# New setup



## yveletnik (Dec 7, 2011)

Hi, a total noob here. Working on my first 'home theater' (read a bunch of speakers in living room). 
My setup Marantz 6005 AVR, comes with audyssey and the setup mic. My laptop sends video/sound via HDMI. Library of torrented lossless Apple music files. Laptop also plays blu rays. Speakers will change, currently Aperion Verus Forte 5.1 set (suppose to be here Thursday).

So i'm trying to achieve following:
1. See how my room treats different frequencies and how will the sound treatment change it.
2. How well the audyssey in AVR fixes the response
3. How different speakers/subs measure in my room

i will not be using any equalizers other than the AVR.
So i was hoping for a simple solution when I can connect my Laptop with HDMI to AVR and generate test signals this way. For the mic I was hoping to use the mic that came with Marantz and connect it to the 'mic in' on the laptop.

I got confused reading about required equipment and not sure if I need all of that to just achieve my tasks.

Like I sad it's a living room and not a dedicated HT, so no need to be absolute perfect in measurements, also maybe there is a calibration file made for Marantz's mic already? and why do I need the SPL meter anyways? the audyssey already set the correct levels on my speakers, I just want to see how sound treatments, different speakers and audyssey itself change the freq response and waterfall charts.


Any input appreciated,
Thanks


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## robbo266317 (Sep 22, 2008)

Welcome to HTS.

I doubt that you can use your mic to do the measurements although others here will be able to either confirm or deny this.

Cheers,
Bill.


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## yveletnik (Dec 7, 2011)

just another fact about my laptop, it has a line-in, i guess. When I connect the mic to the built in sound card, it 's asking me if it's a 'Line In' or 'Mic In' device. And after selecting the 'line in' as device type windows sees a new 'line in' device. So I guess I should be OK in sound card department.

Could someone please explain why using 'Mic In' on the laptop is bad? So i don't try to go this route
Also Why can I not use my regular HDMI connection to send test signals from the laptop to the receiver?

If I understand it correctly all i need now is:
1. the Galaxy CM-140
2. 2 of '3.5mm Stereo Plug To Dual RCA Jack Adapter' to split the right channel on 'line in' and 'line out' of the sound card
3. 1 long cable RCA to RCA male to male for SPL Meter connection
4. RCA Y Slitter for receiver connection to be able to test both speakers

Am I missing anything here?

Thanks for help


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## splatman2 (Dec 28, 2010)

I would think that the mic that came with your receiver is calibrated and setup to only work with your receiver. So putting it in the laptop would not be my first choice and would most likely not give you correct readings of mic positions.


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## aackthpt (Jan 24, 2011)

Actually at LF the mics that come with receivers come out surprisingly good. Check out this thread. But it's still a bit of a crapshoot.

If you have line-in on the computer you can use an SPL meter, but if you plan to use the measurement rig a lot or expect the measurements to be precise, then you should go with a real outboard soundcard/mic pre, measurement mic and mic stand. The EMM-6 is a good place to start for a mic, but order it from user anechoic of Cross-Spectrum Labs if you hope to measure below 20hz, tweak speaker crossovers, or just feel better knowing you have the best accuracy. Also, you will want an SPL meter to calibrate the level on the input side but it's not really 100% necessary as relative measurements are good enough for most purposes. But if you are under extreme budget constraints or already own an SPL meter, then go for it.


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## EarlK (Jan 1, 2010)

> Am I missing anything here?


> You'll need one of these adapters to get signal out of that Galaxy SLM and into your RCA cable .



> My observation ( since I don't actually own a Galaxy CM-140 ) is based on this pic ( taken from the Galaxy 140s' User Manual ). 










> ( Click the pic for the manual ) ;  

:sn:

PS ; Go with the better setup if you want better measurements ( as just mentioned ) .


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## jtalden (Mar 12, 2009)

yveletnik said:


> So i'm trying to achieve following:
> ... and why do I need the SPL meter anyways? the audyssey already set the correct levels on my speakers, ...
> Thanks


If you do decide to go the better route with the measurement mic and an external sound interface you don't need the SPL meter just as you are thinking. Just setup the receiver using Audyssey. That will calibrate the AVR's internal test signal to 75 dB at the LP. Then when it is time to calibrate the REW SPL meter's level just turn on the AVR test tone for one of the channels manually and use that level for setting the REW level calibration. It should have about the same accuracy as using an RS or Galaxy SPL meter with the REW test signal.


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## aackthpt (Jan 24, 2011)

jtalden said:


> Just setup the receiver using Audyssey. That will calibrate the AVR's internal test signal to 75 dB at the LP. Then when it is time to calibrate the REW SPL meter's level just turn on the AVR test tone for one of the channels manually and use that level for setting the REW level calibration.


Whoa, that's a really good workaround!

On my setup I very rarely calibrate the SPL when I make measurements anymore because maximum gain on the hardware knob is the right setting, so as long as I leave the sound card driver gain at 0 I know I have the same gain on the input side as before.


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## yveletnik (Dec 7, 2011)

aackthpt said:


> Actually at LF the mics that come with receivers come out surprisingly good. Check out this thread. But it's still a bit of a crapshoot.
> 
> If you have line-in on the computer you can use an SPL meter, but if you plan to use the measurement rig a lot or expect the measurements to be precise, then you should go with a real outboard soundcard/mic pre, measurement mic and mic stand. The EMM-6 is a good place to start for a mic, but order it from user anechoic of Cross-Spectrum Labs if you hope to measure below 20hz, tweak speaker crossovers, or just feel better knowing you have the best accuracy. Also, you will want an SPL meter to calibrate the level on the input side but it's not really 100% necessary as relative measurements are good enough for most purposes. But if you are under extreme budget constraints or already own an SPL meter, then go for it.


thanks for replies, all

I was about to order the mic+mixer combo from BB, but it looks like the Audyssey mic is just as good (from the article you mentioned) and in that article the guy used HDMI to send test signals. But the only way to connect Audyssey mic to the laptop is with the mic port, not the line in. 
Is there any downside to it?

and then I don't care about true SPL, as long as relative SPL on different frequencies is correct.

So I guess there is no need to waist $100 on something that will not get better result, or am I missing something here?

Thanks


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## aackthpt (Jan 24, 2011)

yveletnik said:


> I was about to order the mic+mixer combo from BB, but it looks like the Audyssey mic is just as good and in that article the guy used HDMI to send test signals. But the only way to connect Audyssey mic to the laptop is with the mic port, not the line in.
> Is there any downside to it?


The downside is that, like any solution that isn't either individually calibrated or toward which you have a lot of data points (in which case you don't know but you can possibly be reasonably certain), you just don't know. You have seen information on one Audyssey mic (or did they test more? I only recall it being one).

In the case of the RS meter, we have data on quite a few (as seen in the cal graph comparison), so we know that it is decent at some frequency ranges, but at others it's quite unpredictable. But the Audyssey mic, given the dearth of data, is simply an unknown at any frequency range.

Any mic will be able to produce data. In REW no one will be able to tell whether that data is garbage or not. The only way to know that is to know what the head end of your input chain is (garbage in, garbage out) and whether it has been checked to a reference. Each of us must pick our own point of comfort with expected quality of the data and our budget. For me, I wanted something known but wasn't willing to spring for the CSL mic at the time so I went for the Dayton mic from Dayton. Your decision may be different and that's OK but you need to understand what you're getting into and what limitations you are placing on yourself in the future by your choice.


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## yveletnik (Dec 7, 2011)

thanks all for answers, I got a new plan. I will get the mic/mixer combo form BB and compare measurements vs the Audyssey mic, I can always return BB items...


I have following in my BB cart:
XENYX 502
ECM8000 - i know it's not calibrated, but I like BB return policy
Hot Wires - 25' XLR Microphone Cable
Scosche - SPL Meter - just to double check REW's measurements

I already have 1/4 TSR to 3.5 tsr + 3.5 tsr cable, I hope i can use it to connect XENYX 502 to 'Line In' on my laptop. is there any point in using the RCA cable? If I understand it right the stereo connectors should work just fine when connected to a mono out on the XENYX 502, Ithink I might have to use the left chanel in REW's setup.

So i guess here is the list of questions:
1. Do I need to buy anything else?
2. Will the cables I have work for connecting XENYX 502 to my laptop?
3. Is it OK to use HDMI to connect laptop to the AVR? I have a feeling it should be a better choice since that's what i'm using to play my music, unless there is some issues with HDMI delay or something like that, total noob here...

thanks for all the pointers, I'll post comparison between that setup and Audyssey mic after I put the whole thing together.


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## jtalden (Mar 12, 2009)

yveletnik said:


> 1. Do I need to buy anything else?


You will need an adaptor and cable to connect the soundcard analog speaker output to the AVR analog input.

[The Scosche SPL meter does nothing regarding "check REW measurements" and is not needed, but you may want it just to set the REW SPL meter level or possibly you have other uses.]



> 2. Will the cables I have work for connecting XENYX 502 to my laptop?


My expectation is:
If you only connect one channel then then it should work fine for standard SPL measurements. 
[The left channel will provide positive polarity and the right will provide negative polarity. The situation will get complicated if you try to connect both channels. 
[I hope someone will jump in if this expectation is wrong.] 

It would be advisable to use the standard recommended wiring to avoid confusion.



> 3. Is it OK to use HDMI to connect laptop to the AVR?


No, I don't think REW will route the test signal to HDMI. You will need to use the analog connections.


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## yveletnik (Dec 7, 2011)

1111


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## yveletnik (Dec 7, 2011)

Thanks everybody for help, I got my ECM8000+pre amp connected and working, here is the comparison of 2 setups:
1. (red)Denon audyssey mic plugged in directly in MIC port on sound card
2. (green)ECM8000 uncalibrated used the file from this forum, no calibration for XENYX 502, not sure if need it. Connected to 'Line In' on soundcard

output goes with HDMI to Marantz SR6005, connected to a pair of $1K Aperion speakers

room is 15x16x8 living room, untreated with regular living room stuff, book shelves, furniture, sofa, Christmas tree


http://www.hometheatershack.com/forums/attachment.php?attachmentid=33994&stc=1&d=1324016782










So the $600000000 question is is Audyssey mic close enough to identify problems in the room and help with positioning speakers or equalization?
Also is there anything in my setup that could compromise the measurements? My suspicion is HDMI connection, although I don't see why it would be a problem.
Also that gradual roll of after 3kHz is it real? or both mics have the same problem with calibration?
Any input appreciated


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## jtalden (Mar 12, 2009)

yveletnik said:


> ...
> Also is there anything in my setup that could compromise the measurements? My suspicion is HDMI connection, although I don't see why it would be a problem.


Me either. It will work just fine.



> So the $600000000 question is is Audyssey mic close enough to identify problems in the room and help with positioning speakers or equalization?


I’m willing answer that for only half price! 
[Actually, only you can really answer that question.] 

Neither mic you used is calibrated. The generic cal file is a reasonable guess for the ECM8000, but it could still be 2 to 3 dB in error from around 10 kHz to 20 kHz if you have one that nears the extreme. 

Cross Spectrum Labs and a German firm have both posted results of their measurements of numerous samples showing the scatter they have found. Check it out.

cross-spectrum.com

diylautsprecher.de

If you decide you would be okay with the accuracy of the ECM8000 and its generic cal, but not with the uncalibrated Audyssey mic, you could (with a 2 or 3 hours of work) create a calibration file for the Audyssey mic using the measurements you made above. That way the 2 measurements would agree very closely on future testing.

The math functions on the All SPL tab can be used to divide the Audyssey mic result by the ECM8000 mic result. That results in a trace that represents the needed cal curve for your Audyssey mic. That curve then needs to be put into a cal file format and loaded into REW. From then on the Audyssey mic measurement using its cal file will match the ECM8000 measurement using its cal file. That doesn’t make Audyssey mic calibration correct it just makes it equal to the ECM8000.

If that meets you need, but you are not comfortable creating the new cal file, I can help you through it or even create it for you.




> Also that gradual roll of after 3kHz is it real? or both mics have the same problem with calibration?
> Any input appreciated


The general trend is real. You should do some reading on the X-curve. 

hometheatershack.com-film-industrys-x-curve-suitable-home-theater.html

The Audyssey calibration targets a modified version of the X-curve. You can read up on that at their site.

Comment:
You indicated above that you wanted to use REW to compare with and without Audyssey EQ to see what it does. Be aware that it’s best to average the REW measurements for the same 8 positions that were used for Audyssey calibration otherwise the results will be misleading.


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## yveletnik (Dec 7, 2011)

Thanks for a great answers, that's what I will do, calibrate audyssey mic to match the ECM8000 and return the Stuff, $100 better spent elsewhere. I'll try it myself and will bug you for help if it does not work.

thanks


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## Jibara (Nov 30, 2011)

Increditable info.


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## yveletnik (Dec 7, 2011)

jtalden said:


> Me either. It will work just fine.
> 
> 
> 
> ...



Calibrating my Audyssey mic to match the ECM8000 worked like a charm, exported the calculated curve into a file with 59383 records and used it as my calibration file for Audyssey mic. Both mics measure exactly the same now, except rare differences that are less than 1Db. So the right thing to do would be buying a calibrated mic, making my existing Audysey mic match that and then returning the calibrated mic. That means no extra equipment is needed whatsoever to get ideal measurements. Or am I missing something here?

Thanks for your help, will need to start working on my housecurve next.


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## jtalden (Mar 12, 2009)

yveletnik said:


> ...
> So the right thing to do would be buying a calibrated mic, making my existing Audysey mic match that and then returning the calibrated mic. That means no extra equipment is needed whatsoever to get ideal measurements. Or am I missing something here?


Well, it's likely you are missing something, but that is for you to determine.


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## FLAudioGuy (Sep 21, 2011)

"So the right thing to do would be buying a calibrated mic, making my existing Audysey mic match that and then returning the calibrated mic."


Does this not constitute a fraudulent return? I would think this is the wrong thing to do. Why not instead rent a microphone from your local pro sound supplier? Or better yet, Linear X has a nice .25" mic model M31 that is cal'd in an anechoic chamber against a B&K 4133. You can make a 9V supply for it quite easily. I have used these mics extensively when I was in the loudspeaker industry. They are very rugged and have several to choose from. Not very expensive for a true lab quality mic. Cheers!


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