One of the younger speaker manufacturers around, PMC (Professional Monitor Company) was founded by ex-BBC engineers in 1990.

Unusually, and partly due to its re-invention of transmission line bass loading, it has had success in both ProAudio and hi-fi sectors.

Such loading requires constructing a long tunnel behind the bass driver, which would seem unlikely within the confines of a tiny (15.5x29x23.4cms) miniature, but the three-fold (four-section) line fitted inside this little enclosure has an effective length of an amazing 1.5 metres.

Improved design

This is the third time the DB1 (Dinky Box One) has been reviewed by us. We covered the original version back in 2003, when a pair cost £550.

Eighteen months later, we encountered the £625 per pair DB1+, which featured a better quality tweeter and crossover components.

Now there's been a further major revision and a further price hike. The price of this new DB1i has now jumped up to £825 per pair, but the speaker features substantial further improvements in all respects.

And whereas it was possible to purchase kits to upgrade a speaker from DB1 to DB1+, the DB1i changes are too extensive to make this possible.

Robust build

Almost everything about the new version is different. A new cabinet supplier has improved the quality, fit and finish of the enclosure.

PMC's own 140mm cast frame bass/mid driver has a stiffer, better damped 95mm paper cone and an improved voice coil. The crossover networks are pair-matched using high-quality components. But the most important change is a brand new 27mm soft fabric dome tweeter co-developed with Norwegian OEM driver specialist SEAS.

Finished in a choice of walnut, black ash, oak and cherry real wood veneers, the three internal partitions required to form the transmission line might make manufacture difficult, as does the complex recipe of damping materials, but it also ensures an exceptionally stiff enclosure.

Twin terminals facilitate bi-wiring or bi-amping and the rear panel also accommodates the large line exit slot plus an attachment plate for a substantial wall bracket.

Enthusiastic speaker system

Some wall reinforcement is clearly beneficial, with a gap of about 15cm between wall and speaker giving the best results under our test conditions.

The speaker's small size places obvious limitations on the ultimate bass weight, but the bass loading technique provides the DB1i with an impressive evenness, warmth and harmonic richness.

A major plus with the DB1i is that it has significantly more dynamic grip and enthusiasm than the average for speakers of this size and type. It's not dramatically better in this regard, but it does give it something of an edge in delivering an expressive and involving experience.

However, the overall tonal neutrality doesn't match a true monitor speaker. The DB1i's midband isn't the smoothest or most open midband and the presence dip is clearly audible on speech.

But music is a different matter and here it proves a fine communicator with very little boxiness and a notably sweet top end.