Topic: Bass distortion

[Adam.]

I know it's been said and done, but could I have some specific help? I'm using AT831's into a 3-wire battery box, and the only gig I've recorded was really bassy, and it was overloading it.

Here is a sample of it:

http://www.mediafire.com/?6mqnqmtwcmo

After listening to the attached file:
- Is there any chance of saving this?
- Is this a hardware overload (as in the mic can't handle that higher pressure of air at those frequencies?)
- Is this is a power issue? (ie would 2-wire (with the 4.7k resistor) be better off?)
- Do the 853's (or something similar in cost) have better handling of bass if it is fact a hardware issue?
- Would a battery box with a bass rolloff not be of any use if it is exceeding the limits of the mic?

Thanks for the help in advance, I very much appreciate it!

[Church-Audio]

I know it's been said and done, but could I have some specific help? I'm using AT831's into a 3-wire battery box, and the only gig I've recorded was really bassy, and it was overloading it.

Here is a sample of it:

http://www.mediafire.com/?6mqnqmtwcmo

After listening to the attached file:
- Is there any chance of saving this?
- Is this a hardware overload (as in the mic can't handle that higher pressure of air at those frequencies?)
- Is this is a power issue? (ie would 2-wire (with the 4.7k resistor) be better off?)
- Do the 853's (or something similar in cost) have better handling of bass if it is fact a hardware issue?
- Would a battery box with a bass rolloff not be of any use if it is exceeding the limits of the mic?

Thanks for the help in advance, I very much appreciate it!

Hi the two wire mod would help you out big time.... I invented that mod. and I can tell you I just measured a pair of 853's the distortion is 15% !!!! at 114db at 1k My cardioids after the mod by comparison are 0.5% distortion at 114db. So this mod does work and does reduce distortion it does however lower gain about 10-15 db.. But that gain is made up by an external preamp the distortion level after the mod is 0.5% !!! at 114db at 1k.. So the distortion goes down big time the levels are about the same if you went with three wire but you get much less distortion then you do with three wire. I have measured the same mics with three wire to be at 7% distortion thats still a huge amount. So now the mics can pretty much handle any thing you can throw at them. They will not distort and the sound of the mic is unchanged if you combine this with my st-9100 preamp you will see levels of +5 db at 115 db or Unity gain at acoustic levels of 100db so the functionality of these mics is now suited for SPL levels of 90 to 125 db with minimum distortion and with the use of an external preamp you will still get good levels to your recorder.. With out an external preamp these mics can be used with devices like the r-09 using the internal preamp with no external battery box required!! but at a higher signal to noise ratio with the external preamp the signal to noise ratio is reduced and the quality of the recording increases due to reduced noise floor...

Chris Church



.

[SkttrWave]

Will that mod work if i just make an extension cable for my mics (at933's terminated together in a single miniplug) with a resistor in between the shield wire?
That way i can just leave my mics the way they are and put a simple extension cable between mics and the battery box to prevent distortion.

[Church-Audio]

Will that mod work if i just make an extension cable for my mics (at933's terminated together in a single miniplug) with a resistor in between the shield wire?
That way i can just leave my mics the way they are and put a simple extension cable between mics and the battery box to prevent distortion.

In order to do this mod you need to run your mics with a mini XLR connectors and make an adaptor that connects a 4.7k Metal film 1% resistor between the Yellow wire and ground... This can also be done by chopping the connector off and re soldering with the resistors in place... Its very hard to get the resistors in a small space. I am going to be offering a breakout box that will have this mod in it and it will be switchable so that the mod can be removed from the mics when they are used for lower SPL shows it will be a small box about 1x1 with two mini XLR connectors and one 3.5 mm output stereo to go to a external preamp or battery box or mic input.. There will be a small switch on the box to bypass the resistor so that it can be taken out of the circuit. when Not needed. It will function as an external pad for AT mics allowing them to capture loud shows with NO distortion... I would really appreciate it if no one built these boxes and sold them since it was my idea but I am sure they will show up on the market somewhere. I don't know what its going to sell for yet.

[SkttrWave]

Will that mod work if i just make an extension cable for my mics (at933's terminated together in a single miniplug) with a resistor in between the shield wire?
That way i can just leave my mics the way they are and put a simple extension cable between mics and the battery box to prevent distortion.

In order to do this mod you need to run your mics with a mini XLR connectors and make an adaptor that connects a 4.7k Metal film 1% resistor between the Yellow wire and ground... This can also be done by chopping the connector off and re soldering with the resistors in place... Its very hard to get the resistors in a small space. I am going to be offering a breakout box that will have this mod in it and it will be switchable so that the mod can be removed from the mics when they are used for lower SPL shows it will be a small box about 1x1 with two mini XLR connectors and one 3.5 mm output stereo to go to a external preamp or battery box or mic input.. There will be a small switch on the box to bypass the resistor so that it can be taken out of the circuit. when Not needed. It will function as an external pad for AT mics allowing them to capture loud shows with NO distortion... I would really appreciate it if no one built these boxes and sold them since it was my idea but I am sure they will show up on the market somewhere. I don't know what its going to sell for yet.

cool, thanks a lot. So basically there's no way of applying this mod and leaving my AT's from SP the way they are now (with the single miniplug).
In that case, I think i'm going to terminate each of my mics in single miniplug and then build an adapter cable with the resistor, or just buy your box.

[Church-Audio]

Will that mod work if i just make an extension cable for my mics (at933's terminated together in a single miniplug) with a resistor in between the shield wire?
That way i can just leave my mics the way they are and put a simple extension cable between mics and the battery box to prevent distortion.

In order to do this mod you need to run your mics with a mini XLR connectors and make an adaptor that connects a 4.7k Metal film 1% resistor between the Yellow wire and ground... This can also be done by chopping the connector off and re soldering with the resistors in place... Its very hard to get the resistors in a small space. I am going to be offering a breakout box that will have this mod in it and it will be switchable so that the mod can be removed from the mics when they are used for lower SPL shows it will be a small box about 1x1 with two mini XLR connectors and one 3.5 mm output stereo to go to a external preamp or battery box or mic input.. There will be a small switch on the box to bypass the resistor so that it can be taken out of the circuit. when Not needed. It will function as an external pad for AT mics allowing them to capture loud shows with NO distortion... I would really appreciate it if no one built these boxes and sold them since it was my idea but I am sure they will show up on the market somewhere. I don't know what its going to sell for yet.

cool, thanks a lot. So basically there's no way of applying this mod and leaving my AT's from SP the way they are now (with the single miniplug).
In that case, I think i'm going to terminate each of my mics in single miniplug and then build an adapter cable with the resistor, or just buy your box.

I prefur mini xlr only because they make a better connection but a good set of Neutrik connectors can be just as good if you find a nice jack to go with it check this stuff out at BTX they make a locking 3.5 mm connector and female it would be perfect for your mod and would allow you to make a locking set of connections like mini xlr.
http://www.btx.com/Categories.aspx?Category=4348ad2f-1b43-47dc-83b3-5cee8464acbf

These are the same connectors Sennheiser uses for the wireless mics and body packs they were great and you can actually do the mod inside the female its huge lots of room in there...

[SkttrWave]

I prefur mini xlr only because they make a better connection but a good set of Neutrik connectors can be just as good if you find a nice jack to go with it check this stuff out at BTX they make a locking 3.5 mm connector and female it would be perfect for your mod and would allow you to make a locking set of connections like mini xlr.
http://www.btx.com/Categories.aspx?Category=4348ad2f-1b43-47dc-83b3-5cee8464acbf

These are the same connectors Sennheiser uses for the wireless mics and body packs they were great and you can actually do the mod inside the female its huge lots of room in there...

thanks a lot for the tips. Tho i think i'm going to find a shop here in holland.. saves me some shipping costs

[Church-Audio]

I prefur mini xlr only because they make a better connection but a good set of Neutrik connectors can be just as good if you find a nice jack to go with it check this stuff out at BTX they make a locking 3.5 mm connector and female it would be perfect for your mod and would allow you to make a locking set of connections like mini xlr.
http://www.btx.com/Categories.aspx?Category=4348ad2f-1b43-47dc-83b3-5cee8464acbf

These are the same connectors Sennheiser uses for the wireless mics and body packs they were great and you can actually do the mod inside the female its huge lots of room in there...

thanks a lot for the tips. Tho i think i'm going to find a shop here in holland.. saves me some shipping costs

My stepfather is from Holland, I will ask him if he knows of any suppliers he is down there all the time and is into electronics as well..

[SkttrWave]

My stepfather is from Holland, I will ask him if he knows of any suppliers he is down there all the time and is into electronics as well..

if he knows a good supplier it'd be great if you could pass it through to me.. thanks again for your help

[Carrera2]

Will that mod work if i just make an extension cable for my mics (at933's terminated together in a single miniplug) with a resistor in between the shield wire?
That way i can just leave my mics the way they are and put a simple extension cable between mics and the battery box to prevent distortion.

Hey Chris:  I'm confused.  If the mod can be done in a 1/8" plug where two mics teminate, why couldn't the mod be done at the male end of a small extension cable?

I like your idea of a small switch box.

[Church-Audio]

Will that mod work if i just make an extension cable for my mics (at933's terminated together in a single miniplug) with a resistor in between the shield wire?
That way i can just leave my mics the way they are and put a simple extension cable between mics and the battery box to prevent distortion.

Hey Chris:  I'm confused.  If the mod can be done in a 1/8" plug where two mics teminate, why couldn't the mod be done at the male end of a small extension cable?

I like you idea of a small switch box.

Ok the reason why it can not be done to a male end of a small extension cable is simple. The wires the go into your 1/8th inch stereo jack from the mic are Red Yellow and Ground These are in each line coming from each individual microphone. The Red wire goes to the tip or ring of the stereo connector. Then there is a Shield wire that goes to ground, then there is a yellow wire inside the connector that gets shorted to ground. When you buy these mics from Sound Professionals this is how they come. What I do is insert a resistor between the Yellow wire and ground of 4.7k.

So in order to do this mod. You have to ether do it at the mic connector end or convert your mics to three pin mini xlr and then build a little project box with the switch that I suggested. It is the only way to do this modification since I am the one that came up with it I know its the only way it can be done. I have in the past built it into my st9100 preamp with a little micro switch to bypass this mod so it can be run with out it. But its very hard to do because there is not a lot of room left inside my preamp to begin with.

[Carrera2]

I have no idea what the pic means, but I sense that this illustrates part of the problem.  Anybody explain what I am seeing? This is a frequency analysis made in Audacity of the sample file.  Seems like a lot of bass.

AlanK

[Church-Audio]

I have no idea what the pic means, but I sense that this illustrates part of the problem.  Anybody explain what I am seeing?

AlanK

I dont know what your looking at there it looks like alot of bass to me.. the Church Audio mics you purchased from me do have the mod in them already..

[Alchemy]

I have no idea what the pic means, but I sense that this illustrates part of the problem.  Anybody explain what I am seeing? This is a frequency analysis made in Audacity of the sample file.  Seems like a lot of bass.

AlanK

haha...the frequency analysis shows a lot of bass, but what's your point? +T anyway 

If you put the file into Goldwave and run a high pass filter at 94Hz, it doesn't sound too bad.

[Carrera2]

haha...the frequency analysis shows a lot of bass, but what's your point? +T anyway 

Since it doesn't appear that there is clipping in the sample, I thought that the frequency analysis with bass frequencies at +10db might offer a clue to the problem.  That's my only point.  I don't know enough yet to have another point.

[Church-Audio]

haha...the frequency analysis shows a lot of bass, but what's your point? +T anyway 

Since it doesn't appear that there is clipping in the sample, I thought that the frequency analysis with bass frequencies at +10db might offer a clue to the problem.  That's my only point.  I don't know enough yet to have another point.

Distortion is a tricky little fella its very hard to see at that resolution you have to zoom into the wave to see it properly

[Alchemy]

haha...the frequency analysis shows a lot of bass, but what's your point? +T anyway 

Since it doesn't appear that there is clipping in the sample, I thought that the frequency analysis with bass frequencies at +10db might offer a clue to the problem.  That's my only point.  I don't know enough yet to have another point.

OK, I don't think the frequency analysis could offer too much information that would point to distortion. It was nice to see it anyway- I've only used the FA to look for signs of lossy sources when trading...it's a sheer give-away when you look at an mp3 with one of those and see the drop-off at 16000 Hz.