A811b-12
Introductory Price: $5,900.00
Original Price: $7,900.00
Our “big” sounding two-way: the power, scale, and room-filling presence of classic Altec horns — tuned for modern home listening. On top sits an original cast-aluminum Altec 811B horn. Down low, a fast 12" woofer in a rear-ported cabinet delivers punch and body.
SET & tube amplifier friendly by design.
97 dB sensitivity and an easy amplifier load bring the magic of low-power tubes with the scale of classic horn systems.
The goal is simple: real dynamics and effortless volume — music that feels like an event.
Sold as a pair
Built for
Medium to large rooms
Real music: jazz, rock, vocals, electronic, soundtracks
Anyone who loves Altec/JBL-style horn systems and wants true scale without needing a stadium
Why it sounds powerful and huge
The Altec 811B brings that unmistakable horn energy: big images, speed, presence, and air.
High sensitivity (97 dB) means it comes alive at low volume and stays clean when pushed.
>110 dB peak capability (pair, ~2 m)—when you want it loud, it’s loud and controlled.
Voiced for real rooms, not just perfect measurement setups.
Very Limited Production
We use original vintage Altec 811B horns—not replicas. And because there are only so many true originals left, A811B production is extremely limited and built in small batches as horns become available.
SET & Tube Amplifier Friendly
A811b-12 was designed from the beginning with low-power tube amplifiers in mind.
High sensitivity is only part of the story. Many speakers look efficient on paper but present difficult impedance loads that small tube amplifiers struggle to control.
Our crossover is carefully engineered to maintain an easy amplifier load, allowing SET and other tube designs to deliver their natural tone, dynamics, and presence.
With 97 dB sensitivity and a tube-friendly impedance curve, A811b-12 comes alive with just a few watts — while still having the scale and authority of a large loudspeaker.
Perfect match for:
300B • 2A3 • EL84 • EL34 • KT88 • low-power Class A amplifiers
Acoustic design
Type: 2-way, horn-loaded HF + vented 12" bass
Enclosure: bass-reflex with a rear-firing round port
Placement: 30–60 cm (12–24") from the rear wall, slight toe-in
Keep 20–30 cm+ clearance behind the port so it can breathe
Key Features
Drivers
High Frequency
Horn: Original Altec 811B, cast aluminum
Compression driver: 1” exit, 8 Ω
Coverage: ≈ 90° (H) × 40° (V)
Crossover region: ~1.1–1.2 kHz
Low Frequency / Midbass
12" woofer, 8 Ω
Covers bass and lower mids up to the crossover
Cabinet
Volume: ~80 liters per speaker
Material: 3/4 - 1 1/2 (18–36 mm) Baltic birch
Bracing: multi-plane internal bracing for low coloration
Damping: tuned (not over-stuffed) for speed and clarity
Port tuning: deep, controlled bass in the 34–38 Hz region
Dimensions (each speaker)
Width: 16" (≈ 406 mm)
Depth: 18" (≈ 457 mm)
Height: 33" (≈ 838 mm)
Weight: ≈ 35–40 kg (finish dependent)
Passive or Active
Passive
Custom 2-way crossover
Two voicings: Flat / Studio
Amp recommendation: 3–200 W/ch (tube or solid-state)
Optional Active
Built-in Hypex amplification + DSP
Separate amp channels for woofer and horn
Inputs: XLR / RCA
DSP: precise crossover, time alignment, Flat / Studio presets, room-tuning options
Simple setup: source / preamp / TV → speakers → done
Finishes
Standard: Walnut veneer
Custom veneers/finishes available on request
Furniture-grade hardwax oil finish
Grilles: optional, magnetic
What People Are Saying
“The Shakuto Audio speakers I auditioned were very detailed and had a great sense of depth and openness. They revealed a level of clarity and detail from lesser recordings that I don't normally hear, even on other excellent speakers. For instance, when listening to AJR's track, Bang! I heard details and dimensionality I have never heard from this song, which generally sounds pretty lifeless and two dimensional. The Shakuto Audio Speakers brought this song to life with a sense of dynamics and imaging I have never heard before. Another great track was Spinning Wheel by Blood Sweat and Tears, which had great attack and energy without the usual brashness I have heard on other systems. If you have an older, less than perfectly recorded collection, you will certainly appreciate the way Shakuto Audio will breathe new life into these beloved recordings. And well recorded music was even better: very open, detailed and dare I say, live-sounding! I can't wait to hear what's coming next from Shakuto Audio”
— Daniel Jordan, Audio Video Today,
“I had the pleasure of listening to a pair of Shakuto Audio speakers, and the experience was truly impressive. They produced an incredibly natural and detailed sound with beautiful imaging and effortless dynamics. The music felt alive in the room, making it a memorable listening experience.”
— Oren Pius, record store owner
“Shakuto did a custom build for our Cafe in LA. Serge was awesome to work with and the quality of the cabinet and port details were spot on. The finish work he did to the Altec 811b horns gave them a refined look and the gunmetal paint was impeccable. He provided progress pictures of the build and they looked even better in person. Serious craftsmanship by a team that obviously cares a lot. It was a pleasure working with him.”
— Philip Orosco, Betsy LA
Get in Touch
I'm Serge. I personally oversee every pair we build. Send me a message and I'll get back to you within a few hours.
All SHAKUTO Audio speakers are custom-built to order to ensure the highest level of quality.
Please allow approximately 8–10 weeks for production before shipment.