At low frequency, our hearing may not be that sensitive to distortion since the wavelength is so long. At low frequency, what's more important is how well the bass is properly damped - otherwise the bass will be lose or flabby. Two most important variables that determine the quality of the bass is first the driver QTS, and the internal volume of the cabinet. As for how low the driver can go determined by first the size of the driver surface area, secondly the material (such as paper, aluminum, ceramic ...), and thirdly the Xmax (or how much excursion can the driver move back and forth). In general, everything else being equal, the harder the cone material, the more bass extension. Hence materials such as aluminum, kevlar or magnesium will have more bass than paper cone.
I think the Harbeth 30 woofer is made of paper or paper that has been coated with some sort of material. The Pulsar woofer is magnesium, so most likely it will have more bass extension vs. the Harbeth. I personally have used the Seas 5.5in magnesium, and I would crank up the volume and that thing would just play on. I did the same thing on a lesser paper cone driver it broke on me.
The challenge in designing small monitor such as the Pulsar is that you need some sizable internal volume to able to control or dampen the bass. But most people want small monitors so that they look pretty in their living rooms. If the internal volume is too small, you have a midbass hump. For the magnesium woofer on the Pulsar, you probably need about 13 - 15 liter of volume to properly damp the bass output. I've read the Stereophile review and it seems like the Pulsars do have a bit of a midbass hump. The midbass hump sometimes can be mistaken for having deeper bass. And to be fair, most monitors in the same size category as the Pulsars probably don't have much deep bass to speak of so it's more like a game of millimeter.
I think the Harbeth 30 woofer is made of paper or paper that has been coated with some sort of material. The Pulsar woofer is magnesium, so most likely it will have more bass extension vs. the Harbeth. I personally have used the Seas 5.5in magnesium, and I would crank up the volume and that thing would just play on. I did the same thing on a lesser paper cone driver it broke on me.
The challenge in designing small monitor such as the Pulsar is that you need some sizable internal volume to able to control or dampen the bass. But most people want small monitors so that they look pretty in their living rooms. If the internal volume is too small, you have a midbass hump. For the magnesium woofer on the Pulsar, you probably need about 13 - 15 liter of volume to properly damp the bass output. I've read the Stereophile review and it seems like the Pulsars do have a bit of a midbass hump. The midbass hump sometimes can be mistaken for having deeper bass. And to be fair, most monitors in the same size category as the Pulsars probably don't have much deep bass to speak of so it's more like a game of millimeter.