@@MusicCityAcoustics Hello, I am trying to understand relation between audio interface calibration and usage of USB microphone like UMIK-1 from miniDSP. I mean what is calibrated during loop back procedure of the audio interface? Input or output? Seems to be too many variables in this equation. On top of this USB embeed ADC of microphone takes the role of interface input, correct? So in case of UMIK-1 is the audio interface calibration relevant and important?
I'm so glad the video helped! REW can be a little daunting but it is a very useful tool once you break it down to the basics! Thanks so much for the comment. Cheers!
The output of your audio interface is the one that connects to your speaker. So instead of connecting it to your speaker connect it back into the input of your audio interface.
Thanks so much for this video! I started out knowing NOTHING about this, and feel like I'm on my way to making my home basement studio much less horrible sounding :)
Great video! How do I calibrate the sound card if I use the built-in sound card in my HP ProBook laptop? The sound card output is the 3.5mm headphone jack going into my amplifier's RCA input jack. The sound card input is the USB socket of my laptop where I would plug in my MiniDSP UMIK-1 USB microphone. How do I "plug the output of the "interface" directly into the input of the "interface" "? When you say the "interface", are you referring to the amplifier used to drive the speakers to be measured? What if my amplifier only has analog inputs (RCA) and analog outputs (speaker-out)? Thanks if you could help me understand.
You can’t. There’s nothing to show because every single microphone has its own frequency response curve that needs to be accounted for. If you can, I would look into saving up for Soundworks SoundID. It comes with a reference mic and the calibration file downloadable from their website. Then the added benefit of speaker EQ is worth its weight in gold.
Hi Dennis, a body will have very little impact on the measurements at lower frequencies. With room measurements, this is primarily what we are looking at. At higher frequencies, any small movement of the microphone or objects/people will have a meaningful impact on the results. This is why it is important to stand away from the microphone or leave the room. Unfortunately, both your head and microphone can not occupy the exact same space but this does not make the measurements invalid.
I thought the same. How often do we use our speakers when we are not in the room? Our presence is a constant to me. Playing sound while not in the room seems pointless.
I'm completely lost on what you're doing on the sound card calibration. What do you mean plug the output to the input of your interface? What interfact? I'm using a laptop so my soundcard is built in.
Thanks for the video! I see in the comments a couple of people ran into the same issue that I did: everything seemed to be set up properly but REW isn't getting the input. Check the privacy settings on your MAC and make sure REW has access to the microphone (even if using an external audio interface)
Thanks for sharing this :) Just a thought - would it not make sense to stay seated where you'd usually be sitting when taking the sweep measurement, so that the any effect your body has on acoustics is taken into account also? edit: I realise as I'm watching the following video that this might be quite difficult considering the measurement mic needs to be where you head would be..
Great video! I'm struggling with the preferences as I'm using my Hegel as soundcard (USB frommpc to Hegel) and it doesn't get to -12 when calibrating... I turn the volume all.the way up and it reaches like -15 and then calibrating is an horrendous sound almost break my ears. Any idea of what is happening? If I use my PC soundcard at all volume it barley reaches -25 db
Re the soundcard calibration @ 3:12: The soundcard calibration cannot address or correct distortion. If the interface has poor distortion characteristics, it is what it is - there’s no fixing that. Getting a different interface is the only option.
All the home theatre peeps will be wondering what the hell is an audio interface is and why we need to calibrate our soundcards lol I take it if were using a pre/ pro we dont need to worry about calibrating soundcards and connecting audio interface etc?
Hi Isaac, that's right. The calibration process can be tough in home theatre and listening room setups and is not critical to getting accurate and reliable measurements for room acoustics applications.
I'm completely confused on what an "audio interface" is. You're using a Duet but I have no idea what that does and why you need it. Don't you just need a microphone? I have a UMIK-1 and a Windows laptop. Do I really need anything else?
If you have a USB microphone, you do not need any interface. An audio interface like our Duet is a digital-to-analog and analog-to-digital audio converter, and it has microphone preamps and monitor level control built into it. This is a very common set up for studios but not typically what you'd have in a dedicated listening room or home theatre.
on heavens sake why step out of measurement??? u must measure with you in listening position… otherwise is useless! you calibrate the room in the listening position… so when you listen you are in the listening position and your body is in the path of acoustical signal so it influences the acoustics…
You will not be sitting in precisely the same position for every measurement, and this is usually to address treatment concerns, most of which fall into the lower end of the frequency spectrum and are not frequencies generally influenced to any significant degree by the presence of a person.
Thanks, I got a peculiar problem in trying to level the interface input level to the -12 dB! I could only hit -17 dB with a hell of amount of distortion. My interface is Focusrite Clarett 8PREX and i connected everything as told. There does not seem to find a way neither to calibrate nor set the levels right!
Had the same problem. You can see under the "loopback input" there's an "Input volume", you can increase it by clicking the arrows. This will solve the problem. Sorry for my horrobile English :)
I think we're on the same boat! My interface is a Scarlett 18i20 and it can only go up to -18db before the sound distorts due to the feedback. Even on such a low level, when I start the process of creating the calibration file, the program shows a warning that occured clipping! I don't know what to do...
Apart from the frequency response almost all the measurements are speaker agnostic. Your decay times, standing waves, etc. do not care what speakers you have. For example if your room has a standing wave at 50Hz and you speakers can reproduce 50Hz at all you will see a long decay time. no matter if the speaker produces it a few db quieter or louder. REW (as the name implies) is meant for measuring rooms. You have your speakers, you measure your room treat it and make it sound as good as possible through acoustic treatment and speaker positioning as well as EQ. When you change your speakers you do this again to get the most out of them. If you treated the room for some perfect speakers (0 distortion, perfectly flat from 10Hz to 20kHz with no phase shifts, basicaly what you would get if you had a calibration file for them.) and then plugged in REAL speakers it would sound bad. You want to measure the speakers you have, not the ones you dream you had. If you don't you just get a worse sounding result.
it would be nice to have some tests with these panels that you have there in your studio to see the difference with the acoustic treatment. And explain how using waterfall chart works to see reverbs Top Channel one more subscriber and one more like Thanks for helping
Hi Edy, thanks so much for your comment. We'll be covering all of that and more in part two. I'll be showing measurements of a room with and without acoustic treatments, as well as how different speaker and treatment placements can affect things.
Hm I dont understand how to calibrate my soundinterface. I have a Presonus Revelator IO24. How can I connect my XLR socke with my Headphone 3.5mm socket ? I want to measure the frequenz of my microphone with different pop filters.
I'm trying to use a UMIK-1 and REW on my laptop to measure the in room frequency response of my stereo setup (connecting to my DAC via laptop's USB output), but you lost me at calibrating the soundcard: "In order to calibrate your soundcard, you need to plug the output of your interface directly into the input of your interface" - what do you mean by that? Why do we need to calibrate our soundcard. Maybe these are obvious questions, but I'd really appreciate your help!
REW says calibration is not needed (or even possible) since "SPL calibration is not required, REQ is already calibrated for the USB mic you are using based on the sensitivity data in the mic cal file."
So since you calibrate to 80spl should all your measurements record in at 80 SPL as your reference zero on the graph? I calibrated at 80 but my graph only peaks at 70?
Question: and how do you know that these deviations are of the room and not of the speakers. almost all commercial HiFi speakers have +-5db response deviations
My understanding is that it doesn't really matter. The goal is not to measure the speaker or the room but the combination of both and to ensure that the combination sound as it should.
Hi Evan, great question! Unlike most microphones used for recording that are designed to sound good or pleasing, measurement microphones are designed to have a flat frequency response to provide accurate feedback and measurements. There are two other main differences, one, they are omnidirectional, and two, they often have a calibration file that accounts for any variation in their frequency response. The cal file can be loaded into REW, so the microphone's frequency response is accounted for in your measurements. When looking at room acoustics, we are often looking at the room's low-frequency response. It is always ideal to use a measurement microphone for accurate results, but if the only mic you have is a cardioid condenser microphone, you can use it to get a better understanding of what is happening in your room. Just remember your measurements will also be showing your microphone's frequency response.
I followed this tutorial and got an excellent reading, not too unlike the one you got in your office. (Excellent in that things looked right, not that my room is great). A few things could be explained better for those using interfaces. You may need to go back into preferences after you calibrate the interface and change your setting for your outputs and the mic input. For purposes of a home studio, why would you want to take readings using anything but both speakers at the same time? In any event, thank you for this. Do you guys offer a free analysis? if so, how do we send them to you?
Hi Robert, we measure the left and right speakers independently because of the distortion that occurs when measuring the left and right speakers together. Measurement microphones are extremely sensitive (much more so than our ears), and as a result, if there is the slightest variation in distance from the microphone to the left or right speaker, this will show up on the measurement as a large drop off in your room's high-frequency response. It does not provide a realistic representation of what we would actually hear or perceive in the room. When analyzing lower frequencies, both speakers can be measured together, which is why a typical measurement set would include the Left, Right, and Left and right tests. I hope this helps. We have a Free Room Advice Form on our website that is a great way to get started if you want to get in touch with us. We don't offer free REW analysis as that is typically a pretty long and intensive process with lots of measurements to analyze,e but we'd love to talk with you more about your room and see how we can help! You can find the form here: www.musiccityacoustics.com/free-room-advice
Great Video! But why leave the room during the measurement? Isn‘t the listener at listening position a fixed part of the room itself that influences frequency response during mixing/listening? Thanks!
Good point. Unfortunately our head and microphone can't occupy the same space so one of them has to move for measurements. I typically just moved away from the microphone as our bodies will have a significatnt impact on the high frequency response if we are close to the microphone, we have little to no effect on lower frequencies though. Leaving the room for our purposes is not super important but is the "technically correct" approach when testing room acoustics or gear.
Hey! Any idea how I can load in a Cal File for other non room measurement Mics? Like say I'm using a C414 BULS for example, is there a way to load any frequncy response graphs, or what Mic it is/specs manually? Just a thought, because for most Mics you can get the general Freq Response graphs, but also in the case of some Mics(usually older ones), they will even come with actual FRG for the actual Mic. So maybe you could make a feature to somehow load in at least a FRG, or even make one?
This would be awesome. The way it works now you really only have two options: 1--You buy a cheap USB microphone that comes with a compatible calibration file. Or 2--you buy a really expensive calibrated measurement microphone that is truly flat so you can use the default "flat" mic response in REW. Wouldn't it be nice to be able to use all of the mics and preamps that exist in the space between these 2 extremes?
@@guy48065 You can still definitely use any mic, but it's just not optimal I presume. Also, I'd only use a Non measurement Mic that is fairly flat, but you could use anything. I dunno if it would be possible to make a feature where the user loads in the Freq Response Curve, and also I don't know how accurate most of the general Response Curves are that the Company's release. They might not be in depth/accurate enough, Im not sure. I just thought, since you can technically you can use any Mic, that maybe loading a Factory FRC might get you a bit closer, or maybe EQ Wizard could start loading in Specs for different Studio Mics, but at the end of the day that's a lot of time/labour when the programs free, and people can access cheap Measurement Mics.
MCA, Thanks for the video. I am looking forward to getting my HTR measured once construction is complete. I am new to these types of tools and processes. I am a bit lost with part of your set up instructions. I am going to be calibrating my system/room through my AVR and I'm running a 7.2.4 Atmos configuration. How do I run the signal thru my AVR so the sound is emanating from the speakers? OR am I supposed to bypass my AVR and use a multichannel device to send audio thru my speakers? Can you explain in another video maybe how folks can measure a room with REQ wizard that are processing audio through a sound system? Obviously I'm missing something so any advise would be very much appreciated. Thanks!
This is an amazing guide - thank you! One question I have is regarding measuring a 2.1 system: The first time around I tried to measure a 2.1 I did so using all L+R+S channels simultaneously. This resulted in some serious phasing in the high-end ruining the measurements. I then got a tip about doing the L and R separately and vector averaging the results. This does make sense, however where does that leave the sub? Do I measure the sub separately as well and add that to the vector averaging? Because I'm guessing running L+S and then R+S wouldn't give me good results. Thanks in advance!
Have watched both these vids several times - ordered my mic, got all my gear together, finally have a few minutes to mess with it! Installed REW and...........it won't work. The program installs fine, loads fine, but none of the buttons respond to mouse clicks. Program also won't close without ending it in task manager. Plenty of memory available, stable long-term system that's never given my any problems - my dedicated studio computer. I really hate technology sometimes.
Hey Patrick, I am so sorry to hear REW isn't working for you. I am a computer expert or tech guy, so I'm not sure what the problem would be beyond some of the more common things. We aren't affiliated with REW at all, so I don't know much about it beyond using the software for acoustic measurements. Several versions of it are available to ensure it is compatible with your operating system. That might be something to look into? Sorry, I can't be more helpful on this front.
@@MusicCityAcoustics No worries I'm just lamenting - good news is I'm up and running! Not without issues though. Computer does seem to be acting up a bit and I'm working to figure those issues out. I moved my computer to a different location after some initial measurements and since then some strangeness I can't explain ensued - could be my interface, or mic, or perhaps software settings. I can not get my mic to the 80db without pretty much maxing out the mic gain and it was not that way before. Wondering if this will cause issues with the measurements? I am getting messages after each measurement that clipping was detected but the tracings still appear usable.
You are very welcome! REW does have RTA functionality but I'm not super familiar with SMAART so unfortunately I can't compare the two. REW can certainly be used to measure large rooms and systems though.
Hi Bill, the Duet is the audio interface I used to get audio in and out of my computer. This video is geared towards taking measurements in home studios. Many of the same practices apply to home theatres and listening rooms, but the hardware for each tends to be a little different; you can absolutely use your Umik1 USB measurement mic plugged directly into your laptop and come out via HDMI to your receiver and then to your speakers to take measurements. That hardware configuration is quite different from what you would typically find in a studio setting, so I didn't talk about it here. When setting up the audio inputs and outputs in the preferences window, you would just select the Umik1 as the input and the HDMI for the output. Thanks for watching!
For those having issues with the microphone calibration files, it was very picky with the txt file I used for my Behringer ECM8000. I have to edit the txt file to include only the freq and spl# and make sure for plain text as well as proper returns after very line. Hope that makes sense.
Dude at 3:54 your inputs and outputs change from LL and LL to RL and LR!!!! WTF? You don't say what inputs and outputs get tied together, left only or left and right? You have to make these details clear. On my system using AVID HDX the REF meter tracks the IN level and both track the output level, all set to L out and in. I can only get to about -20 on the IN with the OUT set to -12
Hi Chris, sorry for the confusion. It doesn't matter which input and output on your system is used. When making the video I was filming it, recording, audio, and walking through the process of setting up REW. The IO changed because I was using the same interface to to record the audio and to walk through the set up. Do you have any way to increase the output or input level on your system? If not and you are using REW for room measurements, skipping the sound card calibration is not the end of the world.
You said any interface correct? I used a 2021 27” IMac (Monterey O.S.), 1 pair of 8” KRK’s, 2 channel Steinberg UR 22 interface (2 inputs, 2 outputs), Analyzing microphone and a digital sound level meter. I followed the same setup process and it did not work correctly for me. I was getting weird things happen that I did not see happen in your steps. Any other suggestions?🤔🤷🏽♂️
You said any interface correct? I used a 2021 27” IMac (Monterey O.S.), 1 pair of 8” KRK’s, 2 channel Steinberg UR 22 interface (2 inputs, 2 outputs), Analyzing microphone and a digital sound level meter. I followed the same setup process and it did not work correctly for me. I was getting weird things happen that I did not see happen in your steps. Any other suggestions?🤔🤷🏽♂️
at 7:44 which signal source should be selected when using both speakers and sub? You say that you selected "REW speaker cal signal" because you doesn't have a sub in the room. You would expect that there would be a "REW speaker and sub cal signal" option for users who use both speakers and sub in their monitoring setup but there isn't. Thanks
I always use the speaker signal for calibration unless I am only testing a sub. If testing a speaker and sub together, I would use the speaker calibration signal. Subwoofer levels are largely subjective unless you are aiming for a flat frequency response. As a result, calibrating to the sub and speaker level would be quite challenging. I hope this helps!
@@MusicCityAcoustics Thanks for the reply. Just to be clear, do you mean that you don't recommend measuring speakers and sub simultaneously? Also, I would appreciate your answer to one further question: At 10:48, which of those output settings refers to the sub alone (I’m guessing it’s C or LFE)? And if I wanted to take a measurement of the speakers and sub simultaneously, which of those output settings would I use? There doesn’t seem to be an output setting for L+R+sub. Thanks
Use the speaker cal signal. When balancing subs and speakers, it is typically the sub-level that is adjusted. Because of this, we want to use the speaker level to calibrate the measurements. Then if more or less low-end energy is needed, the sub-level can be adjusted to provide the desired frequency response. I only use the sub cal signal when measuring subs by themselves.
@@MusicCityAcoustics Thanks but perhaps I wasn't clear on my last question. I understand that I should use the speaker cal signal but in my last question I was referring to which output to select. At 10:48 in your video, there are a list of outputs. Which one refers to the sub? And which output refers to the speakers + sub together? Thanks.
@@walshythemusician you absolutely should measure the sub and speakers together as well as measure them individually. In most studio setups, the output of the interface or monitor controller goes to the sub(s), and then from the sub, the L and R speakers are fed. This negates the need for a separate output from REW for the sub. If your sub is on a separate output from your interface, say 3, for example, then you'll need to look at using the C or LFE output, but I've never had to use them before.
Just not following why your loopback setting was all L channel but after you connected the interface it was Output R input 1 and on Timing Reference output it was output 2 and loopback input 1. For the initial calibration are you connecting a L output to a R input?
Hi! While filming this, I was monitoring the output of my interface on the left channel, so I could not use it or the calibration. The sound card calibration can be done with the left or right output. Interfaces should be identical, if not nearly identical, from channel to channel, so the left or right output won't have a significant effect here. I wasn't using the loopback functionality in the video, so those settings were just left on the default.
It is always a good idea as there is a sound-card in your computer. If you can't get the calibration process to work, you can take measurements without doing it though. Most sound-cards have a very flat frequency response and if there are any variations in performance it typically is in higher frequencies and room measurements are primarily focused on analyzing mid and low frequencies.
@@MusicCityAcoustics I assume that it is not necessary to calibrate the sound card if you use a usb mic like UMIK. This is stated on the rew website "Calibrating the Interface This step is not applicable when using a USB microphone as the input, skip directly to Check levels"
I am trying to use the UMM-6 to calibrate my home theater. Do I still plug the mic into my computer and run all these steps? How does my Marantz AVR, the thing I really want calibrated, fit into the calibration? Or am I completely misunderstanding the process?
Great tutorial and great software MCA! Out of curiosity: if you are measuring with your SPL meter at 80dB as adviced, does this mean that when starting a measurement the speaker will output a signal of 80dB? In other words: when reading the SPL graph the reference line should in this case be the 80dB line? I want to make sure I'm for example having a to high frequency response in my low end or a to low frequency response at my high end...
Hi! Thanks so much for watching. We calibrate the system so the output level of the speaker is 80dB at the location of the microphone. The actual speaker output will be higher than this. After calibrating the input of your measurement microphone to 80dB, if your room and speakers were perfectly flat, your measurement should be right around 80 dB. Of course, in all rooms, there is a lot of variation, so things will go above and below 80dB. Thanks for your question! -Graham
@@MusicCityAcoustics If decide to go the MiniDSP USB measurement mic route as suggested on the REW website, do I need the standalone SPL meter at all? And since I will be using an Apollo x8p interface essentially only to drive the test tone to the speakers, am I going to need to do a sound card loop back calibration?
Is not that intuitive with the Steinberg URC22. Here we have not alone one control for the output but controls vor DAW, Input, Input mix. I tried out all possible settings, but could not get an proper adjustment of the level control in the preference card. I do not really understand to handle these controls. Any idea, how to manage it?
Thank you for the video! I can follow everything your talking about except i can't read your screen. In the lower output and input boxes..aka drop down boxes .is it also set to your presonus interface? It looks like it's different but i can't read it. I have a UA twin X and i am using channel 1 which is the XLR/line input with my Behringer 8000 as my measurement device... from what i understand I'll select output as L and input as L in the lower drop down box in REW. And R as loopback input and R as timing reference... is that correct? Also would i need to connect a TRS from the 2nd channel of my interface which is an XLR/line (aka R input according to ReW) and feed the the other end of the TRS to the Right monitor out or is the Right line out sufficient? Or even the Headphone out? Thanks again for your video
I'm having massive problems using REW. I've started the process, but when I run the first part of the configuration with Input and output at L, and at -12 dB, once completed, I get an error message stating "The soundcard measurement varies by 14 dB between 10Hz and 20kHz, this is much higher than it should be, the measurement may not be valid and should not be used to make a calibration rile." My Soundcard file in green begins at -2.2 dB and progresses on an approximate 45 degree climb to 2 dB, then dives straight down at 20kHz to zero. The phase is listed at -22 degrees starting at -1.1 dB going down to -1.5 dB at 20Hz continuing flat until 300 then dropping to -2.2 dB at 8kHz where it spikes straight up -0.1dB and then drops down to -2.2dB on a steep curve at 20kHz. I ran my Sonarworks software prior to this. Would that be causing this problem and should I delete that profile prior to running REW?
I've tried multiple times to get the soundcard calibration file of my Scarlett 18i20, but the frequency response looks very unsual to me. There's a ton of big sine waves at frequencies higher than those of the high mids, if I remember correctly. I tried to do the same process on my scarlett 2i2 and the frequency response was super flat! So, my question is what should a soundcard frequency response look like? And, is there any possibility that my soundcard has any issue? I've been working with no problem so I'm pretty lost trying to find the answer here.
Hi John, sorry it is giving you a hard time. In most cases, the soundcard's frequency response is nearly perfectly flat. I'm not sure what is going on with the 18i20 calibration, but you can skip this step if you can't get it working.
Mine too, apollo twin has a big spike 97 Hz and pretty much all over the spectrum. The phase is just pretty much just a big band instead of being a line. Maybe the scale of the graph is different? My soundcard response from -90 to +39 SPL and the phase from -25 to +25.
I am experiencing the same problem. After connecting my input 1 to my output 1 my graph was showing a linear in stead of a flat horizontal line. I than did a calibration with my output 1 to my output 1 whilst also having connected my output 2 to my input 2 and the graph suddenly shows a flat line. No idea if this is a solution or if I'm doing something wrong with a lucky outcome.😂
Super helpful. Will come back when I have my measurement mic and my gear set up. Greta delivery of information for a relative novice like me but its all starting to make some sense! Many thanks- I'll be back!
thanks for this one! so many videos so badly explained. I wish REV would make the resulting graph a readable graph to start with! what is the point in featuring the overcomplicated not really usefull grahp first and force you to make multiple adjusments when we all know 99% of us will like to get a base line (!) and easily readable the amount of dbs over and under, easily seeing dips and peaks. As now you have to start making changes all of the time and comparing points values and counting, whyyyy? I thought the principle is present first the simplest most useful version and then let advance needs and users look for the other parts. ...
Hey Travis! I'm not sure what the issue is with Apollos, but we've had a few people reach out to us with similar problems. My guess is it has to do with the UA software and internal routing, but I'm not sure. If you can't get it to work, you can take measurements without calibrating the interface. If you are designing pieces of hardware gear or building speakers, I wouldn't recommend this, but for room measurements where we are primarily concerned with the low-frequency response of the room, it is fine.
What if your using a preamp? Why turn up the output on your Duet VS preamp input when calibrating your interface? You said you calibrated it at -12 dbfs, but I thought you said 80 db?
So I have a digital RadioShack sound level with a RCA output connection on it. I guess what I'm try ask is will the digital display RadioShack Sound level meter work?
Thanks for your question! On our website, we have a Free Room Advice form. You can include your measurements there as a zip file. www.musiccityacoustics.com/free-room-advice
I am starting to treat my small newly built garden studio which I intend to use mainly for mixing. Should I use REW to take my readings separately on each speaker, both at the same time, or just take one reading of one speaker? Is there any advantages or disadvantages to these options? I do have a glass door in one corner of the room which is the only thing that is not symmetrical. 😎
You'll want to measure each speaker individually and the left and right speakers together. If you haven't checked out Part 2 yet, it breaks down in much more detail how to analyze the measurements! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CuEwoeN7ZJk.html
Am I supposed to move the speakers for the measurement? My room is roughly a 4x4.5 meters, and my deck is on the corner, as I have my treatment on the corner (it's an home studio, this wayt I got more space and I avoid a little beat the first reflections from the side)
You want to measure with everything as it is with the microphone at your listening position. You want to measure the real sound not some best case scenario as you don't use the speakers in the best case scenario.
Pros in studios don't even bother with them. Sometimes they're wrong to begin with-- you're better off just accepting any small deviation. Best chances are that it'll be the lesser of evils.
Great Vid! Two part question: at 3:34, where input goes to output, is that the timing reference or sound output? Is the input the same input as the mic - or the loopback in? (ie. I'm using TLS for the loopback signal and then swapping in the Mic afterwards). Running on the Motu M4, currently I'm not able to bring it below 11.52dB doing a loopback line out to line in (TLS on mic channel), even with the gain turned to 0. Running ASIO drivers. I thought I had this figured out yesterday. But today, something has gone awry. Does your experience have any insight on this that you are willing to share?
Thanks so much! Hopefully, I can help with your questions. 1. The loopback captures the interface's frequency response for calibration purposes. What we show in the video is to create the calibration file, not a timing reference. However, you can set up a timing reference for your measurements using this same loopback configuration on an interface with two or more inputs/outputs. This is particularly helpful and needed when analyzing phase and group delay 2. For the calibration loop back, I set the input to line level. If you try to run the calibration measurements with the input on your interface set to mic input instead of line level, it will distort. I believe that is what you are currently experiencing. I hope this helps!
@@MusicCityAcoustics You're amazing. I thought it was a line-in unless phantom power was on. But everything is so low - and REW asks for the levels to be raised. I'll check into the line level stuff. Cheers
@@MusicCityAcoustics Wait, something doesn't make sense. If you're telling users to not use their microphone preamps while calibrating the interface, the coloration of the preamp will not be included in the calibration. That means, when you do use the preamp when measuring the room with your microphone, you will not be getting as accurate of a measurement. How does this make sense?
Hi Benny, you are so welcome! Thank you so much for watching and for the positive feedback. It makes all the work that goes into making the videos worth it!
Sorry to hear it is not working for you. Unfortunately, I am not sure what the problem would be. REW's website and help resources should be able to provide more insight www.roomeqwizard.com
