D112 & Shure sm58
I have been meaning to do some proper testing on car recording for quite some time and I finally had the chance today. As I’ve mentioned before we hire a car when we need one and this weekend we had a Hyundai Accent which was a perfect example of a stock standard small car, exactly what I wanted to test on. About a 5 minute drive from where we live is a large industrial area at Port Melbourne which on a Sunday morning is completely deserted and nice and quiet. The perfect location to get some clean recordings.
I started by strapping the R09 to one of the radiator tubes under the bonnet. A good length of Velcro strap meant that it was nice and secure and well away from any moving parts in the engine bay, while still being right in amongst the working parts of the engine. This resulted in a very good clean recording of 90% of the material captured. Because the bonnet is closed when driving there is almost zero wind to worry about in this location. I had one short section of recorded material that was effected by wind and only one level peak out of twenty minutes of recording. I made sure I tested the levels carefully before I started by revving the car up to 5000 rpm and ensuring the levels could cope. The good thing about this position is that it is so close to all the integral workings of the engine that pretty much all other sounds are irrelevant. This mic only captured very slight tyre/road noise and almost no noticeable noise from other traffic.
The second mic I placed was the D112 plugged into the H4N. I used the anchoring ring on the bottom of the car to slot the D112 through and then bind carefully with more Velcro strap. I was slightly worried about having a $300 mic attached to the bottom of the car, but after giving it a few good solid shakes I was fairly confident it wasn’t going to go anywhere. This mic captured some excellent material when the car wasn’t moving. Idling at different rpms were all clean samples with no peaking. (the D112 is designed to capture loud material) The sound from the exhaust had more bass and was throatier than the direct sound of the engine. When I started to drive though the D112 was far less effective. It has a pretty short range and because the anchor ring was about 50cm from the exhaust pipe once the car started moving and got up to speed the D112 was capturing more tyre/road noise than exhaust sound. I am going to need to find a way to mount the microphone closer to the exhaust. Admittedly the Hyundai is a fairly quiet car with very little exhaust sound, so maybe with a more sports orientated car having the mic 50cm away might not be too bad, but I would still prefer to mount it right next to the exhaust.
The other input for the H4N had the Shure sm58 attached to it, and the mic itself was mounted pointing out of the back of the boot to capture more general sound of the car as it moved. This was generally ok, but didn’t really capture anything that wasn’t covered elsewhere. Next time I will try this mic in different positions and see what I can capture. Lastly I turned on the H4 with the MKH60 attached in the boot of the car. Again this did capture some material but I think I could have made better use of a third recorder. I did later try the R09 inside the car as I was driving, and I think this would have been a better use for the H4 with maybe the NT4 mic attached. Overall I got some very good material, but I would still like to perform some more tests before I go off and record anything I cant get access to easily. I don’t want to waste an opportunity on a good sounding car while I am still sorting out the best approach to recording.
Once I found a nice quiet place to park I went through all the other sounds for this particular car. I have drawn up a list that I use for recording cars that allows me to check off each component as I record it so I don’t forget anything. This is a result of when I recorded all the old Holdens last year only to get home and discover I had completely forgotten to record any of their horns. I found the D112 was excellent at recording anything with an impact. Closing the bonnet, boot or doors all captured a good clean recording. The same items recorded through the MKH60 were far too noisy as the mic is so sensitive it captured road noise from a mile away and the sound of the wind through nearby grass. The D112’s short range effectively cut off everything but the sounds I needed. It was however far less useful for quieter sound like the washer and windscreen sounds. I have various microphones exactly for the purpose of using the best one for each job, however I am also aware that if I am capturing a series of sounds from one source I should be trying to get the sound as consistent as possible. The boot and bonnet were sampled nicely through the D112, but the door sound was too quiet. Using the MKH60 sample added wind noise and the different sound of the microphone. This is something I will need to do further tests on to see if I can come up with a good compromise.
When it came to the interior sounds I used the R09, but I found later that it was quite a shrill sound in the closed environment. I think I may have had the levels up a little too much, but overall the material is a little harsh. One thing I will say is that I need to be far more patient when I am recording something like an entire car. When cut up I have over 70 sounds to add to the library once I selected the good quality material, this is something I should not expect to achieve in an hour by hammering through every aspect of the car. Its certainly worth taking my time and capturing each aspect properly. I did spend over two hours doing the recordings, but I think I could have spent even another hour making sure I positioned the mics in more locations and doubled up on everything to improve the raw material I had to work from.
I plan on having at least one more full session with a standard car before I move on to anything more worthwhile, and just iron out the last few issues I have. I’m still not sure about the exhaust location microphone, but as I said a car with more grunt is going to produce a lot of sound from the exhaust anyway so it might be ok.
Stephan Schütze has been recording sounds for over ten years. This journal logs his thoughts and expereinces