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Post by Deleted on Nov 18, 2019 19:28:34 GMT 10
This is a write up about some Synergistic Research (SR) frequency-equalizer technology (FEQ)'s that I bought recently. Discussions on the FEQ (and let's face it, everything that SR does!) seem to result in the great bulk of people savaging the company and their devices and then a small percentage of people who own them who love them. Then there is that minuscule proportion of people who have used them and didn't find that they worked. So it's a brave soul that brings them up on a forum, especially ones that are bastions of objectivism. The FEQ is a device that is made out of metal that is about 12cm X 12cm in footprint and about 20cm high. It runs off 12V DC (though i did get them to run off 5V too). They seem to emit no noise, they do not perceptibly vibrate and they have no apertures. They are tiny and I can see why someone would consider them snake oil as they seem to be expensive, pretty boxes that must have some placebo effect on impressionable audiophiles. In an attempt to meld together the subjective with the objective, I've been testing the pair of FEQ's in my room with: 1. Measurements. 2. Blind tests (single blind). 3. Subjective listening and observations by multiple people. 1. Measurements. Well I'll do this first as the results surprised me. I didn't buy the FEQ's expecting that they would have a profound or necessarily positive effect. Call me an audio fool but the only way to verify if something really is effective and positive is to try it yourself, in your setup. I like to try the occasionally tweaky device. Sometimes they work, sometimes they do nothing that I can hear and sometimes they do work but I don't like what they do. My setup is a Tascam US-1x2 (USB mixer / 48V power for the mic') with a isemcon reference microphone set at my listening position facing directly towards the middle of the speakers. I have an active Bass-trap in my room (AVAA) which was switched off for all tests. After listening with the devices ON and OFF, I was keen to try measurements to work out if I was imagining things. Or at least work out what the hell these things were doing. So getting straight into it, here is my room measurement with both speakers being feed with a sin-wave in REW:  I did a number of measurements which were very consistent so these graphs are 2 that I picked that are representative of the samples. There is very little difference above 70hz but there is a marked reduction in bass below of about 5dB between 15hz - 35hz. Interesting. My experience and the physics of bass reproduction in a room is that an object this size should not be able to exert this type of influence on bass in a room. I have used passive bass traps and 2 types of active bass traps which all had positive effects in my room. A passive bass trap is usually quite large and the active bass traps both have an aperture to let bass waves in then some sort of powered membrane. But there it is. You can switch the unit on or off all day and repeat the measurement with the same effect... |
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Post by Deleted on Nov 18, 2019 19:47:52 GMT 10
Next I'll look at other analyses of the results. Since the FEQ is meant to have an effect on all the frequency range, I'll look at the entire spectrum in all these graphs: \ Clarity  Clarity follows a similar pattern with the mains improvements being in the bass region up to about 100hz. There is a very minor increase above this frequency. |
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Post by Deleted on Nov 18, 2019 19:52:52 GMT 10
Next is an RT60 (R30) - please see here for an idea of what this means - www.roomeqwizard.com/help/help_en-GB/html/graph_rt60.html Essentially, the lower the line on the graph, the faster the delay (better):  There is an improvement up to 150hz. That might simply be a result of there being less energy in the low bass region. |
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Post by Deleted on Nov 18, 2019 19:56:10 GMT 10
Here is a spectrogram of the energy in the room over the frequency range over time:  Pretty picture. Actually pretty bad as my room is shocking (it's got hard surfaces and is 3.9m X 4m X 2.9m high). |
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Post by Deleted on Nov 18, 2019 20:00:45 GMT 10
And now here is the Spectrogram with both the FEQ's on:  Bass energy is still there but seems a tad less density in the bass region. One repeatable phenomenon in the spectrograms that I have noticed is that the FEQ's increase the decay time by a small amount at higher frequencies. Interesting. |
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sandyk (RIP Alex, 1939 - 2021)
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About Me: Retired ex Principal Telecommunications Technical Officer with 43 years at Telstra (Australia)
I am also a Moderator in Hi Fi Critic Forum
Electronics hobbyist for >65 years with DIY projects including Loudspeakers, Stereo FM tuner, S/W Regen Receiver, Superhet AM ,
Synchrodyne PLL AM tuner (Phase Lock Loop),Stereo Tape Deck, Amplifiers including I.C. types, Class A, Class AB 100W/Ch. (ETI5000) 240W/Ch. Mosfet (AEM6000) ,several DACs , numerous PSUs including VERY low noise (<4uV) types etc.for myself and friends
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Post by sandyk (RIP Alex, 1939 - 2021) on Nov 18, 2019 20:03:12 GMT 10
Hi Scumbag
Where do you believe all of this spurious LF energy is coming from ?
For example, would it be much lower in a Rural area, and perhaps much higher closer to a Motorway ?
Regards
Alex
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Post by Deleted on Nov 18, 2019 20:20:40 GMT 10
Blind testing:
I roped in a range of people to listen to the FEQ's in a loosely controlled single-blind experiment. Yes it was very informal and I'm sure people will ignore it but I got a very consistent range of comments from people with no prompting. I am not going to put this forward as evidence because I'm more interested in the correlation between people's unprompted observations.
Most people could tell when the units were on or off. One guy initially struggled but we revisited the tests and got a better result.
Subjective comments:
When the units were on people commented that there was an instant and noticeable change in the width of the soundstage. It actually seemed to narrow the image or at least make the centre image (vocals) more focused.
Another common observation was that the bass seemed to tighten up or improve with the units on.
2 of the people tested noted that the soundstage shifted. In one case one observer noted that the midrange seemed to project outwards from the speakers.
About half of the listeners felt that the sound was definitely better with the units on. Some observers were undecided about whether the units improved the sound of the system and felt that they needed some time to get a grip on the effect they were having. One listener (the same guy who struggled to hear their effect that I spoke about above) felt that they weren't having a positive effect - he actually said that they would be really good in low resolution system and that my system sounded better with them off.
My subjective observations (totally sighted):
I noted a change in the soundstage. There was a definite widening of the soundstage and the midrange became slightly less forward - a bit of a surround effect or a tube effect depending on where the units were placed.
I also noted that the depth of the image could be shifted depending on how far the FEQ's were sitting in relation to the front plane of the speakers. For example, if I pushed the FEQ's along the back wall, as far behind the speakers as I could get, the soundstage shifted backwards which was very pleasing with classical music. Indeed well recorded classical music became sublime with the FEQ's in this position. In a somewhat freaky way, when I moved the FEQ's to sit in front of the speakers, they had a weird effect of pushing vocals more forward of the speaker - electronic and highly produced music really exaggerated this effect.
I did note that there was generally more upper frequency energy (but that might have just been the reduction in bass energy).
I did note that 1 unit sounded much better than 2 units. 2 units exaggerated the soundstage focus and depth effects whereas one unit gave a much more subtle result which enhanced recordings.
I also discovered through measurements (not shown) and subjective listening that raising the FEQ's off the floor tended to reduce the bass less and generally give a more subtle result that being placed on the floor.
Conclusion:
So I got a surprise from these results and the people who have been through my listening room have been quite intrigued by the tests that I've done. I don't think the sceptics will be in the least bit swayed by my findings. When the present graphs, they debunk them. When you do blind tests, they debunk those. And as for subjective tests and trusting your ears to collect data, give me a break!
Hope you enjoyed reading this.
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Post by Deleted on Nov 18, 2019 20:24:02 GMT 10
Hi Scumbag Where do you believe all of this spurious LF energy is coming from ? For example, would it be much lower in a Rural area, and perhaps much higher closer to a Motorway ? Regards Alex That low frequency energy is in all of my room measurements and is a function of the pretty savage bass modes in my room. It's my office so I can't do anything to treat it. It's almost a cube. It has plasterboard directly fixed to sandstone and double brick walls. Plasterboard ceiling and some carpet. Lots of hard reflective surfaces and no treatment. It's a poster boy for how not to build a listening room. See here - www.stereo.net.au/forums/topic/296346-avaa-active-base-trap/?tab=comments#comment-4417247 for a comparison although the measurements in the linked post are of the right speaker alone, not the stereo pair. |
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Post by Deleted on Nov 18, 2019 20:30:58 GMT 10
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sandyk (RIP Alex, 1939 - 2021)
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Posts: 226
About Me: Retired ex Principal Telecommunications Technical Officer with 43 years at Telstra (Australia)
I am also a Moderator in Hi Fi Critic Forum
Electronics hobbyist for >65 years with DIY projects including Loudspeakers, Stereo FM tuner, S/W Regen Receiver, Superhet AM ,
Synchrodyne PLL AM tuner (Phase Lock Loop),Stereo Tape Deck, Amplifiers including I.C. types, Class A, Class AB 100W/Ch. (ETI5000) 240W/Ch. Mosfet (AEM6000) ,several DACs , numerous PSUs including VERY low noise (<4uV) types etc.for myself and friends
Audio Industry Affiliation: NIL
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Post by sandyk (RIP Alex, 1939 - 2021) on Nov 18, 2019 20:39:39 GMT 10
I am unable to access that link as I was banned : "Sandy, I see that you do not want to needlessly disrupt, but we will find your type of contributions too hard to moderate on a general hi-fi forum"
David will be unavailable from today as he will be overseas for just over a month.
John Dyson may be able to discuss this with you though, if he is able to spare the time.
Regards
Alex
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Post by Deleted on Nov 18, 2019 20:55:58 GMT 10
I am unable to access that link as I was banned : "Sandy, I see that you do not want to needlessly disrupt, but we will find your type of contributions too hard to moderate on a general hi-fi forum" David will be unavailable from today as he will be overseas for just over a month. John Dyson may be able to discuss this with you though, if he is able to spare the time. Regards Alex I won't get a PM like that on SNA simply because I have pretty much stopped posting on there. |
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Post by Deleted on Nov 18, 2019 20:57:04 GMT 10
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sandyk (RIP Alex, 1939 - 2021)
Global Moderator
Posts: 226
About Me: Retired ex Principal Telecommunications Technical Officer with 43 years at Telstra (Australia)
I am also a Moderator in Hi Fi Critic Forum
Electronics hobbyist for >65 years with DIY projects including Loudspeakers, Stereo FM tuner, S/W Regen Receiver, Superhet AM ,
Synchrodyne PLL AM tuner (Phase Lock Loop),Stereo Tape Deck, Amplifiers including I.C. types, Class A, Class AB 100W/Ch. (ETI5000) 240W/Ch. Mosfet (AEM6000) ,several DACs , numerous PSUs including VERY low noise (<4uV) types etc.for myself and friends
Audio Industry Affiliation: NIL
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Post by sandyk (RIP Alex, 1939 - 2021) on Nov 20, 2019 8:24:59 GMT 10
Conclusion: So I got a surprise from these results and the people who have been through my listening room have been quite intrigued by the tests that I've done. I don't think the sceptics will be in the least bit swayed by my findings. When the present graphs, they debunk them. When you do blind tests, they debunk those. And as for subjective tests and trusting your ears to collect data, give me a break! Hope you enjoyed reading this. Hi Scumbag Sorry about the late reply. Interesting results, with confirming measurements too. In my case, I didn't feel the need to go to that trouble at a previous rented house in Sydney. I placed several 1M high x 2M long 50mm thick lengths of soft foam from Clark Rubber along both side walls and shorter lengths along the rear wall immediately behind both speakers. It had the added bonus of markedly reducing the noise through the thin walls that could annoy the neighbours . Due to only being a rented house I didn't bother to place them in more attractive covers, and the foam discoloured a bit.
Kind Regards Alex
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Post by frednorc on Nov 22, 2019 23:39:47 GMT 10
Pretty extraordinary results you have shown there @scumbag. Any ideas on whats going on? They say these output ultra low frequency RF pulses (like a Schumann resonator?) but perhaps at multiple frequencies.
The SR site seems to have a new improved version now which it says is 4 times the antennas so much stronger.
Which version is yours?
Made me look at their other gear. They actually have a specific Bass tuning unit which is around the size of a shoe box. Would be very interesting to measure that.
Thanks for posting your observations.
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Post by Deleted on Nov 23, 2019 11:13:45 GMT 10
I have no idea what's going on. Obviously since you can measure consistent changes in the overall response, particularly in the bass region, we are dealing with some sort of real mechanism here. I think it fair to trust the manufacturers explanation. Ultra low frequency RF pulses? Sure why not? I remember getting into an interesting conversation with a bloke on the bus coming home from the City when I was working at an Architectural firm in Brisbane. He was an engineer who had worked on radio communications research a few years early. He told me, in deliberately vague ways, about how they have discovered that you could transmit secure ultra high frequencies over huge distances. I asked a few exploratory questions but he wouldn't give me anything specifically. To my understanding, it sounded like he was suggesting that they were riding a UHF signal on top of a ULF signal but since he was at pains to not disclose the technology, he didn't clarify. Perhaps this is common knowledge now amongst engineers but at the time it was highly secretive. He seemed totally plausible to me - he had no reason to lie really, it wasn't like he has gaining any reputation points. But he hinted that this technology was (at the time at least) way outside of the conventional radio engineering textbook.
If the devices did nothing then we could easily dismiss their claims. I'm very glad that I can measure the results as otherwise I would be doubting the sanity of myself and the other people who have heard them in action. Obviously SR has some ideas about ways to manipulate the sound in a room with no electronic interaction. As you say, now that this evidence is available, it starts to make those of us with enquiring minds wonder if their other devices will work too. They do state that you shouldn't use a Schumann Generator with the FEQ's so there may be some degree of overlap in the frequencies that they emit.
The Bass box would presumably be using a similar mechanism to the FEQ but it would be tuned to affect the bass region more. Given the results within the bass region on would assume that a larger, specifically tuned device would have a larger effect.
I have the first version. I bought 2 of them because I wanted to experiment with positioning. I have found that 2 give, to me, an over the top effect in my very small listening space. They may course they might have made some adjustments to the X4 design since the first iteration. And of course, most people will be listening in spaces that are larger than my room so a X4 may be perfect for them.
I'm going to sell one of the units and keep the other one as I've decided, after a lot of fiddling and adjustment that 1 is enough for me at the moment.
Mark
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