Like many audio enthusiasts, the thrill of finding a hidden gem on platforms like Craigslist is irresistible. Just before last Christmas, I stumbled upon a pair of Pioneer CS-99A speakers for a mere $100. Despite having owned several speakers from Pioneer’s CS line in the past, and currently favoring larger Acoustic Research models and modified pro audio gear, the iconic look of the CS-99A always held a certain allure. This seemed like the perfect belated Christmas gift for my dad, and an opportunity to finally experience the 99As firsthand. While their condition was visibly worn with scuffed cabinets upon pickup in downtown NYC, all the original drivers were intact and functioning perfectly, stamped with the coveted “FB” mark.
The Restoration Process Unveiled
After bringing the speakers home, the restoration project began once the holiday rush subsided. My first step was reinforcing the structural integrity of the cabinets. I meticulously re-glued all interior seams to ensure an airtight seal, crucial for optimal performance, especially in sealed enclosure designs like the CS-99A. Next, I tackled the cosmetic restoration of the cabinets. Through a careful compound sanding process, I managed to revive the original veneer, salvaging it from its weathered state. While some minor nicks remain on the corners, these imperfections are negligible considering the incredible value of the find. A thorough polishing and application of tung oil brought the cabinets back to a near-original luster.
The most significant step in the restoration was the crossover recap, completed just recently. I replaced every capacitor within the crossovers with brand new, high-quality poly capacitors from Solden, Audyn, and Dayton, selecting the closest value matches to the original components. This recapping process is, in my opinion, essential for vintage speakers of this era. Many audiophiles criticize sealed speakers like the Pioneer CS-99A for lacking bass, often overlooking the critical factor of cabinet sealing and the degradation of original crossover components over decades. While the inherently smaller cabinet volume of the CS-99A does limit deep bass extension, there are effective ways to mitigate this. Beyond ensuring an airtight enclosure, I replaced the original fiberglass damping material with a generous amount of polyfil. This modern alternative not only improves damping but also eliminates the irritation associated with handling old fiberglass. With the cabinets reassembled and crossovers revitalized, it was finally time for the critical listening test.
Initial Listening Impressions in Detail
To evaluate the restored Pioneer CS-99A speakers, I set them up in my listening room, a 14’x18′ space with 9-foot ceilings, hardwood floors, and moderately reflective surfaces due to wall decor and paintings. Positioning was carefully considered: placed along the shorter wall, projecting lengthwise into the room, each speaker stood just over a foot from the back wall and two feet from the side walls, elevated two feet off the ground and facing straight ahead. Powering the speakers was my trusted Pioneer SX-828 receiver, connected with 14 gauge OFC speaker cable. For the initial listening source, I used my Thinkpad laptop equipped with a high-quality soundcard and Spotify Premium. While vinyl is my preferred listening format, digital streaming was more practical for late-night testing. As a young listener with trained ears, excellent pitch perception, and extensive experience in music production and room acoustics, I approached this evaluation with a critical ear.
Alt text: Pioneer CS-99A vintage speakers positioned in a home listening environment, showcasing their restored wood cabinets and classic design.
The first track chosen was Refugee by Tom Petty. Immediately, the efficiency and wide soundstage of the CS-99As were apparent. The midrange frequencies were remarkably present, while the bass, though controlled and tight, exhibited a degree of shyness in the lower registers. The treble was forward yet remained refined and polite, not becoming harsh. To further assess their low-end capabilities, I moved to a track with more substantial bass content.
For the second track, I selected Love of My Life by Santana. The standout characteristic continued to be the exceptionally clear and vibrant midrange. The crispness of the snare drum and the full-bodied guitar tones were notable. However, the bass remained veiled below 60Hz and exhibited a slight boominess around 250Hz. To address these frequency response nuances, I introduced an ART 31-band equalizer into the signal chain. I subtly attenuated the 200-315Hz range to tame the boominess and significantly boosted the frequencies at 50Hz and below, adding 6dB of gain at 31Hz. I also made minor adjustments to the higher frequencies, bringing back the 2000-2500Hz range by a few decibels and slightly lifting the bands at 10kHz and above for enhanced airiness.
Alt text: Detailed view of Pioneer CS-99A speaker drivers, emphasizing the distinctive “FB” stamp indicating original Foster-manufactured components, a hallmark of quality.
The third song in the listening session was Through the Eyes of Ruby by The Smashing Pumpkins. With the equalizer now in the mix, the transformation was dramatic. The initial impression was overwhelmingly positive – a night and day difference. By compensating for the speaker’s inherent limitations in my listening environment, particularly in the bass and upper treble regions, the sound became rich, full-range, and remarkably flat in perceived frequency response. The Pioneer CS-99As demonstrated an incredibly enjoyable presentation with a wide and immersive soundstage. The midrange detail was exceptional, and the horn-loaded tweeters delivered highs that were both crisp and smooth. The bass, once EQ was applied, became rich and authoritative, filling out the sonic spectrum beautifully.
Final Verdict: A Vintage Speaker Worth Rediscovering
Even with the crossover capacitors being newly installed and not yet fully broken in, the Pioneer CS-99A speakers have already exceeded my expectations. This model often receives undue criticism in online audio forums, and while the often-inflated prices they command on the used market may be debatable, at the price I paid, they are undeniably solid performers. My previously restored and slightly modified Pioneer CS-63DX speakers, which generally enjoy a better reputation among vintage audio enthusiasts, are, in my subjective opinion, not significantly superior in overall sound quality. The CS-63DX boasts larger cabinets and a higher-quality super tweeter, potentially reducing the need for equalization. However, the smaller CS-99A surprisingly features a woofer with a higher Xmax (maximum linear excursion), resulting in a warmer and potentially more impactful bass response. Furthermore, the midrange of the CS-99A seems more nuanced and detailed. Listening to Dire Straits’ Love Over Gold, the vibraphone was remarkably present, revealing subtle background details that I had never noticed before on other systems. The “FB” cones in the CS-99A may indeed contribute to a more pleasing overall tonal character, making the sonic comparison a close call. While the CS-63DX remains my personal favorite in the CS line due to its deeper bass and slightly more refined top end without EQ, the CS-99As are undoubtedly keepers when properly powered, positioned, and potentially EQ’d. Ultimately, I consider the two models to be very closely matched in overall performance. I am confident that my dad will be equally delighted with the restored Pioneer CS-99A speakers – a testament to the enduring quality of vintage audio.
