The Sencore is a fine unit. I use Gold-line's equipment (TEF 20)because it offers tests that the Sencore doesn't match and interfaces well with the gold-lines EQ's. The TEF is really a superior system actually it is in a whole different league. But you will have to spend some time to learn to use it.

Gold-line also makes RTA's, the DSP 30 is nice but no great advantage over the Sencore. Each has its own advantages/ diadvantages but either can get the job done. The Sencore is more of an all in one unit where the DSP 30 uses other external devices for it's signal generators and speaker testers, etc.

There are other companies as well but I'm not familiar with them so I can't comment personally. One was just featured in Ultimate AV magazine by Ivie. It is based off a pocket PC device. Also, Terrasonde makes some units.

Bob