TungstenSF: Mercy II and Houdini

Enjoy!

That means that although it’s perfectly possible to spend five thousand dollars on a beautiful, sturdy, prestigious, great-sounding bass rig, I’m not really interested. There are quite a few premium brands that cost a ton, sound great, and have great endorsements (SWR, Trace Eliot, Eden, etc.), and other brands that made a name for themselves by making very good products but less prestigious and very reasonably priced (Carvin, etc.). In both cases, the default strategy is to buy a massive all-in-one amplfier with oodles of power and two massive cabinets (4×10 and 1×15, typically) from a well known brand and just turn the EQ knobs until it sounds good. This is really expensive, and leads to situations where you have to carry three bulky 60+ pound items everywhere you want to play. Nowadays the trend seems to be to replace that with a single large 90+lb combo amp from the same set of vendors. (Here’s an example from Aguilar, yours for only $1,900.00!)

Ironically, in larger, fancier venues, the house PA tends to be loud and includes stage monitors for the band, so a bassist doesn’t necessarily need to bring anything bigger than a medium sized combo amp. Sadly this is not something that the average working bassist encounters, so it’s still necessary for the rest of us to own some kind of loud rig.

One alternative that become popular in the 90s, as bass players started to be loud enough onstage to be able to experiment with tone, was the use of rackmounted components instead of an all-in-one approach. The bassist could pick a preamp for tone, a power amplifier for volume, and effects processors for fun sound experiments. Some famous artists have gone through phases in their careers where they went crazy with complicated racks and then simplified with a single vendor approach and an all-in-one amp head. Being a rebel and a nerd, and being generally dissatisfied with the flexibility and cost effectiveness of all-in-one amps, I decided to go with rackmounted components.

My theory is basically a best-of-breed, or perhaps best-deal-of-breed approach: pick individual components based on features, tone, and cost, and save big money by unbundling lame components from desirable components that would otherwise be sold in the same package.

So, my current rack includes:

• a power conditioner (basically a rack mounted power strip)
• an ADA MB-1 bass preamp, which is a sort of retro product from the 80’s that is tough, feature-rich, completely MIDI-controlled despite having an analog signal path, and cheap
• a TC Electronic G Major, which is a pretty fancy mid-price-range digital effects processor intended for guitar
• a QSC USA 400 power amplifier

The MB-1 (including a bunch of MIDI controller pedals) was $167.50; the power conditioner was $79.95; the G-Major was $285, and the power amp was $102. The rack itself was $139.95. So, for under $800 I have a super sophisticated setup with amazing tone. I absolutely love this setup, even though it took a lot of fiddling and reading to get it to do what I wanted; it is amazingly flexible.

But, it’s just not loud enough. It’s loud as hell in my apartment, but in a studio with sound dampening materials on the walls and a heavy metal drummer, I have to tweak and tweak the tone to be heard without driving the power amp to the point where its clipping limiter is kicking in. So, instead of selling $800 of gear and looking for a higher wattage version of the same thing (and probably paying for bundled features I don’t want), I went shopping for a similar power amp with more power.

It turns out that the power amp market has been fairly commodified, which is good for me. I was able to find several good brands (QSC, whose product I was very happy with; Crown; and Peavey) with suitable products. There are quite a few cheap and crummy brands too, but fortunately, community review sites identify them clearly. So, shopping boils down to specs, combined with a constrained set of known-reputable manufacturers. This is not unlike buying PC parts, really.

My speaker cabinets are Bergantino HT112s, which as far as I can tell are the best speakers money can buy at that size. Each has a single 12″ speaker and a tweeter, and are rated to handle 300W through their 8ohm load. I selected compact, loud, really great sounding (but expensive boutique-y) speakers for my own convenience, but for the sake of this technical discussion I could just as easily be talking about any decent cabinets: 2 cabs, 300W 8ohms.

They are identical because part of what I wanted to do with my fancy setup was to run stereo effects: chorus, reverb, etc. which sound dramatically better in stereo. As I mentioned in Part 1, biamping uses dissimilar speakers to get better tone for the same amount of money, but usually at the cost of punch; I didn’t want to sacrifice punch. So, I got speakers that can handle a lot of power, and I demo-ed them for about 45 minutes alongside other similar speakers at Bass and Beyond in Sacramento. (Thanks to Juan at B&B for steering me right; I was gonna buy something else but he gave me advice and let me sit there and rock out on all of the alternatives until I was convinced.) The size isn’t an issue because you can simply shove more power through them to get more bass, as compared to my previous bass rig that could handle less than half the power (but which was biamped).

So I set out to find a power amp that would deliver 300W per channel, stereo, into 8 ohms. There are unfortunately several ways to measure power output of an amp — a 1KHz sine wave vs. 20Hz-2KHz pink noise — and really what you’re measuring is how much power it delivers with a certain amount of maximum distortion (in a power amp, distortion is bad bad bad because it can damage speakers, and generally sounds terrible). So you have to kind of match up the fudging and exaggeration that vendors use to pump up their numbers. QSC’s web site has a power amp selector that suggests that your power amp should be able to drive 1.5x to 2x as many watts into the speaker as the speaker is rated for, and once I started looking for that I found several people who agreed with that rule of thumb.

So, now I was looking for up to 600W per side into 8 ohms, which is… how loud is that, actually? Well, it’s pretty expensive, I know that: $1000 or more retail for just a power amp, compared to $100 for what I had, which was not quite loud enough. So maybe there was a lower power level than 600W that was plenty loud and affordable. The question was, how loud is loud enough, in watts (per channel into 8ohm speakers)?

Well, yesterday in the studio, I figured out that my rig combined with the old, kinda crummy practice rig in the studio, were more than loud enough. Both claim “400 watts” but mean something slightly different, and not at all the same rating I was looking for. The QSC USA 400 delivers 200W per channel into 4 ohms, for 400W total, but that’s with the 1Khz sine wave measurement, and my speakers are an 8ohm load. So for my speakers and a 20Hz-20KHz signal, it’s delivering… drum roll… 110 watts per channel.

So, assuming for my purposes “watt” means “watts per channel stereo, with a 20Hz-20KHz signal into 8ohm load”, I bought 110W of amp for $102.50. That’s pretty close to $1.1/W.

$660 (600W power limit for my speakers, at $1.1/W) was out of my desired budget. But did I need 600W? Nope.

The other amp at the studio that made the combined setup loud enough was also “400 watts”, and I had a hard time finding specs because it’s so old, but it’s a Peavey Mark IV 400, which according to many sources I found delivers 400W into one channel at 2 ohms. The QSC 400 can deliver 250W per channel of a 1KHz sine wave into 2 ohms, therefore I figure that the Mark IV is probably less powerful than the QSC 400 given any particular load. That means I probably need a little less than 220W per channel for my setup, or $232 worth of power amp, to achieve “loud enough” status.

Now, how loud is that? Well, I don’t have the equipment to measure nor the engineering education to compute from the specs the decibel level of the sound I’m calling “loud enough.” But I can say that standing in front of the studio’s amp or my current rig while I’m playing will cause pain (during treble-y spikes) and probably hearing damage given prolonged exposure; we always practice with earplugs. So compared to a home stereo, this is really, really loud. Based on decibel charts I’ve seen, and the fact that you can feel the air moving and the vibration when you’re a couple of feet away, this is probably about 110dB.

A bit about units: decibels are logarithmic while watts are linear. That means that if my amp/speaker setup uses 220 watts of power and produces 110 dB of sound, and I want it to be twice as loud (120dB), I need ten times as much power.

Instead, what I learned by combining both amps together was that I really wanted less than twice as much power, which means about 3dB of additional volume. 3 dB is about the amount of difference in volume that is noticeable as “yeah that’s a little louder”.

So, I went looking for gear. Fortunately my needs are apparently common, and there’s a lot out there that would produce from 200-350W for my setup, and most of it is in the $1.1/W price range if bought in used condition. I ended up getting lucky, and ordering a new-in-box Crown XS 500 from eBay; it even comes with a warranty. The XS 500 delivers 400W per channel for my setup, and this one is costing me $338 including shipping (which was $40-$50 for similar items). So that’s about $298 without shipping for 400W, or $.745/W, and it comes with a warranty. Sweet!

That pushes the price of my rack up to almost $1000 total. Contrast that with, say, the Ampeg B4R, which has half the power of my rig, and nowhere near the features, and I feel like I’m definitely winning via the rack approach. By my $1.1/W metric, the Ampeg B4R delivers similar power to a $220 used power amp, but it costs $999 new. $5/W, ouch! Even with the preamp added in, that’s spendy.

Your choices about rack vs. all-in-one head may be different, but the rules still apply:

• Don’t underbuy power just because the manufacturer uses the most favorable situation to claim a high power rating. Woo hoo, 1200W! But that’s really for a 1Khz sine wave, using a bridged mono configuration into a 2ohm speaker load. Make sure you’re looking at the right numbers for your speakers (what signal, how many speakers, how many ohms?).
• Don’t underbuy power based on how many watts the vocal PA or guitar amp you’re playing onstage with has. You need much a more powerful amp to get the same perceived volume than your bandmates do.
• Don’t overbuy power due to a lack of understanding of how loud you need to be. Make sure you understand how the linear W / logarithmic dB relationship can tell you how much more power you want in order to be louder by a given amount.
• Don’t overbuy speakers (or underbuy an amp for speakers you already own) due to an overly conservative interpretation of power handling ratings. It’s not necessary to just match amp watts to speaker watts; a ratio of 1.5x-2x amp watts to speaker watts is safe, and as long as the signal coming out of the amp is clean (i.e. the amp isn’t clipping), the speakers will be fine. For more info, read this article.

I hope this helps you to put together a bass rig that sounds great and doesn’t break the bank, or at least to understand how to pick these components. Good luck!

P.S. Remember to practice! Everybody’s gonna hear your mistakes much more clearly when you have a clear, loud bass rig.

I realized today that I’ve read a whole lot about bass amplification over the years and had plenty of real world experience with different approaches, and I think this information is interesting to bass players at least, and probably rock music audiences and price/performance minded home audio enthusiasts too. So, I’ll start with some basic information about the state of live rock music amplification in Part 1, and then share some of my recently acquired knowledge with you in Part 2.

On the whole, rock musicians seem to be quite rational about selecting gear: it either sounds better, or it doesn’t. Except for carefully controlled studio environments, subtle nuances of tone at low volume don’t matter; the noise level in a live situation is pretty high. What matters is what you hear when everybody is amplified enough to be heard in conjunction with a live drum kit. So, I’ve never encountered anyone thinking like an audiophile and dragging a $250,000 4×10 guitar cabinet or $1200 guitar cable or $6000 platinum guitar pick around with their equipment to gigs.

Here are some examples of why there’s so much noise on stage. Put a drum kit anywhere near a bass amp, and the snare will rattle with every note and the toms will resonate slightly with each kick drum hit and with bass notes. Add a vocal mic and you’ve got a bit of everybody else’s sound on stage being picked up by that mic and amplified along with the vocals. It’s a mess. As a result, rock musicians tend to pay more attention to the subtle tone qualities of their instrument, and just buy amplification and speakers that do the job of making that great tone louder.

An exception is guitar preamplification: ever since the 60s, intentionally distorted guitar has been the norm, and that usually means the subtle and nuanced sound of vacuum tubes being overdriven like crazy, placed in between the guitar and the main amplification. The preamp and power amplifier are commonly combined in a single unit, but it is possible to buy physically separate preamps and power amps. So in this case, the amplification the musician chooses effects tone a lot.

An axiom of rock guitar is that it sounds better the louder it gets. Part of this is probably the nature of distortion (it really does sound very different when driven hard), but part of it is the psychoacoustic response that lets you perceive the same signal more clearly when it’s louder.

For bass players, that means that the wonderful pillowy yet crisply detailed tone you get from your 25 watt practice amp at home is going to get drowned out by the rusty jackhammer diesel chainsaw fine instrument that your guitarist so delicately wields. As a low frequency musician, you’re at a disadvantage due to physics: to achieve the same perceived loudness in the listener, you need to move more air, and that means more power shoving those chunky speaker cones around. For a handy real-world example, think of laptop speakers, a digital watch alarm, or a mobile phone ringtone. Tiny amounts of power can make really loud sounds out of a wimpy little speaker, if the frequency is sufficiently high. But if you want deep rumbling bass (such as the percussion in that hip hop ringtone, or the phat synth bass of a disco MP3 on your laptop), you need a lot more power.

That means that your gear is likely to cost more than you would expect. On the other hand, the guitarist has to spend a lot of additional money on a fancy preamp for tone reasons, while bass just sounds good naturally.

There are some corners that can be cut to get loud bass without actually spending big money. You can cut out all the midrange and treble frequencies, sacrificing detail and clarity to let the amp and speaker focus on driving the low notes. If you have a $200 bass, the thing probably sounds terrible anyway, so this isn’t really a sacrifice: the closer you get to a 100Hz sine wave, the better. But most bassists seem to be tone-obsessed, probably because of the fact that speedy flashy technique that sounds cool on a guitar or sax or violin or keyboard usually sounds terrible on bass (”where’d the bottom end go?”). So we aim to make a small number of important, valuable notes, and to make each one sound fantastic. (The guru of this style is Tony Levin, whose work you have almost certainly heard; go re-listen to Peter Gabriel’s “Sledgehammer” if you need an example of his mastery of the less-is-more approach.)

The other big corner that can be cut is in speaker cabinet construction. There’s an engineering trade-off that can be made between resonance and detail; consumer subwoofers lean heavily toward resonance at the cost of detail, and low end speaker cabinets do the same thing. You get a lot more low end rumble, but the precise attack of each note is lost in an auditory blur.

One very effective engineering trick that makes up for this is the use of “biamping”. That means that you use a crossover and two amplification channels, so low frequencies go into one amplifier channel which is connected to a big speaker in a boomy, resonant speaker cabinet. The other channel is midrange and highs only, and goes into a set of smaller speakers in a separate speaker cabinet. You get the clicky squeaky detail and the fat low end puddin’ all at once. It’s not very expensive to do this, so it’s a pretty common feature in bass amplifiers, and it’s what pretty much all computer speakers do: teeny speakers for detail, big boomy subwoofer for bass. For rock bass, it’s not too different. You just hook up two very dissimilar speaker cabinets (typically one with a single 15″ speaker and one with either two or four 10″ or 12″ speakers) and dial the crossover frequency knob until it sounds great. In my experience, 250-500Hz is the sweet spot.

Biamping is very effective, but it means you have to carry several big speaker cabinets around, and when used in conjunction with inexpensive low end speaker cabinets, it tends to lack “punch”; unlike a kick drum, there’s no “whump” at the beginning of each note. There’s just a “click” or “crack” from the high speaker; the “whump” gets lost in that cavernous low end speaker. The reason that’s undesirable is that the sound of each of your notes beginning is now trapped in the same frequency range as the guitarist’s low end, the snare drum, the toms, the singer, and the keyboard player’s right hand. That’s a crowded place in the mix, and it generally sounds pretty bad for the bass player to elbow in the midrange part of his sound where there’s already plenty going on.

So, if you don’t exercise good taste and tune your sound so that the band sounds good overall, which you really should be doing, your bandmates will do so. They’ll tell you to “turn down” and then “turn up the low end”, and then you’ll be back to providing puddin’ (which is why you have a place in the band in the first place), but without the detail that makes people dance and pay attention to your distinct and groovy bass part. So, given a fixed amount of power, biamping is better than not biamping, but it is still a pretty big trade-off.

So, what to do? Basically, buy more power. Instead of trading worse tone for more volume at a constant price, trade affordability for better tone. More on how to do that in Part 2.

If you’re on MySpace, please add tungstensf to your friends!

This is where my news, works in progress, and small works will be published for fun. Later on I’ll include a performance calendar (once I figure that out).

For now, I’ve posted all of my old odds and ends (song and song fragments) here with a nifty and simple Flash MP3 player. Let me know if this breaks for you; I haven’t tested it much yet but this setup beats the empty “coming soon” page I had here before today.

This is my final composition project for Music 233 at SFSU (Chromatic Analysis and Synthesis). The assignment was to write a piano and flute piece incorporating a specific overall form and a list of compositional techniques. I first came up with a harmonic structure (with general rhythm) that fulfilled all of the assignment’s requirements.

I recently watched Free to Be… You and Me on TVLand. So once I started to write a flute melody in a major key it was obvious to me that it should be written as if it were going to be in a children’s TV show.

mm. 1-8: the parade theme.
mm. 9-16: the description of what’ll be in the parade.
mm. 17-18: rain threatening to stop the parade.
mm. 19-24: the idea to take it all inside and have a carnival instead.
mm. 25-28: some fun indoors.
mm. 29-32: the discovery and announcement that the rain has stopped.
mm. 33-40: restatement of the parade theme, for the second try on having it outdoors.

(Note that the first and second sections each repeat once, so you hear mm. 1-16 twice then mm. 17-40 twice.)

This took about 12 hours from start to finish, from reading the assignment to compressing the MP3. The first part (harmony, and rhythmic and repeat structure) was done as scribbles on blank paper; the rest of the writing was done with Sibelius. There’s a PDF of the score.

This piece was performed (sight-read in front of the class) in the last meeting of the class on December 15th by pianist Emily Rubis and flutist David Roache. (Thanks!)

Download audio file (Critters_on_Parade-www.jamieflournoy.com.mp3)

Download audio file (My_Own_True_Love.mp3)

This is my final composition project for Music 232 at SFSU (Diatonic Analysis and Synthesis). The assignment included a simple melodic line and a fairly long list of required compositional devices. The harmony, voice leading, and rhythms are mine. There’s a PDF of the score which is what I turned in, and a MIDI version too.

This took me about seven and a half hours to write, including checking for errors, making sure voice leading was good, making sure all the required compositional elements were in there, adding all the analysis text under the staves, formatting it nicely, etc. Making a nice-sounding recording of it in GarageBand took about a half hour (mainly picking instruments and tweaking audio effects).

Download audio file (Mus_232_Composition.mp3)

As the title suggests, this is the first draft of a vocal pop tune intended for a female singer. This is the first song I’ve written that incorporates classical composition techniques I’ve learned at school, as well as being the first song I’ve written where the melody was designed to be sung rather than played.
The opening is a plagal cadence (destabilized by using inversions of iv-i instead of root position IV-I), which sets up Dm as the tonic. The verse uses Dm-C in a few different ways to lead into the V/III-III motion of C-F in the chorus, which initially returns to D but then repeats and follows a ii-V-I progression to F, the relative major of Dm. The coda follows an extended descending circle of fifths down to end on F.
It’s a work in progress: the voice leading could probably be better; there’s no bass line for most of the song; there aren’t any lyrics; the repeat structure as recorded isn’t what I intended. I’m happy so far, though.
I composed this in Sibelius 3 and then saved it as a MIDI file and imported it into Garage Band 2 which sounds much richer than the built-in Quicktime Musical Instruments that Sibelius uses.

Download audio file (Fem_Pop_Vox_1.mp3)

This is an attempt to answer the question, “can I make a locrian slap riff over a diminished chord sound like the tonic, and a major 7th chord a half step above sound dissonant, wanting to return to the diminished chord?” I think the answer is yes. Hah! This is the exact opposite of what I’m studying in school which says that diminished vii wants very badly to return to I. I made I want very badly to return to diminished vii.

This is also a big step forward for me because instead of stacking tons of parts on top of each other in the mixer (all playing at once), I tried to spread them out horizontally, over time. Suddenly a 17-second six-track loop turned into a 6 minute song. OK, not suddenly; it took five hours, most of which was tweaking. The slap bass loop is where it all began. The arpeggiated bass (that sounds like a jazz rhythm guitar part) was derived from that and evolved into the keyboard part. I’m particularly happy with the classic rock / heavy metal keyboard sound, so I decided to put it first. Changing the drum beat several times also made the looped parts sound more interesting, even though they themselves were unchanged.

Both bass parts were played on my Modulus Quantum 4-string bass. The melody was played in real time on my Roland A33 keyboard. There are still lots of things I would change (replace loops with variations; add at least one other progression; clean up the articulation of the melody part) but it’s not too bad as-is.

Download audio file (Hard_Driving_in_Moonlight.mp3)