When these Pioneer CS-88a speakers came my way, I’ll admit, my expectations were low. They were essentially a freebie, thrown in with another audio equipment purchase – a casual “want these too?” followed by a “sure, why not?” Like many Japanese speakers from a certain era, they carried a somewhat unfair reputation. Terms like “Kabuki” speaker often come to mind, suggesting style over substance. However, curiosity, and perhaps a hint of optimism, led me to hook them up for a preliminary listen. My initial reaction? “Meh.” Typical tweeter foam rot, a woofer exhibiting voice coil rub, and to top it off, a dead super tweeter.
Yet, there were redeeming qualities. The cabinets were undeniably impressive, solid and substantial, hinting at a build quality that belied their initial sonic shortcomings. They felt heavy, suggesting decent components within. Perhaps, I thought, there was untapped potential waiting to be unleashed from these vintage Pioneer CS-88a speakers. So, I decided to invest in new capacitors and replacement foam surrounds, but like many projects, this one was relegated to the back burner for a while. Eventually, the day arrived to dust them off and embark on the restoration journey.
The first task was addressing the tweeter re-foaming. Thankfully, the tweeters themselves seemed to have survived the foam degradation relatively unscathed. After completing the re-foam, I reconnected them and this time, I gave them a more critical listen. My “meh” quickly morphed into “hmm, interesting.” These Pioneer CS-88a speakers possessed a surprisingly impressive midrange. It became clear that these weren’t speakers designed for booming rock music. Instead, they seemed tailored for more nuanced genres – jazz, classical, folk, and similar styles. They weren’t going to overwhelm you with bass, but they had a musicality, a swing, that was captivating. When listening to jazz legends like Miles Davis, you could truly feel the resonance of his horn.
The next crucial step in the Pioneer CS-88a restoration was the capacitor replacement, or “re-capping,” of the crossovers. Fortunately, the crossovers in the CS-88a are designed for easy removal, making the recap process relatively straightforward. The only real obstacle was the copious amount of glue Pioneer used in assembly. It was as if they had a stake in a glue factory and were determined to use up the entire inventory. Each crossover unit contained 1uf, 3uf, 5uf, 30uf, and 50uf capacitors. For the smaller value capacitors (1uf, 3uf, and 5uf), I opted for Dayton and Erse film capacitors. For the larger 30uf and 50uf values, I chose NPE (Non-Polarized Electrolytic) capacitors, as I wasn’t convinced that the significant extra cost of film capacitors for these larger values would translate into a proportionally significant sonic improvement in this particular restoration project. As the images illustrate, the original capacitors were not only glued down but seemingly glued into everything else around them. I carefully scraped away as much of the adhesive as possible, but left the remainder, knowing it wouldn’t negatively impact performance. Interestingly, upon measuring the removed capacitors, the larger ones showed significant drift, measuring roughly double their rated values (~55uf for the 30uf caps and over 100uf for the 50uf caps). The smaller capacitors were closer to their specified values, but still showed signs of aging. To finalize the crossover work, I installed new, modern speaker posts, a simple but worthwhile upgrade for improved connectivity.
Examining the internal cabinet construction, the photos reveal substantial cross-bracing. Notably, these Pioneer CS-88a speakers follow an older loudspeaker design philosophy, dispensing with internal stuffing or damping materials. This design choice is a characteristic of earlier speaker building traditions.
In a stroke of good fortune, I received invaluable assistance from a generous member of the AudioKarma community (who may choose to identify himself if he wishes). This member not only provided me with a functioning replacement super tweeter but also has a new woofer en route to replace the confirmed faulty driver. With these crucial replacement parts secured, I’m eagerly anticipating the opportunity to bring these restored Pioneer CS-88a speakers out of the basement and into my main listening space to truly evaluate their sonic capabilities. Overall, this Pioneer CS-88a restoration has been a rewarding project. I anticipate that to achieve their full potential, particularly in the lower frequencies, a subwoofer will likely be a necessary addition to the system. I hope to provide a follow-up report on their performance once they are fully operational and integrated into my listening setup, should there be interest from the community.
