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AutoCal -- Use a GOOD microphone


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You will need one that is:

 

1. Omnidirectional.  DO NOT use a cardiod pattern mic!

 

2. Has a TR/2-conductor plug.  This will be the hard part.  MOST good mics have a THREE-conductor plug (either TRS or XLR) because they want power (for their capsule) from the device they're connected to.  You need either to provide that and then feed the head from there on a 2-conductor plug or have a mic that has its power (and battery) inline or in the mic itself.

 

The "CD-MC20" that Pioneer sells is IMHO trash.  I got my fancy gear out and checked it.  It's not linear at all.  Blech.  Then again, for $20 I guess it's not THAT bad -- but I sure wouldn't mic someone up with it and expect good results.

 

So I plugged in a nice-quality (not one my best A/V Sennheisers as I didn't have the necessary interconnects to get it power yet not feed a high-level signal out of it, but one of my "decent" lavs that I have in my bag of tricks for times I can't use phantom power as the thing I want to feed doesn't know how to provide it) mic to the head unit and ran the auto-cal.

 

Talk about waking up the mid and high end..... the result was VERY nice.

 

Most people after trying the "auto-cal" will find it flat and lifeless if they use the MC20 -- this of course leads everyone to say "just do it manually."  The problem is that unless you have a pink noise source and 'scope you CAN'T do it accurately manually, and the head has no provisions to manually set the EQ for the front and rear speakers individually, but it appears it DOES when you run AutoEQ.  So find someone with a real mic and run it again, then tweak THAT if you want.  The goal is to flatten out the base frequency curve to account for the acoustics in the car, then modify from there if you want for how you'd like it to sound.

 

Incidentally the time correction is worth it, even if you manually set the EQ, so if all you have is an MC20 use it for the time correction and then shut off auto-eq leaving the time correction on.

 

One other thing to be aware of is if you have a sub get anything under 100Hz off the door speakers.  It will do wonderful things for midrange clarity.  The head seems to like to set the crossover for the sub around 80Hz or so.  You'll win big in the clarity department if you move it up around 100-125, and check the phasing on the sub when you're done because the head will get that wrong a good part of the time too.  With the MC20 is often will decide to leave the HPF off with the door speakers, especially in the front -- that's a bad idea in general.  If you move the crossover frequency up you will probably need to also dial the sub's output down another db or two, but that's a matter of individual preference.

 

Enjoy.

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That's a stereo unit - you need a MONO microphone for this.

 

An omni lav works great IF you can find one that doesn't need phantom power.  Most good ones do.  The other option is to take it into whatever mixing or other preamp device you have that can feed it phantom power, pad it down enough to be ok for the head unit to use the output (you may need an external pad for this) and use that.  That'll require a bunch of wires and such.

 

I have a bunch of Sennheiser lavs along with some larger stuff for video production use (e.g. on-stage, presentations, bands, etc) and happened to run across a little lav 4 or 5 years ago that I keep around for the odd situation where I can't get phantom power for some reason (e.g. someone has a camcorder or other device that wants a microphone-level input but it's a "consumer" style device that doesn't know how to feed power back.)  It uses a button cell for power and is a simple tip/ring (signal/ground) output rather than the usual TRS or XLR setup.  Tried it on a lark when I noticed the MC20 had a TR plug on it (can't hurt anything) and -- voila!

 

I wouldn't BUY one for just this purpose, since you'll probably use it exactly once.  Radio Shack has a a little omni electret lav they sell that has an inline battery and is suitable for this -- it's going to be much better than the $20 Pioneer, but still isn't going to get you all the way to what appears to be possible.

 

The IDEAL situation is if you can find someone who has a GOOD omni condenser with either a built-in battery or the power box to feed it, and can output to a mono (2-conductor) mini plug.  Most pro stuff goes out to XLR, but most folks also have a balun sitting around for exactly this sort of reason -- someone needs fed audio and can't eat their XLR. Most-commonly they have an XLR-1/4" balun but that's easily adapted if so.

 

Now that I know the head unit ISN'T balanced for that MC20 but really would like to eat quality input I'm going to go to the trouble to rig up one of my Sennheisers and see what that does.  Although frankly I don't know I'll get a lot of incremental improvement over what I got already -- the difference was shocking just going from the MC20 to the $50 electret -- I suspect rigging the $300 mic won't make that big of a difference by comparison -- although I could be wrong.

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Thanks for the reply. THis mic takes a battery so no phatom required and it is reall dual mono output with two of the same drivers.  I have all the cables needed. Ill give it a try some time and post a comment. I do have sm58s and 57s but I would think it wants something with full dynamic range like the audio technica.

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The SM57 and 58 are both cardoid pattern; you do not want that because the unit measures the rear speakers as well and the cardiod pattern is going to attenuate the sound coming from the rear.  I would expect to get quite-bizarre results using those.  I have several cardoid lapel mics that are excellent for presentations since they cancel room noise quite-effectively but they're the wrong tool for this job.

 

I don't know if your best option for the AT would be to wire the cable to be additive (e.g. short both channels signal together on tip plus common ground) or whether you would want to use one channel only and hang the mic so that element faces forward on the headrest.  I think I'd try both and see what works better; the concern with using it additive is whether you could get an out-of-phase cancellation between the elements electrically during the timing measurement which would throw things off.

 

The response curve on that mic looks pretty good - you might wind up needing to dial in ~3-6db of cut on the 13.5Khz eq with this when you're done, but other than that what you get should be nice and flat.

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The SM57 and 58 are both cardoid pattern; you do not want that because the unit measures the rear speakers as well and the cardiod pattern is going to attenuate the sound coming from the rear.  I would expect to get quite-bizarre results using those.  I have several cardoid lapel mics that are excellent for presentations since they cancel room noise quite-effectively but they're the wrong tool for this job.

 

I don't know if your best option for the AT would be to wire the cable to be additive (e.g. short both channels signal together on tip plus common ground) or whether you would want to use one channel only and hang the mic so that element faces forward on the headrest.  I think I'd try both and see what works better; the concern with using it additive is whether you could get an out-of-phase cancellation between the elements electrically during the timing measurement which would throw things off.

 

The response curve on that mic looks pretty good - you might wind up needing to dial in ~3-6db of cut on the 13.5Khz eq with this when you're done, but other than that what you get should be nice and flat.

thanks will post results once i find the cables in my box, by the way I got horrid results using the pioneer mic that came with my elite reciever

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What mic did you use? What would you recommend?

 

I have an omni lav in my gear bag for video work that is relatively cheap, a no-name but came with a response curve that's pretty flat out to 15khz or so and down to ~50hz or thereabouts.  That's what I used.  Radio Shack sells something pretty similar to it for $40 or thereabouts but I don't think I bought it from them -- it's been in my bag for a good while, and isn't a name-brand.

 

The key is that it has to not only be flat in frequency response and omni (NOT a cardioid pattern!) but also must have a 2-pin output -- the TRS (3-pin) will NOT work because those want phantom power from the device that they're plugged into.  This one has a little box on the wire with a little hearing-aid battery in it for power, so it doesn't need an external power feed.  That's why I bought it -- for the situations that are rare but non-zero where I need to mic someone and can't use one my Sennheiser body packs or similar that can provide phantom power to the mic.

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I'd like to try the auto-cal procedure on my NEX-8000 with something better than the CD-MC20.  However, I don't know anyone that's got something better that I could borrow, so I'll have to buy something.  I, too, have no idea what to buy even with all of the suggestions given thus far in the post.  Could you put up a couple of specific links, maybe for some mics in the $50 to $100 range that should work well.  It seems a very reasonable amount to spend if it will make the NEX-8000 sound noticeably better.

 

Looking forward to trying out a sub crossover setting above 100Hz.  I think the auto-cal set mine to around 80Hz.

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Not worth the money IMO you can adjust the eq and get it to sound great also good to really tweek the crossover if you have amps, if you dont have amps you will never really tap the potential of the head unit

 

If you used the mc20 I would forget useing the auto EQ turn it off an just use the EQ, I just brought my sub xover point to 125 from 100 and now the kick drum is much more intence

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Doing an adjustment by ear will not work correctly without a pink noise generator. 

 

Use this post for more info on doing it correctly. 

 

http://carstereochick.com/blog/2012/08/09/how-to-properly-set-an-equalizer-in-a-car-audio-system/

 

I did use the Audio Tools app for iPad and got really great results. 

 

I'd love to find a good mic to do it automatically as well. It's not so much the mic, but the connector. If the unit doesn't recognize the mic you wasted money for nothing. Links would be great. 

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The head unit has a built-in pink noise generator.  That's what that noise is that it generates during the auto-cal process.

 

As I noted Radio Shack sells an omni electret mono microphone with an inline battery (their part 33-3013) that will be MUCH better than the MC20.  It's not exactly a high-end device but it'll work, it's miles ahead of the MC20, and it has the required 2-conductor plug.  One note is that the current picture I see online looks different than what I've seen from them before.  Whether that's a packaging change or the actual microphone is different I don't know, but it does have the 2-conductor plug and is self-powered.

 

If you get something like this http://www.bhphotovideo.com/c/product/944398-REG/polsen_olm_10_omni_directional_lav.html that will also work (note the self-powered part -- that's the important part) BUT that has a "TRS" (as opposed to TR) plug.  In other words, "dual-mono."  You will need an adapter cable that shorts together the tip and ring (first and second rings on the plug) and combines them to the tip, passing shield to use with one that has the three-conductor plug.  Ditto if you have something with a the required battery box but has an XLR output -- you'll need an adapter cable.

 

A mic that is NOT self-powered will not work because the head unit cannot provide phantom power.

 

Note that you do not want one with low-frequency roll-off.  Mics intended for lav use sometimes have that included to try to keep rumble out of the signal; it's undesireable for this application for obvious reasons.  The amusing part is that as you go up in price you have to pay close attention to that; I have a Sennheiser here that is utterly awesome for presentations and such but it has a response curve with it and there's an intentional roll-off in its response below ~150Hz or so, which makes it totally unsuitable for this use.

 

Most mics have a roll-off above about 10khz; what this means is that when you're done you will probably want to dial in ~3db of cut on the 13.5khz band, or maybe 6db there and 3db in the next one down.  Remember that what auto-cal is going to produce is "flat, as the receiver sees it", so if the microphone has a roll-off at high frequencies they will be "hot" in exact inverse to that.  Ditto if it has a roll-off at the very low end.  This is why a lav with a 150hz roll-off is undesirable; it will result in grossly-boosted bass response.

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I think we need to determine if the settings suck or if they are not what's preferable to your ear. We all have our own taste and some of us might like deeper bass, while others may want a little more highs. 

 

I'd be interested to see if we could run pink noise through the unit after two mic's are tested to and use the graph in Audio Tools to see if certain frequencies are not being picked up or are off a little when compared to another mic. 

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