t powered it up yet. I am waiting for the rest of my gear to show. I have to disassemble both my current rig and my home theater rig before I can start placing the new gear in its space. I am patient.
I wasn’t actually shopping for any new gear. I just saw and heard some stuff I liked and things kind of took of from there.
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What a detailed procedure. Thanks for posting!
I know how you feel. These things happen.
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I totally get it. I was in Whole Foods buying vegetables and some hemp seeds and I saw raw pumpkin seeds and I thought: this looks good.
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In keeping with the theme of this thread and much to my wife’s consternation, I did make an unplanned upgrade. It started with someone near me looking for a pair Wilson Audio Watt/Puppies. Simultaneously, my Local friend and Wilson/PSAudio dealer let me know about an as new Sasha that was landing on his loading dock. All things moved quickly and I’m now the ecstatic owner of a pair of gorgeous looking and sounding Sasha’s.
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I purchased a pair of M1200’s from the Music Room and one arrived today. Thanks FedEx. Hopefully the other will arrive Monday. I have hooked up one for about 5 minutes of music to compare to my existing M700. I’ll post my limited review so far on a M1200 thread.
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I’ve been thinking about moving to fewer components to free up some space and I mentioned it to my dealer when he delivered the Stenheims.
I just got off the phone with him and he’s going to lend me the CH Precision I1 and Vinnie Rossi L2i-SE integrated amps to audition.
This ought to be interesting…
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@Vee,
This has your name written all over it given how you like to optimize. The equalization curve pen would give unlimited permutations sans the tweaks.
Someday when i can afford a McIntosh big boy two box preamp and I leave Lyngdorf DSP behind…
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Wives can be troublesome.
Just last week I was having breakfast with my wife and I meant to say:
Please pass the syrup
But it came out:
You b*tch you’ve ruined my life!
It could happen.
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But you meant to say that to a bad sounding piece of audio gear, right?
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You left out the most important point.
Was it pure maple syrup?
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Well that post cost me a lot of money for new audio furniture.
Thanks though.
How big of a difference was there between the P10 and P15? I am looking at both on the used market but at 2k-3k price difference, I need ask is it worth the extra cheddar?