Getting the most Level out of your system – Beginners Guide to Graphic EQ

So you have a sound rig, and every time you push the volume on the desk, an annoying whistle of feedback scuppers your day.

This issue can be made even worse when a microphone is in front of a speaker, or pointed towards it. You may think that theres nothing that can be done to fix the issue, and either brace yourself for glaring feedback every so often, or keep the level lower in the room and often face complaints from the audience.

In order to fix the issue, you are unfortunately going to need to recreate the feedback.

If you have an Analogue Sound desk, you will probably need to purchase a Stereo 31 Band Graphic EQ, (maybe more if you have Matrix sends or wedges). If you have a digital desk there will be Graphic EQ’s built in, its just a case of finding them in the menu, and inserting them over the relevant outputs. For this blog we’ll assume only a graphic over Left & Right, and that its a Analogue desk.

Some good models are DBX 231, BSS 966, Klark Teknik SQ1.

There are two main ways to add a Graphic EQ into your Analogue system, you can either Insert it over the offending channel or output, or simply add it in line after the desk.

Insert

Most desks have the option to insert, like this Zed R16.

ZED-R16 Insert

Looking more closely at the input and output sections, we can see that Input wise, there is XLR and Jack in, and then an Insert for a Compressor, Gate or Graphic EQ (Red Box).

This can be exceptionally useful if its only one troublesome mic, like a lectern in front of the speakers, and needs quite a drastic EQ, that would make the rest of the system sound terrible.

ZED-R16 Insert copy

And Below the XLR outputs, there is a separate 2 track output, and then the Inserts for Left & Right (Yellow Box). This can be used to insert a graphic, external compressor, vintage EQ, limiter.

EQA231 rear

The back of each Graphic is very similar, they need power, and then have XLR In & Out and Jack In & Out for each channel. Some have extra multipin Ins/Outs to save on cable.

To Insert one channel of Graphic, you would need a stereo Jack to two mono Jacks, or Stereo Jack to 2 XLR’s. If they are wired correctly the Red should be the output of the Graphic back into the desk, and the Grey/White/Black depending on make, would be the signal from the desk into the Graphic. Its fairly simple to workout if its wrong and just requires repatching the graphic.

insert_diagram Stereo to mono jacks

In Line

This is the simplest way to add a graphic into your chain. Take the XLR L&R Outputs of the desk and patch them into the graphic, then take the outputs of the graphic back into the next item in the chain (Amprack / Speaker Processor / Multicore).

There.. I said that was simple.

Controls

For each of the specially selected frequencies on a graphic EQ, there is a fader that can either give +/-6dB, +/-12dB or +/-15dB of gain to the selected frequency.

Apart from 31 faders for each channel of graphic, there are a few controls to get your head around. Some of the physically smaller rack units limit the faders to +/-6dB of gain, and then give you an overall switch to change to +/-12dB of gain – essentially doubling the range of each frequencies gain reduction.

Gain, how much has the graphic affected the overall sound from before it was patched in to being fully set. Try and set it up at the same level as the unit bypassed.

BSS 31 Graphic

Low Cut Button / HPF Knob, this allows you to reduce the low end going to the amps / speakers. Helpful if your not using a crossover, or only have tops. Meaning that low end won’t be going to a small speaker thats dealing with the upper frequencies.

DBx 31 band graphic 231

Bypass is a useful one, checking that when you have removed the offending frequencies, you haven’t removed too much of the sound. Sometimes when you bypass the Graphic the sound is better, if so start again!

Removing Feedback

As I said above, in order to remove feedback, you have to create it. When you turn up the mic to the point of feedback, and then find that particular ringing frequency, and pull it down on the graphic. One easy way for beginners to learn what frequencies are feeding back is to use an RTA app on your phone.

RTA 1RTA 2

I use “n-Track Tuner” which is a nice dark display for dark stages. There is a free version, but I use the Pro app, which has several other features and display options. As you can see, it allows you to tell where problem frequencies are and allows you to sweep your finger along the graph to see the exact frequency.

If you want to improve your ears, I can recommend using these apps (link below) on your computer. They are designed as a little game for you to workout which frequency is the tone emitted, and allowing you to learn what different frequencies sound like.

Feedback trainer – Mac & PC

SQ1-graphic-front

I hope this was helpful. Leave a comment below about your experiences.

Dan

What is a good distance to speak into a lectern mic?

This is a question that I get asked all too often.

Ideally, you should be standing upright in a comfortable position. With Lectern mics, its best if you don’t wander around, and ideally keep facing forward whilst speaking. The more movement and head turning there is. The less likely you are to have clean audio.

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Obviously every mic is different, and some may require being closer to your mouth than others. As a general rule, about 25-35cms (~1ft) is ideal.

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More favourite songs.

Carrying on from where my last music blog left off, I have a new selection of tunes for you to check out!

Fort Minor – In Stereo

Ed Sheeran – Thinking Out Loud

Josh Devine & Ollie Green – Jailhouse

Michael Jackson – Beat It

Alexander Stewart – Human

Dave Matthews Band – Ants Marching

Gary Go – So So

The Lonely Island –Hugs

Submotion Orchestra – In Gold

P.O.D. – Teachers

Muse – Butterflies & Hurricanes

Queen – Another One Bites the Dust

Great White Whale – XOXOXO

Submotion Orchestra – Red Dress

Audacious – Louder

There you are. A pretty wide range of genres and years released. Go and check out these awesome Bands/Artists. Comment below with some of your favourites.

Current Favourite Songs

Some of these artists and songs are new to my collection, while others are old favourites! I do quite a bit of Website maintenance, and other office related work. I’ve very thankful for having these KRK’s in my arsenal, allowing a ‘true’ sound. These songs are the ones which get me through the slog of emails, and feature heavily in my playlists on the road.

Toto – Pamela

Dorje – Catalyst

Gregory Porter – Magic Cap

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What’s in the Peli?

I carry a pretty comprehensive toolcase with me to most gigs. It has grown significantly over the last few years. When I started out, just carrying Lx tape, Sharpie, Leatherman and Torch shoved in a rucksack got me by. Nowadays, there is a higher expectation on my to have everything and make the gig work, even if broken equipment / cables have been sent out! This list of stuff rarely changes, and whether i’m travelling as a Band Engineer, Sent off with a van to a function gig, or putting up PA Systems and 60″ Tv’s at Corporate Conferences / Exhibitions as an AV Tech, all the things have been used on one gig or another.

IMG_3252IMG_3250 Continue reading

Beginners Guide – Cables

Cables! These connect the world together – literally! Your setup, be it home studio or Stadium PA with huge line arrays, is only as good as your cabling. You can have the best equipment in the world, but if your cables connecting them together are broken or damaged, then the resulting sound quality will be affected.

This should be a relatively short blog post, as I only have a few headings to cover in this section. I will only be looking at Audio Cables, however some for them uses include video and lighting.

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Beginners Guide – Microphones

Being the Second part of my Beginners Guide, we shall focus at the start of the Signal Chain, and later posts will focus on later items.

As stated in the previous post, Microphones and Speakers are both Transducers, converting energy from one form to another. Microphone transfer Kinetic (movement energy) to Electrical energy, where as Speakers transfer Electrical energy back into Kinetic energy.

Something to note is that all microphones do not all work in all directions. Some may be best to pick up sound from in front and behind equally, while others reject sound from the rear. he way mics are split up into these categories is by their Polar Patterns (directionality). Continue reading

Music worth listening to!

Many many songs have been written, many genre’s.. over a large amount of time.

As a Sound Engineer / Producer, I get to listen to a wide variety of music, and this blog post will concentrate on some killer bands, songs and hopefully educate some of you in lesser know artists.

I don’t really like defining an artist as EDM, or Jazz, but it seems to help people understand the rough type of music it is. If I had my way, there would only be two Genre’s of music, Good & Bad!

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Wedges vs InEars

Note to you that this is a long post, with many sections. And while I will aim to cover all the options and keep impartial it may not happen. Also I am writing this post more from my musician side rather than a technical perspective, although they naturally collide, (apologies if you wanted to know whether to invert the polarity of your Lead Vocals cause they can’t hear enough low end – I may cover that in another post).

People like to hear themselves. And I would say that Musicians enjoy knowing that they are singing/playing in tune/time!

 Okay maybe not enjoy.. Maybe require!

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iPad Apps for Live Sound – Part 1 – Yamaha Stage Mix

I have had quite a bit of experience with the various medium sized digital consoles. and as part of how I work, I use the iPad apps to either run around the room, or set stage levels.

I thought that I could leave you with a summary of my favourite features of the apps and leave you to comment on your own.

Here is the first part of the series…

Yamaha’s StageMix – LS9 / M7CL / QL Series/ CL Series Continue reading