Grace Design m904B w/ Free Gear - Monitors/Speaker Management

For the requirements of any high quality audio production facility working in stereo, Grace presents the m904B stereo monitor controller.

The Grace Design m904B combines all the same features and technology found in the flagship m906 surround controller, but is for stereo monitoring only. It is a perfect control center for any type of audio production facility - from project studio to world class mastering facility.

The m904B offers a full compliment of balanced and unbalanced stereo analog and digital inputs, the latter featuring our latest generation reference quality 24/192 DAC technology. Like the m906, all inputs and outputs can be user calibrated for seamless integration into any playback environment with all types of playback equipment.

The m904B is configured as a 2U rack chassis, with all system controls built into the unit itself. It comes with a blank 2U rack chassis and a separate remote control unit (m904RCU), just like the m906 system. Additionally, a standard m904 can be used with the m904RCU, with the user able to select between local and remote control.

Also included as a standard feature is Grace's critically acclaimed m902 headphone amplifier circuitry, with two output jacks on the mainframe and one additional output on the m904RCU. This circuitry provides true audiophile headphone amplification for critical monitoring, mixing and quality control.

While the m904B provides an astounding compliment of useful features, the real achievement for Grace was to implement all of this while maintaining impeccable high fidelity audio performance.

The m904 and m904B are designed and built to empower audio professionals with the highest performance and most comprehensive feature set that any monitor control systems have to offer.

Specifications:

ANALOG INPUT
THD+N @ 0dB gain, 1kHz
+20dBu out	<0.001% (0.00075% typical)
+10dBu out	<0.003% (0.001% typical)
0dBu out	<0.009% (0.005% typical)

Intermodulation Distortion SMTPE/DIN 4:1 50Hz, 7kHz
@+20dBu out	<0.002% (0.0015% typical)
@ 0dBu out	<0.008% (0.006% typical)

Frequency Response
+/-3dB	3Hz - 250Khz

Dynamic Range
20-22kHz bandwidth	112dB
20-22kHz bandwidth and A weighting filter	115dB

Output Noise
20-22kHz bandwidth, -20dB gain
High gain mode	-89dBu
Low gain mode	-98dBu
20-22kHz bandwidth and A weighting filter, -20dB gain
High gain mode	-91dBu
Low gain mode	-99dBu

Phase Deviation
20Hz to 20kHz	< 4Â°
10Hz to 100kHz	< 15Â°

Crosstalk any channel
100Hz	< 100dB
1kHz	< 100dB
20kHz	< 85dB

Balanced Input CMRR
60Hz	> 65dB
1kHz	>65dB
10kHz	>60dB

Gain Range
Low gain mode (0.5dB steps)	-105.5dB to +20dB
High gain mode (0.5dB steps)	-95.5dB to +30dB

Channel Tracking Accuracy
Any channel	+/-0.05dB

Maximum Output Level
Low gain mode (balanced)	+15dBu
High gain mode (balanced)	+27dBu

Maximum Input Level
Balanced inputs	+30dBu
Unbalanced inputs	+20dBu

Impedances
Balanced inputs	30k Ohms
Unbalanced inputs	50k Ohms
Balanced outputs	300 Ohms
Minimum load impedance	300 Ohms

DIGITAL TO ANALOG CONVERTER FIXED OUTPUTS
Output Levels
User selectable (0dBFS)	+16dBu / +24dBu
Fixed output trim range (0.5dB steps)	-95.5dB to +30dB

THD+N
1kHz, -1dBFS, 20-22kHz bandwidth (44.1kHz)	0.00%

Dynamic Range
20-22kHz bandwidth	>111dB

Input Lock Range
AES3/SPDIF	32kHz to 192kHz
TOSLINK	32kHz to 96kHz
ADAT LIGHTPIPEâ„¢	30kHz 55kHz

s-Lockâ„¢ Sample Clock Intrinsic Jitter
20-22kHz bandwidth	<25ps

s-Lockâ„¢ Sample Clock Jitter Rejection
1kHz sine jitter	-40dB

s-Lockâ„¢ Supported Sample Rates
AES3, SPDIF	44.1, 48, 88.2, 96, 176.4, 192kHz
TOSLINK	44.1, 48, 88.2, 96kHz
ADAT LIGHTPIPEâ„¢	44.1, 48kHz

s-Lockâ„¢ Capture Range
44.1, 48kHz	+/- 10Hz
88.2, 96kHz	+/- 20Hz
176.4, 192kHz	+/- 40Hz

Word Clock / Superclock Input
Impedance (switchable)	75 Ohms / 1M Ohms
Minimum Voltage	3V peak to peak
Maximum Voltage	5V peak to peak
Word clock frequencies supported	44.1, 48, 88.2, 96, 176.4, 192kHz
Superclock frequencies supported	11.2896MHz, 12.288MHz (256x fs)

POWER SUPPLY / MECHANICAL SPECS
Power consumption	30W
Input Voltage 50-60Hz	100, 120, 220, 230-240VAC

Dimensions
Main chassis IEC 2U	3.5" x 10.5" x 17"
Remot control unit	1.6" x 8" x 5.25"

Weight
Main chassis	14.1lbs / 6.4kg
Remote control unit	2.3lbs / 1kg

Sennheiser HD280 Pro Headphones

The HD280 Professional is Sennheiser's most significant closed, circumaural headphone to be introduced in years. Designed to exceed the demands of the professional environment, the HD280Pro boasts extremely robust construction combined with extensive features that meet the requirements of today's most demanding applications. The unique collapsible design combined with swiveling ear cups, offers maximum flexibility in any application. Features Closed, dynamic stereo headphones Accurate, linear sound reproduction for critical monitoring applications.

Specifications:

Optimum impedance ensures universal compatibility
Space saving design features collapsible, rotating earcups
Up to 32 dB of ambient noise attenuation
Neodymium magnets for high maximum SPL
Single-sided, coiled cable with 3.5 mm mini jack with locking 1/4" adapter
Very comfortable, even if used for long periods of time
Rugged construction with user-replaceable parts
2 year warranty