How to: Acoustic Recording

Once again, just a brief thank you and shout out to my continued international readership in Germany, Canada, France, the UK, and Russia! I hope these posts continue to amuse you :)

My First Accordion

Since the start of my aforementioned experiences in a recording studio I've been on a quest to find the perfect acoustic recording sound. This post will hopefully explain through example how to affordability put together a solid recording home studio system and WHY you need each part, which was something I had a hard time understanding. Let's start from super basic and work our way to the more technologically complex.

Daw is also a village in Mauritania according to Wikipedia

DAW. Computer Editing Voodoo
First and foremost you'll need to pick a D.A.W. (Digital Audio Workstation) to install your computer. That's the computer program you'll use to record/edit/save the tracks you record. I personally use Mixcraft because it's simple, professionals generally use Pro Tools or on occasion Cubase which offer a lot of control, and a lot of people use Audacity because it's free and open source. In short: the red circular button is the record button and the other buttons you'd find on a remote do the same things they'd do on a remote control. The weird little timeline that moves from left to right visually shows you the sound you're recording, and your goal is to make sure that you see signals appear when you record that are fairly visible but that don't hit the top of the line. When people say that a sound "spiked/peaked" in spots or that it's "too hot" it means that what you're playing is too loud for the D.A.W. to process so everything will sound muffled. So obviously step one is to make sure that your sound levels are set to avoid this. 

Easy options to avoid spiking:

1. You can play (or sing) softer 

2. Play farther away from the microphone 

3. Lower the volume of the track on your D.A.W., 

4. Lower your volume (on the channel you're using) on your Interface (we'll get to that later)

5. EQ the track on your DAW or apply filters like a "dehisser" or limiter. 

Before you start recording you should play (or sing) the loudest part of your song and watch to make sure that you don't spike. In Cubase/Mixcraft there's a little bar on the bottom right that will turn RED every time a track spikes. Adjust your settings accordingly but don't arbitrarily reduce the volume to barely audible because you'll enter into a whole new world of problems and pick up many other things (professionally referred to as "noise") in addition to what you're trying to record.

Noise

Interfaces: How it plugs into your computer
Now that you understand how to hit the record button and not record a track that's too loud we move on to the next important step of the process, the Interface. If you're plugging a microphone into your computer's "Microphone" jack it might sound good at a soft volume but you'll notice a few key problems later down the line, mainly that you'll likely notice a hum, repeated click, or whirring on your track that are caused by your computer. Don't notice it on skype? You probably wouldn't. Now try recording a soft impactful piece of music and raising the volume 150%. Now that previously inaudible whir is all you can focus on. So in order to get a microphone to plug into your computer using a port that's not the microphone port you'll want to work through what's called an Interface. It's basically a box you plug a microphone or guitar/other into that plugs into your computer via firewire/USB/other. Firewire is optimal because it reduces latency... Which is a sort of delay that won't affect the quality of the recording but it will probably directly affect your performance. Interfaces can be expensive and because I record regularly I got a quality mid-level one through M-Audio. As long as it has the inputs you need to connect to a computer, to a headset, and to your microphone(s) you can certainly go with something a little cheaper if you don't need many inputs. For instance, flute would probably only use 1 input but accordion might use two because it produces sound from two places that are not close together. The nobs control the volume (see above) and turning them towards the "-" will reduce the volume, and turning it towards the "+" will increase it. Note that your headset has its own volume, so you might be recording something a lot louder/softer than you're hearing it. I've also blown headsets when someone thought it would be funny to set my headset volume to MAX, or when I didn't realize I was recording at a high volume and foolishly raised the headset volume myself when switching instruments. Assuming that you know how a microphone cable plugs in, how a headset plugs in, and how to connect a firewire or USB from the interface to your computer you've mastered this section of the exercise. Another advantage to using an interface is the reduction of computer related "noise." Now you'll only hear your computer humming or clicking if your microphone is too close to it!

This looks legit, right?

Buzzing and Electric Noise
If you still hear a humming sound, a consistent beep, or a droning click (1:09-1:12 is a very good example) either one of two things has happened. Either your Interface is causing the noise, which generally happens if there's been a bad power surge (as I discovered the hard way), if your Interface is extremely cheap and poorly made, or if the electrical power in your home is not conditioned. Didn't realize that the electrical power in your house could affect your recording? Well there's a fairly easy ~$80 fix... Power Conditioning. In short, you get a cheap power conditioner and it will regulate the levels and take care of the electrical related pop.

Most microphones don't work like this

Microphones
Depending on what you're recording, you'll need a specific type of Microphone that fits your price range and instrument. I suggest using a condenser microphone (as opposed to a dynamic microphone), unless you're recording more than one instrument at the same time, while in the same room. The condenser will pick up more sound at a higher quality (and any background noise from around your [home] studio space like the AC, a fan, a person 5 feet away tapping their foot, coughing, etc). What I mean by "more sound": If you think of microphones as having a bubble or sweet spot that they are most effective recording at, a condenser microphone will have a larger bubble whereas a dynamic microphone will have a smaller bubble because it's designed to not pick up other instruments that would be performing at the same time.

I think this pretty much covers the basics. If you record with the above specifications you will be able to either mix your own tracks to a professional level of quality or find someone who can. Either way the unedited tracks you record will be recorded at a good quality. Oh, and be sure to export tracks as a ".wav" file (or other loss-less file type) or else the quality of what you export from your DAW will be reduced. Don't worry too much if this doesn't make a whole lot of sense... that's more a function of editing than recording.

If you have any additional questions about recording in general feel free to ask them here.

Tabletop: My Introduction to Infinity

Infinity Miniatures Painted by Chris Thompson

We interrupt the regularly scheduled blog entry to talk about a miniatures game I tried out this week: Infinity.

Let's start with the basics... From all the discussions I had beforehand (admittedly I was only half-listening because I was busy jumping Bears in Tokyo Jungle) I knew that it was a skirmish (under 20 miniatures for a full game) sci-fi themed miniatures game that used a lot of terrain, where the miniatures have excessive fan service at times, and that used some kind of D20 system. So, with this limited knowledge I was thrust into the role of the leader of a 6 man squad of robot-people called Aleph, to fight against the Space Templars (played by Stomphoof, also new to the game) in a practice game being moderated by a few guys who knew the rules. Our moderators set up the terrain, made practice lists for us, and slowly walked us through the rules as we encountered them...

The first thing I did was look at my forces chart:

I had over 3 special rules per character (Frenzy, 360 degree visors, Cube 2.0, etc), over 3 weapons per character, and more actions at my disposal than I understood. This is the miniatures game system I've been waiting for it seems. For simplicity I nicknamed each character by their distinctive weapon or ability:

Leader guy with a Mark 3 rifle (shoots 3 round burst).

Hacker chick.

Sniper chick.

Rocket dude (who can shoot 2 rockets per turn)

Flashlight chick (who has a gun that blinds people in addition to a submachine gun and a pistol).

Small arms dude.

All of my characters had fairly similar statistics in the double digits and it quickly became apparent that you want to roll under your statistic on a D20 in order to succeed at what you're doing. There are also D&D style modifiers making the game feel more like an engagement of well established D&D characters than a fight between useless minions.

Stomphoof  (on the left) and The Game Board

Before the game started it was explained that our objective was to hold a strategic objective (an outhouse) in the middle of the table and that we had 3 turns to do that in. Shomphoof and I shrugged and got started by rolling to see who got the first turn and who deployed first. I won the roll and got the first turn. Stomphoof got to pick the table side and forced me to deploy first (an advantage because he can see where my forces are before deploying his guys). With a 12'' deployment zone on my boarder of the square table, I set up my guys in cover, and my sniper on top of a tall gun emplacement/missile silo that had a clear view to the objective. I was told that this game uses a model's line of sight (meaning that if the model can physically see another model, the two can both shoot at each other) and that immediately made me happy to hear. Stomphoof had a "linked" unit, which moved as one and shot as one but all of my models were entirely independent. I watched as he deployed his guys behind cover (you have to be "touching" cover to get the benefit of cover) in his deployment zone.

Turn 1. I got a number of Orders equal to the number of models I had alive +1... So 7 orders. Each order can be used to either "Move/Move", "Move/shoot", "Shoot", or on some other actions (like climbing buildings) that we didn't get into too much. The first thing I did was move my Leader guy into line of sight with the enemy on the complete other side of the map. He got an immediate "reaction" to this and decided to shoot at me... Reactions are pretty cool and make it so if you run past an enemy's line of sight, they can either "dodge, shoot, or ignore" you, before you declare your second action. If you move out of cover at any point during the first move you don't get the benefit of cover as they shoot at you. Solid enough rules that I agree with. Now I had to start thinking tactically. So, after moving from cover to cover I shot at the guy who decided to take a "reaction shot" at me. His shots missed, and 1 of mine hit (pictured below). You roll based on your statistics, reduced by range, and special abilities (my guy has an optical disruptor, giving people a -6 to shoot at him and cover, which is an additional -3 to hit). I rolled a 4, which was well under what I needed, so I hit him while he missed me. Then he got an armor save (you roll OVER your armor value, which is modified by the gun's Armor Piercing value) and by fluke his armor deflected the shot. After being hit and not being wounded, he took a Willpower test (for being shot and surviving) and failed, forcing him to hide behind cover. I was feeling pretty good about this, so I moved rocket dude into the line of sight of another bad guy and shot at him with my rocket launcher (which shoots 2 rockets at a time!!). I rolled and got one hit, but Stomphoof's reaction was to shoot at my Rocket dude. Because his guy succeeded in hitting me, and rolled higher than my guy (who also hit his target) Stomphoof's rocket guy hit and cancelled out my shots. My Rocket dude failed his armor roll and was knocked out (0 wounds = unconscious, -1 = dead), but because we lacked medics this effectively meant he was dead. Upset at this I declared that my sniper would shoot at Stomp's rocket guy in revenge. His reaction was to shoot back at my sniper with his last rocket. The exact same situation played out and his rocket guy killed my sniper chick.

By this point I was seeking revenge because this guy effectively no-scope blind-fire murdered 1/3rd of my kill team BEFORE IT WAS EVEN HIS TURN. It reminded me of X-com: Enemy Unknown in a good way. The rest of my turn was spent moving my Leader guy forward and (successfully) shooting Stomp's rocked guy to death while evading incoming fire. In this game you can spend multiple Orders on the same unit each turn (no cap), which is justified thanks to the whole reaction phase of the game. (Every time you shoot at someone, they can shoot back).

My First Roll of the Game

Despite a few people in the shop muttering about how difficult the rules to Infinity were, Stomphoof and I picked up in the gist of the game in under 20 minutes and found them infinitely (no pun intended) more simple than Warhammer, 40k, or any variations therein. True line of sight (with both models being able to shoot each other if one model can see the other), their approximate range modifiers, and the low model count make the game (once you understand the basics) go by fairly quickly without much room for rules disputes and it's already my favorite miniatures game this side of "Warhammer: Path to Glory." 

Stomphoof's turn was one of tactical movement. We learned how to interact with terrain (physical checks where you roll under your relevant statistic after modifiers are calculated based on the terrain) as he jumped through windows, into a half-pipe sewer system that led to the objective, and safely hid underneath a bridge without getting a single successful reaction shot from my side. His models were mostly close combat orientated so it made sense that his goal was to run towards the objective without being seen.

True Line of Sight

On my second turn, with significantly less actions this time around, I climbed a building (at the wrong part of the building admittedly, exposing myself to lots of unwanted but unsuccessful reactive gunfire in my direction) and shot at the guy under the bridge from a vantage point. In short, he returned fire, killed Flashlight chick, and was killed by Leader guy. I was told that his Leader had died (which normally causes all sorts of panic) but this his forces were religious fanatics and didn't care. My Leader guy took a bullet to the face and also didn't care because he's a robot and never falls unconscious, despite dropping to 0hp. I moved the rest of my forces into position to take the objective and ended my turn with everyone in cover. Stomphoof's second turn allowed his linked squad to see my Leader guy and shoot at him while they were jumping through a broken window. Despite my best efforts, Leader Dude was shot to death and I pondered why I hadn't used the visibility blocking smoke grenades earlier. It was at this moment that we learned about the rule that if a player drops to 2 models or less, they immediately run away/forfeit.

Game over and I still felt really good about things. It's a smooth game where your turn never really seems to end (because of the reaction phase) and I felt like I fought an evenly matched battle. I was already itching for a more tactically played rematch the moment we shook hands but time constraints prevented this from happening.

Now, a few days later, I'm in the process of figuring out which army I want to play... I'm including my thoughts here and should/when I get to building/assembling models I'll also share that in future posts.

The Factions:

Pan Oceania: They're the ultra-prosperous super-nation. Tech-heavy but still very human, the models seem like a crusader army mix of man and machine in an art style that doesn't appeal to me. They seem like a tough opponent though. I think this is what Stomphoof played last game.

Yu Jing: They are regularly described as a mix of ninjas, samurai, and transformers, which doesn't interest me much. The models look neat, very Cyborg Ninja, which isn't my thing despite being awesome.

Ariadna: They are modern tech highlanders, were-wolves, French, Russians, and Americans in a sci-fi world. While that makes them sort of redneck (using early 2000's technology in the year 2150) it's in the running for the faction of choice. I never really understood the kilt thing, and am not really all that into werewolves (being in a band that specializes in hunting them), but a Russian-American-French army seem kind of neat.

Haqqislam: Harmony seeking Islamists aren't normally my style but it looks like a very hit n' run army, which greatly interests me. This would be a sniper-town army.

Nomads: Bandits, traders, and ex-cons who've banded together. This initially was my choice until I saw the models and realized that they're basically an anime faction. While some of the models look absolutely awesome the fact that their forces include a cat girl automatically excluded them from being a viable faction in my eyes.

Combined Army: A super faction of alien races. Stomphoof called it the "Monkey Man and Bug Army" and I can't really disagree with his assessment. While Stomphoof said he'd pick this faction and I agree that the models look awesome, bugs and monkey men are not my thing.

Aleph: An AI faction filled with cyborgs, Tron-bikes, and references to Greek mythology. It reminds me a lot of System Shock for some reason and I'm interested in them for that alone. I'd probably make a robot army led by a SHODAN look alike.

Tohaa: Bio-tech aliens that strongly remind me of the Council Races from Mass Effect. This faction strongly interests me for aesthetic purposes, and the fact that bio-warfare means extra damage with each hit. The downside is that they only seem to have 9 different models available at present. I'm told that they're the newest faction in the game, which would help explain this, and i'm not above converting models if the rules for the army aren't horrible.
Mercenaries: Corporate warriors and a large slew of awesome models. Sadly they seem banned in most games that my friends take part in or I'd likely pick them.

I'm really leaning towards Tohaa, Aleph, Ariadna, or Haqqislam but am at a bit of a split decision.

While i'm in the process of picking which faction I'm going to play I welcome any comments suggestions and thoughts you might have on the topic.

Pre Blog: Music: I want to buy an accordion, now what?

[Copied from my old Blog]

What to look for in an accordion
A guide to finding the right instrument for you.

Someone recently asked me what to look for when purchasing an accordion and it suddenly dawned on me that i'm somewhat knowledgeable on the topic. Having learned a fair deal of the instrument's intimate secrets (I know all the buttons, speak "Converter Bass", and have successfully crowed surfed while playing an accordion) and played for the last 8+ years here are my thoughts on someone wanting to "pick up" the instrument. Keep in mind that this guide only covers "Accordions" no "Concertinas".

Have you ever seen Cowboy Bebop, Vampire Hunter D, Warhammer 40k, Fallout, or Lord of the Rings? These worlds have a kind of scavenger mentality of "oh, they don't make 'em like they used to", whereby the amazing technology of old has been lost and needs to be sought after, recovered, repaired, and cherished. Well, looking for a good accordion is kind of like that. You can certainly buy a new accordion if you know where to go (I've been through a lot of places in the South-East U.S. searching for a quality accordions), but you'll generally find the models at your local music store sorely lacking and overpriced. It's also important to note that like in Harry Potter, every person has an accordion that's just right for them... It won't be as easily apparent as casting a spell but what I mean is that every person has to make some very personal decisions that decide what they are looking for when choosing an accordion that's right for them.

My accordion of choice, the one I play at shows and use for everything (except studio recordings) is a forty year old Titano "Combo Cordion". It's small, light-weight, has a decent sound, an amazing microphone system, and a unique "quint-reed" switch which automatically plays fifth notes every time I hit a key (only when activated).
Titano Combo Cordions are generally eccentric in color (bright orange, yellow, pink, or green) but I've given mine a fairly nice paint job that matches my band's color scheme. It's everything I want in an accordion with the exception of reed diversity, which is why I don't record with it.

The First decision is Size: A larger accordion generally has more keys (a greater range of notes), different reeds (Aka voices or sounds you can produce) and other features (some have midi, converter bass, a quick-reed switch, etc, [covered later]) but weigh more. I have scoliosis and play hour long shows where I jump around a lot, so I play with a small accordion (20-30lbs as opposed to 35-60lbs).

The Second decision Key Size: Look at a keyboard, piano, or accordion with keys (some have buttons on the "right" side which act like keys). You will notice how thick or "wide" the keys are when you put your finger on top of them. A traditional piano or keyboard uses regular sized keys. A kid's piano or keyboard uses smaller keys because kids have smaller hands. A women's piano or keyboard uses slightly smaller keys than "full sized" ones. All of this translates into an accordion. Smaller keys means you can fit more notes or keys on an accordion. Most small accordions generally have two and a half octaves, larger ones have three+ octaves but it's all relative. I've even seen a sad full-sized accordion with only one octave of notes. More is generally better, but only if you'll use them. Most people don't use the highest or lowest notes on a piano, so just be aware of the range you'd like to be able to cover.
A smaller key size also means that you can play a larger range of notes because the keys are less wide, allowing your hand to stretch over more of them. It's pretty nifty when your hand can cover the range of almost 2 octaves, but it's suddenly less awesome when your fingers are fatter than the keys and you can't play the notes you want to (e.g. children's sized keys).
If you can't tell the difference in what you're looking at ask your sales associate. If they don't know, like the harry potter wand principle this is all about "what feels right" to you.
Sub-Topic to be aware of: Key Click:
I bought an accordion from Sam Ash, a Carlo Robelli [http://www.samash.com/p/Carlo%20Robelli_CR3473%2034%20Key%2072%20Bass%20... ] that miraculously produced some of the best (keyboard-side) reed sounds I've ever heard. I picked it up as a joke at first but now record pretty much everything I do with it (for the keyboard side). This is in spite of the fact that I dislike that it's a 72-bass and that it's horribly notched in the wrong places on the bass side (see below), I traded in my live-performance accordion at the time (a full sized 120-bass Scandelli with Midi modifications) in favor of it because the sound is incredible.
Thinking the Carlo Robelli would translate well to our live show "rock environment" because of the size and sound I tried to attach an external microphone but it gave me too much feedback. So I paid for the surgery to get it an internal mic. The accordion itself held up fairly well (though I broke 2 reeds over 4 months which is kind of bad considering I haven't broken any before or since), but the mic kept picking up a slight poping sound every time I played a note. It turns out that the keyboard produces a "squeaking" sound every time the keys are depressed (let go of), which the mic picks up and amplifies. This isn't found as prominently on high-quality accordions but should be something you're aware of. Incidentally the internal mic I picked wasn't the best so the translation from "uber-sexy amazing sound" to "this is what the audience hears" didn't work out too well. So I switched to the Titano I found while browsing 'Accordions and Keyboards' in Clearwater, FL.
It's also worth mentioning that the clicking sound is in many of my recordings (I still use that accordion for recording) and will be for a long time until I can find an accordion capable of producing a better sound that doesn't click as much. I occasionally use it as a "proof" for people who think we're using midi accordion.

The Third decision is the number of Buttons:
My accordions need to have 120 buttons because I intend to play songs with complex bass jumps (aka anything except traditional polka).
In simple terms: If you intend to play songs from your favorite rock band, or video game music, or anything that reads "B Major(or minor), F# Major(or minor)" you should not settle for a 72 bass (or less) unless you want to limit your abilities. Accordions come in all numbers of buttons, regardless of size. I've seen 4, 6, 12, 42, 72, 90, 120, and 160. I highly recommend that you go with 120 unless you're a polka master (who doesn't intent to play anything else). Again, I can't stress enough that if you're going to pay $300+ for a "starter accordion" you might as well get one that you can play well. The button side is all about playing different "chords" (each assigned to a button). The convenience is that you play an entire chord at the push of a button. It seems counter-productive to place the buttons you want too push far apart or you will decrease your chances of being able to play a song. For instance, the Legend of Zelda theme, when played on the 72-bass Carlo Robelli requires you to push the button at the very top of the accordion, then immediately jump to the very bottom.. and back... twice in a row. On a 120-bass you simply move over to the next button above where the top button on a 72 would be.
What's a 160? It's simply a 120 with an extra row or two of "bass notes". If you don't mind the extra weight and like playing a counter-melody on that side it can be worth your while.
Sub-Decision: The Grooves:
Your 72+ bass accordion should have "grooves" or "notches" carved, indented, or protruding from the "Ab" "C" and "E" buttons that make playing a lot easier. If it doesn't, you can always add this with a dremmel, knife, or drill, but it's generally easier if they come with the grooves. If the grooves are on the wrong buttons just be prepared to be somewhat confused if you pick up another accordion. This is another flaw of the Carlo Robelli who has grooves in the "Eb" "C" and "E" buttons. These groove are designed to help your fingers jump from button to button and keep you orientated. You can certainly play without them but they're just a nice thing to have in the same way frets are nice to have on a guitar.
Sub-Decision: Converter Bass:
"Converter Bass" this means that the accordion bass side has a secondary mode of playing that I've personally never found useful where each button is now a specific note within a 3 octave range, as opposed to a chord. I own a very fancy "Converter Bass" Pan Italia and find it somewhat dull and inferior to the Chordal sound I associate with the instrument. Converter Bass seems to lack power in all models I've seen it in and I've never seen a "Converter Bass" in use by any live performing musician or recording beyond obscure accordion solo artists. It might have seemed like a really cool idea when they started making them but if someone is charging you extra for this feature you may want to mention that it's not that important to you and see if there's anything similar without it. I'd also like to add that every extra reed-feature you add to an accordion adds weight to it, which is a huge factor for me.
In short: If it's a good accordion that features a "converter bass" switch, you should get it because it's a good accordion and not for this feature.

Now that we know what your accordion should LOOK and FEEL like, it's time to decide what it needs to SOUND like.
The Fourth decision is Reed Variety:
This one is fairly easy and broken down into two sub-questions:
What do you want your accordion to sound like? How many different sounds do you want it to be capable of producing?
To pick a sound you like simply pick up the accordion and start playing each side respectively (The button side, the keyboard side) until you find something you like. Don't just hit a single key on the keyboard side, try playing a few chords, maybe tinkering around with the high and low notes too. If you're unable to play chords let someone else play on it and listen to them play.
Many accordions also have multiple reeds (voices/sounds they can produce) apparent through switches/buttons/knobs above the keyboard so it's important to test them all out... After all, some poor Italian guy put countless hours of hard labor for your instrument to produce each one. The least you could do is show the guy some respect by trying them all out because one of them might be truly spectacular.
On the button side you should also try playing different chord buttons and root-note (bass) buttons. Same principle as with the keyboard side. Some accordions also feature multiple reeds (voices/sounds) on the bass/button side. Keep in mind that each extra reed/sound adds noticeable weight to the instrument. Even so, all of the accordions I own have at least 4 or 5 different sounds it's capable of producing.
While you're testing the keyboard side, (if it has multiple reeds) make sure the accordion you're getting is capable of producing more than one sound you are fond of so you can switch from maybe something light/delicate to something French sounding (Generally labeled "French/Musette") to maybe something deep (generally the "Master" Reed). Those are the three sounds I generally shoot for because they are the 'quintessential sounds' people associate with the instrument, but again it's all about what you like.
An accordion with just one sound is fine so long as it's a sound you like. Extras are just a perk.
The average small sized accordion has one sound (no switch) for the bass/button side, and a full sized accordion will generally have between one to five.

Once you've found some sounds you like, do yourself a favor and MAKE SURE ALL OF THE KEYS & BUTTONS WORK. I can't stress this enough because you can easily drop an extra $200 or $500 trying to repair something once it's broken. Do yourself a favor and spend the extra few seconds on each reed and make sure it works. Also, the accordion shouldn't produce sound unless you're pushing a button or key... That's a sign that repairs are needed. While you're focusing on the keys you should also make note of any sticky buttons or keys and see if those can be fixed prior to your purchase.

Now that you have the basics, here are some perks you should be aware of:
Color and style: I can't help you here. Get something you like to look at if possible. Otherwise it should at least sound good. Some accordions (Like my Titano) have inverted key colors, which is cool but doesn't affect how it's played at all.
Keyboard Orientation: Some accordions have the keyboard facing at a right angle to the rest of the accordion. While this might seem cool at first first verify that it won't dig into your side before purchase.
Some accordions have a switch on the bottom, top, or right side of the keys that is a quick-switch to the master reed. It's actually a really useful feature, though it isn't found in most accordions.
Conversion Bass: (See above)
Quint-Reed: A somewhat rare feature that automatically plays fifth notes every time you hit a key (only when activated). It can make for a more full sound at times. It's a cool perk if you have a use for it, and its something most people can make good use of.
Dual keys: I'm told that 8 accordions in the world have keys on both sides of the accordion (as opposed to buttons). I've not verified this but had the fortune of being close to one of them. They are very rare and play almost identically to a piano.
Dual Buttons: The buttons on the keyboard side are basically a substitution for the keys. It sounds the same, it's just a different way of playing.

Bonus Stuff:
Internal Microphone System:
My accordion has a really good internal microphone system that it came with (from the 70's(!)). If you want to amplified sound I highly recommend going with an internal system. It's pretty awesome when you can amplify yourself with no feedback on an acoustic instrument because the mic is inside, protected by the instrument's hard casing. I've tinkered with attachable external microphones and they don't work well if you move around a lot on stage, play in a windy environment, or play in a rock environment. They work really well for acoustic sets though.
Also, don't just take someone's word that an accordion is mic'd well, ask them if you can try it out because you might find that it needs some repair, or has a pop, or is an extremely low quality mic that needs to be replaced. It's around $700 for an internal mic so if it's broken you should ask for it to be repaired/replaced before you buy it. For optimal results in your test, turn down the "high" frequency and treat it like a keyboard with whatever amp you're using (Aka, don't use a "guitar amp" if possible).

Midi:
Midi is also a somewhat common feature in accordions. It's pricey and some of the older stuff (year 1999 and older) has really low quality audio samples stuck and built into it. I don't currently use midi because of the weight factor (I put my accordion on top of my head so every pound is important to me) and because I strive for a real accordion sound being made by a real accordion. However, I have seen (and own) a number of accordions that produce really nice sounding midi. Being able to practice quietly with a headset is nice. It's also cool to be able to replace a bass guitar, rhythm section, and lead instrument (and a drummer if it's a really nice midi set) on your own. Many years ago I was able to perform as Random Encounter with just myself and one other person, sounding like a full band. Some accordion midi sounds also sound better than real accordions and can help you avoid using a microphone, and can be significantly lighter in weight than a regular accordion of the same size. As always, test this feature before purchase for sound quality and bad connections or wiring. Midi is powerful and it's an option you should be aware of.

I hope this has been a somewhat useful read and help you on your path to the sacred and mysterious art of accordion playing.