Vifa Premium Line Monitors

6.5 inch 2-way

by Michael Chua

Measurements by LMS version 3.0
LMS is manufactured by LinearX

This design is free for DIY. Not for Commercial Use.
This article may not be published in part or full without the express permission of AmpsLab.

VIFA PL18WO-09 & PL27TG-35

As some of you may be aware, Vifa is no longer manufacturing these components. This is quite a pity as I found them to be exceedingly good value for money. Over the last 10 years, I have worked extensively on them in various configurations, from a minimalist 1st order to complex 4th order networks. This article shows what can be achieved with these under-rated but outstanding components when cost is not an objection.

This design is based on the following:

Compact 0.64 cu ft (18 Liters) Vented Box
Fourth Order (24dB/Oct) Linkwitz-Riley Network
Crossover Frequency of 1,500Hz

Yes, it's not a typo error. The tweeter is indeed crossed at a demanding 1,500Hz. I settled on this frequency simply because after much trial and error over the years, this is where it sounds best. Generally, this Premium Line tweeter is more comfortable when crossed between 2,500 to 4,000Hz but it has never impressed me at that region. In designing speakers, what is of paramount importance to me is for instruments to have the right timbre. To achieve this, I had to take this 1" Silk Dome tweeter down to a low of 1,500Hz, into the realm of compression drivers. In fact, I initially took it farther down to 1,250Hz but there were some protests from the poor gal.

For the woofer, the Vifa PL18 is chosen for its ability to go down fairly low in a compact box. Sub bass is not my target. Mid-range transparency, the right Timbre and a tight, dynamic Bass are the sonic objectives I strive for. A feature that these components have in common is their relatively flat frequency responses (or so it seems) and a decent looking rolloff.

Before we proceed to box modeling, let's take some measurements to determine the Thiele & Small Parameters of the PL18 woofer.

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