The heavy and horizontal Klein + Hummel O 300 monitors need a sturdy monitor stand. At 30
lbs each and costing $5,000 a pair, you don’t want them dropping to the floor from 3
This article is the second in a two part about speaker stands and the
K+H O 300. The first part provides details on Blue Sky
The Stand review
This reprint doesn't contain the links and illustrations
in the original article. If you want the details, link to Building a stand for K+H O 300 monitors
When I got the
monitors in 2009, Studio Economik suggested the Sound Anchors STUDADJR at $800 a pair.
I didn’t get a cheaper solution than Sound Anchors but I did get one that looks
better and has more flexibility in speaker location.
There is a bracket on the
back of the K+H O 300′s that supports wall mounting but no one recommends that for near
field monitors. Reflections off the wall would be too strong at the listening position and
aiming them 30 degrees toward the mixing position a little tricky.
purchased, Klein and Hummel, has a detailed specification K+H Mounting Hardware Matrix
with approved supports that include suspending from the ceiling or mounted on tripod and
mono-pod stands from K+M.
Neumann advise that loading stands with sand to
dampen resonance does nothing. “We do not subscribe to all this “spike your stands”
stuff seen in the hi-fi industry. A solid stand with this hardware is quite acceptable.”
(Andrew Goldberg, Product Manager – Studio Monitor Systems, Georg Neumann GmbH)
Any solution from Neumann was going to cost about the same as the Sound Anchors and
involved a confusing series of adapters.
I tried the K+H O 300s on OnStage
SMS6000 Adjustable Studio Monitor Stands. It was scary to watch them sway in the breeze.
So I built a plywood meter bridge and placed the monitors on the
extreme end of each side. (Fig. 2) That solution was certainly secure. The mixing desk can
support 250 lbs. However, there was no means to experiment with the monitor location to
get the best sound in the room. Right off the bat monitors were about 1 foot too close
Position of the monitors side to side affects the proper stereo image
at the mixing seat, just ahead of the focal point. They are supposed to be set up in an
equilateral triangle with the listening position. The optimum distance is 67.5″ apart,
according to some, which puts the focal point about 3 to 18″ behind your head.
Monitors placed on the mixing desk or meter bridge transmit sound through the desk
faster than through the air. The monitors are subject to low frequency cancellation. That
effect is mitigated by using the Primacoustic RX9 – HF Horizontal Recoil Stabilizer.
The other problem with meter bridge mounting is the sound reflects off
the desk. The tapered angle of Mackie MCU Pro Control Surface, MCU Pro Extension and
Mackie C4 Pro act like the traditional beveled mixing desk to deflect some of the
reflections. (Fig. 3)
The recommended installation is the near field monitors
installed on stands to get the best results.Horizontal or Vertical
Most active near-fields are placed vertically. The 3-way K+H O 300s are designed
to mount horizontally with the tweeters to the outside.
Neumann provide plenty
of technical information in the K+H O 300 manual on frequency response and distortion both
vertically and horizontally. The sweet spot for best response is narrower when mounted on
the vertical. (Fig. 4)The Stand and adaptation
After a year of
putzing with OnStage stands, the meter bridge and almost ordering the Sound Anchors, I
came across Blue Sky’s The Stand. It had everything I needed – large 30 inch base for
stability, capacity to handle 80 lbs, and vertical and horizontal adjustment. Blue Sky The
To make the K+H O 300 secure, I ordered the Neumann LH-25 bracket
specified in the K+H Mounting Hardware Matrix. (Fig. 5) From appearances it seemed like an
easy adaptation to drill a few holes in the mounting bracket on The Stand and bolt them
When the LH-25 and The Stand arrived, a simpler solution presented
itself – remove the Blue Sky bracket (Fig. 6) and install the LH-25 bracket directly on
the top of the chrome cylinder. (Fig. 7)
When I tested the adaption, the thumb
screw didn’t allow the K+H O 300 to pivot vertically. (Fig. 7 )
confirmed, in an email, the thumb screw can be replaced with a 1/4″ bolt (coarse thread)
and washer. I used a hardened 1/4″ x 3/4″ steel bolt, although the original thumbscrew
is not hardened. (Fig. 8 )
Be careful not to over torque the 1/4″ bolt since
it may either break or suffer shear damage and break later. Use only the amount of torque
you would on the thumb screw.
You may wish to keep the original Blue Sky
bracket and attach the LH 25 to it. It seemed redundant and merely added three more bolts
to tighten and without adding any rigidity or features.Installing the
The K+H O 300s come with a plastic screw in each side that must be
removed first. If you take the speaker off the stand later, the plastic screws must be put
The hard plastic handled thumb screw and washers are installed as
illustrated in Fig. 9.
This is a two-person job. One person can hold the 30 lb
speaker and another can thread the supplied bolts, washer and rubber washers.
The biggest problem was holding the speaker in the correct position and not cross
threading the screws.
Hand tighten the plastic covered bolts and no more.
Alternatively, one could place the K+H O 300 on its back, install the screws in
the bracket and stand the assembly up. That seemed a little dangerous so I got my
daughters to help. (See Fig. 1 for fully assembled Stand, LH-25 and K+H O 300)
Alternate mounting brackets
If you pick a mono-pod or tripod stand for the
K+H monitors, there are several other adapters available that will connect with them –
LH 28, LH 29, LH 37 and LH 48. Consult the K+H Mounting Hardware Matrix for details.Putting the speaker and stand in place
This is again a two
person operation. The whole thing is rather unwieldy with the base width, height and
weight. The speaker stand will drop if you lift the from the speaker bracket, which is how
you adjust the height upward. (Fig. 10 )
Once in place, all that was need were
small adjustments of the rubberized feet to compensate for the hard wood floor.Where to buy
Total cost was $600 for Blue Sky The Stand (pair) at
Amazon.com or other dealers and $120 for the LH-25 brackets (pair). Not many dealers
carry the LH-25s but I did find a pair at Studio Economik who ship to the US and Canada.
In Europe, Prosl.com will order them. Most Neumann dealers can order them from Sennheiser,
who own Neumann, although several wouldn’t admit they could.
listing these items as “Each” but you will need a pair of both. That must be to avoid