PMC DB1+ Passive Monitor Speakers Review

I bought my PMC DB1+ speakers to use as nearfields in my own design lab. So not only do I listen to a wide range of recorded material through these speakers but I also get to evaluate a wide range of audio hardware through them, so these speakers have been extensively trialled for nearfield use.

The DB1′s come in both passive and active versions and I bought the passive version as I already had a suitable stereo power amp.

DB1′s are the smallest in the PMC range of transmission-line monitors and combine a 140mm doped bass/mid range driver with a 27mm silk soft dome ferrofluid-cooled tweeter. The crossover unit works at 3kHz. Whilst I haven’t made use of the facility, the speakers can be bi-amped if desired. They are physically small, measuring only 290mm (H) x 155mm (W) x 234mm (D) but they do weigh quite a bit at 5kg per speaker, no doubt in part due to all that internal carpentry to form the transmission line.

Just as PMC claim you get an amazing low frequency response from these little ‘bookshelf’ speakers. The effective transmission line length is an amazing 1.5m, made possible by four internal folds and outlet vents at the top of the rear panel. I measured the low frequency response at approximately 3dB down at 50Hz and it then fell off at a rate of around 15dB per octave. The HF response is good to around 25kHz.

Stereo imaging is really great. Centre panned vocals are absolutely nailed to the centre spot which really helps with some of the mid/side processing I’m currently into. As with all nearfields it’s important to get them mounted at ear height otherwise the hi end drifts off into the distance very quickly. Due to the rear vented LF port I found it was absolutely essential to keep the speakers well away from walls otherwise LF boominess became very evident. I know this sounds counter intuitive as the LF from the rear port has to reach your ears to be effective, but believe me that bouncing LF off a nearby rear wall is not the way! At moderate listening volumes (I want to keep some of my hearing into old age!) the PMCs are untiring for long sessions but I found the mid range could get a little tiring after a while at higher listening levels with the speakers quite close to the listener in nearfield use.

To give DB1′s a review outing in a different listening environment, I brought them up to my main listening room and patched them in to my main monitor system in place of my (wonderful) B&W DM603 S3′s which made excellent temporary speaker stands for the PMCs!

I popped on some well recorded material comprising fretless bass, drums, two acoustic guitars plus lead and harmony vocals and gave the little PMCs a really critical listen and comparison with the much larger B&W floor standers.

First impressions were of very good clarity and fine detail reproduction. The DB1′s on the whole benefitted from being in a larger listening room. The bass has a very different timbre to that produced by the 603s but it would be wrong to say it was to any great extent inferior, just different. Considering the 603′s cabinet has 5 times the volume of the DB1′s and its useful bass extends about 10 Hz lower, the DB1 has an amazing bass reproduction for it’s size.

I still found the DB1′s a little tiring at higher listening levels even when I listened further away from the speakers, with the mid range getting a little conjested, but as I said earlier, at normal listening levels, this is not an issue.

The real difference between the speakers is the 603′s sense of space which the DB1′s can’t quite match, but remember I bought the DB1′s for nearfield use and in this respect they are close to ideal. As an example, the PMC DB1′s are perfect for picking out track detail in the mix. So maybe you have a difficult stereo guitar stem which you’re trying to balance within the main stereo mix. You really want to be able to hear small changes in level and maybe a panned delay/reverb effect. Really easy with these speakers.

If you require bass extension down to 50Hz then these speakers are highly recommended. Take note of the points concerning mounting positions and you will be delighted with these speakers.

Best features : Plenty of accurate bass, superb detail

Weakest points : can get a little tiring at high listening levels

Rating : 8/10

[info] www.pmc-speakers.com [/info]

Technical Specification

Available Finishes: Neo Black
Crossover Frequency: 3kHz
Dimensions: H 290mm 11.4″ W 155mm 6.1″ D 234mm 9.21″ (+6mm for grille)
Drive Units: LF Doped 140mm cast alloy chassis, HF 27mm, Silk soft dome, ferrofluid cooled
Effective ATL™ Length: 1.5m 4.92ft
Impedance: 8 Ohm nominal
Input Connectors: 2 Pairs 4mm Sockets (Bi-Wire or Bi-Amp)
Recommended Amp Power: 40-150WSensitivity: 87dB 1 W 1m
Useable Frequency Response: 50Hz-25kHz
Peak SPL @ 1M: 111dB
Weight: 5kg 11lbs