Tag Archives: woofer

Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

Opinions and experiences

I am not a fan of passive radiators in full-range speaker cabinets. In every instance, I was underwhelmed with the sound of their bass and blamed the common denominator, the passive radiator.

A passive radiator is a woofer without a motor. Just picture your favorite woofer cone and that’s how a passive radiator typically looks. Were you to take it out of the box you’d note its lack of magnet and its light weight. Radiators act as tuned ports, lowering the speaker’s bass frequency cutoff to below what just its active woofer can produce.

My opinion of passive radiators has been negative for years.

Our opinions are formed by our experiences. If every beet we eat makes our stomach turn just a little then we declare our dislike of beets. Likewise, if every passive radiator we hear is muddy and ill defined we reject anything resembling it.

That is until we taste a beet we like or hear a radiator done right.

Our speaker genius, Chris Brunhaver, has opened my eyes and ears to the delights of a properly designed passive radiator. And what’s fascinating to me is that it doesn’t even look like a woofer. In Chris’ design a piece of heavy material, like wood, is the cone and it’s held in place with a carefully engineered surround material. Together, they form a tuned circuit that is sonically invisible in the same way a proper subwoofer extends the apparent bass of the main speaker without pointing to itself.

Little woofers can have big, tight, low frequencies with a properly designed radiator.

The point of this post is more about how experiences form opinions and less about radiators.

When we have the opportunity to extend our knowledge and venture out into the unknown, we often return with new opinions that are to our benefit.

I just love being wrong.

 

Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

Building beasts

Building speakers is way different than electronics. For one thing, loudspeakers can be handcrafted and designed from scratch, where electronics require cobbling together off-the-shelf parts. No one in our industry is likely to invent new semiconductor physics and apply it to hand made transistors.

The opportunity to design and fabricate every single bit of a product and technology is really stimulating. When senior engineer Chris Brunhaver joined the PS Engineering Team his first task was to wipe the AN3 slate clean and start over. Why? Well, the simple answer is because we’re obsessed engineering nerds and he could. But I owe you a more detailed answer.

Take for example the 12″ servo woofer used in the AN3. In the prototypes we demonstrated at Axpona the maximum linear excursion of that woofer was less than what the 700 watt amplifier driving it could output. This required us to place carefully crafted dynamic limiters on the amp and its servo system so we wouldn’t exceed the woofer’s limits. Sure, it output prodigious bass, but we knew the system was capable of so much more. Scouring the multitude of catalogs from the world’s biggest driver manufacturers didn’t help. Finding that perfect combination of suspension, excursion, BL, voice coil capabilities, and so on proved fruitless.

There was no perfect woofer for our specific application, and why should there be? Driver manufacturers don’t build woofers with us in mind. They make the best general purpose drivers they know how to.

Then, Chris joined our engineering team. The first thing he did was put pen to paper and sketched out a massive new woofer that would not only handle every last watt the power amplifier could dish out but do so within a linear range. The resulting beast is breathtaking. Have a look at the frames being assembled as I write this.

Holy crap this thing is a monster! But, it’s our monster designed specifically for its intended purpose. Every bit of it—from the spider, suspension, cone material and dust cap to the way the lead wires are hand-sewn into the spider’s fabric so they don’t rattle—this beast is perfect for our application. Nothing else in the off-the-shelf-world can compete.

More to follow, but I wanted to share my excitement with you.

We’ll be demonstrating the next round of AN3 prototypes at the upcoming RMAF at the beginning of September.