MACKIE HM-4, HM-400, HM-800 HM Series FAQ.pdf

HM Series

FAQ

http://mackie.com/products/hm-series

What models are featured in the HM series?

The HM series consists of three different headphone amplifiers:

• HM-4 – 4-Way Headphone Amplifier

• HM-400 – 4-Channel Headphone Amplifier

• HM-800 – 8-Channel Headphone Amplifier

How many headphones/monitors can I connect at one time?

The HM-4 has four TRS headphone outputs allowing you to share a signal line-level source with up to four people. You also
have an independent volume control for each of the four outputs.

The HM-400 has up to 12 total headphone outs. There are three 1/4″ outputs on each channel, four fully independent
headphone ports on the front of the unit and two additional headphone ports per channel on the back of the unit.

The HM-800 has up to 16 total headphone outs. There are two 1/4″ outputs on each channel, eight fully independent
headphone ports on the front of the unit and an additional headphone port per channel on the back of the unit.

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HM Series

What are the input/output impedances of these headphone amplifiers?

HM-4

• Input: 10k ohms

• Output(s): 47 ohms

HM-400

• Main Input(s): 20k ohm balanced, 10k ohm, unbalanced

• Aux Input(s): 10k ohm, unbalanced

• Headphone Output(s): 3 ohm unbalanced

FAQ

http://mackie.com/products/hm-series

• Main Output: Straight Through

HM-800

• Main Input(s): 40k ohm balanced, 20k ohm, unbalanced

• Aux Input(s): 13k ohm unbalanced

• Headphone Output(s): 3 ohm unbalanced

• Main Output: Straight Through

What is the frequency response of the HM Series Headphone Amps?

Frequency response on all models HM-4, HM-400, and HM-800 is 20Hz – 20 kHz +/- 1dB

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FAQ

HM Series

http://mackie.com/products/hm-series

Can I add a separate input to each channel?

HM-4
No. The HM-4 only has a single 1/4-inch TRS input.

HM-400 and HM-800
Absolutely! The HM-400 has 4 ¬ 1/4-inch aux inputs, one per channel, on the front of the unit. This allows for additional input

stereo signals from the aux outputs, or aux sends, of an external mixer to be fed into the Aux Input jacks of this HM-400.

The HM-800 has 8 ¬ 1/4-inch aux inputs, one per channel, on the back of the unit. This allows for additional input stereo
signals from the aux outputs, or aux sends, of an external mixer to be fed into the Aux Input jacks of this HM-800.

Are the inputs and outputs of the HM Series headphone amps balanced or unbalanced?

All of the inputs and outputs, both TRS and XLR, on all three models (HM-4, HM-400, and HM-800) are balanced. They can be
used with unbalanced cables if needed though.

Can I run the HM Series headphone amps in mono?

HM-4
This headphone amp has a single 1/4-inch TRS stereo input but can be used with a TS connector if necessary with no option

for mono summing.

HM-400 and HM-800
Both of these models have a stereo/mono selector button on the front panel for each channel. This allows you to switch

between a stereo input and mono summing.

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FAQ

HM Series

http://mackie.com/products/hm-series

Can the HM series headphone amps be rack mounted?

HM-4
No. The HM-4 headphone amp is already very small and compact, which should allow it to be placed anywhere in your studio,

stage, or rehearsal space without taking up too much space.

HM-400 and HM-800
Yes! Both the HM-400 and HM-800 headphone amps are built with a rock-solid, rackmount design and come with rack ears

built-in to be placed in your favorite rack. In addition, the HM-400 and HM-800 will only take up 1RU of space in your rack.

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