DPA Microphone BLM6000 User's Manual

DPA Microphones A/S

Gydevang 42-44

DK-3450 Alleroed, Denmark

Tel: [phone]

Fax: [phone]

[e-mail]

www.dpamicrophones.com

DPI-BLM6000

USER’S MANUAL

Boundary Layer Mount

Type BLM6000

USER’S MANUAL

Freq.

Frequency response

Sens.

20
15
10

5
0

-5

20

-15

-20
250 500 1K 2K 5K 10K 20K

Boundary Layer Mount

Type BLM6000

The BLM6000 is an accessory that will
extend the use of your DPA miniature
microphones i.e. DPA 4060, 4061, 4062,
and 4063.

By placing a microphone close to a reflec­tive boundary, you will benefit from the
special characteristics of the sound field
found here: a 6 dB gain of direct sound and
only 3 dB gain of the diffuse sound. This
means that the sound picked up has both
greater clarity and intelligibility compared to
the sound picked up in "free air".

Mounting the microphone

It is very important to mount the micro­phone correctly! If not the sound may suffer
from colouration.

The smoothest frequency response is
achieved with the diaphragm perpendicular
to the reflecting boundary. In order to iden­tify the position of the membrane you may

BLM6000

BLM6000, rear view

have to temporarily remove the microphone
grid (see picture). When you mount the
microphone in the BLM, be sure that the
mesh is completely hidden, so there are no
openings, as they will affect the sound.

Please note: The microphones must be
mounted with the short grid (soft boost
grid). The long grid will not fit into the disc.

Using the Boundary Layer Mount

When mounted in the BLM6000 you can
put the microphone on all surfaces that
reflect sound i.e. tables, lecterns, etc. Even
floors, walls and ceilings are very ef fective
as boundaries when the BLM6000 is
attached to it.

In general

The pressure zone principle will be more
prominent in a larger frequency range, the
larger the surface the BLM6000 is placed
on. Conversely, you can experiment with a
placement close to the edges of a table, to
the edge of the stage floor or lectern in order
to obtain bass roll off.

If you want to place the disc on a ceiling or
a wall, simply use double-sided tape.

Please find some graphs that illustrate the
frequency response of the microphone
mounted in the BLM.

Mounting the microphone

BLM6000 on floor

DPA4060 in BLM6000 measured on
floor re same microphone measured
in free field position

BLM6000 mounted on piano lid

BLM6000 on desk

20
15
10

Sens.

-5

20

-15

-20

Typical low frequence response of
DPA4060 in BLM6000 in relation to
the boundary area

Frequency response

5
0

Infinite boundary area

Larger boundary area

Limited boundary area

20 31,5 63 125 250

Smaller boundary area

Physical dimensions:

Diameter: 75 mm
Height: 6 mm
Weight (w/o mic): 12 grams

Order numbers:

BLM6000-B, Black
BLM6000-W, White

Note: Tape not included. Take care to
select tape that will not damage the surface
it is placed on.

Freq.

500