Toccata Grande, Part 1

By Lars Mytting
20 Jan 1998

Day one considerations

Family life can be very demanding for speaker building. And speaker building can be very demanding for family life. This is one of the reasons why this project took me so long. I wanted to make something experimental, and that requires a lot more time than building just another speaker using well-known techniques. Life is full of two-way speakers, so the aim was to make something else; a large speaker that traded some sound qualities while gaining on other.

This project was never meant to be a easy-assembly kit that would satisfy most tastes. It was intended as a area where I could try out several ideas. The name of the speaker reflects this. "Toccata" was originally the term for a stormy, experimental piece of music used by organ players when trying a new instrument. I can also promise that any organ toccata will be quite fun on the final speaker. "Grande" is simply thrown in to reflect the physical dimensions.

But I must warn the reader that the labour and complexity does not fully justify the final sound quality (my Nightingale speakers perform overall better) -- but the techniques and tricks here can be used in regular speakers with great benefit.

Design goal
When designing a speaker, it is a good idea to start with deciding what compromises the project must be subject to, and define what technical solutions these compromises will dictate. The goal for this speaker was stripped to one single feature, namely good transient response. Another word for it may be "dynamic contrast". A transient is a sound of short duration, and good transient response can only be achieved if the speaker can deliver its output fast and clean, without smearing the original sound, and be completely silent immediately after.

I think this is a crucial quality of a speaker, because the transients embodies a lot of the nerve and realism in sound reproduction. I like systems that really can reproduce the sharp smack from a snare drum, the drama and excitement from heavy notes on a piano, the attack of the human voice.

But no quality in a speaker comes alone. When you improve one thing in your speakers, it is rarely so that just one defined part of the sound gets better. If you can improve the midrange linearity, you will experience that both deep bass notes and small cymbals sound better. Often, we associate these instruments to "belong" to the bass driver and the tweeter, but there is no such analogy in real life. All instruments contain notes which extend far above and beneath their "average" frequency.

Likewise, if you get good transient response, you have also managed the speaker to have low compression, because the drivers must yield the full amount of SPL needed to reproduce the input signal, and a good cabinet, because wall resonances will smear the sound of a otherwise "clean" driver.

About the
author

Print this
article

Email this
article