CEntrance is the U.S. company that is most pushing into high-end but affordable mobile products suitable for Broadcast, Podcasting, Youtuber, Streaming, or Field Recording.
CEntrance The English Channel is a hardware bundle of three components: SoapBox, an analog preamplifier with dynamic section; BlackCab, mono analog parametric eq; and the PortCaster stereo audio interface, the subject of this article. Nothing prohibits changing the audio interface model from among those stereo interfaces already in production by CEntrance, including the excellent MixerFace most suitable for musicians. The system is modular, because the three components are to be connected together with audio cables, supplied as standard, and USB cables for power.
The English Channel arrives in a sturdy case, which contains the platform to which the three components can be screwed. As standard, in two separate cases, we find two one-meter USB-C cables, two more short USB-C cables to connect SoapBox, BlackCab and the interface together exclusively for power, two cables with XLR connectors for audio connections and two USB C to USB B adapters. The whole system is truly portable and very compact-there are no hidden controls. The switches, which are used for settings and then can be forgotten during transmission and recording, need the common cell phone tool for sim extraction, which comes standard in the package. The last component is the small 24-watt Anker +IQ power supply with two USB-A outputs for power.
CEntrance positions The English Channel in the mid- to high-end broadcast sector, offering a professional solution for those who work with their voice, including Voice Over, and require a functional and portable audio system on all occasions. Suffice it to say that power, again via USB C, can also be provided by a power pack.
Whether it is Digital Streaming, Radio Broadcast or Field Recording does not matter. The English Channel is so flexible that it meets any need, including that of a very good front-end audio system for digital reflex camera (DSLR) dedicated to their audio input.
SoapBox, il pre con le dinamiche
As with all CEntrance modules, SoapBox also follows the rule of connections on the rear panel (Combo input and XLR output) accompanied by a small On/Off switch (to save on power supply) and a small wheel for the intensity of the LEDs. The front panel includes microswitches to activate the high-impedance input (guitarists and bassists will be happy to know this), the HPF filter, the 48 Volt power supply and the pad. Three LEDs are dedicated to monitor the use of the gate, compressor and de-esser, controlled on the panel. For the compressor you control the amount of gain reduction, for the Noise Gate the threshold and for the De-Esser the frequency between 5 and 8 kHz and the amount of compression. There are no timings, compression ratios or thresholds to calibrate: everything has already been set up by CEntrance for the best possible vocal result. Clipping occurs 3 dB above the preamp's red LED. The compressor and de-esser threshold is set at 0 dB VU, i.e. the last green LED at zero. The other two panel controls concern Gain from +10 to +70 dB and Dry/Wet Mix.
If several SoapBoxes are used, it is possible to connect the sidechain signals via a TRRS cable and to determine, for each SoapBox, whether the sidechain, independent for compressor, gate and de-esser, will be the local one or the one received by the TRRS input. For this purpose there are the three microswitches Gate, Comp and De-esser to decide the behaviour of the sidechain. Furthermore, in addition to the input for the three sidechain signals there is also the corresponding output, so that several SoapBoxes can be managed in cascade. This is not a function that is so easily found, quite the contrary! The last three connections concern the USB C input for power supply only and its Thru output to daisy-chain the power supply to the next module, and a mono Line output on mini jack.
BlackCab, l’equalizzatore
Monophonic, the equaliser has three parametric bands, with independent frequency, Q (-9/+9) and gain (-4/+8dB). The band for high frequencies (HF) ranges from 2.4 to 16 kHz, the one for the midrange (MF) from 437 to 2900 kHz and the last one for the low end (LF) from 72 to 800 Hz. Four LEDs indicate the input and output level (white LED from -30 to -6 dB) and peak input and output level, with clipping at +6 dB above the red Peak LED. That's not all, because four microswitches enable the 128 Hz 12 dB/Oct HPF filter, a shelving for high frequencies, the pad to reduce the output level and the bypass.
Already in this way it would be a very good portable eq, given its size, but CEntrance has thought of a couple of extra functions: there is in fact a dual Mono Line Out on a TRS mini-jack cable that is designed to be connected to the Portcaster's stereo Aux input, so as to free up the two XLR inputs on the audio interface. In this way, The English Channel actually has three independent microphone inputs: one comes from SoapBox connected to BlackCab whose Line Out will be used as the Aux input, and the other two inputs are those of PortCaster that remain free. Here again we see the flexibility inherent in The English Channel!
As on SoapBox, also on BlackCab we find the two USB-C connections for power, a Combo input, an XLR output and the power switch.
PortCaster R4S, between analog and digital
PortCaster is designed for those who work with voice every day, so radio and video journalists, podcasters, voice over, real-time online streaming or mobile broadcast for the audio side.
Constructed of solid aircraft-grade metal with minimal dimensions, it packs a pair of quality preamplifiers in its shell, with the option to exclude the second preamp in favor of a TRRS input for smartphones, two analog optical limiters, a headphone output with dedicated amplifier, a line output that can be switched for DSLR audio input level, an auxiliary stereo input, and a dual A/D converter for USB connection and internal recorder on SD card. The interface is completed with the D/A converter that receives the digital signal from the connected device and can be mixed with the incoming analog signals. PortCaster is compatible with iOS, macOS (native, no driver required), Android and Windows with ASIO/WDM drivers.
Controls
PortCaster has controls both on the front panel, with potentiometers and switches, and on the front panel, with switches and buttons for the SD recorder. The small switches are designed for functions that are set only once, with the help of the tip of a ballpoint pen or the more classic open paperclip. Once set up, you will only use the potentiometers, which provide the two gain controls for preamp and TRRS input, Mono/Stereo blend of analog inputs (many applications still use a streaming mono signal), blend between analog inputs and stereo channel return from the USB (DAW) port, AUX 3 and 4 analog stereo input level, and headphone volume. It doesn't get any simpler than that!
On the front panel there are the switches to activate the independent limiters, the HPF filter common to the two preamps, and the replacement of the second preamp with the TRRS input, which deserves an explanation: the call on the cell phone thus connected will provide the voice of the person answering to the internal analog mixer and, at the same time, send the signal of the internal mixer to the phone, excluding, however, the voice of the person on the phone (Mix Minus function). Cleverly, PortCaster does not resend the smartphone's input signal to the smartphone, so those on the other end of the phone do not hear their own voice as a return. The level of the input signal from the phone is controlled by the Gain 2 potentiometer. Goodbye to those sad microphones leaning against the small smartphone speaker that we so often see on television! A very effective way to record or input a call from a smartphone without the need for other connections. All input signals on PortCaster (the microphone, DAW return, and Aux 3 and 4 inputs) can be sent to the smartphone or device connected.
On the front panel there are controls for the audio recorder, the switch for Phantom power for both microphones, the mono switch for headphones, and the switch to convert the Line output to Mic signal for audio connection to digital reflex camera.
R4S Connections
The rear panel accommodates the two Neutrik XLR inputs for as many microphones. The second input can be bypassed to use the nearby mini TRRS jack (XLR/Phone switch on the front panel) we have already written about.
The inputs did not end there: on the front panel there is a stereo mini jack for two line signals that are mixed with the others with the Aux 3-4 pot. Next to it, we find the stereo Line Out and the headphone output, both on mini-jack. The inputs can be monitored in real time, without latency, thanks to the Input/USB pot that balances the analog inputs against the USB return signal. The two USB-C ports are intended, as mentioned, for power and connection to devices (smartphones, tablets, and computers).
R4S Hardware
PortCaster is a little analog and digital gem: the preamplifiers are a custom design by CEntrance (Jasmine, with 1 kOhm impedance) based on dual-stage transistors with 65 dB gain, the HPF filter is fixed at 150 Hz at 6 dB/Oct, the analog limiter is based on a photoelectric cell (optical), and the headphone output benefits from a dedicated amplifier (AmpExtreme) of 400 mWatts at 32 Ohms with 1 Ohm impedance capable of driving headphones from 16 to 600 Ohms. The optical limiter has a soft knee curve, which applies independently to the two audio inputs (also applies to the TRRS connection).
Line output is fixed at +7.1 dBu (0 dBFS) but can be reduced by 46 dB to accommodate the audio input of digital SLR cameras, so as not to saturate the analog input. When using the output in High mode, the impedance is 100 Ohms, while choosing Low, for connection to DSLRs, the impedance is lowered to 50 Ohms so that the signal is properly handled by the audio input.
The digital section is no less impressive: the D/A A/D converter on USB can work at 16 or 24 bits, with sample rates up to 192 kHz. The internal recorder works fixed at 24 bit 48 kHz and records a stereo WAV file, independent of the USB connection, so you can record simultaneously to SD Card and external device. The A/D and D/A converters have a dynamic range of 98 dB, more than suitable for streaming and broadcast.
Power is provided by a USB C connection, physically separate from the second USB-C connection for data, with no On/Off switch. CEntrance recommends a power supply of at least 5 volts 2.1 amps or a power bank of at least 5000 mAh. When Portcaster is connected to a smartphone or tablet, it does not use their battery, whereas it does when connected to a computer. There is no problem keeping it constantly on. It does not include batteries because the space was taken up by the recorder on SD card, which is formatted by inserting the card and holding the Rec button while connecting the USB power cable. Different colors of the LED near the SD Card slot show the formatting status. By inserting an R4TIME.TXT file on the SD Card, the date and time of PortCaster can be updated. For cards larger than 32 GB (up to 256 GB), CEntrance requires that it be formatted directly to PortCaster.
Field Test
The English Channel is undoubtedly dedicated to vocal professionals only, given the purchase price, which is nevertheless lower and more affordable than the individual modules, and with the advantage of the case and accessories. The construction of the three modules is very robust and the potentiometers have just the right resistance to find the right point. Of course, each of the modules can have a life of its own: PortCaster is a very elegant solution for those who want to record vocals on digital DSLRs, for professional streaming (enough of those distorted or digital voices on YouTube...), for making podcasts or field recordings. It is small but very powerful: the preamplifiers were a big surprise in terms of detail, dynamic depth and naturalness. They are not asphyxiated or electronic. Their colour and performance are more studio preamplifier than portable audio interface. The limiter establishes itself as indispensable for two reasons: it is never artificial and allows plosive control with ease.
The two analogue modules are up to the task. SoapBox has everything needed for vocals. The preamplifier is delightful and improves even the performance of bad microphones. We had some fears about the dynamic section, but we changed our minds. The gate does what it has to do, useful in situations of background noise, and does not eat up transients. The compressor is very adaptable, with release times that always suit the voice. We never encountered any difficulties in using it and it ensured a smoother and fuller timbre. The de-esser is excellent: the result arrives in seconds and once set you can forget it exists. Never have I seen a preamp with such features in such a small space and still sound good!
BlackCab has quickly become indispensable for defining the character of the voice: you can find as many colours as you want, so as to offer for Voice Over different tones according to the work. While it becomes less indispensable in the case of post production, in streaming or radio it is an indispensable component to dress up the voice at its best. We appreciated the shelving filter on the treble that gave a bit more air, without ever overdoing it or making the voice artificial. The control between input and output levels is excellent and allows you to find the correct settings, thanks also to the pad if you overdo the eq.
Using PortCaster is super easy: there is no manual but a simple paper card that lists every function and connection. We immediately tried it with a bad Chinese condenser microphone, just to see what would happen, and the result was brilliant! We did not expect it to sound so good. Using the classic Shure SM 7B and also the small Neumann TLM 102, the preamplifiers were phenomenal in returning a clear, lively, dynamic, and non-artificial sound.
The HPF filter is perfect for vocals, and we were very surprised by the result of the limiters, which are not only necessary but indispensable to get a great take while keeping the plosives under control in a very natural way.
The metering LEDs are more than enough, and we never had a problem pushing a little harder on the limiter-protected preamps.
Basically you say goodbye forever to those bad distorted voices you hear in streaming or on Youtube: PortCaster ensures proper vocal handling even at exaggerated dynamic range. The preamps are quiet and delightful, in picking up vocals with some pleasant enhancement on the midrange that never borders on artificiality or equalization on the midrange. We would have no problem using them to pick up musical instruments as well.
The connection to the tablets and computer went smoothly without any hiccups. The iPads recognized it right away and maintained the connection without any problem. Ditto for computers. PortCaster can be used as a small, high-quality USB audio interface.
The idea of not using power from tablets and smartphones as a source is excellent: here we see the attention to those details that make a difference in mobile operation.
The headphone output was another surprise: the quality of the headphone amplifier is very good and above all it can support even difficult headphones, maintaining good dynamics and a balanced tonal response. It was a good choice to have a separate amplifier, because it allows you to work in any situation and with any headphones.
Being able to rely on the independent recorder is a guarantee for those who shoot footage on location and want to have a safe backup or, conversely, have no device for recording. To be applauded are the Minus Mix feature for connecting a smartphone and the Lo/Hi switch on the output that allows PortCaster to be connected to DSLRs, with a signal appearing to the camera as a microphone. Two excellent ideas that will be greatly appreciated by those who shoot directly in the field.
Conclusions
All in all, The English Channel far surpasses any portable solution in the world of streaming interfaces, which is still in the early stages of development and with ill-defined boundaries. CEntrance's choice is correct and professional in every respect: it has not reinvented the wheel, but has taken what has always been used in TV and radio studios, reworked it for mobility and streaming, and never compromised. The preamplifiers, dynamics section and equaliser remained analogue to provide the best possible sound, entrusting Portcaster with the set of functions needed in the 2020s, where there is no longer a boundary between Internet, radio, television, entertainment or professional journalism. The entire project responds to a demand for uncompromising audio quality combined with high flexibility.
PortCaster and complete bundle The English Channel were designed for the voice world, regardless of its purpose. It is a portable unit for Broadcast, Voice-Over, Podcasting, Radio or Video Journalists - working wherever they need to - when they are looking for its high-quality audio counterpart, for real-time streaming, whether mono or stereo, and as a high-quality front end for the audio input of digital SLRs.
The choice of its functions is based on this target audience, remembering that for musicians MixerFace is more suitable. That said, of PortCaster we loved the quality of the preamplifiers and the limiter, which is very effective and never intrusive, as well as the whole set of attentions that make this product unique.
The construction and audio quality, considering the purposes, are very good and professional, the portability (it fits in one hand!) is perfect for anyone looking for that extra gear in audio to give their voice the tonal and dynamic quality expected in professional audio. In fact, there is nothing like PortCaster when it comes to professional audio quality in a small space, at this price, for mobile broadcasting.
It deserves consideration for all those professionals who have made voice an art and a craft in the digital world, on the road with a backpack or sitting behind a desk.
