Engineers sometimes advocate using high-pass filters to clean up the low end and tighten the sound. Others believe that because of issues inherent in highpass filters, they should be used sparingly, if at all. So, who's right? Well, as with many aspects of audio technology, they both are in some ways. Let's dive deeper, and then explore Studio One's clever highpass filtering solution.
But before getting into the details, let's look at the big picture. Joe Gilder did a video called THIS is Eating Up All Your Headroom in Your Productions where he shows how low-end energy can accumulate and reduce headroom with no sonic benefits. This is why engineers often apply a highpass filter to a final mix. So, let's look at the sources that can lead to this accumulation of low-frequency energy, and the right way to fix them within individual tracks before they start accumulating in your final mix.
The Case for Highpass Filtering
Sometimes, low-frequency artifacts that you don't want travel along with your audio. One potential issue is a directional microphone's proximity effect, where getting closer to the mic boosts bass unnaturally. Hitting guitar pickups accidentally can generate low-frequency sounds. Transposing samples down by a couple octaves may put energy in the sub-sonic range and even if you can't hear sub-sonic audio, it uses up headroom.
Highpass filtering has other applications. Too many instruments overlapping in low-frequency ranges can create a muddy sound. For example, you might want to reduce some of a guitar's low frequencies to avoid interfering with bass. This is usually what people mean by tightening up the sound.
The Case Against Highpass Filtering
Analog filters produce phase shifts, but the phase shifts in highpass filters with steep slopes are particularly drastic around the cutoff frequency. Most digital filters model analog filters, so they also have phase shifts. Fig. 1 shows a typical example of phase shift in a digital highpass filter with a 100 Hz cutoff and a 24 db/octave slope. The bright line is the filter curve, the darker line shows the amount of phase shift.
Figure 1: Phase shift around the cutoff frequency of a 24 dB/octave highpass filter. The horizontal axis goes from 20 Hz to 20 kHz, so the phase shift impacts the audio well into the midrange. The vertical axis covers -180 degrees to +180 degrees of phase shift.
Wow! That looks scary, doesn't it? It would look even scarier if the slope was steeper than 24 dB/octave. Fortunately, our hearing can't detect phase changes-unless the audio interacts with other audio. This is why if you set a phase shifter effect's dry/wet control to all wet or all dry with no modulation, the sound is the same. You hear the phase-shifted effect only when there's a mix of wet and dry sounds.
When mixing, this phase shift can matter if two signals with similar waveforms are in parallel. For example, consider bass through a DI in parallel with bass through an amp, or two mics at different distances from an acoustic guitar or group of backup singers. The worst-case scenario is multiple acoustic instruments being recorded simultaneously in an acoustic space-the inevitable leakage means the various tracks will have quite a bit of audio in common.
Differing mic distances from a source will cause phase shifts anyway, but using a typical highpass filter (e.g., to reduce p-pops with vocals) will accentuate the phase shifts. In either case, if the parallel tracks have enough audio in common, when they're mixed together phase shifts will alter the sound.
Solution #1: Don't Worry, Be Happy
In many cases, tracks won't be in parallel with other tracks that have similar or identical audio, so there won't be any audible degradation from phase changes caused by a highpass filter. If using a highpass filter does introduce phase problems, cutting with a shelf or peak filter instead can reduce the low frequencies (albeit not in the same way). These filter types produce less drastic phase changes.
Solution #2: The Pro EQ3's LLC Filter
Highpass filters with steep slopes are popular because of their ability to remove bass artifacts and tighten up the sound. But if you need to tighten up or reduce bass artifacts with multiple tracks, inserting all those highpass filters will contribute significant phase changes. Phase variations in the bass range can be a problem (as anyone who's tried to mix in a small, untreated room knows), so it's unfortunate that highpass filters are the best choice for solving these problems.
However, linear-phase highpass filters don't produce phase shifts-that's their outstanding characteristic. You can use as many linear-phase highpass filters as you want, and not introduce any phase shifts.
But that has its own complications, because linear-phase filters require a lot of processing power. Using several multi-stage, linear-phase EQs in a project can bring your CPU to its knees pretty quickly, as well as introduce an annoying amount of latency.
This is why Studio One's solution is particularly elegant. The Pro EQ3 has a single linear-phase highpass filter stage (fig. 2). This covers the most common need for a linear-phase filter in most projects, without the CPU burden of a multi-stage linear-phase EQ where you may not need linear-phase operation for the other stages anyway.
Figure 2: The LLC linear-phase highpass filter (outlined in white) is producing the low-frequency cut outlined in light blue.
Enabling the LLC stage contributes about 31 ms of latency compared to the 50-100 ms from a typical multi-stage linear EQ, and takes care of the frequency range where you're most likely to need a linear-phase EQ. If adding the LLC filter is still too CPU-intensive for a project, or if the latency is bothersome, you can alway
Most recent headlines
06/10/2025
France T l visions, France's leading broadcaster, has received the 2025 EBU ...
04/09/2025
Monumental Sports & Entertainment (MSE), in collaboration with Dalet, has been a...
07/08/2025
July 8 2025, 22:30 (PDT) Tata Motors & Dolby Bring Dolby Atmos to Harrier.ev, R...
15/07/2025
L3Harris put its CORVUS-RAVEN counter-small UAS capability into the hands of soldiers at VANAHEIM, showcasing its ability to provide passive signal detect, enha...
15/07/2025
Netflix Viewing Up 13.5% vs. May, Represents 42% of Monthly Gain for Streaming
...
15/07/2025
SAN FRANCISCO and BENGALARU, India Sangeeta Chakraborty has been named chief revenue officer at Amagi, a cloud-based software-as-a-service (SaaS) technology pro...
15/07/2025
As part of its mandate, the Advanced Television Systems Committee the U.S. organization tasked with developing advanced broadcast TV standards promotes ATSC 3.0...
15/07/2025
QuickLink, the leading global provider of multi-camera video productions and remote contributions, announces the launch of two innovative control panels Studi...
15/07/2025
Chris Kontopanos has joined leading high-quality microphone solutions manufacturer, DPA Microphones, as the company's new Regional Sales Manager for the Mid...
15/07/2025
Magnifi by VideoVerse, a global leader in AI-powered video automation, has launched a major platform upgrade built to simplify live and archival video editing f...
15/07/2025
Telestream, a global leader in media workflow technologies, will preview its latest innovations at IBC2025, Stand 7.B21. This year's showcase highlights how...
15/07/2025
IBC2025 is set to transform the onsite experience for its global attendees with the launch of a pioneering new feature: full integration of Amsterdam's GVB ...
15/07/2025
Music, sport and technology collided in spectacular fashion as ASB GlassFloor powered the debut of Beats N Buckets, Germany's first Basketball meets Hip-Ho...
15/07/2025
The Collectv, the Emmy award-winning broadcast solutions and workflows consultancy - and winner of Broadcast Tech's Team of the Year is delighted to announc...
15/07/2025
SipRadius, the expert in secure, low latency media transport, will showcase how broadcasters and media companies can take control of fragmented IP workflows at ...
15/07/2025
Appear, the global leader in live production technology, today announced its strategic partnership with beIN ASIA PACIFIC, a leading multi-platform sports media...
15/07/2025
Company marks 15 years of innovation at the show
Broadpeak, a leader in streaming and monetization at scale, will return to IBC (Hall 1, Stand F83. RAI, Amster...
15/07/2025
New software solutions extend trusted timing measurement across broadcast, venue, and professional AV applications
Hitomi Broadcast, the market leader in audi...
15/07/2025
SHENZHEN, China Telycam has added control options for its portfolio of pan-tilt-zoom (PTZ) cameras with a new plug-in for Elgato's Stream Deck family of con...
15/07/2025
MELVILLE, N.Y. Chyron said its Chyron LIVE cloud-native live production solution has successfully completed the Amazon Web Services (AWS) Foundational Technical...
15/07/2025
PHILADELPHIA The Xumo streaming platform joint venture between Comcast and Charter has announced the nationwide launch of a new line of Xumo TVs from Westinghou...
15/07/2025
LONGMONT, Colo. DPA Microphones said Chris Kontopanos has joined the microphone solutions provider as its new regional sales manager, Mid-Atlantic....
15/07/2025
NOT FOR DISTRIBUTION IN OR INTO OR TO ANY PERSON LOCATED OR RESIDENT IN THE UNIT...
15/07/2025
Harmonic's Hybrid, AI-Powered and Live Sports Streaming Innovations are Key ...
15/07/2025
The well-known and well-loved 4099 has been completely revamped. It features amazing CORE+ technology, which eliminates distortion and extends dynamic range, a ...
15/07/2025
Comscore Partners with HyphaMetrics to Launch Advanced Person-Level Audience Mea...
15/07/2025
Peak audiences of over half a million tune into both Kerry v Tyrone and Donegal ...
15/07/2025
PROTON Announces Production Facility Expansion Ahead of IBC2025 posted: 15/07/2025
Proton Announces Production Facility Expansion Ahead of IBC2025
Alongs...
15/07/2025
Submissions for NVIDIA's Plug and Play: Project G-Assist Plug-In Hackathon a...
14/07/2025
The Royal Moroccan Air Force hosted a C-130 award ceremony with L3Harris Technologies President of Intelligence, Surveillance and Reconnaissance Jason Lambert a...
14/07/2025
UK launch set for September, following on from recent US and Germany releases
London - UK, July 14, 2025 - Nielsen, a global leader in audience measurement, da...
14/07/2025
SHENZHEN, China Telycam has added control options for its portfolio of pan-tilt-zoom (PTZ) cameras with a new plug-in for Elgato's Stream Deck family of con...
14/07/2025
The awards are open to IBC2025 show exhibitors and offer a valuable platform for companies to raise awareness for the new products and solutions they will be la...
14/07/2025
Clear-Com is excited to announce a significant expansion of the award-winning Arcadia Central Station with new software updates. Together, these releases dram...
14/07/2025
Grass Valley and Daktronics today announced a strategic technology partnership that unites Grass Valley's live production expertise with Daktronics' lea...
14/07/2025
Cloud playout solutions provider, Veset, and swXtch.io, provider of cloud-based multicast and reliable networking solutions, are partnering to deliver multicast...
14/07/2025
Tintri , a DDN subsidiary and leader in AI-powered data management solutions, today announces a game-changing and award-winning refresh to its global Partner P...
14/07/2025
HighField AI, the broadcast industry's first agentic and multimodal AI platform for automating graphics production, is now commercially available. Developed...
14/07/2025
Encompass Digital Media has today announced that it has been delivering a complex global services project for DAZN, the world s leading sports entertainment pla...
14/07/2025
MASV (massive.io), the fastest, most reliable large file transfer platform trusted by over 10,000 global organizations, announced today it will showcase its nex...
14/07/2025
Calrec is introducing a series of usability, customisation and system enhancements across the entire range of Argo consoles at IBC 2025, on Stand 8.C47. Look ou...
14/07/2025
Fincons Group, IT business consultancy and systems integrator company with more than 40 years of experience in the market, is proud to announce a new engagement...
14/07/2025
Intinor returns to IBC to present the latest updates to its Direkt series. A key development on show is Intinor Direkt Management (IDM), a web-based interface f...
14/07/2025
This month, NVIDIA founder and CEO Jensen Huang promoted AI in both Washington, D.C. and Beijing - emphasizing the benefits that AI will bring to business and s...
14/07/2025
Sony's New Coach's Headset Was Designed in Collaboration With the NFL Featuring a custom dynamic boom mic, the headset will debut in the fall By Dan Da...
14/07/2025
Live From MLB All-Star 2025: MLB Network's Marc Caiafa and Tom Guidice on th...
14/07/2025
Back to All News
Netflix ISP Speed Index for June 2025
Product
14 July 2025
Global
Link copied to clipboard
One percent of Internet Service Providers (ISP...
14/07/2025
Back to All News
Netflix Begins Filming The Map of Longing With Al cia Falc , P...
Engineers sometimes advocate using high-pass filters to clean up the low end and tighten the sound. Others believe that because of issues inherent in highpass filters, they should be used sparingly, if at all. So, who's right? Well, as with many aspects of audio technology, they both are in some ways. Let's dive deeper, and then explore Studio One's clever highpass filtering solution.
