Finding a pair of Pioneer CS-99A speakers on Craigslist for just $100 felt like striking gold, especially so close to Christmas. While these weren’t speakers I was actively searching for, having owned and experimented with various models in the Pioneer CS line, the allure of the CS-99A, particularly their distinctive appearance, was too strong to resist. My recent audio focus has leaned towards building custom speakers and working with larger format vintage models, but the CS-99A presented a perfect opportunity to find a unique gift for my father. Despite years of buying, selling, and listening to countless speakers, I had never personally owned a pair of 99As, always intrigued by their iconic design. Upon inspection in downtown NYC, they showed cosmetic wear, but crucially, all drivers were original and in working order, marked with the coveted FB stamps.
The Restoration Journey
Securing the Vintage Find
The initial pickup was straightforward, and after bringing the Pioneer CS-99A speakers home, they waited patiently on my porch. The holiday season kept me occupied, but once things calmed down, I was eager to begin the cabinet restoration.
Cabinet Refurbishment: Breathing New Life
My first step was reinforcing the structural integrity of the cabinets. I meticulously re-glued all internal seams to ensure they were completely airtight. This is a crucial step often overlooked in vintage speaker restoration. Next came the cosmetic work. I undertook a detailed compound sanding process, and fortunately, the original veneer proved salvageable. While some minor imperfections remain in the corners, these are negligible considering the initial price and overall condition. After sanding, I applied several coats of polishing and tung oil. The result was remarkable, bringing the cabinets back to a near-original luster.
Crossover Recapping: The Heart of the Revival
The most significant step, completed just recently, was recapping the crossovers of the Pioneer CS-99A. I replaced every electrolytic capacitor with new, high-quality polypropylene capacitors from brands like Solden, Audyn, and Dayton, selecting values that closely matched the originals. This component replacement is vital for vintage speakers, as capacitors degrade over time, impacting sound quality. Furthermore, I meticulously replaced every gasket on the enclosure seams. Many audiophiles criticize sealed speakers of this era for lacking bass, often failing to realize the extent of air leakage in decades-old enclosures.
Airtight Seal and Damping: Optimizing Bass Response
While the inherently small cabinet volume of the Pioneer CS-99A limits deep bass extension, several measures can enhance performance. Beyond ensuring an airtight seal, I replaced the original fiberglass damping material. Fiberglass, while common in older speakers, can degrade and release irritating fibers. I opted for a generous amount of modern polyfill. Polyfill not only avoids the irritation associated with fiberglass but also effectively dampens internal cabinet resonances, which can improve bass clarity and perceived depth. With the recapping and damping complete, the Pioneer CS-99A speakers were fully reassembled and ready for their first serious listening test in my space.
Early Listening Impressions
Testing Environment and Setup
The listening space is a 14’x18′ rectangular room with 9-foot ceilings, characterized as moderately live. Hardwood floors and walls adorned with paintings and decor contribute to the room’s acoustics. For this initial evaluation, the Pioneer CS-99A speakers were positioned along the shorter wall, projecting lengthwise into the room. Each speaker was placed just over a foot from the back wall and two feet from the side walls, standing two feet off the ground and facing straight ahead. Powering the speakers is a vintage Pioneer SX 828 receiver, connected with 14 gauge oxygen-free copper (OFC) speaker cable. The music source was my Thinkpad laptop utilizing a high-quality soundcard and Spotify Premium for convenience. Volume levels were kept low on both the software and the amplifier for initial testing. While vinyl is typically my preferred listening format, it wasn’t practical for this late-night session. As a younger listener with trained ears, acute pitch perception, and extensive experience in music production and room equalization, I consider myself to have a critical and discerning ear.
Initial Auditory Assessment
First Song: Tom Petty’s “Refugee”
My first impression was immediately positive. The Pioneer CS-99A speakers demonstrated impressive efficiency and a wide soundstage. The midrange frequencies were noticeably present and detailed right away. Bass response was controlled and tight but clearly shy in the lower registers, reluctant to extend deeply. Treble frequencies were forward but remained smooth and polite, avoiding harshness. To further assess their capabilities, I selected a track with more demanding low-end content.
Second Song: Santana’s “Love of My Life”
“Love of My Life” by Santana further highlighted the strengths and weaknesses of the Pioneer CS-99A in their initial state. The midrange remained exceptionally clear and live, bringing out the nuances of the crunchy snare drum and the full-bodied electric guitar. However, the bass still felt veiled below 60Hz and exhibited a slight boominess in the 250Hz region. To address these sonic imbalances, I decided to introduce an equalizer into the signal chain.
Equalization Magic: Fine-Tuning the Sound
To compensate for the observed frequency response limitations, I employed an ART 31-band equalizer. I subtly attenuated the 200-315Hz range to tame the boominess and significantly boosted the frequencies at 50Hz and below, ultimately adding 6 decibels of gain at 31Hz. Additionally, I slightly enhanced the 2000 and 2500Hz bands and gently lifted the 10kHz and higher frequencies to add a touch more air and sparkle.
Transformed Listening Experience
Third Song: Smashing Pumpkins’ “Through the Eyes of Ruby”
With the equalizer engaged, the transformation was dramatic. My immediate reaction was pure satisfaction. The difference was night and day. By precisely compensating for the Pioneer CS-99A’s inherent tonal tendencies within my listening environment, the sound became rich, full-range, and remarkably flat. The Pioneer CS-99A speakers now presented an exceptionally enjoyable listening experience, characterized by a wide and immersive soundstage. The midrange detail was truly outstanding, and the highs, despite being horn-loaded, remained crisp and refined. The bass, once properly balanced with equalization, became rich and authoritative.
Final Verdict and Comparison
Even in their early hours post-restoration, the Pioneer CS-99A speakers have exceeded my expectations. I anticipate further sonic improvements as the new capacitors break in over time. This model often receives undue criticism, and while the inflated prices sometimes asked for them may be questionable, at the price I paid, they represent exceptional value and solid performance. My previously restored and subtly upgraded Pioneer CS-63DX speakers, which enjoy a more favorable reputation, are arguably not significantly superior performers in direct comparison. The CS-63DX boasts larger cabinets and a higher-quality super tweeter, reducing the need for equalization. However, the smaller CS-99A features a woofer with a notably higher Xmax and delivers a warmer bass character. The midrange on the CS-99A also seems more nuanced and detailed. Listening to Dire Straits’ “Love Over Gold,” the vibraphone is remarkably present, revealing subtle background elements I had previously missed. The FB cones in the CS-99A may indeed contribute to a more pleasing overall tone, making it a very close call between the two models. While the CS-63DX remains my personal favorite in the CS line, primarily due to its deeper bass and slightly more refined top end, the Pioneer CS-99A speakers are undeniable keepers when properly powered, positioned, and, if necessary, equalized. Ultimately, I would consider them a tie in terms of overall sound quality and enjoyment. I am confident my father will be equally delighted with this vintage audio gem.
