Do I need a ECM8000 ?

[jwhite8086]

I have a digital Radio Shack meter, and want to start doing measurments.
The meter has been droped a few times I guess its still acurate.
do I need the ECM for high frequency readings, or can the Galaxy do that too, or will my old Radio shack meter do everything ?

[brucek]

The Radio SHack meter is not suitable for full range measurements. I don't remember ever checking the accuracy of the Galaxy for high frequencies. Generally you should use a flat measurement microphone such as the ECM8000 for full range testing...

brucek

[Josuah]

Note that the ECM8000 is not really a flat measurement microphone. Being picky, but you can see the radial differences in measurement accuracy printed on the box itself. And don't forget you need to get a calibration file as well.

[clausdk]

Im going to replace my radioshack with this, but I was wondering, what connection type is the ECM 8000? minijack or rca?

It doesnt say so on the Behringer website actually.

[brucek]

what connection type is the ECM 8000? minijack or rca?

XLR. It's a balanced output to feed a balanced input preamp like the XENYX802

brucek

[clausdk]

Oh ok, so to connect this to my PC i need? XLR to minijack or that preamp as well?

[brucek]

Oh ok, so to connect this to my PC i need? XLR to minijack or that preamp as well?

Yeah, this an electret condenser type balanced mic that outputs a very low level (not line level).

It needs a microphone preamp that supplies a phantom voltage to power it, and a gain stage to bring it up to a line level.

The output of the preamp I linked above is also balanced, but can be used single ended on the output by using 1/4" TS phono plugs.

The ECM mic can either plug directly into the preamps XLR input jacks or a full XLR cable can be used if you want to mount the mic on a tripod.

The output cable from the preamp (as shown below) would be a 1/4" TS phono to RCA. The RCA would be adapted at the soundcard to feed the left or right channel of the stereo line-input.



brucek

[clausdk]

Ok I see, thanks.

The microphone and amp will cost me around 200$ in Denmark. Worth the upgrade over the normal Radioshack I use right now? I would only use this to EQ my sub.

[brucek]

Worth the upgrade over the normal Radioshack

Have you considered the Galaxy CM-140 SPL meter. It's a fairly high quality SPL meter (like the Radio Shack, except it's not a toy). We have the cal file for the Galaxy on our downlload page..

brucek

[clausdk]

Nope, but I would certainly do so! Can't find any seller in Denmark for one of these, but I see some debate on this site about it.

[Sonic Icons]

Hello,

I'm also thinking of getting the ECM8000 to allow full-range measurements. I was looking in Parts Express for the parts needed to use this microphone in REW. (I have done measurements in REW before with a Radio Shack digital SPL meter, so I only need new parts that are specifically associated with the ECM8000.) I came up with the following, and would appreciate it if someone could tell me whether these look OK

(1) To begin, the ECM8000 microphone (http://www.partsexpress.com/pe/showd...number=248-625)

(2) Rolls MP13 Mini-Mic Preamp with Phantom Power (http://www.partsexpress.com/pe/showd...number=245-032)
This appears to be the correct type of preamp for the ECM8000. Specs include XLR balanced and 1/4 inch unbalanced inputs and outputs, 36 V phantom power, gain adjustable from +6 dB to +50 dB.

(3) Dayton CMX-25K XLR Microphone Cable (25 ft.) (http://www.partsexpress.com/pe/showd...number=241-348)
Connect microphone to preamp; allow reasonably long distance from the microphone to "workstation" (where the laptop computer is set up).

(4) Microphone Floor Stand, adjustable height 33 to 61 inch (http://www.partsexpress.com/pe/showd...number=242-015)
Stable positioning of microphone at listening height.

(5) 3.5mm Stereo Male To Male Cable 3 ft.(http://www.partsexpress.com/pe/showd...number=240-095)
Connect preamp (unbalanced) output to soundcard line input. (Note the connectors on this cable are sometime called 1/8 inch phone plugs, but 3.5 mm is more correct.) (Note that one more part is needed from the Rolls MP13 preamp to this cable, a 1/4 inch to 3.5 mm phone plug adapter, but I already have that.)

[brucek]

Looks fine except for #5.

The soundcard input is stereo, but we want to 'break out' those two channels to separate left and right channels, so we can feed only one with the microphone signal.

So you need a 3.5mm adapter like the one shown below.

Then one of those mono (left or right) channels is fed from the mono output of the mic preamp by using a mono 1/4" TS connector at the mic preamp output.

.

brucek

[Sonic Icons]

Thanks for your speedy help, you deserve a bonus for working on the weekend

Also, for calibrating the frequency response of the preamp / soundcard combo, in the loop-back configuration, I think I will need a second of these Y cables, to connect the stereo, TRS "front speaker" output of the soundcard to the mono, TS input of the preamp.

By the way, I found the following Wikipedia articles helpful on common audio connectors:

TRS (Tip-Ring-Sleeve), and TS (Tip-Sleeve) connectors (often called phone plug connectors, common sizes are 1/4 inch and 3.5 mm)
http://en.wikipedia.org/wiki/Tip_ring_sleeve

XLR connector (found on professional audio equipment such as the Behringer ECM800 microphone and Behringer Feedback Destroyer):
http://en.wikipedia.org/wiki/XLR

(Now I need to read other posts to figure out what cables people use to connect the BFD to their systems)

[brucek]

Also, for calibrating the frequency response of the preamp / soundcard combo, in the loop-back configuration, I think I will need a second of these Y cables, to connect the stereo

Yeah, that's right. To include the preamp in the loopback cabling during the soundcard calibration, you would need the soundcards line-out and line-in split-out to use either its right or left channel. You would insert the preamp in that loop for the calibration using the preamps 1/4" line-in (with a mono TS plug) and the preamps 1/4" line-out (with a mono TS plug).

what cables people use to connect the BFD to their systems

Everyone uses something different because there are so many situations. The BFD allows for a lot of different balanced/unbalanced connections, so it's whatever works the best in your situation.

Some people have a problem with the RCA to 1/4" TS adapter and order RCA to 1/4" TS cables if their system is all unbalanced. That's probably the best way to go. If you have any balanced connections, I like the XLR connection better.

brucek

[Sonic Icons]

This y-adapter cable looks even better, because it allows connecting the mono, 1/4" TS output (or input) of the preamp to one channel of the stereo, 3.5 mm TRS line input (or output) of the soundcard, without any additional adapters:

http://www.ramelectronics.net/html/adapters-14-18.html
part # 35-476

and the same vendor has RCA to 1/4" TS adapter cables that look to be well-built (for inserting the Behringer feedback destroyer between components with RCA connectors):

http://www.ramelectronics.net/html/RCA-to-1-4.html
parts # GA5-3 to GA5-20

Instead of a mixer like that, why not get a Sound Card like this that has phantom power?

IT also acts as a sound Card.

http://www.emu.com/products/product....&product=15185

E-Mu 0404

[clausdk]

I think I'll go for the galaxy mic with associated cal file. I'm moving into my new house in 4 months, just spend several days planning out various cabling :=) Can't wait to set it all up and dail it all in

[jerome]

brucek wrote:

Have you considered the Galaxy CM-140 SPL meter. It's a fairly high quality SPL meter (like the Radio Shack, except it's not a toy). We have the cal file for the Galaxy on our downlload page..

What is the best option for us who want to upgrade from a Radio Shack and only want to use it for calibration: ECM8000 or Galaxy CM-140 SPL meter ?

From what I have read on this forum, it sounds like ECM8000+EMU0404/XENYX802 or CM-140 would be good alternatives for a calibration job. Besides the price difference, is there any significant quality difference on the two microphones ?

[brucek]

Besides the price difference, is there any significant quality difference on the two microphones ?

The ECM8000 with a preamp is a better full range microphone, offers balanced output, and provides control over the level, but you do require an SPL meter for use with REW. The Galaxy is quite good for sub calibration and is an all in one solution..

brucek

"The output of the preamp I linked above is also balanced, but can be used single ended on the output by using 1/4" TS phono plugs" :
I think it's dangerous to write that. The phantom power link is not described !.

JMRaudio, french new member
http://jmraudio.free.fr/profil/profil.html

[brucek]

I think it's dangerous to write that. The phantom power link is not described !.

There is no phantom link on the line outputs of this preamp. The phantom voltage is only available at the XLR microphone inputs. Behringer recommends using the 1/4" TS plugs for either input or output unbalanced lines.

brucek

[penngray]

The ECM8000 with a preamp is a better full range microphone, offers balanced output, and provides control over the level, but you do require an SPL meter for use with REW. The Galaxy is quite good for sub calibration and is an all in one solution..

Im confused as always...you seem to say that we need a SPL meter even if we own a mic like the ECM8000 ( I have the Nady cm-100)?? I thought these condenser measurement mics do it all for us with REW?

[brucek]

you seem to say that we need a SPL meter even if we own a mic like the ECM8000 ( I have the Nady cm-100)?? I thought these condenser measurement mics do it all for us with REW?

A condensor mic does do it all (along with an appropriate preamp), except there's one thing missing. How do you set a known SPL level at your listening position during REW setup, so you can tell REW what that level is. Otherwise REW isn't calibrated to any known level. This requires an SPL meter (hand held and used once during the REW setup and then put away). The condensor mic does all the measuring.

Actually, you can get away without an SPL meter, by simply guessing at the 75dB level and telling REW the level is 75dB. If it was actually 79dB, it simply wouldn't matter.... Most people have an old SPL meter around though.

brucek

[penngray]

thanks, I do have an RS SPL meter so I will ensure I have the 75db level.....

on to learn some more until I get my pre-amp...maybe my art clean box will work, it has rca and xlr out and it increases the signal.

[brucek]

maybe my art clean box will work, it has rca and xlr out and it increases the signal.

No, you need a mic preamp. These are extremely low levels and require special handling to get to the line level.

brucek