QuestionI have motorhome, based on '89 Ford E-350 chassis, Type C motorhome w/ full Ford van cab, hood & doors intact.
There is a big center access panel on top of dash for assisting w/ stereo install. Is there a speaker or speaker-pair of quality fidelity that will fit into this hole w/ panel removed?
I would like to install flush-mount stereo speaker(s) in this place. The advantage that I am seeking is to fill the middle void of the sounds created by right/left sterep speakers that are flush-mounted mounted into the lower padded door trim panels.
I think this would have to be a double speaker (left/right in one speaker) for this to sound correct. Also, it would help keep the volume level lower, since we play it kinda loud with the speakers 4-feet below our ear on one side and 7-feet from our other ear. Balancing the existing stereo speakers never suits both the driver and passenger simultaneously, since neither of us is seated between the speakers. Installing a center speaker should help, right?
AnswerI can help with center channel, but I must tell you that most of your woes are from the placement of the stock speakers and their lack of proper high range frequencies.
Use a pair of 4" full range speakers {if they will fit}.
*IF your head unit has 4 way powered outputs you could use the rear channels for the center, otherwise it may fry your head units' internal amps (if you run the fronts and the 2 center channels at the same time off its two channels)!
There are two ways to wire a center channel: the "bridged stereo" method and the "summed mono" method.
The bridged-stereo approach is the simpler of the two, since it doesn't require an extra amplifier.
You create the center channel simply by tying a third speaker into your existing left and right front speakers; and for all practical purposes, it will be mono, since it is the sum of the left and right channels.
The procedure is as follows:
Wire your two center channel speakers together in series. See note below.
*You can wire the two (4 ohm) speakers in series to help offest the low impedance but the total impedance will always be lower than the lowest speaker that is attached. This should give you about an 8 Ohm load for the center array as (opposed to 2 Ohms when in parallel). As to speakers, Series = "in the positive, out the negative and on to the next speaker".
Splice the positive lead of the center speaker array into the positive wire running to the front-left speaker and the arrays' negative lead into the negative wire running to the front-right speaker.
This connection is passive, since it's made after the amplifier.
NOTE:
You can add a high pass filter (6 Db/oct) at about 350hz by placing it in the positive lead wire to the centers, this will reduce unwanted low freqs and distortion.
If the head unit has 4 channel power, you can easily adjust the center volume with the fader.
If you choose to try and do this with a 2 channel head unit:
To control the volume of the center speaker, you install an L-pad (about $10 at Radio Shack) in line with the center speaker. This device is a high-power volume control that allows you to vary the power delivered to the speakers without changing the impedance "seen" by the amplifier.
Be sure your amp (internal OR external) CAN drive low impedance loads as this procedure will reduce the load on it causing high current operation which may indeed overheat and kill it!
I hope this helps gets you an idea of what you are into.
JM
