Live and Loud - Feedback Please

[debra]

. . . You can also try to find out which note resonates the most through the floor and use an equalizer to dampen that note. (When I have time to set up I always look for that and eliminate the problem with the Bose Tonematch engine.) . . . 

[font=Tahoma, sans-serif]Paul,[/font]

[font=Tahoma, sans-serif]I have a question on setting up the equalization on the Bose Tonematch.  I am trying to reduce resonance at A2 = 110 Hz.  I am Selecting Para EQ band 1.[/font]
[font=Tahoma, sans-serif]1st, I rotate the Level control to -12 dB[/font]
2nd , I rotate the Freq control to a center frequency of 110 Hz
3rd , I press the Freq control to switch to  Width and set the bell curve width to 0.2 octave
 
I can hear the “cut” in output.  My question is:  How can I tell afterward, that I have set a -12 dB cut at the center frequency of 110 hz?  If I rotate the Freq control from 50 Hz to 16 kHz, all the frequencies show a -12 dB cut.  I thought I would see the “bell curve” drop off with a peak at 110 Hz and a drop off to 0 dB at +/- 0.1 octave.
 
John

Easy: when you rotate the freq control you are changing the frequency at the center of the "bell". You cannot see how much other frequencies are actually being cut off. Typically what I use is a setting of -6db and 0.5 octave. There is no miracle cure to cut out just one frequency and a very narrow band may have distortion as side-effect (I remember this from my days of configuring analog electronic filters).
My experience is that with -6db and 0.5 octave I don't notice the "cut" but I can up the volume a bit more without feedback.
Miracles to not exist, especially not when you are pointing speakers towards the microphone, but as I would like to continue enjoying listening to music for a few more decades I don't need to up the volume to a point where my hearing will not last more than just one gig...

 

[John M]

. . . You can also try to find out which note resonates the most through the floor and use an equalizer to dampen that note. (When I have time to set up I always look for that and eliminate the problem with the Bose Tonematch engine.) . . . 

[font=Tahoma, sans-serif]Paul,[/font]

[font=Tahoma, sans-serif]I have a question on setting up the equalization on the Bose Tonematch.  I am trying to reduce resonance at A2 = 110 Hz.  I am Selecting Para EQ band 1.[/font]
[font=Tahoma, sans-serif]1st, I rotate the Level control to -12 dB[/font]
2nd , I rotate the Freq control to a center frequency of 110 Hz
3rd , I press the Freq control to switch to  Width and set the bell curve width to 0.2 octave
 
I can hear the “cut” in output.  My question is:  How can I tell afterward, that I have set a -12 dB cut at the center frequency of 110 hz?  If I rotate the Freq control from 50 Hz to 16 kHz, all the frequencies show a -12 dB cut.  I thought I would see the “bell curve” drop off with a peak at 110 Hz and a drop off to 0 dB at +/- 0.1 octave.
 
John

Easy: when you rotate the freq control you are changing the frequency at the center of the "bell". You cannot see how much other frequencies are actually being cut off. Typically what I use is a setting of -6db and 0.5 octave. There is no miracle cure to cut out just one frequency and a very narrow band may have distortion as side-effect (I remember this from my days of configuring analog electronic filters).
My experience is that with -6db and 0.5 octave I don't notice the "cut" but I can up the volume a bit more without feedback.
Miracles to not exist, especially not when you are pointing speakers towards the microphone, but as I would like to continue enjoying listening to music for a few more decades I don't need to up the volume to a point where my hearing will not last more than just one gig...

Thanks Paul,
I do notice that I can up the volume more without feedback once I reduce the resonant frequency.  I guess once I adjust for the loud frequency I am cutting, I will have to track it elsewhere to remember which frequency it was.  I don't have much problem with the treble side of the the accordion.  It seems to be coming from the microphone that is installed in the bass section.  Also, it seems to be a characteristic of the volume of certain notes in the stradella bass of my excelsior 960 and not so much a room resonance problem.  So, it is a constant frequency that want to reduce at all times.
John

 

[debra]

Thanks Paul,
I do notice that I can up the volume more without feedback once I reduce the resonant frequency.  I guess once I adjust for the loud frequency I am cutting, I will have to track it elsewhere to remember which frequency it was.  I don't have much problem with the treble side of the the accordion.  It seems to be coming from the microphone that is installed in the bass section.  Also, it seems to be a characteristic of the volume of certain notes in the stradella bass of my excelsior 960 and not so much a room resonance problem.  So, it is a constant frequency that want to reduce at all times.
John

If it is a matter of where the mic is placed on the bass side then indeed it will be a constant frequency you want to reduce at all times. The tonematch engine will remember the value so you don't need to search for it each time.
In my case it was always depending on the floor and the speaker placement, so the frequency was not the same every time.

 

[John M]

If it is a matter of where the mic is placed on the bass side then indeed it will be a constant frequency you want to reduce at all times. The tonematch engine will remember the value so you dont need to search for it each time.
In my case it was always depending on the floor and the speaker placement, so the frequency was not the same every time.

Paul,
The information you have posted here on the Tonematch has really helped me get the most out my Bose L1 Compact. The first was when I found out about the “accordion” equalization preset. And now finding out how to use the Parametric Equalization to even out the response of the bass side of my accordion. It’s all in the “fine tuning” that really adds a lot to the quality of the final output from the Bose L1 compact.
Thanks,
John

 

[Mr Mark]

debra - I am seriously curious as to how well your setup would work in a small venue with a rock outfit pushing 120-130 dbs.  We are definitely too loud for our own good but that is beyond my control   .  It would be good to hear some samples of your ensemble at work!

Here is an illustration of the problem Im referring to:
You can clearly hear the problem of a low bass note going through the floor.
We could have eliminated it is we had more time to diagnose the problem...

Here is a video without problem: in a different venue. You can make out one Bose L1 model 2 pole. We used two of them.
Everyone except the bass player is using a Microvox 420 unit. (The bass came with Sennheiser mics built in.)

We try to offer our audience a concert experience, not a lets see if we can destroy your ears experience.
That makes our life easier.

Ha!  That last line made me laugh!  Apt!

Great performances!  I cannot hear the low bass issue you are referring to.  I will have to listen again.  By all accounts your sound system sounds great though.

---

To paraphrase: Waldo Emerson once said, if you want to go on a journey, you can either spend months or years working to get enough money to buy an outfit ( horse, cart, etc) for the trip, or simply set off on foot right away.

It rather seems to me that this parallels the issues on this thread: you can either pick up and play your acoustic instrument right away or spend months/years tweaking your electronic equipment instead.

The reason for all this appears to be to produce sufficient volume to be heard, but doing so, constantly introduces unwanted complications . And so it goes on.

When I was a boy, none of this gear had even been dreamed of, yet musicians (even accordionists) appeared to have no trouble making themselves heard. Have we lost our hearing? Have instruments lost their capacity to project?

The chief advantage of acoustic instruments has always been their independence of a power supply: just you and them

Sage words.  This entire experience has definitely contributed to me rethinking my role in all of this.  My intentions going in certainly werent where I have ended up, so getting back to the root of the matter is well and truly in order - just me and my instrument, as you say.  


I think for the most part my setup will serve me well (with some further tweaking) - just not with a band that has volume control issues  .


Again, I appreciate everyones input.  Lots of great information here!

 

[Waldo]

How to solder:

1) Select the appropriate soldering tool and heat your iron for 15 mins. or so.

2) Using a toothbrush size brass or stainless steel brush, brush the heated tip until free of contaminants .

3) Choose the proper solder (rosin core for electronics, acid core for non-electrical applications) in a small diameter form. Use Tin/Lead alloys on copper wire. NEVER USE ACID CORE SOLDER ON ELECTRONICS!!!! Acid core solders are usually a large (1/8"/3mm, plus) diameter, compared to rosin core that is half that diameter. Key word: Usually! Check the box or roll for specs. If in doubt, don't use it or corrosion may result.

4) Tin the tip by melting a small amount of solder on the hot tip (don't overdo it), but assure complete tip coverage.
If the solder won't adhere, reclean tip using a salimoniac block or emery cloth until shiny...re-tin as above. Very important! If it still fails to stick, oil is present and needs to be removed (use acetone) before going any further.

5) Join wires to be soldered by some means so they won't separate during the process. See below.

6) The Trick: Apply a small amount of solder to the top edge (not the end [tip]) of the iron. The idea is to form a small molten lump of solder on the top surface of the tip. Applying too much solder will result in the lump migrating to the bottom of the iron and falling off. Bring this lump into contact (preferrable from below, as heat rises) with the item to be soldered and wait until the wires come up to the temp that will melt the solder. With small (22ga and above) wire this will take a second or two. Larger wires take more time. The solder lump is the key. The temperature of the material to be soldered must reach the melting point of the solder, or an aptly named "cold joint" will result. Simply placing the naked iron tip against the wires results in poor heat transfer and cold joints. The lump serves to provide a conduit for the transfer of said heat to the wires.

7) While heating the joint from below, apply the solder "stick" (3" of unrolled solder) to the top of the wire bundle as if trying to push it down.

8) When the "stick" melts, add only enough solder to encapsulate the joint.

9) Remove the heat source and the solder "stick" and allow the joint to cool without movement (5-10 seconds). Movement at this point in the process can result in a "hidden cold joint". Cold joints are recognizable by their frosty appearance. A good joint will be shiny with the "flow" of the joint smooth and uniform. A "hidden cold joint" can be difficult to spot as the "cold" part is inside the joint, a result of the wire moving within the joint (while still liquid) as the outer surface solidifys. Two allagator clips joined by 12 ga solid copper wire ( 3-6" long) work well for isolating movement when soldering, and can be bent into the required shape for your project.

10) Once cooled, carefully remove the flux (rosin, the brown stuff) from the surface of the solder joint so it doesn't break loose and find it's way into a reed. It is brittle, so comes loose easily, and flys around when dislodged, so cover the interior if doing this in an open accordion.

The most common solder problems come from a contaminated joint surface (or iron tip) or failure to heat the subject material to solder melt temp. Get some wire scraps of similar diameter and practice the method described above before attempting to solder the prime pieces. Use a pencil iron, not a gun, for small (wires) jobs. Guns can overheat electronic gizmos and maybe even let the smoke out. Match the right tool to the job!
Solders can be used to join dissimilar metals together, providing the proper alloy and flux are used.

Wires: Tape sucks! As mentioned earlier, Gaffers Tape is the ONLY long term option with tape. Can be found at theatrical supply places or online. Most tapes have their intended application included in the name, to wit: Duct tape; for sealing air conditioning ducts. Masking tape; for masking surfaces to prevent paint coating, Scotch tape; for use by misers, etc. I have used many different tapes in my lifetime, and Gaffer's is by far, the best, although difficult to find. You'll know you have the correct stuff if it is a complete bitch to strip the tape off the roll. Usually found in black or white.

Another, and I think better approach to securing the wires is to use a putty. My favorite is Museum Putty. It's designed to secure museum pieces to their display stands to prevent their loss in an earthquake. It holds stuff well, won't dry out, removes quickly and cleanly without leaving a residue behind. Can even be used on the external surfaces if needed, without damage. Excellent for temporary uses. I'm sure there are other products that would work just as well. Can be used for sealing wire holes as well and alows easy removal if desired, unlike hot glue and other adhesives.

BTW; I use a Myers 3 mic, stuck on by a suction cup, pick-up. Only issue to realize before purchase is weather or not the suction cup will adhere at the preferable location. On my smaller Beltuna, The name "Beltuna" is inscribed in relief on the front surface of the treble side case. This irregular surface prevents use of the suction cup. My other 'Tuna has the logo printed on the case and works well. It is common fot the manufacturers name to appear here in raised letters, also preventing ithe suction cup's use in that location (the prime spot for a Myers accordion P/U). I haven't used it much, yet, but like what I have heard so far. Being 70 years old, 10+ on the volume control will not be an issue for me.

Press on....
Waldo

 

[jozz]

I've been wanting a thorough explanantion like this for a long time, because I suck at soldering. Barely keeps together my own mic systems.

THANKS!

 

[Dingo40]

Waldo,

What a great exposition of soldering!
In the best textbook tradition. Thanks

 

[JerryPH]

Impressive, very well explained, Waldo... well done.

 

[Mr Mark]

Fantastic solder tutorial post!  I must spend some of this downtime doing some practice runs with this new found information.  I have spent almost 250$ in my own solder equipment, then gas/parking and two other soldering services to have all the soldering done in this thread (thankfully the last guy in the chain did a great job)...hopefully never again.  Thank you greatly for your input!

And yes, I'm sure the Myers setup will work fine at less than maximum volumes!

 

[Glug]

I bought a new soldering station a couple of weeks back, but mainly for waxing

If you look on Amazon for temperature adjustable soldering irons there are loads, but mostly they do 200C to 450C.
However there are several that do 90C to 450C and 150C is about right for accordion wax.

Previously I was using a non adjustable soldering iron and it always resulted in a few bits of burnt wax.

 

[Pipemajor]

I bought a new soldering station a couple of weeks back, but mainly for waxing

If you look on Amazon for temperature adjustable soldering irons there are loads, but mostly they do 200C to 450C.
However there are several that do 90C to 450C and 150C is about right for accordion wax.

Previously I was using a non adjustable soldering iron and it always resulted in a few bits of burnt wax.

Can I just add. Don't use solder that has been kicking about in you're  toolbox for the last 20 years.!
I tried to tin my soldering iron yesterday and, no matter how much I cleaned and filed , the solder wouldn't  tin the tip.
Tried some fresh solder and it worked fine  :blush:

 

[debra]

...
Can I just add. Don't use solder that has been kicking about in you're  toolbox for the last 20 years.!
I tried to tin my soldering iron yesterday and, no matter how much I cleaned and filed , the solder wouldn't  tin the tip.
Tried some fresh solder and it worked fine  :blush:

Interesting. I still have and use an old role of solder, bought shortly before solder for electronics, containing lead, was banned.
That solder still works just fine. It is thin and probably contains a bit more resin than thicker solder.
New solder that is lead-free does not work better for me than old solder with lead.
(I know the health hazards. I don't do soldering a lot anymore. Accordions don't require a lot of solder, just occasionally to install a mic.)

 

[Pipemajor]

...
Can I just add. Don't use solder that has been kicking about in you're  toolbox for the last 20 years.!
I tried to tin my soldering iron yesterday and, no matter how much I cleaned and filed , the solder wouldn't  tin the tip.
Tried some fresh solder and it worked fine  :blush:

Interesting. I still have and use an old role of solder, bought shortly before solder for electronics, containing lead, was banned.
That solder still works just fine. It is thin and probably contains a bit more resin than thicker solder.
New solder that is lead-free does not work better for me than old solder with lead.
(I know the health hazards. I don't do soldering a lot anymore. Accordions don't require a lot of solder, just occasionally to install a mic.)

Thinking back it has  been in my toolbox for over 30 years since my previous life as a computer systems  engineer, in the days when we actually repaired things,  so it probably got contaminated along the way. Funnily enough, after I had tinned the soldering iron tip with fresh(er) solder, I tried the original solder and it worked fine.

 

[Mr Mark]

Well, it's been a while and some things have changed so thought I should update this.

I've upgraded my speaker to an EXM Mobile by Yorkville. It is a small battery powered amp with three XLR/1/4" combo inputs with an XLR out. I have also added a Triton FEThead inline audio booster and a small mixing board to my arsenal.

I use the sm58 glued into my accordion wired to a 1/4" out. From there I use my mono wireless 'guitar' system and have the receiver plugged into the mixing board. I run a single 1/4" out of the mixer into the speaker. The reason for the mixing board is so I can EQ things, when the bass player is around I cut my bass frequencies, and when he is not around I boost them. The only reason I have the FEThead is when I am doing my own thing (no band) and I don't need to EQ to fit in - and thus do not need to pack a mixing board around. The speaker acts as my stage monitor and/or my own PA on my own.

There is still significant hiss, no matter how I gain stage this is the case. But, I can really crank this setup with very little feedback issues - this includes when running all over the place on stage.

I think one of the problems I was having was the previous speaker system (TVM50) was prone to feeding back no matter what I did. The EXM Mobile absolutely cuts through - both the fiddle player and I use one and we manage just enough volume to keep up when the rest of the band is going full volume...which is always . To all ends so far I can't recommend this amp enough.

I am still looking into adding a noise gate to deal with the hiss when I am not playing anything.

I'm not sure I'm interested to pursue my other mics further - I'll probably just sell them. At some point in the future if I can, I may get a really nice accordion with mics from the factory. If not, and I needed to, I would probably just go with another 58 (probably better than that) dynamic glued inside. It works.

 

[jozz]

good to hear that you finally have a working solution!

 

[AccordionUprising]

Well, it's been a while and some things have changed so thought I should update this...

Great you found a solution that works Mark!

I wonder if you might give us a summary of your end result? This has been an awfully long project. One post I can refer people to or quote, would be really helpful as a "What Mark does to play loud without feedback."

I may ask for permission to reprint it on my AccordionUprising.org blog too if you like.

Again, glad to hear your results! Direct message me if you want.

 

[JIM D.]

I've always used a 3" piece of bellows tape glued to the bellows fold in lieu of any type if adhesive tape.

 

[debra]

I've always used a 3" piece of bellows tape glued to the bellows fold in lieu of any type if adhesive tape.

That's a good tip! The adhesive of any type of adhesive tape in the end always lets go, perhaps due to age, moisture, temperature or any other reason.

 

[jozz]

I'm not sure I'm interested to pursue my other mics further - I'll probably just sell them.

Do you have one intact Midifisa system with 3 capsules? That is, not destroyed by a bad soldering job... How long is the treble strip exactly? I might take it off your hands to replace my 2 capsule treble strip. Hopefully it is a direct replacement.

let me know