OK – Gain, in the context of a highly transparent audio system. To some, the following will seem like long-winded nit picking. If you’re perfectly happy with the sound that you’re producing with your systems, no matter how you’re getting it, then by all means don’t fix what ain’t broken. To others, it may be perceived as overly simplified. Please know that I’m not trying to ‘dumb it down’. I offer this attempt at explaining how audio systems work, in the most non-technical language that I can muster, to anyone who wishes to learn how to coax the absolute best possible results from their audio system. Your critique, the measure of my success/failure, is welcome and appreciated…

Let’s begin at The Source.

Imagine a tiny wave riding down a wire at the speed of light. We know what caused the wave and that it was beautiful. We want to somehow use the tiny wave to move the air around us with sufficient energy and uniformity so that everyone in the space can hear that beautiful source clearly. When we hear the sound clearly, we may smile and leave it alone, or wince and choose to modify some of its traits, but ideally, any gizmos that we use along the way shouldn't impose unwanted changes...

Some examples of simple sources:

  • Voice > mic > wire >
  • Instrument > wire >
  • Instrument > mic/pickup > wire >
  • Instrument > pickup > wire > mic'd amp > wire >
  • Recorded sound > recorded sound player > wire >

    Some examples of sources which are more complex:

  • Voice > mic > wire > effects/mixer > wire >
  • Instrument > mic and/or pickup > wire > effects/mixer > wire >
  • Recorded sound > recorded sound player > wire > effects/mixer > wire >


    The Gizmos.

    For the past several decades, we humans have strived to make our beautiful sources louder and clearer with the goesintas, comesoutas, amps and speakers of (cue announcer voice) THE SOUND SYSTEM. The mere mention of it strikes fear into the hearts of many, but it can really be quite friendly and effective if we understand how to make a few sensible adjustments to help it perform at its best. To those of us wanting only to produce and control what is heard by us and our audiences, these gizmos are nothing more or less than a series of controlled steps toward making our wave bigger. These steps are commonly referred to as gain stages by tech-head geeks like me. Let's look at the path that our tiny wave follows through an audio system:

  • Source – Our tiny wave. Its output connects to a gizmo with knobs and meters on it...
  • Trim – First stage of the gizmo. Makes the tiny wave bigger, just the right size for the gizmo to do its best work...
  • Level – Second stage of the gizmo. Brings the now bigger wave into balance with others that are sharing the gizmo and to where their mix creates a level that makes the next stage happy...
  • Master – Combines all of these bigger waves and sends them to the next stage at a level that makes it happy...
  • Power Amp – A last big boost, by far the biggest of all, so big that it can make a loudspeaker wiggle, a lot...
  • Loudspeaker – Makes air wiggle, a little or a lot...
  • Wiggling Air – Makes people wiggle. (Whole 'nother subject. Back to gain...)


    For the simple sources above, we simply plug into an input channel of our favorite gizmo, hit it as hard as we're gonna and then adjust that channel's controls, step by step - first Trim, then Level - for the desired result, optimum performance. Repeat for each additional source. Then we bring up the Master volume control to the desired listening level. Now that we can hear the individual sources clearly, we can modify their tone with EQ, their mix (relative balance) with Level controls and the overall loudness of that mix with the Master, to suit our tastes and needs. Done.

    The more complex sources above bring lots of their own gain stages to the party. Our ears hope that we've set them all correctly before we plug them into something that will let us hear them. Failure to optimize each and every one of them can and usually does result in unwanted changes to the source (e.g. hiss, insufficient level, distortion, feedback) which our L1s will very faithfully reproduce as wiggling air. For example, if we run the Master of an external sub mixer well below its output capacity, we're sending a mix that has higher hiss content than necessary to the next stage, the PS1 Input. We end up boosting that next stage to compensate, which boosts the signal, yes, but it also boosts the hiss by the same amount. Hiss is bad. It is unwanted noise. Some noise is inevitable in any gizmo, but since it is part of the sound to which we are critically listening, we want to minimize it wherever possible. We’re going for what tech-head geeks like me call ‘the highest possible signal-to-noise ratio'…

    When wiggling air with our beloved half-cylinders, I propose that we'll always get the best possible sound quality when we set each and every stage of an external sub mixer, input through output, for optimum performance (as much signal as possible, but not too much) before connecting it to a PS1 input. Then we optimize the PS1 Input's trim control. Then level. Last of all, we adjust the overall system volume with the Master on the R1...

    Notice that when we fire up a system without an R1 Remote connected, we hear noticeable hiss, even with nothing else connected to the system. This is because we’re running the system as if the Master was set to the 12:00 position, way higher than it needs to be for silence, or even for lower listening levels. With no R1 and sources connected and producing sound, we find the hiss to be noticeable only during silent passages and at lower listening levels. At louder listening levels, the signal has gone up while the hiss has stayed the same, so the hiss gets covered up, or masked by the louder signal. The best and only way to minimize/eliminate the hiss during silence or lower listening levels is to optimize every stage before the R1 Master and then use the R1 Master to achieve the desired listening level. Using the system without the R1 means that we’re stuck with any hiss that the system produces when that last stage stays set so high. It can also mean that we’re not allowing access to all of the available volume, since 12:00 is only half-way up the dial. If we’re always listening at a louder volume levels, never distracted by hiss and we don’t ever find ourselves wishing that we had a tad more volume, then we may certainly forgo the R1 Remote…

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Original Post
Well Chuck, it's pretty quiet here, not sure what that means but let me say I appreciate your effort, but honestly, if the true tech jargon is misunderstood by the non techies, then I'm not sure this will help either.

We should try as a group to make the proper terms more easily understood. Maybe that would make a good topic for those who gather at Big Sur.

I could't help but notice you did the whole piece without using the word "maximum" at all, that was quite a feat in itself and I applaud you for it. I think, and I may be the only one, but I think we confuse the gain issue when we use terms such as "maximum" in relation to signal strength.

I have assisted persons using a mixer and found the mixer channel gain turned up to the maximum. This results in every other following stage not being set to proper levels for best overall performance.

How to explain the difference between maximum as in, all the way up, and, maximum as in, the best signal to noise ratio, in a way that non techies can absorb, understand, and make it work, is an obstacle we, as a group, have not overcome, though you have made a gallant step in that direction.

It may be just me, and if you think it is please tell me so, but I think the Bose Personalized Amplification System is the most critical system I have ever used when it comes to proper gain staging. Maybe because we hear the finished product better we become more critical as listeners, but that is a good thing. Right? So we have to become better sound engineers.

The difference between not enough gain and just right, is like night and day. It affects the tonal balance of the system, and when done right you won't hear a customer saying, It's thin, or tinney, or am radio sounding.

There is a piece written by Ken-at-Bose about proper gain setting for vocal mics when one needs maximum gain before feedback. Again this is just my opinion but, I think sometimes people having trouble are referred to this statement and try to follow it when they don't really need maximum gain before feedback. What they need is a better understanding of close mic technique, and a way to get the best possible setting for their vocal style. It's not that Ken's information is wrong, but it is misunderstood and misapplied, in my opinion. An example of misapplied would be when one user followed those instructions in an attempt to solve a feedback problem while micing acoustic instruments.

Most singers have a natural tendency to get on the mic when singing softly and backing off when singing loud. If I set the gain with my lips touching the mic and singing the loudest song I intend to do in my program, then there is a very good chance that setting will be too low to get a good response for all my other tunes that I sing in a softer more natural way.

In my experience mics that have a pronounced proximity effect (SM 58 is one example) are even harder to work with if the gain is set in the manner described by Ken.

Please understand, I am not saying that Ken's info is wrong, I am saying that I think it is not always used in the same context as it was intended.

These are two issues, setting gain when using outboard mixers, and vocal mic settings for all occasions, that I think are the most misunderstood and cause many of the less than desirable, first PAS impressions.

Can we get some more input here that will result in more uniformity and easier to follow directions for our tech challenged friends and new users?

This system is not that difficult for those who have experience with other equipment but I remember having difficulty with gain in my first weeks of use, and I came to it with 40 years of prior "sound system" use. The Bose Personalized Amplification System is so appealling to first time buyers, and other inexperienced users, we need to make sure their first experience is a good one.

Oldghm
Hi Oldghm

Our Bose Systems are 'closed' integrated systems in the sense that they have been designed end-to-end based on known data.

That is, from some known inputs (listed in the presets), input trims, preamps, gain control through several stages internally, tone controls and presets through to power stages and unique characteristics of the Cylindrical Radiator®

Just as some instruments offer optimal results when used in certain ways, our Bose Systems work best when used as designed. For example: When reading about different kinds of Acoustic Guitars, I often encounter suggestions that dreadnaughts are better for some kind techniques whereas parlor style Guitars work best for others. I find similar recommended usage scenarios with microphones.

My point is that we have to learn to use the System, and for some this means setting aside some prior learning. It also means that some techniques that work well for the Bose Systems may not be universally applicable.

Cliff-at-Bose has said of the presets
"Here's a general comment on the presets: They were all developed to make CLOSE VOCALS (as in eat-the-mic) sound more natural through our system. When you back way off, say 6 inches or more, all bets are off. The same goes for even close miking of musical instruments. Actually, close miking of a Dobro might be fine in the flat setting, maybe turn up the HF on the remote for some sparkle. In the studio, a B57 sounds pretty useful 4-6 inches away from a guitar. Stay away from the sound hole if the sound gets too dark. Too much signal from the sound hole will also encourage low-mid feedback...." See it in context

When Ken or Steve (at-Bose) describe setting the gain using close-micing techniques, it seems to fit with the way the System was designed to be used. Or, it could be that Cliff designed the presets based on the assumption that the Vocalist would be following this style of mic technique. Either way, these two critical factors (gain staging and mic technique) are inextricably related.

That doesn't mean that there is anything wrong doing things another way. It is not surprising to me if people get different results when using the System in other ways.

As soon as you introduce external gear like mixers, preamps and effects, you may well find that different techniques are more appropriate.

Working with naive performers a lot, I find that close-micing and setting the trims as recommended provides consistent, predictable, repeatable results, typically without feedback or mic bleed when there are several performers and sound sources on stage. This is in fairly narrowly defined circumstances (live performance, in an ensemble, for live music). On the rare occasions when I perform solo I can take considerable liberties with the recommended techniques, but generally don't find it necessary.

For different applications like recording under controlled circumstances, I use different mics, different mic techniques, use mics instead of instrument pickups and a host of other differences that just would not work on a live stage.

I laud the efforts form the folks-at-Bose when they try to help us in our hybrid approaches. I also think it is important that we understand the context of all recommendations.

When used as designed...

When used in other ways...
Hi Oldghm,

Just a little more.

quote:
It may be just me, and if you think it is please tell me so, but I think the Bose Personalized Amplification System is the most critical system I have ever used when it comes to proper gain staging. Maybe because we hear the finished product better we become more critical as listeners, but that is a good thing. Right? So we have to become better sound engineers.

The difference between not enough gain and just right, is like night and day. It affects the tonal balance of the system, and when done right you won't hear a customer saying, It's thin, or tinney, or am radio sounding.



Feedback and Distortion

I've actually found the Bose System to be more forgiving than other things I have used in terms of feedback and distortion.

BUT

I'm guessing that (you and) I have become far more critical about what is acceptable now that we can actually hear what is happening. The absence of problems is something we take for granted. It's no longer the baseline.

There are times where I listen to what is happening (people playing through my Systems) and think, if the someone would just (fill in the dots) ... it could be better.

But when I step back from that, I can also appreciate that what is happening is so much better than the alternative. I look around and see people enjoying the music or just enjoying being there. I'm not settling for less than perfect. I'm accepting that what is happening is working. Maybe that *is* perfect.
Hi Oldghm,

Thanks so much for reading and commenting on my attempt...
quote:
...if the true tech jargon is misunderstood by the non techies, then I'm not sure this will help either.
When I checked recently and saw that it had been viewed 100 times without a single reply, I leaned toward the same conclusion...
quote:
The difference between not enough gain and just right, is like night and day. It affects the tonal balance of the system, and when done right you won't hear a customer saying, It's thin, or tinney, or am radio sounding.
I wholeheartedly agree, though I have found that to be true with all audio systems. That everyone in the room hears the L1 so uniformly makes it all the more critical to get it dialed in correctly...
quote:
Can we get some more input here that will result in more uniformity and easier to follow directions for our tech challenged friends and new users?
I'll second that request. Meanwhile, I'll continue revising my original post offline, in an effort to make it simpler and more easily understood...
Hi ST,

Thanks for your input above. I'm particularly grateful for
quote:
I'm guessing that (you and) I have become far more critical about what is acceptable now that we can actually hear what is happening. The absence of problems is something we take for granted. It's no longer the baseline.
quote:
Originally posted by ST:

Working with naive performers a lot, I find that close-micing and setting the trims as recommended provides consistent, predictable, repeatable results, typically without feedback or mic bleed when there are several performers and sound sources on stage.



I wholeheartedly agree, unfortunately, we cannot be at every new users first use, and based on the number of times we have tried to explain gain staging, and the number of folks who post concerns that experienced users think is gain related, I do believe we must do better.

I would go one step further than ST's comment and say that I don't even do individual checks anymore for performers. I have learned that there is a range of about 3db or so that works very well with my EV mics, I can adjust on the fly based on vocal style and strength

ST also said, "gain staging and mic technique are inextricably related". I would add that the mic one selects is also related, and all are subject to performance style. With practice, patience, and a little understanding the PAS will accommodate a wide range of performers with equally good results.

Maybe a glossary of applicable terms would help.

It is important to remember that what is perfectly clear and easy to understand to some of us is murky as swamp water to others.

Oldghm
quote:
Originally posted by Oldghm:
It is important to remember that what is perfectly clear and easy to understand to some of us is murky as swamp water to others.


I believe you and I have spent considerable time together in that swamp, have we not? Smile

Mike
OK, here's a reply....
I guess, after all the posts & advice, etc., I somehow am still somewhat confused, I must be, about something, cause I'm still nagged by feedback, almost every gig, sometimes worse than others....
I use an external mixer, and it the relationship between that & the Bose that I think, is still not clear. I've played professionally 30yrs, been bandleader, with the pa, and set up and handled thousands of gigs, yet this is kickin my butt....

Now, do I want the hottest signal possible coming out of my mixer, first of all? And figuring out what to boost the most, between the channels' individual trims, then their volume, then the master, is also unclear to me. If I pump up the individual channels, via trim & volume knob, what if that then means my master is only at 30%, isn't that "bad", to not have the master even at mid-point?

And if I have a hot-hot signal coming into the Bose, it may mean the trim is at zero, and maybe even the master on the remote may be only at 30% or so, would that be not good, as well?

Maybe you could explain, in some as yet attempted manner, a slightly different perspective on approaching this concept? How would the Zen Master explain this to his young "grasshopper"?

Thanks guys.....
quote:
Originally posted by Saxman7:
...If I pump up the individual channels, via trim & volume knob, what if that then means my master is only at 30%, isn't that "bad", to not have the master even at mid-point?

And if I have a hot-hot signal coming into the Bose, it may mean the trim is at zero, and maybe even the master on the remote may be only at 30% or so, would that be not good, as well?


I cannot see why this should be a problem. I use mine this way and have never had an issue. In fact, I believe this will give you the best signal to noise ratio.

(no Zen Master here, though)

...Mark
quote:
Originally posted by Mark-at-Bose:
I cannot see why this should be a problem. I use mine this way and have never had an issue. In fact, I believe this will give you the best signal to noise ratio.

(no Zen Master here, though)

...Mark

Hmmm....ok, that's good to hear. I've heard so many here say they have the master &/or channels kicked up to like 7 or so, and assumed it's the more optimal spot. But intuitively, I would assume that a hot signal WOULD be better served by a lower "final" gain stage, than a lesser one pumped up by the final setting.

So, I'll try that tomorrow night and see if it works better. I know I will hit the right combination one of these times....

My guitarist told me today how he was amazed at how loud our keyboardist was last night, coming through the PAS. He said it sounded like we were at the Omni (large concert arena), and the Bose didn't flinch at pumping it out.....
Saxman7

No. You do not want the hottest signal possible coming out of your mixer. You want the output meter (LED's??) on your mixer to tell you when you have a "proper" output signal strength.

I have never had a feedback problem. Let me qualify this by saying most of the gigs are just me, one mic and acoustic guitar, but I have on several occasions used the PAS with an outboard mixer, multiple players and as many as 4 open mics.

The remote MASTER is always at or past 12:00, and channels 1 and 2 volume levels are the same as the MASTER.

When using a mixer, I set gain on the mixer just like I would if I were running to a rack full of signal processors and power amps.

In my case, working with unbalanced 1/4" connections the PS1 input gains are very near 0.

Then I use the PS1 and remote as if they were my signal processors,.......because they are.

I select a preset for each channel input that works best for the application, usually all vocal mics panned to channel one, all mics being the same model with the appropriate preset.

I pan instruments to the other channel and have had good results running acoustic guitar, mandolin, fiddle, banjo, upright and electric bass, through preset #49 for acoustic guitar. That is the one I use for my own guitar and I guess it makes me feel comfortable.

If I were working with the same band every night I would likly do some preset experimentation to see if there was one that worked significantly better for that particular band.

The Bose Remote EQ is used in a global way, like you would use a graphic 7, 9, or 27 band EQ, except you only have 3 bands on each of two channels.

Assuming you have the gain set correctly at the PS1 input, (it doesn't matter if you are direct, 1/4" or XLR, with pads or without) you should be able to work without feedback, without attenuating the signal at the MASTER.

I know sometimes it is hard to identify the source of feedback, but the usual suspect is a mic somewhere, and in my experience I have effectively eliminated feedback with individual gain, placement, "and EQ", not overall system volume.

One size doesn't fit all, but I hope there is something here that helps you to get rid of the feedback demon.

I'm no Zen Master either, I just hope that I'm not draging you through the swamp that MTM and I sometimes wallow in. Smile

Oldghm
quote:
Originally posted by Oldghm:
Saxman7

No. You do not want the hottest signal possible coming out of your mixer. You want the output meter (LED's??) on your mixer to tell you when you have a "proper" output signal strength.

OK, herein lies my confusion/problem, Mark-at-Bose just got through telling me the exact opposite. Sooooo......what's a guy to do?
How do I recognize my mixer telling me what the "proper" output, and not the "hottest" output, is?
I take it you are saying the "proper" level is NOT as high w/o peaking as possible, so what should it be then?

quote:

The remote MASTER is always at or past 12:00, and channels 1 and 2 volume levels are the same as the MASTER.

When using a mixer, I set gain on the mixer just like I would if I were running to a rack full of signal processors and power amps.

OK, and what would that look like?

quote:

Assuming you have the gain set correctly at the PS1 input, (it doesn't matter if you are direct, 1/4" or XLR, with pads or without) you should be able to work without feedback, without attenuating the signal at the MASTER.

I know sometimes it is hard to identify the source of feedback, but the usual suspect is a mic somewhere, and in my experience I have effectively eliminated feedback with individual gain, placement, "and EQ", not overall system volume.

The problem is that even when I mute all the other mics but one, I still get feedback, and it's certainly not pointed directly at the PAS, but is in the "general direction" as it's behind me, and the mic is obviously pointing towards me. Should I stand sideways onstage?

And of course I use volume, eq, etc., but there's only so much high end I can take off without making my flute unclear, and if I have to turn the volume down too low, I'm then inaudible. I sure wish there were more posts to the "wind instrument" section of the message board, as, just like in recording & live sound management you have to either play one, or be experienced in working with those who do, to really address this adeptly.

quote:
One size doesn't fit all, but I hope there is something here that helps you to get rid of the feedback demon.

I'm no Zen Master either, I just hope that I'm not draging you through the swamp that MTM and I sometimes wallow in. Smile

Oldghm

Well, finding that "perfect zone" is any musician's lifetime search, and I appreciate the time you took out to try and help me....
Saxman7,

Let me muddy up the waters some more...

I didn't read Mark-at-Bose and Oldham's replies as giving you conflicting advise. I read Mark's reply as "it's not a problem if your Remote master & levels are not at 12:00," and Oldham's reply as "be sure your hot-hot signal from the mixer isn't sending an already clipping signal to the Bose." It won't matter how you gain-stage your BOSE if the signal from the mixer is already clipped.

Anyway, here's how I run my setup. MANY inputs (4 vocals, 3 guitars, bass, a MIDI guitar, 4 drum mics) through a Mackie 20 channel, 4 bus mixer to 2 Bose systems. I run 2 vocals through Mackie submix 1 to lefthand Bose Ch1, other two vocals thru Mackie submix 2 to righthand Bose Ch1, and split the instruments through submixes 3-4 to appropriate side Bose Ch 2's. Hopefully you can visualize this. Now, most mixers have LED meters that allow you to check signal level for each input - I'm assuming yours does as well. On a Mackie, you just push each channel's SOLO button to see that channel's signal on the meter. Before I ever turn on the Bose systems, I check the levels of each vocal mic, instrument mic, etc, adjusting the Mackie's channel trim so the meter runs consistently between 0db to 7db on each channel. As most amplifiers clip at around 10db (at-BOSE guys can tell us when the PAS clips, I'm sure), I target 0db-7db to be sure I'm getting a good hot signal without clipping/distortion.

IMPORTANT NOTE: Most mixers, when soloing a channel, will tap the signal pre-fader and assumes unity gain. This means the mixer assumes each channel fader is at the unity setting when it is displaying on the LED. Therefore, I set all my faders at unity while setting the individual channel gain (trim).

Once I have each channel hitting the meter at 0db-7db, I set each submix (bus) fader at unity gain and power up the Bose. I adjust the trim on Ch1 and 2 of each Bose as described thoughtout the forum - turn it up 'til it just goes red, then back it down to solid green. PERSONAL PREFERENCE PART: I usually back the BOSE trims down a very small touch less than solid green, to give a little breathing room for changes made during the mixing step - to this point, it's all been gain staging. Finally, I turn up the remote CH 1 and 2 level controls to about 12:00 and bring up each master to the desired volume for the room. This completes my basic setup.

From here, I use the Mackie mixer to balance the vocals, and then mix the instruments to the vocals. By starting with all my faders at unity, this leaves me some headroom to turn the female vocalist up without clipping her signal in the Mackie, or fade back on the guitar player, if he's feeling frisky with his stage amp, without getting the Mackie signal too weak before sending it on to the BOSE. I approach our setup this way because, once the Mackie mixer is gain-staged and all signals balanced, I can rely on the remotes for tweaking thru the night. Vocals not cutting thru after the place fills up? Just give remote Ch1 a bump up. Drummer really pounding it out? Drop Ch 2 on the system he's routed to. Need more (or less) overall volume. Two remote master tweaks and you're done.

I hope this descrption wasn't too basic - you may have already tried all this. It sounds like alot of effort, but in reality, if you do right once, you can pretty much leave the mixer alone from gig to gig. Unless, like me, you have mixer fairies who sneak into your house between gigs and turn all the knobs just for fun. Seriously, I had a really good setup on my mixer, and showed up for the next gig and everything had changed - quite odd, since I had control of the mixer the whole time, and I don't use it except at gigs, and I didn't mess with it...

Anyway, I'm sure there are many opinions on how to approach this issue, I just wanted to share what's worked for me.

Mike
Hi, Saxman7…

I went to your web page and it has a picture of you and your flute playing in front of a mic on a stand. I don’t know if this picture is “pre-PAS”, or not…

I know we have touched on this before, and if I remember correctly, you said you had tried this also, but this works for us.

A little background: One of the groups I play in is a Celtic group [guitar, HD & flute (classical and Irish)].Using a mic on a stand (like in your picture), we could never get the flute loud enough w/o feeding back.

The solution I came up with was to get a small condenser mic (Pro 35AX). We tried it at first attached to the flute body with its clip and tiny positioning arm… this was better, but it would seem to move out of position easily and at the most inopportune times.

So… I took it out of its clip, cut a piece of foam (to keep the mic off of the flute body so as to minimize the key-click noise from going to the PAS) and taped it to the flute with painter’s tape (doesn’t leave a residue). This works so well that we can actually get the flute too loud now.

I attached a picture of what it looks like… not very elegant, but works great!

We run her two flutes (two pro 35ax’s) through a small Mackie mixer, and mute the mic she is not using with the channel mute button… very easy and fast.

BTW, in case you’re wondering “What kind of flute is that !!”, I don’t have a flute at home, so to show how the mic is attached, I took a piece of drum stand that was about the same size and drew the embouchure with a sharpie… you can stop laughing now !!

Anyway, hope this helps…
Mike: Thanks for your story, I do make sure the channels on my mixer aren't clipping, and the confusion about the PAS remote master setting is that I was told "less than "12" was ok", and that "it should never be below that", thus the confusion.
I was panning mics to one channel, and md & synth to the other, but then got away from it, and I'll try that again. However, the other night's gig made that moot, as ALL I had on was ONE MIC (& a keyboard going into CH 3), and still had feedback before I could get the volume I needed, and we aren't a rock band, so I'm not talking stadium level volume... :-)

Dandyman: Yeah, I know I could do that, however, all the small mics I have are wireless, which would mean adding the base unit to my rack, and a bodypak, and more "stuff" to carry & deal with on the gig.

Now, in a high-volume situation, or concert, I would use the wireless, cause with monitors, feedback, or too little volume for the flute is a given. But in a smaller club or restaurant locale, I should be able to work it with a stand-mic. I once asked Herbie Mann about that, as he never used a wireless or pick-up on his flute. When asked if he ever gets drowned out by the band, he said, "Never".... of course, he then said, "if they do drown me out, I'll fire their asses"....

My only other option, would be to go buy yet another mic, a small, wired one, for use on smaller gigs. Since purchasing the Bose, I must have bought about eight new mics, and spent almost the cost of the PAS, trying to get my sound right. I've never had this much difficulty with all the sound systems I've used over the past few decades of playing, and we do love the sound, but the "quirks" have been draining, & frustrating....

Thanks to both of you for your suggestions!
Sigh... I had a nice long, educational, funny reply ready ... then I lost my reply window by trying to reply to another note before finishing the first! Frown Oh well.

Anyway - a shorter reply:

All the hooplah about gain staging and settings has mostly to do with noise (signal-to-noise). saxman7 does not seem to be having that problem.

Feedback comes from too much overall gain between a mic/pickup and a loudspeaker. Period.

Three approaches to elminating feedback:
1) reduce overall gain
2) reduce gain of just the "problem frequencies" (those feeding back)
3) break the "coupling" between the mic/pickup and the loudspeaker.

The creativity comes in figuring out the ways in which to do #2 and/or #3 (if #1 is not an adequate solution -- and rarely is).

Use of EQ, Bose presets, and feedback eliminators are ways of doing #2. The "trick" is to do this without also destroying the desirable sound qualities.

#3 is done typically by changing the "geometry" of the relationship between the loudspeaker's "sound field" and the "pickup pattern" of the mic. Thus, that's why people try different mics, different orientations, etc.

So, most discussion related to "gain-staging" is of little relevance to eliminating feedback when "noise" -- or "insufficient volume" is not an issue.

Is there a way to make the mic more directional? If you turn around and face the L1, does it still cause feedback the same as when you are 'off axis' (that is, when your body is not blocking the L1)? If so, then it seems your mic is rather omni-directional, and you need to "break the acoustic coupling" in some way.
Well Dan, none of the million mics I have are omni-directional, so I really don't think it's got much to do with the geometry, except that it does have some to do with the geometry.
Because of the varied instruments I play, the mic is rarely in one set position, and so at various times it will be pointing more up, down, or be at various heights, etc., but I never have it pointing directly at the L1.

And I also can't be chained to always blocking the mic with my body, as I do have to turn and move at times...
Saxman 7,

I think PmP understood, and properly explained what I was trying to say.

I have two different mixers, each with LED meters on the output. They both start with green then have two or three yellow and finally a red. I like to keep mine in the yellow.

I don't think it is absolutely neccessary to have the MASTER at or above 12:00, but I think that is the wrong place to control feedback.

If I understand the system, having the MASTER at 12:00 allows you to use the full potential of the power available, anything less and you are limiting that potential.

You have a difficult situation attempting to use one mic with the same gain for instruments with varying volume levels and performance positions. I have no experience with the flute at all, but I suspect that the sax is much stronger, or louder than the flute, or said another way, the flute requires more gain in order to be heard in the mix. More gain has the effect of making the mic more sensitive thus more likly to feedback.

There is some advantage for vocalists who use the EV 767a and the Audix OM 5, 6, or 7, especially when working very close. I don't know if one of those would be suitable for flute or not, but worth looking into.

Certainly the way you stand on stage can and does affect the potential for feedback, but again that alone is not an effective solution.

What kind of mic are you now using?

What instruments are you playing through that mic?

What other choices (in mics) do you have?

I would give some thought to dandyman's idea of using different mics, through a sub mixer, that will allow you to mute the one you are not using. Perhaps with a little tweaking time you can discover a combination that will let you work at the levels you desire without problems.

Sorry about the mud, but sometimes you just have to wade in and stir things up in order to get on with something that works. Here's hoping you find it.

Oldghm
quote:
Originally posted by Oldghm:
Saxman 7,

You have a difficult situation attempting to use one mic with the same gain for instruments with varying volume levels and performance positions. I have no experience with the flute at all, but I suspect that the sax is much stronger, or louder than the flute, or said another way, the flute requires more gain in order to be heard in the mix. More gain has the effect of making the mic more sensitive thus more likly to feedback.

Well, I usually don't do it this way, (except in small, very low volume places), and didn't start out that way the other night. Often, I would use one up high, for flute/vocal, and another, lower one for my tenor & soprano saxes. That night, I brought my wireless for the saxes, and was going to use one mic for the flute/vocals. There were three other mics (two vocals, one for congas), and I had my wind synth into my mixer, and the keyboard into CH3 of the Bose.

Well, my wireless was feeding back badly from the start, have no idea why, and decided to can it, as I didn't want to be bothered any more. So, I just used the one mic (an EV 967), turning the gain up & down on my mixer depending on what I was playing. I then turned the two vocal mics off unless someone was actually using it, and the one for the congas was the furthest away, and pointing completely away from the PAS.

That's why I was bewildered as to the feedback problem remaining. I basically had ONE MIC, and although I was the closest to the Bose, I was a good eight feet in front, and off center of it.

quote:
There is some advantage for vocalists who use the EV 767a and the Audix OM 5, 6, or 7, especially when working very close. I don't know if one of those would be suitable for flute or not, but worth looking into.

The EV 967 was what I used, the other two vocal mics were 767s, and the percussionist had a Beta 57.


quote:
What other choices (in mics) do you have?

Beta 57,58,87 EV 767,967 two wireless set ups, one with Beyer, the other with a AMT Roam1...

quote:
I would give some thought to dandyman's idea of using different mics, through a sub mixer, that will allow you to mute the one you are not using. Perhaps with a little tweaking time you can discover a combination that will let you work at the levels you desire without problems.

That's exactly what I have been doing...

quote:
Sorry about the mud, but sometimes you just have to wade in and stir things up in order to get on with something that works. Here's hoping you find it.

Oldghm

Well, tonight, at my regular weekend, low volume duo gig, I had no problems. I just used one mic, through my mixer, and my guitarist went into CH3...
Saxman7,

I was sort of rushed last evening to get to a gig so I signed off with thoughts still in my head.

The EV967 has a frequency response up close that is about 50 to 13000 hz, the 767 is 50 to 20000+ hz.

Because you mentioned not being able to cut the highs without adversly affecting the amplified sound of the flute, I wonder if the 767 might be a better choice?

Just thinking out loud. I haven't done any research to see what the frequency range of the flute is, but the 967 is really optimized for voice and may not offer the high end range you need for the flute, forcing EQ adjustments that are not giving the response you want while adding boost where you don't need it.

Maybe a little research in this area (range of instrument compared to response of mic) will help you with getting a match that works well.

I am not a flute player and I don't really know how wide a range you are trying to pick up and amplify but, for example in any high gain situation, mics pick up ambient noise so if you could drastically cut the LOW band maybe that would not affect the amplified tone of the flute and would eliminate part of the feedback prone frequencies.

Oldghm

PS. I realize that you are using the same mic for vocal and flute. Just curious, are you optimizing EQ for the vocal? Or the flute?

I use the 767 for vocal and get lots of volume without feedback while running the EQ nearly flat, maybe just a db or two of boost (Lows & Mids) or cut (Highs) depending on the room or vocal condition.
quote:
Originally posted by Dan Cornett:

All the hooplah about gain staging and settings has mostly to do with noise (signal-to-noise). saxman7 does not seem to be having that problem.

Feedback comes from too much overall gain between a mic/pickup and a loudspeaker. Period.



This is true, but where and how one gets the overall gain does affect feedback.

The reason for singing close to the mic is to take advantage of the gain that is available just by being close.

If a performer tries to accomplish the same overall volume while singing six inches away from the mic as he/she would with lips touching the mic, then a knob somewhere would have to be turned up to provide for the gain lost with the gap between mouth and mic, and feedback is more likly even though overall system volume might be the same.

Feedback free performances with the PAS demands that we take advantage of close micing at every opportunity to avoid unneccessary signal gain at the preamp or the channel volume control.

Oldghm
quote:
Originally posted by Oldghm:
Saxman7,

I was sort of rushed last evening to get to a gig so I signed off with thoughts still in my head.

The EV967 has a frequency response up close that is about 50 to 13000 hz, the 767 is 50 to 20000+ hz.

Because you mentioned not being able to cut the highs without adversly affecting the amplified sound of the flute, I wonder if the 767 might be a better choice?

Just thinking out loud. I haven't done any research to see what the frequency range of the flute is, but the 967 is really optimized for voice and may not offer the high end range you need for the flute, forcing EQ adjustments that are not giving the response you want while adding boost where you don't need it.

That's really very odd, I would have assumed that 967, being the top end mic, and advertised as being most gain before feedback, would have the wider freq. range. Also, many singers have very high voices, so I would think a higher top would be a given.

I found the 767 (as I did the early ND mics) a bit boomy when I sang thru it, or talked. It was ok for flute, but needed a bit more highs (or less lows), and is ok for saxes, but can be a bit boomy. Other cats who sing using the 767 seem to be fine, so it's probably just my voice being on the smoother side...

quote:
Maybe a little research in this area (range of instrument compared to response of mic) will help you with getting a match that works well.

I am not a flute player and I don't really know how wide a range you are trying to pick up and amplify but, for example in any high gain situation, mics pick up ambient noise so if you could drastically cut the LOW band maybe that would not affect the amplified tone of the flute and would eliminate part of the feedback prone frequencies.


Yeah, I usually do lower the bass, as it's more feedback-dangerous to boost the highs.....

quote:
PS. I realize that you are using the same mic for vocal and flute. Just curious, are you optimizing EQ for the vocal? Or the flute?

They are just about the same, I'll usually cut any reverb when singing, (& don't use much on flute either), just for clarity...

quote:
I use the 767 for vocal and get lots of volume without feedback while running the EQ nearly flat, maybe just a db or two of boost (Lows & Mids) or cut (Highs) depending on the room or vocal condition.

Yeah, it's funny, but last night I accidentally used the 767 instead, and did notice my flute/vocal weren't cutting. Then I changed back after the first set, and with the tone switch on the mic set to the "brighter" side, it was better for the vocals & flute. I still am wondering if the 967 with the switch on the "warmer" side, or the 767 is best for my saxes. The 967 on "bright" is ok for my tenor, but too edgy for the soprano...
quote:
Originally posted by Saxman7:
That's really very odd, I would have assumed that 967, being the top end mic, and advertised as being most gain before feedback, would have the wider freq. range.


Saxman7

I suspect that one of the design features that make the 967 "most gain before feedback" is that it doesn't respond to any freq. above 13k hz. I don't think that would affect my vocal. Smile

I find that I make very small EQ adjustments with the 767. It is a rare situation for me to have a EQ control more than 2db + or - from the 12:00 position. Occasionally when singing the lowest notes in my range I will wonder if a syllable or two is clear, other than that I really like the 767 and for my vocal would not call it boomy.

I encourage you to rehearse or practice some without the remote, this will let the PAS operate with system EQ and level controls at the default setting, removing the temptation to "fix" it with the remote.

Continue to use and possibly experiment with the presets.

I am not suggesting you gig this way (without the remote, even though you could) but, if you can go through some exercises that cause and then solve feedback issues using only the mixer to create and then fix the problems maybe when gig time comes you will be better prepared to fix on the fly.

I did a gig a while back that required 3 open mics for a presentation and multiple MC's between acts. When I set the system up I did a short set with two additional mics set identical to my vocal mic and left open. I did not experience feedback.

I don't want you to think I am over simplifying this issue. I know that micing your wind instruments is more difficult than the average vocal. I do believe that a systematic approach to the cause and cure of the problem can lead you to a method that will make your gigs run smooth, and I hope I am giving you ideas that will help you identify and correct the problem areas.

Oldghm

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