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-   -   Getting good sound in an Automotive Garage. (https://www.dvinfo.net/forum/all-things-audio/480696-getting-good-sound-automotive-garage.html)

Greg Borm June 21st, 2010 12:38 AM

Getting good sound in an Automotive Garage.
Hi Everyone.

I desperately need some help selecting appropriate audio equipment for a video series that takes place in an automotive shop.

I am a custom car builder who is embarking on a project to do a series of ‘how to’ videos on auto restoration and customizing. The video will be shot using a Canon XH A1s in a 30 ft x 30 ft shop with a 12 ft ceiling. The walls and ceiling is dry walled and the floor is cement, so my audio equipment needs to be very good at capturing my voice and avoiding any ‘echo’. Since this room will be dedicated to this project, there will be no other people, etc making noises in the room but we all know how a persons voice sounds when it is recorded in a kitchen (for example) and this ‘hollow’ sounding voice is something I want to avoid.

I will be working alone on this project. The camera will be set up, the ‘set’ lit and the Lavaliere mic attached and a boom mic fixed over my head with no operator. I will then film myself working and explaining what I’m doing to the camera. Recording what I say simultaneously onto the two channels of the sound track, Boom mic on one channel, Lavaliere on the other. This way I can choose the best one in post.

Here’s the question:

I would LIKE to buy and use a Schoeps CMC6 with Mk41, a quality Lavaliere mic (which does NOT need to be hidden, or even small for that matter), all plugged into a Sound Devices 302…. BUT CAN’T AFFORD IT (this package is over $3000).

So, after reading for days on end, buying Ty Fords book and studying it, I THINK a good choice for me would be an Audix SCX1 / HC, a quality Lavaliere mic, both plugged into the Sound Devices MixPre. This gets the cost down under $1500… Aaah… feels much better, but only if it will capture good sound.

Here’s where you, the experienced sound people come in.

Before I make this purchase, could you please take a moment to tell me what you think?

Thank you for your help,

P.S. Since this will get ‘filmed’ as a custom car is built, the project will be recorded a segment at a time, over several hundred days spanning two or three years, so I really cannot hire a professional sound person.

Jon Fairhurst June 21st, 2010 01:31 AM

This is a good challenge - especially with a limited budget. Fortunately, the budget isn't too tight to do a reasonable job.

First, as you note, echo is your number one, two, and three problem. Given that, the recorder is the least of your problems. If you need to hit a price point, I'd be willing to downgrade the recorder to a Tascam DR-100. It's not super quiet, but from your description, you'll be able to get reasonable mic positioning. With a strong voice and all that echo, the noise level in the recorder won't be a problem (it's good, but not excellent), and you don't need silky-smooth audiophile quality at the recorder, since it would all be covered up by the environment in which you're recording. (Note that I wouldn't recommend the Zoom H4n. It has a single volume control, while the Tascam can adjust the gain of the two channels independently.) No mixer is needed, since you'll be working alone. Just plug the mic into the recorder.

For the lav, I'd go with an omni. A cardiod can reduce the high frequencies of the echo, but you could be left with a boomy echo. Also, a cardiod can deliver inconsistent results when you move your head. An omni will be more foolproof. Just make sure to mount it up high on your chest (more signal, less echo) and be careful not to move your head up and down too much when speaking.

On a budget, there's the AT899. My wife uses one for public speaking. It's somewhat large, sounds okay, and is inexpensive. At work, I have a couple of Sanken COS-11Ds (that I use with the DR-100.) They sound fantastic. They have that nice combination of accuracy with a bit of edge - as if it were put through a subtle exciter. Recently, I recorded over 70 people saying their names in a busy, but dead, environment, and they all sounded good and clear. It's small and not inexpensive.

Another option is the Countryman E6. If you don't mind it being seen, this would be even more foolproof. You could keep the recorder on your belt and walk all over the shop without ever worrying about your head position. It would be so close to your mouth that you simply wouldn't have to worry about the echo. On the other hand, I find the E6 to sound quite thin. This is necessary to avoid handing noise and plosives, being head mounted and so close to the mouth. On the other hand, this would help avoid boominess in your echo chamber. With an E6, you wouldn't need any other mic, unless you had a lav as a backup. You'd be totally untethered.

As to a super cardioid, I don't have enough experience with the various models to offer a comparison. I will say that I've read people rave about Oktavas, but the test samples that I've heard don't seem to match the hype. Then again, if you go with an E6 and a backup lav, you'll have no need for a boom mic.

And, of course, anything that you can do to treat your space will be worthwhile. If you will tend to shoot away from a given wall, you could hang moving blankets on that wall. If you have large tool cabinets, turning them at odd angles will help break up standing waves. Moving blankets on the ceiling would help too. Bookshelves (large ones for shop manuals) can help. Space the books unevenly and leave space behind the books to act as a diffuser and bass trap. And, if your shop is somewhat remote, opening the doors will remove some echo.

Best of luck with your project. It would be tough to get soundstage quality, but you should be able to achieve clear, solid dialog without having to mortgage the house.

Romuald Martin June 21st, 2010 06:48 AM

Besides recording technology, check also if you can do something to mitigate the acoustic characteristics of the room. Agree w/ Jon: Eco will be your major problem.

Ty Ford June 21st, 2010 07:07 AM

Hello Greg,

Indeed an interesting challenge. First address the space. The cable TV show Ace Of Cakes is shot in an older building with 12' ceilings. They have attached 2"x 4" foam acoustic absorption panels to the ceiling. Not the entire ceiling, but anything you can do to absorb the sting of reflection helps. You're trying to create a sound stage in a hard-walled raw acoustical space. I have seen facilities with cellulose sprayed on to the walls and ceilings in 2-3 inch layers.

Remember the story about the helium balloons in my book? (thanks for buying it. I am working on a postproduction book now that should be ready by year's end.) You can use fabric, canvass or muslin, for example. It can either be in loose sheets or draped over horizontally suspended poles.

Walls: You can use fabric panels as mentioned above or 4' x 8' panels of Corning 703 cut in any size you want. You may cover them with decorative/colored fabric as well.

Gobos: Gobos "go between" things to block sound. The can be as simple as a C-stand and arm with a sound blanket draped over it. The idea is to make it difficult for the sound of your voice to get to the walls and then difficult for it to get back to the mic. So you build a cocoon of gobos around you, just out of frame.

Floor: rubber mats in as many places as possible. Indoor/outdoor carpeting in less automotive places.

Jon may not have had that extra cup of coffee. I think he may be confusing a Sound Devices 702 recorder with a 302 mixer. The MixPre works as long as your camera has a line level input.

For a mic I would suggest a Countryman E6, hardwired or wireless. In the environment you envision, every inch closer you are to the mic, the better you'll sound.


Ty Ford

Rick Reineke June 21st, 2010 09:38 AM

Unless your going to be absolutely stationary and talking directly to the camera the boom mic track would probably would get little use, and even if it does, it will sound different than the lav so inter-cuts may be an issue.
I'd spend the money saved from a high-end boom mic and put it toward acoustic treatment and a COS-11.

On a budget, there's the AT899. It's somewhat large, sounds okay, and is inexpensive?? ...
-- Not to pick on Jon anymore, but he maybe thinking of a lower priced AT lav. The AT-899 is large compared to a B6 , but in the same price (and size) range as the TR-50 and B3... sounds pretty much on par with those as well, IMO.

Jon Fairhurst June 21st, 2010 10:41 AM

> "...he maybe thinking of a lower priced AT lav. The AT-899 is large compared to a B6"

You're right. My wife has the AT803b. It's cheap, not small, and sounds pretty good for the money, but lacks the magic of the COS-11D. Whatever you get, make sure that you get a compatible XLR adapter. There's no standard for connectors and wiring on lavs. They tend to be pre-wired to work with various wireless transmitters.

The AT803b comes pre-wired for XLR. The AT899 is a more traditional "wire to taste" lav. If you go with a COS-11D, make sure to order it with its own XLR adapter.

One option is to wire the lav with an adapter connector. I wired mine with a TA3. Now I can make adapters for whatever wireless system I might use in the future. The mic isn't hardwired for only one system that way.

You can follow the lav wiring saga here:

Richard Crowley June 21st, 2010 10:42 AM

I would get a good headset mic and a good wireless TX/RX kit. In acoustics like that, you can either do extensive acoustic treatment (which sounds unlikely) or you can maximize the direct/reflected ratio by putting the mic as close to your mouth as possible. Especially in a location that is that reverberant, and with no acoustic mitigation, any kind of boom/room mic seems pointless. If you want ambient, you can just use the mic on the camcorder, that is all it is good for, anyway.

Budget spent on a good headset mic and wireless kit will most certainly be heard in the quality of the tracks. I can't say the same for spending $$$$ on a high-end external mixer. And I just don't even see the purpose of a boom/room mic in your scenario. In acoustics as you describe the boom mic will NEVER be the "best" track, especially as it will be locked down and not tracking you.

If you use a good establishing shot, people will see that your location is a big reverberant box, and some amount of room echo will establish that this is a "reality" production in a real shop, and not on a pristine Hollywood sound-stage. Audiences are becoming more accepting of (limited) audio artifacts that come with low-budget location recording for "reality" type shows. Although even there, it is hardly "reality" when you have a dozen people wearing wireless transmitters (or a couple of very busy boom operators trying to catch everything.)

Greg Borm June 21st, 2010 11:58 AM

Getting good sound in an Automotive Garage: SOUND MITIGATION.
Thanks for all the GREAT info everyone.

Looks like I have two issues: Microphone choice and Sound mitigation.
Since I didn’t address this in my opening post, lets start with SOUND MITIGATION.

I am on board with needing to do something to mitigate the acoustic characteristics of the room. Here’s a brief overview of the ‘stage set’ and my thoughts on sound mitigation.

Behind me:
I will be 5 – 10 feet in front of the shop wall which has had the walls covered in vintage 1940’s – 50’s industrial equipment, cabinets, work benches, shelves, etc. It was chosen so as to NOT be a flat wall of steel cabinets, rather a mixture of differently shaped objects to better disperse sound. (and to be more visually interesting) Like Jon said: “Bookshelves (large ones for shop manuals) can help” I have shelves with differing sized objects on them. I’m also intrigued by Jon’s comment where he said:” Space the books unevenly and leave space behind the books to act as a diffuser and bass trap.” Good advice… I will leave a space behind the objects but should I first cover the wall with some sort of ‘sound material’?

Beside me:
Same as behind me However, I have run a curtain track along the ceiling in front of the cabinets and hung blankets like curtains. I anticipate that I will pull the curtain forward and back adjusting for each shot to cover anything that is not in the shot. I think this will accomplish what Ty said about:” build a cocoon of gobos around you”

In front of me:
The camera and lights will be in front of me, Behind them (still in front of me) will be more blankets hung from the ceiling. In this case I anticipate leaving spaces between the blankets to prevent the creation of a full fabric box. Am I correct in thinking openings in this curtain will control echo better and result in better sound (kind of similar thinking to leaving spaces behind objects on my shop shelves discussed above)?

Above me:
The ceiling is 12 feet above me and hung from the ceiling is a radiant heater (think of a very hot metal tube 6 inch in diameter running across the ceiling above my head) I cannot cover it, but in the remainder of the ceiling I was thinking of acoustical ceiling tiles of some sort. Near the heater I need to use something FIRE Rated, like those t-bar ceiling panels used in office buildings. The commercial ones are rated for use here since they can be purchased in a ‘fire proof’ grade, but what about the sound? Are office t-bar ceiling tiles a good idea? What about the ceiling that is safely away from the heater? Should I use the same tiles or is there a better choice? To cover the entire ceiling would be 900 square feet, but realistically, I would likely do the 400 square feet above my head.

Below me:
Lets cover the cement floor! It will have to be something that can be readily placed and removed. I will be cutting with a torch and welding, so I will need a cement floor at that time. I was thinking of several products: 1) Black floor foam tiles. Building places like Home Depot sell these foam squares meant to go on the floor and make it nicer to stand on. I could buy several hundred square feet of this to cover the floor. 2) Carpet roll ends / used household carpet. I could take household carpet and cut it into smaller pieces that could be quickly moved in and out as needed. 3) Well… any other options? A concern in this choice is color. Off white (soon to be dirty white) would reflect light better. Is this a concern? The floor coverings will always be off camera when the floor coverings are in place.

Oh Yeah, BUDGET for sound mitigation. Lets say $500 doesn’t scare me, AND this discussion is slowly talking me up to $800 or more.

Any advice? Ideas on techniques and specific materials to use would be GREATLY appreciated.

Thanks again everyone,

P.S.: I also like Jon’s idea: “if your shop is somewhat remote, opening the doors will remove some echo.” Unfortunately, this garage is in a quieter part of town, but I would definitely get intermittent traffic noises, so I think that is out.

Greg Borm June 21st, 2010 01:19 PM

Getting good sound in an Automotive Garage: MICROPHONE CHOICES.
In my last post I got serious about sound mitigation. Nonetheless, I still need to choose some sound gear.

BOOM MIC…Do I even need one?

Rick Reineke made a comment that really resonated with me: “unless your going to be absolutely stationary and talking directly to the camera the boom mic track would probably would get little use”
Good point. The words ‘Absolutely stationary’ do not describe what I’m going for. Especially when Rick added “it will sound different than the lav so inter-cuts may be an issue.”

Additionally, Richard Crowley built on this comment with: “I just don't even see the purpose of a boom/room mic in your scenario. In acoustics as you describe the boom mic will NEVER be the "best" track, especially as it will be locked down and not tracking you.”

So… NO BOOM MIC? What are every body’s thoughts about this?

I’m not real keen on the ear mounted Countryman E6. I don’t mind a lavaliere being seen on my shirt. Indeed, it is expected in this sort of video. None the less, and maybe it’s just me… but I personally see this sort of headgear more appropriate for an aerobics video, or a pitchman like Billy Mays. Hummmm… I may need to change my opinion here. Until that happens, lets discuss my other options.

Well it looks like my Lavaliere Mic choice will be very important.
On your advice, I had a look at the “Sanken COS-11DBP Omni directional Lavaliere Microphone with XLR Connector (Battery or Phantom)” and although $450 is high, the price isn’t bad.
In another post, Ty Ford also recommended “Countryman B6 Omni directional Lavaliere Microphone”, at $330 this also interests me.

Any input / advice? If the lavaliere is going to be my main microphone… it had better be a good one… or should I say, one that is awesome in my garage environment… So it looks like I need a little more guidance here.

What about Pre Amps / Mixers like the Sound Devices 302 or the PreMix. Since I do NOT have a sound man in this one man show, and every shot is planned, set up and executed by me… I do not need ‘on the fly’ sound adjustment. Nonetheless, although I don’t need these devices for their usual “sound man purposes” … What about using one just because they have better electronics in them than my a Canon XH A1s has. My reasoning is the by using line in levels in my XH-A1s I can bypass my XH-A1s preamps entirely and thereby improve the sound because I am now using the better electronics in the Sound Devices 302 / PreMix unit (in place of the reportedly poor ones in the Canon XH A1s).
What are your Thoughts on this?

THANK YOU AGAIN for reading my post and offering your guidance. It is DEEPLY APRECIATED!


Richard Crowley June 21st, 2010 01:35 PM

I am dubious about using a lav In the kind of acoustics you are describing. You want the maximum ratio of direct (mouth) to reflected (ambient) sound. The 12 inches difference between clipped to your shirt and next to your mouth will make a huge difference in your ambient situation.

I also think your reticence to using a headset mic is misguided. You see them everywhere, both in scripted drama, and in real life. From Sunday morning pulpits to Sunday afternoon pit crews and the crew of Stargate Atlantis. The very tiny tubes (which are available in a variety of completion-matching colors) are practically invisible except in a CU shot.

I don't know how much practical acoustical mitigation you can do with $500, IF you want to keep it LEGAL and SAFE (i.e. fireproof). There are all sorts of things you can put up for temporary sound absorption, but none of them are recommended for (semi-) permanent fixed installation, especially in a hazardous location like an auto garage or machine shop or similar industrial setting.

Regardless of what mic solution you select, I think the acoustics of your location will completely swamp out any potential benefits of a premium mixer or mic preamp. So shoot some test footage plugging the wireless receiver directly into the camcorder and do some critical listening for yourself.

Note that the only way to bypass your (or any) camcorder's built-in mic preamps is to not use them and record elsewhere. The "line level" inputs on camcorders is merely a pad to knock the line-level back down to mic level. IMHO, in your scenario an external preamp is a misuse of your audio budget.

Jon Fairhurst June 21st, 2010 03:35 PM

Even though Richard and I are in the same geographical area, I'll offer the counterpoint opinion... ;)

Given that you will be doing some sound treatment, you *might* be happy with the lavalier. (You wouldn't be happy in an untreated, empty space.) Of course, the E6 would offer less echo, but as I mentioned, it's a thin sounding mic. And you don't need to have zero echo. As long as the reflections are natural, not too strong, and your voice is clear and understandable, you're fine.

I think this is a judgment call. The E6 is lower risk as it can be clinically clean and won't vary as you move your head. With a lav it's hard to know when you cross the line from good, natural sounding dialog to amateur echoey dialog. Done right, the lav can make it more "authentic", while the E6 could be a bit sterile. Assuming that your room treatment is adequate, it's a style decision.

Regarding a high-quality preamp/mixer ahead of the camera, that can definitely improve things. Feed the camera with a strong signal and turn down the camera gain for a clean result. Frankly, I don't believe that noise will be an issue for you. You'll have a nice strong signal with close mic placement and won't have to boost things in post. Signal to noise is much more important when recording quiet sources, or when you're recording over some distance. Dramatic whispers and moments of silence can be challenging. But for a custom car build, you'll be speaking pretty consistently when on camera.

That brings up something else, what about natural shop sounds like compressors, air wrenches, welding torches, etc? It would be nice to have a stereo mic for these sounds. Note that unlike dialog, you can record these separately from the video and add the sounds in post, if needed. Of course, a live recording is the most efficient use of time - if you can position the mics well enough to get a good result.

For these sounds, a stereo recording is best. I'd go with an X-Y setup to keep things simple and avoid phasing problems. You don't need a fantastic mic for such recordings, but you want something that can handle high SPLs. A pair of SM57s (often used to record electric guitars and snare drums) would do the trick. They don't have much at the extremes of the frequency range, but that's a good thing for shop noises. They're also nearly indestructible, affordable, and have been around forever, so you might find them used. The trick will be to get them near your work, yet hidden from the camera.

Best of luck with the project!

Richard Crowley June 21st, 2010 03:56 PM


Originally Posted by Jon Fairhurst (Post 1540843)
Feed the camera with a strong signal and turn down the camera gain for a clean result.

Agreed. But note that if your mic signal is coming from a wireless receiver, you can typically turn it up as "strong" as you like, even line-level on some receivers. External mixer is superfluous for the purposes of simple gain enhancement. In fact, again, wireless receivers typically have line-level outputs and simply insert a pad to produce mic-level output.

Dan Clark June 21st, 2010 05:23 PM


While I'm not really qualified to give advice on capturing audio, I have a little experience with Lavs and have two concerns about using a Lav in your application - clothing noise and big changes in audio volume. From working on cars from my younger years, I remember contorting myself into weird positions. If that describes your situation, you might find the lav shifting position. It could be moving away from and toward your mouth, and picking up clothing noise constantly.

For example, if you lean forward to demonstrate attaching a fender, wouldn't the Lav suddenly swing up towards your mouth? Or if you twist around in a back seat won't the Lav pick up a lot of clothing noise?



Allan Black June 21st, 2010 05:45 PM

We're shooting similar projects restoring historic airplanes in large hangars. We spent time getting stereo fx tracks with reverberant air compressors, tools and off camera voices to build up the mono voice tracks. You can even include a still photo of a plane and the hangar sounds as busy as blazes.

So don't kill the reverb too much, get a few roll around office dividers stick some acoustic foam on 'em and place them just out of frame.

We use Sony ECM77 omni lavs and occasionally a boomed NTG-3 with an op to the camera.

But if you're hoping to sell this and even though it's a long project at least use a camera operator.

If you don't it just won't work it's too restricting and you will end up with unusable footage resulting in frustration and wasted time to the point where you give up.


Chad Johnson June 21st, 2010 06:34 PM

My take:

I'd say skip the boom mic. Get a sennheiser G3 wireless, and a Sanken COS11d lav. Total 1,200.00. Go straight into the camera. If you feel you need a boom mic after you test with the lav, buy an AT4053b, which is a hyper. Don't use a shotgun in that reflective situation.

Just try the lav. Or get the COS11d, with a 100.00 power converter (to convert phantom from the camera to a power the lav can use), and go wired to the camera. That will save you buying the wireless, but you may find you like the freedom of being wireless.

With the lav you will have the mic consistently at the same distance from your mouth, giving you consistent audio. That's important since you will have nobody monitoring your audio. Deal with the room reflections with some moving blankets from Costco, at about 8 bucks a piece.


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