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Q.

How can I assign modulation to filter cutoff on my Akai S2000?

I am trying to set up my Yamaha CS1x to operate my Akai S2000 sampler, but I cannot operate the S2000's filter using the mod wheel on the CS1x. I can modulate the filter using the pitch-bend wheel but this really isn't the best solution, and since I have no other keyboard with a mod wheel, I don't know whether the problem lies with the keyboard or the sampler. I have tried everything, but nothing seems to work, even though the sampler is receiving some information from the mod wheel.

Tom Owen

via email

Paul Sellars replies: Akai's S2000, S3000XL and S3200XL samplers make use of what the company call 'Assignable Program Modulation' (APM), which allows a considerable amount of flexibility when choosing modulation sources for a program. Under Single / Edit (or, if you're dealing with a Multi Part rather than a single Program, Multi / Edit) two pages below the main Filter page, you will find the first of three 'FILTER MOD' pages. The default setting of 'FILTER MOD 1' will be 'Veloc. +00'. Press the F1 key to move the cursor from the '+00' field to the field where 'Veloc.' (velocity) is displayed, and turn the data wheel to the left until 'Modwhl' (modulation wheel) is displayed. Now press F2 to move the cursor back on '+00', and change the value to whatever suits you ( a range of -50 to +50 is available). Provided your CS1x's modulation wheel is sending nothing other than standard modulation data, you should now be able to adjust filter cutoff by moving the mod wheel, or by writing modulation messages into your sequence.

Another good tip for using APM is to set the modulation field to 'Externl' (external) and then, on the 'Ext APM control' page under the 'Global' menu, choose 'BREATH' as the external control source. This allows you to use breath-controller messages (controller number 2) to modulate filter cutoff. The great advantage of doing it this way is that it enables you to tweak filter cutoff without having to sacrifice a controller, such as modulation, which is potentially very useful in other respects. Certain controller keyboards, such as Roland's inexpensive PC200 MkII, have an assignable data-entry slider which can be set to send breath-controller messages, thus acting as a dedicated filter-cutoff control. Very handy -- provided you're not one of the three people left in the world who actually need to use a real breath controller! *

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Q.

Which would be the best set of mics for recording a wind band?

What do you suggest would be the best set of mics for recording a wind band? The mics available are two unidirectional capacitors, two omnidirectional capacitors, and four cardioid dynamic mics.

Geoff Rowlands

via email

Technical Editor Hugh Robjohns replies: I appreciate your problem, but it is a little like asking whether you should buy a hatchback, saloon or estate car! The answer, I'm afraid, has to be 'it depends...' With careful listening and skilful placement, it should be possible to produce equally good results with all of the three options you suggest.

With only two to four mics, close-miking techniques are obviously out, and I wouldn't have recommended them anyway: the sound of brass instruments needs a little space to develop. Distant miking requires a reasonably good-sounding acoustic in which to perform, and I assume you have somewhere suitable in mind. A wooden-floored room, ideally with wood-panelled walls, is often very good for brass: the warmer reverb works well with a bright brass sound.

You could try a pair of spaced omnis, say 8-10 feet apart, depending on the size of the band; the mics need to be about half the width of the group apart, but experiment with positioning. The problem is going to be balancing the perspective -- getting the correct amount of room acoustic with the band, without favouring any specific instrument too much. Using cardioids allows you to move further back while getting the same stereo perspective, which also helps to give a more uniform balance to the band.

Spaced mics tend to give a rather vague stereo image, and I personally prefer crossed-mic techniques; this ties you to the cardioids. Experiment with the mutual angle of the mics to get the correct stereo width and balance. If the band sounds very bright and raspy the dynamic mics might give a fuller, more controlled sound, but in general I'd go for the capacitor mics every time. *

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Q.

Can I get a cheap, basic computer to record audio?

I don't own a computer -- I just use the public library's -- but I want to 'upgrade' from my cassette 4-track and stand-alone sequencer setup. Is it possible to buy (perhaps second-hand?) a computer that could have, at least eight mono tracks of CD-quality audio, that could record two or more of them at a time and run, say, twice as many MIDI tracks, or at least sync them to my existing sequencer? I read so much about three- or even four-figure PCs that do all-singing, all-dancing 48 tracks and plug-ins and everything, but I'm too poor and too modest in my musical endeavours to warrant such luxury! Besides, I have a 'small-toolbox' theory when it comes to creative ventures...

I also have good access to an 8-channel desk, the usual outboard gear and plenty of microphones, plus a DAT!

Denis McDermott

via email

Assistant Editor Sam Inglis replies: Even a very modest PC these days would be capable of running eight mono audio tracks alongside 16 channels' worth of MIDI data; you should be able to pick up a suitable machine new or second-hand for £300 or less, though you will need to budget for suitable software too (the entry-level versions of packages such as Cubase and Logic Audio are good value). Check out SOS readers' ads, the second-hand ads in you local paper, or budget computer retailers.

However, if you're planning to use the computer solely as a recorder and do all your mixing and effects processing externally, be warned that unless you fit a high-end soundcard (which may not be possible in an older PC) you're unlikely to have eight separate outputs. Most cheap soundcards (and factory-specification Macs) have only stereo outputs, meaning you'll have to mix down your eight tracks to stereo on the computer, rather than having each track go into the desk on a separate channel. This would obviously make it hard to apply external effects to individual tracks at mixdown; if you're concerned about this, it might be worth looking at an eight-track digital recorder such as the Fostex VR800 plus VC8 converter box, or a second-hand Alesis ADAT, instead of a computer. *

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Q.

What's causing our PC audio glitches?

We recently upgraded our studio computer to a Pentium II 400MHz machine with 100MHz buss, 64Mb of RAM and a Yamaha 6416 CD writer. The graphics card is a Verge S3, and on moving the windows' scroll bars, clicks and crackles and pops occur in our audio. Even when these bars are not being moved, the recording suffers from the same problems. We have altered the Graphics Hardware Accelerator to minimum, altered DMA buffer sizes and memory per channel -- all the settings recommended in the manual -- but with no resolution. If you can be of any help, we would be grateful as we are at our wits' end!

Paul Stokes

via email

Martin Walker replies: While you are on the right track with reducing the Graphics Hardware Acceleration from its default maximum setting, the big clue comes from your make of graphics card. The S3 chipset used in your Verge is well known for causing problems due to 'buss throttling'. Originally brought to musicians' attention by Greg Hanssen of Zefiro Acoustics, this has caused countless problems over the last few years, and happens when graphics-card drivers are written in an inconsiderate way which allows them to completely take over the PCI buss whenever they feel like it. While this approach gives marginally faster graphic performance, and causes few problems for mainstream users, any interruption of the PCI buss during recording or playback of digital audio files will cause dropouts, giving rise to the clicks and pops that you are experiencing.

The classic test for such problems is to play back a WAV file from your chosen application running in a small (ie. not maximised) window. Then grab the title bar, pick up the window, and drop it elsewhere on the screen. You may get clicks and pops while you drag or when you finally drop the window, and in some cases the left and right channels may also get permanently swapped over after the drop. Although this problem originally seemed insurmountable with some graphics cards, most of the latest drivers allow you to disable this antisocial activity. Where there is a solution (there isn't always one), each make and model of card needs a slightly different approach, ranging from unchecking tick boxes labelled 'PCI Buss Retries' to disabling Buss Mastering.

S3-based graphics cards like yours can be fixed by manually adding a line to your System.ini file. You can find this in the Windows folder, and open it using the Notepad utility. Look for a section headed [display], and under this type 'bus-throttle=1'. Don't worry if your System.ini file doesn't have a [display] section -- if there isn't one you can simply add both lines to the end of the file. This fix apparently works with both Windows 95 and Windows 98, though it only works for graphics cards with S3 chipsets, so don't bother adding this otherwise.

Incidentally, you can often narrow down audio glitch problems relating to the graphics card by noticing when and where they happen. As well as on moving the scroll bars, you can sometimes get problems when the screen redraws (when the cursor has scrolled to the right-hand side of the screen) or even when opening a dialogue box. This may indicate buss throttling, but may also simply mean that you are running 'close to the edge' of your computer's processor capability. At this point, suddenly asking for more graphics to be plotted on screen pushes the overhead over 100 percent; the problem will disappear if you run fewer audio tracks or real-time plug-ins. *

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Q.

To heat or not to heat?

I recently experienced the pleasure of moving into a flat with enough rooms that I could dedicate a whole room (albeit a small one) to my studio for the first time. I work full-time and only use the studio on days off, which means the room is barely occupied for a few hours a week. At present I have switched off the heating in the room except on days I intend to use it, but have found in recent weeks that the temperature drops considerably compared to the rest of the flat. Is it unhealthy for the equipment to be in a room which changes temperature several times a day (if the heating were left on) or am I putting it at more risk by letting it get very cold? Also, the other night I saw a lot of condensation on the window -- that can't be good, can it?

All of my gear is electronic: there are no guitars or drums, just sequencers, modules, a mixer, monitors, recorders and lots of wires. So, do you think I should leave the heating on or off?

Max Duley

via email

Editor Paul White replies: Condensation is bad news, as it can cause damage to components and metal parts, but lowish temperatures shouldn't be a problem if the air is dry. I suggest you buy yourself a floor-standing dehumidifier and leave it on permanently in your studio. Mine shifts about a gallon of water every two days, and the studio isn't even damp! It also tends to make the room feel a little warmer. It'll be a couple of hundred quid well spent -- it's a small price to pay to protect your equipment. *