| 4PI BUILD. [message #99885] |
Mon, 26 October 2026 06:23 |
camjuelz
Messages: 1
Registered: October 2026
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Esquire |
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This project has been roughly two years in the making, and I thought you might appreciate hearing a little about the journey, where I came from in audio, and how I arrived at your design.
First off, I want to tell you that these speakers sound absolutely incredible. They've exceeded my expectations, and after everything that went into building them, I couldn't be happier.
Where this all started
For quite some time, my main speakers were a pair of vintage Polk Audio RTA-12Cs. I've spent a considerable amount of time restoring and improving them, including refreshing their crossovers and replacing the tweeters with Polk's RDO194s.
I've always enjoyed those speakers. They produce a wonderfully big, rich, full-bodied sound, with impressive low-frequency extension for their age. They're very capable loudspeakers, and I've gotten a lot of enjoyment out of them.
But somewhere along the way, I started experimenting with something completely different: Altec Lansing 416-8B fifteen-inch woofers.
That experience changed my perspective on what I wanted from a loudspeaker.
The interesting thing was that my Altec setup wasn't particularly well executed. The cabinets weren't properly sealed, the backs were screwed on, the construction wasn't ideal, and the horns were sitting on top of the cabinets. It certainly wasn't what I'd consider a properly engineered finished system.
Despite all those shortcomings, there was something about the sound of those Altecs that I couldn't forget.
It was the realism.
The bass didn't simply sound deep or powerful. It sounded like a real instrument producing sound in the room. There was a physical presence, a sense of weight and naturalness, that my Polks reproduced differently.
The Polks sounded rich, deep and impressive, but the Altecs had this profoundly convincing quality to their bass that was difficult to describe until I experienced it myself.
That was a turning point for me. I started realizing that bass extension and bass realism weren't necessarily the same thing. I wasn't simply looking for more bass. I wanted better bass, and a more believable reproduction of the original performance.
Discovering and building the four Pi
That experience eventually led me further into high-efficiency loudspeakers, compression drivers, waveguides, crossover design and cabinet construction.
I spent an enormous amount of time learning about these things, much of which was completely new territory for me.
I initially explored possibilities involving my Altec drivers and your crossover design, but ultimately decided that if I was going to invest this much time, effort and money, I wanted to build the four Pi properly, using the drivers and design you intended.
I settled on the JBL 2226H woofers, B&C DE250 compression drivers, and your four Pi crossover and waveguide arrangement.
I also decided to have the cabinets professionally built rather than compromise on the woodworking. I wanted the dimensions, construction, bracing and internal damping to follow your design as closely as possible. Cherry veneer was my choice for the finish.
Along the way, I learned quite a bit about how much thought goes into a proper loudspeaker design. Cabinet volume, port tuning, bracing, damping, driver integration and crossover behavior all started making more sense to me.
I came to appreciate that a loudspeaker is much more than just a collection of excellent individual components.
There were also some frustrating moments.
My JBL woofers required attention, and for a while I thought I might need to completely recone them. I went through the process of sourcing repair components before finding a very knowledgeable technician who was able to repair the original drivers.
Fortunately, the original cones and moving assemblies were preserved, which I was very happy about.
After investing so much time into the project, getting those drivers sorted out and finally installing everything into the finished cabinets was an incredibly rewarding moment.
Finally hearing them
Now that I've actually had the opportunity to sit down and listen to the completed speakers, I understand much better what your design accomplishes.
The first thing that struck me was the naturalness of the presentation.
There is an effortless quality to the sound that I find difficult to describe. Instruments have real physical presence, voices sound believable, and the dynamics are simply outstanding.
The bass is especially interesting to me because it brings me right back to what originally attracted me to those Altec 416s.
Compared with my RTA-12Cs, the four Pis initially seem somewhat lighter in the bottom end. But the more I listen, the more I realize that what I'm hearing is a substantial reduction in the bloom and overhang I've become accustomed to with the Polks.
The bass is incredibly precise, controlled and authoritative. It has tremendous impact and slam without sounding exaggerated.
Interestingly, to my ears, the four Pis sound just as deep as the Polks in my room, but the character of that bass is completely different.
It's less about a big, rounded low-frequency presentation and more about hearing and feeling exactly what the instrument is doing.
That is precisely the quality I was looking for when I started this journey.
The midrange and high-frequency presentation have been equally impressive. There is exceptional clarity and detail, but the sound retains the natural, realistic character that I value so much.
I've also been experimenting with speaker positioning. Initially I had the cabinets facing straight ahead, but introducing roughly 30 degrees of toe-in made a substantial improvement.
The imaging became much more focused, with vocals appearing solidly centered in front of me. The soundstage seems much better organized, and voices have an almost tangible presence.
I've been using them for movies as well, and that has been another revelation. Dialogue is beautifully focused, effects have enormous dynamic impact, and the overall presentation is incredibly convincing.
My system consists of Audiolab 8200MB monoblocks and an SMSL VMV D1SE2 DAC. I've been experimenting with the DAC's digital filters, and the four Pis are revealing enough that those differences are quite apparent. With the Linear Fast filter, I particularly enjoy the additional sense of precision and definition without losing the naturalness of the speakers.
What this project has meant to me
Looking back, the most rewarding part of this entire experience has been how much I've learned.
When I started, I was primarily concerned with how deep a speaker could play, how much bass it could produce, and how impressive it sounded.
After living with the Altecs, experimenting with different equipment, studying your design and finally completing these four Pis, my priorities have changed considerably.
I've come to value realistic dynamics, proper tonal balance, controlled directivity, clean transient response and the physical believability of instruments.
The four Pis have brought those qualities together in a way I had been searching for.
What I find particularly satisfying is that they retain the big, effortless, realistic character that originally captivated me with the Altecs, but in a much more refined, focused and properly integrated loudspeaker system.
It's the kind of sound that makes me stop analyzing the equipment and simply enjoy the recording.
After two years of planning, researching, sourcing components, dealing with repairs and having the cabinets constructed, hearing everything come together has been a pretty incredible experience.
It certainly wasn't an inexpensive or effortless undertaking, but I can confidently say that it was worth every bit of it.
Wayne, I really just wanted to thank you for the work you've put into this design and for making so much technical information available to people like me who genuinely want to understand what makes a good loudspeaker.
Your four Pi design has given me something that I plan to enjoy for many years to come.
I'm very proud of what I've put together, and I thought you deserved to know just how much I appreciate the engineering behind it.
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