Recording Speed When I record something on a tape, I can listen back to it on the recorder no problem, but as soon as I play the tape in a different device, like a stereo, the tape only plays at a really slow speed. It seems to be recording at too fast of a speed.

The tascam 414 is a 4 track recording studio which uses standard cassette tapes- meaning they only play in one direction, because the tape is full. The 414 records at double speed so that recording fidelity is increased. When you have made a recording you want to mix you then dub your recording though the outputs into another standard tape recorder or whatever you have available, be it a cd recorder or your PC. So, when you listened to your recording on a standard tape player, you were not only hearing it at half speed but you were only listening to 2 of the 4 tracks. The other tracks would only be heard if you flipped the tape over, and they would be heard running backward. I would have though the 414 had a swich to allow it to also record at standard speed to but I guest it does not.

I've just bought a 414 and reading through manual I find that it records and plays at twice normal cassette speed. This is normal and how it should work. A c90 length tape last about 20 min and plays one side only. You can play it out to separate speakers through the headphone jack. I dont know about playing through line out etc. The manual also mentions playing the result to a 2 track recorder whatever that means. Still learning

I have a 238 and is designed to record at double speed for a cleaner recording tracks. It will not player a regular cassette tape. You must mix your tracks down on a audio mixer then re - record them to a regular cassette player or CD recorder.

Are you referring to a compact cassette?
It would seem that the tape recorder you are recording on has the problem. Either there is a high speed dubbing option (if it is a dual deck cassette), or most likely, the pinch roller is not working.
Pickup reels on tape recorders turn faster than the tape speed. The pinch roller (the small shiny pin and rubber roller that presses against it) govern the speed of the tape (causing the pickup reel to slip via a spring loaded clutch). If the pinch roller does not engage (the tape being sqeezed between the pin and rubber roller), the tape moves quickly across the head, causing tapes from other machines to play too fast, or recordings from this machine to play slowly on other machines.
Google 'cassette pinch roller' and choose the images tab to get an idea of what to look for.