PSB Alpha System Build Quality

Upon inspection the first thing I noticed were the metal grills. When I received the speakers one of the grills was bent slightly and it never seated right in its frame. They were extremely hard to remove but I'm not sure it was really necessary to remove them. Typically I always like to remove the grills to eliminate any diffraction from the grill itself. In the case of the T1's the grills snapped into a frame, but removing the grills still leaves the frame which is part of the front baffle. All of the drivers were flush-mounted to eliminate diffraction from the driver itself but then there is the edge of the frame for the grill which causes diffraction. The front baffle was made up of two materials; the lower part of the front was MDF and the upper part where the drivers were mounted was molded plastic. Although it seemed rigid, the plastic was not uniform throughout. The rest of the cabinet was made from MDF. Giving it the old knuckle rap test, some parts sounded inert while others did not. Although this cabinet didn't seem to be the most solid design it didn't necessarily need to be. Since the speaker only plays down to 55 Hz they should be set up on your receiver as 舖 Small 舗 speakers and have bass management applied to them. At that setting you are most likely cutting them off at 80 Hz which somewhat reduces the burden for the manufacturer to more amply brace and reinforce the cabinet structure. Keep in mind that this is the PSB entry level speaker. I like to look at it as a bookshelf speaker with a built in stand. That also means that you'd better plan on having a subwoofer or two to go with these T1's.

Taking a look at the inside revealed some interesting things about the design. The woofers were magnetically shielded but the neodymium tweeter was not. I'm not sure if that matters or not but nowadays people are going to digital displays and CRTs will soon be a thing of the past. The 5.25 inch woofer itself was built on a stamped frame which is old technology. Almost all modern drivers are built on a cast aluminum frame for rigidity but many of the budget designs like this still use stamped frames as a cost savings measure. While in the DIY world a stamped frame may be highly frowned upon, it is understandable for budget-minded products like this. Behind the drivers was a bat of 3 ½ inch fiberglass. Speaker design practices say to leave a clear path from the woofer back pressure to the port. This practice wasn't followed since the port is in the rear behind the woofers. There was no absorption material on the side walls or top which would help keep the mid frequencies from reflecting and impinging on the back of the driver cones. The bottom part of the cabinet was completely stuffed with fiberglass with a layer of felt between the upper and lower part of the cabinet. I am not sure the purpose of the felt but it is not acoustically transparent (more like translucent). I think some of that felt should have been used on the side walls for absorption. There was a cross brace behind the tweeter and a shelf brace between the upper and lower parts of the cabinet.

I figured the crossover was somewhere on the bottom near the speaker cup. I didn't think it would be on the speaker cup itself but that's where it was, on the back. I expected something a little bit larger but I am used to seeing a lot more "meat and potatoes" I had to keep reminding myself that these are small budget speakers in a big box, so the design of all components - from box to drivers to the crossover system have to take this in mind in order to get the best bang for the buck possible.

The C1 center channel speaker has the same drivers as the T1 and is essentially the same speaker but in a smaller cabinet. Similarly the B1's are a two way version of the T1 speakers. Both the C1 and the B1 have multiple mounting options. There are a variety of threaded inserts for mounting brackets and two-way keyholes are also provided for hanging the speakers. To my surprise these speakers like the T1s are rear ported. If they are to be hung on the wall or even close to it the rear port gets blocked. I am not sure what the thought process was here but I see this as a design flaw. To circumvent this issue, I recommend stuffing the ports and applying bass management to these speakers when mounting them on or against the wall. The loss of low end extension by doing this wont be realized since you are crossing them over higher than their tuning frequency while at the same time achieving a more uniform sound by reducing boundary gain issues.