L1® Traditional Music System

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Fountain Pen

This article is an editorial and expresses the opinion and experience of the author. Please post comments in the discussion page.
Thank you.

Ken-at-Bose posted this in the Bose® Pro Portable PA Community[1] October 1, 2005
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Hi Folks,

Yesterday, as planned, we did another round of testing of our Traditional Music System.

We had 4/5 members of the wonderful bluegrass group Bow Junction (http://www.bowjunction.com) here at our Live Music Listening Room at the Bose Reservoir Building. This is a nightclub/small-auditorium sized performance space we use as our live music laboratory.

Bow Junction purchased three Cylindrical Radiator® speakers more than a year ago now and use them in a variety of situations. Bow Junction (minus upright bass player who was ill):

Russ Aufertin - Guitar
Kathy Barnes - Fiddle
Lina Magoon - Mandolin
Pete Ocom - Banjo

We were also joined by banjo player extrordinaire Rich Stillman, and guitar great Geoff Bartley. Rich has been helping us learn about the needs of traditional music players. Geoff, who runs a famous traditional music weekly jam here in the Boston area, is also Tom Paxton's playing mate, and designed the new Tom Paxton Signature Model Guitar. (Tom Paxton will receive the highest honor from The Folk Alliance in January -- The Lifetime Achievement Award -- HOORAY TOM.)

Our goal was to explore microphone spacing, player comfort, and microphone type in our work over the course of about three hours. Steve, Brendan, and I, all of the Bose Live Music Technology Group were there to help and listen.

In the course of the next several posts, I'll describe in pictures and words what we found from my perspective. I'm sure that some of the other participants will add their voices to this discussion on the message boards, and as always, we welcome yours.

Here's the Traditional Music System setup with the notes added.

Here's a link to the Sketch in case you want to review it, edit it, print it, or share it with others.

-- click image to make changes to the live version --
L1® Model I/Classic
Orange numbers are Systems and Inputs using those Systems.
Blue ringed numbers are Channel connections to/from the Classic and Model I Systems.
Green numbers are for general notes about the Sketch and connections to non-Bose gear.

Quoting Ken-at-Bose from The Sketcher

Spacing of mics should be about 30 inches (75 cm).

Microphones successfully tested are: Shure KSM44’s on cardioid pattern (there is good reason to believe they will also work well on figure eight pattern but this has notbeen tested); Audio Technica AT4033, and AKG 3000-B. All can be purchased at good prices at Musician's Friend.

Microphones should be "toed in" by about 10-15 degrees: in other words,should be turned so that their diaphram is pointed a little in towards the center rather than straight back.

Cylindrical Radiator(r) speakers can be "toed in" too. Point them in toward the center of the audience 10-15 degrees. This will provide a little more foldback to the players so they can hear their mix a little.

There is reason to feel that the upright bass might be better off plugged directly (via pickup) into system 1 or 2 rather than go through the mics. The reason is that it is often difficult for the bass to be "choreographed" well enough relative to the mics given its size. This has not been tested and so remains a question mark.

Warming Up

Here's a picture of Bow Junction at the beginning of the test, just getting warmed up.

Amplification: A Necessary Evil

Recall that in traditional music, amplification is often viewed as an evil necessity. Many players would prefer it if they could magically just play unamplified and somehow have their audience hear them clearly.

The rapid falloff of sound of their instruments (the same as for conventional speakers) prevents this, however. If they just play "au natural" it may be glorious for the players, but it's not for the audience -- it's not loud enough (except perhaps the front row.)

[Here's Geoff Bartley explaining a point to the musicians. Geoff filled in on Bass: more on how we amplified that in a moment.]

Pickups anyone

One solution of course is to put a pickup on every instrument and give a microphone for each vocalist. This certainly works spectacularly with the Personalized Amplification System(tm) approach, but it tears at the fabric of traditional playing by pulling the players apart in space and putting them into more of a Rock 'n Roll format instead of the tight knot they love. Also, for many traditional players, putting electronics into their instrumentst is sacrilege.

A popular approach emerged for amplifying traditional and bluegrass bands where they all play into a single large-format condensor microphone which is then fed to the PA. The players move into the microphone when it's their turn to solo or sing, creating a new kind of choreography demanded by the amplification system. This approach goes a long way toward making the players happy and getting enough sound level into the audience. But there are some weaknesses. One is that the players don't hear the PA speakers and therefore don't hear the effect of their choreography: they're guessing at how their mix sounds. Another is that what's sent to the PA is a mono signal and in the audience, you hear all the instruments come from the PA speaker to which you're nearest.

Here's Steve of the Live Music Technology Group (second from left) with Brendan (left) and Rich Stillman, talking to Kathy Barnes about our new setup (described below)>

Condenser Mics

If you try to set up one of these large "group condensers" with the Cylindrical Radiator® speaker placed behind the performers, you can't get much gain because the players just can't get close enough to the mic and if even if they could the difference in volume from their normal position when not soloing would be musically far too great and would sound severe and unnatural.

The brain wave for a different application of the Cylindrical Radiator speaker came on April 2nd of this year in an earlier test. You can read all about this discovery in a very interesting thread on this Message Board by clicking here,

The idea was to push the Cylindrical Radiator speaker downstage to the lip, where the extraordinarily wide pattern of the speaker would both cover the whole audience and wrap some sound back to the performers on stage.

Moreover, if TWO large diaphram mics were used instead of one, spaced a few feet apart, a left one feeding a speaker on the left (only) and the right one feeding only a speaker on the right, then the audience would enjoy a glorious spatiality not present in typical bluegrass amplification setups. This basic approach was tried in April and produced unbelievably satisfying results. The audience heard the band at very good levels. But with the extraordinary pattern of the Cylindrical Radiator speaker, even on the extreme right of the audience they clearly heard the speaker on the left, and vice versa, something no conventional speaker could do.

Here's a picture of the setup in the test yesterday, showing the two speakers left and right and the two Shure KSM44 mics on stage. Note that the mics were switched to their cardioid pattern, with the main lobe pointed towards the players and the null of the pattern pointed toward the audience.

The Band Loved It

The band of course totally loves this. They get to play "in the nude", tightly knit into a street corner ensemble, using their standard 'microphone choreography' to accentuate solos. They hear enough wrap around from the speakers to get a good sense of the effect of their choreography on the mix without getting so much amplified sound that it takes away from their own natural acoustic ensemble sound.

Yesterday, one of the things Brendan, Steve, and Rich set out to determine was the effect of mic spacing on the audience sound.

Here's a picture showing Brendan and Steve poised to change mic spacing during a performance, with Rich and Ken (mostly Rich) out in the audience judging changes.

Tweaking the Mics: Focus or Spatial

What we found is that if the mics are too close, you get a very intense feeling of focus in the music, but you lose quite a bit of spatiality.

If you go too wide (we tried up to five or so feet) you got glorious spatiality but the soloist in the center got a little lost.

We ended up with a compromise of three feet (Steve may make a slight correction to this later: I did not see the final tape measurement). This gave the technicolor spatiality and the intensity for the soloist that we liked. It was a very satisfying compromise of the two extremes.

Note that the mic stand in the center without a mic on it became the players' target for their choreography. When it was their turn to be accentuated, they moved in to the tip of the middle mic stand, not into one or the other of the mics. In a real performance, this middle stand would be removed, or a far more visually inobtrusive target would be used.

For this test, we had Geoff's bass plugged into a third system located just behind him. If we had an upright bass as is the case with Bow Junction, we would have plugged him into one of the two systems downstage. There's still a little work to do once we get down to Nashville to make sure the upright bass sounds good.

Here's the band kickin' out a song towards the end of the testing. Virtuouso Rich Stillman filled in on banjo so that Pete could come out and listen from the audience.

A Beautiful Day of Testing

Toward the end of the test we tried switching to AKG C-3000 mics (also large-diaphram condensers, owned by the band) and were jolted with another surprise. Suddenly the setup was able to play much louder, about 6-8 dB, without coloration or feedback. This was a pleasant surprise. Later, I'll investigate the polar patterns of the Shure vs. AKG designs to see if I can make sense of this large difference. If the AKGs have a tighter pattern, that could explain it.

It was a beautiful day of music and testing. The band was wonderful and very helpful. They played great. Rich and Geoff were great as experts in this field. Here's a group picture of the test group at the end of the session.

We all look forward to answering your questions and thinking about your comments. I believe the band is already reading this Message Board and we're likely to hear from them.

We would recommend this setup without hesitation for traditional groups wanting to play in a natural way to audiences up to several hundred. We believe it is a setup with an unprecedented suite of benefits for both players and audiences.

The general discussion that this generated continues here:

Traditional Music System Test Results in the Bose® Pro Portable PA Community

The follow-up to this article is here:

IBMA - International Bluegrass Musicians Association - October 26 2005