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Old October 12th, 2008, 05:18 PM   #1
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Live Music Recording (w/Beachtek DXA-8)

I'm working on a project that involved patching into the SBD Thursday night at the Broken Social Scene show. This was my first time doing it and I can say I've definitely learned the most important lesson of all audio recording and post-production mastering...you can fix quiet, but darn it if it isn't hard to clean up a seriously clipped source. We only got to record one song (thank god, I don't think I'd be able to tackle a whole show that sounds like this). Our audio is just absolutely unusable. So where did I go wrong?

We ran two XLR's from the board to the DXA-8. Then into the camera's (Canon GL1) external mic input. I turned the gain all the way down on both of the Beachtek's channels and turned on the limiters. Neither of the 48v switches were activated. I also had the camera's mic attenuator on and the volume down to about 50-60%. I monitored the audio on a decent pair of studio headphones at the show and I could tell there was some serious clipping, but I didn't know how to fix it? The only thing left to turn down was the volume on the camera and I didn't want to do that during the recording and end up with volume levels all over the place. In hindsight, I feel like that might have been a better thing to do. I feel like even if I had turned down the volume on the camera, the signal was still being overloaded at the Beachtek, then worse it's being amplified before sending to the camera.

My feelings are that the mix coming out of the SBD in a venue like the Vic Theatre are just way too hot to be running through a little device like that Beachtek DXA-8 and then straight into the camera, or are they? Maybe I should've turned the camera volume all the way down to 15-20% and I wouldn't have had the problem. We're going to be doing this again in the future and I want to make sure next time it gets done right. What sort of equipment do I need to get to make it happen, or do I already have the tools in front of me and I need to learn what the I'm doing?

I'm thinking of investing in a set of line attenuators to run the XLRs into before they reach the DXA-8. From what I've been reading on this board, the DXA-8 amplified the already hot signal and that's why I ended up with wretched audio. Either that, or should I ditch the DXA-8 and go for the DXA-4P which has a line/mic switch and won't amplify my audio? Would I still need a set of line attenuators if using a DXA-4P?

If someone could give me some guidance I'd be very appreciative.
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Old October 12th, 2008, 05:25 PM   #2
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One more thought, I don't feel like it's good enough to just have a pair of headphones to monitor the audio with. I couldn't figure out how to bring up a visual on the Canon GL1 to see if I'm redlining.

Is there a cheap solution that might have LED level indicators that would allow me to monitor the audio? Should I run through a small mixer first then to the Beachtek?
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Old October 12th, 2008, 05:41 PM   #3
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Had the very same thing the other night - output from mixer feeding a split to a Sennheiser transmitter (a belt pack one used normally on electric guitars), a DVD recorder, and a minidisc player. The idiot mixing waited till halfway through the first number before suddenly increasing the levels. The cameraman mentioned to me that he noticed the mixer lighting up like a Christmas Tree - red lights everywhere.

MD and DVD recorders waved their hands in the air and gave up - grossly distorted despite being line level devices, one with and one without AGC - the Sennheiser coped amazingly well.

The trouble with most input stages is that the agc comes after the pre-amp stage, so by the time it gets to adjust levels, the damage has been done.
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Old October 12th, 2008, 06:17 PM   #4
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From what I'm gathering the DXA-8 just isn't the right device to be using for this job because it is more of a mic pre-amp and has no way of passing the signal without amplifying it. Is there a better way to accomplish what I'm trying to do?

There are RCA inputs on the Canon GL1, but from what I'm gathering they're for dubbing over prerecorded material. Is there a way I could use those to record from the soundboard? I really need a visual way to monitor the audio as well. Maybe I should invest in a cheap little mixer like the Tapco Mix 6.0. That why I can see if the signal is clipping before it ever makes it to the camera?

Buy Tapco Mix.60 Compact Mixer online at Musician's Friend
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Old October 13th, 2008, 12:19 AM   #5
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Tate, this is this yours? Yes?
BeachTek DXA-8 XLR microphone adaptors for DVcams/camcorders

Tate, I have one of the modest DXA 4p for my XM2
BeachTek DXA-4 Series XLR microphone adaptors for DVcams/camcorders

I could only find/locate the 8 Brochure and instructions right at the bottom of this - I did NOT find them on the BT site:BeachTek DXA-8 XLR microphone adaptors for DVcams/camcorders

From the downloaded instructions : "Set the camcorder to “manual” audio to deactivate the AGC. Turn the gain control on the camcorder to a very low setting – about 20% of maximum."

You say:
Maybe I should've turned the camera volume all the way down to 15-20% and I wouldn't have had the problem.

This could be it? Yeah?

(How about the 9volt battery? Is it good?)

I'd advise that before looking elsewhere, you should really experiment with the advised lower camcorder settings? The downloaded instructions says: "Turn the gain control on the camcorder to a very low setting – about 20% of maximum." - Now I'd say THAT'S a very big hint!

I haven't done Line feeds, but plenty of Mic feeds. And I have my cammie at around 50% - but that IS on Mic feeds.

OK, and I am not an Audio Guru, by any stretch, but hunkering down and trying to get sound tests correct while all about is happening is a big ask. Sound checks, with noisy people and OTHER noises going on is a real problem. If you can do sound checks with "known" factors, in a quiet/controllable environ that is best - yeah? I spend quality time setting my levels and make a real pain of myself JUST to be sure.

I'd also like to draw your attention to that I don't see the 8 being shown on the BT site? However my 4 still is. And if you look back here there is an interesting PINK one liner, it is directly under the heading:BeachTek DXA-8 XLR microphone adaptors for DVcams/camcorders

Also the 8's availability on the B&H site:Beachtek | DXA8 - Dual XLR Camera Adapter with Phantom | DXA8

No, I think that if the downloaded instructions are asking for low Camcorder settings, there has to be a reason? Added to which when I do interviews with Mic feeds, I am down to 50% - and sometimes less - yeah?

Also some FAQs on the BT site for you - it helped me too!:

BeachTek Support...

Grazie
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Old October 13th, 2008, 12:36 AM   #6
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I believe those are the instructions I read before I set it all up too. I overlooked the 20% volume on the camera suggestion! Argh.

Either way, it says that the limiter light should be blinking regularly and they were lit up bright red the entire performance even with the gain knobs turned to 0 on both channels. This tells me that the signal coming out of the SBD was way too hot to be fed straight into the DXA-8. That's why I'm thinking I need a set of attenuators. It all seems counter-productive to me though...Run the SBD mix through attenuators, then re-amplify it with the Beachtek before running to the camera? The GL1 doesn't have AGC from what I gathered reading other threads.

There has got be a better way to accomplish what I'm trying to do here. I'm working with borrowed equipment, so don't feel bad to tell me that DXA-8 isn't what I need for this project. Knowing now that the DXA-8 has no line/mic switch and amplifies everything running through it leads me to believe it's made strictly for microphones. I'm actually wishing I had the DXA-4P because it has line/mic switches and isn't a preamplifier. Want to trade ;-)
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Old October 13th, 2008, 12:41 AM   #7
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"I think that if the downloaded instructions are asking for low Camcorder settings, there has to be a reason?"

Probably because of what I think I just worked out in my head while making my last post. The DXA-8 requires such low camera volume settings because it amplifies the signal. That's pretty much the opposite of what I'm trying to do here.

I'm seriously not attached to it and would love to ditch it. Anyone have any other ideas on how to feed the SBD mix into the camera? I'd rather not do an RCA out from the board to TRS into the camera. That seems a little dangerous to me as well.
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Old October 13th, 2008, 12:47 AM   #8
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Quote:
Originally Posted by Tate Burns View Post
"I think that if the downloaded instructions are asking for low Camcorder settings, there has to be a reason?"

Probably because of what I think I just worked out in my head while making my last post. The DXA-8 requires such low camera volume settings because it amplifies the signal. That's pretty much the opposite of what I'm trying to do here.

I'm seriously not attached to it and would love to ditch it. Anyone have any other ideas on how to feed the SBD mix into the camera? I'd rather not do an RCA out from the board to TRS into the camera. That seems a little dangerous to me as well.
Tate,

The DXA-8 is a mic preamp and you were feeding it with a line level signal. You were distorting the input of the device before sending the signal to the camera. No matter how far you turned it down it was going to distort. You could get two xlr barrel type line to mic adaptors and put them in the lines before the Beachtek. That way you have a nice mic preamp for interfacing external mics to the camera or you can do line level in from the board just by using the mic to line adaptors. If you don't want an active preamp for your external mics you have to get something like the Sign Video box (I have one for my GL2) but make sure it has a switch for line level input. I don't remember if it does. At any rate you're going into a mic input on the camera so you have to be converting line to mic.
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Old October 13th, 2008, 12:55 AM   #9
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Ah-hah. So we're on the same page here. The DXA-4P is pretty much the same thing as the Sign Video Box you speak of. Thank you all so much for helping me sort this out.

I really wish there was an inexpensive device like the DXA-4P or the Sign Box that had LED level indicators. Should I be running the mix from the soundboard to my own little mixer (like the Tapco one I linked above) so I can see if the audio is clipping and make sure I have a clean source before it even gets to the DXA-4P? Hypothetically, at that point is the DXA-4P even necessary if the mixer has 2 XLR channel inputs and an RCA out which I can convert to TRS to input to the camera? A mixer + something like the DXA-4P seems redundant.
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Old October 13th, 2008, 01:16 AM   #10
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Originally Posted by Tate Burns View Post
Ah-hah. So we're on the same page here. The DXA-4P is pretty much the same thing as the Sign Video Box you speak of. Thank you all so much for helping me sort this out.

I really wish there was an inexpensive device like the DXA-4P or the Sign Box that had LED level indicators. Should I be running the mix from the soundboard to my own little mixer (like the Tapco one I linked above) so I can see if the audio is clipping and make sure I have a clean source before it even gets to the DXA-4P? Hypothetically, at that point is the DXA-4P even necessary if the mixer has 2 XLR channel inputs and an RCA out which I can convert to TRS to input to the camera? A mixer + something like the DXA-4P seems redundant.
I think Sign makes a level meter that you can use on the camera but I don't know if it could be used to meter between the board feed and the box. Does your Tapco have line input? Some small mixers don't, then you have the same issue. Line into mic. I wouldn't go rca to trs mini, its too fragile and easy to pull out. The xlr interface whether its active or passive is a handy thing to have to get audio into the camera. Mixer or no mixer. You should be monitoring on headphones from the camera not depending on meters to tell if you're clipping. If they're not loud enough maybe find more efficient headphones that block out external sounds fairly well. (Sony MDR7506, AKG 280, Audio Technica ATH50) If you plug line into mic you're going to have to turn the input controls on the camera almost all the way down and if that's the case you have distortion no matter what. If the level into the camera is mic, then you should have the controls anywhere from 20% to 75% depending on strong the signal is coming from the board.
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Old October 13th, 2008, 01:19 AM   #11
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Nice one Bernie! Spot on.

And the drawback of the 4 is that is doesn't have flashing lights. Trade? NUh-uh!

Actually, one of the reasons I got the Behringer Eurorack MXB1002, 10-Channel Mixing Console with Optional Battery Operation now discontinued, was so that I could multi channel AND see hot spots. Have I seen a "field", in-line LED gizmo, that shows audio levels? The brain cell is failing . . ..

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Old October 13th, 2008, 06:22 AM   #12
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Originally Posted by Tate Burns View Post
...

My feelings are that the mix coming out of the SBD in a venue like the Vic Theatre are just way too hot to be running through a little device like that Beachtek DXA-8 and then straight into the camera, or are they? Maybe I should've turned the camera volume all the way down to 15-20% and I wouldn't have had the problem. We're going to be doing this again in the future and I want to make sure next time it gets done right. What sort of equipment do I need to get to make it happen, or do I already have the tools in front of me and I need to learn what the I'm doing?

I'm thinking of investing in a set of line attenuators to run the XLRs into before they reach the DXA-8. From what I've been reading on this board, the DXA-8 amplified the already hot signal and that's why I ended up with wretched audio. Either that, or should I ditch the DXA-8 and go for the DXA-4P which has a line/mic switch and won't amplify my audio? Would I still need a set of line attenuators if using a DXA-4P?

If someone could give me some guidance I'd be very appreciative.
Just guessing here but I'll bet the FOH sound board was sending you a +4dBu line level signal. Your Beachtek is designed to connect much, MUCH weaker mic level signals to the mic input of the camera. Line level signals would overload the preamps on the Beach with severe clipping being the result.

The Tapco mixer you linked to wouldn't help this particular situation. It accepts either mic or line level on its inputs, so it would be fine with the board feed, but it outputs line level only so you're right back where you started. A mixer isn't a bad idea per se, don't misunderstand, just you need to make sure that you either get one with the option of mic or line output or also invest in some appropriate pads to knock a line level output down to an appropriate level for a mic input on the camera.

The DXA-4P's line level input option effectively gives you a 40dB pad with an adjustable trim, just exactly what you need in this situation. As a passive device it has no internal preamps to overload. The DXS-6vu also can accept line level inputs and has the meters you're looking for. I've been very impressed with JuicedLink's little units - their model 471 has mic/line input selection and a meter as well.
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Old October 13th, 2008, 09:00 AM   #13
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The DXA-6VU looks like exactly what I've been looking for!

Hypothetically, how would I knock a line level down to mic level? Using line attenuators?
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Old October 13th, 2008, 09:11 AM   #14
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Also, would it be possible to run the two XLR outputs from the soundboard to line attenuators that would knock the signal down -10dB, -20dB, or -30dB?

Audio Technica AT8202 Adjustable In-line Attenuator

Then into a an XLR Y adpater-> TRS into the camera. I could then monitor with the Sign VU-150

Sign Video VU150 Audio Level Meter

Would the Audio Technica AT8202's provide enough attenuation to knock the level down coming out of the soundboard? I'm just trying to think out of the box here to save $100-150.
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Old October 13th, 2008, 12:05 PM   #15
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Originally Posted by Tate Burns View Post
Also, would it be possible to run the two XLR outputs from the soundboard to line attenuators that would knock the signal down -10dB, -20dB, or -30dB?

Audio Technica AT8202 Adjustable In-line Attenuator

Then into a an XLR Y adpater-> TRS into the camera. I could then monitor with the Sign VU-150

Sign Video VU150 Audio Level Meter

Would the Audio Technica AT8202's provide enough attenuation to knock the level down coming out of the soundboard? I'm just trying to think out of the box here to save $100-150.
Yes, you could do that but keep in mind that 30 db might not be enough attenuation. Also your set up is clunkier and more prone to failure if you use adaptors instead of an interface box. Up to you but I wouldn't skimp on getting what gets you close to a professional setup for the sake of a hundred dollars or so.
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