Soliloqueen's k87(k67) and k47 capsules

[kingkorg]

M7 was meant to be as flat as possible.

Quote from Thiersch:
As a matter of principle we make an effort to achieve a nearly linear horizontal frequency response for both versions [of M7 capsules] in the range 40-15000 Hz primarily in pattern cardioid. For measurement we install our sound transducer STW7 in a little reflective housing. We use the Neumann U67 housing. Using STW7 together with the lollipop M7 housing causes that the frequency response of STW7 is less linear but equates to the characteristic frequency response of Neumann M7.

https://www.thiersch-mic.de/en/estm_faq1.html

 

[Whoops]

The whole area where i test mics is emi shielded

I got highly disappointed now as I thought you had a simple solution for this situation that I didn’t know.
Unfortunately complete EMI shielding is out of my reach.

It’s a bummer when I’m fixing LDC condenser mics, always need to have the headbasket on

 

[kingkorg]

I got highly disappointed now has I thought you had a simple solution for this situation that I didn’t know.
Unfortunately complete EMI shielding is out of my reach.

It’s a bummer when I’m fixing LDC condenser mics, always need to have the headbasket on

You don't have to shield the whole room, just avoid small dimension shield like headbasket. Small dimension shield will almost always affect the high frequencies. You can go with something like mesh paper basket, just make sure the bottom is transparent as well, something like this but with mesh bottom.

https://www.ikea.com/gb/en/p/droenjoens-wastepaper-basket-white-60460107/
Or emi shield curtain.
https://www.fruugonorge.com/wifi-em...9020?language=en&ac=ProductCasterAPI&asc=pmax
Turning off all the 50hz hum sources like transformers and led lights helps as well. I turn off my soldering station and lights when i measure.

 

[Whoops]

Thanks mate,
great info

 

[kingkorg]

Hah! I remember a few months ago you were saying "I am not sure the pattern difference is huge." It IS huge, but it's not huge in a bad way.

Your is definitely one notch towards cardioid, hence the lower midrange bump and better 180° rejection. However it is still hypercardioid as the original, just tiny bit less so.

 

[ElSmurf]

You can go with something like mesh paper basket, just make sure the bottom is transparent as well, something like this but with mesh bottom.

I thought my Ikea repurposing skills were top notch but that is next level. Thanks for all the work you do!

 

[kingkorg]

Interesting: I didn't expect that might higher frequency lift (2k to 5k) in the original as compared to what I heard amongst some originals.

These are A/B swapped into the exact same.mike?

Here's published m147 graph (red) aligned with my measurement. Difference in the very high end can be production variance, headbasket or slight difference in calibration mic used. Of course, many have reported large deviation in Neumanns k47 production over the years.

 

[Quantum J Audio]

Not sure what you mean by this. What i write is my own opinion, and i explained in detail in my first post of the thread why i like this capsule just the way it is compared to the original. There are many monkeys around that like to listen and share their opinion, this monkey here is the only one that shares measurements taken under controlled conditions so average DIYer can easily see what the difference is. Cheers.

If you had quoted all of my post it may have made more sense to you.

My very valid point is that measurements are measurements and listening is listening and sometimes on paper something that looks technically better does not always equal a desirable sonic improvement.

I said no capsule is wrong! It also depends on if you are trying to clone a mic or design a new one.

You have said people only use a FET47 mic in a certain way because they are just doing what everyone else is doing.

In my experience that is simply not true and I am countering that argument and pointing out that the flatter mid range you think makes the flat capsule better is the very reason why engineers and producers love the slightly hyped mid range on an on bass and kick drum.

The reason I want to make the counter opinion is so people without experience of a K47 capsule can have a balanced view of real world use and why a hyped mid can actually be very desirable in two specific recording scenarios.

 

[soliloqueen]

would not use the flat k47 on bass or kick drum. it's too flat, especially <100hz. The extension is way too far. the graph doesn't show that the k47 rolls off below 50hz. the flat k47 is more airtight and becomes omni below 50hz and is flat down to about 0.5hz (settling time ~2s). I plan to play with venting in the next revision to see if I can keep the tuning and roll off the low end a bit.

 

[kingkorg]

If you had quoted all of my post it may have made more sense to you.

So if i don't quote all of the sentences it means i haven't read them? I quoted the part i didn't understand. At this point it doesn't matter i feel you just perpetuate the argument for no apparent reason.

My very valid point is that measurements are measurements and listening is listening and sometimes on paper something that looks technically better does not always equal a desirable sonic improvement.

So you think i made the measurement of this capsule and started using it in my favorite k47 based mic without listening to it? Have you even read any of my posts in this thread? Or are you just irritated that i dare to question the quality of untouchable Neumann, or use empiric measurements instead of adjectives?

You have said people only use a FET47 mic in a certain way because they are just doing what everyone else is doing.

In my experience that is simply not true and I am countering that argument and pointing out that the flatter mid range you think makes the flat capsule better is the very reason why engineers and producers love the slightly hyped mid range on an on bass and kick drum.

I use equalizer for this purpose. And if you take a look into the circuitry of 47fet, it could become obvious why i stated i would never use it on a kick drum. I have also double checked with my own ears.

THIS IS ALL MY OWN OPPINION, I AM NOT APOLOGISING FOR HAVING ONE!

would not use the flat k47 on bass or kick drum. it's too flat, especially <100hz. The extension is way too far. the graph doesn't show that the k47 rolls off below 50hz. the flat k47 is more airtight and becomes omni below 50hz and is flat down to about 0.5hz (settling time ~2s). I plan to play with venting in the next revision to see if I can keep the tuning and roll off the low end a bit.

I would still use it for this purpose, because of the better bleed rejection than the original. I would however address the low end "issue" in the circuit. Just as i would address the lack of headroom and low end THD issue of 47fet electronics.
EDIT:
I guess i wouldn't due to following post and aspect i wasn't aware of.

 

[soliloqueen]

I would still use it for this purpose, because of the better bleed rejection than the original. I would however address the low end "issue" in the circuit. Just as i would address the lack of headroom and low end THD issue of 47fet electronics.

No, you really wouldn't. the flat k47 is so sensitive in the bass that the diaphragm can hit max travel in front of a kick drum.

 

[kingkorg]

No, you really wouldn't. the flat k47 is so sensitive in the bass that the diaphragm can hit max travel in front of a kick drum.

What about that story about the door and vacuum in a recording space?

 

[soliloqueen]

What about that story about the door and vacuum in a recording space?

I had a fully sealed door to a booth once (not common in real recording studios) and opening the door too quickly did indeed pull the diaphragm into max travel. This didn't happen to the regular K47 next to it, because that has a hole in the rear diaphragm to prevent this. In 99% of circumstances this is not a problem but I definitely would not expose it to large single burst or very low frequency pressure waves If you're expecting clean audio. It's not designed for that. That's not a knock against it, it just really isn't designed for that. It's something I intend to fix in the next batch.

Edit:
Just to clarify, the capsule is not at risk of damage from this. It just sounds bad.

 

[kingkorg]

I had a fully sealed door to a booth once (not common in real recording studios) and opening the door too quickly did indeed pull the diaphragm into max travel. This didn't happen to the regular K47 next to it, because that has a hole in the rear diaphragm to prevent this. In 99% of circumstances this is not a problem but I definitely would not expose it to large single burst or very low frequency pressure waves If you're expecting clean audio. It's not designed for that. That's not a knock against it, it just really isn't designed for that. It's something I intend to fix in the next batch.

Edit:
Just to clarify, the capsule is not at risk of damage from this. It just sounds bad.

Just a tip in case you haven't already figured it on your own, it's better to leave gaps in diaphragm spacer than poking holes in diaphragms. Another thing i can't wrap my head around when it comes to Neumann's originals.

Also, in case you forgot, the flat k47 i got from you got a hole in the diaphragm. As a part of the r&d. LoL!

 

[soliloqueen]

Just a tip in case you haven't already figured it on your own, it's better to leave gaps in diaphragm spacer than poking holes in diaphragms. Another thing i can't wrap my head around when it comes to Neumann's originals.

Oh I know, thanks. The originals don't use spacers, so I don't think they had a choice. Maybe that or for the ones that did have spacers they thought it would bow the diaphragm down

 

[Quantum J Audio]

So if i don't quote all of the sentences it means i haven't read them? I quoted the part i didn't understand. At this point it doesn't matter i feel you just perpetuate the argument for no apparent reason.

So you think i made the measurement of this capsule and started using it in my favorite k47 based mic without listening to it? Have you even read any of my posts in this thread? Or are you just irritated that i dare to question the quality of untouchable Neumann, or use empiric measurements instead of adjectives?

I use equalizer for this purpose. And if you take a look into the circuitry of 47fet, it could become obvious why i stated i would never use it on a kick drum. I have also double checked with my own ears.

THIS IS ALL MY OWN OPPINION, I AM NOT APOLOGISING FOR HAVING ONE!


I would still use it for this purpose, because of the better bleed rejection than the original. I would however address the low end "issue" in the circuit. Just as i would address the lack of headroom and low end THD issue of 47fet electronics.
EDIT:
I guess i wouldn't due to following post and aspect i wasn't aware of.

I didn't ask for an apology I am merely stating a different and valid opinion. I've read all the posts on this thread a few times because I have an interest in having a mic than can faithfully reproduce a FET47 sound.

Just because we have different schools of thoughts doesn't mean I disrespect your opinion, but I'm not going to bow down to you and agree.

It's clear you have superior technical knowledge. That does not mean your graphs make my opinion less valid. Surely we can both have a different points of view without being angry about it? If we all agreed on how things should sound records would be really boring.

This is not about Neumann being untouchable for me. It is about a K47 in a FET47 doing a particular job very well. A job that in over 22 years of commercial experience I have not found another mic that when you lift up the fader you are good to go 90% of the time without additional EQ.

 

[soliloqueen]

Sometimes a microphone is just fun

 

[kingkorg]

I didn't ask for an apology I am merely stating a different and valid opinion. I've read all the posts on this thread a few times because I have an interest in having a mic than can faithfully reproduce a FET47 sound.

Just because we have different schools of thoughts doesn't mean I disrespect your opinion, but I'm not going to bow down to you and agree.

It's clear you have superior technical knowledge. That does not mean your graphs make my opinion less valid. Surely we can both have a different points of view without being angry about it? If we all agreed on how things should sound records would be really boring.

This is not about Neumann being untouchable for me. It is about a K47 in a FET47 doing a particular job very well. A job that in over 22 years of commercial experience I have not found another mic that when you lift up the fader you are good to go 90% of the time without additional EQ.

Get it now, thanks for the explanation

 

[Tim Campbell]

About venting in a capsule. The easiest thing to try is what Neumann did on the M7. If you examine an old M7 under a microscope you will see that Neumann for certain years poked a small hole in the edge of the diaphram after the gold stopped and before the glued edge with a pin. This would only be practical on a capsule you want to sacrifice as it means there is easier chance for contamination and shorting.

 

[soliloqueen]

About venting in a capsule. The easiest thing to try is what Neumann did on the M7. If you examine an old M7 under a microscope you will see that Neumann for certain years poked a small hole in the edge of the diaphram after the gold stopped and before the glued edge with a pin. This would only be practical on a capsule you want to sacrifice as it means there is easier chance for contamination and shorting.

I've got a newer K87 with one, two of them actually, whereas the k67 has the vent between the plates in the oldest sample I've taken apart (mid '60s). Seems like they didn't cut the vent into the center spacer If it's not foil. Granted, I haven't seen nearly enough of them to be making broad generalizations but if that's true I wonder why. Concerns about preserving the isolation? Maybe they thought the plastic was too squishy to have a chunk out of it? I'd be interested in seeing how they do it in brand new ones