Allen & Heath Qu-16 – fully featured mixing console

We’ve recently invested in a number of 16 channel digital consoles which provide ultimate flexibility at the right price point.  These have been added to our rental stock, based in London and are proving very popular.  They are great little desks, easy to use and work well with our smaller sound systems.

 

FEATURE SUMMARY

  • 19” Rack Mountable
  • 16 Mono Mic/Line Inputs (TRS + XLR)
  • Recallable AnaLOGIQTM Preamps
  • 3 Stereo Inputs (TRS)
  • 12 Mix Outputs (XLR)
  • 7 Monitor Mixes (4 mono + 3 stereo)
  • 4 FX Engines
  • 2 dedicated FX Sends / Returns
  • 4 Mute Groups
  • 4 DCA Groups
  • AES Digital Out
  • 24×22 USB Audio Interface
  • dSNAKETM Remote Audio Port
  • 17 Motor Faders
  • 800×480 Touchscreen
  • 4 Soft Keys

QU-16 FEATURES

  • Trim, polarity, HPF, gate, insert, 4-band PEQ, compressor, delay on all Inputs
  • Insert, 4-band PEQ, 1/3 octave GEQ, compressor, delay on all Outputs
  • Automatic Mic Mixer
  • Channel Ducker on all Inputs
  • ProFactory Mic Presets
  • iLive FX Library
  • Built-in Signal Generator
  • RTA with Peak Band indication
  • Spectrogram to aid feedback elimination and room acoustics
  • Qu-Drive Direct Multitrack Recording / Playback on USB drives
  • DAW MIDI Control
  • Qu-Pad iPad App
  • Qu-You iPhone / Android personal monitoring app
  • Qu-Control customisable iOS app for simple wireless control
  • Compatible with ME Personal Mixing System
  • High contrast metallic finish controls, matching premium GLD Chrome series

 

Qu-16

New Venue – The Postal Museum

We are very excited and pleased to announce that we have been awarded preferred supplier status at London’s newest venue – The Postal Museum in Farringdon.

It is a light, bright and contemporary space that benefits from a private sunny courtyard and innovative living wall and is available to hire for up to 140 people, the space is perfect for cocktail receptions, summer parties and laid back BBQs.

Also available is the Mail Rail, the Royal Mail’s very own underground tube line, available for private dinners & parties, corporate events, fashion shows and filming/photography opportunities.  It is a captivating blank canvas space, set in a historical building with countless inspiring architectural features, including vaulted brick arches and railway influences and the option to actually ‘ride’ the Mail Ride during the event.

The spaces will be used as a fully working museum during the day and available for hire outside of these times.

Present Communications ltd values long term relationships with clients and venues and we often say that our best work takes place in familiar spaces.  We can’t wait to show you all that is possible with the two new spaces and working at this venue for many years to come.

Lambeth Palace – A birthday bash…

We recently spent the day with our friends at Lambeth Palace and Foodshow to throw a birthday bash for a large multi-national company.  1,000 staff were invited to enjoy the spectacular views and surroundings at Lambeth Palace which is the 3rd largest private garden in London,.  Their evening continued with culinary delights and fairground attractions before a short awards ceremony and a party into the evening.

Present Communications ltd provided audio, lighting and power equipment and technical support for the duration as well as a branded balloon archway and balloon drop to give that final touch.

“We have been a preferred supplier at Lambeth Palace for the last few years and enjoy making event technology work for clients who inevitably have high expectation given that they’ve chosen such an exceptional venue.  Foodshow make sure the food and service received is up to the same exquisite standard and we love seeing clients’ faces as they delve into their dinner”

CatchBox – Throwable Microphone – Audience Interaction and Engagement

We’ve always been big fans of audience interaction. Our audiences can often be online as well as in the room but today we want to focus on the room.

Event organisers, facilitators, and audience members want interaction. Often the best content is from the people watching the presentations. The CatchBox is a fun way to encourage conversation, break the ice, get people talking by throwing the CatchBox microphone and breaking the ice…

Present Communications are proud to be a partner with CatchBox. We are a hire stockist and a reseller and can therefore provide the best option for you and your event. We are even able to hire you the microphone but with your own branded casing, making it perfect for high profile events especially where there might be photographers or videographers.

Check out the website to see the options and the prices – http://eu.getcatchbox.com/

New Hire / Rental Stock – Nexo PA system

It’s always nice to get something nice and shiny in the warehouse and even better when we can get it out to clients and help make your events even better.

We’ve recently introduced a new speaker into the hire stock, it’s the Nexo PS8.  Nexo speakers are known within the industry for superb quality, they’re small, light weight and ‘punchy’.

We can’t wait for you to hear them!

Live Interpretation for Webcasting

The World is getting smaller, we are at the forefront of bringing people together using online technologies such as webcasting and video conferencing.  Technology is available for us to make events accessible to people wherever they might be at that specific time.  ‘Delegates’ (in the new sense of the word) are able to interact with each other on mobile devices or at their desks, even from an aeroplane (yes, we have done this).

There are a few obvious challenges to overcome.  The two big ones, time zones and languages.

The first is difficult to change, we can’t change time zones but we can be as flexible as possible with our event and we find ourselves now working on events at more peculiar times of the day.  If live interaction is not required, we can stagger the streaming in different countries.  Or perhaps two or three live events can be staggered throughout the day for the convenience of various audiences.

‘Languages’ are easier.  The stream, already going over the web can be interpreted live with questions and online interaction translated in real time.  This is becoming a relatively common way to stream and something that works really well for multi-lingual audiences.

In this photograph you see a remote location with real time video sent from the event location to an off-site venue which housed our interpreters who were them streamed live in the web.  It’s a big world, but it’s getting smaller.

 

 

Yamaha TF5 – 32 channel digital mixing console for hire in London

We are very excited about offering to our customers the latest Yamaha digital mixing console aimed at users who don’t need to masses of functionality and flexibility in more expensive desks but who still want a good quality desk that sounds good.  Future proof using DANTE and 32 channels in and out using USB2.0, this desk has plenty to offer most users…  See what Yamaha has to say below and have a look here for our prices

Yamaha has always made it a mission to stay in touch with the needs of sound engineers worldwide. The outcome is evident in the success of the recent CL and QL series digital mixing consoles, and the flagship RIVAGE PM10. The key to success has always been in supporting the user’s creativity. Creativity is most effective when unrestricted, and now Yamaha has created a new digital mixing console that gives the user’s intuition even freer rein. TouchFlow Operation™ introduced in the TF series consoles allows the user to respond to the music and artists on stage with unprecedented speed and freedom, taking live sound reinforcement to a new level of refinement. With the TouchFlow Operation interface optimized for touch panel control, experienced engineers as well as newcomers to the field will find it easier than ever to achieve the ideal mix. Recallable D-PRE preamplifiers support sound quality that will satisfy the most discerning professional ears, while advanced live recording features and seamless operation with high-performance I/O racks give these compact digital mixers capabilities that make them outstanding choices for a wide range of applications. Experience the intuitive control and creative freedom that a truly evolved digital console can provide.

TOUCHFLOW OPERATION™ – SMOOTH, NATURAL CONTROL FLOW

Yamaha digital consoles have always been designed with input from leading engineers worldwide to ensure that the most efficient, intuitive operation is achieved. The highly regarded Selected Channel and Centralogic™ interfaces attest to the success of that approach. The TF series combines Yamaha know-how with new input from the field and the latest touch-screen technology to deliver an evolved experience in console operation. Smooth setup and operation, practical presets and scenes, refined design, and software applications that integrate seamlessly with the entire system: these elements comprise TouchFlow Operation, a new concept in console interfaces that offers unprecedented comfort and convenience in small consoles, for a wide range of users and applications.

In developing the TF series Yamaha engineers built from their existing base of acclaimed high-end mixer interfaces, adding intuitive control in an interface optimized for the type of touch panel control that has become a familiar feature in a wide range of applications. Allowing most operations to be carried out via the touch panel alone, the innovative TF series interface will quickly become second nature to a broad spectrum of users. Whether you have experience with Yamaha digital consoles, work with other digital consoles, operate analog consoles, or have never operated a mixer before, TF consoles will lead you to the desired results quickly and effortlessly through a smooth, efficient workflow. The availability of physical controls surrounding the touch panel further enhances control versatility and precision.

TOUCH OPERATION FOR INTIMATE CONTROL

Refined for the smoothest possible operation via touch-panel control, the TF user interface offers a smooth workflow that can be an advantage in any mixing situation. The display content has been specifically designed for easy, direct accessibility, with a layout that promotes the most natural, efficient mixing. Touch panel operation is as easy as shaping the sound with your fingertips.
TOUCH & TURN KNOB OFFERS EXTRA CONTROL PRECISION
When you need extra precision for a fine EQ or other adjustment, the physical Touch & Turn knob is always available right beside the touch panel. There are also four User Defined Knobs below the panel that can be assigned to control compressor threshold, EQ gain, or other parameters you need fast, direct access to while mixing. The knobs always affect the currently selected channel.

TRADITIONAL OVERVIEW AND SELECTED CHANNEL INTERFACES
Like the CL series consoles, operation is based around Overview and Selected Channel windows. The overview display shows the parameters for eight channels at a time, while the Touch & Turn knob provides direct access to gain, 1-knob EQ™, 1-knob COMP™, gate threshold, effect send level, pan, and other parameters. Touch the highlighted parameter a second time to switch to the Selected Channel display when you need access to detailed parameters for finer control.

Effective gain, compressor, and EQ setup requires a considerable degree of skill and experience. Even veteran engineers need to spend time on these important basic settings. In addition to their intuitive user interfaces, TF consoles include a number of features that contribute to faster, smoother setup of these essential parameters.

1-KNOB COMP™ & 1-KNOB EQ™: ONE KNOB TO DIAL IN THE IDEAL SOUND
An experienced engineer can do a lot with a compressor: bring a guitar to life, add punch to bass, tighten up a snare, and make vocals ride clearly on the mix. The 1-knob COMP can do all of this quickly and easily, without the need to juggle multiple parameters to achieve the desired effect. Originally introduced in Yamaha analog mixers, the 1-knob COMP quickly became a popular and valued feature. It has now been further refined in a digital version that adds new setup ease and efficiency to the TF consoles.The same concept has been applied in a new 1-knob EQ feature that provides notably improved speed and smooth operation. 1-knob EQ has been painstakingly fine-tuned by Yamaha R&D staff in cooperation with distinguished sound engineers, to ensure that you can achieve outstanding results with minimum effort in the shortest possible time. A Vocal Mode makes it easier than ever to achieve a clear, well defined vocal sound, while an Intensity Mode offers 1-knob “intensity” control over EQ curves you either select from the presets or create from scratch.But there’s more: the 1-knob COMP and 1-knob EQ are provided on the output channels too, so you can quickly achieve overall output compression or EQ that ideally matches the room and audience size. The output 1-knob EQ has a Loudness Mode in place of the Vocal Mode, effectively increasing the sound pressure level while maintaining optimum sound as you rotate the knob.Both the 1-knob COMP and 1-knob EQ provide quick access to the full compressor and EQ displays, so you can fine tune settings as required.

GAINFINDER™ SUPPORTS PRECISION GAIN SETUP
Gain is the first adjustment the input signal sees, and the way it is set up influences how subsequent parameters will affect the signal. Yamaha has developed a way to make fast, accurate setup of this important basic parameter easier than ever. The new GainFinder feature facilitates optimum gain setup for individual input signals so that ideal overall operation and signal quality is achieved. The user only has to set channel gain so that the central green indicator in the level meter remains lit for the longest possible time. Of course the level meters also perform their traditional function, so standard gain setup procedure can be followed if preferred.

The familiar Yamaha scene memory that stores mix settings for instant recall when needed is included as always. There’s also a range of channel presets that have been created in cooperation with leading microphone manufacturers and eminent sound engineers, providing starting points that take you a long way towards achieving great sound.The channel presets cover parameters such as HA gain, EQ, dynamics, and much more, right down to details like channel name and color. Less time needs to be spent on basic setup so that more time is available for refining the mix and communicating with the performers.
QUICKPRO PRESETS™ PROVIDE INSTANT ACCESS TO PRO SOUND SETUPS
Working with microphone manufacturers such as Audio-Technica, Sennheiser and Shure as well as respected engineers, and evaluating a large number of microphones, musical instruments, speaker systems, and in-ear monitors, the Yamaha R&D team focused on creating a range of shortcuts to great sound that would be effective in a wide variety of live-sound situations. Armed with these practical presets even the novice engineer can get very close to the ideal sound, while experienced engineers will appreciate the significant time savings they can provide starting points for further adjustments.The QuickPro Presets can be searched by instrument type and recalled quickly and easily. The presets include HA gain, EQ, Comp and other settings, right down to the channel name and color. The 1-knob EQ and 1-knob COMP can be used with QuickPro Presets, providing a super streamlined way to tweak the sound.The output channel preset library includes parameter sets optimized for Yamaha powered speakers, with several variations to match different environments and room sizes. Presets are provided for in-ear monitors too. All of these can be used as is when time is tight, but they are also great starting points for manual fine tuning. Setups created from the presets or from scratch can be saved as additional presets too.

COMMENT FROM AUDIO-TECHNICA CORPORATION
“Each Audio-Technica microphone is painstakingly designed to give a truly accurate reproduction within the application it has been selected for. We strive to provide the best possible tools allowing the user to realise the expression of their work. Collaborating closely with the TF engineers on the instrument specific presets means that we can be sure our microphones deliver their best performance, while leaving the user free to focus on the creativity and character of the production.”

COMMENT FROM SENNHEISER
“The presets in the Yamaha TF series digital mixers provide users with an accurate indication of how to set the EQ for a wide variety of instrument/microphone combinations. These preset functions give the sound technician a solid basis to start from. All that is needed is to adapt the EQ-ing to the specific room and the instruments.”

COMMENT FROM SHURE
“We’re thrilled to be offering QuickPro presets of our most popular SM, Beta, KSM and PG Alta microphones in the new TF mixer. When you combine Shure’s 90 years of microphone experience with the versatile new TF digital mixer and exceptional Yamaha speakers, these presets allow engineers at any level of experience to leverage our combined technical expertise for quick, simple and effective sound checks and performances that sound amazing. Engineers can focus on mixing great quality audio instead of chasing problems. It’s an incredibly powerful solution.”

TWO SCENE MEMORY BANKS
The scene memory features banks A and B, each capable of holding up to 100 scenes.That’s a total of 200 scenes that can be set up and instantly recalled whenever needed.A number of scenes are pre-programmed to give users a head start: scenes with the 1-knob COMP and 1-knob EQ controls engaged for the easiest possible operation, and scenes with the 1-knob features disabled for experienced engineers who might want to follow an established procedure. The banks are great for organizing different types of scenes: one for scenes categorized by music type, and the other by event type, for example.

The TF series hardware is packed with features that contribute to superior operability and convenience. Faders, knobs, and buttons with outstanding fit and feel work seamlessly with state-of-the-art display technology, including high-visibility channel name and color displays. The touch panel itself offers an ideal blend of comprehensive visual feedback and fast response.The physical layout of these components brings everything together in a system that offers surprisingly efficient workflow.
PANEL LAYOUT MAXIMIZES WORKFLOW EFFICIENCY
Careful analysis of the workflows favored by a large number of engineers has led to a highly efficient panel layout. Rather than simply providing a long list of advanced features, the TF consoles present meaningful features in the most logical and accessible way through an overall design that maximizes visibility and operability.
COMPREHENSIVE FADER BANK SECTION
Two INPUT banks and one OUTPUT bank are provided, and the GROUP bank can be selected by pressing both the INPUT bank buttons simultaneously. The GROUP bank allows the levels of multiple channels to be controlled from a single DCA fader. There’s also a CUSTOM fader bank where you can assign any input, output, and DCA group to any fader.

DCA ROLL-OUT ENHANCES GROUP CONTROL
When the GROUP fader bank is selected, all faders other than DCA masters 1 through 8 function as Roll-out faders. Selecting one of the DCA groups instantly “rolls out” the input channels belonging to that group to the Roll-out faders. This useful function makes it easy to adjust the level and other parameters of individual channels while using the eight DCA faders for overall mixing.

CHANNEL NAME AND COLOR
A display panel located above each channel fader shows the assigned channel name or ID, the port name, and the current fader setting. Phantom power status as well as gate and comp operation can also be displayed. A color bar that shows the assigned channel color makes visual navigation a breeze, and prevents confusion when fader banks are changed or scenes are recalled.

FADERS PROVIDE A CLEAR VIEW OF ALL INPUTS
The TF5 has 33 motor faders, the TF3 has 25, and the TF1 has 17.All rear-panel inputs have individual faders so their status can be verified at a glance and they can be directly and immediately accessed for control.

SENDS ON FADER SECTION
The SENDS ON FADER buttons instantly bring the specified AUX or FX bus levels up on the faders for easy verification and adjustment. When a SENDS ON FADER button is engaged the MASTER fader acts as the master for the corresponding bus, so AUX levels can be checked and controlled without having to switch fader banks.

ADVANCED DESIGN PROMOTES SMOOTH, COMFORTABLE OPERATION
The upper section of the panel is designed to double as a rest for an iPad, set list, score, memos, and/or other small items. The panel consists of three angled sections that give the operator maximum visibility and access.

OTHER FEATURES FOR EFFICIENT WORKFLOW
– USER DEFINED KNOBS section: Frequently used parameters such as compressor threshold and EQ gain, for example, can be assigned for direct, instant access when needed.- USER DEFINED KEYS section: Assign mixer settings that you use often to these six buttons for instant access, such as direct one-touch recall of specified scenes.- MUTE section: Multiple inputs or effects can be muted with a single operation.- FX section: A dedicated channel offers easy effect ON/OFF switching, cue monitor ON/OFF switching, level adjustment, and effect parameter editing.- ST IN section: In addition to allowing digital playback from an iPad or iPhone or recording/playback with a USB device, you have fingertip control of BGM playback and other audio files.

Separate software applications that allow wireless mixing, personal monitor mixing, or offline setup of digital live mixing consoles have become fairly common.The TF series goes a step further with three dedicated apps – TF Editor, TF StageMix, and MonitorMix – that feature user interfaces that seamlessly extend the console’s own on any device.
TF EDITOR FACILITATES OFFLINE EDITING PLUS SHOWTIME CONTROL
The TF Editor application for Windows and Mac computers provides a complete interface for offline editing and setup of TF consoles, with scene and preset management capabilities plus convenient keyboard entry of channel names.In addition to being able to set up the console offline at any convenient location and time, the TF Editor can be used online at the same time as the TF StageMix and MonitorMix applications. A Windows 8 PC with a multi-touch screen can use the same gestures as on the console itself. And if using Wi-Fi, a PC can function as a convenient remote-mixing device. Up to three devices running TF Editor or StageMix can be connected at the same time.

TF STAGEMIX™ FOR WIRELESS MIXING
TF StageMix is an iPad application that provides wireless control of TF series consoles, allowing remote mixing from audience seating, in front of floor monitors, or any other listening position. It can also be used at the console as an extension of the console’s own interface. The TF StageMix interface is designed for similar operation and flow to the console display, making it easier than ever to refine the mix from any location.

PERSONAL MONITORING WITH MONITORMIX
The MonitorMix application for the TF Series allows individual wireless AUX mixing from up to 10 iPhone, iPad or iPod touch devices simultaneously. Each performer can have convenient control over the AUX buses assigned to them, without having to deal with complex settings or parameters. They can also create personal Group settings for even easier adjustment: all levels on just one fader, for example. Since up to three devices running TF Editor or StageMix and up to 10 devices running MonitorMix can be connected at the same time, even large bands can have the personal control they need, reducing demands on the sound engineer.

A NATURAL SOUND FOUNDATION WITH EXTRA CREATIVE FREEDOM

Faithful reproduction of the on-stage sound is the foundation, then creativity can take over.Yamaha’s unswerving approach to live sound reinforcement is alive and well in the TF series.The input stage of any console has a notable effect on its sonic character.The TF consoles feature acclaimed D-PRE™ microphone preamplifiers that not only deliver outstanding quality, but are recallable as well. Circuitry and individual components have been reassessed and redesigned where necessary to achieve extraordinarily pure, natural sound. That solid sonic foundation is backed up by an updated selection of high-performance processors and effects. Input and output channel processors such as EQ, gates, and compressors are complemented by eight processors that provide a broad spectrum of creative capabilities.
RECALLABLE D-PRE™ MICROPHONE PREAMPLIFIERS
The TF series consoles feature new recallable versions of Yamaha’s acclaimed D-PRE microphone preamplifier. The preamplifiers, or head amplifiers in any console play a significant role in defining the sound of the final mix, so Yamaha engineers spared no effort in developing and refining the D-PRE design to ensure that every nuance and subtlety of the original signal is effectively captured. The circuit is based on a discrete inverted Darlington pair configuration that achieves clean, precise amplification with consistently low noise and distortion at all signal levels. While some microphone preamps are built specifically to impart a unique character of their own, the D-PRE preamplifier has been painstakingly designed with a flat, wide frequency response that retains the tone and nuance of the original sound so that the essence of the performer’s art is captured intact.

POWERFUL PROCESSORS AND EFFECTS
In addition to EQ and two dynamics processors on each channel, the TF consoles offer eight powerful processors for wide-ranging sonic control. The globally accessible FX 1 and 2 feature the same type of SPX processors that have become standards in recording and live sound applications, offering 17 programs ranging from reverb and delay through modulation effects such as flanger and chorus to 3-band multiband compression. The panel EDIT key opens the effect parameter display where detailed parameters such as reverb time and delay feedback can be adjusted as required.The remaining six processors are available in the AUX 9/10~19/20 master channels.All effects other than reverb are provided.* Multiband compression is ideal for in-ear monitor level control, delay can be used for speaker alignment, and much more. And since these AUX buses can be sent to the main stereo bus, the effects can be used to supplement the available input channel processing when FX 1 and 2 aren’t quite enough.The AUX 1~8 buses and main output channels include the same 4-band parametric EQ as provided on the input channels, plus 31-band Flex12 GEQ. Both types of EQ are invaluable for optimizing speaker response and eliminating feedback.* Reverb is available for AUX 9/10 and 11/12.

A VERSATILE LIVE RECORDING AND PLAYBACK SOLUTION FOR ANY APPLICATION

Live recording capability is becoming increasingly important in live sound systems. From simple 2-track recording and playback using a USB storage device* to all-out multitrack recording with a computer based DAW (Digital Audio Workstation), the TF series is ready to roll. TF consoles come supplied with Steinberg’s Cubase AI DAW application, providing an easy way to simultaneously record up to 16 tracks to a computer connected to the console via USB 2.0.For more complex recording requirements an optional DAW such as Steinberg’s Nuendo Live application allows up to 34 tracks to be recorded simultaneously.MP3 and WAV files can be played back from USB storage devices, and audio from an iPhone or iPad can be played back via a direct digital connection.When playing back from a DAW, analog input or DAW input can be individually selected for each channel so that pre-recorded material can be mixed with live input for virtual sound checks or rehearsals.Of course BGM and sound effects can be played back too.*Please refer to www.yamahaproaudio.com for compatible hard disks.

Sound, Light and Video – the importance of thinking it through…

We’ve all been there.  It mostly works but it just isn’t good enough.  We’re watching TV or playing a computer game.

So imagine you’re sitting on an aeroplane, you’re watching an in-flight movie.  The quality is really bad.  It gets worse, it becomes so annoying that you have to turn it off.

Now think about that.  What was so annoying about it?

Imagine the video is all wavy and you struggle to make out the picture but the audio is fine.  Now imagine the audio is so bad you can’t hear anything but the picture is fine.  Which one are you more likely to be able to take.

When we watch a video, it’s the audio we need as much as, maybe even more than the video.  We can live with a pixelated image although we might rather it was perfect.  But bad audio will give headaches and cause us to be constantly struggling to hear.

So make sure you use a supplier who understands not just the IT aspects but also the video and audio aspects of the project.  Make sure you use Present Communications ltd.

Balanced audio?

I work in so many places and with so many people where the concept of balanced audio (and the problems associated with unbalanced audio) haven’t quite hit home. But what is the difference?  Well, despite what you might have heard, it’s really quite simple.

Balanced-Audio2

We ‘balance’ the signal.  Essentially, the signal in the cable is carried down two wires, instead of one.  Each one is affected differently by any interference and can be compared later to find where the interference is and eliminate it.  That’s the easy explanation and not entirely accurate…

Ok, now if you get that, we can explain it properly.  How can you compare two signals and eliminate any interference in a simple analogue circuit?  Firstly, take the signal and create an identical but opposite signal.  So that is ‘phase inverted’.  These two signals are carried down two separate wires, the hot and the cold and they share a common ground giving a balanced signal 3 pins instead of the 2 pins used by an unbalanced signal.  So far, simple.

 

 

Now we can imagine that every interference ‘spike’ is a separate problem and deal with them individually.  Interference will cause an alteration in the sin wave as you can see in the diagram on the left and that alteration will be identical on both the hot and the cold wires.

 

Now if we just reverse the polarity of one of those signals again, both signals will look the same except for the interference spike which will be exactly opposite on both pins.  Now if those signals are joined back together to create a single signal, the interference will be completed cancelled out.

 

There are a number of other things that help such as impedance matching and shielded cables and perhaps we’ll look at those next…