LM Watts Technology Polyribbon

Name: LM Watts Technology Polyribbon
Brand: LM Watts Technology

Manufacturer:

LM Watts Technology

Model:

Polyribbon

Country of Manufacture:

United States

Microphone Type:

Ribbon

Polar Pattern:

Multi-Pattern

Production Start Year:

2015

Production End Year:

2023

Rarity:

Microphone History:

The Polyribbon was an ambitious multi-pattern ribbon microphone designed by the Leslie (Les) Watts, who had previously worked as a consultant for Shure and Electrovoice. The sale price at launch in 2016 was US$3850

Over a long career, Les designed heated mirrors for Jaguar cars, microphones and turntable phono cartridges for Shure, and for a time was head of R&D at ITW. Les sadly passed away in 2024. I had the honour of spending many hours on the phone with him discussing the Polyribbon and other microphones.

According to AEA's Wes Dooley, only four Polyribbons were completed and sold. The one featured here is from Wes's own collection, and two were sold to Blue Kite Studios in Istanbul in 2018, when they were used to record samples packs of drum sounds. If you are lucky enough to own a Polyribbon then we would love to hear from you.

Technical Description:

From the now defunct manufacturer's website (viewed via web.archive.org)

Figure 8, omnidirectional, and supercardioid switchable patterns
Mil spec finished aluminum and brass construction
Smooth 20 kiloHertz bandwidth
High output dual ribbon design
Custom designed High performance transformer
Three position bass rolloff
Supplied with measured response documentation
Hand crafted and individually voiced in USA

From a post by Les Watts in March 2013

"No variable pattern ribbon mics are made today but in the past RCA made the 77C,77D and 77DX and Western Electric/Altec made the 639 and 670. All these were either dual (pressure and velocity) ribbons, single ribbon with phase shift network, or ribbon velocity with dynamic pressure mic.

They all had problems. the dual ribbons and ribbon/dynamics had poor polar patterns in cardioid settings above about 3kHz due to the pressure section not being truly omnidirectional, but could be pretty good on figure 8 settings. The single ribbon/phase shift network type had better cardioid patterns but suffered in high frequency response due to the increased front to back path.

The RCA 77 series always had a huge response peak in the midrange (5kHz) in the pressure or omni settings.

All those mics were from a 10kHz world.

What we've done is a bit of a different approach. We have no midrange peak. That's solved. We've extended the frequency response to be as good as most condensers...but it doesn't sound like a condenser. The typical clinical sound of many condensers doesn't happen. A ribbon transducer can be inherently lower distortion than a condenser...and the often seen high frequency peak isn't there.

So the Polyribbon has extended response beyond 16kHz...but still has the ribbon character. And of course the bass is much much more extended compared to a gradient condenser or dynamic.

But doing this has not been easy! I guess that's why Harry F Olson and Bell Labs couldn't. But I have better materials and modern (laplace transform) network analysis...that helps"

The full electroacoustic design is below.