Making an effect stereo?

[jimosity]

Whats the logic in making an effect stereo if its not naturally a stereo effect?
Or what else is required to give it a stereo separation?

[petemoore]

"Dual Mono'' is the 'other stereo' phrase, differences between left and right channels>amps>speakers may qualify as 'stereo', it depends on the definition.

[jimosity]

So, dual mono would be the same as adding another input that's going into the circuit and a second output jack that's also coming from the same circuit output?    That'd be exactly the same thing coming out of the unit though, right?  Just giving you another jack to plug in if needed on the following unit?

[Taylor]

What specific effect are you talking about?
What are you doing with it?
What are you trying to get out of making it stereo?

This question is too open-ended without more info.

[jimosity]

A cabinet simulator is specifically what I'm asking about.
If I want to make it a 'stereo' cab sim, is there anything I can do to give it more separation so that both channels don't sound 100% the same, but don't cancel each other out?.

[artifus]

send it a stereo signal.

*edit* apologies for previous short response, was just passing thru on my way to somewhere else. if creating a stereo effect from a mono source with studio trickery (delay, etc) be sure to check for mono compatibility and phase discrepancies by monitoring in mono (summing the two signals) occasionally.

Phase Demystified

Stereo Lab

[aron]

You can slightly delay one channel vs the other. Slight chorus is another trick. You can split the frequency bands and send only certain frequencies to a channel. All easy in the digital domain!

[Brymus]

You can slightly delay one channel vs the other. Slight chorus is another trick. You can split the frequency bands and send only certain frequencies to a channel. All easy in the digital domain!

The first couple of DAWs I used didnt have stereo in ,on one track .
When I recorded guitar or bass,ect I would copy it to two tracks,and do like Aron said.
Just EQ each track differently and add a hint of delay to one.

[Processaurus]

Some designers of modulation pedals that have stereo outs (phasers, flangers, chorus come to mind) will employ a Mid/Side type thing, where you have the dry going identically to both channels, but the wet, before it is mixed with the dry, has its phase reversed on one of the channels, which can sound very wide and nice.

[jimosity]

send it a stereo signal.

*edit* apologies for previous short response, was just passing thru on my way to somewhere else. if creating a stereo effect from a mono source with studio trickery (delay, etc) be sure to check for mono compatibility and phase discrepancies by monitoring in mono (summing the two signals) occasionally.

Phase Demystified

Stereo Lab

In the "Phase Demystified", I see this statement: "They use a phase-shifting circuit, which enables the user basically to decide which frequencies add constructively and which still cancel — allowing the subjective 'focus' of a sound to be optimised, or the sound quality from the combination of DI and miked signals to be tweaked in a satisfying way."

Do you have any suggestions for a simple phase shifting circuit?

[artifus]

i'm afraid not. i would be very interested to see what is going on inside the little labs ibp box. i've only used software.

*edit* such as phase bug freeware. link via http://www.cambridge-mt.com/ms-links.htm#freeware

*edit*edit* just found this: ibp manual pdf which has a few clues. block diagram, no schem. i'm sure someone more knowledgeable than myself will chime in. *hopes*

*edit*edit*edit* (last one, promise) not read thru yet but maybe here: prodigy pro discussion

[jimosity]

Hmm.

http://www.gearwire.com/smaudio-pcontrol-wnamm09.html
This looks promising as well.

[Mark Hammer]

In the 70's (and even up to the 80's), there were still plenty of mono signal sources in recorded material in wide circulation, but an expectation that stereo listening was preferred.  As a result, we saw a number of commercial devices aimed at synthesizing mono from stereo.

Among the most common were what might be called "interleaved comb filters".  A mono signal went through two parallel phase-shift networks that produced notches at different interpolated frequencies.  So, channel 1 would produce notches at frequencies A, B, C and D, and channel 2 would have notches in between A and B, between B and C, and so on.  The two derived channels were the same content, more or less, but had enough differences in their frequency content to sound different.

This was used in vinyl discs that were "electronically enhanced for stereo", but was also available in IC form and magazine project form for those who wanted to do the "electronic enhancement" themselves.

It is probably a simpler affair to use a 3207/3102 chipset, and sum/subtract the wet signal with dry, to produce a bunch of notches.  Unfortunately, to get the sort of delay time that introduces notches low enough in the frequency spectrum to have an impact on perceived channel to channel differences, you would need to introduce a fair amount of delay (e.g., 8-10msec), which then creates issues of managing clock noise, and a sense of room resonances.  Moreover, the resulting outputs cancel "in air" when the peaks on one side meet the dips on the other.  Use of deliberately engineered notches poses less issue with clock noise (no clock) and allows you to situate notches that do not cancel in air.

[vendettav]

hmm what got to my mind the first was... if you are willing to have two mono signals pass thru the unit than you'll need more or less 2 schematics of the same thing. imagine stereo amplifier with stereo input. *shrug*

[Scruffie]

http://www.effectsdatabase.com/model/eh/ambitron

[Mark Hammer]

http://www.effectsdatabase.com/model/eh/ambitron

A perfect example of what I was talking about, using a BBD. 

If I remember correctly, both Philips and National Semiconductor produced 14-pin dips that did the staggered-notch thing.  I'm blocking on the part numbers for them.  Pretty sure I have some project articles at home from ETI that use one or the other.  Like I say, it was a pretty common thing in the 70's.

[artifus]

i have an old hifi tandy 'realistic stereo reverb system' box that does exactly that. it's bbd based i believe but i've yet to open it up. kinda karaoke before karaoke. it has a mic input that destroys electric guitar signals quite beautifully. i worked in a studio some time ago that had an older pioneer hifi unit that sounded similar. quite a quirky, character sound. definitely occasionally useful. but due to the mono cancellation was only really ever used as spot fx on occasional parts - solo's, samples, sound effects, dialogue etc.

the vibe i got from the op was that they were asking about a stereo cab and how to make it sound more 'stereo' to which the obvious answer, at least to the bleary eyed, pre coffee me at the time was that the op should send that stereo cab a stereo signal. maybe move the speakers further apart. what is meant by more stereo? studio or live? headphones? and if that be from a mono source, ie guitar, then we need to actually create some stereo effect from that mono source to send to the stereo cab. when people say stereo i often imagine them thinking of crazy panning, ping pong delays, swooshy flangers, chorus or phaser fx, huge reverbs, you know, the obvious stuff. or are they being more subtle, are they just after a bigger dry sound? (which could also be created with, ironically enough, stereo delay fx) again, live or studio and what is actually achievable in each scenario? so what is the op looking for? stereo is a fascinating subject but also a rather large and perhaps vague one rather like fuzz. sorry i'm rambling. time for bed.

[EATyourGuitar]

your playing with fire if you dont fully understand the problems engineers face when trying to make a recording good for mono AND good for stereo. definitely read up on mid/side recording techniques as well as how they are mixed using special tricks. you also have to understand how the L+R signals from the side mic (figure 8 patern mic 90 degrees to the source) cancel each other when they get summed in the final listening device if its mono. there are shit loads of things you can do to a mono signal to get it to sound stereo. the problem is that when you record you have to be considerate of what garbage might come out when its summed mono. if you dont want to get your signal all phased and chorused and reverb and delayed, you start looking at inverted complementary comb filters as mentioned above. it gives the illusion of two different speakers or a room that is asymmetrical (or rather a room that reflects and absorbs sound differently on either side of your head and may or may not be a geometrically symmetrical room in the first place ). I would consult an engineer before you settle on the final design.