SR Black Box

I had the opportunity to test the Synergistic Research Black Box during last weeks.
Let me thank Al for his precious advice, I’m not a big fan of SR products but I trust in our mentor, as many others here.

Here my thoughts.

The best result was easy to find after a few experiments on the corners of the front wall and on the side wall. In the center of the room, between the speakers, a little bit forward the baffle line.

This is the most relevant area where the box can bring improvements. Pretty obvious because is designed for this purpose. Bass became tight, very tight and speed. The box removed boominess creating in that area a refined texture, more distinct, clear and with lots of informations that were unheard before. Basse are now going deeper easily and pleasantly.
But I’m not so sure that bass are the only area that I’m liking now.

It was unexpected the result that better bass have brought to other aspects of the music. Looking at the 3 soundstage axes I can hear pretty the same width, a little higher image and certainly a different depth. Here the difference is not subtle. Live albums for instance sound so real, providing a feeling of the dimension of the space very distinctive. The distance of the performers and instruments on the stage is incredible, so easy to perceive.
It reminds me the laser light penetrating throughout the smoke fog wall on a concert. You get the depth, you see the depth, you feel the depth with all your senses. You breathe the layers of the air.

All the changes above described have also enhanced the realism of the image projected in front of the listener. The color and tonality are unaltered but the intensity of the music got a step up, lifelike and involving, realistic. The so called “to be here” effect is one of the quality that impressed me more. The scene is more three dimensional, credible and coherent as it should be in high fidelity experience. The evil is in the details: the movements of the head of the singer (what? Yes!), the shape of the instruments depending on their position and distance between each other, the perspective from where the second voice comes and how far in respect of the main singer.

I love the improvement that cables can make to the system, I heard difference from fuses and tubes, I experienced how a blacker background can elevate the sound quality and the pleasure of listening to music, thanks to switch/filter/ground tweaks.

Here there is a different result, maybe the room itself seems to sound better, more in harmony with the music. I had the same idea when I got that late at night it was more enjoyable than during the day, if it makes sense.
I noticed also that I could easily play music for hours with the volume two steps above my usual level, without any distortion or loss of naturalness, warmth or relaxation. Only pleasure.

I need to test the black box in many other positions but I’m liking so much what I’m hearing that I don’t feel the urgency to do that, for a while.

I’ve also started experimenting with the SR HFTs (AKA Funny Buttons) and I have to admit that they work fine, too. Mainly in conjunction with the Black Box. But this should be the next review to come.


Many thank yous for your review. Your comments about bass and depth are encouraging. I am amazed what it can do, all without cables or power. I will buy a SR black box.



I was just looking at those widgets and wondering if they could possible do anything.

Obviously they do and thanks again for your excellent review(s).

Not sure if I will go down that road or not but it is interesting that a small passive device can make that much difference in a well setup room like yours.

That should help to tell us how much we still don’t know about what we don’t know.


You should thank Al, he first mentioned this box a few weeks ago. He said it sounds nice! He tried also with more boxes in the room.


I was wondering if that is what he was testing but I really did not want to know. At least until I recover from holiday expenses. :rofl:


Al and I were sitting together in the SR room at axpona last year. Neither of us wanted to believe what we heard. There was three black boxes in the room and the sound was very good coming from the Estelon speakers. When the SR dude started to remove the boxes one at a time the change in sound quality wasn’t subtle. The bass became muddy the accuracy was off and pace seemed slower. Then he bought them back in and we said some profanity that’s not allowed on the forum but imo SR’s most obvious product that works without a doubt.

I had an opportunity prior to Christmas to borrow @straightwire black box and once I removed it sadness followed. What @luca.pelliccioli describes is spot on accurate. My systems PRAT improved dramatically I’m hearing more detail that was more than likely getting covered up by muddy low frequencies. The detail and texture on stringed instruments and the sound of the skin on the drums is palpable. It’s hard to describe until you experience it for yourself. I had it positioned between my speakers for the best result.


Thanks, Paul.

If I’m not wrong Al said (after testing 3 of them together at some home friends) that one BB is enough. He has 2 BBs. As per your post you heard 3 of them in that room, do you agree or do you think more than one could be a good idea?


One is magical at my place. I didn’t hear a difference with two boxes positive or negative. Al has two and we placed them in several spots in his room which benefits from two. @straightwire may of compared two vs one also. Juan who is Al’s SR guy told me other than the black box the newest model Carbon tower would compliment the black box very well. I’m scared to hear it myself.


Busy packing and winter travel is always more headache since our clothes are taking a lot of room already. But I do not want to leave without commenting on your great review.

Between the black box and PSI C214 cylinder, I may have to get one of them eventually. It seems like it works well based on your and Al’s review. In fact, I have not found any review saying these are useless yet (unlike Al’s black tower :laughing:).

I have a feeling the cylinder in white will be more acceptable at this house.


If I recall the third box at Axpona didn’t make much of a difference when added over the first two that were in the room already.


Positives of the black box- it works for most and no power cable and no fuse!
Negatives of the black box- Expensive and frustrating when you realize you have to have one. :cry:


The Cable Co. can give a tidy discount I assume. But I do not know if I will have any penny left after our Japan trip. My wife has a pretty long wish list built up. :open_mouth:

Have a nice trip to Japan, my friend!

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I agree with you.
What I don’t like about that is the need of 2 wires/sockets (ground + switching). I’d prefer passive vs active tweaks. Can’t understand also if a correct positioning could be an issue (for instance on the side wall close to the rack and NOT on the front wall between speakers).

Awaiting our mentor opinion.


It would be interesting to play with the black box and the Theoretica Bach4mac Optimal Room Correction. And see if the curves with and without the black boxes. I know even digital cable swaps changed the head transfer function curves. A lot of what is described sounds similar to engaging and disengaging my current Room Correction software Room Perfect or switching from a room average correction algorithm to focus listening position algorithms. If one is opposed to computers taking care of it. The black box sounds like a more expensive passive solution for those using DSP. But zero passive treatments and DSP is usually inferior to combining DSP with good room treatments.


I will be able to test that later this week. I believe I will get the new version Tuesday or Wednesday.

Nice review Luca!!!

If you are living in the US I have a friend who can fix you up with a Black Box with a nice discount.


Luca, I had two Black Boxes at my place and I kept one. The improvement with one was similar to yours, in a similar position between the speakers. I could not detect any real change in the second, that was positioned to the side and rear of the listener. I consciously did not want the second to work, so that bias might have been in play as well. My room is fairly small as that could be in play as well.


I read that the leading edge bass notes are a bit exaggerated and the highs are lopped off above 8k as reported by some users…Anyone agree?

Anyone have any before and after measurements?

what’s inside the box

take it apart and tell us

what’s inside the box