# New kid on the block...



## mogorf (May 27, 2009)

Hi Guys,

This is my first post on this thread, so please allow me to introduce myself, briefly. At 53 I have an electric engineer's background, though my major was wireless telecommunications. Nonetheless, I've always been a hi-fi enthusiast throughout the years behind me, love music and love all technical background that makes audio sound better and better. Just recently took the plunge and bought a Denon 2310 with Dali speakers + sub (Concept series) and set up my 7.1 system (6 and 7 are front heights) with Audyssey doin' its magic in my room.

Now I'm into REW, I'd like to visualize what my system +room is doing, my learning curve already started, know what hardware I will need to buy, actually already bought a Behringer UCA-222 external sound card with line in/ line out for my laptop. Most probably it would be a good decision to buy a Behringer ECM-8000 mic, but before that I'd like to ask the Board here as follows:

I have a vintage type mic Akai ACM-50. It's an electret condenser mic (uni-directional).

1. Do you think this mic would be suitable to do measurement?

2. We all know that "difficulties of development" are always and immediately followed by "development of difficulties", (just kidding!:help, so do you think I could find a calibration file for this mic somewhere on the Net?

Your kind assistance will be highly appreciated.


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

Welcome to the Forum, Feri!



> ...so do you think I could find a calibration file for this mic somewhere on the Net?


 Doubtful, the company that was Akai back in the vintage days is defunct, and the mic was probably sourced from an outside vendor. But hey, you never know what Google might turn up. :T

Regards,
Wayne


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## mogorf (May 27, 2009)

Wayne A. Pflughaupt said:


> Welcome to the Forum, Feri!
> 
> Doubtful, the company that was Akai back in the vintage days is defunct, and the mic was probably sourced from an outside vendor. But hey, you never know what Google might turn up. :T
> 
> ...


Thanks Wayne for your kind welcome. I'll see what Google might bring up. :dontknow:


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## mogorf (May 27, 2009)

mogorf said:


> Thanks Wayne for your kind welcome. I'll see what Google might bring up. :dontknow:


Nothing for the Akai mic on the Net, so I'll take the ECM-8000 mic route.

Another Q, if I may.

To measure the perforamce of each of my speakers + sub in the room individually and independently from all the other speakers, can I use the Ext. In RCA sockets on the Denon to feed the analog test signals of REW? 

Like this: Sound card right output -> Denon Ext. In (for the respective speaker channel), and go through with the measurements on all inputs one by one till I get 8 graphs.

Thanks in advance.


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

Can't think of a reason why that wouldn't work. :T

Regards,
Wayne


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## mogorf (May 27, 2009)

Wayne A. Pflughaupt said:


> Can't think of a reason why that wouldn't work. :T
> 
> Regards,
> Wayne


Thanks Wayne, that's great news. If my understanding is correct, this means I can test my 5.1 (actually 7.1) system with REW and see the performace of each and every channel independently (Denon/Audyssey + speakers + room effect in total), right?


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## EarlK (Jan 1, 2010)

Hi Feri,



mogorf said:


> snip,,,,,Now I'm into REW, I'd like to visualize what my system +room is doing, my learning curve already started, know what hardware I will need to buy, actually already bought a Behringer UCA-222 external sound card with line in/ line out for my laptop. ,,,,,snip ,,,,,,


Since the UCA-222 soundcard only accepts line level input, if you choose to buy a measurement microphone with standard mic level output ( like the ECM 8000 ) , you'll also need to purchase a microphone preamp to boost its signal up to line level .


The REW FAQs pages make a couple of recommendations ( I can't really find them right now ), one being a small Behringer mixer with phantom ( 48 V ) power ( which is necessary for just about all measurement microphones ) . Here's a pic ;










It's wired as a test system like this ;










The cheaper alternative is to buy a Radio Shack mic ( used ? maybe ) since it will output a line level signal directly into your existing soundcard ( UCA-222 ) . Below 3000hz ( & when used with it's calibration file ) it provides good enough accuracy for most measurements .

It looks like this  

It's setup like this ;









Hope something here helps .


<> cheers


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

mogorf said:


> Thanks Wayne, that's great news. If my understanding is correct, this means I can test my 5.1 (actually 7.1) system with REW and see the performace of each and every channel independently (Denon/Audyssey + speakers + room effect in total), right?


Yes, except that I don’t know of Audyssey is intact or bypassed via the Ext. inputs. Check your manual.

Regards,
Wayne


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

Adding a bit to Earl’s excellent information, the Behringer XENYX 502 mixer now offers phantom power, and is even cheaper than the 802. :T

Regards,
Wayne


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## mogorf (May 27, 2009)

Wayne A. Pflughaupt said:


> Adding a bit to Earl’s excellent information, the Behringer XENYX 502 mixer now offers phantom power, and is even cheaper than the 802. :T
> 
> Regards,
> Wayne


Thanks Earl and Wayne for your valuable information, as always.

Checked my Denon and unfortunately I have to report that Audyssey is off when selecting Ext. In. A pity, coz I had the plan to do the A/B-ing with room correction on and off to see the difference not only for the frequency range of each speaker in my system, but also later on in the time domain (waterfall plots, etc.)

No clue for workaround on my side for the time being.:sad:

Cheers, Feri


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## laser188139 (Sep 19, 2009)

Which Denon, Feri? 

Why do you want to use the EXT.IN? On my AVR-989, the V.AUX inputs on the front panel are perfect, in that one can enable/disable Audyssey as one likes, and it makes it very easy to use one or the other of the front channels to measure them separately. 

For that matter, you could use the RCA analog inputs for any of the sources. Run an extension cable from the back to the front so you can plug in the cables from your computer. Then switch that source to analog instead of digital when you want to take measurements. 

It becomes a little more awkward when you want to go beyond measuring the front two speakers. The usual recommendation then is to re-cable, such that the speakers you want to test are connected to the receiver as the front and back. That's easy when you want to measure them with Audyssey Off, but awkward to re-run Audyssey with the speakers in a different configuration of front/side/back. 

Bill


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## mogorf (May 27, 2009)

laser188139 said:


> Which Denon, Feri?
> 
> Why do you want to use the EXT.IN? On my AVR-989, the V.AUX inputs on the front panel are perfect, in that one can enable/disable Audyssey as one likes, and it makes it very easy to use one or the other of the front channels to measure them separately.
> 
> ...


Hi Bill, its the Denon 2310. I'll try the V.AUX inputs on the front as you suggested, but my original idea was to see how it is possible to make multi-channel measurements of each speaker individually and respectively in my 7.1 setup. 

Running an extension cable from the back to the front in order to plug in the cables from the computer: I don't really get it. Can you expand on this one, please? Thanks a lot.

Cheers, Feri


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## laser188139 (Sep 19, 2009)

mogorf said:


> ... Running an extension cable from the back to the front in order to plug in the cables from the computer: I don't really get it. Can you expand on this one, please? ...


I was just thinking if you had some Denon model without V.AUX RCA connectors on the front, you could use connectors on the back instead. While I'm doing my testing, I have an extension cable connected to the front channel preouts so I can measure them to see what Audyssey does before reaching the speakers, without having to reach around to the back of the cabinet each time. 

Bill


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

You could just use the Receiver's front AUX input for the left and right main channels at least...

Regards,
Wayne


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## tpaxadpom (Jul 15, 2006)

Just connect it to 2 front aux inputs (left and right). Engage 5 channel stereo mode. Go to the receiver menu and turn one speaker at a time, if it doesn't allow to disable left and right fronts separately then do it manually. Same with the subwoofer.
Most receivers nowdays digitize all analog inputs, so that they can utilize their DSP processors to do bass management, room correction ... If yours doesn't do that then you can use different software to do your measurements. Google for RMAA (right mark audio analyzer). That software can generate wave file that you can burn to cd and later have it playedback on your dvd/cd player. Alternatively if your PC/soundcard has a digital out run it directly to your receiver, this way you can use REW (btw my favorite app).
I typically use REW in my 2 channel setup. No eq's are used with the exception of single band parametric EQ on my SVS PB-13Ultras. I've done some checking in my HT setup where I use Onkyo 805 as a preamp/processor and it does the job quite well. Though I did notice that it doesn't change the phase of the subwoofer. I manually readjusted it to get the smoothest FR in the sweet spot using REW. BTW I reran Audyssey calibration and noticed that nothing was changed, in other words Audyssey doesn't do anything when I change the phase on my sub.


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## mogorf (May 27, 2009)

tpaxadpom said:


> Just connect it to 2 front aux inputs (left and right). Engage 5 channel stereo mode. Go to the receiver menu and turn one speaker at a time, if it doesn't allow to disable left and right fronts separately then do it manually. Same with the subwoofer......


Thanks guys. Using v.aux with the combination of 5 ch stereo really sounds like a good option to test each speaker independently. At the moment I can not think of a way to turn off the speakers (except the sub which has a power button), so I'll need to take the hard way and disconnect the speaker cables.

Thanks again.


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## laser188139 (Sep 19, 2009)

tpaxadpom said:


> ... Engage 5 channel stereo mode. Go to the receiver menu and turn one speaker at a time, if it doesn't allow to disable left and right fronts separately then do it manually. Same with the subwoofer. ...


Andrey, that is a clever idea. As Feri remarked, one can always disconnect the other speakers to measure only one individually.


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