I have searched for a new radio receiver and/or boombox, but none have been perfectly satisfactory for me (although the 3-speaker TDK "Life on Record" unit did initially seem appealing), so I have decided that I shall build my own. I have never before undertaken a task of this magnitude, so I shall definitely need to carefully plan every stage of the project, and I shall also be seeking advice from other users, here.
I plan to use a car audio system and place it into a case that I shall construct myself. For the case, I plan to use the slotted steel bars that are often used for stop signs as its internal frame, with the aluminum plate with diamond pattern that is often used for toolboxes as its external casing, held in place by nuts and bolts and welded together at the edges. I shall also likely put rubber feet on its bottom, for stability, and have some form of handle to carry it around.
That part of the project shall be relatively easy in comparison to selecting the electronic parts that I shall use. I shall use the receiver/console from a car's audio system as the main unit of my device, and, as most of those receivers have four audio channels, I shall install four speakers in the device: two in its front and two in the rear, with a connector to attach a subwoofer unit to its separately. I shall also need an amplifier, preferably a 5-channel amplifier, so that the receiver can power the subwoofer without needing a separate amplifier for it. However, there are so many different brands of these devices that I am uncertain as to which I should use for my project, and I also am uncertain about what I should use to power this device.
For the receiver, I seek a device that can receive AM and FM transmissions, can play CD's, and (most importantly) allows manual auxiliary input through a standard 3.5 mm audio connector, so that I may use my .mp3 player with it. For speakers, I shall likely seek those with higher wattage, for better audio quality (I know that higher wattage is not automatically an indicator of better quality, but having higher wattage certainly does not make the sound quality any worse). And most essential of all, I shall need a battery to power everything. I was planning to use a sealed lead-acid 12-volt battery, which can be found at many major hardware stores, but I hope that such a battery shall be sufficient, as a car's battery must power far more than only its audio system, while the battery in this device shall be powering only the audio system.
Also, I am hoping to have a manner of charging the battery in the device, without needing to remove the battery from the device. I am imagining using some form of power converter to convert 120 volts from an average outlet (in the United States) to 12 volts, to recharge the battery, preferably while the device is in use, much like how a laptop computer can be charged while it is in use. I have found 12-to-120-volt converters, for charging household devices when driving a car, but I have not yet found a 120-to-12-volt converter, which is what I seek.
I realize that I have said much in a single post, but I am enthusiastic about this idea, and wished to provide as much information about it as I could. I actually cannot pursue this task until I can afford the price of all the parts that I shall require, but I wished to discuss it and obtain idea now, so that I shall have a clear direction and plan for when I am ready to pursue it. Thank you very much, and I await your responses.