Feedback issues with Bose L1 compact and T1 mixer

[Guitar Cowboy]

I recently did my first bar gig with my Bose L1 Compact and T1 and had a terrible time with feedback. Since it was at a bar I was dialed up louder  than I usually am. I had the Taylor a 50%, the Trim on the T1 at about 60%,  the the master volume at 50%, and the guitar channel volume at about 35%. This was all just barely loud enough  to be heard at the back of the room The feedback occurred mostly when hitting the open 6th string - low e . The room sat about 40 people so it wasn't huge . I eventually got it under control by messing with the EQ( lowering the base)  and putting as much distance  and my body between my guitar and the PA . I even put a 2 ft by 3 ft wall  that I had built out of 2X 6s  directly in front of the base module. After doing everything I could think of, I was just barely loud enough.

Its frustrating because these Bose PAs are supposed to be feedback Proof" .  I know this is really a question for Bose, and I will be contacting their tech support as well, but I thought I would see if anyone here could point me in the right direction or offer some suggestions with combating feedback . Thanks

[MB]

Hey Cowboy,
I have an L1 system with the T1 mixer and love it.
Position the L1 off to one side a bit. I keep mine just off my left shoulder. Don't put it directly behind you. After that, gain staging is most important.
I start with the controls on the guitar at the detentes. I typically end up just dialing the low end off on the guitar itself just a tad but do that only after setting the preset and EQ on the T1.

With both channel and master volumes OFF, dial up the GAIN/TRIM on the T1 guitar channel so it just lights green while strumming firmly.
Then use one of the T1 presets for acoustic guitars. Taylor Guitars has several presets, I think one for each body type. The GA preset works great on my guitars. You can update your T1 online if you don't have the presets on your T1.

Then bring up your channel and master volume to around 10-11 o'clock and go to the EQ in the T1 for your guitar channel and find the offending low end frequency and dial it out.
You mentioned your sixth string causing the feedback...so find that frequency on the EQ and then dial it out. Usually around 110 - 125 for me but depends on the room/stage etc.

If using a vocal mic, then use the preset for that mic....I use a 58 but there are many choices.
Again, make sure the GAIN/TRIM is just lighting the green light and not yellow or red.

I hope this helps....
Good Luck!

[Guitar Cowboy]

Thanks, I'll give that a try
When you say dial it out , are you referring to the zEQ or th para EQ function on the T1?

[MB]

I think it's the Para EQ. It is the one you can pick the frequency and then reduce the gain for that frequency.
The process is like this....
Once you have your gain light lighting up green, then turn up the volumes to 11 o'clock or so.
Then pick the string(s) that are producing the feedback note.
Turn the gain on the low band of the EQ up to emphasize the feedback.
Then go to the frequency selection and turn that to "scan" the frequencies until you find the sweet spot of the offending frequency.
Then just turn the gain for that frequency band down with the low end EQ gain control.
You can also adjust the "Q" or width of the frequency cut.

You will also see that each frequency is associated with a Note on the musical scale. For example, 110 hz is an "A" note. 98 hz is a G note.
So if your feedback is coming from your sixth string fretted at the 5th fret, you'll know that the "A" note is about 110 hz.
I set the Q on the para EQ to cut between 100 and 120 and cut about 6 db and that usually tames it down enough.
Sometimes you'll encounter 2 bad frequencies....that's when I use the bass control on the Taylor ES2 to dial out the low end a bit overall.

[MrHarryReems]

I think it's the Para EQ. It is the one you can pick the frequency and then reduce the gain for that frequency.
The process is like this....
Once you have your gain light lighting up green, then turn up the volumes to 11 o'clock or so.
Then pick the string(s) that are producing the feedback note.
Turn the gain on the low band of the EQ up to emphasize the feedback.
Then go to the frequency selection and turn that to "scan" the frequencies until you find the sweet spot of the offending frequency.
Then just turn the gain for that frequency band down with the low end EQ gain control.
You can also adjust the "Q" or width of the frequency cut.

You will also see that each frequency is associated with a Note on the musical scale. For example, 110 hz is an "A" note. 98 hz is a G note.
So if your feedback is coming from your sixth string fretted at the 5th fret, you'll know that the "A" note is about 110 hz.
I set the Q on the para EQ to cut between 100 and 120 and cut about 6 db and that usually tames it down enough.
Sometimes you'll encounter 2 bad frequencies....that's when I use the bass control on the Taylor ES2 to dial out the low end a bit overall.

I've noticed that my Taylors tend to be extremely strong in the 120hz range.  I have a preset in my digital mixer set with a pretty deep cut there.

[Guitar Cowboy]

I have not had a chance to try this out yet , but I plan to. Thanks for the advice .

[paulin]

Steve,

Which of your Taylor guitars were you using?  Were you using a TRS or TS cord?

Paul

[Guitar Cowboy]

I was using my 618 and K26 with a TRS balanced cable   from the T1 to the L1

[Edward]

Data point: TRS vs TS is a non issue with regard to tone and/or feedback.  The difference between the balanced and non-balanced signal is capability for long cable run without signal degradation, and a 3db increase in volume, a significant difference to be sure, but neither of which will affect the resultant tone nor diminish/augment feedback.

The nature of feedback is entirely one of frequency (Hz), volume, and proximity: adjust any one or a combination of these and you will create, diminish, or eliminate feedback entirely.

Sounds like you already took a shot at "proximity" as you adjusted position of this and that.  Also try getting behind the plane of the speakers, or standing farther to the side of them ...this becomes a bigger deal as volume goes up!  So if you are struggling with volume (being heard at the back of the room) while getting feedback, your recourse is finding the frequency to notch.  Mr.Reems suggested attenuating 120Hz; try this.  It has been my personal experience with acoustics (Taylors and otherwise), that around this 120-180Hz as well as around the 500-600Hz ranges is where acoustics can tend to feedback given enough volume and proximity to a speaker.  I don't know the L1 system to give you specific advice, but situations like this is where multi-band parametric EQs are worth their weight in gold.  FWIW, I used to use a Presonus parametric that was small and inexpensive, and perfect for finding offending frequencies.  BTW, feedback also is affected by the room so while you may find the right frequencies to notch for this particular guitar, it may change +/- a hair when in a different room ...or a non issue outdoors   Hope this helps you a bit

Also, which ES is this?

Edward

[Earl]

The Bose system line array is resistant to feedback, but not immune.  Even Amar Bose cannot re-write the laws of physics for acoustics or electronics. 

It is always bad news when the microphone has a direct view of the speakers, just a bit less so with Bose.  Since very low frequencies from subwoofers are almost omni-directional, it can be really hard to get out of the way of the bass waveform.  Sometimes there is an unfortunate coincidence of dimensions.  The wavelength of 120 Hz sound is 9.4 feet, and the peaks of that waveform occur at the 1/4 and 3/4 points of that wavelength (2.4 feet and 7.1 feet).  If your mic or guitar top happens to be at one of these anti-node points, you are way more prone to feedback.  At least get the bass module placed well ahead of you, even if your perception of the bass in the mix is not to your liking.  The stage mix for the performer is one thing, and a good front-of-house mix for the audience is a whole different story.

As Edward and others have mentioned, you have to change something -- EQ of the guitar or the PA, position of the microphone relative to the column, volume level, or.......   This is a case of experimenting until you find what works for your combination of equipment, playing style and desired volume / tone.

[Guitar Cowboy]

Thanks everyone  for your  feedback .. ha ha . I will be trying to make some adjustments prior to my  next bar gig at the end of the June.  It looks lie I'll need to rely on the para EQ function  as I have the other two issues working against me... its a small "stage" area so I cant  get too far away from the Bose  and I have to crank it all the way to 11  in order  to be heard in he back of the bar.  So I'll move the base module ahead of me and off to the side  and play around with the T1 . 
 To answer Edwards question , both guitar s I brought last time had ES 2 and both had issues.

 Thanks  Everyone , I'll let you know how it goes !!!!

[Edward]

The reason I asked about which ES is that I've found the ES1.2 and ES1.3 to be incredibly feedback resistant; and with the ability to switch off the body sensor(s) and rely solely on the fretboard pickup, even more so.  The ES2 is a piezo UST is still fairly good at resisting feedback, though.  Can you position the L1 stick and sub as far forward with you somewhat behind it?  That will go far in getting you more gain before feedback.  A multi-band parametric is still what you want, but everything in sum counts.  Try setting up at home in, say, a garage to approximate the footprint of all your gear and see what repositioning can buy you...

Edward

[Guitar Cowboy]

Yep that's what I plan to do... set up in  my basement  and see how I can adjust the para EQ on the T1 module. The last time I played in a bar ( also the first time I played in a bar)  I was able to reduce feedback  by just dialing back the base on the guitar and  the T1. I wasn't familiar with the para eq function on the T1  at the time , so I'll try to get there before my 6/29 gig. Thanks

[Guitar Cowboy]

I have been getting ready for my gig tonight, trying to combat feedback  in my basement. I found out this week that the offending frequency for my basement set up is 138.6 Hz =C#. I am tuned down a 1/2 step so I've been getting  feedback on the open D ( C#) and 5th fret of the 5th string. Per suggestions above ( thank you!!! ) , I have put the Bose  L1 Compact in front of me to the right and I think that has helped a lot... allowing me to go a bit louder as I try to approximate how loud I will need to be at the bar tonight. Putting the L1 off to the side behind me didn't seem to help.  Using the Para EQ on the T1, I was able to dial down the offending frequency  by 15 dB .  It helped a little  but couldn't cut the feedback  with the volume I was at. I also tried a sound hole plug , but that didn't do it either. Conclusion: I am just too close and too loud. In my basement,  I could have increased the distance  between me and the  L1 , but I wont be able to do that too much at the bar. What did finally work was rather simple ...  taking one step ( yes , just one step)  to the left. Feedback gone!

Thanks again for all your suggestions We'll see how it goes tonight and I'll use whatever tools I need . Wish me luck !!! Thanks!

[Guitar Cowboy]

Just reporting back  that the gig went fine. I placed the Bose L1  about 5 ft in front of me off to the right. The only negative was that  I wasn't able to hear my guitar as well as I would have liked so it was a little weird . It sounded like  my vocal volume was way too high  compared to the guitar. But I had several friends check the back of the room  and they seemed to think the balance was good. The bartender also said it seemed that I was easier to hear this time around vs. my  1st gig,  so maybe I bumped up the vocal volume closer to where it should be.

Is there a  general rule of thumb for  vocal  volume  vs. guitar volume  that I should keep in mind in the future?
Thanks again for all your help.
 Steve