Strange Waveform from MXL Drum Cube Pro

[RawDepth]

I grabbed one of the MXL Drum Cube Pro mics while they were on the stupid deal of the day. It works, but it causes some weird low frequency waveform even when no sound is being recorded.

It had plenty of signal and needed no preamp gain at all. (In fact, I had to pad it when recording snare drum. Furthermore, the recorded snare track has terrible DC offset. Other mics on the same channel of the same interface have no DC offset.)

I recorded this 10 second track in a silent room. It is apparently just the "self noise" from the mic. On playback it makes no sound at all. The track sounds silent.

The numbers across the bottom are half-second marks. The dB scale along the right side has been zoomed in a bit.

 

[moresound]

The cube (Non-pro model - original) that I purchased works perfectly with no artifacts.

Maybe you just have to open it up and let the magic smoke out of it?

 

[RawDepth]

Actually, I am considering opening it up. (It's not worth returning a $50 junk mic anyway.) I am thinking that the phantom power must be shorting out somewhere inside. Perhaps it will be a simple fix. (?)

 

[moresound]

Possibly, possibly.

 

[c7sus]

That's the MXL "sound".

 

[RawDepth]

Upon opening the mic, I cannot see anything obviously wrong inside such as shorts or damage. As I said, the mic seems to work fine with the exception of its terrible DC offset. Or, what I thought was DC offset...

I went back and took a closer look at the waveform. This is what I see. (This is a single snare hit, zoomed in.) It seems as though the element in the capsule is unable to move freely in both directions. Though, I don't see anything restricting it.

Has anyone seen a waveform like this before?

 

[moresound]

Upon opening the mic, I cannot see anything obviously wrong inside such as shorts or damage. As I said, the mic seems to work fine with the exception of its terrible DC offset. Or, what I thought was DC offset...

I went back and took a closer look at the waveform. This is what I see. (This is a single snare hit, zoomed in.) It seems as though the element in the capsule is unable to move freely in both directions. Though, I don't see anything restricting it.

Has anyone seen a waveform like this before?

I haven't opened a cube before ... is the capsule a center termination type?

 

[RawDepth]

I haven't opened a cube before ... is the capsule a center termination type?

Yes, it is. Here is a pic.

The diaphragm is a bit off center. Do you think that matters?

 

[moresound]

Off center how?

 

[RawDepth]

Off center how?

Well, the brownish plastic disc which covers the holes is off center. Excuse my ignorance but, I don't know what it does. Is that the actual diaphragm or is that just some kind of dust cover?

 

[moresound]

That does look a bit weird. Not so much being a tad off center as much as being see through.

I'll take mine apart in the next day or so to look at mine and get back to ya.

 

[moresound]

Mind you mine is the *original Cube* not the *Drum Cube*.

 

[gswitz]

I had the same problem with a Guitar Cube Pro by MXL. For me the distorted wave form starts around 80-90 dB.

What causes wave to be flattened above zero only?

I have a problem that recurs | Cakewalk Forums

I want to add that I contacted Marshall and a Rep there advised that this is not proper behavior and that I should use the warranty to send the Mic back and get it repaired/replaced. The Mic comes with a three year warranty.