Wednesday, June 30, 2021



I’ve been using the Presonus Quantum 4848 audio interface for over a year and I’m very impressed with its performance. Presonus has created an extraordinary interface with unique and unmatched features. Their engineers have optimized the Thunderbolt connection so you don’t need a DSP mixing layer for monitoring latency-free while recording tracks. 


I record on a Mac Pro using Logic X. The output of my DAW feeds a 40 channel Soundcraft analog console. 

The Quantum 4848 is packed with unique features. It is a single rack space box with 32 balanced inputs and outputs which appear on eight 25-pin D-sub connectors. In addition to the analog I.O. you also get 16-in and 16-out available on ADAT optical connections. These optical connections are compatible with inexpensive Behringer ADAT preamp boxes (I own three of them). With a pair of ADAT 8-channel preamp boxes connected you can access 48-channels of inputs and outputs simultaneously. 


By taking advantage of the high-speed Thunderbolt 2 interface Presonus has overcome one of the biggest impediments in modern recording. They have eliminated the DSP mixing layer which every other DAW implements to monitor without latency. When you setup the Quantum 4848 you set your buffers to the smallest setting so data can flow through unimpeded. Once installed and configured you can just select input monitor in Logic and you’re listening to the output of the Quantum in real-time. 

Before I bought the Quantum I mixed with the buffers in Logic set to 128 or 256 and the latency monitoring through the software at these settings was unacceptable for cutting real-time tracks like lead guitar or vocals. I used hardware monitoring through my analog console to achieve real-time monitoring while recording but it was always a hassle to connect and manipulate all those analog connections. 

After initially installing the Quantum 4848 I set the buffers as low as they would go and Logic indicates my roundtrip latency is less than 2 milliseconds. Monitoring through the Logic DAW is virtually real time. 2ms of latency is like what a drummer hears from his snare drum which is approximately 2.2 feet from his ears. Typically we call that “real time”. 

The first time I powered up a session in Logic using the Quantum 4848 I cringed expecting it to lock up or do something weird. A glance at the CPU activity pumped my fear, there was low-level constant cpu usage indicated where previously there was rarely any at all. With experience and more use my fear turned to joy. I see low-level CPU usage all the time when Logic is running through the Q4848 but after creating some epic mixes using tempo-changes, lots of virtual instruments and a bunch of recorded guitar tracks the CPU indicator remains relatively constant and the system has never choked or done anything gross.

When cutting guitar, bass, drum or vocal tracks I don’t hear or feel any latency. It’s like a miracle. The Q4848 has been transparent in use. I don’t fear crashes or weird stuff anymore. The system just works and I’m creating new sounds and songs like never before. 


The Q4848 is for anyone who appreciates having a lot of analog balanced inputs and outputs attached to their DAW. To take advantage of all those inputs and outputs you’ll also need eight D-25 snakes. My Q4848 is cabled up with eight Hosa D25 to TRS snake cables for easy connection to the console patchbay. 

The Q4848 uses the 0-dBu reference level which matches perfectly to my Soundcraft mixing console. 

The Quantum 4848 is packing 32 analog inputs and outputs. I really like all the inputs and outputs this DAW audio inteface provides but the realtime monitoring is the real star of the show. I’ve never liked the DSP monitor mixer on any audio inteface and that goes for the uber expensive Apogee Symphony II.

The Quantum has no touch screen or any controls at all on the front panel except for the power switch. It does not need any, it is transparent in operation once you get everything setup and configured.


I needed to turn off Auto Punch and Auto Record in the Record menu so that monitoring could work from the stock mixer layer in Logic. Before changing these setting the monitoring through the Q4848 was backwards and did not function correctly at all. As soon as I defeated these features monitoring through the Q4848 worked perfect. If anything this is a quirk in the Logic default settings and not a reflection on the performance of the Q4848.


There are no preamps of any kind in the Q4848. The 32 input and output connections on the Q4848 are line-level, analog audio referenced to 0-dBu. This means 0-VU = zero dBu in signal level. The maximum input level is +18dBu although I regularly hit it harder than +18dBu when mixing, careful examination of the recorded waveform did not reveal any clipping. 

The inputs to my Q4848 can be fed from a variety of line level preamp sources in the console patchbay. The 32 outputs from the Q4848 feed the first 32 inputs on my Soundcraft mixing console. The one-to-one association between the Q4848 outputs and the console input channel strips makes routing and mixing straightforward and intuitive. 


That is a lot of D-Sub connectors on the back of the Q4848 single rack-space package. The weight of the D-Sub cables needs to be externally supported. If you land the D-sub connectors and let the eight cables hang off the rear of the interface I predict you’ll develop connection problems over time. I have support bars in the back of my racks which carry the cable weight, the cables go straight into the Q4848 and the weight is kept off the D-Sub connectors. I’ve never had a single connection problem with the Q4848. 


The Presonus Quantum 4848 is a great sounding DAW audio interface and it does not have a sound of its own. The transparency of the audio was an immediate attraction when I first started listening to this interface. I was comparing the audio output to the much more expensive Apogee Symphony II system and I was shocked how good the Presonus sounded in A-B comparisons to the Apogee.

The 0-dBu reference level is a perfect match for my GB-8 Soundcraft mixing console. I’ve never been happier with sound quality and ease of use before pairing the Quantum 4848 with the Soundcraft GB-8 mixing desk.

I spent quite a few hours comparing playback from the Apogee Symphony II in my mastering rack to the Presonus Quantum 4848. I have to say I was really shocked and surprised how good the Q4848 sounds. I’ve been using Apogee converters since the AX series from the early 2000 era. The Symphony II system was a really great sounding converter when it hit the market but time has marched on and others have figured out how to make excellent sounding systems.

This is my first piece of Presonus kit. Prior to owning this Q4848 I viewed this company’s products as second-rate budget priced studio gear. Wow, was I wrong. The Q4848 is so easy to use and so great sounding that I sold off the Apogee Symphony II system.

I would also like to point out that Presonus is down the road from Louisiana State University. Presonus has the pick of the crop of digital design graduates and a wonderful musical campus for them to play and grow in. 


I think every piece of gear needs to be evaluated on its own merit and quality. The Presonus Quantum 4848 wins on every level imaginable. It’s a bargain, it offers the most inputs and outputs for the buck compared to any other manufactuer. The sound quality is competitive with interfaces that cost four-to-six times as much. The hardware build seems solid, only time will tell on this. The ability to monitor through your DAW in real-time without a DSP mixer layer is extraordinary and a God-send to analog mixing console users.

If what you crave is a lot of high quality DAW inputs and outputs the Presonus Quantum 4848 has a lot to offer.

Thanks for reading High on Technology, Good music to you!

This article is ©June 2021 by Mark King. It’s not ok to quote or copy without written permission.