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Feedback on 2.2 coffee table system measurements

VanO

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Joined
May 15, 2021
Messages
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Hello! I'm still pretty new here but I have enjoyed learning a lot from you fine folks. I’ve decided it’s time to get my tunes away from the computer desktop so I’ve had some fun over the past few months putting together this 2.2 coffee table system. I’m trying to do some fine tuning on it and I’m still learning my way around the Umik-1, REW, and a lot of this stuff.

My room is a carpeted concrete floor den (old garage converted). Standard look from the 70s with knotty pine paneling. I’ve done some experimenting with toe-in/out, tilt, and matching sub levels. The LP is on a leather couch 44” from the main speakers (Dali Spektor 2s). Ear level hits right between the tweeters and woofers. The Spektor 2s are 34” apart at the centerline, toed out and tilted down about 3 degrees, and on 6” Kanto stands.

I have a 6.5” (L) sub under the coffee table that is centered below the Spektor 2s. It's on rubber feet on a wood plank. The plank is also on rubber feet and everything is coupled between the floor and coffee table (3/4" of foam padding between the sub and table dampens vibrations).

I have an 8” (R) slimline sub centered and directly under the LP, and slightly forward (36” between sub drivers). The couch is lifted on bricks and foam pads and the sub is coupled between it and the floor. I have a tactile bass shaker mounted directly above it on a plank I installed and I run it at a minimum volume to enhance the 8” sub and put a little more punch around 60Hz.

I’ve got a good soundstage and have adjusted everything to where you can feel the bass but it’s not detached from soundstage. It very much feels like a cone or pocket of sound when you’re in the LP. I can get and feel a high volume without disturbing the other end of the house.

I don’t know what a lot of the things mean on most of these graphs. I’ve worked out the phase of the subs and the crossovers the best I can from listening tests and also taking measurements, it sounds very good to me. I’d appreciate any feedback on what you see in the graphs and what a lot of it means. Thanks!

I’m using a UMIK-1 and REW 5.2, and I run Qobuz and Audirvana Studio on a Mac Pro. I use an iPhone as a controller with the Audirvana remote.

I use SoundSource to input PEQ filters and then test measure back in REW. Final PEQ filters I apply in Audirvana.

System

• Mac Pro (Mid 2012), 2 x 3.46 GHz 6-Core Intel Xeon, 96 GB RAM
USB 3.0 to >
• ifi Zen Signature Dac (volume switch set to "variable" for overall system control)
RCA to >
Bellari EQ570 (2 Outputs)

EQ570 Output 1) RCA to >

• Rolls SX45 Stereo Two-Way Crossover
High pass to >
• Aiyima Tube A3 preamp (OPA1656)
• Aiyima A07 amp #2 (OPA1656, 48v 10a PS)
• Dali Spektor 2 speakers (ports plugged)
Low pass to >
• Douk Audio G4 amp (24v 6a PS)
• Dayton Audio BST-1 Tactile Bass Shaker (phase: 0)

EQ570 Output 2) 3.5"/RCA to >

• Rolls SX95 Stereo Subwoofer Crossover
RCA to >
• (R) Theatre Solutions SUB8S 8” Slim Line Powered Subwoofer (phase: 180)
• (L) Acoustic Audio PSW-6 Powered Subwoofer with a Dayton Audio DCS165-4 6.5” Classic Subwoofer Driver (phase: 0)
Pass thru to >
• FX Audio Tube 01 preamp
• Aiyima A07 amp #1 (OPA2134, 32v 5a PS)
• Pyramid Tweeters (2.2uF caps)

Center EQ All SPL.jpg


And yeah, I like a bit of a smiley face. My audio systems for decades have mainly been in autos. I checked a couple of days ago and my listening level in the car is 93-99db. There are basically eight drivers in this system in a small area, and it gives me that same feel but with a nice soundstage.

I think the Pyramid tweeters widen my soundstage a little and emphasize the cymbals more in the kind of music I like to listen to (AC/DC, Led Zeppelin, The Who, Stones, Skynyrd, Hendrix, SRV, ABB, Clapton/Cream, and Johnny Cash : ). I beefed up the padding on the base so that they can be coupled to the metal Kanto stands beneath my main speakers. I have them angled out about 30 degrees and up about 5 degrees. It took a little experimenting to get that set but they integrate well.

I'm thinking the big dip at 400Hz that you can see in the chart below is from a wall that is 16" to the right of the center of my right speaker. Center LP is 31" from the same wall and you can see in the measurements the valley dips more the closer you are to the wall. Left, Right, and Center measurements are 6" apart. Next time I do some measurements I'll put something up to see if it is a reflection and if I can absorb it some.

LRC, No EQ All SPL.jpg
LRC, No EQ All SPL.jpgCenter No EQ Phase.jpgCenter EQ Phase.jpgSpektor 2s EQ Phase.jpg2 Subs EQ Phase.jpg2 Subs +Shaker EQ Phase.jpgCenter EQ Distortion.jpgCenetr EQ Group Delay.jpgCenter EQ RT60.jpgCenter EQ Clarity.jpgCenter EQ Waterfall.jpgCenter EQ Spectogram.jpg
 
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OP
VanO

VanO

Member
Joined
May 15, 2021
Messages
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I went back and started the process from the beginning again. I realized in the measurements above I messed up the crossover on one of the subs. I also worked on mitigating some of the reflections and it worked pretty good. Check out the difference on the dip at 400Hz.

LRC MMM No EQ.jpg

High Pass Spektor 2s.jpg
Drivers XOs No EQ.jpg
Center EQ No Smoothing.jpg
Center No EQ vs EQ.jpg
Drivers and XOs Final EQ.jpg
LRC MMM Final EQ.jpg
Center EQ Phase.jpg
Distortion.jpg
Group Delay.jpg
Clarity.jpg
Waterfall.jpg
Spectogram.jpg
EQ Filters.png

One interesting thing that I learned is that in a nearfield setup like this (especially since it's on a coffee table and lower than a typical desktop system), your body (or lack thereof in the LP) can make a difference in the reflections and frequency response. Originally I had the mic in the listening position with all of the leather exposed where I would be sitting. I put a foam chair cushion against the back of the couch where my torso would be and put some folded towels covering where I would be sitting. That knocked out 1-2 decibels of the 400Hz dip. I reduced it a couple more decibels by putting up some room treatment for side wall reflections. I also moved the speakers/stands forward a little which reduced the reflection from the surface of the coffee table a small bit.
 
Last edited:

ernestcarl

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Joined
Sep 4, 2019
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I went back and started the process from the beginning again. I realized in the measurements above I messed up the crossover on one of the subs. I also worked on mitigating some of the reflections and it worked pretty good. Check out the difference on the dip at 400Hz.

View attachment 153472
View attachment 153473View attachment 153474View attachment 153475View attachment 153476View attachment 153477View attachment 153478View attachment 153479View attachment 153480View attachment 153481View attachment 153482View attachment 153483View attachment 153484View attachment 153485
One interesting thing that I learned is that in a nearfield setup like this (especially since it's on a coffee table and lower than a typical desktop system), your body (or lack thereof in the LP) can make a difference in the reflections and frequency response. Originally I had the mic in the listening position with all of the leather exposed where I would be sitting. I put a foam chair cushion against the back of the couch where my torso would be and put some folded towels covering where I would be sitting. That knocked out 1-2 decibels of the 400Hz dip. I reduced it a couple more decibels by putting up some room treatment for side wall reflections. I also moved the speakers/stands forward a little which reduced the reflection from the surface of the coffee table a small bit.

Difficult for me to imagine what the exact room setup is like (too many elements involved for my brain, sorry), but most of the measurements look fine. Apart from the two anomalous traces I marked up below, I probably would have just shelved some of the HF energy, but that's me.

1632256951430.png
 
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