Audio Interface for IEMs, Dynamic Mic, and Speakers

[spicysauce]

Hi everyone, I am using a PC and fairly new to the audio world, still learning about how things work, though I have invested my money for some gear like a dynamic mic (maono pd400x), speakers (presonus eris 4.5), and planning to buy a decent IEM (Truthear Hexa) for gaming and listening to music, but before I buy the Truthear hexa, I have here a budget IEM (CCA CRA) and when I connect it to my dynamic microphone which is currently USB powered, I'm hearing a subtle distorted static sound but when I connect it to my speakers headphone port, I don't hear any static sound. It bugs me a lot when everything is quiet I really can hear it.

Due to this reason, I'm considering on investing in an audio interface, I've done some research and watched YouTube videos about interfaces and picked Audient ID4 mkii and Motu M2.

Reasons why I picked them:

1. Audient ID4 mkii - I really like this interface, also the design with the mic xlr input is at the back, love the feature of having a monitor mix included. But they say that this interface is only for high impedance headphones. Saw the review of Julian Krause, does the headphone ohm or whatever can really affect the sound of IEMs? Will I notice it? Really don't know about all these, but I've searched that the Truthear hexa have an impedance of 20.5Ω土15% @1kHz.
2. Motu M2 - I saw that this interface is good for low impedance headphones and overall performance is good which I really like, also have a dedicated knob for headphone monitoring, but when I searched for reviews on the internet, I saw that there are a lot of driver issues with PCs. So I really don't know what to pick and what I need.

I've been digging around these for almost a month now, so please help

P.S.
I've tried using my friends Scarlett Solo, it's great but one thing I don't like about it doesn't have a knob for headphone output, just a button for direct monitoring. Haven't tried the 2i2 and question about the knob for audio monitoring, is it like a Monitor mix? or just a volume for the mic?

 

[Dunring]

I've had the Hexa and used them for a week or two. I'd highly recommend the Simgot EA500 with Dunu S&S tips which I use for a daily driver now and would never sell. Even an Apple USB-3.5mm adapter will more than power them. They need a little more than a phone or onboard sound to shine, but not much more. If the Scarlett is just missing a volume wheel for headphones, there are inexpensive USB volume control wheels available. I got one on Amazon and it works great, and some are programmable too.

 

[DVDdoug]

when I connect it to my dynamic microphone which is currently USB powered,

That's confusing. Dynamic mics don't require power. Of course if it's a USB mic, the built-in preamp & ADC do need power.

USB computer mics (and analog computer mics) are not compatible with audio interfaces that have balanced XLR mic inputs. With a USB mic, the "interface" or "soundcard" is built-into the mic. There are a few mics some mics with both XLR and USB connections.

Almost all analog "computer mics" are electret condensers and they get 5V power from the soundcard. Studio condenser mics get 48V phantom power from the interface, preamp, or mixer.

Many interfaces don't have quite enough gain for dynamic mics (depending on the loudness of whatever you are recording). Studio condenser mics have higher output. A lot of people with dynamic mics end-up using a "cloudlifter" or similar, which is basically a pre-preamplifier.

I'm hearing a subtle distorted static sound

USB power tends to be noisy and sometimes that noise gets into the analog section of a USB powered interface. That's mostly an issue with the mic preamps because any noise gets amplified. Usually it's a high-pitch whine. Then you don't know if you should blame the computer or the interface... An interface with its own power supply can avoid that particular problem.

You shouldn't get (audible) distortion unless you overdrive the ADC into clipping. Or super-loud sounds can push the head-amp in a condenser mic into clipping. (Some condenser mics have a "pad" switch to knock-down the signal.)

And most interfaces don't have anything special for the headphone amp. It's mostly for monitoring while recording. But it may be perfectly adequate depending on your needs.

 

[spicysauce]

That's confusing. Dynamic mics don't require power. Of course if it's a USB mic, the built-in preamp & ADC do need power.

My bad about that, I meant to say it's connected via USB.

There are a few mics some mics with both XLR and USB connections.

That's what I currently have. I decided to have both usb and xlr connections in a mic since I want to upgrade to a good gear sooner.

Usually it's a high-pitch whine.

I think this is what I'm hearing. Because when I tried using the mic with my friends scarlett solo connected via XLR I'm not hearing any high-pitched whine on the iems.

What interfaces do you recommend?

Thank you for your reply! Did learned something today, I just want something clean to listen to that's why I'm looking for gears to make it sound better and clearer than hearing hiss on any iem.

 

[AnalogSteph]

When it comes to picking audio interfaces, YouTuber @Julian Krause is your man.

CCA CRA seems to be an inexpensive dynamic driver IEM, 34 ohms, 105 dB/mW (~120 dB/Vrms, not super sensitive). I don't honestly think it would be too picky. There is almost no interface with a higher than -100dBV output noise floor, dynamic driver IEMs tend to have a very flat impedance response so output impedance would not be very critical either... channel balance at low volumes could still be. The Truthear Hexa as a multi-driver affair at 20.5 ohms would probably be a lot more impedance-critical, even if sensitivity does not differ much (120dB/V spec).
Let's see:

Hmm, that's a bit dire. The CRAs would likely be happy with most of these, but the Hexas would probably not sound quite right at >10 ohms of output impedance, which would rule out a majority. You may have to splurge on the MOTU M2 (I suspect some of the driver issues may be general PC issues with USB, AM4 systems used to be notorious for this before a round of BIOS updates mostly fixed them), or - Plan B - run an otherwise decent interface's headphone out into an external headphone amplifier via a corresponding cable (think Sabaj A10h, JDS Labs Atom Amp+, Schiit Magni Heresy, Topping L30 (II)). Then you'll definitely have a headphone volume knob. Total cost would generally be similar for both, assuming you're going with e.g. a Scarlett Solo 3rd gen which is quite inexpensive right now (or a Presonus Audiobox GO or perhaps a Behringer UMC22).
Plan B could be a good bit cheaper if say you're going with an M-Track Solo + A10h, but you are compromising on build quality at that point. Perhaps your friend would be willing to part with the Scarlett Solo at a decent price and upgrade?

PD400X specs don't explicitly say what impedance capsule they use, but given the -51 dBV/Pa sensitivity spec and that most inexpensive dynamic mics use 600 ohm capsules, it's probably one like that. An input for that needs to have decently low EIN but nothing spectacularly low is required, after all the physical limit is -124.9 dBu (20 kHz unweighted) or -127ish dBu(A).

So basically, avoid the handful of yellow / red ones (as well as dubious nonames) and you should generally be fine.

 

[spicysauce]

CCA CRA seems to be an inexpensive dynamic driver IEM

This is my current IEM! Got it from Crinacle .

The Truthear Hexa as a multi-driver affair at 20.5 ohms would probably be a lot more impedance-critical

Yeah, I've done some searching and I'll pass on the hexa, eyeing out for the Dunu Titan S next. Just want to take may gear to the next level first before I buy a new IEM because I don't want to hear any hiss or static with new IEMs . I do want to invest in Headphones most especially the M50x, but my head hurts from headphones the longer I wear the, that's why I'm leaning towards IEMs, but the low impedance and other things are killing me, never new audio would be this complicated.

You may have to splurge on the MOTU M2 (I suspect some of the driver issues may be general PC issues with USB, AM4 systems used to be notorious for this before a round of BIOS updates mostly fixed them)

Actually, Motu M2 was the first in my list, but then I've seen a number of people complaining about the drivers in Windows and that was exactly what I feared because if it wasn't for the problems I've seen regarding the drivers, I'd have already made my choice. Next is the Audient ID4 for their great mic preamps, but the Headphone output impedance is 22 ohms. My friend's Scarlett had some issues already with the volume knob, while turning I'm hearing some crackling sound and distortions while something is playing, that's why I won't take it. Focusrite just released a new generation of Scarlett interfaces and looking at the gen 4 solos but they have 50 ohm impedance. Also while at it, I've seen some Youtube videos like Optimum Tech's, he used the Evo 4 for low impedance headphones which have 22 ohms @ 1khz, so I thought it's alright to buy the Audient ID4 for my current setup. Then I stumbled upon some reddit comments that the general rule for impedance in headphones is the rule of eight. I really don't know what I got myself into! Audio gear is hella complicated.

Might consider the Magni, just need to decide whether I'm satisfied with the USB mode of my mic. BTW, my mic have both USB and XLR, does the difference of connected via USB that big from XLR?

From the table you've sent, does the output power into 16, 32 means that they are good at that certain headphone ohm/impedance?

Sorry for noobish questions, and thank you for your replies!

 

[AnalogSteph]

Actually, Motu M2 was the first in my list, but then I've seen a number of people complaining about the drivers in Windows and that was exactly what I feared because if it wasn't for the problems I've seen regarding the drivers, I'd have already made my choice.

Don't you have the option of sending it back without much hassle in case it should not be to your liking? Then I wouldn't just chicken out before you've even tried it.

Reading through the reviews at Thomann, it seems you have a greater chance of needing an active USB hub for stable operation than running into actual driver issues (although they do seem to have a few quirks).

BTW, my mic have both USB and XLR, does the difference of connected via USB that big from XLR?

Depends. The USB part often seems to be a bit light on bass in comparison, due to what I assume is smallish coupling capacitors. My Samson Q5U was like that, too. Perhaps the idea is keeping bass levels low so you can get away with relatively modest ADC dynamic range more easily. If you've ever played around with mics sporting good bass extension, you'll have noticed that you can generate some major bass peaks when bumping the mic and such. This content in relatively unimportant frequency ranges could really disturb the important stuff when it clips the input.

From the table you've sent, does the output power into 16, 32 means that they are good at that certain headphone ohm/impedance?

You have to look at both the output power provided and the 300 mV / 32 ohm THD+N column (the one right next to 600 ohms). Just from available output power alone, you'd say that e.g. the 3rd gen Scarletts are decent at driving 32 ohms... until you look at the distortion performance. I guess they're actually still OK for IEMs, but not so much for full-size 32 ohm cans of the less sensitive kind.

 

[Dink]

Scarlett Solo 4th Gen is a good solution for you, which has a knob for headphone output.