“Olaf” - woofer base for any speaker

Olaf woofers with Ellis 1801s on top.

There is a huge variety of small to medium size, predominantly two-way speakers on the market today. Most of them share excellent coherence, precise imaging and good transient response. However, even the best of them share several common problems:

  • They need to be mounted on some kind of sturdy stand
  • They lack the last one, and often even two octaves of low-end bass.

In our opinion, a speaker system, which cannot reproduce the foundation of music, is incomplete. Now there is no excuse for it:

Enter VB Speakers’ answer to these problems

The goals:

We decided to design a woofer speaker, to provide the foundation of a full-size audio system, in every sense of the word: both structurally and acoustically. These speakers are not sub-woofers. They are meant to be used in pairs (for a stereo set-up), so they had to be able to accurately reproduce signals up to 300 Hz. At the same time, they had to reach down to below 20 Hz with enough authority even for a large room. The base was to be fast and tightly controlled, with accurate transients and no overhang.

The best way to achieve these goals in our opinion is an active, powered speaker system with closed box acoustical alignment, line-level crossover and equalization and direct coupling between the woofer and the amp. It also should provide sufficient adjustments to match to the monitor speaker above and to the room around.

The driver:

Olaf is designed around a phenomenal woofer - SEAS L26ROY from Norway. The Scandinavian origins of this driver are reflected in the name of this speaker.

This is a 10” woofer with an extremely light (only 107 grams) and rigid Aluminum cone, absolutely huge magnet and large ventilation openings. The large motor however offers very low inductance and a low level of distortion. It is capable of an astounding 28mm of linear peak-to-peak travel, with mechanical limits being twice that much again.

Inside

Double walls (Baltic Birch plywood + MDF) with constrained-layer damping, bracing, isolated compartment for the VB1 amp.

The VB1 Crossover / amplifier /Linkwitz Transform

This unique device was co-developed with and is manufactured by Marchand Electronics.

The amp provides 300 W of honest Class AB power. Due to the size of the transformer and power supply, the amplifier can output quite a bit more in a short peak. It is biased relatively high for lowest distortion. It contains 4th order LR 2-way Crossover with 12 frequencies, selectable by a switch (40 to 320 Hz). You also get separate volume control for hi-pass and low-pass (also 12 position switch each) and the Q-factor at the XO point. In addition, there is fully controllable Linkwitz Transform for the low-pass channel. The phase between hi-pass and low-pass is adjustable within 180º.

The mains voltage and frequency are selectable by a switch, but one has to install the appropriate rating fuse. Finally, there is a switch, which lets you bypass XO, or LT, or both.

Linkwitz Transform

Linkwitz Transform (http://www.marchandelec.com/wm8.html) is a specialized low-frequency equalizer. It works by creating a precise equalization curve to compensate for the resonance of the driver in its current enclosure, thereby providing new Fc and Qtc for that system.

Here is how it looks in the Olaf:

 

The yellow line is the response of the driver without LT. Other curves correspond to different Qtc of the system and show what is possible to achieve.

The roll-off to the high-frequencies is the work of the active crossover, set to 200 Hz.

Olafs can be used with any other speaker, not just Troika

Options: 
  1. Amp input and output: balanced or RCA, can be selected separately at the time of order
  2. Any wood veneer in the world (although it may result in a longer lead time)
  3. Finishes:
    • a. Stain, Poly
    • b. Stain, pre-catalyzed lacquer
    • c. Oil finish, wax (our favorite)
  4. Footers:
    • a. Outriggers
    • b. Spikes
    • c. Herbie’s Dots, gliders, etc…
  5. Your choice of binding posts, although big Cardas are recommended

 

Pricing: 

The MSRP of the pair of Olafs is $8500.00 The single speaker for a multi-channel set, or to use as a sub-woofer - $4250.00