# Tascam 122 MKII setup



## THX-UltraII (Nov 19, 2008)

I m going to use the Tascam 122 MKII with REW (+cross spectrum ECM8000). Can someone tell me step-by-step what I need to do for the Tascam to get it working correct with REW. The hardware (cabling) setup is already done: ECM8000 is connected to xlr R input of the Tascam and rca R output of the Tascam goes to my aux R+L input of my receiver (Marantz SR5005). What I need to know is what I have to do with:

- the mon mix (input/computer) knob
- the phones/line out knob
- the input R mic (line/mic) knob
- the mono switch (on/off)
- the phantom switch (on/off)
- the mic/guitar switch

After you guys help me on my way with this I would also like to know WHAT to do exactly with the Tascam BEFORE i start making measurements in REW. Do I need to calibrate it or something?

Thanks in advance guys!

Greetings Sander from the Netherlands.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> - the mon mix (input/computer) knob
> - the phones/line out knob
> - the input R mic (line/mic) knob
> - the mono switch (on/off)
> ...


The PHONES/LINE OUT knob controls the volume to the headphone jack, and the main output level as well. You will have to tweak this to get the proper levels for REW.

The MONO mix probably should be off. I expect it combines the Left and Right input signals.

INPUT- R Mic/Guitar switch changes the right input for a signal from a guitar or one from a mic. The knob adjusts the gain for the right input signal. You’ll have to tweak this (or the left Input knob, if you chose to use that channel – no, it doesn’t matter which one you use) to get a proper level for REW, but you do not want to see the SIG/OL light turn red. I’d recommend keeping the input level high (get the SIG/OL light to turn red then back the knob down a bit), and then use the PHONES/LINE OUT knob to adjust the final signal to REW.

The PHANTOM switch should be on – it powers the mic.

The MON MIX knob should be fully panned one way or the other. I can’t remember which way. However only one way will work, so it shouldn’t be hard to figure out.

You can perform a calibration on the TASCAM, but it really doesn’t need one. It’s ruler flat and down only ~1/2 dB at 20 Hz.

Regards, 
Wayne


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## THX-UltraII (Nov 19, 2008)

ok, so:

1. MONO switch to OFF
2. PHANTOM switch to ON
3. MIC/LINE or GUITAR switch to MIC/LINE
4. MON MIX knob to either all the way to the left (INPUT) or right (COMPUTER), I ll have to figure this out (will I hear distortion or something or will it just not give a signal you think?)
5. set INPUT RIGHT knob to a point where the SIG/OL led becomes red and then turn it down like 10% or so. After this do:
6. set the PHONES/LINE OUT knob to ?? (you will have to explain to me what the signal is that REW needs so on what value I will have to put the knob on).

thxz


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## Wayne A. Pflughaupt (Apr 13, 2006)

THX-UltraII said:


> 6. set the PHONES/LINE OUT knob to ?? (you will have to explain to me what the signal is that REW needs so on what value I will have to put the knob on).


REW has its own input level adjustment, on the Soundcard page. If you can’t get enough signal there, then increase the TASCAM’s Line Out level. I’d suggest starting with the TASCAM’s Line Out maybe half-way up. :T

Regards, 
Wayne


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## THX-UltraII (Nov 19, 2008)

Here s a dumb question I think Wayne. I ll come back to point 5 (set INPUT RIGHT knob to a point where the SIG/OL led becomes red and then turn it down like 10% or so) for this:

WHAT do I do exactly to get this SIG/OL led become visible? Is it the 'CHECK LEVELS' option in the soundcard preferences I have to run?? :huh:


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## Wayne A. Pflughaupt (Apr 13, 2006)

THX-UltraII said:


> WHAT do I do exactly to get this SIG/OL led become visible?


Plug in the mic and give it a signal. Like perhaps play some pink noise through your system at something between 75-80 dB.

Regards, 
Wayne


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## THX-UltraII (Nov 19, 2008)

Can I download a pink noise somewhere?


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## EarlK (Jan 1, 2010)

Hi,



THX-UltraII said:


> Can I download a pink noise somewhere?


There's no need to use an external Pink Noise file .










Use REW(s) built in Signal Generator. 

It will output ( through your soundcard ) 2 variations of Pink Noise ( among some other types of test signals ) .

Choose, "Pink PN".

:sn:

PS : I'm really quite surprised you aren't already aware of REW(s) signal "Generator" .

After all, more than a year ago you were already successfully running REW with a different hardware setup (ie; Xenyx 502 with UCA202 soundcard ) .










Your data capture of your Velodyne DD18 is seen here ;

























From  *this thread !*  and  *this one !*


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## Wayne A. Pflughaupt (Apr 13, 2006)

What Earl said.  But if for some reason you really need an external pink noise source, click the link in my signature and you’ll find an article on gain structure. In it you can find a pink noise signal you can download.

Regards, 
Wayne


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## jianhua1975 (Sep 13, 2011)

THX-UltraII said:


> ok, so:
> 
> 1. MONO switch to OFF
> 2. PHANTOM switch to ON
> ...


hi, i answer with best knowledge from my practise longtime ago. 
1. MONO switch to OFF- i set to OFF, but it may donot matter if you only use one channel for measurement.
2. PHANTOM switch to ON-set ON with MIC requiring Phantom power connected to either MIC in(L/R).
3. MIC/LINE or GUITAR switch to MIC/LINE-right setting
4. MON MIX knob to either all the way to the left (INPUT) or right (COMPUTER), I ll have to figure this out (will I hear distortion or something or will it just not give a signal you think?)- for your measurement need, please do not turn this knob to somewhere in middle(there will be some mix between source from input and source from computer, example, when measuring with sweeps playing in computer, always turn this knob to right END(computer). 
5. set INPUT RIGHT knob to a point where the SIG/OL led becomes red and then turn it down like 10% or so. After this do: -in REW i always use check level combine with AV reciver volume adjustment to reach desired sound presssure at SPL location, and with input right/left knob to adjust the input level to desired level ( my setting is -18dBFS. of course shall pay attention to the initial wav volume and output volume setting(there are suggestions in REW when you are at this step.
6. set the PHONES/LINE OUT knob to ?? (you will have to explain to me what the signal is that REW needs so on what value I will have to put the knob on).- see my comments in No.5. normally i don't use Phone, i use Lineout. you can put at somewhere in middle, and when setting right SPL reading(75DB), you can use volume
control at AV control center. after that, you adjust input level to -18DBFS by turning the input knob. 

don't know if i explained valuable info to you, and sorry, due to i am quite busy , no time to perform the testing from start to end again. hope i make some area clear to you.


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## jianhua1975 (Sep 13, 2011)

THX-UltraII said:


> I m going to use the Tascam 122 MKII with REW (+cross spectrum ECM8000). Can someone tell me step-by-step what I need to do for the Tascam to get it working correct with REW. The hardware (cabling) setup is already done: ECM8000 is connected to xlr R input of the Tascam and rca R output of the Tascam goes to my aux R+L input of my receiver (Marantz SR5005). What I need to know is what I have to do with:
> 
> - the mon mix (input/computer) knob
> - the phones/line out knob
> ...


yes, i suggest you calibrate the sound card first.


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## THX-UltraII (Nov 19, 2008)

Wayne A. Pflughaupt said:


> What Earl said.  But if for some reason you really need an external pink noise source, click the link in my signature and you’ll find an article on gain structure. In it you can find a pink noise signal you can download.
> 
> Regards,
> Wayne


and do I use 'PINK PN'?


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## THX-UltraII (Nov 19, 2008)

jianhua1975 said:


> yes, i suggest you calibrate the sound card first.


I ve heard that a calibration of the Tascam 122 MKII is not needed.


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## THX-UltraII (Nov 19, 2008)

jianhua1975 said:


> hi, i answer with best knowledge from my practise longtime ago.
> 1. MONO switch to OFF- i set to OFF, but it may donot matter if you only use one channel for measurement.
> 2. PHANTOM switch to ON-set ON with MIC requiring Phantom power connected to either MIC in(L/R).
> 3. MIC/LINE or GUITAR switch to MIC/LINE-right setting
> ...


Alright, so what I do is:
1. go to the preferences of REW and click on the 'check levels'.
2. choose check levels with main speakers (why can I also choose subwoofer?)
3. Adjust the INPUT RIGHT knob to a point where the SIG/OL led becomes red and turn the knob 10% down.
4. Adjust my receiver volume so my anlogue dB-meter shows 75dB
5. Set the LINE OUT knob half way.

correct?


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## THX-UltraII (Nov 19, 2008)

anyone?


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## Wayne A. Pflughaupt (Apr 13, 2006)

THX-UltraII said:


> Wayne A. Pflughaupt said:
> 
> 
> > What Earl said.  But if for some reason you really need an external pink noise source, click the link in my signature and you’ll find an article on gain structure. In it you can find a pink noise signal you can download.
> ...


Not sure I get the question? There is only one pink noise file linked in the article. There are no options for different types of pink noise. :scratch:

Regards, 
Wayne


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## Wayne A. Pflughaupt (Apr 13, 2006)

THX-UltraII said:


> I ve heard that a calibration of the Tascam 122 MKII is not needed.


No, the TASCAM has virtually ruler-flat response – doesn’t need a calibration file. However, that’s only for calibrating the line input /output. I don’t think anyone has performed the calibration with the mic pre-amp in the loop. If you want to give it a whirl, you can find more info on calibrating with the mic pre-amp here and here.

Regards, 
Wayne


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## THX-UltraII (Nov 19, 2008)

Wayne A. Pflughaupt said:


> Not sure I get the question? There is only one pink noise file linked in the article. There are no options for different types of pink noise. :scratch:
> 
> Regards,
> Wayne


What I mean is that the build-in signal generator in REW has 2 variations of pink noise (and some other types of test signals). I need to know which one I will have to use.


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## THX-UltraII (Nov 19, 2008)

Wayne A. Pflughaupt said:


> No, the TASCAM has virtually ruler-flat response – doesn’t need a calibration file. However, that’s only for calibrating the line input /output. I don’t think anyone has performed the calibration with the mic pre-amp in the loop. If you want to give it a whirl, you can find more info on calibrating with the mic pre-amp here and here.
> 
> Regards,
> Wayne


Ok, so I ll calibrate my Tascam soundcard first. Can you tell me which cable I need that fits the LINE IN and PHONES on the Tascam 122 MKII? (I need to loop/connect these two if I am correct)


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## THX-UltraII (Nov 19, 2008)

THX-UltraII said:


> Alright, so what I do is:
> 1. go to the preferences of REW and click on the 'check levels'.
> 2. choose check levels with main speakers (why can I also choose subwoofer?)
> 3. Adjust the INPUT RIGHT knob to a point where the SIG/OL led becomes red and turn the knob 10% down.
> ...


I m also looking for a reply on the above


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## Wayne A. Pflughaupt (Apr 13, 2006)

THX-UltraII said:


> Ok, so I ll calibrate my Tascam soundcard first. Can you tell me which cable I need that fits the LINE IN and PHONES on the Tascam 122 MKII? (I need to loop/connect these two if I am correct)


As noted, there is no reason to do a calibration for the US122 _unless you want to include the mic pre-amp_ in the signal chain. Even if you did, you loop the line input and line output, not the headphone output.

Regards,
Wayne


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## THX-UltraII (Nov 19, 2008)

Wayne A. Pflughaupt said:


> As noted, there is no reason to do a calibration for the US122 _unless you want to include the mic pre-amp_ in the signal chain. Even if you did, you loop the line input and line output, not the headphone output.
> 
> Regards,
> Wayne


but i AM using the mic pre-amp (phantom) ain t I?


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## Wayne A. Pflughaupt (Apr 13, 2006)

If you do a calibration looping the line in (1/4" jack) and line out, the mic pre-amp is bypassed. If you want to include the mic pre-amp in the signal loop, you'd have to use the TASCAM's XLR input. Probably best to switch off phantom power if you do that.

Speaking of, phantom power is an entirely separate entity. It is merely a means to provide power (piggy-backed on the audio signal wires, IIR) to a mic that that would otherwise require replacable batteries built into it. There is such a thing as a mic pre-amp that doesn't have phantom power.

Regards,
Wayne


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## Wayne A. Pflughaupt (Apr 13, 2006)

THX-UltraII said:


> What I mean is that the build-in signal generator in REW has 2 variations of pink noise (and some other types of test signals). I need to know which one I will have to use.


 Huh? I thought you were looking for a pink noise file you could download. It’s getting difficult to figure out where you’re going with this, so perhaps we should just back the boat up:




THX-UltraII said:


> Can I download a pink noise somewhere?


Why?

Regards,
Wayne


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## THX-UltraII (Nov 19, 2008)

I just still do not understand how to adjust the tascam in order to work properly when doing measurements. I know I have to adjust the right input knob to a point where the ol led becomes visible and then turn it back 10% but the 'problem' is that there is also the Line Out knob which has affect on the ol led. What I mean with this is that I can set the Line Out on eg 30% and the r input on 80% which results in 'ol led minus 10%' but I also get 'ol led minus 10%' when setting it the other way around: line out on 80% and r input on 30%.

you understand what I mean? :flex:


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## Wayne A. Pflughaupt (Apr 13, 2006)

My goof, I though the OL was only for the input signal. Just play with both knobs so that you don't get the OL light, but enough level for REW's input signal.

Regards,
Wayne


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## jianhua1975 (Sep 13, 2011)

THX-UltraII said:


> Alright, so what I do is:
> 1. go to the preferences of REW and click on the 'check levels'.
> 2. choose check levels with main speakers (why can I also choose subwoofer?)
> 3. Adjust the INPUT RIGHT knob to a point where the SIG/OL led becomes red and turn the knob 10% down.
> ...


it's actually simple procedure when you start to have hands on, no harm to just playing according to quite good instructions shown in Help section at each step. i try to make it simple to you to start. 

1. load existing cal file for both Mic and Soundcard, for Soundcard you can make one through calibration in preferences "soundcard" tab. just loopback lineout to input(must be right to right, left to left). 
then select either sub/main cal signal, set Sweep level at right level(default is -12dbFS), then turn line in level knob to be close to output level(within 3dB), if this is OK, then you can start to click "calibrate" to start the measure. after this procedure finished(you may need to observe headroom during this cal-measuring, no warning red:T). finally we can get a cal file which from "make cal", in following measurements, you just make sure the cal file is loaded. 

2. start measurements for your purpose, mains or/and subs. here i just propose you always make it simpler as possible, example, one main+SUB is quite good combination for starting. always try to play a full range sweep for measuring. 
loop back from output to input is not needed anymore, output connected to the AV receiver's Right/left input. i set Av receiver to stereo mode. activate the cross freq at what you want(my setting is 80Hz). 
Redo the check level for both sub and main(here i emphasize that you only use volume control at AV receiver&lineout knob at soundcard to reach 75DB reading on SPL ONCE for one speaker , then freeze the volume control at av receiver and lineout-knob at soundcard for following successing checking level on rest speakers/sub, instead you shall use level setting inside av receiver to reach 75dB reading on SPL, this is to maintain consistant sound pressure generated from each every speaker/sub). 

when 75DB reading achieved, you then turn the input knob on soundcard to reach input level between -24db~-12db(no higher then -12db). ideally shall be -18dBFS. 

when all above finished, you are good to go ahead with specific measuring, go to "measure" (top left). set right
sweep setting, then click "start measuring". (check level in measure is not needed anymore if you do as i said above).

you will get your first measurement!


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## THX-UltraII (Nov 19, 2008)

> for Soundcard you can make one through calibration in preferences "soundcard" tab. just loopback lineout to input(must be right to right, left to left).


Can I use this plug http://www.bax-shop.nl/jack-rca/procab-vc104-rca-female-jack-male-adapter/product-details.html and a single RCA cable for that?



> then select either sub/main cal signal


Does it not matter which one to use?



> set Sweep level at right level(default is -12dbFS), then turn line in level knob to be close to output level(within 3dB)


But what about the LINE OUT knob when doing this? Just put it half way? And do I have to use my dB meter too to achieve 75-80dB with adjustment of volume of AV receiver?



> Redo the check level for both sub and main(here i emphasize that you only use volume control at AV receiver&lineout knob at soundcard to reach 75DB reading


But this is a thing I don t understand: I can set my line-out knob eg. on 20% and push the volume of my AV receiver so I reach 75dB. But I can also reach the same 75dB my setting the line-out knob on eg. 80% and lower the volume of my AV receiver right? But which one 'is the right setting'?



> on SPL ONCE for one speaker. Then freeze the volume control at av receiver and lineout-knob at soundcard for following successing checking level on rest speakers/sub, instead you shall use level setting inside av receiver to reach 75dB reading on SPL this is to maintain consistant sound pressure generated from each every speaker/sub).


I understand what you mean here. This also has the benefit that I adjust the volume so all speakers has the right volume correct? One question though, I m looking for 75dB for each speaker right; how do I point my analogue dB meter? 45 degrees at ear/listening height for all 5 (R,L,C,SR and SL) speakers and keep pointing the dB meter in the same direction for all speakers? And what about setting on dB meter? A and slow? and A and slow also for subwoofer?




> when 75DB reading achieved, you then turn the input knob on soundcard to reach input level between -24db~-12db(no higher then -12db). ideally shall be -18dBFS.


So all the time in steps I did before I turn the input knob all the way down untill this step?


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## jianhua1975 (Sep 13, 2011)

THX-UltraII said:


> Can I use this plug http://www.bax-shop.nl/jack-rca/procab-vc104-rca-female-jack-male-adapter/product-details.html and a single RCA cable for that?


[jianhua]: it depends on your tascam 122 input/output type. you can make easy check just look at it. 



THX-UltraII said:


> Does it not matter which one to use?


[jianhua]: for loopback soundcard calibration, i think so. i don't really remember this. but just try both to see if any difference. 



THX-UltraII said:


> But what about the LINE OUT knob when doing this? Just put it half way? And do I have to use my dB meter too to achieve 75-80dB with adjustment of volume of AV receiver?


[jianhua]: in soundcard calibration, just put it somewhere, there will be realtime-indication show the level of both input and output,keep in mind that output arround -12dB FS,by turning output knob, then turn input knob to reach close to level of output. in this calibration work, you don't need any SPL reading. it's loopback calibration.
for real measuring, you use SPL reading to confirm 75DB sound pressure. then for first speaker, you combine lineout and AV volume control to reach that. after reaching this, you turn line in knob to reach input level arround -18dB FS.



THX-UltraII said:


> But this is a thing I don t understand: I can set my line-out knob eg. on 20% and push the volume of my AV receiver so I reach 75dB. But I can also reach the same 75dB my setting the line-out knob on eg. 80% and lower the volume of my AV receiver right? But which one 'is the right setting'?


[jianhua]: my understanding based on my pracising, it doesn't matter what combination you use to reach 75DB reading, the important thing is you freeze that down through the rest of speaker/sub measuring, and do not touch lineout knob or av volume control any more, instead you use level adjustment inside AV receiver to reach same 75DB reading on SPL. 



THX-UltraII said:


> I understand what you mean here. This also has the benefit that I adjust the volume so all speakers has the right volume correct? One question though, I m looking for 75dB for each speaker right; how do I point my analogue dB meter? 45 degrees at ear/listening height for all 5 (R,L,C,SR and SL) speakers and keep pointing the dB meter in the same direction for all speakers? And what about setting on dB meter? A and slow? and A and slow also for subwoofer?



[jianhua]: i set my radioshack SPL on at ear height with pointing at ceiling for all sub/speaker measurement. 
and my mic is also set like this. SPL set C and slow. 



THX-UltraII said:


> So all the time in steps I did before I turn the input knob all the way down untill this step?


[jianhua]: doesn't matter the inital position of input knob, important is that when you fix the output level, you shall adjust the input knob to reach -18DB according to the realtime-indicator of level for input and output


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## THX-UltraII (Nov 19, 2008)

> for loopback soundcard calibration, i think so. i don't really remember this. but just try both to see if any difference.


What difference will I see?



> in soundcard calibration, just put it somewhere, there will be realtime-indication show the level of both input and output,keep in mind that output arround -12dB FS,by turning output knob, then turn input knob to reach close to level of output. in this calibration work, you don't need any SPL reading. it's loopback calibration.
> for real measuring, you use SPL reading to confirm 75DB sound pressure. then for first speaker, you combine lineout and AV volume control to reach that. after reaching this, you turn line in knob to reach input level arround -18dB FS.


UNDERSTOOD! (I think  will test tonight)



> my understanding based on my pracising, it doesn't matter what combination you use to reach 75DB reading, the important thing is you freeze that down through the rest of speaker/sub measuring, and do not touch lineout knob or av volume control any more, instead you use level adjustment inside AV receiver to reach same 75DB reading on SPL.


OK



> i set my radioshack SPL on at ear height with pointing at ceiling for all sub/speaker measurement.
> and my mic is also set like this. SPL set C and slow.


Wayne told me to use 0 degrees (horizontal placement) measurement.



> doesn't matter the inital position of input knob, important is that when you fix the output level, you shall adjust the input knob to reach -18DB according to the realtime-indicator of level for input and output


OK!


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## jianhua1975 (Sep 13, 2011)

GOOD Luck with the measuring! 
when you put hands on, you will understand more i believe. 
i 've been strugling for long time before i made first measurement. read a lot of material just to be able
to start the first step. after, you will quickly feel better!


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## THX-UltraII (Nov 19, 2008)

Allright, did some more testing last night and even took my first measurement. But first some other things:

- I did a calibration of the soundcard and this went well.

- Then the level checking. This still raises some questions. First thing I did was putting the RIGHT INPUT knob all the way down. After this I put my receiver on -12 and the LINE OUT knob of the Tascam half way. My analoge dBmeter showed 75dB I think*. Here s a screenshot of what it looked like at that point:

After this I raised the RIGHT INPUT knob to a point where the input showed -18dB FS, so like this:

I think it might be important to note that I was ONLY able to reach this -18.4dB FS by turing the RIGHT INPUT knob ALL THE WAY to the maximum! (the sig OL LED is still green in this situation).

*I think my analoge dB-meter showed 75dB: I m not sure how to read my meter exactly because when I set my meter on the 70 range the meter shows +5 so I assume this is 75dB? Only strange this is that when I set it on the 80 range it shows -2 so this would assume that I is 78dB. My turning my AVR from -12 to -9 the dB meter says +5 and a bit in the 70 range and +0 in the 80 range so what is this then?? 75 and a bit or 80dB??

Ok after this I run a first measurement with:
- receiver on -12
- Tascam LINE OUT knob half way and RIGHT INPUT knob all the way to the right (max)
- dB meter on +5 in the 70 range (so I think 75dB??)
- AVR in stereo mode with subwoofer and main speaker active
- right output of Tascam to aux input left+right of AVR
- ECM8000 cross spectrum cal. with narrow_band_response_0_degree.frd file loaded and placed horizontal at listening/ear position
(- analoge dB meter also placed horizontal by the way)

I put the measurement values like this:


and also did a check levels again that showed '-18.2dB LEVEL OK'.

So after this I did a measurement and here I got a fault:


What does all this tell me, where do I make mistakes and where is it ok?

Thanks guys


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## Wayne A. Pflughaupt (Apr 13, 2006)

Would have been better to crop the screenshots just to show the REW information boxes; as it is they’re so tiny we can’t read your settings or the messages.

That said, with the “0.0 dB Headroom” flag it looks like your signal level (coming out of your speakers) is too loud. Reduce the AVR’s volume a bit and you’ll be good to go.

Yes, I know you – you followed the directions and set the level for 75 dB. IIR, the situation is that REW’s test signal for the SPL Calibration routine is only a _specific frequency range,_ not broadband. So when you go to make the actual measurement, it now includes frequencies that were not present in the Calibration signal, and some of those frequencies might be peaking above 75 dB. So that’s how you can get a clipping indicator even if you did the SPL Calibration to “spec.”

Regards, 
Wayne


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## THX-UltraII (Nov 19, 2008)

What is recommended for max value of headroom Wayne? If I want it to be GREEN (6.5) I need to lower my AVR volume a lot. Or is 3.0 or so (still red but not the fault anymore) good?


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## Wayne A. Pflughaupt (Apr 13, 2006)

If by “green” and “red” you’re talking about the signal LED on the Tascam, that has nothing to do with it. That has to do with the input levels for REW. We’re talking about the output from your speakers, which is controlled by the AVR’s volume control. Just turn down the AVR until it no longer gives you a “0.0 dB Headroom” indicator. Anything below that is fine.

Regards, 
Wayne


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## THX-UltraII (Nov 19, 2008)

Wayne A. Pflughaupt said:


> If by “green” and “red” you’re talking about the signal LED on the Tascam, that has nothing to do with it. That has to do with the input levels for REW. We’re talking about the output from your speakers, which is controlled by the AVR’s volume control. Just turn down the AVR until it no longer gives you a “0.0 dB Headroom” indicator. Anything below that is fine.
> 
> Regards,
> Wayne


With RED and GREEN i mean the numbers shown in REW when doing 'check levels' in 'make measurement'. 0.0 to 6.5 makes these numbers RED and from 6.5 and more they are GREEN so I assumed that I have to LOWER the volume of my AVR to a point where the HEADROOM is 6.5 or better.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Wayne A. Pflughaupt said:


> Just turn down the AVR until it no longer gives you a “0.0 dB Headroom” indicator. Anything below that is fine.
> 
> Regards,
> Wayne


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## chinni123 (Jan 8, 2012)

jianhua1975 said:


> Redo the check level for both sub and main(here i emphasize that you only use volume control at AV receiver&lineout knob at soundcard to reach 75DB reading on SPL ONCE for one speaker , then freeze the volume control at av receiver and lineout-knob at soundcard for following successing checking level on rest speakers/sub, instead you shall use level setting inside av receiver to reach 75dB reading on SPL, this is to maintain consistant sound pressure generated from each every speaker/sub).
> 
> Read more: Tascam 122 MKII setup - Page 3 - Home Theater Forum and Systems - HomeTheaterShack.com


What is meant by level setting inside av receiver? I am able to adjust volume knob on a/v receiver and line output to get 75db for speaker. However, when I disconnect speaker and connect subwoofer, I got complaint that either input is too low or no head room. If I freeze volume knob/line out knob, how do I fix head room or input too low?


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## Wayne A. Pflughaupt (Apr 13, 2006)

chinni123 said:


> However, when I disconnect speaker and connect subwoofer, I got complaint that either input is too low or no head room.


If the subwoofer is what you intend to measure, then do the SPL calibration using the subwoofer, not the main-channel speakers. :T

Regards, 
Wayne


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## chinni123 (Jan 8, 2012)

Wayne A. Pflughaupt said:


> If the subwoofer is what you intend to measure, then do the SPL calibration using the subwoofer, not the main-channel speakers. :T
> 
> Regards,
> Wayne


Thanks. The question I have is if you need to test in the following scenarios and compare at same levels, how is it possible to freeze volume of a/v and line out knob at 75db and test them without needing to change them to face problems with head room or not enough/too much input signal.

Just Left
Just sub
Left+sub


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## Wayne A. Pflughaupt (Apr 13, 2006)

Not sure I get the question, but if you’ve done the SPL Calibration Routine for 75 dB and then, when you go to measure, you get a low- or high-signal indicator, then you obviously have to adjust the receivers volume control to compensate. It’s not unusual to get a low- or high-signal warning when you go to measure, because the measurement signal is broadband, while the calibration signal is not.

Regards, 
Wayne


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## chinni123 (Jan 8, 2012)

Wayne A. Pflughaupt said:


> Not sure I get the question, but if you’ve done the SPL Calibration Routine for 75 dB and then, when you go to measure, you get a low- or high-signal indicator, then you obviously have to adjust the receivers volume control to compensate. It’s not unusual to get a low- or high-signal warning when you go to measure, because the measurement signal is broadband, while the calibration signal is not.
> 
> Regards,
> Wayne


Thanks Wayne. Good to know the difference. Every check of combination of measurement (left or left with sub etc), I check levels. After testing left speaker, if next testing for subwoofer needs changes (to satisfy head room etc), does it not affect what I read that *Line out/Receiver volume should freeze throughout measurements of different combinations?*. 

I calibrate speaker one time. I know that as long as input level knob is not changed speaker does not calibration again. Still for other measurements, I get that input is too low/high. Then, I need to change and calibrate speaker again. It is pain. I am missing some trick.

My question is to really test different combinations, as long as check levels adjusted to 75db, all the measurements are comparable. For example I tested speaker at 75db. Some how, until I increased to 90db with subwoofer, I got head room/input level problem. I am worried if I am not doing right.


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## Wayne A. Pflughaupt (Apr 13, 2006)

It’s perfectly normal to have to re-do the SPL Calibration routine any time you measure a different speaker, subwoofer, etc. And after you equalize a sub, too. That’s probably going to require you to re-adjust the receiver’s volume control. It’s not a problem, and it has no bearing on the accuracy of any measurements. If you _don’t_ re-adjust the receiver’s volume as needed, you might get a low- or high-signal flag (as you know), and _that’s_ a problem. :T

Regards,
Wayne A. Pflughaupt


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## chinni123 (Jan 8, 2012)

Wayne A. Pflughaupt said:


> It’s perfectly normal to have to re-do the SPL Calibration routine any time you measure a different speaker, subwoofer, etc. And after you equalize a sub, too. That’s probably going to require you to re-adjust the receiver’s volume control. It’s not a problem, and it has no bearing on the accuracy of any measurements. If you _don’t_ re-adjust the receiver’s volume as needed, you might get a low- or high-signal flag (as you know), and _that’s_ a problem. :T
> 
> Regards,
> Wayne A. Pflughaupt


Thanks Wayne. I will try to make sure I get every time 75db and input level is around -18db and calibrate spl meter whenever input knob is changed. I thought changing any of the knobs, will mess up measurements not comparable with one other and combinations (for example Left (alone) + sub (alone) != sub+left when knobs changed ).


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## jianhua1975 (Sep 13, 2011)

chinni123 said:


> What is meant by level setting inside av receiver? I am able to adjust volume knob on a/v receiver and line output to get 75db for speaker. However, when I disconnect speaker and connect subwoofer, I got complaint that either input is too low or no head room. If I freeze volume knob/line out knob, how do I fix head room or input too low?


volume knob will adjust volume for all channels. so when you connect to one channel and through volume knob to reach 75 DB, the unconnected channels volume also been changed, same when you connect to another channel. that means you will never reach all channel identical at 75DB.

so you need to adjust seperately each channel's level, there must be such adjust option within your AVR. 

you only touch Lineout&AVR's volume knob for first channel level adjust, then freeze the volume knob&lineout
level for rest channel level adjustment. only adjust the related channel's level inside AVR to reach 75 DB.


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## chinni123 (Jan 8, 2012)

jianhua1975 said:


> volume knob will adjust volume for all channels. so when you connect to one channel and through volume knob to reach 75 DB, the unconnected channels volume also been changed, same when you connect to another channel. that means you will never reach all channel identical at 75DB.
> 
> so you need to adjust seperately each channel's level, there must be such adjust option within your AVR.
> 
> ...


Thanks. That makes sense. I never thought about what is really increasing volume implies for all channels. In my AVR, I have level calibration to increase +1db, +2db etc for each channel (left, right, surround left, surround right, sub). Do you mean to adjust this?

The freeze of av volume and line output should apply to even subwoofer?

This is my understanding.

1. Connect only left speaker and check levels to make 75 db and freeze volume and line out knobs.
2. Complete measuring Left alone
3. Disconnect Left and connect only right
4. Go to level calibration and increase/decrease it to get 75db while doing check levels.
5. Measure right.

So on continue. Is it right?

The complications comes when combination like subwoofer+left connected etc to reduce/increase knob on subwoofer or increase/decrease levels of subwoofer or left etc.

I am also assuming that as long as it is 75db, I don't get complaint that there is no head room so that I don't need to change line input knob and do speaker calibration.

What is real intent of freezing the volume at 75b? Is increasing/decreasing level calibration does not affect?


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## jianhua1975 (Sep 13, 2011)

chinni123 said:


> Thanks. That makes sense. I never thought about what is really increasing volume implies for all channels. In my AVR, I have level calibration to increase +1db, +2db etc for each channel (left, right, surround left, surround right, sub). Do you mean to adjust this?
> 
> The freeze of av volume and line output should apply to even subwoofer?
> 
> ...


you may misunderstand me, to adjust each channel to reach 75dB, the main purpose is to have identical sound pressure from each speaker at LP. take an extreme example, if L-C-R-LS-RS speakers are with different
impedence, 4ohm or 8ohm, if you don't do this adjustment for each channel, the sound pressure shall be different from each channel at LP. so this sound pressure adjustment to 75dB for each channel is a must for your system, it's not relating to the specific measurement you will do afterwards. 

for single measurement afterwards(you already completed the sound pressure adjustment for each channel to be identically at 75db), you can freely adjust the volume knob or line-out to get whatever suitable sound pressure you want as long as you never touch the level adjustment inside AVR for each channel any more!.

hope you can understand now.


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## chinni123 (Jan 8, 2012)

jianhua1975 said:


> for single measurement afterwards(you already completed the sound pressure adjustment for each channel to be identically at 75db), *you can freely adjust the volume knob or line-out to get whatever suitable sound *pressure you want as long as you never touch the level adjustment inside AVR for each channel any more!.
> 
> hope you can understand now.


Post 2


jianhua1975 said:


> you only touch Lineout&AVR's volume knob for first channel level adjust, *then freeze the volume knob&lineout*
> level for rest channel level adjustment. only adjust the related channel's level inside AVR to reach 75 DB


Thanks for the reply. I understood better, but not clear. What you are saying is first do level calibration. I never did it manually before because Anthem correction software runs these tests and sets levels automatically. I will do manually. I guess I run it for each channel and increase/decrease levels (like +1, +2 etc) after verifying on RS meter to get to 75db. 

You said freeze volume/line out in one post and in another free to change them. Do you mean freeze for each channel and change for next channel? I only do only one measurement for each channel from 20 to 20khz. May be you are applying to freeze for multiple measurements for same channel and then feel free to change for next channel to get to 75db? I imply channel means left speaker or right speaker.


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## jianhua1975 (Sep 13, 2011)

chinni123 said:


> Post 2
> 
> Thanks for the reply. I understood better, but not clear. What you are saying is first do level calibration. I never did it manually before because Anthem correction software runs these tests and sets levels automatically. I will do manually. I guess I run it for each channel and increase/decrease levels (like +1, +2 etc) after verifying on RS meter to get to 75db.
> 
> You said freeze volume/line out in one post and in another free to change them. Do you mean freeze for each channel and change for next channel? I only do only one measurement for each channel from 20 to 20khz. May be you are applying to freeze for multiple measurements for same channel and then feel free to change for next channel to get to 75db? I imply channel means left speaker or right speaker.


if Anthem already done this for you then it's good enough. 
line-out/volume knob are fixed adjustment for each channel, you will From time to time to turn the volume knob each time you listen music for watch movie, right? and line-out is only adjusting output signal level from soundcard. so they are not fixed adjustment. but they can be used to help for set up a reference sound pressure (75dB)for first channel, then you need to fix the volume/line-out, and adjust other channels only using level setting inside AVR to compensate related channel output sound pressure(example caused by different output impedence of different type speakers).

once you done that, level setting for each channel then shall be freezed. 

then you start to make measurement for other purposes, as long as you don't touch the internal level setting
of each channel. you can turn the volume/line-out whatever you want, and since you already get all channel identically consistant. so you change volume/line-out to get one sound pressure at one channel, when you connect the same signal to other channel, you expect to have a same sound pressure too.


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## chinni123 (Jan 8, 2012)

jianhua1975 said:


> if Anthem already done this for you then it's good enough.
> line-out/volume knob are fixed adjustment for each channel, you will From time to time to turn the volume knob each time you listen music for watch movie, right? and line-out is only adjusting output signal level from soundcard. so they are not fixed adjustment. but they can be used to help for set up a reference sound pressure (75dB)for first channel, then you need to fix the volume/line-out, and adjust other channels only using level setting inside AVR to compensate related channel output sound pressure(example caused by different output impedence of different type speakers).
> 
> once you done that, level setting for each channel then shall be freezed.
> ...


Thanks for clarifying. It is true that it should be same signal. Some how, subwoofer or subwoofer combination with Left speaker needed change in volume.

Since I messed up settings, I will re run Anthem correction which will do level calibration and run REW again. I need to make sure the level knob on Subwoofer is set in such a way that level calibration for subwoofer will only show only + or - 3db. Previously, it was at -10db. It may be the problem for need to change volume or level out.

Thanks again for all your replies.


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