The fan exhausts leak some light, which is commonly found in lower cost DLP projectors. This can be a bit annoying if you’re lying down on the couch and you happen to catch the right angle for the light leak to go directly into your eye. I fixed this issue by moving the projector forward slightly, thanks to the modest amount of placement flexibility the zoom lens provides. The fans are on the sides of the projector, and slightly on the back on the left side, as well as a fan on the front.
On the top of the projector, towards the back lives the control panel. It’s a typical control panel and is discussed below. At the back of the projector we have all of the inputs and connectors, including some extras that make this a “crossover projector” that would be acceptable to use in classrooms or small to mid-sized conference rooms.
The two 10 watt speakers are located on the sides - in the back on the right side, mid-front on the left. These actually produce impressive sound, and we used them often. Though there is a definite difference in using external speakers versus the onboard, I would say these speakers produce some great sound for being built-in.
Underneath, there are two feet - but only one is adjustable. Again, this might be useful if you need to raise the right side of the projector (if you’re facing the lens), but not if you need to raise the left. I still wonder why Acer wouldn’t have spent the extra few cents it would have taken to make the left foot adjustable but hey, I’m not a projector manufacturer. Also on the H7550St’s underbelly are screw thread holes to attach a ceiling mount, which, naturally, is not included as many purchasers of a projector in this price range do not plan to mount the projector – so why “pay” for a ceiling mount.
H7550ST Inputs and Connectors
Time for a quick run-through of the input panel, starting at the top left side.

The Acer H7550ST includes VGA In and VGA Out ports, making it a crossover projector that can be used not only for home entertainment, but in business and education settings as well.
First, you’ll find an RS232 serial port for “old school” command and control - useful if you’ve got Crestron system or something similar. To its right is a pair of HDMI ports - HDMI 2 with MHL support (streaming sticks, interfacing to mobile devices, etc.), and HDMI 1. Directly under those ports is the DC SV. Next is a mini-USB port. Over to its right is the rear RF Emitter for the included remote control, then the S-Video and Composite Video ports.
Then comes the VGA In and VGA Out ports, having a VGA out is one feature that defines this projector as a crossover between business/education and home entertainment and possibly useful in a classroom or conference room. A VGA out is rarely used in a home environment! Next to those are three color-coded Component Video inputs (red, blue, and green), and a standard audio in/audio out for external speakers.
That’s it for the back of the Acer H7550ST, except for the power receptacle and a list of the projector’s best features printed along the bottom. Those graphics are HDMI 3D, 2D convert to 3D, MHL, dts sound, DLP 3D ready, full HD at 1080p, that it has DLP technology by Texas Instruments and is nVIDIA 3DTV PLAY ready.