Problem recording Steam Locomotives

[73096]

I've been recording with MD for just over a year now. After much trial and error I'm fairly satisfied with the results I get now, although one aspect still causes problems. If a locomotive sounds its whistle close to my position (which is normally close to the track) I sometimes get the distortion you can hear on the attached recording here. 6024croftonforum_1.mp3 Everything sounds okay until the loco passes and whistles. I'd like to know the best way to counter this effect as I don't know which part of my set up is causing the problem.

I'm using an MZ-R35 with a Sony ECM-MS907 mic and a 20dB preamp from micbooster.com. I set a manual level turned way down with mic sensitivity set "low". If I turned the level down further the recording would probably be too quiet but would this solve the problem? Do I need a new MD where I could adjust the level during the recording? Perhaps a new mic (thinking of AT 822)? As I'm fairly new to this any advice would be very much appreciated.

Edited December 30, 2006 by 73096

[AllanH]

I've been recording with MD for just over a year now. After much trial and error I'm fairly satisfied with the results I get now, although one aspect still causes problems. If a locomotive sounds its whistle close to my position (which is normally close to the track) I sometimes get the distortion you can hear on the attached recording here. Everything sounds okay until the loco passes and whistles. I'd like to know the best way to counter this effect as I don't know which part of my set up is causing the problem.

I'm using an MZ-R35 with a Sony ECM-MS907 mic and a 20dB preamp from micbooster.com. I set a manual level turned way down with mic sensitivity set "low". If I turned the level down further the recording would probably be too quiet but would this solve the problem? Do I need a new MD where I could adjust the level during the recording? Perhaps a new mic (thinking of AT 822)? As I'm fairly new to this any advice would be very much appreciated.

Hello 73096

Welcome to the wonderful world of railway sound recording. I guess you're in the UK?

Listening to your clip - I think you are too close to the line, and too close to the Whistle Board.

I'd get further back from the line - this will allow the sound level to rise and fall and more smoothly as the train passes.

Locos dont usually whistle at random - only where they are advised to do so. So it may be worth scouting the line for the location of Whistlle Boards (W in a circle) and then making sure you don't get too close. Of course this is easier on a preserved line than on the main line, where your recording was made.

Its always tricky with railway recordings - you have to set the recording level when the 'subject' isn't present and just hope you get it right. There are no second chances with a main line express, and distortion from the whistle also depends on the type of loco - I doubt a Gresley chime or a Stanier hooter would have distorted on your recording clip.

I'd experiment with positioning relative to the lineside before buying new equipment. ( I often record from 400 yds back). A good preserved line would give you lots of opportunity to make practice recordings - SVR or NYMR on a Gala Weekend perhaps? A new mic probably won't help. A HiMD unit where you can manually set the recording level would make recording easier, but wouldn't have prevented distortion from the whistle in this case - the input signal to the recorder is just too high. Its possible that the Micbooster might be putting out such a high signal that the MD preamps are being overloaded even at a low record level. Have you tried without the Micbooster?

Good luck - and come back if you want to discuss things further.

AllanH

[boojum]

I do not know if I know what I am talking about, but - if it is low gain would not normalizing the recording bring it up to as loud as it can get without clipping? Once it has clipped it is ruined but raising the volume after works. And, in digital the background noise is minimal, too.

Edited January 2, 2007 by boojum

[73096]

Thanks for your reply AllanH

Yes, I'm in the UK. In the cramped confines of the Kennet and Avon Canal with "King" 6024 in this case. I can see that I need to take more account of the recording location. Just as important though, as you say, would be the actual locomotive. I've been virtually on top of a Gresley A4 whistle with no distortion. I'm usually trying to photograph the loco at the same time, so there is often a bit of compromise when thinking about locations.

I did start off recording without the micbooster but the recordings seemed to have a lot of hiss on the quieter sections. The micbooster completely solved that and I was much happier with the results. I don't do alot of post processing with the recordings, just edits and fades really. Are there any techniques that would reduce the hissy effects in the recording or editing stage?

I'm pleased that you think the equipment I'm using is generally okay. I do need some more wind protection for the MS907 and then perhaps some practice at my local preserved line the "Mid Hants", before the mainline season really gets going again.

boojum, I will give that a try on some recordings. As you say, once the recording is clipped/distorted there's not much you can do.

Thanks again for your comments, all very interesting, I'll come back when I've had some more practice.

[A440]

Are there any techniques that would reduce the hissy effects in the recording or editing stage?

An editing program like good old free Audacity

http://audacity.sourceforge.net/download/windows

has a few tricks under Effects that you might try on your recordings.

One is Noise Removal: You give it a sample of the hiss alone, which you probably have somewhere on the recording, and then it subtracts those frequencies when the reduction is applied.

Another is just filtering. Hiss is high frequencies, so if you add a Low Pass Filter--it only lets through frequencies up to a certain cutoff point that you set, maybe around 7000 Hz--then your recording might sound better. It's way down the list, so scroll for it.

Neither is an automatic cure-all. Noise removal may remove so much that the recording sounds unnatural--try the middle amount, not the maximum. Low pass filtering may make your recording sound slightly dull or muffled because the higher frequencies give the sound some crispness. (Try various cutoff frequencies.) But both are worth some experiments, as long as you save your original recordings.

If you're new to Audacity, it has one main oddity. It does all its editing in its own format, .aup. So when you edit an .mp3 or .wav file, it turns it into .aup, works it over, and then "Save project" or "Save changes" means it keeps the edited version as an .aup file. To save your edited version as an .mp3, you have to Export as .mp3 (also under File). I don't see why they don't call it "Save as .mp3" but hey, it's great free software anyway.

Since your preamp reduced your hiss, the hiss was probably coming from the built-in mic preamp in your MD recorder--which is pretty good, but obviously so tiny that compromises must be made. It seems that the Micbooster is giving you a cleaner signal, which is all to the good. I assume you're running the booster through Line-in?

AllanH, what recording setup do you use?

Boojum, the problem with normalizing is that it raises noise along with signal. So the ideal is always to get the strongest signal possible without distortion--playing close to the edge but not over it.

Edited January 3, 2007 by A440

[boojum]

Boojum, the problem with normalizing is that it raises noise along with signal. So the ideal is always to get the strongest signal possible without distortion--playing close to the edge but not over it.

A440 - I understand that the noise floor is also raised but with digital it is way less a problem that with analog(ue) was. No tape hiss and so on. It is worth a try.

The pro at this is the guy who started Mobile Fidelity. He was the consummate train recorder who was trackside with his mobile gear often, and that was the source of the name, Mobile Fidelity. I do not know if he published any info on his tricks. I do know he used a huge reel-to-reel tape recorder.

[73096]

An editing program like good old free Audacity

A440 - Thanks for the mini tutorial for Audacity, I'll certainly give that a try. I'm actually using mic-in rather than line-in. The line-in option looks to be for particularly loud sources. For recording trains lineside there can be very quiet patches during the recording when the train is approaching from a distance, would line-in be an option in those conditions? I could give the line-in a try for recording "on-board" which obviously gives a much louder source.

I too would be quite interested in your set up AllanH.

boojum - hadn't heard of Mobile Fidelity before, I'm sure learning alot on this forum!

[AllanH]

Hi All

73069 - from your note about the micbooster I guess this is overcoming the poor signal to noise ratio of the preamp on an older MD machine. As you're not having the distorion problem with a Gresley chime, I'd put you rproblems down to the whistle on the particular loco. I always have trouble on the NYMR with high pitched pure tone whistles - such as SR 825 - when I'm too close. I now have map marked up with whistle locations and I make sure I'm a respectable distance away.

You could try removing the whistle distortion with declipping software (there's a tool in Magix Audiostudio) - some times it works, sometimes the result just sounds odd. Same software (ond others) has hiss removal tools but I've never had a lot of joy with them: too little processing and the difference is hardly noticable; too much processing can give some very odd results. But it can't hurt to try.

Windscreens are easy to make. Look at [http://www.uwm.edu/~type/audio-reports/DIY_NT4_3inchPVC_ShockZep/DIY_NT4_3inchPVC_ShockZep.html] for the general idea. There's lots of good ideas on these pages.Drain tube, rubber bands and some furry fabric generally do the trick.

About my equipment:

In the 1980s I used a Walkman Pro cassette machine + a Sony ECM929LT with reasonable resutls. Even after tape to tape editing the results were OK to listen to. I produced cassettes for sale with this set up. You should be able to do much the same with your current set up. I know one current recordist who is using MD + ECM959 very succesfully on commercially available recordings.

I used an MZR-37 + 909 combination at LeMans in 2000 to record some of the 24 hour race, with very nice results.

Over the last 2 years, returning to railways, I've used HiMD (NH900 etc) with a variety of mics:

- ECM 959, ECM999 (which has better bass but much the same hiss level as the 959 or 909. Not surprising as they are all Sony electrets).

- Rode NT4 (my mic of choice for an easy portable outfit, but needs a mod to the mic cable to minimise the hiss level and a good windshield). I've use this for motorsport too.

- pair of Rode NT1As - the no compromise king of budget-priced quiet mics, but needs a bespoke windshield and a 48V phantom power supply. Bulky but worth the trouble in my view.

- pair of AT3032s spaced omnis also gives nice results, but again a phantom supply is needed.

Incidentally, you can't use a micbooster through line input - it takes its powered by the Plug-In Power supply from the mic socket.

All the best

AllanH