Freq show

Computer Music - - Make Music Now -

Fil­ters are among the old­est elec­tronic au­dio ef­fects, dat­ing back to the ear­li­est days of tele­phony. A sta­ple of ra­dio pro­duc­tion in the early 20th cen­tury, prim­i­tive fil­ters usu­ally of­fered only a cou­ple of ‘tone’ con­trols, each with a fixed fre­quency (bass or tre­ble) and pre­de­ter­mined lev­els of gain con­trol.

If this de­scrip­tion smacks of the equaliser on your grand­dad’s old stereo hi-fi set, that’s be­cause it is. Hi-fi EQs use fil­ters ded­i­cated to spe­cific fre­quency ranges. Early stu­dios were more likely to have EQs in their racks than what we’d recog­nise as a fil­ter ef­fect with a sin­gle cut­off and res­o­nance con­trol. Yet the goal was the same: to take con­trol over spe­cific fre­quen­cies in the sig­nal path.

A few equalis­ers made a splash over the years, but none so much as the Pulse Tech­niques’ EQP-1a and its var­i­ous sib­lings, a de­vice with the pe­cu­liar abil­ity to si­mul­ta­ne­ously boost and cut at the same fre­quency. Dif­fer­ent curves for boost and cut al­low it to, for ex­am­ple, boost in the area around the cut­off fre­quency, while si­mul­ta­ne­ously notch­ing the area just above it. A favourite trick for bass drums when ap­plied to the 60Hz range, this tech­nique can add heft to the low end with­out mud­dy­ing the sig­nal.

You shall not pass

While early equalis­ers had much in com­mon with the ded­i­cated fil­ter ef­fects of to­day, it was Robert Moog’s 904a fil­ter mod­ule that had the most in­flu­ence over mod­ern de­signs.

De­signed for Moog’s mod­u­lar syn­the­siser sys­tems, the 904a is a low-pass res­o­nant fil­ter that al­lows con­trol over cut­off and res­o­nance, ei­ther man­u­ally or by means of in­com­ing volt­ages. A ‘4-pole’ de­sign with a steep rolloff, it could be driven into self-os­cil­la­tion by crank­ing up the res­o­nance.

Be­fore Moog (and his West Coast con­tem­po­rary Don­ald Buchla), elec­tronic mu­si­cians were forced to use sig­nal gen­er­a­tors and fil­ters de­signed for the lab­o­ra­tory. In­ter­est­ing work was done in this way (check out Bebe and Louis Bar­ron’s sound­track for

For­bid­denPlanet), but the equip­ment was cum­ber­some and could not be ‘played’ like a tra­di­tional in­stru­ment. To cre­ate in­de­pen­dent notes, mu­si­cians had to re­sort to cut­ting and splic­ing in­di­vid­ual snip­pets of mag­netic tape.

Elec­tronic pi­o­neers like Moog and Buchla changed all of that by in­tro­duc­ing sys­tems pur­pose-built for mak­ing mu­sic. Moog’s 1-volt­per-oc­tave tun­ing stan­dard and op­tional key­board at­tracted per­form­ing mu­si­cians to the world of elec­tronic mu­sic. Thanks to the suc­cess of his mod­u­lar sys­tem and the later self­con­tained Min­i­moog, the Moog fil­ter would be­come the stan­dard by which all oth­ers would be judged.

And there were in­deed oth­ers. the UK’s EMS chose a very dif­fer­ent fil­ter de­sign for their VCS3 syn­the­siser. Whereas Moog’s fil­ter was based on then-cut­ting-edge tran­sis­tor tech­nol­ogy, EMS built theirs around diodes. The re­sult was a less pre­cise fil­ter with a lively, squelchy char­ac­ter not en­tirely un­like that found on Roland’s TB-303 decades later.

Though th­ese fil­ters were in­cluded on synths, mu­si­cians like Pete Town­shend of The Who dis­cov­ered that they made keen ef­fects pro­ces­sors for ex­ter­nal gear as well, and soon they were wrapped around all man­ner of gui­tars, or­gans, drums and even voices.

By the mid-80s, Yamaha’s fil­ter-less DX7 was all the rage, and ana­logue synths had fallen out of favour. It would be an­other decade be­fore mu­si­cians and man­u­fac­tur­ers rekin­dled their love of the ana­logue fil­ter. The 1990s saw a few ded­i­cated fil­ters hit the shops, among them the wicked Mutron­ics Mu­ta­tor in 1996 and the lauded Sher­man Elec­tron­ics Fil­ter­bank a year later. By the end of the 1990s, the air­waves were rife with fil­tered drums and loops.

Need­less to say, to­day’s mu­si­cian has a wealth of fil­ters from which to choose, hard and soft. There can be few fil­ters of yore that have not been recre­ated ei­ther as a Euro­rack mod­ule and/or a soft­ware plugin.

A ma­jes­tic mono­lith, the fil­ter in Moog’s mod­u­lar mon­ster set the stage for decades to come

The Sher­man Fil­ter­bank was the weapon of choice for dec­i­mat­ing dance beats in the 90s and be­yond

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.