A few months ago I got myself an Earthworks dm20 condenser instrument mic (generally used for drums (snare and toms)) and issues I had with it were that it had such a hot signal that QU16’s preamp could not handle. At least not with the max -5db it has on gain control. Long story short, I (kind of) solved that situation with a preamp and/or attenuator in between the mic and the qu16.
Now, I am in market for getting myself at least a condenser hihat mic or a pair of overhead mics. Currently the overheads I am using are Audix Adx51s. So, let’s say I narrowed down my choices for a hihat mic (or a new pair of overheads) to Shure sm81 and Shure ksm137.
The first question, if the music that is being played/recorded is louder rock/metal, can I expect both of these mics to perform ok with the qu16, and without needing to go for additional attenuation, like I had to do with the Earthworks dm20?
Second, I suppose many of you sound guys have had experience with the above mentioned sm81 and ksm137. What could be the overall best choice between these two for a hihat and overheads?
My idea was to first go for a pair for overheads and use the audix adx51 I already have for the hihat. But the more I watched reviews on yt, I figured that Adx51s are actually a good choice for overheads.
Then again, I just might go for a pair of shures and mix all four for hihat and overheads. In any case, I guess you see what my dilemma is, but the dealbraker would definitely be the first thing I mentioned in this post - any of the mics being too hot for the qu16. I don’t want that
So, yeah, I’d appreciate your thoughts here. Thanks
I don’t have experience with these mics, so I can’t answer your question directly. However, there are a number of XLR attenuator adapters that you can use inline to reduce a mic signal by 10 to 20 dB, some with switchable levels of attenuatio0n. This should solve your problem fairly inexpensively - $11 to $40.
Do you know anyone who has one of the Allen Heath stage boxes you could try with your QU16?
The stage box inputs have a 20db pad as part of the pre-amp, there is three versions of stage box, an 8 , 16 and 24 channel. Any of those work as a test.
If the stage box works with the mics while an added expense one maybe handy to have
for your set up.
QU16 here but only have used it on fairly lite hitter kits, ribbon and dynamic mics though. I was curious so did some poking around to see if 'pads on drums came up, saw you had an earlier thread as well.
I thought the DM20 might be like their QTC-1 -which can put out damn near line level anywhere near a drum, but this is not the case. The KSM (fairly typical for condensers) is actually hotter than the DM, but then provides a pad. https://earthworksaudio.com/wp-content/uploads/2019/02/DM20-Data-Sheet-2019.pdf
This one might be work asking at prosound web. Several QU users there I believe.
Update:
I did some recording yesterday and ended up removing the shure attenuator. I (again) used my analog mixer, the zedfx, as sort of an attenuator for the snare mic, as that mixer’s gain goes -10db, and then routed that signal into the qu16 with its -5db. Not only there was no hot signal to get in the way of recording, but it (wave) also had a normal .wav shape when I magnified it in the software.
Now, this leads me to believe that the shure pad/attenuator I have is not working properly or it simply can’t handle the dm20.
What do you guys think?
The Zed in the path lets any amount of reduced level sent to the QU. So, unknown.
Assuming here you used the TRS line level input on the QU? (pads another 10dB.
The Shure pad would be easy to test. Some constant repeatable source, with the inline pad, and without it in the path. (if it is the one with three settings? Should see four steps in level.
Maybe try using an external phantom power supply (one that delivers a true 48 volts) and then use an XLR to 1/4 inch TRS plug to connect to the mixers line in jack.
It is so strange (at least for me) the 3 step attenuation on the shure. It’s like it does reduce the signal by 15,20,25db, but it also does not prevent the signal to be too hot. I don’t know how else to explain this. Imagine that I’m recording and without the attenuator, the wave form is all over the screen and distorted because it is being too hot. When I introduce the shure att. it reduces the signal volume by, you name it 15,20 or 25db,but the waveform is still overloaded, too hot, as if I attached the attenuator between the qu and the computer, and not between the mic and the qu.
Is it possible the sound pressure is actually causing the mic diaphragm to reach its physical limit. If the diaphragm itself is distorting, no signal attenuation will fix it.
Have you measured the SPL level of your instrument when you play?
Short term peak with a really good device not a cheap handheld.
seems strange you are the only one I know with that mike that is to loud.
of course other folks do use the attenuators but they do not have the problems you claim to encounter.
What is the spec on max SPL from your mike’s manual?
If it is that hot why couldn’t you go straight to the line input.
With some sort of impedance matching transformer device if needed.
8mv/pa for a snare mic is very hot. My opinion buy a external phantom power an connect the mike to line input. This mic is designed more for studio then live.
Let’s remove “playing hard out of the equation”.
This is from yesterday:
I am the first guy in the video. As you can see I am not bashing the drums too hard, but without some sort of pad the dm20 would send too hot of a signal for qu16 to handle. Zed12fx,though, handles it at -10db.
In any case, what do you guys think about the attenuator that behaves as if it was on the path bewteen the qu16 and computer and not between the mic and the qu16?
Maybe and this is guess but again maybe the phantom power supplied to the QU mic inputs
can not delivered the current needed to operate the DM20 mic.
Looking at spec for the DM20, a Shure SM81 and an Audio 4050 the speced phantom power
current draw is…
10ma for the DM20 voltage range 24 to 48 volt
1.2ma for the SM81 voltage range 11 to 52 volt
4.2ma for the AT 4050 only speced 48 volt with no voltage range listed
I could not find the phantom power current spec for the either the QU or Zed mixers.
Most phantom power supplies on audio mixers is coupled to XLR pins 2 & 3 using 6.8k current limiting resistors so that is getting you into the 10ma power limit range at 48 volt.
Again maybe the voltage drop through the resistors is getting low enough that the DM20 internal preamp is starting to distort.
You could check the mic line voltage with the DM20 connected by opening up the XLR connector on one end or the other of the mic cable and measure the voltage across pin 1 and pin 2 and then across pin 1 and pin 3.
Turn the gain down on that mic channel and mute it as well so you don’t get any pops in the system.
Maybe even play the kit and see if there is a change with high level audio input at the mic.
