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September 6th, 2003, 04:40 PM | #1 |
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cheap portable vu meter
Anyone know of a cheap portable VU meter I could hook up to my XL1s?
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September 6th, 2003, 06:48 PM | #2 |
Wrangler
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Sign Video has one. costs about $130 list.
http://www.signvideo.com/vu150_audio-meter.htm
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September 6th, 2003, 07:23 PM | #3 |
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I have the Sign Video meter and I really like it. I use it with a minidisc recorder, which is funny because it's way bigger and heavier, but I don't want to strain to see where the levels are at. It goes in the hotshoe of the camcorder, giving you a nice flat surface to attach the minidisc with a strip of velcro. Instant, camera mounted backup audio source. It has its own headphone jack, which is a significant boost over the headphone signal of the minidisc (I have a Sony), or the camcorder, but for the size, I think they could have delivered some better quality here. There seems to be a lot more background noise.
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September 6th, 2003, 07:52 PM | #4 |
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I would use the Beachtek SVU-1 or SVU-2. It takes the level's from the Line Out as oppose to the Headphone out and is therefore more accurate, since you can not adjust the output level's.
The SVU-1 monuts onto the shoe, the SVU-2 mounts on the bottom (like the XLR adapter) and also adds a Headphone AMP. http://www.beachtek.com/svu1.html http://www.beachtek.com/svu2.html |
September 8th, 2003, 07:20 AM | #5 |
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I tried the SignVideo VU Meter. it's the worst thing you can use. It takes the audio level from the headphone jack, therefore you are not really getting the true audio levels because you are going through the headphone amp which will output a much higher or lower level that what is really coming into the camera. I found this to be totally useless.
I am now using the Beachtek, which is much better as it doesn't rely on the headphone jack and amp. It takes the audio directly from the audio out on the camera. You may have to pay a little more for the Beachtek VU meter, but it is well worth it. Rob |
September 8th, 2003, 07:30 AM | #6 |
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You calibrate the SignVideo meter by adjusting the volume on the camera (or in my case a minidisc recorder) until the peak on the SignVideo meter matches the peak on the meter of the camera. This is what Jay Rose suggests in his book.
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September 8th, 2003, 07:42 AM | #7 |
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Oh I know how to adjust it. The problem is, if the camera doesn't have a meter then it it worthless to try and use it. Using the headphone output is not a very good way to check the audio levels. Beachtek did it correctly by coming out of the audio out jacks on the camera. Rob
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September 8th, 2003, 08:09 AM | #8 |
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I agree that if the device doesn't have a meter, then the SignVideo meter isn't going to be of much use, but the same can be said of the Beachtek. With both, you're getting a reading after the autogain has done its damage, regardless of whether its coming from the headphone jack or the line out. I suppose if the line out was considered more reliable, you could rig up an adapter to connect the SignVideo meter to it, and then adjust the sensitivity on the meter. I have a GL1, which lacks a meter, by the way. This was the whole purpose for recording to minidisc in the first place. I'm planning to get a cord from A2Z Cables that will split the signal coming out of the XLR adapter and route one cord to the camera and one to the minidisc. My reasoning is that if the minidisc is getting a well regulated signal, the camera will be too. Couldn't hurt. I've yet to actually try this though.
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September 8th, 2003, 10:05 AM | #9 |
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The 'correct' way to set it up would be to send the camera a 0 dB 1 Khz tone and set the peak that way. Or send it a 0dB tone from whatever audio chain you have set up.
Or if you want some headroom in the system, put a known attenuator in the signal and then set 0 off of that. If you have a non-defeatable AGC, then the meter should never get to 0 because that means the AGC is not doing its job. Watching a meter in that case would not seem to be too useful. Kind of like watching the train approach as you are tied to the tracks. :-)))
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May 24th, 2006, 06:09 AM | #10 | |
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May 24th, 2006, 09:32 AM | #11 |
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VU's are not peak meters, they don't show instantaneous readings, they represent more like an "average" reading, wich is better for meassuring loudness, and also, wich is how the human ear really works. In the good ol analog days, VU's were sufficient because analog tape "has" a sort of headroom. You could ride them levels, and the tape would compress the sound a bit, but still sound like something.
Now, you have to keep 2 things in mind. VU's work with references always(OVU always have to mean something), and 2, VU's show average levels, not peak levels, remember that. The problem, and this is were a lot of people get confused, is that all these digital devices (cameras, recorders, etc) have Peak meters. There's no headroom in digital, 0dbfs is 0dbfs, once you go past that there's pure square wave distortion. So this is why Digital needs peak meters, we just can't afford to go above 0 dbfs not even once. What you need to do then is calibrate your VU so that it can work with the limited headroom on digital, and well..sort of trick yourself to create some virtual headroom. First, your VU has to go prior to the input of the camera. Don't measure output, remember we're in digital, if the level is already extreme for the A/D converter at the input of your camera, it doesn't matter, you are efectively already fukd with distortion. Now, what you would do is send a tone through the VU, then, manage or create your virtual headroom. Most folk would calibrate their VU with a tone (1k is common) so that it reads 0VU while you have say -14dbfs, -12dbfs or -10dbfs reading on your camera. Your basically trick yourself by allowing some headroom in your digital gear for the peaks that the VU won't catch, but wich are detrimental for digital. It helps a lot if your audio recording device supports 24 bits also. This way you can keep more conservative levels, and still keep quantization errors way low. So if you're going the VU way, make sure you get one that can be calibrated. Second, get one that can be optimized for different levels. There's a differencie between mic level, pro line level (+4dbu), prosumer line level (-10dbV) Getting a VU that works with the correct format of your camera would be ideal. If your camera doesn't have peak meters...wich it should really, any digital device should have at least a simple led to indicate peak at 0dbfs or above.....Anyway, you can still sense by just hearing. A 1khz sine tone clipping an A/D stage would always sound, well different. And the distortion is instantaneous, it (the signal) either goes above o dbfs or not. |
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