Rob Danielson wrote:
> Thanks Curt- I was experimenting with omnis on two, spaced, parallel =
> boundaries last week and I was consistently aware of a mid range lift =
> and improved lateral spatial definition.
Yup. I've found this also. I'm guessing there's some "boundary effect"
going on there. The spacial definition is absolutely the most pleasant
surprise about this approach. And as a bonus, it seems to hold up
relatively well on both headphones and loudspeakers -- at least on my
system.
> The 3032's are inherently "huskier" so I'm not confident of my ability =
> to sort this difference out when comparing the arrays.
I like your word "huskier." That's a great way to put it! But one
correction: the ORTF file was recorded with the cardioid AT-3031s. One
nice surprise about the 3031s is that they seem to be far less prone to =
handling noise than many other cardioids I've tested.
> I also heard considerable 3K+ Hz "bite" in the 183's which may stem
> from the 183 capsules and/or perhaps the higher percentage of direct
> vs reflected sound with the boundary effect.
My observations also. And I think you're right that it's a combination
of the upper-mid lift of the 183s plus some boundary effect. For Walt
and others, please note that I don't consider this to be a "boundary"
rig, but rather a "barrier" rig. But because the mics lie so close to
the barrier, there's definitely some boundary effect that comes into
play.
Incidentally, I've been surprised to discover from my tinkering that
the barriers in a rig like this don't have to be very large to produce
a nice image. I'd be especially interested in hearing any contrary
opinions about that.
> At any rate, with these recordings, I prefer both the image and the
> tonal balance of your rig/183's.
If I had two phantom power supplies, I would have run the test with the =
3031 ORTF rig and the 3032 parallel barrier rig, also shown in the
photo. That would have been a much better test, as both are a bit
"huskier." But alas...
> I'm not sure the volume is matched close enough for extreme scrutiny, =
> but here are the sonograms I got from the fireworks flurry:
>
> https://pantherfile.uwm.edu/type/public/temporary/
> FireworksTest_Sonograms.gif
That's also an interesting point. Because of the tonal differences
between the 3031s and the 183s, and also, I'm guessing, because the
imaging is so very different, it was harder than I expected to get a
decent level match across the whole sample.
Thanks for your feedback, Rob!
Curt Olson
>
> At 10:54 PM -0500 6/22/06, Curt Olson wrote:
>> Rob Danielson wrote:
>>
>>> With Curt Olson's double boundary rig, he places omnis,
>>> front-facing, next to two, hard surfaced, wood boundaries. The two
>>> boundaries are separated about 4" so the capsules are around 6-7".
>>> I'll dig-up Curt's photos.
>>
>> Here they are, Rob...
>>
>> http://www.trackseventeen.com/images/mic_arrays/3032_183.html
>>
>> A couple weeks ago the little suburb where I live held its annual
>> community festival, which included a local country-western band and
>> some fireworks at the city park about a half mile from my home. For
>> kicks, I set up two mic arrays in the yard to make some comparisons. =
>> One was a modified ORTF-type pair of AT-3031s (capsules at 90 degrees =
>> and 5.5 inches apart). The other was a pair of Shure WL-183s mounted =
>> approximately as shown in the photos linked above.
>>
>> Here are a couple short excerpts. The first is a 1:34 segment of
>> evening neighborhood buzz, with the country band playing in the
>> distance. First, the 3031s, then the same segment recorded with the
>> 183 rig. No processing except for some rough level matching...
>>
>> 128 kbps MP3 (2.8 MB):
>>
>> http://www.trackseventeen.com/media/tsp/060611a-3031_183.mp3
>>
>> 16/44.1 WAV (31.6 MB):
>>
>> http://www.trackseventeen.com/media/tsp/060611a-3031_183.wav
>>
>> The second clip is a 1:06 segment from the fireworks. Again, the 3031s
>> first, followed by the 183s, with 6 seconds of blank between...
>>
>> 128 kbps MP3 (2.1 MB):
>>
>> http://www.trackseventeen.com/media/tsp/060611b-3031_183.mp3
>>
>> 16/44.1 WAV (23.2 MB):
>>
>> http://www.trackseventeen.com/media/tsp/060611b-3031_183.wav
>>
>> I hear some interesting differences between the two arrays.
>>
>> I agree with Walt that there's no way we can come up with definitive =
>> recommendations here. But I always find it helpful to hear other
>> people's recordings, especially when it's accompanied by info about
>> the mics and patterns used.
>>
>> Curt Olson
|