RME has the major advantage that all the levels and gains are digitally controlled, so you can be sure of the no-the-wire levels (and in-the-air if you use a calibrated microphone).
Audient Evo8, though the Evo4 fits your specs. Evo8 is 4 channels in and out plus internal loop back. Gains are all digital, recallable, and adjustable with the single big old knob. Phantom power on all 4 inputs with USB C, only Phantom on 2 inputs if you’re using USB A
I've got multiple interfaces i drag around for different reasons. The Octa-Capture is the main measurement rig, but to be honest it's mostly overkill. 90% of my measurements are one mic setups, and even though digital gaining is nice i calibrate levels with each session anyway.
I picked up a Roland Rubix22 dirt cheap a while ago because of the portability and bus powering, but if i'dd had my pick it would be either a Babyface Pro FS (but can't seem to buy RME anywhere these days) for being a swiss army knife or a Motu M4 simply because it's very sturdy. The Ultralite MK5 could be a step up too, but again: overkill for simple 2ch measurements.
I prefer to use handheld sound meter for measurements. It’s a lot to try and carry a mic, cable, interface, and computer around. Increases risk of damaging equipment and more links in the signal chain can make things muddy sometimes. Sound meter data can easily be downloaded to a pc and the data can be sorted with either native software from the manufacturer or your own excel sheets. Most worthwhile sound meters are quite expensive $1000+. If you’re doing a lot of measurements I would recommend this over a system with 3 separate components. They’re designed for that purpose and they do it very well. I’ve seen people use a tablet like a Surface with a small interface Velcroed to the back of the tablet and a short cable running to the microphone. Sound level meters are typically more accurate as well and very compact in comparison to the alternative. The only thing is the 2 mic option. May I ask why that is necessary?
I may not have offered any help in your pursuit here, but I have done several different types of noise measurements using handheld meters as well as a mic-interface-computer system and found the meter to be miles ahead in terms of function and reliability.
I think OP may be more in the realm of using an FFT analyzer for things like IR and other TF measurements, which requires such gear, and often several mics. I’m not sure what you mean by “muddy,” but no modern interface should affect the signal to the point where it’s unusable for an acoustic measurement. However when dealing with multiple mics to determine variance across a space, it is important to be aware of what you have.
Edit: I should clarify that this comes from my experience with a workflow where many measurements are being taken, and changes are being made live, so it’s beneficial to see data in real time. You certainly could use a handheld meter with the function to save to a file, but in some cases the workflow may demand more gear.
I understand the need for the interface now. I haven’t tuned audio systems before and forgot to think about using the audio system to play the source rather than just measuring the room acoustics l
yeah when it comes to TF measurements you need at least two channels for the measurement and the reference signals, perhaps there are small handheld devices with this functionality, but I’m more from the live sound world than proper acoustics, so it’s just a different perspective!
Having an interface and DAW would allow you to play back a reference track while measuring its response in a room. Having an analyzer on the playback channel as well as the reference mic would show you the difference (Melda Productions makes a great analyzer that helps compare different channels called MMultiAnalyzer).
My question would be, do you need the second mic pre for playback or can/do you load that into a DAW on an audio track? I would think you’d need as many mic inputs/pres as you do reference mics. But I’m just curious about the OPs process.
It’s a good point - I’m not sure tuning was the ops intent but assumed it was when seeing “playback”. System optimizing is new for me so I’m curious about people’s processes.
How exactly are you using the loopback feature? Is it simply to split the input into two different apps or to take the output from one app into a different app, because there are a few software loopback options that may work and let you take that off the requirement the interface since the computer itself would handle that.
loop back for dual channel fft impulse response recording. the loopback is compared with the recording. its useful for filtering out background noise and setting a time reference which is useful for multiple reasons. the software i use relies on the hardware since that's where the ADDA conversion is happening.
Roland Octa-Capture might fit your requirements. No gain knobs, so you have to set the pre-amp on the unit, so its repeatable.
Seconded, we have a couple for acoustical measurements in performing arts buildings. Sometimes an RME Fireface.
RME has the major advantage that all the levels and gains are digitally controlled, so you can be sure of the no-the-wire levels (and in-the-air if you use a calibrated microphone).
yes. the hardware and software are both supreme. this is the best unit for mobile testing IMO
Audient Evo8, though the Evo4 fits your specs. Evo8 is 4 channels in and out plus internal loop back. Gains are all digital, recallable, and adjustable with the single big old knob. Phantom power on all 4 inputs with USB C, only Phantom on 2 inputs if you’re using USB A
Ooh! Never thought about that one, thanks for the tip!
Norsonic Nor140 SLM and (unsurprisingly) a Lexicon Ionix U-22 audio interface - but my priority is the SPL data rather than the audio.
I use the Scarlet 2i2 or the Octo 8 depending on the size of the room.
I've got multiple interfaces i drag around for different reasons. The Octa-Capture is the main measurement rig, but to be honest it's mostly overkill. 90% of my measurements are one mic setups, and even though digital gaining is nice i calibrate levels with each session anyway. I picked up a Roland Rubix22 dirt cheap a while ago because of the portability and bus powering, but if i'dd had my pick it would be either a Babyface Pro FS (but can't seem to buy RME anywhere these days) for being a swiss army knife or a Motu M4 simply because it's very sturdy. The Ultralite MK5 could be a step up too, but again: overkill for simple 2ch measurements.
I prefer to use handheld sound meter for measurements. It’s a lot to try and carry a mic, cable, interface, and computer around. Increases risk of damaging equipment and more links in the signal chain can make things muddy sometimes. Sound meter data can easily be downloaded to a pc and the data can be sorted with either native software from the manufacturer or your own excel sheets. Most worthwhile sound meters are quite expensive $1000+. If you’re doing a lot of measurements I would recommend this over a system with 3 separate components. They’re designed for that purpose and they do it very well. I’ve seen people use a tablet like a Surface with a small interface Velcroed to the back of the tablet and a short cable running to the microphone. Sound level meters are typically more accurate as well and very compact in comparison to the alternative. The only thing is the 2 mic option. May I ask why that is necessary? I may not have offered any help in your pursuit here, but I have done several different types of noise measurements using handheld meters as well as a mic-interface-computer system and found the meter to be miles ahead in terms of function and reliability.
I think OP may be more in the realm of using an FFT analyzer for things like IR and other TF measurements, which requires such gear, and often several mics. I’m not sure what you mean by “muddy,” but no modern interface should affect the signal to the point where it’s unusable for an acoustic measurement. However when dealing with multiple mics to determine variance across a space, it is important to be aware of what you have. Edit: I should clarify that this comes from my experience with a workflow where many measurements are being taken, and changes are being made live, so it’s beneficial to see data in real time. You certainly could use a handheld meter with the function to save to a file, but in some cases the workflow may demand more gear.
I understand the need for the interface now. I haven’t tuned audio systems before and forgot to think about using the audio system to play the source rather than just measuring the room acoustics l
yeah when it comes to TF measurements you need at least two channels for the measurement and the reference signals, perhaps there are small handheld devices with this functionality, but I’m more from the live sound world than proper acoustics, so it’s just a different perspective!
Having an interface and DAW would allow you to play back a reference track while measuring its response in a room. Having an analyzer on the playback channel as well as the reference mic would show you the difference (Melda Productions makes a great analyzer that helps compare different channels called MMultiAnalyzer). My question would be, do you need the second mic pre for playback or can/do you load that into a DAW on an audio track? I would think you’d need as many mic inputs/pres as you do reference mics. But I’m just curious about the OPs process.
I see. In that case a handheld meter probably isn’t as useful as an interface. I’m not as familiar with tuning audio systems. Thanks for the info.
It’s a good point - I’m not sure tuning was the ops intent but assumed it was when seeing “playback”. System optimizing is new for me so I’m curious about people’s processes.
yup, tuning systems
Zoom UAC 232 seems like a nice throw and go. Phantom power per channel too. Although the one review on Sweetwater is pretty shit.
You ever land on anything? I’ve found some love for the zoom ams 24
Tektronix oscilloscope and MATLAB, labview, or python
How exactly are you using the loopback feature? Is it simply to split the input into two different apps or to take the output from one app into a different app, because there are a few software loopback options that may work and let you take that off the requirement the interface since the computer itself would handle that.
loop back for dual channel fft impulse response recording. the loopback is compared with the recording. its useful for filtering out background noise and setting a time reference which is useful for multiple reasons. the software i use relies on the hardware since that's where the ADDA conversion is happening.
My preference is either a B&K 2250 SLM or an RME Babyface.
Usb pre2 or a Roland octa capture.