Tag Archives: filters

Brad Ormand - Renegade Rambler Audio UI idea

2016.03.01 – Audio Granulator Progress

While in the process of writing an audio program for the ARM chip and another display, I began to also write code for Mac OS 10 and iOS.  I hit some good vibes and continued going forward with the Mac app and left the ARM system on the bench, as is, to come back to later after I finish this Mac app.  I switched gears, as I normally do, but I now have the pieces together to make this app, and it’s multiplying my motivation…

I have been studying DSP and audio algorithms in C++ quite a bit lately (and I had already made great progress with the DFT and FFT in 2015), and am having a great deal of fun analyzing and manipulating sound.  My degree and background are from this area, but I have never had to actually code a chorus or reverb or EQ (although I’ve built hardware analog EQ’s and compressors).  So… I decided to go through making this higher-level abstraction app to beef up more of my real-time digital audio knowledge.  I’m using Core Audio and Audio Units.  Then, after one or two of these apps, I can come back to the bare ARM system, with which I’ll have to write these “units” from scratch (and I can’t wait – looking forward to it.  Just need a quick win first, ‘cuz I’m gon spend some time on it – like a year).  It’ll also help me decide how I’m going to organize the higher-level abstractions from my low-level C++ code once I get back to coding the embedded ARM system.

ARM Breadboard Circuit 1 Brad Ormand

I’ll have the fast FFT implementations and FIR and IIR filters in the CMSIS DSP lib, etc, and I’ll at least have a fast sine and cosine routine, but it’s a lowest-level implementation that I’ll have to “hand” assemble to be a 4-pole LPF or a phaser or even a simple notch, etc.  I’ll have to make my post-DAC “Nyquist” filter at 22kHz and all of that stuff on the ARM system in hardware, etc.  It’ll be at least 44.1kHz at 16-bit – I want (people) to be able to actually use the audio generated by it – some really killer and sonicall-pleasing sounds.  So, that’s coming up…

Brad Ormand's Second Fourier Transform - Noise

It’s kind of a tall order for me.  I have some work to do before I can write a digital audio system from scratch at the chip/embedded level – from Math to code to electrical components. I can’t wait to do it and spend time on it, but I must prepare.  So, I did a few mathematics problems this weekend dealing with impulse response and the summation of the FIR filter to get to know what I’m dealing with.  So, I’m going to do it all step-by-step in my free time until I’m able to grasp it and code good implementations.

M A C   A U D I O   A P P

I have been successful at building a Core-Audio-based sampler for iOS in C++ and Swift.  I have a functional demo that starts and ends the time window at particular points along the audio clip using touch – all real-time.  My next step is to draw the waveform out into a SpriteKit view and to get the app to respond to the touch drags to resize the play window to the visual waveform on the UI.  Just that part itself has been a bit tedious, not-to-mention any zooming of the waveform, which hasn’t even been considered, yet.  Then, of course, I’ll need to render out the playhead rolling along as the samples get played.  There’s a lot of interpolation that has to be done since there aren’t enough pixels to show every sample, and I’m trying to get that stuff out to it’s own thread and to see if I can somehow pre-calculate it all when it first comes in.  I made a pencil sketch of the UI to come – it’s the initial view, but I’ll have a keyboard or sample pad view of sorts.

Brad Ormand - Renegade Rambler Audio UI idea

As for the audio source, right now I have it playing from a file.  But, I don’t think I’ll let the user bring in files with  it.  It’s just too weird on the legal side since I’ll let the user save it back to disk, and I have to detect and convert what type of files they attempt to load in and stuff (mp3, ogg, AAC, which wav, etc), and well…  I really just want the user to be able to press record and mess with the stuff that gets recorded, and probably with a 15-second limit – focus – kind of like Twitter’s 140 char limit.  That audio will then be recorded into and played from a file of course, but I can count on it being a 32-bit float PCM format, and just run with it.

In the end, I want the thing to act as a granulator, where you bring in audio and are able to loop sections of audio at really tight intervals, or even with randomized time and pitch parameters, where it acts as a sound design tool.  I do this in Pro Tools all the time by hand and cut samples like 1000 at a time and shift them incrementally and copy and paste them offset next to each other for effect, but it’s definitely time-consuming.  I’ll probably still do that because I have ultimate control, but I’d like to be able to go into the app environment and get sounds from machines or birds or rubber bands or my voice or even the wind and allow the user to really fuck with them to make them something else entirely.  Of course, they’ll be able to save the original tracks and save the performance.  And, I’ll offer a few time-based effects and definitely some distortion and crush on there, too.

So…  that’s what I’ve been getting into.  It’s after-work stuff, so it’s kind of slow-going after a day of already programming for hours at the day job, but I’m making definite progress and can’t wait to circle back to the embedded system, as well.  I have many, many things to look forward to on this front.



Brad Ormand Music 2015 07 17

07.17.2015 – I Love You

I put up a new version of “I Love You” this evening after working on it for a little bit, cleaning up the vox and adding a nice little melody.   I wanted to make the sub-bass kick hard with the bass drum, so I kind of “blended” the two with some cutting EQ for some tight interlacing.  There’s a lot of sub there, tied to the kick, and I want the typical car system driver to feel the bump in their chest and throat – and to feel the sub in their armrest, so I added a few freqs at different q’s to the kick to really cut through – like what an 6″ or 8″ sub is good for.  And, as for the sub, I decreased the 60 to 90 and accentuated the 30 and a half and 40 – like what a 12″ or 15″ would be good at.  Big bass!  But, with a tight kick – as I did in “What You Lookin’ For?”.  It really helps the chorus feel fat, too.

I also added a little melody line in a high synth hollow triangle sound that mirrors and accentuates the vocals pretty good.  It’s a bit funky, too – couldn’t help it.  Love that kind of stuff.  I have recorded these vocals like…  about 8 times to get the right feel.  Bout time it started to come together!

Also, I cut some parts out completely – a few parts that I sang that sounded really exotic and has good potential for dance.  While I’m sad about not using them in this song, I just can’t justify it for this song’s continuity.  It’s the nature of the biz.  I’ll revisit them later for a more appropriate song to tie them with.

Brad Ormand Music 2015 07 17

And, lastly, the lead vocals needed a lot of tenderizing.  Like, I cut a lot of 2k-ish and took some 500 hertz honk out of them.  I increased around 8k and made them sizzle a bit, along with a little more doubling – on top of all the other past EQ.  I increased the level of the second harmony for a bit of solidarity and the whole stem is sounding pretty good.  I’m surprised, actually.  I never thought I could *really* get this cut to work.  But, it’s turning out ok.

The cymbals on the chorus I left pretty much as they were.  I played two takes of sticks on a bell of a 16″ Zildjian A from, like 1976 (or something) – it’s a really old school cymbal with the marks rubbed off that I hand-picked when it came in used to a drum shop I used to work at.  I used to go over there and test crashes for a prime non-standard-sounding candidate, and this is my favorite one.  I hardly gigged with it since I wanted to preserve it for the studio.  It’s bad, man.

Ok, that’s it.  I’m really excited about this song.  I think it has some good potential for the market, and well…  I really like listening to it – That’s the main part of all my songs – if I keep listening 🙂  Take care.

Brad Ormand - Waveform of Good Kick

10.10.2014 – Analog Filters, Skrillex & Philosophy

Ahhh, yeah.. Detour yesterday. I forgot that I had ordered some (like 3 of them) Analog filter design books last week – used, for like 1/10th of the price, each (Goodwill listed one that I had been looking for for a long-ass time that went for over $130, but I got it for 8 bucks.  It’s totally readable – I mean it’s just like the books I got used from the University bookstore – totally all good for learning the information contained inside, even if there *is* writing in it). Totally exciting.

Well, I got one in yesterday, and I dove in. Totally informative. I had held off on getting them before because they were all well over $100 each. Anyway, I had been wanting to clarify and solidify my knowledge of signal filter circuits – for audio frequencies, especially. I’m not going to redesign my Audio Tool, but for my next projects (specifically the synth), I want to be very precise with my values.
There are 2 things that I want express about this whole experience:

#1)  The purpose of diving in to learning this topic is precisely so that I can deeply understand the theory and coordination between the components in each configuration so that I can commit to memory the operation of each configuration.. So that when the time comes to design a certain idea that I have for a device, I can just pull out the myriad of design angles from my mind at that point in time and get right to designing it without going to books or the internet first. It’s like having tools in my toolbox that have been tempered with experience and focus, ready to be used in the real world, instantly.  That’s what I’m going for, in the end.  That’s probably how Edison and Einstein and Michelangelo and Leonardo did it, I think…  Like, being able to produce on the fly with existing knowledge – not always having to detour out, saying, “Now, what was the way that went again?”,  “How do I do that again?”, “Better ask Google”.
#2) The reason for getting 3 books on the same subject is for reinforcement. I take this approach for pretty much every topic I learn – I get multiple sources. One author teaches from his/her experience, another from thiers. Also, it’s parity towards authors who may not be so experienced, or are motivated to write the book to impress their peers or for publishers to make money.  I’m not cynical about this, just aware that this exists and that it’s human nature and it’s “ok” to do so, but it is noise over my endgame. Never can know.

I’m also looking for real love of the subject by the author. There are just a lot of books to choose from, and establishing habits at the beginning of learning something is very influential later on and hard to break, thus..  the 3+ sources.  The important thing to me is the actual understanding (leading to real-world capability) of the subject to use in daily life.  So, by having a few sources of learning for a subject, they act as patches over each other – where one book was weak, another may “fill in the gaps”. So, that’s a sentiment that I have been wanting to write down for a while. 🙂

Anyway, back to the topic at hand…

So, like 6 hours were dumped into 100 pages of analog circuit design yesterday – following schematics, more theory, etc…  I sat outside in the breeze. However, I did manage to mix out some songs: “Kitchen” and “Looking for” for kick and sub frequencies. Better, both of them.. But, still needs more work. The kick on “Looking For” is nearly perfect for what I can do, and I’m stopping right there, but needs some sub help on the chorus. Ahh – so tricky…

“Kitchen” is gonna have to have it’s kick replaced, I think (again) – can’t get this kick I recorded to work (it’s an 18×22 kick I have in my studio), tuned low with its fundamental at about 47hz. It just doesn’t have the tight characteristics I’m looking for for this particular mix. Plus the bass guitar is high and tight, too. Ahhh, on second thought.. I’m just going to re-mix the bass and kick altogether. There should be enough 80 to 200hz frequency info in the beater-side track.. I’ll version it out. I’m somehow gonna get it right and tight, but keep that 50hz resonance, slightly. I’ll try that.


And, the version of “Dive” that I did Sunday rocks so hard. I really love it’s sub & kick frequency combo. Also, I think “Fine” is working out nicely as well. I mean, I do hear some inconsistencies between mine and commercial tracks. I know I am not “matching up” to the best of the best, yet, but I really do think this is my best mixing ever – It’s a far cry from what I was producing 5 years ago, and in another 5 years, I think I ‘ll have come in to my own personal resonance 🙂

Speaking of Far Cry (I mentioned it…)..  haha I am looking forward to Far Cry 4, for real.  Love the series, played them all to the bone.  Big environment, great textures, immersive world, story – all of it…  Highly influential to me…  Plus, they had Skrillex’s track (Make It Bun Dem) in a prominent scene in the main story in FC3.  Oh god..  Just love to hate that track because it’s so good.  Lightens my life.  Love this guy. All of his stuff is gold as far as I’m concerned.  Dat boy good…  Plus, I’m loving, right now, the Reggae philosophy of peace, love and happiness and harmony, mon.  For real.  Irie! So, I took a liking to it.  The kick audibly clips, but sounds so good, actually. (I’m not a traditionalist 18db-of-headroom kinda guy 🙂 ) I had to study it, since my focus is on kick & bass mixing right now.  It’s got this certain knock/punch, but also has the sub to match – all together balanced.  One of the best I have heard for impact – louder than most.  Here’s a waveform capture.