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Tweaking Sound with Convolution

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I have attempted many different kind of tweaks to improve my sound. Cables, tubes, HiRez, power conditioner and stabilzer, cones/spikes. One on occasion, I even submerged the speakers stands in water and sand bagged them with fine sand....... dedicated power supply from solar panels. Far too many to mention here.


My current system is rather simple and the best tweak I added is the convolution channels for the stereo playback. The additional price I paid is just about $600 to get the additional twenty over speakers and DACs. I got these.....




These addition now allow me to experience far better improvement  as can be seen in the videos below.


These videos were made in my room from my listening chair using a cheap binaural microphone (Roland CS-10EM). You have to use headphones to hear the changes. Due to 18 additional speakers recreating the ambiance by adding to the main speakers, the sound played directly through speakers can be muddy and congested and therefore use headphones to hear closer to what you would hear at the listening seat. Due to the limitation of the $75 microphone, the high frequencies are too bright. It also failed to capture the low level ambiance.


Some points about these videos:-


1) No changes made to the files. All were recorded in 24/96 format and uploaded as such. However, youtube would have compressed the audio.


2) They were recorded using Zoom H1 recorder connected to Roland microphone. Level was set at 90 of 100.


3) The actual music level while making this recording at  about 214cm from the main speakers were Avg =  76dB and Peak at 87.5dB.


4) The actual preference is convolution at 50 or 80%. In this video, the first one was at 50%, second one at 80% and the third at 100% level which I use for large orchestra music with high ambiance content. 


4) This setup is my early attempts to recreate the 3D concert hall ambiance in small space. I will add more info about this later.


6) You may hear slight timing difference due to my omission when changing the default values when doing this demonstration videos.


7) You may hear the air conditioner which is getting a little noisier lately. 


8) The videos below are to show the effect of convolution. See here for proper use of them.








See here for proper use of them


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Thanks for the feedback.


The purpose of the video is to show the effect of convolution and how it alters the sound. For music like Mad World the convolution should be turned off completely. I wanted to show the effect but we are quite aware of the well like effect of what's coming out of the cheap microphone recordings. 


I am am not really keen with violin or saxophone as it tend to hide room flaws. On the other hand piano is difficult to be captured. Norah Jones is very good but I cannot capture the soundstage. Will see what recording can be used. This another Hifi system playing Mad World. 








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They were meant for very low volume convoluted sound. Fidelity is not important there and I will be adding more speakers and separating the cables would be impossible.



Anyway, the above video meant to show the difference caused by convolution. The effects were exagerated. Below is two sample one with Convolution for music without much ambiance and another one for classical music and added with convolution.




And Brahms - Sonata for Violin and Piano.



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Thanx for feedback. But this is a clear example, that Youtube cannot replicate what the system sound is accurately. It can show room flaws but it will not reveal everything.  Let alone to use that to pass judgment of stereo setup recorded miles away from the sweet post to tell how good a system is like what you do. Is it so difficult to reduce the gain from the sweet spot and make a video?

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1 hour ago, fas42 said:

This is good ... you're motivating me to get the NAD combo up and running again - it's working without a volume control at the moment; as I point out in my blog this was a significant quality weak link. I've got a replacement, which I've been "too busy" to install, ^_^. So, stand by ...


I like to believe that you have something to offer but I am not getting it. Trust me, if someone were to post saying that placing a bucket of water in your room would make your sound more natural, I will give it a try and then look for the scientist explanation (caveat- it doesn't mean I will do everything). :)


So please show us something tangible.

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11 minutes ago, esldude said:

BTW, was this recorded with the Roland CS-10 EM microphones?



Thanks Esldude for the feedback. 


Yes, it was recorded with CS-10EM. I thought I had a recording of it playing through the loudspeaker because I use this track to setup my system. Will make another one and see how Youtube is distorting the soundstage.

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26 minutes ago, fas42 said:

Note that the bird song sounds "real", and there are background sounds to it as it progresses. Now, play the original quality version of this through the system, and record that with the same microphone setup ...


Don't be too sure, I could have uploaded my system's playback! 

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1 hour ago, unbalanced output said:



The issue is to create cross-talk between the channels due to the induced currents. Cross-talk affects the sound you want to create. Hopefully, at low volumes this is not significant however something to keep in mind. 


I tried to listen to the youtube videos however as elsudde pointed out they doesn't seem to make much sense. 



I am am not sure what crosstalk you are referring to. There are many videos there. The first three and after that another two. 


According to Google analytics the average time viewers spent on the these videos was just one minute. With such a short time many would have missed the notes in the video. 



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Looks like it is impossible to capture the illusion created by two speakers with binaural microphones.  I find this very strange because the microphone is not capturing the sound as how we perceive them. There must an explanation. One that I can think of is the close proximity of the two speakers. They are almost touching each other and the bigger than stereo soundstage is heard because of crosstalk cancellation. See the picture below.






 Anyway, I made another attempt by putting a divider in front of my face and I used a pillow. I got better separation but the front stage sounded muffled . Then I used a small block wrapped with cloth. So the result is slightly better. As per post one, the recordings were done from my listening chair. A total of 20 speakers were playing simultaneously for this recordings.


Norah Jones' Come away with me.





And the other two are  2L Lindberg test recordings.






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Made minor changes by toeing in the speakers inwards and brought down the elevated rear speakers to ear level. I believe that speakers are causing the previous records to sound fous in the middle. But still a $75 binaural microphone cannot capture the exact sound. IMO, the best upgrade was the SIR2 convolution DSP. It reduced the CPU load from 25% to 5%. It sounds better if you use headphones.




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1 hour ago, fas42 said:

This is sounding good ... I play your recording, and then the actual source track, available on YouTube - no obvious issues - nice one!


Thanks for compliments but the recordings is still not projecting what I wanted to convey.


The strangest part of this was we couldn't tell any difference after making the changes but when we compared the recordings the difference was obvious. Looks like our brains are capable of filtering away unwanted sound of the elevated speakers in the earlier setup when listening in the room but could do it when listening with headphones of the binaural recording.

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