DR 40 with external microphone

[brk_]

Hi everybody,

I recently got a Tascam DR 40 and it's a quite interesting unit.
I am very new to Tascam and handheld recorders in general and I have some trouble with my setup.

My setup consists of a

• Tascam DR 40
• Drift Innovation Microphone https://www.amazon.co.uk/Drift-Innovation-External-Microphone-Technology/dp/B00B5R4XWI/
• Jack adapter https://www.av-cables.dk/jack-adapter/high-quality-6-3mm-mono-jack-han-3-5mm-minijack-hun.html

My recording settings are:

• Format: WAV 24bit
• Sample: 48k
• Low cut: 120Hz
• Pre rec: off

Recording mode:

• Rec mode: MONO
• Source: EXT IN 1

I plug the jack adapter into the Tascam and the microphone into the adapter and set it to MIC + phantom but when I record I just get a lot of noise. I have tried to play around with the settings such as the low cut, stereo, mono, mic without phantom etc. and the input levels but I haven't been able to troubleshoot it myself so I was hoping maybe someone here had some experience with a similar setup.

 

[GTBecker]

I suspect the Drift external mic is not suitable for the DR-40.

The mic appears to be an electret. Electrets require power, but one would not do well if powered by 48v phantom power; I wouldn't be surprised if the mic has been destroyed.

Electrets are typically powered by 5v or less. Try plugging the 3.5mm mic plug into the mic input of a laptop or desktop computer and see if you can record; the mic is probably damaged if you can't.

What do you intend to record?

Tom

 

[brk_]

Hi Tom,

Thanks for sharing, I wasn't aware of that.
I tried plugging it into my desktop computer and it still seems to work.

I was planning on recording the sound from my exhaust while moto-vlogging. I plan to switch between a gopro with an external in-helmet mic and the tascam which is placed in the backseat. I am under the impression that with an external mic I'll get better sound quality but maybe the built in mics are similar to the drift external mic?

Do you have any recommendations for a mic of such use as the above?

 

[GTBecker]

> ... recording the sound from my exhaust...

Hmmm. That's a tough environment; 60MPH wind-driven water and road debris, vibration and heat.

My first thought is a piezo coax contact mic (like http://www.ebay.com/itm/Piezo-Cable...Cigar-Box-Guitars-More-50-60-01-/171281088907, dirt cheap) which needs no power, can be sealed to the elements easily and might even survive direct attachment to an exhaust shield (but probably not an open header pipe). The sound that would yield will likely not be what a rider would hear, but for a sound bed under narrated video it might still be suitable. A heavier higher quality piezo cable is also available (https://www.digikey.com/products/en/sensors-transducers/accessories/510?k=1005801). Piezo film exhibits very high impedance which might need some attention (maybe www.ebay.com/itm/Wright-G-2-Terminator-Guitar-Amplifer-Impedance-Matching-Cable-System-/172518845046), or maybe just a Hi-Z/Lo-Z transformer or JFET voltage follower - if you are able to build.

> ... maybe the built in mics are similar to the Drift external mic?

The DR-40 mics are similar to the extent that they are also electrets but they are cardiods - which are more sensitive to wind and buffeting, thus requiring more baffling; the Drift mic is probably an omni element, inherently less sensitive to wind but more sensitive to road and chain noise.

An interesting problem.


Tom

 

[tzdvl]

Your problem using the Drift microphone is not related to phantom power. The problem is that the Drift is an unbalanced microphone.

The DR-40 is just not designed for use with unbalanced or single-ended inputs:

http://tascam.com/product/dr-40/faqs/

If you Google "DR-40" and "unbalanced input" you will see that many others have had problems trying to connect unbalanced mics (and RCA-type line-level sources) to the DR-40, which simply is not designed to accept such inputs.

The adapter you purchased, depending on how it is configured, will result in one of two situations:

If it connects the mono mic's tip to both the tip and ring of the adapter, the DR-40's balanced input will see the same phase signal on both pins 2 and 3, resulting in signal cancellation. You'll hear just noise, with no recorded sound.

If the adapter connects the mic tip to only the tip OR the ring of the adapter, one pin of the DR-40 input will see signal, and the other will see no signal. In this case the mic's signal will be recorded, but at -6dB (half as loud), and possibly with added noise from the un-terminated side of the input.

What you need is some way to convert the mono single-ended (signal and ground) output from the mic to a true balanced signal (+ and - and ground).

A transformer type adapter

https://www.google.com/search?q=unbalanced to balanced transformer&source=lnms&sa=X&ved=0ahUKEwiRvMHxh9fVAhWGxYMKHRxoCuIQ_AUICSgA&biw=1697&bih=925&dpr=1

will work, but will result in the mic's signal being recorded at a -6dB lower level (half its normal volume), which might not be loud enough, even at the DR-40's maximum recording level.

The best solution would be some sort of "active" unbalanced to balanced converter box, but such a device would require a DC power supply (12 volts or more), and would probably be somewhat expensive. I don't even know if such an animal exists for microphones. Maybe someone could make a suggestion?

If it was me, I would just try using the DR-40's built-in mics. I would buy a furry "dead-cat" windscreen

https://www.bhphotovideo.com/c/product/876324-REG/Tascam_WS_11_Windscreen_for_All.html

and try to locate the Tascam somewhere as protected from the wind as possible.

Ain't this stuff FUN?!?

 

[Wekavern]

For outdoor use with movement make or buy a short right angle plug line input cable. Secure with thick rubber band around DR-40 body. This avoids connector bouncing and avoids straight entry connector putting strain on DR body socket and obstructing muff. Best to use muff over foam to maximise wind attenuation.
You are going to have peaking problems for sure and will have to experiment to get the level right. A 20dB attenuator cable might be handy. You must convert any unbalanced mic input to balanced and only record in mono. External add-on small format passive or active device is most convenient. Battery box might be essential for your application as well.
Remember the more connections you have the more connection rattling and more structure-borne vibration likely to cause spikes .
Plug your unused ports with silicone bungs or best put the lot in a simply made neoprene bag closed with velcro strip- sufficient to keep out splashes and dust but enable cable entry.
Hope that helps,

 

[Art Anderson]

Good call by 'tzdvl'. As soon as I followed that link to the adapter and saw the 3 conductor I thought "oh-oh".
DR-40's external pre-amps were intended for mono signal, balanced inputs into those combo jacks, i.e., 3 conductor 1/4" phone plug or by XLR. That said, I connect a very cheap dynamic microphone connected by a 2 conductor 1/4" phone plug into EXT 1 and get a proper signal, but it needs a lot of gain.

As for motorcycles, I'm having challenges too. Mostly it's about the placement of the external microphone(s) and keeping the level from saturating. That's where the DR-40 Dual recording level mode can help put you in the ball park +/- 12dB with less guess work. Once I'm off and riding I don't like to be stopping after half a mile over and over to playback audio and change settings so it's time consuming to find a sweet spot.

The videos I have watched with the least amount of unwanted noise were recorded from a microphone inside the helmet that the rider was using for commentary. They still catch the desired motorcycle noises and without the wind. That has to depend a lot of the helmet's noise isolation I would think.

I tried a lavalier in a few places on my 1100 cc inline 4; for example, wrapped in a sock and placed inside the tailpiece behind the seat. Wickedly good exhaust tone but the level saturated and it was direct to an action camera so I didn't have a clue what the level was until I was done. (Can't attach an MP3 or I'd load it here)
Maybe that cavity was acting like an echo chamber too. Another placement - inside my jacket against my chest - wind noise. Another - internal microphones of the DR-40 which was inside the map pocket of my tank bag so I could monitor and control it - too much wind noise again.

Even though the microphone is enclosed, if what ever is covering it is catching wind noise, that gets picked up loud and clear. You'd be better off having the microphone exposed but surrounded with a "dead cat" fur hood. Don't bother with the foam windscreens. They won't do anything about wind.

 

[Soundie]

Is your Jack Adapter maybe damaged?
I once used a Jack Adapter just like the one you link to, and had troubles with noise too.
Turns out it was damaged, which could not be visually.
I switched to Sweex Jackstick Adapter (Bought at this site), and it has worked perfectly ever since.