craiggsmith wrote:For tapping in to the building audio (record out jack), does anyone have a line-level USB audio converter they can recommend?
Here is an example.
https://www.amazon.com/dp/B013E21TUK
The "Sabrent USB External Stereo Sound Adapter for Windows and Mac" https://www.amazon.com/Sabrent-External ... B00IRVQ0F8 can handle a maximum 550mv rms/777mv pk signal before distortion. It can be directly connected to the RecordOut Jack with a TRS cable. It has a MONO mic input and a stereo headphone output.russellhltn wrote:We have a stake conference in a couple of Sundays with a "visiting" general authority. The "ICS Broadcast Planning & Event Support" got in touch with me and in their PDF outlining the setup, they're recommending a "C for Windows and Mac" ............
In testing with my laptop, I've discovered that if I dig deep enough into the settings and turn off "Microphone boost", my "mic input" is perfectly happy with line level.
If this works out, this is a under $20, very simple, it doesn't matter what your laptop has, solution for laptop users.
This is looking like the simplest, easiest, fairly inexpensive ($8 + standard cable) way to get chapel audio to a laptop. Perhaps it should be our "go to" recommendation as it eliminates a lot of variables.CalS201 wrote:The "Sabrent USB External Stereo Sound Adapter for Windows and Mac" https://www.amazon.com/Sabrent-External ... B00IRVQ0F8 can handle a maximum 550mv rms/777mv pk signal before distortion. It can be directly connected to the RecordOut Jack with a TRS cable. It has a MONO mic input and a stereo headphone output.
Bonus! It gives a LAN port, so you can turn off the WiFi. The downside is that's a kluge load of stuff right at the phone.CalS201 wrote:This adapter can also be used on the iPhone/iPad if you have an appropriate "Camera/USB/LAN Charging adapter" like this https://www.amazon.com/gp/product/B08K4L55TL/. If you use this combination you should also connect a charger cable to the Camera adapter because the iPhone, Camera adapter, and Sabrent Audio adapter can drain the iphone battery pretty fast without the charger attached.
russellhltn wrote:This is looking like the simplest, easiest, fairly inexpensive ($8 + standard cable) way to get chapel audio to a laptop. Perhaps it should be our "go to" recommendation as it eliminates a lot of variables.CalS201 wrote:The "Sabrent USB External Stereo Sound Adapter for Windows and Mac" https://www.amazon.com/Sabrent-External ... B00IRVQ0F8 can handle a maximum 550mv rms/777mv pk signal before distortion. It can be directly connected to the RecordOut Jack with a TRS cable. It has a MONO mic input and a stereo headphone output.
Yeah, about $150 for the wireless part. I've been eyeing some Bluetooth transmitters for dealing with phones. I think it would work, but I see some complaints about latency.CalS201 wrote:Attached is a truly universal wireless interface ($$$) that will connect ANYTHING to ANYTHING and has adjustable audio levels and headphone monitoring! We are using this in my son-in-laws stake nearby.
The same company (MOVO) also has a VHF Wireless system for $80. Either way it's not too much to pay.russellhltn wrote: Yeah, about $150 for the wireless part.
Yes, wired is always better if you can do it, and also protect the wires from people walking on them for the next year.russellhltn wrote:In our case, the record out jack is right next to the network jack by the podium, and is connected to PoE port on the switch. I'd rather invest in wired LAN, wired power, and wired sound. Less to go wrong.
russellhltn wrote:Odds are, you'd eventually need wired power to avoid the hassles of charging the battery, so the advantages of completely wireless will be lost. Once you run a wire, might as well do them all.
A wall mounted camera would be a nice permanent solution and would need to be 10-20X PTZ zoom camera ($500-$2000).russellhltn wrote:If streaming settles into being a long-term thing, this is going to be one of the more attractive options. It's either that or the one of the other automated systems that use the church webcast auto-config, although I'd go with a different camera so it could be wall mounted.
A mono "computer" microphone is TRS. Tip and Sleeve has the signal, the ring is power for electret mics. I'm not sure of the details, but apparently, shorting the power to ground by using a TS cable messes up the sound card. Using a TRS cable and leaving the R open on the other end might pick up noise, but otherwise doesn't cause issues.craiggsmith wrote:One thing I wonder about is using a mono vs stereo audio cable. I found two other similar devices on Amazon (https://www.amazon.com/gp/product/B07SSBHGP7 and https://www.amazon.com/gp/product/B01N905VOY) and both say the the microphone jack is not compatible with TS cables, only TRS. Yet it's mono. I can't imagine it expects a balanced input, and even if it did it wouldn't matter if the other channel had no signal. And with an unbalanced mono source it wouldn't matter which cable is used, the ring would just be grounded right. Right?
Sometime I can get specs by contacting the manufacturer, but more often I have to obtain the product and use my signal source, DVM, o'scope and the TrueRTA program to make measurements. The TrueRTA program works great for viewing a waveform (finding the point of distortion), but it's amplitude is not calibrated so I use a DVM or oscope paralleled with the input signal.craiggsmith wrote:Thank you both for the recommendations. Where did you get the specs for the Sabrent device? I can't find max input level for any of the devices anywhere.
A TS cable should be avoided because it shorts the bias or the mic+bias signals to ground.craiggsmith wrote: One thing I wonder about is using a mono vs stereo audio cable. I found two other similar devices on Amazon (https://www.amazon.com/gp/product/B07SSBHGP7 and https://www.amazon.com/gp/product/B01N905VOY) and both say the the microphone jack is not compatible with TS cables, only TRS. Yet it's mono. I can't imagine it expects a balanced input, and even if it did it wouldn't matter if the other channel had no signal. And with an unbalanced mono source it wouldn't matter which cable is used, the ring would just be grounded right. Right?
russellhltn wrote:A mono "computer" microphone is TRS. Tip and Sleeve has the signal, the ring is power for electret mics. I'm not sure of the details, but apparently, shorting the power to ground by using a TS cable messes up the sound card. Using a TRS cable and leaving the R open on the other end might pick up noise, but otherwise doesn't cause issues.
Thanks very much. I didn't know computers were capable of providing power for mics. Since most computers nowadays don't have separate headphone and mic jacks but rather a single TRRS jack, I assume the bias is applied directly to the signal? I certainly wouldn't want to short that to ground at any rate.CalS201 wrote:A TS cable should be avoided because it shorts the bias or the mic+bias signals to ground.
All of the TRS Mic connections I have seen on computers and USB adapters are unbalanced and either
T=mic, R=bias, S=Return
TR=mic+bias, S=Return
T=L Mic+Bias, R = R Mic+Bias , S=Return
If you are running a 50-75 foot TRS cable from the RecordOut jack it would be advisable to put a TS to TRS adapter (mono to stereo) at the RecordOut jack to prevent the "R" from becoming a 50ft antenna for noise. You may not need it but the adapter is only $2 and it's handy to have in your "bag of problem solving adapters"!
Yes, Mic signal and bias voltage both appear on the "S" of a computer or modern phone TRRS jack.craiggsmith wrote:Thanks very much. I didn't know computers were capable of providing power for mics. Since most computers nowadays don't have separate headphone and mic jacks but rather a single TRRS jack, I assume the bias is applied directly to the signal?
The Mic input for the SAbrent USB adapter is a TRS with the following pin configuration:craiggsmith wrote:But this begs the question of what the input looks like for the Sabrent devices. I called them earlier today (they actually have a tech support line and picked up right away) to find out the max input voltage of that other device, but it took them a long time to come up with an answer and they said 3.5V, which seems highly unlikely. So I don't know if they will know the pin configuration or not.
If R is open, then it seems like it should be happy with a TS cable.CalS201 wrote:The Mic input for the SAbrent USB adapter is a TRS with the following pin configuration:
T=Mic+bias voltage
R=open
S=Return
Thank you. Yes, I saw your previous post, I was wondering about the other Sabrent device I listed. I don't like the one initially mentioned as it blocks the adjacent ports unless I buy a separate cable; the one I listed comes with a cable for the same price. But I'm not sure if it's the same internals or not. Most of the description is similar but it also says it "enables PC style 3.5mm headsets with microphone to be used on your Mac." Not sure how you could do that with separate mic and headphone jacks.CalS201 wrote:The Mic input for the Sabrent USB adapter is a TRS with the following pin configuration:
T=Mic+bias voltage
R=open
S=Return
The bias voltage is 3v open circuit, 1.5v when you attach a 10K source, and .5v when you attach a 2K source.
The maximum input is 550mv rms/777mv pk as I described in a previous post viewtopic.php?f=27&t=37755#p215749
Awesome.CalS201 wrote:Sometime I can get specs by contacting the manufacturer, but more often I have to obtain the product and use my signal source, DVM, o'scope and the TrueRTA program to make measurements. The TrueRTA program works great for viewing a waveform (finding the point of distortion), but it's amplitude is not calibrated so I use a DVM or oscope paralleled with the input signal.
I see them from audio retailers but having a hard time finding one on Amazon. I'm only running a 6 foot cable but I'll try to get one eventually.CalS201 wrote:If you are running a 50-75 foot TRS cable from the RecordOut jack it would be advisable to put a TS to TRS adapter (mono to stereo) at the RecordOut jack to prevent the "R" from becoming a 50ft antenna for noise. You may not need it but the adapter is only $2 and it's handy to have in your "bag of problem solving adapters"!
Here you go:craiggsmith wrote:I see them from audio retailers but having a hard time finding one on Amazon. I'm only running a 6 foot cable but I'll try to get one eventually.
Thanks!russellhltn wrote:Here you go:
3.5mm Mono Plug to 3.5mm Stereo Jack
3.5mm Stereo Plug to 3.5mm Mono Jack Adaptor
I have seen variation in signal level for RecordOut jacks in different bldgs. Some are 1v - 1.4v pk for a loud speaker. That's just too high for the USB adapter. You may have to add some attentuation like this -26dv pad https://www.amazon.com/Movo-MV-RC300-Mi ... 073HR6SY4/ and then readjust the computer's input gain. You could also use these volume controls - just realize the female TRS connectors are not the best quality! https://www.amazon.com/gp/product/B00001P4XH/ or https://www.amazon.com/gp/product/B071VL2GF8/craiggsmith wrote:We got the following Sabrent device and used it today. ........ But we still had distortion with louder speakers or those that were very close to the mic.
You need to know the audio "peak" voltage - and keep the peak less then the maximum peak allowed by the USB input (0dbFS). A DVM typically only measures ac rms voltage. Furthemore, you have to be careful when using a sine wave as a substitute for human speech. The peak of a sinewave is 1.41 time higher than the rms , whereas the peak of human speech can be 10 higher then the rms value.craiggsmith wrote:Afterwards I tried to measure the output level with a DVM but couldn't get a good measurement; I might hook up a sine wave generator and measure it this week.
What's the trick with Audacity? I can see when I overload the recording level, but it doesn't necessarily tell me when I overload the input device.CalS201 wrote:If you install and run a program like the free Audacity, or free ORBAN Loudness Meter, they can monitor the USB adapter input using their built in peak meters and easily tell you when you exceed the maximum pk value.
I tested today but forgot to do this, I'll check next time.russellhltn wrote:You might try digging into the control panel settings for the device. I didn't test extensively, but I think I got better results with AGC unchecked. I could not find any setting like "mic boost" I have with my built-in mic jack.
The recording level in Audacity controls the INPUT audio device VolumeLevel setting on the ControlPanel of the computer. If you connect a variable sinewave source to the USB adapter and slowly raise the amplitude, at some point the Audacity input "peak" meter will reach 0dbFS, which is the point of overload/distortion. This can be confirmed using the free "Orban Loudness Meter" program. You can also confirm it with the free"TrueRTA" audio o'scope program that shows the top of the sinewave going flat. Changing the Audacity recording level (or VolumeLevel on ControlPanel) is similar to adjusting the input channel "gain" on a mixer. Finally, if you put an rms DVM on the sine wave source you can read the rms and calculate the peak.russellhltn wrote:What's the trick with Audacity? I can see when I overload the recording level, but it doesn't necessarily tell me when I overload the input device.CalS201 wrote:If you install and run a program like the free Audacity, or free ORBAN Loudness Meter, they can monitor the USB adapter input using their built in peak meters and easily tell you when you exceed the maximum pk value.
I like the ability to monitor the signal with the pad, but it's a bit pricey. I was looking for something with a volume control before, but at this point I would be more inclined to try either the Headset Buddy or that line level USB adapter I found.CalS201 wrote:I have seen variation in signal level for RecordOut jacks in different bldgs. Some are 1v - 1.4v pk for a loud speaker. That's just too high for the USB adapter. You may have to add some attenuation like this -26dv pad https://www.amazon.com/Movo-MV-RC300-Mi ... 073HR6SY4/ and then readjust the computer's input gain. You could also use these volume controls - just realize the female TRS connectors are not the best quality! https://www.amazon.com/gp/product/B00001P4XH/ or https://www.amazon.com/gp/product/B071VL2GF8/
Thanks, yeah, mine only measures rms, it's 30 years old so I was thinking of trying to find a new one that could measure peaks but probably not worth it. I saw up to 700mv with a sine wave so basically 1V. I had my wife sing and she could generate about half that but that's louder than anyone would speak. For now I lowered the input by 10db so we'll see how that goes. I did a test broadcast speaking into the mic very closely and still generated a little distortion, but most people wouldn't be that close. I should have done a test broadcast with different levels of the sine wave to see if I could measure the max input.CalS201 wrote:You need to know the audio "peak" voltage - and keep the peak less then the maximum peak allowed by the USB input (0dbFS). A DVM typically only measures ac rms voltage. Furthemore, you have to be careful when using a sine wave as a substitute for human speech. The peak of a sinewave is 1.41 time higher than the rms , whereas the peak of human speech can be 10 higher then the rms value.
Interesting, I'll have to try that.CalS201 wrote:If you install and run a program like the free Audacity, or free ORBAN Loudness Meter, they can monitor the USB adapter input using their built in peak meters and easily tell you when you exceed the maximum pk value.