Recording Exhaust Notes...

[365 GT 2+2]

Anyone audiophiles out there with some advice as to how best to record the sounds from our exhausts? I don't want to break the bank, but I also want gear that will correctly capture the exhaust note with the goal of recording my new Ansa exhaust system in my Queen along with a few other Queens - including Dick's who has a new stainless Stebro system. Thoughts?

[TOMKIZER]

According to Tom Yang's write up in the "Who Am I?" heading in the left column of his home page, he writes:

"When I bought my Ferrari, I was an audio engineer in New York City, working for a television show called "Late Show with David Letterman."

You couldn't be in a better place.

Tom Kizer

[365 GT 2+2]

Yeah - I have run it by Tom but he is up to his ears with cars and stuff so also wanted to see if anyone else has any thoughts.

[tyang]

I feel the best way to record something complex is to first try something simple. Over thinking the process may not necessarily get you better results. If you have problems with the easy method, then make small changes until you reach a solution.

Tom B. wants to record the sound of his car, but when I asked if this was the sound from inside or outside the car. Unfortunately, he said outside, which makes things a little harder. Recording from outside from a point on the car will have wind noise to contend with, and sound from a fixed position as the car passes will be short, and probably not what he wants.

My simple solution is to record the car from inside the car with a camcorder type recording device. I know Sony consumer level microphones offers some real good sound for what you pay for, and their AGC (automatic gain control) circuits work fine without having to mess with the settings. Most digital video cameras have digital outs on them to transfer directly to your computer, and you can easily export the stereo audio tracks to WAV, AIFF. or MP3.

Also a note on consistency, If you're going to do comparisons, you must keep acoustic factors the same. Placement of the car is just as important, making notes on surfaces, ie. walls, trees, open fields. Keep the recording device the same distance from each car. SPL (Sound Pressure Levels) fall off logarithmically with distance. Also be aware how far you are away from the source of the noise. As much as I like the sound of Sony Mics (for what you pay for), they can't handle high SPL, so overloading them by putting them too close to the source will distort the recording. Anything louder than a shout may be too much for these mics. Move the recording device back if it's too loud.

If you still want to buy some gear, there are some neat Stereo Hard Chip recorders I saw at B&H in NYC a couple months back. They can take external microphones or use their built in mics for recording, but again, it's going to take some knowledge to make good recordings.

I did some recordings a couple years ago of exhaust noises:
http://www.tomyang.net/cars/ferrari473.htm
They were very low tech, much like the process I described above. If I were to do it any better, I would have to break out about $2K worth of gear!

In audio and in many other fields there is a rule of KISS...which I subscribe to. The first three words are Keep It Simple, and the last is what I am, stupid. It worked for me!

Tom

[Yale]

I have hesitated answering this question because I knew if I started writing it would end up like the following:

I don't think you will actually be able to have a "reference" recording sound wise actually. I run a small record label and have produced a bunch of albums as well as recording Indian Disco Wedding Bands, string quartets, gamelans and whatever, in the field, so to speak. An exhaust system is not music, (though it may be musical), and as such every part of the frequency range has a greater impact on what the listener 'feels' they are hearing. Which means that every sound system you play these exhaust recordings back on will be as much of a determining factor sound wise as any other part of the recording chain; where you stand, where the car is located, what kind of mic you use, etc. Probably the least important aspect of all this is what brand of digital machine you record it on.

Are you planing on having people listen on their 1" computer speakers, their home theaters, or maybe their car stereos? As you can see it is somewhat of a chasing your tail excercise when you use the word "reference."

Here is a list of digital field recorders sold by B&H Camera:
http://www.bhphotovideo.com/bnh/control ... bmit+Query

Some record to flash drives, some record to CD's some have an internal hard drive, some have built in mics, most have only so, so mic pre amps. (There are people that tweek some of this gear to make it higher quality). This is probably more then you want to know because there is no answer. You will be able to make a crappy recording with anything here and you will also be able to make a recording that satisfies you with anything here. Pick the media you want to record to, buy something with a built in mic, try that. It might have too much wind noise or just other-then-exhaust noise, so then get a one point stereo mic with with wind filter. If your still not happy get some great mic preamps. Still not happening? Build and anechoic chamber to put the car in....ok you get the idea.

Best,

Yale

[Yale]

Hah! I started writing the below then Tom called me. We got off the phone and I then finished and posted. Now I see Tom wrote a very similar response at about the same time.

[365 GT 2+2]

See, that's what I love about this forum: Ask and ye shall receive. Thanks for the ideas and for the links. You guys have given me some ideas. I'll keep you guys posted...Thank you