Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How... - Page 15

Not at all upset with you. Just annoyed that this is getting more complicated than I was led to believe. I went from having a simple answer that no additional equipment would be needed beyond the USB mic, and I could use standard analog audio output to generate the test tones, to your response, thus it feels like it's going backwards.

As I understood it, the audio output portion (HDMI vs. whatever) was secondary; the initial impetus was about the INPUT portion, i.e. the USB mic obviating the need for additional gear (external soundcard, phantom power, etc). The HDMI output aspect was secondary "gravy" for people who were fascinated by the idea of being able to ping each channel individually. But when jevansoh originally introduced the topic it was not limited in scope to the HDMI output option; the specific form of signal generation wasn't really relevant. I don't know at what point the two merged but when it was initially discussed in the Audyssey thread the two were NOT linked.


Not sure, but maybe it was the part where Jason explicitly said that was the case when this was initially being pitched in the Audyssey thread?


So, yeah, I think that was a reasonable inference on my part.



Well I guess you missed this exchange. It's disappointing to me that the scope has narrowed from the original introduction in the Audyssey thread such that it's now exclusionary towards those who don't have the HDMI output option.

Again, I don't understand why the OUTPUT aspect has to be linked with the input side. It's almost certain that I am misunderstanding something, but I though the biggest revelation of the process was the support for PnP (or almost) USB mics making the intro to REW much more accessible. What does it matter how the funny test tone sounds gets from the laptop to the speakers? If the speakers make noise, can't you measure it?


OK, that's all warning about the mic INPUT portion. That's the part that is now obviated by the USB mic (as I understood it). All I'm talking about is the sound OUTPUT, the signal generation portion.

I'm not trying to be a dick, and I truly don't understand enough about the topic to know where I'm going astray, but I feel like what you are telling me does not jive with what was originally discussed during the genesis of this idea in the Audyssey thread.
Edited by batpig - 1/17/13 at 10:56pm

FWIW, BP, I am confused too and, up to this point, thought the same as you did - that if you had the USB mic all you needed were some additional cables - HDMI or RCA as preferred,

+2

@batpig:

Excerpts from REW legacy setup page:

"Important notes:

You will require a soundcard with a line-in and a line-out jack.
A microphone input (mic-in) on a soundcard is not suitable (many laptops only have mic-in).

LAPTOP Note:
If your laptop is limited to a mic-in port with no line-in, then you'll require an external USB soundcard. "

REW Cabling and Connection Basics"


Example of a simple and inexpensive external USB soundcard: Behringer UCA-202

That's about it.

 

That is for the 'old' REW. The version of REW batpig (and the rest of us in this thread) are using does NOT need a separate soundcard if used with the USB mic. This post from Jason clarifies it:

 

 

"There are no other "black boxes" needed. You will NOT need a full duplex sound card because you aren't using the sound card's mic input and speaker/line output at the same time, as you'll be using the USB Mic. So the built-in sound card that every PC/Laptop has works fine. (Using it this way myself on a cheap laptop)

 

Yes, the output/jack on the sound card is 1/8" stereo mini and Yes, the input on the AVR is RCA, but that is taken care of by a $3.00 1/8" to RCA Splitter/Y-Adapter that I bet most of you already have."

 

It is the same thing. You can use either. 

 

This:

 

 

 

Connnected to two RCA male-male cables .... is exactly the same as this:

 

 

 

 

 

... which is, I think, what you asked. All discussion of 'legacy REW' and external soundcards is irrelevant because you will be using the USB mic which uses the laptop's internal soundcard (which is also the point of this thread as you pointed out somewhere). Phew!

 

I think you answered a question he didn't ask, Jerry. All baptig is asking is how to connect the cable between the laptop headphone jack output and the AVR RCA AUX input. AFAICS, 'legacy' doesn't come into it.

Sorry this has become so frustrating, and that I have added to the confusion. BP, thanks for quoting those posts by Jason--I guess my recollection was flawed. HST, Keith has answered your cabling and connection question. Now all that remains is to get the USB mic, and you should be good to test it out. Without the USB mic's, we are all still in uncharted territory.

Hope I'm not simply repeating what has already been said, but here goes:-

For PC output to AVR input, the PC headphone/speaker jack via any lead that converts 3.5mm to RCA will be fine.
For temporary use of the Audyssey mic, the PC microphone input will be fine.

If you want to use the REW Timing Reference loopback system (to accurately measure time delays/impulses, etc) you will need to feed an AVR pre-amp output back to the PC - but you can't use the microphone input due to its high gain, and DC voltage output (to power the microphone capsule) that's where the external USB sound card come into the equation (they have line level inputs - with no DC voltage output)
Most of the people on the REW forums are using 'proper' microphones that require Phantom power and a pre-amp (similar to Audyssey Pro?) and then the mic pre-amp feeds the line level input of an external soundcard (again NOT the mic input of a PC). The interconnection systems they employ are also configured to provide permanent loopback (hence the adaptor and cable recommendations)

Regards, Mike.

If that works out, then that is the simplified basic REW setup. I have a duplex soundcard in my PC, but I am considering buying the USB microphone due to the simplicity of the hookup.

Let me share my experience so far - based on Batpigs initial question regarding using a netbook to take advantage of the new REW USB microphone capability, and the subsequent positive response that it was possible to use a netbook with this configuration, I purchased a used Dell Mini 1010 Netbook with HDMI on eBay, and thanks to Austin Jerry's very helpful step by step directions entered the rabbit hole. To be clear, my only previous measurement experience involved taking Audyssey measurements on my Denon 4311. I am at the point in Jerry's setup manual where you test the REW Timing Reference loopback system - and so far, despite several hours, and assistance from Jerry, I am unable to connect and get a valid measurement. I have loaded REW and ASIO4ALL successfully, and completed all the setup steps in Jerry's setup guide up to the REW Soundcard Calibration (page 34-35) This step requires sending a signal from the Netbook(laptop, etc) via microphone jack/RCA cable to the AVR preout - I continue to get clipping messages indicating that the measurement is invalid. Efforts to reduce/increase the microphone volume have had no impact on the outcome.
So my experience seems to confirm AV Mike's comment that you can't use the microphone input due to it's high gain, and therefore an external soundcard and "proper microphone" is required. I would hope that this is not the case - but my experience seems to indicate that it is. Has anyone successfully configured a netbook/laptop with HDMI capability using Jerry's guidelines? Are there other steps, techniques that are suggested? Any input is appreciated!

 

:)  You can say that again!  And we're in a sort of limbo now as well, till the mics arrive. You guys will get yours at least a week before I do due to postal delays in getting mine to the UK. I am *very* much looking forward to the posts that will be made in that interval ;)

 

It definitely works with HDMI as several of us have tested it already, using any old mic (or in my case my OmniMic USB mic) just as proof of concept. Of course there's no point taking real measurements until we get the proper calibrated USB mics, but it certainly works and is definitely simpler.

 

The author of REW has made a preconfigured setting in the latest beta of REW for the UMIK-1 USB mic and has, AFAIAA, confirmed to Jason that the soundcard calibration can be performed the way Jerry describes. If an external soundcard was needed, then there isn't really any simplification and the purpose of REW 5 beta is negated. HST, I have not tried to calibrate the soundcard following Jerry's instructions as I was waiting for my 'proper' mic to arrive. I will try to do this over the weekend using my OM USB mic as a test instrument and will report back.

Thanks Jerry, and again to be clear I was never angry/upset with you. I just became frustrated because I felt like was asking a simple clarification question about step 5 in a process, and then was being told, "sorry, actually you have to go back to step 2!"

Can someone explain then what functionally is lost by not being able to access the Timing Reference loop back functionality? Does that render REW useless or does it just limit what measurements I am able to perform? e.g. maybe I can't test impulse response but I can still do frequency response, waterfall charts, etc. Please spare no effort in keeping it very dumbed down for me as I try to grasp these basics

I have a UMIK-1 on order, and understand that the soundcard calibration will be loaded in REW - hurray! I was under the impression that I could "play" around with REW prior to receiving the UMIK-1, but apparently the limitations of my current microphone configuration will not let that happen. I'll stay tuned, unless any one can suggest any intermediate steps prior to loading the UMIK calibration.

I repeat my original statement--we are in uncharted territory until we get our USB mics.  I would not fret about not being able to get the interim solutions working.  If I interpret Jason's posts properly, until a USB mic is connected, you will not be able to use the line out/mic in on a typical laptop for full REW functionality.  ICBW.

 

Hop diggity dawg... would you believe it?  I don't have (or can’t find) the 3.5mm to RCA adapter that I need to do the soundcard calibration test I said I would do this weekend. I have ordered a new one from Amazon but it won’t be here till next week now... darn...

You can pick one up from Radio Shack or Guitar Center near you.

Don't know that they have those everywhere in merry old England.


Max

Oh, I forgot he is in UK. I think they closed all the Radio Shacks that used to be there. I can't stand Curry's but if there one near him, they seem to have something close to get him by: http://www.currys.co.uk/gbuk/logik-3-5mm-mini-jack-to-2-rca-audio-cable-1-5m-07059827-pdt.html

It is a cable and rather short but he may be able to get extenders. And or find the adapter in person as their web site search capability stinks.

 

True - but the main reason is that the country is now paralysed as a result of a few inches of snow. Roads are blocked, airports closed, trains cancelled. UK infrastructure spending is very low and the result is third-world levels of public services. /[rant]  Not to mention I live miles from anywhere in the middle of open countryside.

 

So hopefully Amazon will deliver one to my door and I will be able to do the test next week.

I have seen several notes regarding the cable/plug to convert the stereo mini-jack to dual RCA connectors. However, I haven't seen anyone mention what is required at the other end of the connection.

Keep I mind that REW outputs a mono signal. So, on one end of the connection between the laptop and the AVR is the stereo mini-plug to RCA converter that we have been discussing. To this, you need to connect a single RCA cable of the appropriate length to reach the AVR. On the AVR-end of this cable, you will need a simple RCA Y-cable, which you will use to route the mono signal from REW to both the left and right RCA AUX inputs on the AVR. IOW, don't forget the Y-cable.

OK, so now we can route back to my original question which started this discussion:

Isn't the simple male>male 3.5mm to stereo RCA y-cable sufficient?




My understanding was that, with this cable, you plug into the left RCA AUX input to test the left front speaker, the right RCA AUX input to test the right front speaker, and BOTH of the AUX inputs (with PLII Cinema enabled) to test the center channel speaker. Is my understanding correct?

For the sake of the this thread someone please confirm!!! I would like to know too

Well I've been using the same cable for about a year, treating it as mono. REW input/output 1 is Left. With both RCA plugs connected (left & right), you use the Timing Ref Output to drive the "other" channel.
Regards, mike. (Sorry for lack of detail, sick in bed at present) - where's Jason when you need him?

Not quite. If you use the cable above, only the right channel, I.e. the red cable, will carry a signal (recall that REW is a mono signal). So, you would plug the red cable into the right channel input on the AVR to measure the right channel, and move the red cable to the left input on the AVR to test the left channel. However, to test left+right, you need to plug the red cable into a Y-cable, and feed both the left and right AVR channels simultaneously. Setting the AVR to PLII Cinema will combine the left and right signals and output to the center channel.

Does this clear it up?

Yes it does! Thank you!!

Silly me, the reason it wasn't clicking was that I assumed the mono signal output would be dual-mono, not just isolated to one of the RCAs. Cheers!

Couldn't you use "Stereo" mode?

Not for the center channel!

In terms of the FR/FL, with a single mono input (i.e. right channel only) the STEREO mode will only play out of the right speaker because there is no signal info in the left channel.