Hello All; One thing that I have noticed is that speakers that are mounted facing upward tend to have more problems then those mounted in the vertical position. The speaker for the radio in my Imperial is in perfect shape and is so because it is mounted in the front of the dash rather then on top. Even without the heat the horizontal mounted speakers tend to collect dust which often works its way in between the voice coil and the pole piece causing a grinding noise. If the dust doesn't work its way into the voice coil it still makes a rattling noise from the dust bouncing around in the cone. The only exception seems to be if the speaker has some sore of baffle on top of it to reflect the sound to the side. These baffles seem to prevent the dust from getting into the speaker as much since they are usually mounted inside of a cabinet that encloses the speaker. But since your car speaker only has an open grille on top it will encounter not only the dust problem but the U.V light braking down the cone. Back in the mid thirties it was quite popular to mount speakers in this fashion in house sets, needless to say this trend didn't last long. Not only did they have the dust problem, that I described, but they usually had the speaker mounted over the tubes which produced enough heat to broil the cone. Another factor that probably killed the idea was the fact that you couldn't put anything on top of the cabinet or put the radio on a bookshelf as the sound would be blocked, they didn't have those deflecting baffles in those days. The auto industry started mounting radio speakers in the horizontal fashion in the late fifties, I guess for styling purposes. In spite of the fact that they encounter the same speaker problems, as previously described, they still continue the practice. Obviously they have learned nothing after several decades of experience, if they did they would mount the speakers in the kick panels as a standard rule. Best Regards Arran Foster 1954 Imperial Newport Needing a Left Side Taillight Bezzel and Other trim parts. ----- Original Message ----- From: "Bob Schmitt" <bsbrbank@xxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Wednesday, January 23, 2002 5:56 AM Subject: Re: IML: An auto speaker tutorial > Mike - > > > > Actually, the two most important characteristics of a > > speaker (in terms of quantifiable measurements, at > > least) are dB/1 watt (sensitivity) and frequency > > spectrum. > > Nice tutorial. The non-quantifiable quality is "SOUND". Obviously, all > speakers don't sound the same, even if they have the same specs > (Consumer Reports notwithstanding). Listen to the speakers and try the > better brands. BTW, I think the/my orig. '66 mono speaker has a decent > sound. > > Bob > >