I wanted to share with you an extraordinary experience. As many of you know I have the rare privilege of owning a pair of speakers I have lusted over for much of my adult life. The Infinity IRS V, of which only 58 pair were ever made. I presented an entire video series on the building of Music Room One, the installation of these speakers (with a forklift) and setup. If you’d like to view the series, start with the last to make sure it’s something interesting. What’s freaked me out with these videos is the number of people viewing this last one, which now sits at 237,000. Why would a quarter of a million people watch a video on the IRS V? And because I used a snippet of a commercial track (Pink Floyd) the gods at YouTube forced me to place an ad in front of the video, for which I sincerely apologize to viewers for.
The journey with these magnificent beauties has been a long one and still there are miles to go. The room is not perfect (far from it in fact), the components of the speaker are aging, and my list of changes is long. Here’s a picture of the system from the video.
The first task had been completed some time ago. I replaced all the midrange drivers with new, hand built versions. The remaining tasks were many and I had not decided yet how to prioritize them when a listener pointed out to me the top end of the system seemed dull. We soon discovered the reason: the crossover components were dying, the capacitors in particular. This revelation helped my decision to tackle the crossover next.
The crossover inside the IRS V is crudely built. It sits underneath the massive wings, hot melted in place to the fiberglass base the midrange and tweeter sections sit on. It is more than thirty years old and the components are aging, in particular the capacitors. Instead of replacing the components piecemeal, I decided to rebuild it from scratch, as if I were involved in its original design, which I was not, but I knew who was. My good friend Arnie Nudell, the founder of Infinity, had designed these beauties back in the early 1980s and I went to him for advice. He explained that the quality of passive parts like capacitors and inductors is so much better today, as they were those many decades ago, that he would replace everything with state of the art components and proceeded to give me a list of what to buy.
With shopping list in hand I approached my chief engineer, Bob Stadtherr, about the project. Coincidently to this conversation it turns out Bob had decided to tackle select custom high end audio projects for Audiophiles in his spare time. So I hired him to design and build a new set of crossovers from scratch. My instructions were simple: no compromises. Bob went to town. My fellow IRSV owners got wind of what I was up to and jumped in without hesitation. Soon Bob was building multiple crossovers for IRSV owners on Saturday and Sunday and we all waited with high expectations.
When Bob tackles a project it is with all feet in and perfection is a given. It’s what he invests in PS Audio designs as well as whacky custom projects people who are fanatical about their high end systems ask him to build on his days off. My only stipulation with other IRS owners engaging Bob to build their crossovers was simple: just make sure I am first.
It’s good to be king. 
After a few months of work (there are only so many weekends he can contribute) my crossovers are finished and connected. The improvements are breath taking, I am still breaking in the new boxes, learning how different the speakers now sound, and getting adjusted to just how much of a difference passive components make in speakers. I knew they mattered, by am reeling from the degree to which they are improved. It is not like a new speaker, yet between what I was used to and what I have now, I doubt I would recognize them as the same.
One of the first decisions Bob made was to go external with the components. Instead of living in the midrange/tweeter panel bases, where they are subject to vibrations from the sound, he built custom boxes that sit behind the wings. And instead of the old non-polar electrolytic midrange capacitors Infinity used so many years ago, they were replaced with huge film versions. Bob then designed a custom circuit board and hand built each crossover into a true work of art. Below are pictures of what now the BHK Signature power amplifier happily drives.
I don’t yet know the true measure of these speakers. New passives need time to break in. But cold and out of the box, the system has taken an extraordinary leap forward and I am thrilled. Bob is now finishing the other crossovers anxious IRS owners are waiting for. I am always excited to see what miracles he helps people’s systems with, those lucky enough to engage him in custom work on their equipment, but for now I am the lucky one, enjoying what is essentially, a whole new system in Music Room One.
Thank you Bob. This is genius.
