Jump to content
Herbert Verdino

Schoeps CMR vs. DPA MMP-G

Recommended Posts

Hi, 

did any one do a comparison of this two?

In both solutions it is possible to connect a normal mic capsule from Schöps or DPA to a wireless body transmitter.

On the Schöps page is written, that you have only 60% of the normal dynamic range, using the CMR, which concerns me a bit?

Does the same go for the MMP-G...?

 

 

 

Share this post


Link to post
Share on other sites

ive not used the Schoeps version. but have 4 of the DPA MMP-G
looking at the specs, as long as your radio mic will provide 5v, you have 122dB max SPL.

but Schoeps and DPA use different powering methods for their mics - the DPA are electret mics, which i suspect helps get around the limitation Schoeps have found with the CMR accessory.

Share this post


Link to post
Share on other sites

well... on the Schoeps site is the following written:

 

Sensitivity

ca. 0.6 times the value as measured with a standard CMC microphone amplifier. For example with the MK 4 cardioid, the sensitivity is about 8 mV/Pa, the maximum sound pressure is 130 dB SPL and the equivalent input noise is 29 dB CCIR or 18 dB A-weighted.

 

....and here are the normal values from a MK 4 capsule:

Frequency range 40 Hz - 20 kHz 
Sensitivity 13 mV/Pa 
Equivalent noise level (A-weighted) 15 dB-A 
Equivalent noise level (CCIR) 24 dB 
Signal-to-noise ratio (A-weighted) 79 dB-A 
Maximum sound pressure level at 0.5% THD 132 dB-SPL 
Length 22 mm 
Diameter 20 mm

 

 

 

So my question now is, how this value changes have impact in real live location recording. Since I want to buy such a solution, maybe it is better to go for a DPA, which are electret mic's and are better suited for low voltage?

 

I use Lectrosonics transmitters, by the way.

 

 

 

Share this post


Link to post
Share on other sites
16 minutes ago, Herbert Verdino said:

...

So my question now is, how this value changes have impact in real live location recording.

...

 

It's about a 5dB difference in dynamic range.  Do you often push the limits of dynamic range?

Share this post


Link to post
Share on other sites

sensitivity is 60%, not dynamic range

they are 4 dB less sensitive than a CMC-powered cap due to slightly reduced polarization voltage (ive been told 40V, but ive also been told by schoeps that output level varies with input voltage, presuambly this might affect polarization voltage). Ive always run mine from 7-10V just in case.

Share this post


Link to post
Share on other sites

also worth noting that not all packs put out the full 5V the DPA requires.

 

for example servo input on the lectrosonics SPDR can put out 0, 2V or 4V on a 2-wire bias power, which is lower than spec for the 5V DPA microdot-powered mics require (why many people favor 3V 4063s with the lectros). i have tested myself that 4061s had about 6dB less headroom (due to higher noise floor) when powered by servo input at 4V vs 5V

 

the lectrosonics dedicated 5V rail (used for the 3rd wire in a CMR) puts out only 3.95-4.05V under load, at least on the SPDR i tested (they say servo input is identical between all units but the SPDR has 2 channels pulling 1mA each so maybe the voltage sag is greater?). This 4V power is running the CMR at its absolute minimum spec (lowest headroom), but it should be within the spec, im guessing that powering at 4V corresponds to the specified "0.6 normal senstivity of CMC6 amplifier" (4.5 dB confirmed by new cmr specs listed here:https://schoeps.de/en/products/colette/microphone-amplifiers/cmr.html  and also this handy mv to dbV calculator here: http://www.sengpielaudio.com/calculator-db-volt.htm .

 

Also looking at that new schoeps link they offer different mV/dbV output based on input impedance of your transmitter, they run 4dB hotter into 20kohm vs 2kohm impedance. For this reason when i used the CMR with lectrosonics i went into the line-in circuit, which has higher impedance. the gain stage inside the pack is probably the same regardless of mic or line in, and with the line in you are getting a hotter signal from the CMR and applying less of a gain stage (even though your gain setting is set physically higher on the unit)

 

 

so its difficult to compare dpa vs schoeps specs on an apples-to-apples basis because its not measured with *your* particular equipment and its voltage and impedance. We know CMR headroom can be improved by running it at 10V with a separate power supply (simple 9V battery box). I'm not as clear on how much can be gained by stepping up DPAs from 5V to 9V or so. ive read with the 4060 series that they gain nothing over 7V, the new MMP-G series has not been tested in this manner as far as im aware. i am getting some MMP-G next week and will compare them with the other solutions. I have an MMP-E preamp that apparently has the same sensitivity as the A and C preamps (10 mV/Pa, which you'll notice is right between the MK4 on a CMR and CMC6). However, this is *nominal* sensitivity, and dependent on the capsule. I have 2 MMC4011 caps from 2017, one is 8 mV/Pa, the other is over 11 mV/Pa, both are within spec, that is from the factory calibration certificates. so right there is 3 dB different between them in output, despite the certs listing identical noise floors of 19 dBA

 

 

 

Share this post


Link to post
Share on other sites
4 hours ago, JFtaper said:

also worth noting that not all packs put out the full 5V the DPA requires.

 

for example servo input on the lectrosonics SPDR can put out 0, 2V or 4V on a 2-wire bias power, which is lower than spec for the 5V DPA microdot-powered mics require (why many people favor 3V 4063s with the lectros).

Actually, the Lectros typically have a higher voltage under lavaliere load than all the other "5 Volt" transmitters since the 4 Volt rail is regulated to a constant 4 Volts at the mic under load where the others will drop at the mic under the load. That's what the "servo" name means. Also, the DPA pulls different amounts of current depending on the internal series resistor that is tied to the 5 Volt rail of typical wireless packs. With a 4k series resistor, the Lectro provides 0.5 mA of current to the DPA, similar to a 4k and 5 Volt Sennheiser pack. However, with a 1k resistor, the Lectro provides 2 mA of current, much higher than all other packs. Basically, the DPA has a constant voltage at the mic of 1.8 to 2 Volts (Fet plus transistor) over a wide range of currents. All other lavalieres (Fet only) are constant current (say 100-200 uA) over a wide range of voltages.

 

In sum, the Lectro's servo input will provide the same or more voltage to regular lavalieres compared to 5 Volt packs and will actually provide more voltage and much more current to mics like the DPA.

Best Regards,

Larry Fisher

Share this post


Link to post
Share on other sites
5 hours ago, LarryF said:

Actually, the Lectros typically have a higher voltage under lavaliere load than all the other "5 Volt" transmitters since the 4 Volt rail is regulated to a constant 4 Volts at the mic under load where the others will drop at the mic under the load. That's what the "servo" name means. Also, the DPA pulls different amounts of current depending on the internal series resistor that is tied to the 5 Volt rail of typical wireless packs. With a 4k series resistor, the Lectro provides 0.5 mA of current to the DPA, similar to a 4k and 5 Volt Sennheiser pack. However, with a 1k resistor, the Lectro provides 2 mA of current, much higher than all other packs. Basically, the DPA has a constant voltage at the mic of 1.8 to 2 Volts (Fet plus transistor) over a wide range of currents. All other lavalieres (Fet only) are constant current (say 100-200 uA) over a wide range of voltages.

 

In sum, the Lectro's servo input will provide the same or more voltage to regular lavalieres compared to 5 Volt packs and will actually provide more voltage and much more current to mics like the DPA.

Best Regards,

Larry Fisher

Larry what is the available current on the dedicated 5V pin? with a 2 mA (1mA x 2 mics) load it dropped to 4V (slightly less than 4V on one channel)

 

also can you clarify which DPA you are talking about? i think you mean 406x but this thread is about the MMP-G

 

thanks

Share this post


Link to post
Share on other sites
On 2/19/2018 at 1:27 AM, rich said:

ive not used the Schoeps version. but have 4 of the DPA MMP-G
looking at the specs, as long as your radio mic will provide 5v, you have 122dB max SPL.

but Schoeps and DPA use different powering methods for their mics - the DPA are electret mics, which i suspect helps get around the limitation SChoeps have found with the CMR accessory.

not sure where that 122dB max spl came from,  i dont see a max spl listed for MMP-G perhaps that was a typo as 122 dB is the dynamic range spec.... or maybe they used to publish the spec and updated it

 

max SPL would be dependent on capsule  but preamp also plays a role. For example a MMC4011 cap clips at 159 dB on an A preamp, 152 dB on a C preamp, and 144 dB on an E preamp. the G is probably closer to the E although it has a lower dynamic range (122 for the G vs 131 for the E). just a guess comparing these that a MMC4011 on an MMP-G would clip in the upper 130s

Share this post


Link to post
Share on other sites
5 hours ago, JFtaper said:

Larry what is the available current on the dedicated 5V pin? with a 2 mA (1mA x 2 mics) load it dropped to 4V (slightly less than 4V on one channel)

 

also can you clarify which DPA you are talking about? i think you mean 406x but this thread is about the MMP-G

 

thanks

Hi J,

Basically it is 5 Volts with a series resistor of 1k. So 5 Volts open circuit and 4 Volts at 1 mA (5 Volts minus current in mA's).

 

I assumed (that word) the MMP-G was similar to the 406x series since it interfaces with wireless packs and works with DPA's microdot accessories. If I assumed wrong, it won't be the first or last time. I did look the preamp up but there wasn't much info that I could find.

Best Regards,

Larry Fisher

p.s. The above is for each input on the SPDR.

Edited by LarryF
added p.s.

Share this post


Link to post
Share on other sites

I have tried the MMP-G on a zaxcom transmitter to connect my 4017 with no luck. Noise floor was very noticeable and not a workable solution. I don't know if this would work with different capsules, or if the problem is the 3V zaxcom output....

 

-emory

Share this post


Link to post
Share on other sites
On 5/8/2019 at 7:20 PM, JFtaper said:

not sure where that 122dB max spl came from,  i dont see a max spl listed for MMP-G perhaps that was a typo as 122 dB is the dynamic range spec.... or maybe they used to publish the spec and updated it

 

 

18 months later, i didnt either.
but then, before hitting submit on this, i searched for the MMP-G on the DPA site and found this

 

https://www.dpamicrophones.com/accessories/mmp-g-modular-active-cable-microdot

then scrolled down a bit to the tech specs, and found it again.

Share this post


Link to post
Share on other sites
On 5/8/2019 at 4:51 PM, Emory Murchison said:

I have tried the MMP-G on a zaxcom transmitter to connect my 4017 with no luck. Noise floor was very noticeable and not a workable solution. I don't know if this would work with different capsules, or if the problem is the 3V zaxcom output....

 

-emory

you might want to try measuring voltage under load. official DPA accessories like d:vice and the DAD6001 phantom>microdot adapter only give ~2.6V when loaded with an MMP-G. running it with a consumer sony handheld that provides 2.4V under load, sound is good, and noise is very very low, around -90 dB down

Share this post


Link to post
Share on other sites

Just read through this thread. Has anyone tried the MMP system with lectro transmitter? This could be very good for car rigs and plants if it works.

Thanks

 

Share this post


Link to post
Share on other sites

I tried to use MMP-G and DAD3056 with Lectrosonics SM transmitter but they sounded very bad.
So I asked DPA support whether can I use this combination in correct, then they said, 
"DAD3056 and Lectrosonic is a low volt system and using this setup with a G amp and 4018 capsule will not work – you simply don’t have enough power. Another adapter will not change the performance. "
It's very sad announcement for me, but I found this thread at that time.
According to Larry's advices, I think it might work correctly if I changed the 4k resistor to 1k one.
How do you think about?
I want any advices before I cut off the Microdot connector to test this.

Share this post


Link to post
Share on other sites

I would like to report the conclusion of my mod.
It works good!
I cut out a microdot connector from MMP-G and attached new TA5 connector with 1K resistor. 
Then I compared the 4018/modded MMP-G/Lectro SM combo with 4018/MMP-C/Lectro HM, the former has a little bit louder noise but enough usable.
By the way, I tested 2K, 0.75K and 0.5K resisters too, but they had terrible noise.

Share this post


Link to post
Share on other sites
On 21 October 2019 at 5:31 PM, Naga said:


I cut out a microdot connector from MMP-G and attached new TA5 connector with 1K resistor. 
 

 

Wow! Going to that much trouble I'm surprised you didn't just (OK more work) make a microdot to TA5 link. But ok, cheers, interesting!

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...