# Calibrating the xenyx 802 preamp



## kareface (Jan 30, 2010)

I've read a few conflicting things, some one mentioned not calibrating the preamp, but the majority of the posts I've read said that calibrating the preamp with the sound card is a good idea. This isn't my main question, but I thought I would verify it prior to make sure I've covered my bases. Should I calibrate the preamp with the sound card?

My main question is how should I connect the preamp to the sound card for calibration? Should I use the XLR port the microphone would normally attach to or would simply using the ¼ inch jack suffice? Is the ¼ inch jack below the top left XLR stereo or mono? I assume stereo but I just want to cover my bases. 

Edit: I currently have a simple on board sound card on the computer I'd be using to do the calibration. Would it be a good idea to pick up a USB sound card to use that might be a bit better quality wise? If so which one would you recommend I use if I do?


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

No, mic pre-amps can’t be calibrated because they have a lot of gain (since mics have very little gain). The mic pre-amps built into computers are prone to being noisy and typically have limited bandwidth (i.e. they’re primarily for voices). If you need a mic pre amp, and currently have no sound card, it’s best to go with a sound card that has a built in mic pre amp. The Tascam US-122L is one of the more economical ones.

However, if you’re only interested in measuring your subwoofers, all you need is one of the Radio Shack SPL meters with the calibration file we provide. I.e., no mic pre amp needed, only a good sound card. The pre-amp/sound card combo is only needed if you’re interested in measuring your main speakers as well. If that’s the case, you’ll also need a calibrated mic in addition to the pre-amp/sound card.

Regards,
Wayne


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## kareface (Jan 30, 2010)

Wayne A. Pflughaupt said:


> No, mic pre-amps can’t be calibrated because they have a lot of gain (since mics have very little gain). The mic pre-amps built into computers are prone to being noisy and typically have limited bandwidth (i.e. they’re primarily for voices). If you need a mic pre amp, and currently have no sound card, it’s best to go with a sound card that has a built in mic pre amp. The Tascam US-122L is one of the more economical ones.
> 
> However, if you’re only interested in measuring your subwoofers, all you need is one of the Radio Shack SPL meters with the calibration file we provide. I.e., no mic pre amp needed, only a good sound card. The pre-amp/sound card combo is only needed if you’re interested in measuring your main speakers as well. If that’s the case, you’ll also need a calibrated mic in addition to the pre-amp/sound card.
> 
> ...


I have a calibrate mic (ECM8000), preamp (xenyx 802) and a SPL meter (RS digital) already. So you are saying not to calibrate the xenyx 802 along with the computers sound card? I do plan to do full range calibration with REW. Keeping in mind that I already have a preamp and mic, do you have any usb sound cards suggestions for full range measurements or will the on board sound card suffice? Seeing how I already have the preamp, am I still better off getting a Tascam US-122L? Or is there a better route to take?


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

You should calibrate the Xenyz, just don’t include the pre amp. Use the 1/4” inputs and outputs for the calibration instead. One of our members has tested the 802’s mic pre amp, and it has pretty much dead-flat response, so you don’t have to worry about it affecting accuracy.

As far as a sound card, the Behringer UCA 202 seems to be about the cheapest option these days. However, if your computer’s sound card is full duplex with line-level inputs and outputs, you can use it instead.

The nice thing about the Tascam (and similar units) is that it requires fewer cable connections than the Xenyx / outboard sound card combo. I’d say if you can use your internal sound card, then go with what you already have. 

But if you have to use an outboard sound card, I’d say return the Zenyx if you can and go for the Tascam. It’s only $10-15 more than 802 / UCA 202 combo. IMO the extra cost is justified by the convenience of having everything you need in one package.

Another economical route is the UCA 202 sound card with a cheaper Zenyx 502 mixer. The current models have the needed phantom power the mic requires (older ones did not). That combo would be $20-30 cheaper than the Tascam.

Regards,
Wayne


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## kareface (Jan 30, 2010)

Thank you, I appreciate the input. I'll be picking up the Behringer UCA 202. 8)


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## bjs (Jun 12, 2008)

Wayne A. Pflughaupt said:


> ...One of our members has tested the 802’s mic pre amp, and it has pretty much dead-flat response, so you don’t have to worry about it affecting accuracy....




I have one. It's actually not dead flat due to those pesky little EQ controls (low, mid, high) have some effect even when in the "flat" position. Each channel is slightly different too. I'd say it is "pretty flat" but certainly none of the channels were "dead-flat". Needs to be calibrated for serious use (ie <1dB measurements).

EDIT: Oooops, just realized I read Wayne's comment wrong. I'm talking about the Xenyx 802 in general, while he was referring only to the mic-preamp portion of the Xenyx. I've never tested the mic pre-amp separately so can't comment on that.

As for the OP, why are you are picking up the Behringer UCA 202? Is there something wrong with your onboard soundcard? Most work perfectly fine.


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## kareface (Jan 30, 2010)

2 reasons, first being it's nice to have something that other people are familiar with. In case I run into trouble in the future it's easier to limit the possibilities if I know a specific piece of hardware isn't the potential cause. The second reason is I plan to use this hardware on several computers including a laptop. I was hoping that I could find a decent external sound card just to keep the process as consistent as I can.


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

bjs said:


> EDIT: Oooops, just realized I read Wayne's comment wrong. I'm talking about the Xenyx 802 in general, while he was referring only to the mic-preamp portion of the Xenyx. I've never tested the mic pre-amp separately so can't comment on that.


Actually, that’s good info to know about the tone controls, bjs. After all, it’s all in the signal path. I’m just going by what brucek told me about the mic pre amp in his; I don’t have an 802 personally. Somewhere there's a thread where he posted a frequency response plot of the mic pre, but I can't locate it

I’ve always been concerned about those tone controls, but if they are somewhat engaged even in the détente position, the calibration file should take care of that. I thought maybe using the FX output instead of the main would be a good option, but brucek tells me it’s post fader (meaning all controls in the channel strip are routed through it). A shame, because most other mixers are pre fader, which bypass the channel strip and its tone controls .

Regards,
Wayne


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## bjs (Jun 12, 2008)

Yes, I was disappointed to find the detente position still has some effect given the manual said they are "inactive" in the detente position!

And brucek is right (is he around these days?), the FX send is for devices like reverb, delay etc and therefore post fader. Pre-fader send would mean the effect would still be audible even if the channel fader was zeroed (ie. the dry mix would vary with channel level which most people would find unworkable). I don't know of a way to bypass the tone controls. For REW it can be calibrated out, for live recording one just has to live with it.


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## apinamies (Feb 15, 2010)

If I want to calibrate with the XENYX 502, I connect the line-out from the soundcard to the line-in (below the balanced xlr mic-in) of the 502 and then from the main-out (right channel) back to the soundcard line-in?


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

That is correct. That way both the sound card and the mixer are calibrated. :T

Regards,
Wayne


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## apinamies (Feb 15, 2010)

Wayne A. Pflughaupt said:


> That is correct. That way both the sound card and the mixer are calibrated. :T
> 
> Regards,
> Wayne


Thanks!


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## apinamies (Feb 15, 2010)

apinamies said:


> If I want to calibrate with the XENYX 502, I connect the line-out from the soundcard to the line-in (below the balanced xlr mic-in) of the 502 and then from the main-out (right channel) back to the soundcard line-in?


(Quoting myself) Or use the CD/TAPE out (rca) instead of the MAIN out (trs) as they are supposed to be wired in parallel. I'll try them both to see if they really are the same when compared.


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