Weiss EQ1-LP Equalizer

The Weiss EQ1-LP Equalizer is a Linear Phase 2-Channel Digital Equalizer with seven parametric bands. With exclusive digital inputs/outputs and working at up to 24 Bit/96 kHz, the EQ1-LP is the reference equalizer when it comes to digital mastering EQs.

The Weiss EQ1-LP Equalizer incorporates the EQ1-MK2 with linear phase response. The Weiss EQ1-LP has the same parameter set and features as the Weiss EQ1-MK2. In addition it can be switched between minimum and linear phase behavior. Linear phase means that the delay introduced by processing is constant across the whole spectrum, unconstrained by the EQ settings. The sound, or character, of an equalizer has been said to be influenced by phase response as for example John Watkinson mentioned in Studio Sound magazine 9/97: “… much of the audible difference between EQs comes down to the phase response.” The Weiss EQ1-LP Equalizer is therefore the ideal tool for corrective amplitude adjustment, without the unwanted phase distortion added by standard equalizers.

Adding to the high resolution processing, the Weiss EQ1-LP now features an extended parameter set, significantly increasing the number of possible eq settings, as well as a new operational mode for processing stereo signals in the M/S domain (as compared to processing in the L/R domain).

The Q now reaches from a near whole-bandwidth-covering 0.20 to a needle-like 650 in 128 steps, allowing everything from subtle sound colouring to notch filter tone removal. The boost varies in 0.1 dB steps from -39dB (for notching) to +18dB. To compensate for the extremely accurate notch filter type, the frequency resolution has been doubled, now running from 14Hz to 21kHz in 12th octave steps plus including special notch frequencies such as 50 and 60 Hz and their harmonics.

A further new feature is the settable “shape” parameter for shelving filters, which has the same resolution and a similar effect as the Q parameter for the presence filter type.

Combined with the flexibility of seven independent bands per channel, the mastering engineer can now twist the transfer curve to his exact specifications.

Basic EQ1 Functions

The model Weiss EQ1-LP Equalizer features the seven identical parametric bands, i.e. all seven bands cover the entire audio frequency range. Each band has Boost/Cut, Frequency and Q/Slope knobs and operates in any of the following modes: High shelving, low shelving, peaking, high cut, low cut, bypass.

Controls, Display

There are seven times three knobs in order to have “one knob per parameter” operation. The knobs are touch sensitive to switch the LCD to display the parameters of the touched band. The LCD shows the overall frequency response, the detailed parameter values and various status information.

Snapshots, MIDI, Metering

The Weiss EQ1-LP Equalizer also features an A/B compare memory, a 128 position snapshot bank with two additional banks for back-up (can also be dumped/recovered via MIDI), a peak meter with over indicators, MIDI control for each parameter, an overall bypass switch and an overall gain control, a channel ganging switch.

Signal Processing, Connectivity

The internal processing is done at 88.2 or 96 kHz in a 40 Bit floating-point format. A very low noise filter architecture optimized for audio is used. The digital input/output are in AES/EBU format on XLR connectors. The AES/EBU output can be POW-R dithered to 16, 20 or 24 Bits.

M/S Mode

The EQ1-LP Equalizer can be switched to M/S mode which is especially useful for the dynamic model of the EQ1. Other specialties are variable slope shelving filters and very high Q (up to 650) peaking filters for notching out offending frequencies.

Weiss EQ1-LP Equalizer Features

• Seven identical parametric bands
• All seven bands cover the entire audio frequency range
• Each band has Boost/Cut, Frequency and Q/Slope knobs
• Each band operates in any of the High shelving, low shelving, peaking, high cut, low cut, bypass modes
• One parameter per knob operation
• Seven sets of controls for seven operating bands
• Knobs are touch sensitive
• LCD display shows detailed parameters of the touched band
• Large, backlit Liquid Crystal Display
• Display shows the overall frequency response (calculated in real time) and the detailed parameter values in dB, Hz and Q
• A/B compare memory, 128 snapshot bank with two additional banks for back-up
• Digital input / output in AES/EBU format on XLR connectors
• Dithering to 16 bits POW-R dithering
• 128 steps for boost/cut, frequency and Q parameters
• Variable slope shelving filters
• Very high Q (up to 650) for notching out offending frequencies
• M/S mode for independent equalization of M and S channels
• M/S encoder / decoder can be configured separately
• Peak meter, over indicators
• MIDI control for each parameter
• Bypass, overall gain, CH1/2 independent or ganged

Weiss EQ1-LP Equalizer Specifications

• AES/EBU Input:
  • Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz
  • Maximum input word-length: 24 Bits
  • Channel Status Data: Input accepts professional or consumer format
  • Channel Status Data Bits Forwarded to AES/EBU Output: See table in provided manual
  • Connector: XLR female
• AES/EBU Output:
  • Sampling Frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz (always the same as the input)
  • Output Word-Length: 24 Bits
  • Connector: XLR male
• AES/EBU Channel Status Data Conversion:
  • From Consumer to Professional
  • From Professional to Consumer
  • Transparent mode
• Power:
  • Mains Voltage: 115 V or 230 V with voltage selector
  • Fuse Rating: 500 mA slow blow
  • Power Consumption: 40 VA max.
• Size:
  • Depth: 30 cm
  • Width: 43,3 cm (19")
  • Height: 8,8 cm (2HU)

Weiss EQ1-LP Equalizer Includes

• Weiss EQ1-LP Unit
• Printed User Manual