Audio via Sound Card Line In and Spectrum Analyzer - Page 1
Forum section: electronics / testgear

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 03:26:53 am
content: Hi,I want my analog audio to be inputted into a PC spectrum analyzer software. What is the best sound card/interface/system that can do this with minimal distortion? Is this related to Total Harmonic Distortion? I don't want the frequency of the original analog audio to be altered. So I want it to pass through the line in and into the PC software itself. If the recording quality of a sound interface or card is good. Does it automatically mean the Line In audio would be good too. What is the relationship between recording and pass through (what is the right term?)And what sound card/interface/system can you recommend? Thank you.

author: Anthocyanina
author_rank: Frequent Contributor
timestamp: July 12, 2023, 03:39:09 am
content: you could try waveforms, made by digilent. i havent tried it with a soundcard, but know it supports it, and it is a really good softwareEdit: disregard, i misread your question as asking for spectrum analyzer software that works with a soundcard

author: dobsonr741
author_rank: Frequent Contributor
timestamp: July 12, 2023, 03:47:29 am
content: I have the Behringer U-PHORIA UMC202HD for this purpose.It has the XCMOS cpu, price is reasonable while the guts are the same as the higher priced ones.Read about the pros and cons here:https://www.diyaudio.com/community/threads/behringer-umc-202hd-for-measurements.341309/

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 04:28:55 am
content: What do you think of the Xtuga E22 2i2 (cheaper than the Behringer) and the more expensive Focusrite Scarlett 2i2 USB Audio Interface (3rd Generation)?So if the recording is good. Pass through via Line In is automatically good?Also if I just use a data acquisition board, can I use any spectrum analyzer software real time? Or does real time only mean a sound card is required? And why can't data acquisition board give real time spectrum analyzing?

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 04:53:10 am
content: Quote from: kirk spec on July 12, 2023, 04:28:55 amIt's not going to make any difference to the spectrum analyzer.Quote from: kirk spec on July 12, 2023, 04:28:55 amYes, but it's not important. Just get one of these if you want perfect passthrough:

author: dobsonr741
author_rank: Frequent Contributor
timestamp: July 12, 2023, 05:12:19 am
content: XTuga is a Chinese company, expect cost cutting and less reliability on the long run. I would bet not having the XMOS cpu in it.You can use other DACs, however these audio oriented ones are having 24 bit ADCs, measurement oriented dacs might not be 24 bit. The audio interfaces expected to be lower distortion, but you need to tell what DAC you are comparing with.Real time vs not is the property of the software, not the hardware. I use REW, and it has a real time updating FFT at 64K points. I also use my own Jupyter notebook to get the same FFT.

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 05:19:27 am
content: Quote from: Fungus on July 12, 2023, 04:53:10 amWhy would the stereo splitter make a passthrough?The inputs are XLR, are they male or female? What XLR brand to get for distortion free passthrough?

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 05:23:29 am
content: Quote from: kirk spec on July 12, 2023, 05:19:27 amI think you're going to have to define "passthrough" for us.

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 05:46:38 am
content: Passthrough means you are not using the sound card recording or playback, but only line in. Meaning your signal is riding in its ADC sampling wave only.

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 06:19:47 am
content: Quote from: kirk spec on July 12, 2023, 05:46:38 amOk. To me "passthrough" usually means it has to go in and back out again to somewhere else. The best/easiest way to do that is with a splitter cable.Any sound card will do, I wouldn't worry too much over that.Start with whatever you've got now and see what happens. Upgrade only if you discover it isn't good enough.For best quality you should probably look for a USB device with separate power supply but that's for later, see above.48kHz is enough and you only need 24 bits if the input signal is very,verylow.

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 07:15:32 am
content: I already ordered the Behringer U-PHORIA UMC202HD just to be sure and not the Xtuga which I almost ordered.But I'm not sure my laptop can power the Behringer. My Microsoft surface laptop can't even charge an IPad 9th gen. Can any powered USB hub do? Or would it introduce noises? What powered USB hubs do you guys use for the Behringer?Also my analog signal can reach 2 to 3 volts. What voltage the UMC202HD Line In can accept?If my signal is 3 volts and I used a resistive divider to make it 1V to match the Line In. Can it distort the frequency?

author: jonpaul
author_rank: Super Contributor
timestamp: July 12, 2023, 08:05:10 am
content: best interface is none...We use a simple 4 cond 3.5 mm male phone to 3x RCA cable.PC is Lenovoo Carbon X1NO amps, sound card, just the PC onboarrd ADC.Free audio SA SW is SoundCard Scope, for speech analysis INFORMANT, RTpitch and RTspect, all free.The best solution is the simplest.Jon

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 08:26:59 am
content: My Microsoft Surface 2017 notebook has no audio input.I found in my things a 4 in 1 Venton USB HUB with mini-usb power supply port (where you plug the 5V adaptor to the mini-usb slot).I just want a rough idea how the USB Hub is able to route the power from the external mini-usb adaptor to one of the USB slot when the slot is already getting power from the notebook USB? Won't the mini-usb adaptor power and notebook usb power collide? I need to know in preparation to power the Behringer.Th

author: jonpaul
author_rank: Super Contributor
timestamp: July 12, 2023, 08:40:40 am
content: Hello again, the old 3.5mm><USB headphone adapters that used to come with Logitech HP 10..20 yrs back had an ADC in the USB dongle.We have many usually free at street and garage sales or with the HP.Fine for most usesJon

author: noisyee
author_rank: Contributor
timestamp: July 12, 2023, 08:50:29 am
content: What's your signal like and what THD performance do you want?Mic-In have a high gain mic-phone preamp which is for very small signal but degradation the system THD performance. Line-In usually mean bypass that preamp and direct feed input to the ADC, which is good for 1 Vrms or 2 Vrms "standard" line level.A typical PC onboard sound card will have better than -50dB THD for mic-in and -80dB for the line-in, which is good enough for most case. But be careful some mic-in have AGC that can not be by-passed, and the frequency response is not that flat (some will have low cut or voice boost).A dedicated sound card will have better performance, and also other feature like variable gain and attenuation setting. Which is good for different signal level.I'd recommend try onboard sound card first to see if it suits your need. Entry level dedicated sound card usually don't have enough performance advantage over onboard sound card. Professional sound card is much much more expensive(almost 1 decade higher).If you really need high performance comparable to an audio analyzer but with budget price, the E1DA Cosmos ADC may be a good choice. It has good reputation among some audio hobbyists.Also be careful with the OS sound mixer, it sometime can ruin your test. If your software support input method like WASAPI or ASIO, the use it rather than DS(DirectSound or System Sound). If not, make sure you have disabled system sound effect, mic-phone boost, noise reduction, etc.

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 09:47:00 am
content: I just cancelled my Behringer order when I heard about the E1DA Cosmos ADC. It has very low distortion which I need. My signal is mainly human voices, I want to analyze voices so I need very clear reproduction without added distortions.Why didn't you guys get the E1DA Cosmos ADC as some kind of sound card? How does it differ to a sound card?Also to evaluate my notebook sound (without any input). First I need to get hold of free PC software audio spectrum analyzers. Please list the free ones that are easy to use and complete. I'm not familiar with Mathlab. Thanks.

author: noisyee
author_rank: Contributor
timestamp: July 12, 2023, 10:06:45 am
content: Quote from: kirk spec on July 12, 2023, 09:47:00 amCosmos ADC doesn't have mic preamp, that mean you just can't plug a mic direct into it. It will not work AT ALL. You will need a separate mic preamp like the Cosmos APU.The functionality of the Cosmos ADC is more likely a audio ADC evaluation board rather than a commercial sound card.Some audio hobbyist mainly use it as a distortion meter to test audio amplifier. The distortion of the Cosmos ADC is over killed for most application.

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 10:27:33 am
content: Quote from: noisyee on July 12, 2023, 10:06:45 amI don't need a preamp, because my line out already has about 1 Volt output directly to Line In of the Cosmos ADC.If the Cosmos ADC has this spec:THD+N 0.00007% @ 1kHz, @ -5dBFS, SR 48kHz, BTW 20Hz - 20 kHz.And it's at $150. Why can't other sound cards more expensive match the spec?And if you have Line Out already without needing any Mic preamp Why can't hobbyists use it as sound card/interface at all?

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 10:45:50 am
content: Quote from: kirk spec on July 12, 2023, 10:27:33 amIt looks like the E1DA Cosmos ADC are already sold out everywhere?https://www.linsoul.com/products/e1da-cosmos-adc?variant=42117413142745They discontinued it somehow? Why?If I get one and connect it to spectrum analyzers, I can get output in real time with the real time input, right?

author: radiolistener
author_rank: Super Contributor
timestamp: July 12, 2023, 10:55:17 am
content: Quote from: kirk spec on July 12, 2023, 03:26:53 amif you don't want to original signal frequency be altered, you're needs sound card with ADC that has good enough dynamic range and linearity.The main parameters which you needs to check is dynamic range (SNR), third-order intermodulation distortion (IMD3) and total harmonic distortion (THD).For a good result you're needs to use professional sound card with very high dynamic range, usually they based on modern 24 or 32 bit ADC which SNR reaching up to 120 dB and even better.For example, if you don't expect very expensive top performance, Creative E-MU 1212M is a good working horse with 24-bit ADC.Avoid soundcard with switching mode DC/DC converters, because they have noise. Also avoid cheap portable USB sound card because they have dirty power and bad filtering and shielding

author: radiolistener
author_rank: Super Contributor
timestamp: July 12, 2023, 11:21:27 am
content: Quote from: kirk spec on July 12, 2023, 10:45:50 amManufacturing such devices is expensive and complicated, it requires manually tested expensive ADC chips which is hard to buy. It's more easy to sell cheap Chinese crap...But you can try Chinese version:https://www.aliexpress.com/item/1005003798311819.html

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 12:11:59 pm
content: Quote from: kirk spec on July 12, 2023, 09:47:00 amThe connectors on the front.The "ADC" part will be the same.

author: Grandchuck
author_rank: Super Contributor
timestamp: July 12, 2023, 12:12:53 pm
content: https://www.eevblog.com/forum/beginners/is-this-a-valid-way-to-measure-thd/msg4951651/#msg4951651

author: dobsonr741
author_rank: Frequent Contributor
timestamp: July 12, 2023, 12:16:20 pm
content: QuoteAny sound input/output on the PC will be real time - they are streams of data with a few millisecond latency.Any good spectrum analysis software will take your real time audio stream, take out the FFT buffer size chunks, do the analysis and refresh your screen. 64K buffer size with 48KHz sample rate it will refresh your display every 1.36 seconds. It’s up to you to define sampling rate and buffer size for the analysis.

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 12:42:32 pm
content: This is the E1DA Cosmos ADC noise floorhttps://linustechtips.com/topic/1400393-e1da-cosmos-adc-noise-floor/What free software can display that too so I can try my notebook internal audio ADC. I tried it on my android cell phone. It needed to have the microphone recording on before the Spectroid app would even run. In the PC/Windows. Do you also need the input on to run it? but the noise floor above was with the input all off. Please give example what you do to get the noise floor in your PC, and the software you used. Ty.

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 12:48:49 pm
content: Quote from: radiolistener on July 12, 2023, 10:55:17 amNot going to fit in his Microsoft Surface.Quote from: kirk spec on July 12, 2023, 08:26:59 amThat's what electronics engineers are paid for.I believe you're over-thinking the sound card aspect. If you want to record human voice the microphone will be orders of magnitude more important than the sound card.Plus: Many voice-optimized microphones come with USB output these days so you won't even need a sound card.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: July 12, 2023, 12:55:59 pm
content: Try Rew to see the noise floor of your laptop ADC:https://www.roomeqwizard.com/

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 01:03:28 pm
content: Quote from: dobsonr741 on July 12, 2023, 12:55:59 pmThat page recommends this calibrated USB microphone:https://www.minidsp.com/products/acoustic-measurement/umik-1I don't know anything about it but it could be what the OP really needs instead of a sound card (or something similar to that)

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 01:50:35 pm
content: The E1DA Cosmos ADC has this spec:Input Range1.7Vrms 640Ω,2.7Vrms 1kΩ,3.5Vrms 1.3kΩ,4.5Vrms 1.66kΩ,6.7Vrms 2.46kΩ,7.6Vrms 2.82kΩ,8.5Vrms 3.12kΩ,10Vrms 3.48kΩ,43Vrms 13.6kΩNote: Unbalanced impedance about 30% less.I know input and output impedance is important due to the idea of resistive divider where the larger value will receive more voltage. How do I measure the resistance above? Is it the ADC input impedance or is it the source impedance of the Line Out?

author: RPP
author_rank: Contributor
timestamp: July 12, 2023, 03:13:29 pm
content: I've been using a Focusrite Scarlett 2i2 with REW, AudioTester and ARTA software for a while now. It works well for me . . .Rich

author: radiolistener
author_rank: Super Contributor
timestamp: July 12, 2023, 03:35:23 pm
content: Quote from: dobsonr741 on July 12, 2023, 12:16:20 pmit depends on the sound card. Professional sound card can support ASIO drivers with low latency down to 2-3 ms. Usual PCI-E sound card has about 100-300 ms latency. Some cheap Chinese sound card can have up to several seconds latency

author: radiolistener
author_rank: Super Contributor
timestamp: July 12, 2023, 03:39:34 pm
content: Quote from: Fungus on July 12, 2023, 12:48:49 pmusb output is a sign that microphone is not professional and has a bad sound quality

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 03:41:02 pm
content: Quote from: radiolistener on July 12, 2023, 03:35:23 pmI really doubt that.

author: radiolistener
author_rank: Super Contributor
timestamp: July 12, 2023, 03:43:05 pm
content: Quote from: kirk spec on July 12, 2023, 01:50:35 pmWith amplitude measurement and using Ohms law. When you connect some sound source to sound input, both have some impedance and your connection turns into voltage divider. When impedance is the same it turns into 1:2 voltage divider, because both resistance is the same.But high impedance is very bad, because higher resistance means worse noise floor due to Johnson–Nyquist thermal noise. This is why hi-end ADC and DAC max impedance is limited to about 2 kΩ max, because they will be unable to keep 140 dB dynamic range with higher impedance.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: July 12, 2023, 03:47:04 pm
content: E1DA impedance: those voltage / impedance values are for the ADC input.What is your source? Voltage level and impedance of the source?

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 03:51:00 pm
content: Quote from: radiolistener on July 12, 2023, 03:39:34 pmYou mean like this one?https://www.shure.com/en-US/products/microphones/mv7?variant=MV7-K

author: radiolistener
author_rank: Super Contributor
timestamp: July 12, 2023, 03:56:31 pm
content: Quote from: Fungus on July 12, 2023, 03:51:00 pmYes, such kind of microphones are intended for these people who like how microphone looks and they don't take care about actual microphone performance specifications and sound quality... Different kind of bloggers, etc...You can find a lot of examples on aliexpress. For example:https://www.aliexpress.com/item/1005005385033091.htmlhttps://www.aliexpress.com/item/1005005145354029.html

author: radiolistener
author_rank: Super Contributor
timestamp: July 12, 2023, 07:00:04 pm
content: Looks like original E1DA store for Cosmos ADC on aliexpress:https://www.aliexpress.com/item/1005003391728199.html

author: kirk spec
author_rank: Contributor
timestamp: July 12, 2023, 10:28:29 pm
content: I'm not sure of the source impedance because this would be related to singing auditions. I'm studying great singers voices for patterns in the spectrum analyzers. Whatever. I want to see for myself.1. My Microsoft surface just doesn't have any line in. Also I bought a cheap USB sound stick before, I found out most usb sound module just doesn't have line in. Do you know what cheap USB stick has line in? While waiting for the legendary E1DA Cosmos ADC from china which can take months to arrive, I want to have a USB stick with Line In first.2. Second. The E1DA Cosmos ADC has low input impedance. Let's say in the future I got source impedance that is very high. It can make the signal in the E1DA so low because of resistive dividing. Are there gadgets where you can decrease or adjust the source impedance to make it much lower so the signal to the E1DA won't be so degraded in magnitude?3. If no cheap USB stick has Line In. I may just get the cheap (compared to the Behringer) M-Audio M-Track Solo first to try. The reason I mentioned cheap is because I can't get 2 $150 units (both Behringer and E1DA) as I need budget for other things. The temporary one has to be $50 or less. What do you think of the M-Audio M-Track Solo?

author: noisyee
author_rank: Contributor
timestamp: July 13, 2023, 01:46:27 am
content: Quote from: kirk spec on July 12, 2023, 10:27:33 amCosmos ADC use a new released ESS ES9822, while other sound cards use very old AKM, CirrusLogic, or TI parts. It will take a long time for a new part to hit the market. Also the ES9822 is quite expensive, don't expect it appear on a cheap sound card.Most hobbyists would use their sound card. Like I said, the Cosmos ADC is over killed for most application, so only those guys who are really serious about THD but can't afford the expensive Audio Precision would use Cosmos ADC.Quote from: radiolistener on July 12, 2023, 10:55:17 amYes E-MU 1212M is a good alternative for a quite good performance without spending too much.Quote from: kirk spec on July 12, 2023, 01:50:35 pmIt's the Cosmos ADC input impedance. Due to it full differential amplifier input architecture, the input impedance is not high enough. It's a tradeoff between gain setting resistor and noise.Quote from: radiolistener on July 12, 2023, 03:35:23 pmIt also depends on hardware driver. Intel Ethernet card driver will cause a very high DPC Latency, a bug last for several years.Use DPC Latency Checker to see if you are affected.Quote from: kirk spec on July 12, 2023, 10:28:29 pm1. As far as I know, no.2. You need a buffer amplifier. Most high impedance audio source comes from mic, so a mic phone preamp may do the job.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: July 13, 2023, 03:45:27 am
content: M-Track Solo looks OK for a single singer mic recording. With the mic preamp and phantom power you are covered for most of the professional type mikes.

author: kirk spec
author_rank: Contributor
timestamp: July 13, 2023, 04:51:13 am
content: How does the preamp of the M-Track Solo compared to the preamp of E1DA Cosmos APU?https://www.linsoul.com/products/e1da-apu-cosmosMaybe getting both E1DA Cosmos ADC and E1DA Cosmos APU would be the best of both worlds? Why not?

author: Fungus
author_rank: Super Contributor
timestamp: July 13, 2023, 05:07:50 am
content: Quote from: radiolistener on July 12, 2023, 03:56:31 pmSo you're painting the $250 Shure with a $12 Aliexpress brush? Got it.

author: kirk spec
author_rank: Contributor
timestamp: July 13, 2023, 06:40:00 am
content: My usb sound stick only has microphone and headphone output in the Windows Surface notebook that has no microphone input at all. Is there any device available so I can use my friends line out gears on the USB audio stick? Something that can decrease the 1 Volt Line Out output back to millivolts so the Line Out can be inserted into the microphone input? What do you call such device?

author: kirk spec
author_rank: Contributor
timestamp: July 13, 2023, 07:59:37 am
content: About 2 weeks ago I ordered a data acquisition module from china in order to get it to accept Line In and get the audio displayed in the spectrum analyzer and learn the secrets of great singers:I'm doing some reading the past hours. The ADC in it seems to be based on the imposing ARM32 (very military sounding) and have 5 Mega samples per second. So it's like 5Mhz sampling versus the audio 44.1kHz?What do you make of it if the data acquisition module would be used as sound board? The sampling is 26 times better than 192 kHz. What would Mariah Carey sound in the data acquisition board?Also I presumed Audacity can display the above module data real time but at 5 Megahertz?

author: kirk spec
author_rank: Contributor
timestamp: July 13, 2023, 09:43:46 am
content: Quote from: noisyee on July 13, 2023, 01:46:27 amWhat is the equivalent of the E1DA Cosmos ADC in the Data Acquisition Devices (DAQ) world? Does DAQ need also very flat THD? And if DAQ has flat THD the same as the Cosmos ADC, then the DAQ can equally work for audio too?

author: uktony
author_rank: Contributor
timestamp: July 13, 2023, 10:26:49 am
content: After a lot of testing and experimentation, I'm currently using an Asus Xonar STX card for audio testing. The Asus Xonar DX is a lot cheaper and also gives very good measurements.Another ADC I'm using is an Olivine 2 from Altor Audio which is useful for portable measurements (it's a USB device with isolation)https://www.altor.co/products/test-equipment/olivine-2-adcThere are other better options out there, such as the E1DA Cosmos ADC mentioned previously in this thread.I built a front end buffer / gain stage which plugs into the input of my sound card (and also provides a measure of protection for the sound card) and I use a custom built Crystal CS 4398 DAC as a signal generator, using the WaveGene signal generator software.The software I use for measurements is WaveSpectra and Virtins Multi Instrument.It's all documented on my website here ->https://gtkc.net/audio-test-and-measurement-for-diyI hope this info is useful.This is a screenshot of Virtins Multi Instrument software, showing a typical measurement.