Mics and Preamps.....Guitars and Guitar amps...

[TalismanRich]

Does the sensitivity really have anything to do with the ability of the mic to pick up a differential in sound level? What you are dealing with is how much you need to amplify the signal when it reaches the preamp to reach a set level (say 0 dB). But it really shouldn't change the differential between loud and quiet sounds. Turn down the preamp gain by 15mV and that 23mV/1 Pascal pressure mic should be the same as an 8mV/Pa. That's why they put 10dB pads on a mic. The difference isn't due to the inability of the capsule to react to the pressure change and if it's the same capsule the actual output voltage of the capsule should be exactly the same. It's in the different gain structure of the amplifier circuit in the microphone itself. Unless you are overloading the amplifier circuit (or overloading the preamp down the path) it really shouldn't matter.

You don't set your input level the same for all microphones. Especially within the same type of mic, what you would gain by having a higher mic output voltage would be less preamp induced noise. Of course that also depends on how quiet the microphone's amplifying circuit is. A noisy circuit pumping out lots of volume doesn't help.

Comparing a dynamic vs condenser might change things, as the inertia of a dynamic mic's diaphragm with the coils could be higher than that of a 32mm condenser capsule. I would think that would show up in transient response, and it might mean that below a certain level, a quiet sound may lack the necessary energy to even move the diaphragm. It would be a bit like the difference between moving a 15" woofer cone vs a lightweight tweeter element.

I've seen several studies where they have shown that the idea that a low output dynamic is better for a noisy room is completely wrong once the levels are equalized. If a low output SM7b makes you eat the mic, then the lack of room noise isn't due to the mic, it's due to you being so much closer to the diaphragm that the relative level hitting it is different.

 

[CoolCat]

I think I will. why not? at that price too. C114 is around 13mvpa, that seems to work in this studio/closet/w blankets and pillows. 13 +/- sensitivity tends to work fine with the interface preamps which I like having the option, though I have 5qty outboard preamps for now too.

Coming from your "AKG414 positive" comments...seems the C114 is thumbs up!..., thanks for mentioning it....

 

[CoolCat]

Does the sensitivity really have anything to do with the ability of the mic to pick up a differential in sound level? What you are dealing with is how much you need to amplify the signal when it reaches the preamp to reach a set level (say 0 dB). But it really shouldn't change the differential between loud and quiet sounds. Turn down the preamp gain by 15mV and that 23mV/1 Pascal pressure mic should be the same as an 8mV/Pa. That's why they put 10dB pads on a mic. The difference isn't due to the inability of the capsule to react to the pressure change and if it's the same capsule the actual output voltage of the capsule should be exactly the same. It's in the different gain structure of the amplifier circuit in the microphone itself. Unless you are overloading the amplifier circuit (or overloading the preamp down the path) it really shouldn't matter.

You don't set your input level the same for all microphones. Especially within the same type of mic, what you would gain by having a higher mic output voltage would be less preamp induced noise. Of course that also depends on how quiet the microphone's amplifying circuit is. A noisy circuit pumping out lots of volume doesn't help.

Comparing a dynamic vs condenser might change things, as the inertia of a dynamic mic's diaphragm with the coils could be higher than that of a 32mm condenser capsule. I would think that would show up in transient response, and it might mean that below a certain level, a quiet sound may lack the necessary energy to even move the diaphragm. It would be a bit like the difference between moving a 15" woofer cone vs a lightweight tweeter element.

I think it has more to do with up close, and really up close ... ...in comparison to a mic that can record further away and can "hear" sounds better and captures them. Theres some term called "reach" too. and "hotter" mics.As the KlausNeumann explains its the FET that overloads on higher sensitive circuits (the FET) more easily than a lower sensitive circuit, the trade off is noise level specs vs headroom, something like that. In my dumbed down laymens terms its "hearing" analogy, some mics hear really really well, very sensitive and others dont hear as well, less sensitive.

But getting up too close to the FET circuits , or overloading the higher sense can cause distortion to the FET circuit thats then transferred to the preamp.

Going dynamic seems the most common, but the "in between" middle might be a lower sense LDC?

 

[TalismanRich]

Maybe you can overload an FET, but there are mics that can handle 140 or 150dB. That is VERY loud. We're talking gunshot, or jet engine loud. If your vocals are 140+ dB you're really wailing. The P420 is supposed to be able to handle 155dB, and I'm guessing that is using the 20dB pad.

Mics are rated in mV/Pa. 1 Pascal in air is about 94dB. 155dB would be 1124Pa. In terms of voltages, 20dB is 10x the voltage, if I remember my calculations. 40db is 100x, so 134dB without the pad would be 2.8v which isn't anything outlandish. Conversely, engaging the 20dB pad, would drop the 28mV to about 2.8mV/Pa which is similar to what I get with my Sennheiser e935 dynamic.

I'm sure Klaus is very knowledgeable about the mics, and theoretically, I'm sure he's right, but I wonder how many people actually actually run into overloading the FET. Drum are some of the louder instruments and they are generally in 110 to 120dB range unless you are really hitting hard.

 

[CoolCat]

Its above my head in engineering and all the distortions or overloading, proximity.of the circuits.
"why are there various sensitivities of microphones?"
Tensions of the capsule mylar and the deposition thickness...and age of gunk on the capsule...

Im going to get my SM7b (1.2mvpa) and the P420 (28mvpa) and revisit this, MXL V67G is 15mvpa.

here's Neumann site...

Why Sensitivity Varies:

• High-SPL Applications (Lower Sensitivity): Dynamic microphones have lower sensitivity, making them ideal for loud sound sources (e.g., guitar cabinets, drums) without distorting or overloading the preamplifier.
• Quiet Sound Sources (Higher Sensitivity): Condenser microphones often feature high sensitivity to capture subtle details and quiet sounds (e.g., acoustic instruments, vocals), providing a stronger signal.
• Background Noise Rejection: Low-sensitivity mics are often preferred in untreated rooms or live environments because they require higher SPL to produce a strong signal, inherently picking up less background noise.
• Distance to Source: High-sensitivity shotgun microphones are designed for broadcast and film to maintain a usable signal when the subject is far away.

 

[CoolCat]

You got my interest up and so I plugged in the 28mvpa P420 and the old SM7 1.2mvpa.
Simple test of room noise and the "tone" was different, the more sensitive mic had more high freq, and the meter was moving more...while the SM7 was less responsive in meter movement and less higherfreqs-room noise it seemed to me.

I then adjusted them to be more similar in source gain, using voice to set the gains to match on the Reaper meters.
A simple test was then tapping my hand on my leg and scratching the mouse pad.....the more sensitive mic picked that up more, the SM7 barely heard it.
So it makes sense and aligns to a more sensitive mic will probably "hear" more, more reflections from a wall, more small noises, more higher freq fans in computers and all that.

All of this can be overblown too,imo. Recording a song with drums and bass, alot of this noise probably isn't an issue at all.
As you mentioned the SPL, I got up very close to the P420 and didn't hear a FET distorting in normal singing voice. I wouldn't ever be that close anyway.
Maybe a heavy metal screamer might distort a FET input?

I can imagine a 8mvpa LDC vs a 28mvpa will be even less noticeable, both same size capsule, similar capsules...
In a silent recording like flys having sex or buzzing around , the more sensitive mic will probably pickup more of it.
This is all heard in silence with headphones on too. If the drummer starts playing and the bass player joins in, the flys buzzing and someone scratching a mouse pad, probably isnt an issue. ...but then again in a bad room a more sensitive mic will logically pick up more drywall reflections and bad sounds like a PC fan noise.

 

[Papanate]

You got my interest up and so I plugged in the 28mvpa P420 and the old SM7 1.2mvpa.

Why are you referring to the mics by their voltages? Also I’ve not heard of mvpa unless you are meaning mV/Pa?

 

[CoolCat]

TalismanRich and I kind of kicking around sensitivity of mics and the noise floors and things that make noise being picked up.. more or less.

Yes I got lazy typing.. and mvpa = mV/Pa.

It was good and made me get the dust off my vintage SM7 and compare to some other mics again.
I just confirmed again, all that is and has been known for decades.
I did drift off on comparing the interface preamps to my most "pro" preamp and there wasn't much difference heard, for the record. Nothing new there.

Im still confused on all the scales used in Audio. Seems there's so many?
According to my Smart Phone App for measuring my room noise is 20-30 dbA db meter when things are really quiet, and the Reaper mix meter shows -75 dbfs? I think...its dbfs
and -64 dbfs....-90dbfs on Reaper when its all muted. Its a lot of Math and Physics going on, weighted, DB, or DBFS or mV/Pa and all the other terms.
Seems reading the internet -65~-70 dbfs is decent for a HR room. ? NR 10-15 is NC 10-15 or is 30-35 db SPL..etc etc...and Reaper shows dbFS?...

 

[TalismanRich]

I just spent an hour or so playing with my P420 and my e935. Interesting results!

The setup was to put the two mics about 10ft from my monitors (JBL 805s). I set the level using an online tone generator to put out 440Hz at 80dB. I then set the pad on the AKG to -20, fired up the recording and set the levels as close as I could with the relatively crude adjustments on the interface. The AKG was at about 2:30 and the Senn was at 3:00, so they were fairly close.

I recorded the room noise which was about 44dB since the AC fan is running. I then recorded a 440Hz and 1kHz (the generator didn't put out the same level) so that I could compare them. Here were the readings (Lufs I):

Sound ___P-420____e935
Room ____-54.6 ____-59.8
440 Hz ___-24.7 ____-24.3
1000Hz___-15.1 ____-13.4
10kHz____-22.4 ____-10.6
WhiteN __-23.9 ____-21.2

The 10K numbers really threw me for a loop, so I took a spectrum of the white noise. The 10K is a real boost in the e935. P-420 on left, e935 on right. The AKG actually looks pretty good. Maybe the 935 being a vocal mic, is depending on the proximity boost to even things out.

Now, the whole reason for doing this was to try to get two different types of mics at approximately the same sensitivity, and compare them for how much noise rejection you might get between them. Is a condenser going to hear quiet sounds better? The -20dB pad should do the same thing as turning down the input level. So, the last bit was while recording some silence at the end, I fiddle with two guitar slides on my desk, not very loudly, just moved them around. I then amplified that section equally so you could get an idea of the background rejection. Each was boosted 35dB. They sound very close in volume. The noise levels are obviously different as are the frequency responses.

First is the P420, next is the e935.

I should probably do a part two where I just use the input gain for the interface to do the same thing as the pad did here. But for now, my observation is that a condenser mic doesn't pick up background noise more than a dynamic if the recording levels are equalized.

 

[TalismanRich]

While I had everything set up, I went ahead an disengaged the pad on the AKG, reset the input levels at 440Hz to be equal, and did the same noise test of rattling the two slides on the desk.

First are the two 440Hz tones, which were within 0.3dB. Next are the room sound and rattles boosted 35dB. It sounds the same as the previous test with the pad engaged. That tells me that the relative sensitivity doesn't affect the ability of a mic to pick up room noise. It does appear the P-420 has more self noise than the e935.

If you change how closely you speak into the mic, that makes a more drastic difference.

BTW, this is the same conclusion that Julian Krause got in one of his tests. Sensitivity wasn't the difference, but the difference in the frequency response was important.

 

[rob aylestone]

The old thing about dynamics being not as good at noise rejection is simply physics - and old physics too! Newton's First Law. Inertia. A dynamic mic is like a reversed loudspeaker. Most of us have at some time prodded speaker cone and with big ones noticed it takes quite a bit of force to move it - despite the soft rubbery surround, it wants to push back against our fingers and little delicate prods hardly move it, while bigger ones do. If you are cavalier enough to prod the diaphragm on the tweeters of monitor speakers, you discover they move (and break) far more easily. Condenser mics have mylar or similar stretched tight and even cleaning a spec off takes real car - they are light, thin and delicate. Sound pressure hitting a dynamic mic has a diaphragm attached to a former, with a coil of wire wrapped around it. A dinky pressure wave hitting it moves it very little. The same wave hitting the thin mylar moves it far easier - no heavy formers or coils to move. As a result, on a bass guitar or kick drum, there is energy a-plenty, and they work fine. The drummer, however, who has just spent a fortune on amazing cymbals to replace his older, heavier, less precision one has all that money invested in tiny fine details when he tickles the edge at just the right angle. The dynamic doesn't even notice them!

 

[CoolCat]

funny way to put it.
I spent pretty much most my surftime on this sensitivity thing because I get it...but I don't get it.
Also ran all my mics sitting around today and tried some preamps , but for the most part.....ok so the room noise actually seems similar on my Reaper "dbfs" (which I don't get all these names and why its not standardized..US and metric is hard enough and tiring)....

so SM7 sits -78 dbfs for example, the P420 high sensitivity sits around -78 dbfs too....both in a clean IC chips preamp...both same time sitting Idle listening to the room.
both low sensitive mic and the higher sensitive mic reading the near same? which makes no sense in some ways.

then when I apply the NoiseOscope Plugin.....they both look similar.....and both drop off a lot when a HPF 100hz is applied.

the more sensitive mic does have a different sound of noise' more higher freq noises, like white noise-ish.
the SM7 nothing.....a lower freq, rumble....

the preamp gain of course is a big difference once I go to actually speaking in the mic and matching to -18dbfs (as some Reaper guru said is great target).

so the AKG P420 gain resides in a nice safe silent 50~60% preamp setting....where the SM7 requires near full blast, and if I do full blast the preamp-adds a lot of noise..so its kept 87%~92% , just below this preamp noise.

and what Rich said , got me to revisit this (and watched about 10 YouTube's), and did the testing myself....the AKG P420, being more sensitive..alot more sensitive....did not
distort up close and it does not really have a worse noise floor....

but as you mentioned Rob, it does as you said clearly, pick up more frequency's in the higher ranges and can be heard but the meters on Reaper don't really show any difference.

* also use a room free smart phone db meter app which works as good as the one at work that cost a good penny. ...and doing the tests at 3am, things are very quiet and room was reading 20db or dba ? or db weighted something... Reaper in dbfs...whatever ...and the mics sensitivity mentioned in DB or mV/pa....

I know one thing, when going into the rabbit hole, for noise- best scenario- I always end up straight wire to my interface IC preamps.
And to keep my GAIN far away from the noise-area of the preamp, LDC 8mv/pa or 28mvpa works well. ...the old SM7 seems fine too if a person is eating the mic.
surprised even the WA47 tube mic was pretty quiet, and its high sensitivity, with 80v capsule bias Ive read.

funny....the dynamics vs the condenser/capacitor designs..... and makes sense some like the 8mvpa better like the old AKG414 and Neuman u87i....versus the more sensitive U87AI and maybe the SurfaceMount- P420 (being shutdown for the new C114 (13mvpa)?......

 

[LazerBeakShiek]

funny....the dynamics vs the condenser/capacitor designs..... and makes sense some like the 8mvpa better like the old AKG414 and Neuman u87i....versus the more sensitive U87AI and maybe the SurfaceMount- P420 (being shutdown for the new C114 (13mvpa)?......

A dynamic will keep a tight pattern like a hyper card or super card. You shouldn't be worrying about room noise, as the keyway in is pencil thin.
Rock n roll does not need that much room air, a LDC could be overkill.

 

[CoolCat]

it is amazing really the dynamic can do so well and are usually top-end at $500 or less.
LDC can capture more range, more subtle silent highs, I think of a orchestra or instruments and percussions, or the extra shimmer of a expensive cymbal of styles of music ..

Rock, Punk, loud, close , banger music - Dynamics

Soft Folk, Orchestra, sensitive classical with silent pieces to super loud, crisp vocals....LDC....various sensitivity ranges 5mv/pa to 35mv/pa...

SDC crisp, tunnel focused, sensitive or not...

Ribbons?

Almost grabbed a AKG C114 but stopped the buy until I watched all the Videos and Reviews, there's a barrage of them, a NEW AKG LINE release....replacing the Old P series..perception dead....(watch for clearance sales?)
the new AKG are very attractive looking, and very attractive in price. The reviews are either paid advertisements or not.
Rob did a very good one, imo, using the different instruments and in a no BS way as always.

but then C114 SurfaceMount- transformerless brand new with case and shockmout...and good reviews..another popped up the WarmAudio 414 for about the same with cinemag and brass capsule rings and then a little more $$$$ an AKG 414 used. then the confusion of all the 414 history and changes....and the same issue with ALL Famous Legacy history mics = a lot of opinions posted.
AKG leaving Austria 2017 was a big move....corporate change businessmen in suits...... and like Shure with nearly everything now copied or exclusive to China made and Mexico becoming the "expensive line"...and USA Shure some used price for those who mentally convinced are the magic ones...never the new ones.
Neumann is all this on steroids pricing.

I've never really tried the AKG story/designs, interesting read. Seem similar to Shure but more anger by moving from Vienna for AKG, than Shure got away with moving their gear to China and some in Mexico. (I predict Shure will be all China in the future for cost savings and Mexico the new US too expensive)

then again I spoke to an importer who says INDIA will be the new China, in lower cost, race to the bottom pricing...who knows? AKG made in India? is that an issue?
Shure SM7b made in INDIA? how does that sound?

 

[CoolCat]

While I had everything set up, I went ahead an disengaged the pad on the AKG, reset the input levels at 440Hz to be equal, and did the same noise test of rattling the two slides on the desk.

First are the two 440Hz tones, which were within 0.3dB. Next are the room sound and rattles boosted 35dB. It sounds the same as the previous test with the pad engaged. That tells me that the relative sensitivity doesn't affect the ability of a mic to pick up room noise. It does appear the P-420 has more self noise than the e935.

If you change how closely you speak into the mic, that makes a more drastic difference.

View attachment 152187


BTW, this is the same conclusion that Julian Krause got in one of his tests. Sensitivity wasn't the difference, but the difference in the frequency response was important.

I think the LDC sensitivity picks up more room in just being itself, more sensitive, more ability of hearing the frequency's or more frequency's.
This might be the definition clarified-better? the Frequency response = sensitivity.

The room and rattling sample in your recording shows a very noticeable difference in frequency's, so the DAW meter I don't think captures this.
The capsule captures more, is more sensitive, and will capture more room reflections, in other words captures more frequency's and maybe amplifys the subtle hi freq more than the dynamic....which on my DAW the meter doesn't show it, but you can hear it.....like someone turning up the Treble knob and sometimes bass knob = LDC sensitive, vs a Dynamic is just less "excitable".....but odd is the DAW meters don't really capture this. Using White Noise makes sense it would show more of a capsule ability than a 440hz tone, both can hear that freq better, where 12khz or 10khz the LDC more sensitivity might get it more, and the dynamic not as much, or toned down a bit...less excitable.
Its funny when a reviewer has an old U87i 8mv/pa and the new U87AI at 28mv/pa and he thought the old one was "broken"... many find the Old U87i low sensitivity mic "warmer" better" less bright, less treble, smoother.....where in my analogy its like having a warmer light bulb= low sensitivity and a super bright white light bulb is high sensitivity.
Which does a person like?

Sensitivity is a spec that's still rattles my brain, I think I get it then I don't, then I run a test and it makes more sense but then Ill get a similar result and none of it makes sense.
I suppose in a designer goal sensitivity in a anechoic chamber vs a sensitive mic that can pickup more-ugly room reflections, some can hear it and some cant, so using Oscilliscopes can show it better than ears?

or is it easier to just call a mic "bright" or dull or warm or whatever?

my mics today
Antelope Audio SOLO- no transformer LDC
WARMUAUDIO 47TUBES- everything that should be noisy but its very very quiet
MXL V67 GOOD has no money value but stands up fine to a U87AI and anything else...but per price it shouldnt
SM7-Dynamics
SM57
SM58
SM48

AA SDC

new AKG P420....high sense....and built amazing and close to U87ai....(I might another...as I have the Mod Capacitors here this week to MOD one)
$159 closing out...how low will it go? I admit I like the looks of the new C114 better...is there a mod for it yet? or get a C214 and not mod, or a 314, or a 414 or a 414 XL or ULS or XLS or etc...etc..

PreAmps....cleanest with less cables, is the interface preamps here...so for noise testing usually thats the way.
Convertors ...my new Antelope 192khz64bit etc...doesn't really sound any different than my 2009-chip and convertors interface on Playback to my ears...Julians test machine would see it maybe.

backorder-> Behinger ADA8200 on order, with Midas Preamps...$179...8 channel IN and 8 XLR out, with ADAT converters...$22 per preamp, I couldn't build one cheaper and as good.

 

[Scott Baxendale]

 

[CoolCat]

Seems the blind tests don't always agree with these type picks, but he's speaking from a actually owned and used it.
Andrews supposedly not-biased, free independent making cash off the streaming and not paid advertisements. Does a good video too. visual and sound.
I chuckled when he said "focusrite...was a real company before , now... we associate the interfaces and Focusrite brand "with our Uncles failed music career"...but "they made great stuff in the day!" by Rupert....etc... "Uncles Failed Music career" is synonymous with Focusrite? really Andrew? lol too funny. sarcasm.

Personally never owned any of his "God list" ....
BAE DMP and all his God Tier are not even full rack versions, only 500 series or box type. except the A design Pacifica- full size channel made God Tier. I've read those are really top shelf. Nice thing about a lot of these "top shelf-excellent " pieces there's a DI too, so its PreAmp and DI. ....I have tried others probably equal to those and didn't hear preamp magic, LA610, Emperical Labs, ISA, ...

Having a great preamp though to compare to the interface preamps is fun to do....ISA One, BAE DMP, UA 710 used $500 to $1000. Singles, you get great piece- dual duty.

I've never done 500 series, always the older 19" rack stuff, never recorded sessions from behind the glass either so...its just gearheads fun.

Any God Tier he left off?

 

[CoolCat]

 

[DrewPeterson7]

but then C114 SurfaceMount- transformerless brand new with case and shockmout...and good reviews..another popped up the WarmAudio 414 for about the same with cinemag and brass capsule rings and then a little more $$$$ an AKG 414 used. then the confusion of all the 414 history and changes....and the same issue with ALL Famous Legacy history mics = a lot of opinions posted.

FWIW, I don't own an original C414, but I own a matched pair of sE4400a's which is their take on a brass capsule C414, and in the Warm Audio Mystery Box sale I ended up getting a WA14, which is their take on a 414. I think you commented in the comparison video I shared.

If you're thinking about one of the budget AKG versions, I'd give strong consideration to the SE. It's a great sounding mic; even the WA14 was really nice sounding too, but I though the SE was the better version, significantly more sensitive and a little fuller, and the slight extra high end sparke in the WA (the transformer, maybe) was something I could match with the tiniest bit of added EQ.

 

[CoolCat]

Drew,
the warm 14 is been on my mind.
the AKG414 XLS Im test driving is cool kit, but verdict out, and several podcasters mentioned really liking that 214 surprisingly which isn't even a traditional capsule and more like a 3000 or something electret but sounds-really good. they repeated..so I wanted to try that one.

still I like Warms goal...to try their Vintage inspired mics, in their Price vs a $$$$$$$$$ AKG414 brass cap with transformer....is not happening for my wallet.

grabbed 214 $200+....414 was $749...but has mint condition kit with it, and papers etc..the P420 Rich mentioned is working for me as is but I might grab another on the clearance, $159 is a nice kit and I have the Mod capacitors.

Probably do a WA14 next for curiosity sake....