Live 3 second delay / echo

[arawire]

OK... I'm not a sound person so may not have the correct terminology - what I want is to create a live 3 second echo - so If I say "blah blah blah" into a microphone ... there will be a 3 second delay and then the speakers with say "blah, blah, blah" ... Would anyone know what hardware / software would be needed for this - I would appreciate any help pointing me in the right direction. Thanks in advance

[Hugh Robjohns]

The device you need is a digital effects processor with a (single tap) delay program with at least a 3 second memory. Something like the TC electronic M-One XL, for example, which can provide up to 4 seconds in its delay effect.



https://www.soundonsound.com/reviews/tc ... ic-mone-xl

However, there are lots of effects processors around that can do the same thing. And these days most digital mixing desks incorporate similar effects programs and might be able to do the same thing internally.

So I guess the important next question is how to wire a device like this into your mic and speaker system, and to do that we'll need to know what equipment the rest of your set-up involves.

H

[CS70]

Yes, most desks nowadays have a built in delay so I’d check that first. However, many can run only one effect at a time, so if you want say both a vocal reverb and your effect delay, you may need a separate delay effect box.

[Moroccomoose]

Which ever solution you settle on (Hardware or software), the key important controls for the effect you describe are:

1: Delay length - obviously you will need 3+ seconds (Could be described as 3000ms)

2: Wet and dry mix control, so you can turn down the undelayed voice to zero and turn up the delayed effect to unity (The same volume as the input) - this could be two separate knobs one for dry volume (undelayed input) which you would turn down and one for wet volume which you would turn up. Alternatively, it could be one knob where all the way left is 100% dry signal and all the way right is 100% delayed signal and half way is 50.50, i.e. a bit of both. You would want it turned to 100% wet.

3:Feedback control that will turn down to zero so you only get one instance of the original voice repeated (Not a decaying wash of several repeated delays - which is a bit like a reverb)

As Hugh says, depending on your set will dictate how you end up hooking the effect into your rig.

Stu.

[arawire]

Thanks for the great replies.... yes it makes sense that the device has some sort of memory to record the 3 seconds before playing back.

I have absolutely no equipment. This is a new set up for an artwork - I just wanted the effect that there was a " Wall" and it just repeated with a 3 sec delay, what the people next to the wall were saying. It would be left on for weeks.

So I envisage it will take a Mic, Speakers and as recommended a digital effects processor - would that constitute a set-up or is something else needed ?

This has been really helpful. Thanks!

[Hugh Robjohns]

Ah... okay. Thanks for that -- it gives a much better idea of what you need.

Is there a budget for this? Will you be buying equipment for it specifically, or perhaps hiring for the duration (which might be more cost effective)?

I suspect a mic preamp, an FX processor, and some powered speakers will be the best way to achieve what you're trying to do.

But as this is clearly in the live-sound arena I'll move the thread to the Live sound forum where you'll get more relevant answers.

[arawire]

Lowish budget - around £500 (well that's high for the artworld!) ...
I looked up Mic Preamp - and makes sense to use one.
Is there a difference between speakers and "powered" speakers?

Yes .. makes sense now that it's in the live forum.

Thanks again

[Mike Stranks]

There's always the Behringer FBQ100 ( https://www.behringer.com/Categories/Behringer/Signal-Processors/Feedback-Suppressors/FBQ100/p/P0A3Q#googtrans(en|en)

to which you could connect a mic and powered speakers, BUT it will only give you 2.5 seconds max delay.

How critical is the 3 seconds? What's half-a-second between friends?

[AlecSp]

The Behringer XR16 mixer will do a 3,000 ms delay, and will also do the mic pre-amp & mixing thing. Just add a powered speaker or two and a mic.

Then, if you've no experience in audio, be prepared to be disappointed when the microphone will only pick up sounds very close to it, and/or you can't get the repeats coming out as loud as you'd hoped. There are laws of physics that you're likely to come up against.

[FrankF]

Plenty of recommendations in this thread, mostly guitar-type pedals, and a lot longer than 3 seconds in some cases, but at least you're spoilt for choice. Also, you might save some budget cash if you buy 2nd hand (several of these are no longer made).

https://www.soundonsound.com/forum/view ... se#p614614

[Stratman57]

Is the wall going to freestanding so that the speakers and preamp/delay unit can be placed behind? As a wall is part of the installation I'd use a PZM (pressure zone microphone) also called a boundary mic. This could be mounted on the surface of the wall at a convenient height to maximise voice pickup.

Regards, Simon.

[The Elf]

The warning about preparation for disappointment is worthy of repetition.

Getting a mic to pick up at distance (even a very sensitive mic), and giving the delay sufficient gain to be audible without feeding back horribly, are going to give you headaches you can't even begin to imagine right now.

If you can find an audio pro to help, please do it ASAP. I feel you could avoid a lot of heartache.

[Arpangel]

How about a Boss DD7 connected to a cheap Behringer mixer send and return? Or, even cheaper, one of the many delay apps for your phone or tablet? like Aux FX Dub? Just download AudioBus and it'll suggest loads of delays via its compatible apps.

[Mike Stranks]

So far I've just concentrated on technical solutions...

Others have rightly homed-in on mic and speaker placement issues...

and another thing...

I visited a local sculpture exhibition several times earlier in the summer to shoot some video... Most of the exhibits were in the open-air, but there was one in a shed where different lights illuminated according to volume and frequency combinations as people spoke/shouted/made noises. Great fun - for me. But not a great success as people were keen to go in there, but as soon as they realised what it was they were immediately struck dumb and walked out again. Reticence/reserve/low-profile/self-consciousness etc were the order of the day. That's the English middle classes for you!

[Wonks]

This covers a lot of the same ground as was discussed in this thread, earlier in the year:

https://www.soundonsound.com/forum/view ... on#p537764

[MarkPAman]

The Behringer XR12 will do the preamp & delay bit for just over £200 (and can be sold afterwards) - that's the easy bit. Choice of mic (or maybe mics?), and its position relative to the speaker(s) will be much more tricky.

[Sam Spoons]

Maybe a case for a shotgun mic?

[Mike Stranks]

Maybe a case for a shotgun mic?

Probably not; indoors, because of wall reflections, they can often cause more problems than they solve. If it's not a PZM then a hypercardioid might work... but it'll always be tricky if the mic to speaker distance is more than a foot or so - especially in a small space.

[Sam Spoons]

I was thinking of focusing on a small area in front of the wall a bit like spotting a particular point on the stage from above in a stage show to capture a bit of dialogue but have not tried it myself so will, happily, bow to Mike's greater experience.

[Stratman57]

OK, I've given this a quick try and it seems that it could work.

I used a Tandy (remember them?) PZM connected to my XR18, set up with a 3s delay, no dry signal and palyedback via my Rockit 5 monitors. (see screen grab for mixer settings).



Holding the mic about 30cm in front of the speakers I managed to get a feedback free repeat after 3s. Mounting the mic on a wall with the speakers at each end of the wall should work much better, especially if the installation is in a largish gallery space.

Regards, Simon.

[Sam Spoons]

Good effort Stratman, I was wondering myself how much delay is required to make the system impervious to feedback, or indeed if that's possible. I did try short delays (a few ms) a few years ago but they did not help much if at all. I guess if the delay is less than the room's reverb time feedback/howlround will be a risk.

[Folderol]

A suggestion (from the depth of my ignorance)
Mount mic and speakers on the same surface pointing to a highly sound absorbent one the other side of the room/corridor or whatever. Apply a fairly narrow band-pass filter to the microphone - just wide enough to respond reasonably to speech.

[Stratman57]

Thanks Sam.

I was working on the theory that the surface the PZM is mounted on effectively disappears, so if the mic was mounted on a large wall with the speakers maybe flush with the wall surface the feedback would be minimised, assuming the mic was isolated from wall vibrations. I had the repeat level less than the mic level, so the next 3s repeat wouldn't start to feedback.

I only had a low cut filter on the mic, but having a high cut would also help I think. The PZM I was using was as standard, not modified to use phantom power or for balanced operation so I think with a higher spec boundary mic more gain before feedback could be achieved. The hemispherical pick up pattern could also be modified to minimise pickup from the speakers.

Interesting problem, it's the sort of thing the drama director I work with would come up with for a production, and expect me to sort it out. And fun to do without the pressure.

Regards, Simon.

[Hugh Robjohns]

...if the mic was mounted on a large wall with the speakers maybe flush with the wall surface the feedback would be minimised, assuming the mic was isolated from wall vibrations.

A PZM on the wall with soffit-mounted speakers would be a sensible solution, but it would need an effective high-pass filter to prevent pickup of the LF from the speakers which would radiate hemispherically along the wall.

The mid and HF from the speakers normally has a much narrower radiation patter so the PZM in the middle of the wall would, effectively, be in a sound shadow and not pick up much direct sound at all. Strong reflections from any rear or side walls would be the biggest problem, but drapes or similar would deal with the worst of that...

H