As the trees begin to bud and a new season unfolds, it’s the perfect time to explore something fresh and inspiring in your creative journey. Today, we’re delighted to share an English translation of the Japanese blog post “Uses of HPL Processor Ultimate” by Mr. Kubo from Acoustic Field Co., Ltd.

Mr. Kubo is a specialist in the development and consulting of advanced acoustic systems focused on 3D spatial sound. He supports sound artists in music production and immersive installation art from a technical perspective. He is also the creator of “HPL,” a high-quality binaural processing technology optimized for listening through headphones and earphones.

Situations Where Using the HPL Processor Ultimate is Beneficial

https://novo-notes.com/hpl-processor

Differences in HPL between 'HPL Processor Ultimate' and 'NovoNotes 3DX', which also implements HPL

3DX possesses aspects of a binaural effector designed for sound creation, while the HPL Processor Ultimate acts as a converter that transforms a finalized channel-based audio into binaural.

When converting a 7.1.4ch mix into binaural using 3DX, as illustrated in the diagram below, it allows for scalability of the balance in terms of left and right, front and back, and top and bottom through its "Scale" feature. Furthermore, it enables shifting the overall balance either front-to-back or top-to-bottom, allowing it to be used as an effector to adjust how the sound is perceived from its original mix balance.

The reason this adjustment is possible is because the channels are in an undefined state of objects. Consequently, the sound image isn't as sharp as the HPL Processor Ultimate when compared.

The HPL Processor Ultimate doesn't allow for such adjustments. Instead, it acts as a multi-channel to binaural converter that delivers a sharp sound image, replicating a mix without any coloration, much like how it would sound in a studio with optimal speaker placement.

When I say "like a studio," I don't mean it captures the essence of a particular studio, as that would imply coloration. What I mean is that it possesses a neutral space that can be used as a reference, enabling studio-like work.

(Excerpt omitted)

I will introduce how I, as the creator and continued user of HPL processing, typically utilize it. Please refer to this for the various uses of HPL Processor Ultimate.

Situations Where Using the HPL Processor Ultimate is Beneficial:

#1 Binaural Release of Mixes from 2ch to 22.2ch

Especially for surround sound compositions, it's not always feasible for a wide audience to listen to them. For people to listen to music produced in formats such as 7.1.4ch, even if it's in a provisional form, binaural processing is necessary. There were elements in the listener-end processing of binaural quality, like Apple's spatial audio, that engineers found unsatisfactory. Being compelled to use certain acoustic products goes against the idea of letting a broad audience listen to the mix. Hence, the HPL binaural processing has primarily been embraced by those who treasure musical compositions.

#2 Mix Monitoring from 2ch to 22.2ch

Perform preliminary mixing using the HPL Processor Ultimate with headphones before entering the studio. By always inserting the HPL Processor Ultimate into the DAW monitor output, you can conduct surround pre-mixes even at home. When this mix is later expanded through speakers in the studio, you'll notice both "identical" and "different" components. You'll become accustomed to this with repeated experiences. Since both the studio and HPL Processor Ultimate provide a neutral sound space, any corrections will be precise.

#3 Mix Checking

An advantage of binaural monitoring is the consistent perfect listening point. This can be used for headphone mixing or to check the balance after speaker mixing. Essentially, even with speakers available, you can check the speaker playback balance deliberately using headphones.

This is particularly effective for 2ch. It allows for confirmation of the LR balance and center positioning while situated perfectly between L/R. You might think this can be verified without converting to binaural, but the balance of a non-binaural 2ch headphone sound is largely distorted. Verifying speaker playback balance with HPL binaural that maintains the 2Mix balance in headphones is useful. Especially with HPL, the center sound is significantly more refined than other binaurals. Given that many listen to music using headphones or earphones today, I believe this method is quite important.

#4 Monitoring in Live Venues

In situations with poor speaker monitoring, HPL headphone monitoring is helpful. FOH (Front of House) and even in backstage areas with significant ambient noise, it can be challenging to monitor delicate sounds through speakers. In such cases, it's often better to monitor speaker playback balance with headphones. Naturally, for surround mixes, setting up a surround monitoring environment can be difficult. Of course, you can also directly broadcast that binaural mix.

If you're using the HPL Processor Ultimate, it would be PC-based, but for those wanting a hardware-based setup, such as for outside broadcasting vans, you can similarly use the HPL Processor, the Airfolc RA-6010-HPL.

#5 At Theatrical and Live Events

During preparations for theatrical and live events, the times when sound can be played are fixed by a timetable. However, with the use of the HPL Processor Ultimate, you can adjust the mix using headphones during waiting times, enabling the creation of a higher-quality acoustic environment within the limited time leading up to the dress rehearsal. Recording rehearsals and adjusting the surround mix using that recording during downtime is a common practice.

For larger venues, using the previously mentioned 3DX's Scale feature to expand the spatial experience of binaural monitoring might be more suitable.

#6 Archiving

In a previous interview with Sunreco [link provided], I discussed "binauralizing memories," and I always convert and keep every surround project I work on in binaural format. If someone wants to later reuse or simply listen to the audio, it's not easy if it's in surround. By storing audio sources that have been binauralized with the HPL Processor Ultimate, you can cater to various requests.

When creating teaser videos, if the content is in surround, you'd likely want to also have the video in binaural.
https://youtu.be/DMCoeyJq-s8

#7 Previewing Atmos Sources and Streams

I usually watch YouTube music lives binaurally processed through HPL. It feels more in sync with the video's spatial sense. With the expected increase in Atmos broadcasts, for such streams, you can loop back the browser's output to a platform with the HPL Processor Ultimate to listen in surround. However, for streams from KORG Live Extreme, since they are already broadcast through HPL, you can listen directly from your browser.

#8 For Personal Use

Whether it's CDs, streaming services, YouTube, radio, or TV, I try to listen through HPL as much as possible. The concept of HPL allows music to be heard in its intended sound, with a proper balance even on headphones. Of course, for visual content, the usual discomfort of sound playing directly into the ears in relation to the screen is alleviated. Even for monaural talk content like radio, it's been said from the start that HPL makes it easier to listen to and reduces fatigue over prolonged listening.

There are challenges like having to loop back from browsers to a platform with the HPL Processor Ultimate, but once you get used to HPL, it's hard to go back. Some users even carry players with all their music processed through HPL.

While the HPL Processor Ultimate is a simple binaural monitoring plugin, such tools are adaptable to various uses. I encourage you to experiment and use it creatively.

Spring into Savings: Discover HPL Processor Ultimate

Our Spring Sale runs until May 11th. The HPL Processor Ultimate featured in the blog is also part of this special offer.

At NovoNotes, we continue to develop plugins that spark creativity and offer immersive sound experiences beyond what’s possible with conventional tools. Why not let this season be the start of your journey into spatial sound? We sincerely hope our tools help your music blossom this spring.

Grab Your Spring Deal

🌸 Spring Sale Ends Today – Still Deciding? Don’t Miss Out

Only 2 Days Left – Save Big with NovoNotes Bundles!

Just 4 Days Left – Discover SideRack Before the Sale Ends!

Countdown Begins – Hear the Power of 3DX

【Spring Sale Ongoing】Plugins Making Waves in the Media — Try Them Now at a Special Price!

See all posts from NovoNotes