Need Suggestions For Capturing Train Audio

Jay Massengill · March 29th, 2011, 07:17 AM

I would try the AT8022 stereo mic for about $359 online. It can be used either as balanced XLR or unbalanced mini-plug, as well as phantom or battery powered.

I'd also add this shockmount for $50:
http://www.bhphotovideo.com/c/product/554681-REG/Pearstone_DUSM_1_DUSM_1_Universal_Shockmount_for.html
And add suitable furry wind protection. Stereo mics using one large grill tend to be very sensitive to wind noise.

Scott Hiddelston · March 29th, 2011, 11:58 AM

Thanks everyone for some great advice here. Greg, I am ordering the Behringer ECM8000 today. I will take that along and try it as soon as it arrives. My nearest railroad is 30 miles away, and trains are a bit infrequent, which is why it's difficult for me to use one train to calibrate and then wait for more.
Steve, those are fabulous audio and video tracks. In your youtube video, I'm really impressed with your capture from 5:39 through 7:03. the train can be heard clearly from approach, yet no distortion from the horn even up close. That is what I'm looking for, along with the laboring sound of the locomotives on a stiff climb.
You guys have lit a fire under me now, and I am going to spend more time getting this right. Thanks !!
I will report back with any results. While I wait for the omni mic to arrive I will stop using the limiter and try and get some kind of feel for where my settings should be using my AT 875R.

Greg Miller · March 30th, 2011, 07:32 PM

Jay:

It's interesting that you'd suggest the AT 8022. I have one of the two predecessor versions, the unbalanced AT822. I thought I'd try that as a minimalist approach to train recording. (Of course I'll have to check the headroom specs first, especially since it's powered by only 1.5 volts.) I will probably also take a pair of A/T small omnis, and maybe a pair of cardioids just for comparison.

Scott:

Let me know what you think of the ECM8000. I hope I haven't given you bad advice, but I have read some good things about that model, and it's certainly inexpensive enough. If you like the sound of one, do consider getting two; I really think stereo will help your "audio illusion."

• Does anyone else have any experience with the ECM8000? Please post your findings!

I, too, am about 30 miles from the main line (in Altoona) but I think the trains there are fairly frequent. I surely hope so because I'd like to try numerous takes when I go there for a day trip.

I am still pondering the correct "perspective" for trains. On the one hand, I like the real feeling of power from the engines, which seems to be captured best at close distances. On the other hand, close distances create a little too much stereo spread for my taste... the train approaches fast, is close and loud for a second or two, then zooms into the distance. I would like the "fullness" to last a little longer.

I realize some of these videos are made from perhaps 30' from the track, and the perspective I've heard is probably realistic for this distance. But I suspect it would be more pleasing to me if the train sounded close for a longer period of time. (Or do people get a "rush" from having the train zoom past so quickly?) Again, I think recording from the inside of a curve would help with this goal. (Sort of like the old visual trick of filming someone running through the woods, using a stationary camera on a pan head, having the actors run in a circle around the camera so the distance remains constant.) I will have to ponder this further.

Maybe this thread will pick up as the weather gets warmer. Keep us posted!

Battle Vaughan · March 30th, 2011, 11:16 PM

Puttin' on my other hat as a volunteer machinist at the local railroad museum, let me suggest that locos are BIG---and they make different noises in different places. The 15 ft height suggested is great for detail on the diesel engine, which makes distinct noises from, for example, the valve assembly at about chest height if you're on the catwalk of the engine. And the horns, exhaust and such, are all pretty high up.

On the other hand, the sounds of the trucks on the rails, the air brakes, various squeaks and rattles, are pretty much assoicated with the lower parts...the electric motors which drive the wheels are set low. I can see, if shooting close-up, a two-tier mike system would be good.

Steam locos have lots of moving parts and different sounds from front to back as they pass, as well as from high to low on the loco and present a real challenge, I think.

The farther you get from the loco, the more detail is lost and the more the sounds become sort of a heavy rumble at low speeds. At high speeds, at a distance you can get the doppler-shift sound as the train comes nearer then goes away, but lose a lot of the rail sounds.

Scott Hiddelston · April 29th, 2011, 09:28 PM

Hi All,
I have had a couple of weeks to try out the Behringer ECM8000, and I have to say that for $50 it does an admirable job. Compared to the AT875R I was using, the Behringer has a slightly more muffled sound, and high frequencies are not as crisp as the AT. But at 1/6th the price the Behringer is an excellent alternative.
I found the Behringer to be less sensitive. Now I know the term "sensitivity" may mean something significant to you audio experts out there, but in my limited knowledge I mean it to be how sensitive the meter reads when sound appears. In this instance the AT is much more sensitive to changes in audio levels, and the audio meter dances up and down way more than the meter that's reading the Behringer. In some ways that would make the Behringer a better choice for me, but when I compare the two I can't let go of the crisp high frequencies out of the AT, especially when the train air compressors let a blast of air out. That's where the AT shines.
But I have to say that neither of these mics, or for that matter ANY mic, is going to solve my problem. Because with my Panasonic HMC40, I can only guess at the best setting for any mic, and hope it doesn't get overloaded. Trying to turn down the little wheels on the XLR adapter would not only jolt the camera, but probably overload my brain functions and ruin the shot. Kinda like rubbing your tummy and patting your head. So is there any way I can buy some kind of machine/attachment/device that does record high quality sound, but also automatically adjusts gain to get good audio at a distance but compensate automatically as the train nears and the sound rises? Field mixer with auto gain perhaps?
I understand that to the purists what I am looking for is not real true audio. But for my needs I want the sound of the locomotives to be dominant throughout the whole shot. From approach, to pass and to receding. Thanks for all your help.
Scott

Greg Miller · April 29th, 2011, 10:27 PM

Hi Scott,

Glad to hear you're still "on track" with the project (pun intended).

Very interesting observations. You hear a "brighter" sound with the AT, and that corresponds to the difference in frequency response. Look at the two graphs attached, showing output level (vertical scale) versus frequency (horizontal scale). Notice that the vertical scale on the two graphs are not the same. The AT875 has a peak of around +4dB, from around 4kHz to 7kHz, while the ECM8000 has a peak of around +2dB and a much smoother peak at that. So yes, the AT probably sounds brighter. Also, the AT has less output at the very low end, which shifts the frequency balance higher... again sounding a bit crisper.

What you call "sensitivity" is not quite the usual definition. However, I understand what you're saying. I can only offer some guesses here. The AT is very directional so it is picking up different sounds as the train goes past; the Behringer is omni so the sound it picks up does not change as much when the train passes. Also, lower frequencies tend to be more constant in level (over a short time); higher frequencies bounce around more, and the AT is slightly more sensitive to high frequencies. All this could explain why you see the levels bouncing around more with the AT.

Certainly you can buy a separate audio recorder, with good metering, switchable AGC, and switchable peak limiting. You will need one that supplies at least +11v phantom power to the mic, so that will elminate some of the less expensive recorders. Zoom makes a few which seem to be well regarded, the H4n (which even has a nice stereo pair of mics built in) is around $300; there are others upward from there.

I would advise against using AGC, as it will try to make the level uniform. That will sound unrealistic, as the train is much quieter when it's 100 yards away than when it goes past 50 feet away. I have heard some bad train recordings where the whistle blows causing the AGC to lower the gain significantly. As a result, while the whistle is blowing the sound of he engine becomes extremely quiet; when the whistle stops you can hear the AGC quickly "turn up the level" of the engine. VERY unrealistic.

I would suggest you set your level when the train is at its loudest... the nearest distance and with the whistle blowing. Adjust gain so you are recording at around -6dB. Then don't touch the gain control after that. You could also turn on peak limiting (if available) and that will protect you from clipping if the sound increases unexpectedly. (Peak limiting is quite different from AGC.)

Perhaps some other folks will jump in here with recommendations for specific recorders.

Meanwhile, if you do get an H4n, please do try recording in stereo... just use the integral mics... and see if that doesn't sound much more realistic than a mono recording does.

Thanks for the update, and please keep us posted!

Scott Hiddelston · May 2nd, 2011, 10:21 AM

Thanks Greg, and all others who have contributed to this.
I have looked at the Zoom H4n, which seems very nice. I also had a look at the Marantz 661, which is considerably more expensive. However I happened to see the AT 8022 that Jay recommended. Both the Zoom and the AT are comparably priced. So here I go with more questions.....
Should I buy the AT 8022 or the Zoom? I have no need for an external recorder other than accompanying my video camera, and it would add the additional task of importing and syncing external audio, but would it be a better choice than just adding an AT 8022 to my camera and XLR adapter? Would one be better sounding than the other? I can try either (or both) and return if I don't like, but any advice would be appreciated. Thanks again for following along with this!!! I have to go out this morning but later I will post some audio files from train video I took Saturday.

Scott Hiddelston · May 2nd, 2011, 05:09 PM

Here are three attachments of the same event taken last weekend. I'd like to ask you guys what you feel about these clips, which ones sound better and any obvious flaws you might hear.
The Behringer ECM800 and the AT 875R were plugged into the xlr adapter on my video camera. The Sanyo Xacti was on its own tripod and contrary to the other two, did not pan to follow the train (I only have two arms). However I wanted to include it since I think I hear a definite benefit to stereo. None were normalized or altered in any way, just exported from the original clips in wav format.

Greg Miller · May 3rd, 2011, 10:16 AM

I wasn't there, and I haven't listened to trains for many years, so it's hard for me to say which one is most realistic. All three recordings surprise me in that there's a lot less of the exciting "close detail" sound than I would have expected. But again, this is based on my hearing trains fairly close up, and decades ago. So this is more of a comment on my personal train memory, rather than on the accuracy of your recording.

I notice the two single-mic recordings have a fair amount of level fluctuation... presumably caused by multiple engines going past, or by your panning the mics. The Sanyo recording has very constant level, so I would guess that recorder has a lot of internal AGC, which will tend to make the recording un-realistic.

The response of the two single mics is as expected, based on the published curves. The Sanyo has more midrange and HF information (from about 500Hz to 6kHz), compared to the two real mics. I would guess its response curve is tailored to improve speech intelligibility. But again, this deviation from flat response will make for a less realistic recording.

The Sanyo recording has very little stereo information... it is almost purely monaural. I don't really consider that to be a stereo recording. Either it was very far away from the train, or else the "stereo mics" are disappointing. I don't really have any info about your particular Sanyo, but many times internal "stereo mics" are omni capsules, and in that case they will not capture a decent stereo image if they're more than a few feet from the sound source.

Out of curiosity, how far were the mics from the track? I have read some interesting theories about stereo recording. One such theory states that coincident cardioids (X-Y pattern) capture a good stereo image when fairly close to the source, but as distance increases, increased spacing between the mics is necessary to get a good stereo image. (This is analagous to the way really powerful binoculars have increased distance between the optics, to produce a good stereo visual image at really far distances.) If you subscribe to this theory, then a single stereo mic may not be your best choice if you are recording 100' from the trains. (In any event, a pair of mics will give you more flexibility than one single-point stereo mic.)

If you're looking at a big investment, it might be worthwhile to rent a mic (or two or three) and try them, before making your final choice.

Scott Hiddelston · May 3rd, 2011, 11:36 AM

I was a fair distance away, Greg, probably 250-300 feet. I wanted to stay away to reduce the amount of panning I had to do, plus to try and reduce the "quiet-deafening-quiet" aspect of close-up recording. I feel in a way that I might have been too far away.
I understand what you are saying about stereo miking. Can I pick your brain once more and ask; if I bought another AT 875R rather than a stereo mic, how I should set them up for stereo? Should they be on tripods a set distance apart, or is their a way to mount them on the camera? Should they be pointed out at an angle or just mounted straight ahead?
Sorry if this is just regular info I should be researching on my own. If that's the case please let me know. I really appreciate all the help.

Jim Andrada · May 3rd, 2011, 12:46 PM

Hi Scott

One thought - get the mic's off the camera and closer to the "action". Best location for picture and best location for sound are almost never the same. Maybe more "quite/deafening/quiet would be better if the whole point of the exercise is the sound of the train. As long as you don't clip, you can bring the volume down to survivable levels in post.

Just a thought

Greg Miller · May 3rd, 2011, 04:52 PM

Scott, I agree with Jim. I'm not sure exactly what "experience" you are trying to capture and re-create, but 300 feet seems much too far to get clear sound. You can zoom in optically with a long focal length lens, but you can't do the same thing with a mic. High frequencies are attenuated more than low frequencies, by the atmosphere itself, and by surrounding foliage, etc. Something recorded at a distance of 300 feet will always sound relatively muddy, compared to something recorded at 25 or 50 feet.

(In fact, I played this for a friend without any explanation about what it is. My friend says, "It sounds like wind in a hollow tube." Even after being told it's a train, my friend says, "There's no sense of a train at all." That hadn'd occurred to me, since I know it's a train, but in reality the main thing you hear is the low frequency rumble of the engine, no sense of wheels, tracks, etc. That might, in fact, be what you really hear at 300 feet, but it doesn't especially jump out and say "train" on its own.)

If I were in your shoes, the first thing I'd do would be to find a good distance to capture the sound clearly and fairly realistically. Only after finding a good distance would I move on to stereo and experiment with mic position to get a good stereo image.

As far as the soft-loud-soft aspect of the audio, I wouldn't worry about it. Don't use AGC. Set the level of the recorder so that you don't clip with the loudest sounds (including when the whistle blows). Then, if you really think the level varies too much, you can subtly and gradually adjust level using some audio editing software.

Unless you think the trains sound realistic and have enough detail in these test recordings, try again at a closer distance. Maybe 100 feet for the next attempt. Or... do you like the present sound?

Scott Hiddelston · May 7th, 2011, 09:27 AM

Thanks Guys. I'll try and get some more video this week. The weather has gone back to miserable.

Battle Vaughan · May 7th, 2011, 10:14 AM

There is a distinctive sound to a train going by, if you are close enough---say, waiting at a crossing for the train to pass. The locomotive has a distinct low rumble from the diesel...assuming it's a diesel...and then each car, as it passes, creates a variation in the wind as the coupled sections between cars pass. And there is a regular clacking as, assuming you have non-welded rail or a rail junction at a crossing, as the wheels of each car pass over the intersection. It is a very rythmic sound but you have to be close enough to catch it....and then a deminishing whirr as the end of the train fades into the distance. This assumes the train passing you at some speed, of course....

Greg Miller · May 7th, 2011, 01:21 PM

Battle,

Did you listen to Scott's samples? If so, do you concur that a closer distance would probably sound more like what we're accustomed to when we think of the sound of a train?

(Of course, as I've suggested before, the perspective of the audio has to somewhat match the perspective of the video. If the video is a LS from a mile away, you don't want audio from 15 feet. But if the video is a telephoto shot from 300 feet, which looks like 50 feet, then audio from 300 feet will sound wrong, and audio from 50 feet might sound correct. )

March 29th, 2011, 07:17 AM	#16
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Re: Need Suggestions For Capturing Train Audio I would try the AT8022 stereo mic for about $359 online. It can be used either as balanced XLR or unbalanced mini-plug, as well as phantom or battery powered. I'd also add this shockmount for $50: http://www.bhphotovideo.com/c/product/554681-REG/Pearstone_DUSM_1_DUSM_1_Universal_Shockmount_for.html And add suitable furry wind protection. Stereo mics using one large grill tend to be very sensitive to wind noise.

March 29th, 2011, 11:58 AM	#17
Scott Hiddelston Regular Crew Join Date: Mar 2010 Location: Oak Harbor WA Posts: 66	Re: Need Suggestions For Capturing Train Audio Thanks everyone for some great advice here. Greg, I am ordering the Behringer ECM8000 today. I will take that along and try it as soon as it arrives. My nearest railroad is 30 miles away, and trains are a bit infrequent, which is why it's difficult for me to use one train to calibrate and then wait for more. Steve, those are fabulous audio and video tracks. In your youtube video, I'm really impressed with your capture from 5:39 through 7:03. the train can be heard clearly from approach, yet no distortion from the horn even up close. That is what I'm looking for, along with the laboring sound of the locomotives on a stiff climb. You guys have lit a fire under me now, and I am going to spend more time getting this right. Thanks !! I will report back with any results. While I wait for the omni mic to arrive I will stop using the limiter and try and get some kind of feel for where my settings should be using my AT 875R.

March 30th, 2011, 07:32 PM	#18
Greg Miller Trustee Join Date: Jan 2011 Location: Pennsylvania Posts: 1,786	Re: Need Suggestions For Capturing Train Audio Jay: It's interesting that you'd suggest the AT 8022. I have one of the two predecessor versions, the unbalanced AT822. I thought I'd try that as a minimalist approach to train recording. (Of course I'll have to check the headroom specs first, especially since it's powered by only 1.5 volts.) I will probably also take a pair of A/T small omnis, and maybe a pair of cardioids just for comparison. Scott: Let me know what you think of the ECM8000. I hope I haven't given you bad advice, but I have read some good things about that model, and it's certainly inexpensive enough. If you like the sound of one, do consider getting two; I really think stereo will help your "audio illusion." • Does anyone else have any experience with the ECM8000? Please post your findings! I, too, am about 30 miles from the main line (in Altoona) but I think the trains there are fairly frequent. I surely hope so because I'd like to try numerous takes when I go there for a day trip. I am still pondering the correct "perspective" for trains. On the one hand, I like the real feeling of power from the engines, which seems to be captured best at close distances. On the other hand, close distances create a little too much stereo spread for my taste... the train approaches fast, is close and loud for a second or two, then zooms into the distance. I would like the "fullness" to last a little longer. I realize some of these videos are made from perhaps 30' from the track, and the perspective I've heard is probably realistic for this distance. But I suspect it would be more pleasing to me if the train sounded close for a longer period of time. (Or do people get a "rush" from having the train zoom past so quickly?) Again, I think recording from the inside of a curve would help with this goal. (Sort of like the old visual trick of filming someone running through the woods, using a stationary camera on a pan head, having the actors run in a circle around the camera so the distance remains constant.) I will have to ponder this further. Maybe this thread will pick up as the weather gets warmer. Keep us posted!

March 30th, 2011, 11:16 PM	#19
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	Re: Need Suggestions For Capturing Train Audio Puttin' on my other hat as a volunteer machinist at the local railroad museum, let me suggest that locos are BIG---and they make different noises in different places. The 15 ft height suggested is great for detail on the diesel engine, which makes distinct noises from, for example, the valve assembly at about chest height if you're on the catwalk of the engine. And the horns, exhaust and such, are all pretty high up. On the other hand, the sounds of the trucks on the rails, the air brakes, various squeaks and rattles, are pretty much assoicated with the lower parts...the electric motors which drive the wheels are set low. I can see, if shooting close-up, a two-tier mike system would be good. Steam locos have lots of moving parts and different sounds from front to back as they pass, as well as from high to low on the loco and present a real challenge, I think. The farther you get from the loco, the more detail is lost and the more the sounds become sort of a heavy rumble at low speeds. At high speeds, at a distance you can get the doppler-shift sound as the train comes nearer then goes away, but lose a lot of the rail sounds.

April 29th, 2011, 09:28 PM	#20
Scott Hiddelston Regular Crew Join Date: Mar 2010 Location: Oak Harbor WA Posts: 66	Re: Need Suggestions For Capturing Train Audio Hi All, I have had a couple of weeks to try out the Behringer ECM8000, and I have to say that for $50 it does an admirable job. Compared to the AT875R I was using, the Behringer has a slightly more muffled sound, and high frequencies are not as crisp as the AT. But at 1/6th the price the Behringer is an excellent alternative. I found the Behringer to be less sensitive. Now I know the term "sensitivity" may mean something significant to you audio experts out there, but in my limited knowledge I mean it to be how sensitive the meter reads when sound appears. In this instance the AT is much more sensitive to changes in audio levels, and the audio meter dances up and down way more than the meter that's reading the Behringer. In some ways that would make the Behringer a better choice for me, but when I compare the two I can't let go of the crisp high frequencies out of the AT, especially when the train air compressors let a blast of air out. That's where the AT shines. But I have to say that neither of these mics, or for that matter ANY mic, is going to solve my problem. Because with my Panasonic HMC40, I can only guess at the best setting for any mic, and hope it doesn't get overloaded. Trying to turn down the little wheels on the XLR adapter would not only jolt the camera, but probably overload my brain functions and ruin the shot. Kinda like rubbing your tummy and patting your head. So is there any way I can buy some kind of machine/attachment/device that does record high quality sound, but also automatically adjusts gain to get good audio at a distance but compensate automatically as the train nears and the sound rises? Field mixer with auto gain perhaps? I understand that to the purists what I am looking for is not real true audio. But for my needs I want the sound of the locomotives to be dominant throughout the whole shot. From approach, to pass and to receding. Thanks for all your help. Scott

April 29th, 2011, 10:27 PM	#21
Greg Miller Trustee Join Date: Jan 2011 Location: Pennsylvania Posts: 1,786	Re: Need Suggestions For Capturing Train Audio Hi Scott, Glad to hear you're still "on track" with the project (pun intended). Very interesting observations. You hear a "brighter" sound with the AT, and that corresponds to the difference in frequency response. Look at the two graphs attached, showing output level (vertical scale) versus frequency (horizontal scale). Notice that the vertical scale on the two graphs are not the same. The AT875 has a peak of around +4dB, from around 4kHz to 7kHz, while the ECM8000 has a peak of around +2dB and a much smoother peak at that. So yes, the AT probably sounds brighter. Also, the AT has less output at the very low end, which shifts the frequency balance higher... again sounding a bit crisper. What you call "sensitivity" is not quite the usual definition. However, I understand what you're saying. I can only offer some guesses here. The AT is very directional so it is picking up different sounds as the train goes past; the Behringer is omni so the sound it picks up does not change as much when the train passes. Also, lower frequencies tend to be more constant in level (over a short time); higher frequencies bounce around more, and the AT is slightly more sensitive to high frequencies. All this could explain why you see the levels bouncing around more with the AT. Certainly you can buy a separate audio recorder, with good metering, switchable AGC, and switchable peak limiting. You will need one that supplies at least +11v phantom power to the mic, so that will elminate some of the less expensive recorders. Zoom makes a few which seem to be well regarded, the H4n (which even has a nice stereo pair of mics built in) is around $300; there are others upward from there. I would advise against using AGC, as it will try to make the level uniform. That will sound unrealistic, as the train is much quieter when it's 100 yards away than when it goes past 50 feet away. I have heard some bad train recordings where the whistle blows causing the AGC to lower the gain significantly. As a result, while the whistle is blowing the sound of he engine becomes extremely quiet; when the whistle stops you can hear the AGC quickly "turn up the level" of the engine. VERY unrealistic. I would suggest you set your level when the train is at its loudest... the nearest distance and with the whistle blowing. Adjust gain so you are recording at around -6dB. Then don't touch the gain control after that. You could also turn on peak limiting (if available) and that will protect you from clipping if the sound increases unexpectedly. (Peak limiting is quite different from AGC.) Perhaps some other folks will jump in here with recommendations for specific recorders. Meanwhile, if you do get an H4n, please do try recording in stereo... just use the integral mics... and see if that doesn't sound much more realistic than a mono recording does. Thanks for the update, and please keep us posted! Attached Thumbnails

May 2nd, 2011, 10:21 AM	#22
Scott Hiddelston Regular Crew Join Date: Mar 2010 Location: Oak Harbor WA Posts: 66	Re: Need Suggestions For Capturing Train Audio Thanks Greg, and all others who have contributed to this. I have looked at the Zoom H4n, which seems very nice. I also had a look at the Marantz 661, which is considerably more expensive. However I happened to see the AT 8022 that Jay recommended. Both the Zoom and the AT are comparably priced. So here I go with more questions..... Should I buy the AT 8022 or the Zoom? I have no need for an external recorder other than accompanying my video camera, and it would add the additional task of importing and syncing external audio, but would it be a better choice than just adding an AT 8022 to my camera and XLR adapter? Would one be better sounding than the other? I can try either (or both) and return if I don't like, but any advice would be appreciated. Thanks again for following along with this!!! I have to go out this morning but later I will post some audio files from train video I took Saturday.

May 3rd, 2011, 10:16 AM	#24
Greg Miller Trustee Join Date: Jan 2011 Location: Pennsylvania Posts: 1,786	Re: Need Suggestions For Capturing Train Audio I wasn't there, and I haven't listened to trains for many years, so it's hard for me to say which one is most realistic. All three recordings surprise me in that there's a lot less of the exciting "close detail" sound than I would have expected. But again, this is based on my hearing trains fairly close up, and decades ago. So this is more of a comment on my personal train memory, rather than on the accuracy of your recording. I notice the two single-mic recordings have a fair amount of level fluctuation... presumably caused by multiple engines going past, or by your panning the mics. The Sanyo recording has very constant level, so I would guess that recorder has a lot of internal AGC, which will tend to make the recording un-realistic. The response of the two single mics is as expected, based on the published curves. The Sanyo has more midrange and HF information (from about 500Hz to 6kHz), compared to the two real mics. I would guess its response curve is tailored to improve speech intelligibility. But again, this deviation from flat response will make for a less realistic recording. The Sanyo recording has very little stereo information... it is almost purely monaural. I don't really consider that to be a stereo recording. Either it was very far away from the train, or else the "stereo mics" are disappointing. I don't really have any info about your particular Sanyo, but many times internal "stereo mics" are omni capsules, and in that case they will not capture a decent stereo image if they're more than a few feet from the sound source. Out of curiosity, how far were the mics from the track? I have read some interesting theories about stereo recording. One such theory states that coincident cardioids (X-Y pattern) capture a good stereo image when fairly close to the source, but as distance increases, increased spacing between the mics is necessary to get a good stereo image. (This is analagous to the way really powerful binoculars have increased distance between the optics, to produce a good stereo visual image at really far distances.) If you subscribe to this theory, then a single stereo mic may not be your best choice if you are recording 100' from the trains. (In any event, a pair of mics will give you more flexibility than one single-point stereo mic.) If you're looking at a big investment, it might be worthwhile to rent a mic (or two or three) and try them, before making your final choice.

May 3rd, 2011, 11:36 AM	#25
Scott Hiddelston Regular Crew Join Date: Mar 2010 Location: Oak Harbor WA Posts: 66	Re: Need Suggestions For Capturing Train Audio I was a fair distance away, Greg, probably 250-300 feet. I wanted to stay away to reduce the amount of panning I had to do, plus to try and reduce the "quiet-deafening-quiet" aspect of close-up recording. I feel in a way that I might have been too far away. I understand what you are saying about stereo miking. Can I pick your brain once more and ask; if I bought another AT 875R rather than a stereo mic, how I should set them up for stereo? Should they be on tripods a set distance apart, or is their a way to mount them on the camera? Should they be pointed out at an angle or just mounted straight ahead? Sorry if this is just regular info I should be researching on my own. If that's the case please let me know. I really appreciate all the help.

May 3rd, 2011, 12:46 PM	#26
Jim Andrada Inner Circle Join Date: Feb 2007 Location: Tucson AZ Posts: 2,211	Re: Need Suggestions For Capturing Train Audio Hi Scott One thought - get the mic's off the camera and closer to the "action". Best location for picture and best location for sound are almost never the same. Maybe more "quite/deafening/quiet would be better if the whole point of the exercise is the sound of the train. As long as you don't clip, you can bring the volume down to survivable levels in post. Just a thought

May 3rd, 2011, 04:52 PM	#27
Greg Miller Trustee Join Date: Jan 2011 Location: Pennsylvania Posts: 1,786	Re: Need Suggestions For Capturing Train Audio Scott, I agree with Jim. I'm not sure exactly what "experience" you are trying to capture and re-create, but 300 feet seems much too far to get clear sound. You can zoom in optically with a long focal length lens, but you can't do the same thing with a mic. High frequencies are attenuated more than low frequencies, by the atmosphere itself, and by surrounding foliage, etc. Something recorded at a distance of 300 feet will always sound relatively muddy, compared to something recorded at 25 or 50 feet. (In fact, I played this for a friend without any explanation about what it is. My friend says, "It sounds like wind in a hollow tube." Even after being told it's a train, my friend says, "There's no sense of a train at all." That hadn'd occurred to me, since I know it's a train, but in reality the main thing you hear is the low frequency rumble of the engine, no sense of wheels, tracks, etc. That might, in fact, be what you really hear at 300 feet, but it doesn't especially jump out and say "train" on its own.) If I were in your shoes, the first thing I'd do would be to find a good distance to capture the sound clearly and fairly realistically. Only after finding a good distance would I move on to stereo and experiment with mic position to get a good stereo image. As far as the soft-loud-soft aspect of the audio, I wouldn't worry about it. Don't use AGC. Set the level of the recorder so that you don't clip with the loudest sounds (including when the whistle blows). Then, if you really think the level varies too much, you can subtly and gradually adjust level using some audio editing software. Unless you think the trains sound realistic and have enough detail in these test recordings, try again at a closer distance. Maybe 100 feet for the next attempt. Or... do you like the present sound?

May 7th, 2011, 09:27 AM	#28
Scott Hiddelston Regular Crew Join Date: Mar 2010 Location: Oak Harbor WA Posts: 66	Re: Need Suggestions For Capturing Train Audio Thanks Guys. I'll try and get some more video this week. The weather has gone back to miserable.

May 7th, 2011, 10:14 AM	#29
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	Re: Need Suggestions For Capturing Train Audio There is a distinctive sound to a train going by, if you are close enough---say, waiting at a crossing for the train to pass. The locomotive has a distinct low rumble from the diesel...assuming it's a diesel...and then each car, as it passes, creates a variation in the wind as the coupled sections between cars pass. And there is a regular clacking as, assuming you have non-welded rail or a rail junction at a crossing, as the wheels of each car pass over the intersection. It is a very rythmic sound but you have to be close enough to catch it....and then a deminishing whirr as the end of the train fades into the distance. This assumes the train passing you at some speed, of course....

May 7th, 2011, 01:21 PM	#30
Greg Miller Trustee Join Date: Jan 2011 Location: Pennsylvania Posts: 1,786	Re: Need Suggestions For Capturing Train Audio Battle, Did you listen to Scott's samples? If so, do you concur that a closer distance would probably sound more like what we're accustomed to when we think of the sound of a train? (Of course, as I've suggested before, the perspective of the audio has to somewhat match the perspective of the video. If the video is a LS from a mile away, you don't want audio from 15 feet. But if the video is a telephoto shot from 300 feet, which looks like 50 feet, then audio from 300 feet will sound wrong, and audio from 50 feet might sound correct. )