New Blog

[DanOwens]

Yes, Shep, it has taken long enough but here is my blog post about multiple signal paths.

All you DnB/Dubstep players take note!

[url="http://mrdfowens.tumblr.com/post/6625226238/multiple-signal-paths-parallel-effects"]HERE[/url]

Any comments? I can add things if I've missed stuff out or write it into another post.

Dan

[DanOwens]

In fact, here's the text:

[indent]This is, once again, the 10th time I have tried to write this article. My biggest problem with this whole blogging malarkey is that it is meant to be about the philosophy of sound design through bass guitar technology and the application of that philosophy. The thing is, that can become very long and very boring and regularly does; as such I go through the process of writing and deleting over and over again, get bored of it and sack it off.

This time, though, I’m going to finish!!

[b]Introduction[/b]

This article is about the use of multiple signal paths. So-called ‘Bi-Amping’ (the use of two amplifiers at the same time) is an example of this, but I want to focus on a more effects-based approach.

The idea is that you take a single sound source (ie: your guitar) and rather than having one signal (guitar > pedal > amp), you split the signal somewhere in the chain and eventually sum them together towards the end.

A distortion pedal with a blend control is effectively utilizing multiple signal paths as within the pedal the signal gets split, one signal gets effected whilst the other doesn’t, then the signals are summed. The philosophy of this distortion pedal is the same as a more complicated setup in that the user wants to create a sound that is more sonically rich than one can achieve with a single signal path.

As I’ve said in a previous blog, electronic music layers numerous sounds to create a rich, undulating (I like that word) sonic texture that is continually moving and changing. I must reiterate that trying to carbon-copy sounds on records is doing yourself an injustice. If we are going to engage in this foray into acoustically-created electronic music, then we have the opportunity as pioneers to shape the way our music is formed in a new and unique way.

That said, using familiar sounds as our starting point is useful, and utilizing some simple philosophies and technologies to achieve this is a rewarding experience.

Splitting and Summing

Splitting and summing forms the core philosophy of the implementation of multiple signal paths and is also the root of all problems in this field.

I spent a long time experimenting with a variety of setups and I’ll briefly describe a few:

I started with the notion of a rich sub with a chorused distorted lead on top. I didn’t want to spend anything so I used a Boss TU2 and a Line 6 DL4 that I already had. The TU2 has both muted and bypassed outputs which can be used at the same time. This means the pedal splits your signal: Yey!

As for summing, the Line 6 DL4 has both looper and delay functionalities. The pedal is designed to be used with both guitars and keyboards and as such has both stereo inputs and outputs. The thing is, the looper doesn’t have stereo functionality so when in looper mode, the pedal sums the stereo inputs to the mono (Left) output. That’s right: Summing!

So thinking about the TU2 and DL4 as functional tools rather than tuning or delay pedals opens up opportunities and creative possibilities that we didn’t know about and this is the attitude and philosophy that we must pursue to be the pioneers we perceive ourselves to be.

Using the TU2 as a signal splitter and using two amps as signal destinations is another implementation of the multiple signal path concept that I use on a fairly regular basis with a variety of electronic/art-rock trios, using one signal path with my bass board (OC2 > Mammoth > CEB3 > LPF > VT2 > DL4) and sending the second signal path to a Line 6 M13, pitching the signal up by an octave, EQing out the bass and adding a variety of modulation and synth effects then sending it to a guitar amp. This makes my bass sound HUGE, especially when using the OC2 with the bass signal as I effectively multiply my sound over 4 octaves!

All these uses can sound a bit complicated, and if you want to simplify things the Boss LS2 is your friend. A second-hand Boss LS2 is an amazing tool to have in your arsenal and can be found for around £40. The far right rotary controller on the LS2 changes the function of the pedal and for the purposes of multiple signal paths, we will use the setting ‘A+B Mix’.

This setting splits and sums your signal, allowing you to use one source (guitar) and one destination (amp) with two separate and blendable signal paths. I cannot recommend this pedal enough.

[b]Problems[/b]

If the LS2 is your friend, phasing is your worst enemy. If you’ve ever tuned your bass with harmonics, you can use the pulsing, phasing sound to check whether you’re in tune. This is one of the few times when phasing is not a massive problem.

I’ll apologise to anyone who understands the real complexity of phasing but I’ll briefly describe what it is and why it is a problem. Imagine a speaker moving back and forwards to create sound. Phasing is caused when two identical or similar signals move in opposite directions and effectively cancel each other out. This means your sound will appear weak and hollow; the complete antithesis of the reason why we’ve chosen this.

Phasing can be a problem if you’re using multiple signal paths and using delay or if the multiple paths sound too similar (hence my TU2 / M13 implementation using very different sounds). If you’re sounds are too similar, then you’re also going to compromise the effectiveness of the rich and changing sounds you’re trying to create.

[b]Implementation[/b]

There are lots of different ways to use this concept of multiple signal paths:

Using the paths across different pitch ranges can form a rich harmonic texture, filling out the sound and allowing other band members space for them to add their own sounds.

Using waveform generators can avoid some phasing issues as they replace the signal with a new sound. They can also recreate a very synth-like sound. I’ve used a Freqbox and SYB5 in the past but I’m currently using the M13 and Mammoth to this end.

Using modulation in one of the signal paths can create a modulating and shifting texture that can retain interest over long, held notes. Tremolos, flangers, phasers and choruses work really well. I use an Adrenalinn 2.

By having sounds that contrast in their attack and decay and don’t overlap, you can create the illusion of different sounds weaving in and out of each other. The EHX Bass Microsynth has an ‘Attack’ slider, which can cause the notes to swell in over time. By combining this with a LFO on the other signal path, you can create two independent sounds that’ll intertwine and create a powerful sound.

[b]Conclusion[/b]

When I started using multiple signal paths, I had a variety of problems. The thing is, I didn’t care because I could create rich and interesting sounds and by experimenting I’ve created a way to make sounds that are HUGE.

I currently use two LS2s and two amps to create this sound but I’ve had custom pedals built and have used a combination of the setups above. The thing is, when you start on this path it can change your approach to playing and thinking about sounds. Experiment and enjoy it!
[/indent]

[escholl]

A really good way to play around with this is to set up a channel in your choice of DAW, and then run a few sends out to other channels/busses with different effects on each. Parallel signal processing is amazing.

I've been developing a hardware solution to this, letting me split my signal up to four ways. In addition to summing, it also has phase controls, allowing me to change the phase of each returned signal till I get the best sound. Won't be done for at least another year I'd imagine, but will be sure to post the results when I'm done...err, eventually.

[thumbo]

In 10 years of owning a TU2 it never occurred to me that it could be used as a signal splitter. That's quite a handy thing to bare in mind when putting together a pedal board

[pantherairsoft]

About bloody time!!!



A very good read & some useful stuff. I actually use very little signal splitting or blending... I do use an LS-2 to have 2 over lapping sounds on a couple of tracks. I aim to spend some real time on splitting the signal chain more so the Sub runs all the time and effect the higher frequencies - bit this will have to wait until I get some time off.

When I finally go further down this route I'll prob give you a shout over some advice, Dan.

Shep

[DanOwens]

Shep > I'm always lurking

Thumbo > That is exactly the reason I write this stuff. Thanks so much for that comment! I feel vindicated!

Escholl > Umph (Mammoth Audio) custom built me a box with 5 mutable send/returns but there are an unbelievable amount of things to take into consideration using that many buffers/volume controls/sends/returns. In the end it costed him a lot more than I paid and we just gave up. I'd be interested to see your solution.

What's next? I'm thinking of a bit of easy theory (I am a music teacher after all). Any requests?

[pantherairsoft]

Theory seems an odd move for the 'Modular Synth' themed blurb.

What about...
Advantages/disadvantages of buffers in signal chain
EQ & Frequency exploration
Application of software (ableton etc) in live performance
Working with a Synth player (and not stepping on each others toes)

Shep

[DanOwens]

I like the last one for sure. I'll have a think. Thanks as always Shep.

[pantherairsoft]

My pleasure...

I'd be interested in your stance and thoughts on the last point. I'm in the lily position where I kinda' am the synth player. As it's just me and a drummer, ad long as it's tight & in time, then nothing is 'wrong'. Nonsuch thing as a wrong note if there's no one else to pitch to or harmonise with

We're looking for collaborators for our next EP (have a few vocalists on board already), so I'd be interested in seeing how you guys work around each other in preparation for doing so myself...

Shep

[escholl]

[quote name='DanOwens' post='1273231' date='Jun 17 2011, 09:30 PM']Escholl > Umph (Mammoth Audio) custom built me a box with 5 mutable send/returns but there are an unbelievable amount of things to take into consideration using that many buffers/volume controls/sends/returns. In the end it costed him a lot more than I paid and we just gave up. I'd be interested to see your solution.[/quote]
Really? I found it pretty straightforward actually, basically a four channel line mixer. Send/Return Levels, and a footswitch engage for each channel. Only tricky bit was the phase adjustment, but a bit of research sorted that out. Mind you, my design is a little more complicated than just a mixer, as it also includes a preamp, a DI, and several other things. What sort of issues did you encounter?

I've also got a (much simpler) send/return box, which either sends full range to both or filters the high to the send/return, and low to the straight signal.

[cheddatom]

I've been recording through my board for my old band. I've never had tones this good, and will no doubt post some samples at some point. Anyway, I split the signal to record a totally dry track, and one track through my board. The board is then split in 2. I use the dry track to provide all the very bottom end and the board for everything else. I'm not that into "electronica" but was playing last night, using my left hand to play simple bass lines, and using tapping and effects with my right hand to try and do some melodies - it was ace! I'd love to have a go at Shep's sort of line-up.

Anyway, yeh, parallel processing is a must for most good bass tones - not just electronic.

[xgsjx]

Great blog Dan.
I've been dipping my toes into channel splitting using the bass murf's stereo outs & putting it on static.
The good thing about this is that it sends different frequencies to each channel, so less chance of phase issues.
I need some more fx (such as an octaver) to actually make good use of what I have, but it's fun.
Come to think of it, the mixer that I'm using to blend the sound back together has an fx section. I'll try assigning something to a channel.

Most recent try saw my signal path go:
Murf right channel > boss CE-2 > cheapo distortion > LPF > mixer
Murf left channel > mixer
The murf was set so nearly nothing below 160 hz was going to the right & nothing above it goes to left.

It's not just keys that step on your toes, guitarists can be equally as guilty (in my instance, one has an octaver on octave down! & the other uses a Godin with a synth set up so 1/2 the time I could play up the dusty end).

[DanOwens]

[quote name='xgsjx' post='1275606' date='Jun 20 2011, 10:11 AM']It's not just keys that step on your toes, guitarists can be equally as guilty (in my instance, one has an octaver on octave down! & the other uses a Godin with a synth set up so 1/2 the time I could play up the dusty end).[/quote]

I've worked a lot with guitarists but improvising electronic music is as much a mentality as it is technical skill or theoretical knowledge. Guitarists think in terms of chord structures, but you can't really improvise with chord structures without some degree of planning. This is where most guitarists I've worked with fall down.

To be fair, this is where most keyboard players and drummers fall down too.

Dan

[fatgoogle]

If you ever do a blog on playing with a synth player that would be great. Me and my synth player often have a lot of trouble with knowing what each other should do, as he can go as low as me and create a huge amount of sounds etc etc.