Understanding Phantom Power, Pre-amps, the Beacktek Adapter, etc - Have an HV30

W

walked

Member
Alright, so I've got questions regarding the Beachtek DXA-4, and the SGM-1X specifically, but this may apply to other discussions.

First and foremost, I've read that the SGM-1X is not a "hot" enough mic to be used without a pre-amp on the HV30. At the same time, I've read that the NTG-2 is hot enough. (just tossing that in for discussion, as the NTG-2 is a second option here).

Where I get a bit fuzzy about specific terminology / what I need precisely is with regard to power.

Both mics are battery powered so phantom power is not required (my understanding is phantom power is to electrically charge the mic for picking up sound by design, not for driving the audio).

However, as mentioned above - the SGM-1X isnt hot enough to get in without a pre-amp and have quality audio. Does the DXA-4 act as a pre-amp? Google says it doesnt require power, and I cannot find any reference that it acts as a pre-amp, yet MANY people have paired the two together. What purpose / actual reason is involved here?

Would I be better off picking up an NTG-2 + simple XLR to 3.5mm adapter, and going without the beachtek instead? I've heard samples that demonstrate both mics as being very impressive. I can also add a beachtek to the NTG-2 later as budget allows / quality requires.

Really, what I'm trying to figure out is how the DXA-4 acts as a pre-amp if its not powered, and what is actually happening. Additionally, if thats the best route to take.


In case anyone needs to know, primary purpose will be using as a boom mic indoors, and some outdoors shots.

Thanks for any insight.
 
You are correct - the DXA-4 is not a preamp. It is a simple XLR to 3.5mmm transformer based adapter with attenuators for level control.

As to the Azden mic I have no experience with its levels so nothing to offer there. I would suggest that a "simple" XLR to mini is not the best way to go with any mic, including the Rode. Even the NTG-2 will be better off with the Beach or a comparable transformer based adapter. I personally like Juicedelink, which IS an active preamp and supplies phantom power as well.
 
I understand that the JuicedLink CX211 is a pre-amp only, no phantom power. The rest of their line does both from what I can tell.

That being the case, I do see a lot of people using the Azden / NTG-2 mics with the DXA-4, and that means no pre-amp. Is the sole purpose of the DXA-4 then to give manual adjustments over the gain control, and giving it a transformer adapter?

Would that mean that compared to the beachtek, an XLR --> 3.5mm adapter with an impendence transformer, the only up side of the beachtek is the gain control?

Just trying to make sure I understand what every piece involved does before pulling out the wallet.

Right now I'm leaning towards the CX211 and the SGM-1X microphone. They should, in theory, work rather well together, no?
 
The purpose of a pre-amp is to raise mic-level signals to line-level for proper recording. No signal that gets recorded is "mic-level." Your camera has a (very rudimentary) pre-amp built in, as the 1/8" stereo mic input is for, as the name implies, mic-level signals.

So getting a converter box with built-in pre-amps is a double-edged sword. On one hand, you get better pre-amps than the camera offers, and the camera's pre-amps don't have to work as hard since the box sends out a stronger signal. On the other hand, the box still sends out mic-level, so the signal still goes through a second pre-amp. Of course, most converter boxes can take line-level in, meaning that you can use professional mixers... but it will still send out mic-level to the camera's 1/8" input.

There are two wonderful functions that the boxes offer. One, the camera's mic input sends out a very low-level power supply for cheap consumer mics. That voltage can cause noise in other mics and pieces of sound gear, so the box is designed to defeat that power supply. Second, as you mentioned, you get tactile level controls... and that's huge for keeping your signals under control.

The basics of phantom...

All sound becomes an electrical charge when it passes through the mic and into the cables. There are dynamic mics and condenser mics. Dynamics create their own electrical signals, as the pickup element contains a metal coil and a magnet. Remember middle-school phy sci where you used that set-up to create electricity? Same deal. Condensers, on the other hand, do not have the coil and magnet, and require an external power source. Phantom, which generally can run from +2v to +50v, provides that. It's called "phantom" because it cancels itself out... or, disappears. And as you know, some mics can run from an internal "AA" battery, or from either battery or phantom.

And I'd get the NTG-2 if it's still workable in your budget. I've never used much of anything from Azden that impressed me.
 
Amen - stick with the Rode. The price difference is only about $75, barely the cost of a movie for two with burgers after these days.
 
Thanks for the insight - very very helpful.

I think rather than fool around with mediocre quality, I'm going to follow this path, as I'm still 100% new with things:

1) Pick up two of these: http://www.amazon.com/Audio-Technica-ATR-35S-Lavalier-Microphone/dp/B00006I51V - this is not for anything real, but just so I can get a bit clearer audio than the on-board mic while playing with things. Again, I'm new wtih things so I've got a few dialogue only scenes I want to film / play around with and these should do just fine until I can get up and running with:
2) Pick up a JuicedLink CX211 + Rode NTG-2 + boom pole and sew my own dead cat together - while I can afford the mic / box upfront, its pushing my budget for the time being, and I'd still need the boom, mic stabilizer, and dead cat + cabling, so I'll wait another pay-period until its all feesable at once.

Reasonable? Any downsides that I'm missing? Am I offbase, taking an unreasonble path, etc?

Thanks so much for the insight so far, again.
 
I really wouldn't bother with those cheap AT lavs, you'd just be throwing money away that you could use in your boom setup. The cost of the two crappy lavs would buy you your shockmount.
 
Thanks for the comment there. I'm mildly curious as to how they perform still. However, at the same time I completely understand what youre saying, and I do try to avoid the whole "penny-wise, pound-foolish" approach to things.

I suppose I'll hold off, a huge part of me just wants a serviceable audio answer as soon as possible, but in the long run youre probably right.

Hey, may as well focus on learning to make pretty pictures until I can shell out on the full boom get-up, no? :)
 
I'll second Jordan to avoid those cheap lavs. Never, ever buy thinking that "it's not for anything real." What isn't real? And what if you do decide to do something "real" in the future? You'll have terrible lavs, and need to spend more money on something suitable. (For the record, I checked some of the customer reviews on Amazon, and any review that includes "equal to any interview I hear on TV" needs to be taken with a huge salt lick.)

You will be much more flexible with a pole-mounted shotgun. And besides, while wireless is a great tool that we use very, very often, hard-wired mics are always more reliable (no dropouts). And Rode makes a very nice zepplin and shock-mount kit. http://www.dvcreators.net/rode-blimp/

And it's even better if you get the mic, pole, and zepplin bundled together: http://www.dvcreators.net/dvcreator-location-sound-package-1/

A good shotgun/pole/mount/blimp kit will be a far more "serviceable" audio solution that will two very-low-end consumer lavs.
 
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RERozak said:
DVEstore's ebay store has a nice CX211/NTG2/Cable package:
http://cgi.ebay.com/Juicedlink-CX21...1QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

-R
Click to expand...

That's prceisely the plan paired with the MS Live cashback. Just going to do this up front + boom pole + shock mount + DIY dead cat.

That should get me in a pretty serviceable spot, no?

I have indeed been pursuaded to avoid the cheap lavs. Like I said, I am generally of the " avoid being penny-wise, pound-foolish" mentality, so its not much of a leap to just skip those.

Thanks for the insight.
 
I used to have it. But DVX user took it off. They also never answered my emails to advertise ... so, I haven't been hanging around much ...
-R
 
And went ahead and purchased the above ebay package per suggestions / advice received.

Just need a shockmount / boom now, but no rush on those really. :)
 
C2V said:
I'll second Jordan to avoid those cheap lavs. Never, ever buy thinking that "it's not for anything real." What isn't real? And what if you do decide to do something "real" in the future? You'll have terrible lavs, and need to spend more money on something suitable. (For the record, I checked some of the customer reviews on Amazon, and any review that includes "equal to any interview I hear on TV" needs to be taken with a huge salt lick.)

You will be much more flexible with a pole-mounted shotgun. And besides, while wireless is a great tool that we use very, very often, hard-wired mics are always more reliable (no dropouts). And Rode makes a very nice zepplin and shock-mount kit. http://www.dvcreators.net/rode-blimp/

And it's even better if you get the mic, pole, and zepplin bundled together: http://www.dvcreators.net/dvcreator-location-sound-package-1/

A good shotgun/pole/mount/blimp kit will be a far more "serviceable" audio solution that will two very-low-end consumer lavs.
Click to expand...

What do you think about the dvcreators store that you referenced? Do you shop there? Have you heard good things? I'm thinking of buying from them, but I want to proceed with caution.

Thanks!

Trey
 
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