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Cambridge Soundworks SW1 and Slave Subwoofers Review

The CSW SW1 sub


The only good product by CSW?

Some say the Cambridge Soundworks' (CSW) SW1 Sub and Slave were the only good products the company ever made.  But some enthusiasts also grant such status to the original Ensemble system, which for a short time came with the SW1 and Slave subwoofers. Subsequent Ensemble systems used an inferior, smaller, 8-inch, ported woofer pair that was less powerful and more boomy than the acoustic-suspension (unported) SW1 and Slave subwoofers. CSW would sell a large variety of subwoofer designs over the next 20 years, but never again produced a speaker with the reputation among of audiophiles of the SW1 and Slave.

The back of the SW1.  Note level & lowpass filter panpots, and speaker level & pre-amp level in/outs

The back of the SW1. Note level & lowpass filter panpots, and speaker level & pre-amp level in/outs

Design Highlights

The SW1 and Slave are acoustic suspension designs.  This means there are no holes in the speaker cabinet, so a fixed amount of air is inside the box.  When the subwoofer's speaker cone moves in and out as it plays, therefore, air pressure inside the cabinet rises and falls.  This variable air pressure serves to damp the movement of the speaker cone, giving acoustic suspension speaker designs a "tight" sound and allows them to be generally more accurate than ported or passive radiator designs.

Few subwoofers are acoustic suspension designs.  Acoustic suspension designs, while more accurate, can't produce bass frequencies as well as ported designs can.  Most subwoofers are ported, meaning they have a hole - or port - which is sometimes "tuned" by having a tube of a certain length around the hole and extending into the subwoofer cabinet.  The hole allows air to move in and out of the cabinet as the woofer cone moves, and the tube allows only certain frequencies of sound to escape the cabinet, hence the "tuning" of the port. 

Since porting gives lower frequency response per dollar than acoustic suspension, most subwoofers are ported.  In the SW1 and Slave, CSW spared no expense and created a subwoofer with a flat frequency response curve that played LOW in a most intimidatingly musical way.  Subsequent CSW subs were ported and were by design boomy, like most subwoofers built today.

The SW1 and Slave are also special in the way power is supplied to each speaker.  The powered SW1 can be used on it's own, or it can power another cabinet and cone, the Slave.  Many subwoofers today are powered, but the Slave sub option is a great way to get right and left side subwoofers without overspending on low-end wattage.  The disadvantage to this design is for those who want to wire their pair of subs to reinforce the stereo image: the SW1 and Slave play a mono signal which is a combination of right and left channels (below the adjustable lowpass filter) or the subwoofer channel from a surround processor.

The Sound

The SW1 and Slave sound excellent. The acoustic suspension design gives them tight sound. With a little bit of placement experimentation and work on the level control, I found them to be excellent at reinforcing my main speakers. I use them to augment both stereo listening and home theater use. Every set of main speakers - except my Paradigm Studio Monitors - has benefited from the SW1 and Slave. That includes big, supposedly full-range floor-standing speakers like the McIntosh XR-14, Klipsch Heresey, and Bose 601. The Paradigm Studio Monitors don't benefit from the SW1 and Slave because they themselves are truly massive tri-ampable towers with twin 8" long-throw woofers and a tuned port in the back. They have subwoofers built in :)

I highly recommend purchasing these speakers if you can find the SW1 for less than $300 or the SW1 and Slave for less than $450.

Visit www.vintageaudiophile.com for more about vintage audio gear.


Mark Morgan on May 04, 2014:

This speaker reminds me of the old days when I used to have that speaker. Alas, that speaker broke when I had to shift my apartment. They were quite expensive but they were very good speakers. I loved their solid bass effect. It is quite hard to find these in a brand new state.

Richard Zentgraf on January 25, 2012:

I have some vintage Caimbridge speakers. I have a pair of beige Surround 2, 8 olms, right and left, numbered 24582 and 24583. I also have a Cambridge passive sub but there is no manufacturer name plate or markings. It looks exactly like the CSW SW1 pictured above. It differs though by the fact that the back is completely smooth. The speaker end of the woofer simply has a positive and negative indententation for speaker wire hookup. Can you be of any help placing a value on these items?

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