Help me to find Better Recording after DIY acoustic treatment

[TalismanRich]

Dave, I'm as surprised as you are at the noise in that track.
Just for fun, I pulled down RightMark and ran a test on my Tascam interface. Mic input was at 50% which is about where most of my condenser mics are set. This was the spectrum.

Cat, I was also thinking that you might be getting noise induced by lighting. If you run CFL or LED lights, some can generate a fair amount of RF noise. I have read about audio gear getting noisy when certain bulbs are used.
Are you using incandescent, CFL or LED lights in your room? Any dimmers? Dimmers can be bad news as well.

 

[TalismanRich]

Yes it helps


>As for the samples without the mic plugged in, they are all basically silent. Noise levels were in the -75dB range with no discernible whine or other sounds. That indicates that you're probably inducing the noise into the microphone itself. Since removing the gadgets also removed the noise, then unless those gadgets are making an audible whine, then they are somehow introducing noise.


Q2. The last two sentences which I marked bold, I'm afraid I couldn't understand, would you please elaborate them?


Thank you once again

There are two ways that noise can get into a system. The first is simple audio, so if a particular device makes a noise and the mic is sensitive enough to hear it, you pick up the noise. You might not even notice it unless you get very close to the device. A spinning hard drive would be one such type of noise. I can hear my external drive when I bring the mic up enough. I have to unplug it.

The other way would be if the device is emitting RF or electromagnetic noise. An example of this is my turntable, a Rega Planar 2. When I tried using a Grado cartridge in that turntable, I would pick up hum from the motor as the arm worked its way towards the center of the record, where the motor was closest. On the other hand, using an Audio Technica cartridge gave no problem.

You could easily test this by setting up your mic and simply moving things closer to the mic. If you hear an increase in buzzing, then that's a possible problem. Either turn off or remove the device from the area.

Good luck.

 

[CatMalone]

There are two ways that noise can get into a system. The first is simple audio, so if a particular device makes a noise and the mic is sensitive enough to hear it, you pick up the noise. You might not even notice it unless you get very close to the device. A spinning hard drive would be one such type of noise. I can hear my external drive when I bring the mic up enough. I have to unplug it.

The other way would be if the device is emitting RF or electromagnetic noise. An example of this is my turntable, a Rega Planar 2. When I tried using a Grado cartridge in that turntable, I would pick up hum from the motor as the arm worked its way towards the center of the record, where the motor was closest. On the other hand, using an Audio Technica cartridge gave no problem.

You could easily test this by setting up your mic and simply moving things closer to the mic. If you hear an increase in buzzing, then that's a possible problem. Either turn off or remove the device from the area.

Good luck.

>Are you using incandescent, CFL or LED lights in your room? Any dimmers?

I do not use incandescent, CFL, dimmers but :

There is a tubelight (not sure whether its led or not, its a Phillips tubelight which is slim and comes with inbuilt batten) in the room which is near ceiling, and I just measured the
room height, its 10 feet and tubelight is approx. 9" from the ceiling and its too far from my system.

I don't use dimmer but there is fan regulator in the room and it remains off.

There are two other lights in the room but they remain switch off.

One thing worth to mention, the first and second day (Jan 20 and Jan 21) when I did the DIY acoustic treatment and did the recording and you found whine in the noise floor both the days I did install a temporary led bulb in extension cord near me because it was dark).

BUT the third day (Jan 22) when I did the testing (there was no DIY acoustic treatment) and also I didn't keep any led bulb around me. It was the same day when I shared Reaper .zip file. On that day only twelfth track had no whine in the noise but in the very next track it came back.

So I guess there is another thing which I need to find out now which is causing issue and I will do this today.


>You could easily test this by setting up your mic and simply moving things closer to the mic. If you hear an increase in buzzing, then that's a possible problem. Either turn off or remove the device from the area.

I will do it today, thank you.




As you said: "Noise levels were in the -75dB range"

Q1. How do you check Noise levels, do you see at Master mixer, I had to often click on top of the bar at master mixer to clear the meter because it stuck at one figure.


[MENTION=89013]TalismanRich[/MENTION] Earlier in this post you nudged me to get the headset so I decided to get them, thank you I started a thread to ask fellow members which one should I get based on the criteria I mentioned there so I request to your share your suggestion there, your opinion matters to me.

 

[Bars Prods]

I agree with Keith that 'with treatment' is better, less room reflections. ALso, for voice work like this, recording at the volume/closeness of your 'with treatment' sample will result in less noise being noticed between phrases.

 

[CatMalone]

Attached is the spectrum of the 'silent' Solo and for comparison that of my Behringer 204HD (at min gain) with nothing plugged in.

The hum on the Solo and its spray of harmonics confirms to some degree a suspicion I have long held about these very basic (aka cheap!) one mic input interfaces? They are not built to the same standard as products further up the price range.

I agree that the hum level is well down but actually gives a noise floor of only -76dB fs peak whereas the 204HD manages -93dBfs peak. I would be rather disappointed to have bought the Solo!

Of course, these tests should be done with properly terminated, 150 Ohm, shielded XLR in place but even so, the picture is not a pretty one.

The good news is, the AI is NOT the source of the whine. Good luck tracking it down! I have a house to prepare for a visitor so will be no help until next Sunday...Sorry.

Dave.

Dave,

>"comparison that of my Behringer 204HD (at min gain) with nothing plugged in."

You used with min volume while testing whereas I had gain at around 65% while silent recording, does it make any difference?



Before buying AI I did some research, checked reviews at youtube and considered the opinion about those who were closed to what I do and found most of the people who do podcast or do audiobooks recommend Scarlett solo. I was actually convinced when some sound engineer and people related to mixing or music recommended Focusrite scarlett, although most of them were using 2i2 or higher model and some of them also said they started with Scarlett and later upgrade to other brand.

I checked my resource folder and found I did consider various models including Behringer U-Phoria UMC204HD, in fact the price of this model and Focusrite Scarlett Solo 2nd gen were almost same at my end. I didn't require multiple inputs so I considered Scarlett solo (because it had red color lol may be) and also there was deal going on so I got that.

More importantly:
One more thing I considered seriously before buying, there was a person named Julian Krause at YT who did compare scarlett noise flloor with other AI's and he did testing at high end level, very accurate (at least I got this impression ) that scarlett 2i2 had -128db EIN









He compared the noise floor difference between UMC204HD: -129.1 dBu and in scarlett 2i2: 128.2 dBu and it was minor
so at that time I checked all the specs of scarlett 2i2 and scarlett solo both were same including: Noise EIN -128dBu (A-weighted) excepts inputs or may be any other minor thing.

I'm attaching an image file which is not available at focusrite site any more:

it say noise floor in solo 2nd gen is: -128 dBu


I guess last year I got AI after watching his video and I considered it was pretty much good entry level AI to start with.

Even I had a good budget at that time to get any interface in fact I also considered audient ID4 but I was assured solo is good (and have Red color ).

I wish I'd have come across you, may be I got a better one.

 

[ecc83]

"You used with min volume while testing whereas I had gain at around 65% while silent recording, does it make any difference?"

It does, a bit. I did the original recording at minimum gain because of course I had no reference to the ampont of gain you used. I also could not be arsed to hunt up more kit at the time!

The attached spectrum for the 204HD was obtained thusly...

204 into i3 HP laptop running Samplirude SE8. Dynamic mic plugged in. Behringer XM8500. Set gain for average level of -20dB fs, mic 2" from cake hole. Unplgged mic, gain left set, ran recording. As you can see the spectrum is remarkably clean barring a blip at 50Hz and that could be because I had the laptop charger plugged in.

The noise floor is a pretty commendable -80dB fs peak. The figures would be some 3-4dB better probably with a screened, terminated XLR plug (got one. 'k knows where atmo)

The noise figures for the Solo's pre amp (just the one!) are entirely believable. They are also easy to achieve these days for analogue circuits (especially for mic pres where the gain is not specified!) but the test of an analogue/digital device is the all up converter noise and there seems to be something amiss with the Solo in that department?

T Rich. Just noticed your spectrum? White on Black. You can invert the colours in RMAA and you need to if you intend to print the graphs otherwise you go through toner like a b'std!

Dave.

 

[CatMalone]

"You used with min volume while testing whereas I had gain at around 65% while silent recording, does it make any difference?"

It does, a bit. I did the original recording at minimum gain because of course I had no reference to the ampont of gain you used. I also could not be arsed to hunt up more kit at the time!

The attached spectrum for the 204HD was obtained thusly...

204 into i3 HP laptop running Samplirude SE8. Dynamic mic plugged in. Behringer XM8500. Set gain for average level of -20dB fs, mic 2" from cake hole. Unplgged mic, gain left set, ran recording. As you can see the spectrum is remarkably clean barring a blip at 50Hz and that could be because I had the laptop charger plugged in.

The noise floor is a pretty commendable -80dB fs peak. The figures would be some 3-4dB better probably with a screened, terminated XLR plug (got one. 'k knows where atmo)

The noise figures for the Solo's pre amp (just the one!) are entirely believable. They are also easy to achieve these days for analogue circuits (especially for mic pres where the gain is not specified!) but the test of an analogue/digital device is the all up converter noise and there seems to be something amiss with the Solo in that department?

T Rich. Just noticed your spectrum? White on Black. You can invert the colours in RMAA and you need to if you intend to print the graphs otherwise you go through toner like a b'std!

Dave.

Dave, I'm afraid, it may seems like there is a slight misunderstanding so Please allow me to clear that:
By reading your last reply it seems either you got the wrong impression of what I replied you or I'm afraid, may be you misunderstood what I said because I might forgot to mention while replying why I shared
that old story (totally my mistake). I make notes whenever I do some research to buy something and in last post I written all that based on old notes which I created (may be) last year. But certainty, I did not mean to say you were wrong in any way. In fact I appreciate you a lot what you did and shared on this post. You taken time to help me to resolve the issue.

Yesterday, I replied to your post (with all due respect), "just to share with you that in which circumstances I bought the solo".

Even though youtube reviews (and that guy Julian) were the prime basis of my decision of buying this solo AI at that time, But still, after reading your replies on this thread and seeing attached spectrums which you provided, I developed 100% faith in whatever you said and after knowing your opinion I got impressed with your in-depth knowledge of Audio and in this stream.

It's all good here that's why at the end of the last post I mentioned "I wish I'd have come across you, may be I got the better one." which means If I had taken your opinion (your advise) before buying AI then I would have got the good AI.

Hope I was able to clear that!

I truly believe you shared the insights in your posts on this thread and I have no doubt it.

Love you and have immense respect for you.

 

[ecc83]

Cat, I did not take anything you said as in the least critical of me. Good Gravy!! In the knock-about world of forum exchanges I have been in NO doubt when someone is having a pop. I am not in the least offended, saw no slight at all (we grow pretty thick skins here or bugger off!)

Indeed! It is often 'I' that has put the odd nose out of joint. I have a rather dry, Limey wit (some would say half of one) and in an international forum one is bound to go wrong sometime.

So, water under, back to the technicals!

You are quite right in saying I would have put you off the purchase of the Solo but not because of the apparent shortcomings in its performance. No, very often newbs
go for these single mic input AIs because they are low cost. The thinking being I suppose "I only have one microphone, there is only me, only need one mic input".

That is true in essence but one mic pre amp precludes the person trying stereo recording in all its varied forms. Even recording a single instrument such as an acoustic guitar, two mics can give a flexibility and extra quality to the sound. Then you might also find a friend!
I did not know the noise issues with the Solo* but am not surprised as I have always suspected these low cost devices must be built at the most basic level?

There ARE single mic input AIs of higher cost and excellent quality but the reasons for their design is to do with other matters than cheapness. Such AIs also very often incorporate an ADAT port so an 8 channel pre amp can be used if needs be.

*We must be very careful NOT to besmirch Focusrite. My setup is basic in the extreme as is yours Cat and there could be all sorts of factors beyond F'rite's control that are causing that poor noise result, a noisy PC supply is one such possiblity. Again however, a more expensive AI might have better filtering and PSU supply rejection. I would love to get data from other Solo users.

Dave.

 

[CatMalone]

Dave, thank you so much. I totally agree with with

------------------------------------

Last night when I was ready to record, I heard a weird noise when I was monitoring (to make sure everything is all set before I hit the record)

It's not a whine in the noise (I guess) so I recorded 30 seconds 'room tone' three times and it sounds like some frequency (or noise) is going up and down (may be it's my illusion

If you increase the volume you'd hear a noise going up and down

1. Recorded before rain:
Dropbox - before-rain.mp3 - Simplify your life


2. Recorded with Laptop's power supply on:
Dropbox - laptop power supply on.mp3 - Simplify your life


3. Recorded when Laptop was running on battery:
Dropbox - laptop without power brick.mp3 - Simplify your life

(I thought may be its due to power supply so I ran laptop on battery)

I recorded all these files at 4:30am

Even though it rained last night but I recorded when rain was stopped so its not the rain noise.

I request you [MENTION=89697]ecc83[/MENTION] [MENTION=89013]TalismanRich[/MENTION] to please have a look at it.

 

[TalismanRich]

I listened to the three files, and there is something definitely modulating and phasing. Were these done with the microphone plugged in and the gain up to normal (it sounds like that is the case). If so, then I wonder if there is an issue with the microphone. Is there some way that you can borrow another one, perhaps a different type and brand?

I tried doing a quick recording with my Rode NT1 into the Tascam, with the gain up about half way. This is slightly above what I would normally do for a vocal. I recorded about 10 seconds of silence. It has none of that phasing or modulating sound. You can hear me take my headphones off and put them on the desk if you crank it up very high. The external hard drive was also running, so you can hear a bit of that in the background noise as well.

Sorry, but I'm at a bit of a loss as to the source of this noise.

 

[ecc83]

I am also at a loss to explain the noise. Can hear a low frequency, low level 'hum' coming and going after I had normalized the clip but with my hearing, little more.

The spectrum does not help a lot but the grab of Samplitude's meter* shows a peak noise floor of around -55dB fs. I have a Dolby B cassette machine better than that!

I can only suggest you get an XLR plug and solder a short* across pins 2 and 3 and reassemble, plug into mic channel and do two runs. One at max gain and one at minimum. The result SHOULD be just more wideband noise for the higher gain track with maybe just the merest, 2-3dB bump at 50Hz and its harmonics.

N.B. The Behringer 204HD has gone with my son and will be in France very soon.

*I use Sam SE8 because the meters read down to -90dB fs and are a nice size.
Cocked up the '*' Should refer to the fact that a short is not optimum and one should use a 150-200 Ohm resistor but not many folks here have my piles of electronic junk!
Dave.

 

[CatMalone]

I listened to the three files, and there is something definitely modulating and phasing. Were these done with the microphone plugged in and the gain up to normal (it sounds like that is the case). If so, then I wonder if there is an issue with the microphone. Is there some way that you can borrow another one, perhaps a different type and brand?

I tried doing a quick recording with my Rode NT1 into the Tascam, with the gain up about half way. This is slightly above what I would normally do for a vocal. I recorded about 10 seconds of silence. It has none of that phasing or modulating sound. You can hear me take my headphones off and put them on the desk if you crank it up very high. The external hard drive was also running, so you can hear a bit of that in the background noise as well.

Sorry, but I'm at a bit of a loss as to the source of this noise.

>Were these done with the microphone plugged in and the gain up to normal (it sounds like that is the case). If so, then I wonder if there is an issue with the microphone. Is there some way that you can borrow another one, perhaps a different type and brand?

Yes, those were done with microphone plugged in. Unfortunately I don't know anyone who has XLR mic or do a similar work which I do. (hmm I'm constantly thinking)

As you said you keep almost 50% gain for condenser mic, I tried this (when you mentioned first time on this thread), at my end the gain couldn't reach to -12db (as I try to keep the gain between -18db to -12db). that's why crank the gain little bit more.


I worked, the whole night and kept trying different ways and most probably I came across the cause of this weird noise issue (or at least I'm close to it) :

I recorded two times 30 seconds: the first one has almost no noise (at least it seems to me) and the second file has the same weird noise

1. Recorded at around 4:30 am - it has no noise:
Dropbox - 1_rec_3am_room-tone_Gain-65%.mp3 - Simplify your life

2. Recorded at around 5 am - it has that same wierd nosie:
Dropbox - 2_rec_4.30am_room-tone_Gain-65%.mp3 - Simplify your life


I'm looking for your input.
I am grateful to you.

 

[CatMalone]

I am also at a loss to explain the noise. Can hear a low frequency, low level 'hum' coming and going after I had normalized the clip but with my hearing, little more.

The spectrum does not help a lot but the grab of Samplitude's meter* shows a peak noise floor of around -55dB fs. I have a Dolby B cassette machine better than that!

I can only suggest you get an XLR plug and solder a short* across pins 2 and 3 and reassemble, plug into mic channel and do two runs. One at max gain and one at minimum. The result SHOULD be just more wideband noise for the higher gain track with maybe just the merest, 2-3dB bump at 50Hz and its harmonics.

N.B. The Behringer 204HD has gone with my son and will be in France very soon.

*I use Sam SE8 because the meters read down to -90dB fs and are a nice size.
Cocked up the '*' Should refer to the fact that a short is not optimum and one should use a 150-200 Ohm resistor but not many folks here have my piles of electronic junk!
Dave.

I liked the big size meter in Sam SE whereas in reaper, the master meter numbers aren't visible properly so I had to find a different theme (which doesn't have all the features) and have to keep the floating meter full size at right side all the time (it eats up a lot of space)



>I can only suggest you get an XLR plug and solder a short* across pins 2 and 3 and reassemble, plug into mic channel and do two runs. One at max gain and one at minimum. The result SHOULD be just more wideband noise for the higher gain track with maybe just the merest, 2-3dB bump at 50Hz and its harmonics.

Cocked up the '*' Should refer to the fact that a short is not optimum and one should use a 150-200 Ohm resistor but not many folks here have my piles of electronic junk!

I tried to find a tutorial about this on youtube but didn't get any reference. Is there any article on internet or tutorial/reference on youtube about this and rest all I'd do it myself (soldering and shorting) and would provide you two recordings as you mentioned?


Q1. Do I need to get Male XLR Connector and after soldering (shorting and attaching 150-200 Ohm resistor) I have to unplug the mic and insert this xlr connector into AI, am I correct!

Q2. Can I buy any male XLR Connector or it must be of good quality? (In case, If I don't get the Male XLR Connector then I'd get the low cost xlr cable and pull the male connector from it, is it ok)? (sometimes its not easy to get things at my end)


Thank you so much.

 

[ecc83]

Yes you need as male XLR but you would either short pins 2 and 3 OR fit a 150 Ohm resistor across them.

Probably the quick and dirty way is to take a cheap cable and chop it about 250mm from the XLR end, strip back and expose the shield but DON'T cut it off. Strip both cores about 20mm and twist to short. Sleeve or tape that and run the shield back over it if you can. Then wrp the whole end in chicken foil. Make sure the shield has not shorted to cores.

You now have a shorted, shielded XLR plug!

Dave.

 

[CatMalone]

Yes you need as male XLR but you would either short pins 2 and 3 OR fit a 150 Ohm resistor across them.

Probably the quick and dirty way is to take a cheap cable and chop it about 250mm from the XLR end, strip back and expose the shield but DON'T cut it off. Strip both cores about 20mm and twist to short. Sleeve or tape that and run the shield back over it if you can. Then wrp the whole end in chicken foil. Make sure the shield has not shorted to cores.

You now have a shorted, shielded XLR plug!

Dave.

Dave, I already placed an order yesterday and will get all these things within 2 days.
Q. I was wondering, would shorting an XLR plug pins (2nd and 3rd) bring harm to audio interface or is it safe?

For last two days I've been doing many things to get clean audio at my end for ex:
I rearranged the usb and power cables, shuffled the power sockets and plugs so that nothing overlaps on anything:

Its seems something is working now This recording sounds cleaner to my ears but you will be the judge:

I set the gain to 50% in AI

1. I did two recording one using ASIO driver and other using Waveout driver in Reaper:


Used ASIO drivers Gain 50% (first 10 seconds are room tone):

Dropbox - Laptop_ASIO-Gain50%.mp3 - Simplify your life


Used Waveout drivers Gain 50% (first 10 seconds are room tone):

Dropbox - Laptop_WaveoutDrivers-Gain50%.mp3 - Simplify your life


2. After listening to the audio files, do they sound clean recording?

3. And is the gain appropriate? (if I had increased the gain in AI then mic would have picked up noise because it was noisy outside while recording)


[MENTION=89013]TalismanRich[/MENTION] I noticed you said you record at 50% gain so I did the same and recorded at 50% gain which in result picks up less noise. Let me know your opinion.

 

[ecc83]

The second recording was pretty good. Noise floor at start around -60/-70 dB fs but running the clip through a ~100Hz high pass filter cleaned even that up to well below -70 apart from a blip. No idea about that, could have been someone switching a light on or off.

It is good (standard?) practice to HP filter everything UNLESS you actually have bass information in there. You can listen to the track and move the frequency up until the voice thins out or gets 'weird', then back off a bit.

Just had another look and your modulation level could come up 3dB or so? You peak at about -14dB fs but only think about this IF you are still unhappy with noise levels and get the track louder by moving closer to the mic (where the HPF comes in again to combat 'proximity effect)

In general though, always err on the side of lower levels.

Dave.

 

[TalismanRich]

Just gave the samples a listen, and they are vastly improved over the previous ones. The noise is pretty much gone and all I'm hearing is room noise.

Dave's suggestion of running a high pass filter is a good one. Since you're only recording voice, and your voice isn't a deep bass style, you can easily clear off anything below that 80-100 Hz range withouth affecting your voice.

Good job!

 

[CatMalone]

The second recording was pretty good. Noise floor at start around -60/-70 dB fs but running the clip through a ~100Hz high pass filter cleaned even that up to well below -70 apart from a blip. No idea about that, could have been someone switching a light on or off.

It is good (standard?) practice to HP filter everything UNLESS you actually have bass information in there. You can listen to the track and move the frequency up until the voice thins out or gets 'weird', then back off a bit.

Just had another look and your modulation level could come up 3dB or so? You peak at about -14dB fs but only think about this IF you are still unhappy with noise levels and get the track louder by moving closer to the mic (where the HPF comes in again to combat 'proximity effect)

In general though, always err on the side of lower levels.

Dave.

Thank you Dave, I'm working on your advise and will get back to you once I improve on that to share my result.

1. Dave, BTW today I received the XLR cable and other stuff etc.. so should I short the 2nd and 3rd pin on XLR plug etc.. and do the rest as you instructed me?
Will it help us to find out any issue in Scarlett solo (if there is any)? I'm also willing to know if this AI is working fine or not.

2. Secondly, I'm concerned about is: If I short an XLR plug pins (2nd and 3rd), will it be safe for audio interface? (as Its not under warranty any more)


----------------------------------

Also thank you TalismanRich

 

[ecc83]

I for oe would be very interested to learn the results of someone doing the same 'silent' recording test on another Solo but then I AM an old teckky bugger!

No, shorting pins 2&3 will cause no harm at all to the interface.

However, your recent recordings would seem to show that you have eliminated the noise for all practical purposes? I suggest you keep those clips on file and repeat the test, monthly say? Noise can creep up on you, a change of layout or the addition of some other piece of gear can bump up the noise again. Things like DC 'line lump' power supplies are especially prone to inducing hum and hash.

Dave.

 

[CatMalone]

I for oe would be very interested to learn the results of someone doing the same 'silent' recording test on another Solo but then I AM an old teckky bugger!

No, shorting pins 2&3 will cause no harm at all to the interface.

However, your recent recordings would seem to show that you have eliminated the noise for all practical purposes? I suggest you keep those clips on file and repeat the test, monthly say? Noise can creep up on you, a change of layout or the addition of some other piece of gear can bump up the noise again. Things like DC 'line lump' power supplies are especially prone to inducing hum and hash.

Dave.

Thank you, I've kept those clips on file and sure I'd repeat the test every month...

Yesterday late night, when I was about to record neighbors started making noise by running their water pump (Utility pump which fetches water) and also filling bucket (they usually do this at random time). I tried to remove this with high pass filter but seems like it is different kind of noise

Just to help you let me elaborate: In this sample audio:
- Till 39 seconds its a slow noise of water pump and also bucket filling noise
- After 39 seconds its bit loud noise of only water pump
- And after 1 min and 15 seconds I started speaking for a few seconds
(I was very close to the mic)

(it's kind of whistle sound but actually water pump/Utility pump is making this noise)

FYI: In audio file there will be a room noise so please ignore it as I didn't do DIY acoustic treatment (I manually do it everytime while recording)

Sample audio (320kbps):
View attachment water-pump-Noise_3am_5am--Gain-50%.mp3




[MENTION=89013]TalismanRich[/MENTION] I also request you to please share your opinion about this sample audio.

Thanks in advance!