Cable between UB802 and ECM8000 mic, SpeakerWS question

[RavS]

I'm trying to finally acquire all the gear I need to do my own measurements.
Just had a few questions.

1)What kind of XLR cable do I need between UB802 and ECM8000? Is it just a standard low-z xlr microphone cable (xlr male to xlr female)? Or is it a xlr male to male cable? I tried looking for a pictures of the ecm8000 xlr socket, but I couldn't find any on the web.

2)I wanted to use speaker workshop for my measurements. Do I need to build a Wallin type jig to do measurements, or will the ECM and UB mixer suffice? I only need to do measurements, not test any driver parameters. I own a DCX that will be used for all XO duties.

Thanks in advance for your help!

[Saurav]

LOL... I'd been thinking about posting the exact same question. In fact, when I saw your thread, my first thought was "When did I post that? I don't remember posting that"

[Spearmint]

I'm trying to finally acquire all the gear I need to do my own measurements.
Just had a few questions.

1)What kind of XLR cable do I need between UB802 and ECM8000? Is it just a standard low-z xlr microphone cable (xlr male to xlr female)? Or is it a xlr male to male cable? I tried looking for a pictures of the ecm8000 xlr socket, but I couldn't find any on the web.


Thanks in advance for your help!

Can only assist with Q1, it is a standard Male/Female XLR lead, the mic has a male connector...

[JonMarsh]

You need the jig to do impedance measurements; but if you have published data, you can may be able to use the FRD Consortium tools to synthesize impedance curves if you can import that data to Speaker Workshop.

[cjd]

If you're doing just measurements, you still should go through the full SW setup process for the most accurate results. It's not hugely difficult, particularly if you actually build the Wallin jig instead of using cables such as those Claudio outlines in his tutorial (which, btw, is thorough and worth using). It's also nice because you can do *all* the measurements. I think VAS is the only miserable one to figure, since you either need to mass-load or you need a sealed box to play in. I find impedance worth measuring since it tells you more clearly than anything what your box tuning is. Easy easy to do. I wouldn't bother trying to skip this step. It also means you have an easy way to measure caps, resistors, and inductors accurately.

I'm using just the cables, not the Wallin jig (I have both cable sets). Same mic and mixer. I'm considering building the jig though.

Room can play interesting games with your results, particularly in how it relates to setting up proper gating (which, if NOT done well, can similarly play games with results).

As far as the FRD Consortium tools and existing measurements (such as those PE publishes) - if my MTM project means anything, it suggests you can get VERY good results this way. The trick is understanding how to use them all. You can also generate impedance curves, but it's easier to just measure.

C

[Saurav]

My biggest problem right now is that my laptop has a mono mic input, not a stereo line input. So I don't have a 'reference channel'. SW seems to be OK with that as far as acoustic measurements go, but I'm not sure if I can measure impedances that way.

Also, the output of the UB802 is at mic level, right, so I can send it straight to the mic input of my soundcard? Or is it line level or some other pro level that will need attenuation? How have you conected that to your computer? Cable(s)? Attenuation?

[cjd]

Do not use the mic in if you can help it. Noisy. You have no line in?! Far as I know it's line output levels, but I don't know what voltage that is, or how it compares to mic output.

No reference may be tricky - not sure. I do know that getting the levels right is more important than I initially thought. But, I also found the on-board sound of my desktop to be inadequate.

Pick up an M-Audio Transit - I'm 99% sure it has everything you could want as far as low noise floor and the appropriate connections. Oh yeah... more money. Never a good answer. Retail at $99.95 but supposedly available (if you can find it) for ~$79?

I have the cables Claudio outlines: on one end of the cables, a pair of stereo jacks with the right channel looped right from one to the other. On the other end, from the left channel output jack to an RCA plug that goes to the amp. And a 1/4" mono jack from the output of the UB802 to the left channel line input. Don't quote me on right and left, but I'm pretty sure I have 'em right here.

C

[Saurav]

Yeah, the transit is probably next on the list when more funds accumulate in my toys account.

I'm trying out new baffles today. Only stuff that can be cut with a jigsaw I just cut something that looks like a rt. angled triangle on top of a rectangle. Wife says it looks like a dunce cap.

[cjd]

tried the one I outlined for you yet? :P Mostly, I'm just curious.

Jigsaw is fine. Works great for what you're doing. Have you tried a hardboard piece to make the drivers "flushmount"?

Dunce cap sounds about right. All those alligator clips plus dunce cap may not bring good images to mind these days, however. :|

C

[RavS]

LOL... I'd been thinking about posting the exact same question. In fact, when I saw your thread, my first thought was "When did I post that? I don't remember posting that"

Kill two birds with one stone, what could be better than that

[RavS]

Can only assist with Q1, it is a standard Male/Female XLR lead, the mic has a male connector...

Just so I have this straight, the ECM8000 socket has 3 prongs, and therefore a male socket? But the XLR cable plug needs to be female to plug into the mic right?

Thanks for your help.

[RavS]

You need the jig to do impedance measurements; but if you have published data, you can may be able to use the FRD Consortium tools to synthesize impedance curves if you can import that data to Speaker Workshop.

Thanks Jon. Since this project is a openbaffle using digital XO, impedance measurements don't seem to be necessary at this point. But for future projects, I might have to take CJD's advice and build a jig. Makes me shudder just thinking about it :unsure:

[Spearmint]

Just so I have this straight, the ECM8000 socket has 3 prongs, and therefore a male socket? But the XLR cable plug needs to be female to plug into the mic right?

Thanks for your help.

Correct...

[cjd]

Uh... the "jig" you need, if you just do the cables, doesn't even require soldering or wiring in jacks if you pick up the right cable at RatShack (has an 1/8" stereo jack on each end - cut it in half, make sure you know what wire goes to what part of the plug, and attach it with the terminal strip). Seriously simple stuff.

Borrowed from Claudio's site:



C

[Paul Ebert]

Who's Claudio and another newbie question

At the risk of being the dunce...

Who is Claudio and where might I find his website?

I, too, am looking to start doing measuring, so this thread is helpful. I really appreciate you veterans helping us newbies out.

There seems to be three or four challenges to mastering measuring. Levels and gating appear to be two of them. How does one, working alone, learn to recognize when these have been set properly?

So much to learn.

Thanks.

Paul Ebert

[Paul H]

Who is Claudio and where might I find his website?

Paul Ebert

Here you go:

http://planeta.terra.com.br/educacao/claudionegro/english/

Paul

[Saurav]

How does one, working alone, learn to recognize when these have been set properly?

Claudio's website will walk you through it. It's pretty important to keep an eye on the VU meter for every measurement. If the number hits 32767, that means you're overloading your input, and your results will be messed up. I wasted time on that until I figured out what was going on. And SW seems to change levels with different signal types. I set them with a sine wave tone, but when I switched to MLS I hit the 32767 limit, so had to adjust levels again.

I just started with this a few weeks ago. It's challenging, but a lot of fun.

[RavS]

Correct...

Thanks, I just ordered the cable!

[RavS]

Uh... the "jig" you need, if you just do the cables, doesn't even require soldering or wiring in jacks if you pick up the right cable at RatShack (has an 1/8" stereo jack on each end - cut it in half, make sure you know what wire goes to what part of the plug, and attach it with the terminal strip). Seriously simple stuff.


C

That doesn't look nearly as bad Well, I have no excuses now!