I know someone who built an atrium around a Fiat Topolino that has a deep personal connection to him.
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And I think my Pass X250.5 is a hernia inducing back breaker. My my. I’ve had this design idea rattling around my head for years, might be a cool retirement project (on paper at least). A monster amp moving/transport system with wheels for positioning the thing where you want it. Then a wheel retraction system that at the same time lowers spikes to lift the monster off the floor for isolation.
The insane stuff a bored scientist/engineer dreams up in his spare time … ah well there are worse obsessions. 
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I’ve been on a bit of a mod, listen and measure binge. Some things I’ve done in the past week… 28 REW sweeps on a number of combinations:
- #1 6922, 2x back wall bass traps, on spikes and disc, Shunyata Python Zitrons speaker cables; baseline measurements
- 6922, same as above but without discs under spikes; bass out of control (sweep deleted for this dead end case)
- #4 12AU7, same as above; 12AU7 very slightly recessed, less noisy
- #7 12AU7, Stenheim on GreatGRAMMAS; big change in mid-range, not good; loss of cohesion, PRaT. My dealer advised not to put the Stenheims on Gaias, but I wanted to hear what more damping would do. Bad idea.
- #10 6922, removed 2x back wall bass traps; everything took a step up, mid-range clearer, highs are clearer; very good; new winner
- #13 6922, placed speakers, spikes, disc on 2x heavy tile base; more mid-range definition; new winner
- #16 6922, removed discs; no remarkable change; speakers easily move on tile; bad idea
- #19 6922, replace Iconoclast with audio envy IC at DSD; more body; some micro dynamics like very faint echos now audible; new winner
- #22 6922, replace Iconoclast with AE IC at BHK300; more upper to high end presence (triangle instruments ring just a tad bit longer to be noticeable); faint echos clearer; CURRENT SETUP
- #25 6922, replace Shunyata Python Zitrons with Audio Envy speaker cables; step back, loss of PRaT, loss of body
I think I’m done for now. Very interesting things learned. The overall impact of setup number 22 over number 1 are:
- Everything has more presence, and a different kind of separation, like their overtones and resonances carry on a little longer as other instruments are playing so there’s more overlap of various decaying sounds – this creates a different kind of space, more ambiance, less isolated spaces
- Certain micro dynamics are now present when they weren’t before: extremely faint creaks, very light string buzzes/scratches
- Very PRaTy… The foot tapping kind. Kicks, Toms, etc. have more punch
- Bowed and plucked strings have more weight, body without sounding heavy and accentuate more clearly
And here are the sweeps. Baseline SPL was equalized to about 85dB for all of them. These are separated for ease of seeing each FR curve.
Here’s #1 vs #22 superimposed:
What’s next?
- Trying different spike discs: carbon fiber, heavier steel; there’s a subtle difference in the mid bass and mid-range from differing spike supports.
- New English Electric 8Switch network switch inbound
- Ring in the New Year. Hopefully a very big upgrade there!
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A bit flatter response and improvements in the dips. What is your end run goal on the curves and what do you want to cure next?
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I don’t think I could go flatter without changing rooms, orientation or adding DSP, which I’ve avoided–and that would probably negatively impact what I’m hearing. A 3dB drop along the mid-range from the GreatGRAMMAS really destroyed the balance of sound and set the center stage too far back in relation to the left and right. Maybe I could rotate everything 90 degrees to place the speakers on the short length of wall, but I would have to move the also very useful massage chair out of the room.
What set me off in this direction was noticing some micro dynamics show up when I swapped out the IC SPTPC cables. From there, it was just changing things up to see what the sound was like with what I had on hand – and recording the measurements for posterity. There are other graphs I’m looking at which I don’t describe here.
For example, removing the rear bass traps didn’t affect bass, but did improve mid-range and highs. It also let sound decay for a little longer, and group delay and spectrometer graphs showed slightly longer decay times, which translated to a slightly larger sounding stage to my ears.
This was an exercise in correlating what I heard with what was being measured, and these changes had meaningful impact. What the graphs don’t show are the very nuanced sounds, the slightly longer ringing of a triangle or very subtle scratch of a string buzz.
Overall, I feel like it’s in a pretty good place. The other changes were simply on their way and haven’t arrived in time for this write up.
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That is a lot of info to collect and track. I would have gotten side tracked midway through the exercise. Nice job.
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I focus on the real sound of the voice. It has such range all the spatial nuances come along.
It is a pretty good curve. I like my low bass a bit higher. Any chance to move your listening position forward or aft to see if your in a null. I also try to see what each speaker is doing at 1 meter. That will tell you a lot about balance and speaker performance or bass suck out versus your listening position.
Try as I might to do with out DSP t is a necessary evil. In mine only takes away dB versus add.
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Good points, I will try these suggestions. Thanks!
I focus on the voice too. We’re most sensitive to problems with the voice. It’s been around much, much longer than any other instrument.
My room is problematic. I’ve embraced DSP but only at double-precision floating-point format. Namely convolution and adjustable (effect and sense) time-based bass resonance control both are active ~600Hz and below. HAF Room Shaper.
I’ve spend considerable time with placement, delay and xovers to get it as good as it can be prior to measuring and applying DSP.
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Some focus on piano because of the difficulty to reproduce it well and the range of the instrument.
My wife being a singer, I focus on voice too. If I can get my system to sound close to her on CD, I am doing well.
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For me I focus on bongos. I love bongo music and it’s really a lot better when done well.
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Share the title?
I use flac files of a singer I know personally well who also has been in my audio room and the group he is in I have seen live. You are fortunate to have CD of your wife and a voice truly embedded in your memory and be able to hear het voice in your audio room.
What’s your reference.? I do like some Carlos Santana Marathon Album. But I’d be lying if this did not flash through my mind first when I read your post.
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Good point Brett, but Jodi is not that famous. She has done a couple of local studio CDs and she is in a Band called Maltbie Wood.
Her brother, mother and father are all singers so it must run in the genes.
Indeed, we are fortunate to have good music / sound references!
“And bongo jazz, a speciality…”
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Room acoustics and speakers.
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