It's cold and windy outside, I'm bored, my hands are itching to do something, so here I am.
The psb Alpha B1 are my first "decent" speakers, purchased at a retail price of $299 CAD/pr. Needless to say that I have long outgrown them in the ten years since, and I'm fed up with trying to offload them through my local classifieds, so here I am ripping them apart.
I am not a speaker reviewer by any means.
Overview
Yes I took this picture after having removed the screws. There was also a metal mesh grille on this speaker that couldn't be removed normally: I pried them off using a thin flathead screwdriver.
The first thing that struck me (and probably you too) is how close the tweeter and woofer are placed together. The second thing that struck me is how recessed they are into the front baffle. See that curved lip up top? Well it's the same thing at the bottom, and the grille is curved to conform to that. There are also raised lips on the straight sides. Diffraction central? You be the judge. All I know is the sound quality of these speakers fall the heck apart when I try to play them at rock-out levels.
Also I have no idea why there is an array of dimples up top where the tweeter is. Some manufacturers put dimples into their tweeter waveguides though is this clearly not the case here.
Tweeter
This is a one-inch unit. psb calls it "aluminium dome". Yeah, uh, it's not. It looks like a silk unit with a metallic coating. The surround looks to be part of the driver's weave.
The... triangular diffuser looks more like something designed to dampen/smother the treble. It's not touching the tweeter, but it's close. Very close.
Here you have the back of the tweeter unit. Yes I yanked out one of the connector spades by accident. Anyway, it's a shielded unit solidly glued into the plastic base. I have no idea whether it's a custom-built driver, or some off-the-shelf unit with psb's branding on it. Considering the price of these speakers, it's probably the latter.
(Mid)Woofer
A 5 1/2 inch poly unit with a metallic coating. Quite an interesting unit because of how unusually deep it is. Also note the ogive-shaped dust cap. It's very rigid. I couldn't deform the dust cap by pinching the sides. The surround is rubber.
Here is the back of the woofer. Yes the motor is taller than the stamped basket; it's not just the angle of my photo. Note how this unit isn't visibly vented. Some woofer units have vent holes at the coil area of the cone; this is not the case here. The spider appears to be of good quality; the tinsel leads look like woven copper. Also note the paper-thin foam "gasket" that barely does anything to seal the woofer unit to the front baffle. Again, this is probably an off-the-shelf part with psb's marking on it.
Cabinet
Holy poly-fill, Batman! There are four sheets of poly-fill in this cabinet, each an inch thick when uncompressed.
Crossover
The crossover appears to be a second-order unit with two caps, an air core and an iron core, plus a resistor for level-matching. Also note the rear baffle. It is a piece of plastic that sounds as hollow as it looks. The front baffle is the same thing, which probably explains the large amount of poly-fill in this cabinet.
Conclusion
These things sound great when played at easy-listening levels. At rock-out levels the sound quality just collapses. Diffraction? Comb filtering? Cone breakup? I think cone breakup definitely plays a part because of how disturbingly flexible the woofer diaphragm is, despite the very rigid dust cap.
Now to dispose of all that poly-fill without spreading those yellow fibres everywhere...
The psb Alpha B1 are my first "decent" speakers, purchased at a retail price of $299 CAD/pr. Needless to say that I have long outgrown them in the ten years since, and I'm fed up with trying to offload them through my local classifieds, so here I am ripping them apart.
I am not a speaker reviewer by any means.
Overview
Yes I took this picture after having removed the screws. There was also a metal mesh grille on this speaker that couldn't be removed normally: I pried them off using a thin flathead screwdriver.
The first thing that struck me (and probably you too) is how close the tweeter and woofer are placed together. The second thing that struck me is how recessed they are into the front baffle. See that curved lip up top? Well it's the same thing at the bottom, and the grille is curved to conform to that. There are also raised lips on the straight sides. Diffraction central? You be the judge. All I know is the sound quality of these speakers fall the heck apart when I try to play them at rock-out levels.
Also I have no idea why there is an array of dimples up top where the tweeter is. Some manufacturers put dimples into their tweeter waveguides though is this clearly not the case here.
Tweeter
This is a one-inch unit. psb calls it "aluminium dome". Yeah, uh, it's not. It looks like a silk unit with a metallic coating. The surround looks to be part of the driver's weave.
The... triangular diffuser looks more like something designed to dampen/smother the treble. It's not touching the tweeter, but it's close. Very close.
Here you have the back of the tweeter unit. Yes I yanked out one of the connector spades by accident. Anyway, it's a shielded unit solidly glued into the plastic base. I have no idea whether it's a custom-built driver, or some off-the-shelf unit with psb's branding on it. Considering the price of these speakers, it's probably the latter.
(Mid)Woofer
A 5 1/2 inch poly unit with a metallic coating. Quite an interesting unit because of how unusually deep it is. Also note the ogive-shaped dust cap. It's very rigid. I couldn't deform the dust cap by pinching the sides. The surround is rubber.
Here is the back of the woofer. Yes the motor is taller than the stamped basket; it's not just the angle of my photo. Note how this unit isn't visibly vented. Some woofer units have vent holes at the coil area of the cone; this is not the case here. The spider appears to be of good quality; the tinsel leads look like woven copper. Also note the paper-thin foam "gasket" that barely does anything to seal the woofer unit to the front baffle. Again, this is probably an off-the-shelf part with psb's marking on it.
Cabinet
Holy poly-fill, Batman! There are four sheets of poly-fill in this cabinet, each an inch thick when uncompressed.
Crossover
The crossover appears to be a second-order unit with two caps, an air core and an iron core, plus a resistor for level-matching. Also note the rear baffle. It is a piece of plastic that sounds as hollow as it looks. The front baffle is the same thing, which probably explains the large amount of poly-fill in this cabinet.
Conclusion
These things sound great when played at easy-listening levels. At rock-out levels the sound quality just collapses. Diffraction? Comb filtering? Cone breakup? I think cone breakup definitely plays a part because of how disturbingly flexible the woofer diaphragm is, despite the very rigid dust cap.
Now to dispose of all that poly-fill without spreading those yellow fibres everywhere...
