Nortec USB microphone

5–6 March 2024. Translated from the Dutch original by the author, using suggestions by ChatGPT where they were usable. And they often were, this time. Well, but it wasn’t really THAT fast after all.

Too soft?

The idea of a USB microphone is: you plug one end of the USB cable into the microphone, and the other end into the computer. Because the microphone is ‘plug and play’, the computer automatically recognizes it as a new device, from which the sound can be captured.

With the microphone I bought and tested, of the Nortec brand (type: 72342/3007855, indicated as the “item no.”), that didn’t work at first: the sound was way too soft. Later it turned out that that was due to a misunderstanding on my part, which I’ll explain further down.

The microphone has a 3.5 mm jack where you can connect earphones. If the USB is also connected, so the preamplifier in the microphone is powered up, you can clearly hear in your ear the sound that the microphone picks up. According to the package and the manual, the frequency range is 30 Hz to 18 kHz, and that’s indeed how it sounds: crisp and clear, with high fidelity.

When my attempts to adjust something in the operating system (especially Lubuntu, but I also tried Windows 10) to get sufficient volume via the USB cable kept failing, I had the idea to use a cable I still had, with a 3.5 mm plug on both ends. One end into the microphone (the jack intended for earphones), the other end into the microphone input of the computer.

That input is then used as a ‘line in’. By adjusting the sensitivity accordingly, i.e. less sensitive than for an unamplified microphone, the sound comes through rather well.

But that can’t be the intended way, can it? Indeed, this is not how it’s meant to be, and it isn’t necessary.

Polar pattern

The microphone is rod-shaped, although that rod is a bit short and blunt. Based on the resemblance with other rod-shaped microphones, for voice or instrument, I thought the greatest sensitivity would be at one end, the opposite end from where the USB cable is plugged in.

With a more or less upright microphone, as shown in the photos, Nortec microphone with pop filter with and Nortec microphone without pop filter without the pop filter, for the best sound you would need to speak into it from above, slightly at an angle. The Directional characteristics Nortec microphone diagram on the box also suggests this: the microphone is upright, with the sensitive area at the top. Click to enlarge the picture; the diagram is located in the top left of the photo, marked “cardioid polar pattern”.

However, this is not the case. The most sensitive spot, where you should speak to avoid noise from other directions as much as possible, is on the side. In the setup of the Nortec microphone with pop filter two Nortec microphone without pop filter photos I took, the speaker should be on the left side, sitting upright with the head slightly higher than the microphone placed with its stand on the table. In other words: the microphone is most sensitive on the side with the green illuminated button for volume control. (In my photos, the button is not green, because I hadn’t plugged the USB cable into the computer when I took them.)

Sensitivity

In Lubuntu, the Linux distribution I currently use (23.10, also 22.04), in the bottom right of the taskbar (which oddly enough is called a panel; isn’t a panel much taller than a bar?) there’s a speaker symbol. When I click on it, above the slider it says “Mixer”. This launches pavucontrol-qt, where pa = Pulse Audio, and vu = volume. Other Unix distributions have the general pavucontrol (which can also be installed in Lubuntu), or something else.

I set the volume on the microphone itself to the maximum, so turned the knob all the way to the right, and then in pavucontrol under “Input Devices”, I set the sensitivity not at 100%, but at 153% (not 0 dB, but +11.08 dB). After starting a recording in audacity, in pavucontrol under the “Recording” tab, the sensitivity of the recording, the so-called “ALSA Capture”, can also be adjusted. If I set that to 153% as well, speaking quietly into the most sensitive part of the microphone produces sufficient volume.

When speaking louder or even shouting, it can become too loud, which can be seen in pavucontrol and audacity. There should be no clipping of course, because that causes an unpleasant distortion. If it happens, one of the three sensitivity settings should be reduced.

The program alsamixer can also be useful. Some of its settings appear to be linked to those of pavucontrol, but not all. I couldn’t get the sensitivity above 100% with it, which is possible with pavucontrol. Sometimes a microphone booster is visible, but then for the built-in microphone of the laptop (which doesn’t need it), not for the USB microphone – for which a bit more sensitivity is desired.

Under Windows 10, I also didn’t see a microphone booster. The signal there was quite weak, but with the correct use of the cardioid polar pattern, it was still usable.

I have never owned an Apple Mac, and I have not tested it with one now either. According to the manual, the Nortec works with Apple and Windows.

Names

On the box the brand name Nortec is mentioned, styled as nor·tec, or preserving the colours: nor·tec. Or is it nor-tec? With a very small hyphen, I think.

Strangely enough, that name is not on the microphone itself, and also in the multilingual manual it is not mentioned anywhere. Instead, the manufacturer is listed as:

Schou Company A/S
Nordager 31
DK - 6000 Kolding

Oh, Danish! I was thinking, could it be something like with jam and such in the supermarket, where the more expensive branded items are made in the same factory as the supermarket’s own brand, which is cheaper but placed on a lower shelf so many customers don’t notice it? At least, it’s sometimes claimed that they come from the same factory. Whether it’s true, I don’t know.

Could nor·tec actually be the famous Danish microphone brand Røde, with nearly identical products, but at a more favourable price? Oh no, that can’t be, because the letter ø (uppercase: Ø) is indeed unique to Danish and Norwegian, but RØDE is not a Danish brand at all. It’s Australian. The name came about more or less by chance, and the Ø in it was intended to give the brand a European flair, and was also as a homage to the partly Scandinavian family background of the company’s founders. But they are from Sweden, not Denmark, and in Swedish they write ö, not ø.

Røde, not to be confused with Rohde & Schwarz.

Moreover, why Danish? On the microphone and the box, and in the manual, it clearly says “Made in P.R.C.” (which of course means ‘People’s Republic of China’) and “Manufactured in China”. So the microphone is not made in Denmark. Or at least not entirely.

Also, pavucontrol does not report the device as Nortec, but as “UACDemoV1.0”. Odd, because it’s not a demo, right? It’s a real working product, sold in stores.

The Linux command lsusb reports “Jieli Technology UACDemoV1.0”. I found Jieli to be a Chinese company, with a website entirely in Chinese. The only thing I can read is in the top left corner: “ZhuHai Jieli Technology Co.,Ltd”.

I find it somewhat messy, all these different names. But who am I? Such decisions are not up to me.

Where available?

I bought my microphone on 23 February 2024, at Dutch shop Action, for 12.95 euros. I recall seeing the same item on that day at webshop bol.com, but for 18 or 19 euros. That price included free shipping. When buying in a physical store, of course, you save those costs. I walked to the store, so there were no petrol or parking costs either.

In my memory, it was explicitly mentioned on bol.com that this microphone was only for PCs, laptops, and desktops, not for smartphones or tablets. Unfortunately, I didn’t make a note of it, and when I search again on bol.com now, I only find this one, for 37.89 euros. That’s quite a big price difference! It now says “For PC Xbox PS4 PS5 Macbook”, and in smaller print: “Compatible with PS5, PS4, Windows, Chrome OS, Mac OS, Smartphone”.

Mine has a USB cable with a B connector on the microphone side, and a type A on the computer side, both with a white speed indicator, meaning it’s not very fast, but then an audio stream doesn’t require spectacular data speeds.

If your device no longer has a USB-A port (the trend is towards USB-C only): adapter plugs are available.

Pay close attention to what exactly you’re buying and what you’re paying for it.

Suitable for musical instruments?

I tested the Nortec USB microphone also with a Spanish guitar, and noticed some kind of clipping, or a cracking or rattling sound. Distortion, anyway. Sounds quite unpleasant. Listen here. Compare a similar recording made with the built-in microphone of the laptop I’m currently working on, an Acer One 14 Z2-485. I don’t hear that distortion in the Acer recording. However, in quiet passages it does have a lot more quantisation noise. But that can be filtered out, with audacity for example. Menu: Effect, Noise Removal and Repair, Noise Reduction, Get Noise Profile, OK.

Well, in fact on the microphone package it says “for podcasting and gaming”, so the microphone is intended for voice recordings, not for singing or playing instruments. That means I’m doing an unfair test. Yet I do find this finding unfortunate, and I wondered what could be the cause of the problem.

Could it be my cheap earphones? But I also played the recording on a good stereo set from the 1990s, with loudspeakers, and heard the same distortion.
Maybe the unwanted sound originated in the guitar itself? Here I made calculations showing that a guitar has a strong resonance around 408 Hz, close to harmonics of the notes I played: G sharp on the E string, and g sharp on the g string. Perhaps that resonance is so strong that something mechanical is triggered on the inside or outside of the guitar?
What speaks against this: I also made recordings of the same notes on a piano, and heard the same distortion.
With expensive condenser microphones, a so-called phantom power of about 48 volts is applied. A USB microphone only has 5 volt available as a power supply. Perhaps that’s why the diaphragms of the Nortec microphone are closer together, to achieve sufficient sensitivity, causing them to touch each other with somewhat louder sounds, resulting in clipping? Counterargument: an acoustic guitar is not a very loud instrument.
I suspect that in the microphone, close to the actual sound transducer, there is a preamplifier, and an AD converter that transforms the analog signal to a digital USB signal. Of course, this has an advantage where noise is concerned: there are no long analog lines that can pick up interference.
Perhaps this preamplifier was made rather sensitive, for relatively weak speech sounds, but as a result, there is not enough headroom, so that with slightly louder sounds, clipping occurs? In other words, the dynamic range of this microphone is quite small, too small for music?
I don’t know.