Hopkins' System

hopkins

Well-Known Member
Sep 10, 2022
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Paris
paulstephane.github.io
Hi,

here's my system in action:




Full system is: LMS "server" on a desktop computer, RaspberryPi with Ropieee is the "player", connected through a basic USB->Toslink converter to ECDesigns' powerDAC-S. Speaker cables are SilversmithAudio Fidelium. Speakers are custom open baffle with TangBand drivers, based on ECDesigns' "design".



Enjoy!
 
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Here's another video with a slightly different mic placement and volume adjustment.


The mic is a little closer to the speakers than my listening point. The voice is well captured but the sound is slightly more forward overall (could also be a level issue). Recording is an art which I do not master!

Here is another recording of a more contemporary recording, with the mic at the listening point.

 
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Way to think outside the box.
 
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In the past months, I have struggled to find the right placement for these open baffle speakers in my living room. I always felt that something was not quite right and that the placement was not optimal. It has been really frustrating!

At last, after moving some furniture around to free up more space around my speakers, I have found what I consider to be an optimal placement. It is striking how small differences in speaker placement can have such a large impact on perceived sound quality. Once you get it "right", everything falls into place: instruments are accurate in their tone, attack and decay, soundstage is wide with accurate instrument placement as well. The sound is "full", yet detailed. Sound is "natural".

Here's a sketch of my living room, with an approximate placement of my speakers:

LivingRoom.JPG

I tried placing the speakers facing the length of the room (along the wall on the left), but could not get good results. The furniture got in the way, and perhaps the differences in depths of the wall gave poor results.

The speakers (in red) are facing my couch, forming a quasi-equilateral triangle with the listening point. I have two thick square GIK acoustic panels that I place on top of my couch, just behind my head, and while they do not affect the frequency response much, listening is a little more relaxing (for my 56 year old years) with them.

I took some measurements. Here is the SPL with 1/24 and psychoacoustic smoothing:


spl 1-24 smoothing.jpg

spl psychoacoustic smoothing.jpg

Obviously, there are some refelections and room modes causing a few dips here and there, but nothing serious. This is, after all, a living room, not a recording studio!

Bass extends down to 40hz, which is fine by me, and the response is pretty darn flat up to 20kHz. Above 10k, the response is highly dependent on the height and distance of the ears to the speakers, probably as a result of the line array topology.

I will detail all this in my blog, and post some additional videos in the coming days.
 
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Great to see a fellow hard jazz fan.
Do you have a cat? I thought I heard one in the background. Ice tinkling in a glass also.
 
I installed Hofa acoustic curtains today - double layer, "studio" model. It covers a large window (220x220 cm - the curtain itself is twice as wide) behind my speakers, so facing my seating position.

Acoustic curtains are a really good solution, IMO, when panels are not an option. They obviously will not solve any bass issues.

I'll take measurements at some point, but it does seem to have a very positive effect, enhancing the sound quality of the system.
 

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Recordings do not capture fully the sound of a system (not because of youtube compression, but due to microphone/recording quality, and obviously the system used to listen to the result), but they are fun to do, and interesting at least for me. So here's another one:

 
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Curtain.jpg

To further optimize sound quality - without permanently turning my living room into a man-cave (I do not have a dedicated listening space) - I devised a system to hang an acoustic curtain (3 layer Hofa studio model) behind my listening position, which can be installed and removed in less than a minute. When not in use, the vertical bars are stored under my couch, the horizontal bar folds in half and the curtains roll up around it so I can store them in a corner. The improvement in sound quality is quite noticeable, and I am happy with the results! :)
 
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The removable curtain above the couch was not practical and the sonic benefits not that great. I opened another topic on the forum to seek advice and got some very interesting suggestions which I implemented and am very happy with. The solution consisted in treating ceiling reflections with vertical panels.

Many thanks to @pjwd for his time, invaluable advice and expertise!

Here's a picture of my DIY prototype...

PXL_20230529_170034036.jpg

5cm thick PET panels are attached to the ceiling, spaced 12cm apart. I will be getting custom made panels and professional help to install them. I may put some LED strips as well.

The improvement to the sound quality was surprising, and I am very happy with the results. For the reflections from the wall behind my listening position, pjwd suggested simply a convex cushion just behind my head (not shown in the picture), and this also works well.

I will probably hide some absorption material underneath some of the furniture as well, after I finish refurnishing my living room (ex: the couch, a part of which I have to rotate in order to get it out of the way of the speakers).

I tweaked the placement of the speakers, moving them a little closer to each other and further into the room, away from the side wall, which reduced resonances and tightened up the bass.
 
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The file is being played back using ECDesigns' UPL, which is a minimalistic WAV file player.
ECDesigns, as noted on the corresponding thread on AudiophileStyle, will soon be releasing new versions of their products which will include some significant improvements. Stay tuned!
 
Here is a short presentation of my custom music management app, which is connected to ECDesigns' UPL for music playback (and playing through my desktop speakers for the occasion):


It's all web based so it also works on my tablet/phone.
 
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