Posted by: "Rob Danielson"
>>>>> Thanks also for the breakdown on the SASS
>>>>> construction on your website! Rob D.
I had a few people ask, so photographed the process of making one last
year and put the pages up. There have been a few people who at least
started to make their own. I did not hear back from them after I
answered their questions on details so I don't know if they finished. I
hope they are happy.
As I noted on those pages, it's just one way the construction could be
approached. A way that fit the tools I have and my design ideas. A pro
machinist might laugh at how I do some of it. I was building two more
SASS today, hoping to ship them off early next week, I'm getting awfully
practiced at it.
If you are considering making your own, ebay is a good place to find
reasonable prices on the delrin. I use it because it machines so
beautifully and is very durable. The ABS sheet also came off ebay.
> Hi Walt--
> When Eric measures and prints "8dB(A)" self noise, I tend believe
him. He has an pseudo-anechoic chamber and quality test gear. What
character of noise The AT3032 produces at that level, we'll know more
and more about over time.
I was pointing out this is a single mic sample. The two mics I had
access to were not as quiet as the MKH-20's I have, at least to my own
hearing. I did a lot of wandering around listening before I got them
mounted in the SASS. Even afterward I did some listening with a MKH-20
on one side, a AT3032 on the other. The MKH-20 is rated 10dBA self
noise, and I judged them slightly more noisy than the MKH-20. What I'm
wondering is just how consistent the results of Eric's test are across
all examples of this mic, not that he measured that. It is brought into
question as AT rates the mics at 16dBA, not 8dBA and they are the
designers and manufacturers. I'm sure if they are consistent at 8dBA
they would have that splashed all over as it's a good selling point.
Have we had anything out of AT as to how there could be such a
difference? Is the low noise consistent across all examples of AT3032's,
if not what is the range? These are questions to be sorted out.
I'm not really the one to sort it out, I'm not about to toss the mics
I'm using and go to them. I do get lots of inquiry's about the SASS and
the big stumbling block for most is the buy in of the two MKH-20's. So,
when I had a opportunity to try a pair the first thing I was interested
in was seeing if they would work in the SASS in a reasonable manner. I
provided the samples in case anyone else was interested. I've provided
my impressions based on that short usage, for what it's worth. Note it
was free comments.
As Bernie mentioned, the MKH are very, very consistent. A substitute
needs to be consistent too. For stereo you are working two mics that
need to be closely matched. It's easier if you can hunt for them
anywhere and don't have to go into the trouble of getting "matched pairs"
> I do recall Klas first mentioning the height advantages back in 2001.
Not long afterwards, though, you built your first 16' rig.
Yes, it was hearing his mention, coupled with my experience measuring
sound in a forest that sent me off to try a high tripod I'd recently
gotten off Ebay for just such use. Hearing Klas brought some thoughts I
had to the surface and got me moving on trying it out.
> I re-read Crown's SASS material and looked at Bruce Bartlett's
comparisons again
> http://www.tape.com/Bartlett_Articles/stereo_microphone_techniques.html
> in which he attributes the SASS ("Baffled OmniPairs") these features:
>
>
>>> *It uses two omnidirectional mics a few inches apart, separated by
a baffle.
>>>
>>> *Level, time, and spectral differences between channels produce the
stereo effect.
>>>
>>> *Images are sharp.
>>>
>>> *Stereo spread tends to be accurate.
>>>
>>> *Low-frequency response is excellent.
>
>
>
> "Level, time, and spectral differences" are especially impressive.
The SASS discriminates timing difference below 700Hz (much like our
ears) and level differences in the higher frequencies. Interestingly,
the SASS, the Jeckiln variations people are experimenting with and Curt
Olson's "head-spaced parallel barrier array"
http://www.trackseventeen.com/images/mic_arrays/3032_parallel.html
> all seem to fall within Bartlett's "Baffled Omni Pairs" category
with these benefits. Rob D.
He in fact says they all fall in that category. Well, except he did not
mention Curt's experiments ;-)
His statements are a fairly general summary, and in a general way these
mic setups do resemble each other. But they also differ when you get
into specifics. I do not think he was specifically singling out the
SASS. My experience with studio recordists is that few are even aware of
the SASS, and if so it's the original unmodified SASS. I've run into one
concert recordist who was aware of the discontinued version of the SASS
that mounted DPA mics (the one I beat out on the MKH-20 auction). It was
that version that Lang modified to make his first SASS/MKH-20. I think
it's safe to say that the SASS/MKH-20 is almost entirely being used for
nature recording. Only a few I've built for planned any music recording
with it. I think it was the only place Bartlett could stick it. I'm not
sure the foam baffle is it's only defining characteristic. I more like
to define it as a head spaced boundary pair. The foam just represents
what's between our ears ;-)
Note that Bartlett's statements were about recording within the confines
of a indoor space. While generally applicable to outdoor recording there
are differences that are clearly only partially understood. I've read
quite a fair portion of the material available on stereo and virtually
all start with a confined space to record in and design their mic setup
to that. There's plenty of new discovery waiting out there.
Note the SASS/MKH-110 appears to continue the low frequency
discrimination down even maybe into the infrasound.
Note I recommend the modified SASS for nature recording for more than
just it's audio characteristics. It's a compact and lightweight stereo
mic setup, easily transported in the outdoors. It's fairly easy to wind
protect and does not have a lot of problem with handling noise. There
are other setups that have these characteristics as well. They are
important for a day to day mic in the field.
For me it anchors the wide end of my various mics in terms of the field
it records well.
Walt
"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg
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