hughes srs ak100/stereo enhancers

[Rodgre]

Hello all.

From time to time, I look around for info on the Bedini B.A.S.E. and Hughes SRS AK-100 stereo enhancers and I find little about them. I was wondering if anyone really knew the technical story about them and the circuit topology. I'm familiar with the Haas effect with short delays and I'm familiar with the adding R to L and subtracting L from R stereo spreaders of things like the Behringer Edison and Waves Imager plugin. The B.A.S.E. and Hughes seem to do something different and from what I've gathered, pretty guarded and secret. Therefore it must be something super simple, right? Ha! I'm hoping it's a ten-component circuit just covered in half a pound of epoxy goop.

So does anyone really know what they are technically doing? Has anyone made a plugin that does a similar thing? I do use Waves S1 and Stereo Maker to manipulate things a little, but when it comes to making things sound like they're beyond the speakers, I've not found something that does what I want.

ASIDE: what got me interested in becoming an engineer as well as obsessed with guitar effects as a kid was one particular moment on a Rush album. At exactly 9:31 in this video https://youtu.be/zfloBf5yLi8 of "Cygnus X-1 Book 2 Hemispheres" by Rush, there is a lead guitar part with chorus and flanging on it that seems to circle your head in headphones. It completely blew my mind as a 10 year old. It's a dragon I've been chasing ever since. I realize that this effect is more to do with short delays and the combined chorus and flanging effects, but the concept of sound swirling around your head in stereo, not just a panning mono source, has been an obsession ever since.

Roger

[Nick Sevilla]

That guitar part starts at 9:29, and it sounds like just someone panning the melody guitar about.

I really cannot hear weirdness of the chorus too much, I do hear the flanging, which is what makes the guitar sounds like it is going a little behind your head. It is a psychoacoustic effect. Cool effect.

[Rodgre]

That guitar part starts at 9:29, and it sounds like just someone panning the melody guitar about.

I really cannot hear weirdness of the chorus too much, I do hear the flanging, which is what makes the guitar sounds like it is going a little behind your head. It is a psychoacoustic effect. Cool effect.

If you listen in headphones, it's definitely a dramatic effect. To my ears, its not a mono source with effects sent from an aux, with the mono source panned from side to side. To my ears, and this could be due to the psychoacoustic effect of the flanging, it sounds like it starts out in stereo, with a chorus effect to make it that way, so it's left and right. Then as the riff plays, it moves FURTHER left and right, not side to side, but just wider. It's possible that there is a delay on one side which just gets panned harder as the riff plays, to make it seem wider. The vocal part immediately after this section in the song has a tight slap delay on it which is mono at first and at the end of the section pans the dry to one side and the wet to the other (to dramatically illustrate the two "hemispheres" that the lyric is describing). I think I need to get a hold of Terry Brown and ask him.

Roger

[Nick Sevilla]

If you listen in headphones, it's definitely a dramatic effect. To my ears, its not a mono source with effects sent from an aux, with the mono source panned from side to side. To my ears, and this could be due to the psychoacoustic effect of the flanging, it sounds like it starts out in stereo, with a chorus effect to make it that way, so it's left and right. Then as the riff plays, it moves FURTHER left and right, not side to side, but just wider. It's possible that there is a delay on one side which just gets panned harder as the riff plays, to make it seem wider. The vocal part immediately after this section in the song has a tight slap delay on it which is mono at first and at the end of the section pans the dry to one side and the wet to the other (to dramatically illustrate the two "hemispheres" that the lyric is describing). I think I need to get a hold of Terry Brown and ask him.

Roger

I am listening on headphones.

The effect you describe could be that they set up a mono send to a Stereo chorus, which although softer, still fills the left right, as they panned the guitar around. If the send did not follow the panning, as many older consoles did not have this feature, it would explain why, although you hear the guitar being panned, you still hear the Stereo chorus effect almost the same on both channels. It is definitely a cool idea. Must try soon. They also could have had a delay on that send with the chorus.

Time to experiment in the studio, try to get close to what they did. Cheers!

And yes, get in touch with Terry, I hope he remembers what they did here.

[Colorblind]

Hello all.

From time to time, I look around for info on the Bedini B.A.S.E. and Hughes SRS AK-100 stereo enhancers and I find little about them. I was wondering if anyone really knew the technical story about them and the circuit topology. I'm familiar with the Haas effect with short delays and I'm familiar with the adding R to L and subtracting L from R stereo spreaders of things like the Behringer Edison and Waves Imager plugin. The B.A.S.E. and Hughes seem to do something different and from what I've gathered, pretty guarded and secret. Therefore it must be something super simple, right? Ha! I'm hoping it's a ten-component circuit just covered in half a pound of epoxy goop.

So does anyone really know what they are technically doing? Has anyone made a plugin that does a similar thing? I do use Waves S1 and Stereo Maker to manipulate things a little, but when it comes to making things sound like they're beyond the speakers, I've not found something that does what I want.

ASIDE: what got me interested in becoming an engineer as well as obsessed with guitar effects as a kid was one particular moment on a Rush album. At exactly 9:31 in this video https://youtu.be/zfloBf5yLi8 of "Cygnus X-1 Book 2 Hemispheres" by Rush, there is a lead guitar part with chorus and flanging on it that seems to circle your head in headphones. It completely blew my mind as a 10 year old. It's a dragon I've been chasing ever since. I realize that this effect is more to do with short delays and the combined chorus and flanging effects, but the concept of sound swirling around your head in stereo, not just a panning mono source, has been an obsession ever since.

Roger

Is it possible they used a binaural mic technique for that guitar part? There are YouTube videos showing how to make a binaural mic on the cheap. That may not be what's happening here, but when I think of sound moving around behind the listener's head, I think of binaural recording.

[The Scum]

Is this the original SRS patent: https://patents.google.com/patent/US5251260A/en?

I know Kurzweil licensed SRS for KDFX/KSP8 in ~1997, so it had to exist then. That one also added reverb, so block 68 in the diagrams makes sense. Maybe it's just the "front SRS" portion of that? Checking quickly, there's no notice of patent licensing in the K2600 manual.

This looks similar: https://patents.google.com/patent/US8472631B2, click on the author, and there are a bunch of similar patents, all assigned to Hughes/SRS.

All of that is 15-20 years past Hemishpheres, though.

[The Scum]

Or perhaps this one: https://patentimages.storage.googleapis ... 866774.pdf

[Rodgre]

So some research has led me to believe that the Bedini BASE was essentially cloned in the Behringer Edison, which led me to realize that it's very similar to the Electronic Musician magazine Stereo Spreader I built in 1991.

https://paia.com/manuals/docs/9140_200.pdf

Probably one of the simplest circuits this side of a Fuzz Face. People have paid so many thousands for BASE units and it's literally $8 of parts.

This is also exactly how the Wave S1 Imager plugin works, so I have that covered. The Waves Shuffler does some cool stereo creation, beyond just manipulation so that's more useful to me than just the Imager alone.

Now to peruse the Hughes SRS patents and see where that's at. I am starting to feel like these devices were very simple and had a good deal of obfuscation in their builds that made it seem like more was going on than actually was.

Roger

[Magnetic Services]

the concept of sound swirling around your head in stereo, not just a panning mono source, has been an obsession ever since.

You need to get into Ambisonics!

[winky dinglehoffer]

So some research has led me to believe that the Bedini BASE was essentially cloned in the Behringer Edison, which led me to realize that it's very similar to the Electronic Musician magazine Stereo Spreader I built in 1991.

https://paia.com/manuals/docs/9140_200.pdf

Orban's stereo synthesizer would appear (If I'm understanding properly) to be a fancier version of the same idea--a few more bells & whistles in the circuitry though. Schematics and circuit description in the manual:
ftp://ftp.orban.com/245/245F_Manual.pdf

[The Scum]

The Orban's not that much more...7 opamps?

A static phase shifter, and an M-S decoder. Phase shifted signal becomes the S channel, dry signal is M.

(kinda reminds me of the mono-stereo trick with a stereo graphic EQ - run mono input to both channels, boost even-numbered bands on one side, odd numbered bands on the other.)

[eggCota]

I have used the Bedini BASE and the Behringer Edison side by side and I can confirm that the layout of the buttons and the effects on the signal on/w the Edison is classic Behringer's attempt at copying the BASE. The Bedini sounds much richer and retains more low end information and definitely has transformer coupled either ins or outs or both. I would assume they use higher quality opamps as well.

More recently, I modded my Edison with Nichicon caps in the audio path, Panasonic in the power supply section, and added Behringer OT-1 Transformers and I can say that though I can't compare it directly to a Bedini, I wouldn't be far off to say that the modded Edison is now within a few percentage points of sounding just as large, open, and rich as the BASE.

As to how it works? I believe the patent shown above is likely right on point. There's some form of spectral band Hass effect going on, but that I can not verify. The inside of an Edison is quite simple in design though.

[Rodgre]

More recently, I modded my Edison...

That's pretty cool that you did that. Very smart idea.

I'm going to hazard a guess that the Behringer doesn't have a delay or phase shift circuit to do a true Haas effect, but, like the Electronic Musician article I linked to above, is just inverting phase and blending the inverted signal with the opposite channel, essentially pulling the MID signal back and pushing the SIDES up (or vice-versa if you're trying to close up the stereo field a bit). This is what the Waves S1 Imager plugin does as well, with a bit more control over "rotation" of the signal.

I guess i DO need to get into Ambisonics!

Fascinating stuff...

Roger

[cgarges]

Just an aside, if anyone wants to buy an Edison or an Orban Stereo Synthesizer, let me know.

Chris Garges
Charlotte, NC