Roy #2

After the success of the Roy 1, a friend requested a new pair of speakers at a very low budget of fifty dollars. Some parts were recycled from the Roy 1 in order to reduce costs to meet this budget. I finally started to use simulation tools properly so this was my first attempt using these tools.

Driver Selection

A 5 inch Dayton paper woofer from China and recycled Audax titanium dome tweeters were used. The Audax titanium dome tweeters were very delicate with an exposed titanium dome. They had a lively, bright sound perhaps too bright, yet implementation is definitely the key to their success. The woofer was selected for budget reasons and for something that could be easily driven by a 6 watt T-amp.

Crossover Design

Second order crossovers were used on both the woofer and the tweeter. Additionally, there was a zobel notch filter to control the rise in impedance for the woofer.

Other than a slight rise in the treble above 10 KHz, which most people would not notice, the speaker is smooth, especially under the woofer's passband. The dip between 3 and 6 KHz is fine, as the ear is sensitive to sound in this region and a very bright room can make speakers flat in this region sound terrible. Nevertheless, though the graph appears fine at first glance, there is one very large problem - the tweeter is crossed over far too low. This results in a large amount of distortion when the volume is high. Thus, this speaker was never much pleasurable to listen to, nor even good to look at. A new speaker was built later on.