Styled in red and suitable for mastering purposes, the PQ from SPL is a parametric equalizer—specifically, it's a redesigned edition of their well-regarded Model 2050 SPL PQ Mastering Equalizer. It features stereo and dual-mono operation as well as five separate bands per channel. These bands can be individually instantiated and separately switched between Constant and Proportional Q modes.

An Auto-Bypass mode allows you to sit back within the sweet-spot of your monitoring setup and simply listen to your changes as the system automatically toggles between effected and unaffected signal. It does this at a rate of your choice. This EQ also features 120V Rail Technology, which helps elicits a mastering-quality technical performance from the unit in terms of headroom, dynamic range, and fine-detail reproduction. Its stepped knobs help you recall your exact settings between sessions. The unit utilizes XLR jacks for its inputs and outputs, and its dimensions ensure you can mount it within your rack.

5-Band Fully Parametric EQ    Dual-Mono or Stereo Operation    120V Rail Technology, Mastering Grade    Proportional or Constant Q    Auto-Bypass Mode    Stepped Knobs for Recall    Rack-Mountable

In each band, the frequency bandwidth can either be set to a static state, or one that grows/shrinks in relation to the amplitude of the cut/boost. In constant-Q mode, the selected bandwidth remains unaffected by the amplitude setting, making it a suitable choice for corrective applications (eliminating unwanted frequencies, for example). In proportional-Q mode, on the other hand, the bandwidth decreases as the amplitude of the band is boosted or attenuated, allowing for more musical choices.

Each channel provides five frequency bands, all fully parametric and independently selectable. Frequency ranges are: 

• LF (Low Frequencies): 10 to 330 Hz
• LMF (Low Mid Frequencies): 33 Hz to 1 kHz
• MF (Mid Frequencies): 128 Hz to 4.1 kHz
• HMF (High Mid Frequencies): 310 Hz to 10 kHz
• HF (High Frequencies): 760 Hz to 24 kHz

To be able to make an objective judgment of processed material, often it is best not to have to toggle between uneffected and effected signal yourself, as this can introduce psychological biases and remove you from the sweet spot of your setup whilst you make choices. Thus, you can induce Auto Bypass, an interval control that determines the time that needs to elapse before the unit toggles between the processed and unprocessed signals. Hard left is the shortest setting. To increase the interval, turn the knob clockwise.

The PQ Mastering Equalizer has been designed as an independent dual-channel equalizer and thus can be used to process two different mono signals at the same time. Nevertheless, you can also process a stereo signal with the link button, which allows you to manipulate both channels in tandem from the right channel.

Related Questions and Answers

Q: 1. How much should I use for a liter of water? I'm developing photograms/lumens

A: The instructions and use for Ilford PQ Universal Paper Developer (500ml) is, https://bit.ly/3sba8td .

Q: 2. Is this hardware version 1.1? If so it will have dip switches on back of unit. This allows home theater bypass.

A: The SPL Elector Preamp has 4 dip switches on the back. This and further details can be found on the SPL product page for the Elector Preamp, linked here: https://spl.audio/en/spl-produkt/elector/

Q: 3. Do these cloths offer any weather, or water resistance

A: Unfortunately, this cloth does not offer any type of weather or water resistance.

Q: 4. Can this be mounted to a tripod? The photo of the back shows what might be a tripod socket, just want to be sure.

A: There is a standard tripod socket on the bottom side of the mic.

Q: 5. can I use this with my laptop to help adjust bass and treble?

A: Yes, the Bellari EQ570 4-Band Audio Equalizer can be used to adjust the bass and treble for your laptop audio.

Q: 6. Is there any way to get on a list for the Z 6II edition of the book?

A: At this time, there have been no announcements regarding an updated version of this book for the Z6 II specifically. In the event that the update will be released, we will notify those signed up for the B&H E-Mail Newsletter.

Q: 7. If I was looking to mix 5.1 audio for post production, would this be a good solution as the interface between my 5 speakers + sub and my computer (running Adobe Premiere and Audition CC)? Would I need any additional hardware? I'm confused over whether something like this, or something like the Focusrite 18i20 is better for my purposes. Or something else? Again, I'm NOT using this to record audio, but only to mix audio for video post production. While 80% of my mixes will be for stereo output only, a small portion will be for 5.1 surround. Please advise.

A: The 18i20 will work much better.

Q: 8. Can this device be used to detect high frequency noise suppressing generators in office buildings?

A: No. The Galaxy Audio CM-170 Check Mate Series Type II SPL Meter is used to measure sound pressure levels (SPL) in decibels. It would only be able to measure the SPL of any equipment.

Q: 9. Can it be used with 230v europlug ?

A: This is a120V AC/60Hz device only.

Q: 10. What is the difference between this and the CM-130 that only costs $59.99? The specs are the same except that this one has lower bass response. What specifically is different in this model warrant double the price?

A: The CM-140 meets IEC 651 Type II & ANSI S1.4 Type II standards while the CM-130 model does not.