Rebuild Old Radio with up-to-date components

[LuisFF]

Hello everyone, i need some tips for my first build. I have an old (really old) radio that is not working anymore, so i want to reuse the exterior and replace the electronics with nowadays components.

This is the first time i am trying to build a sound system almost from scratch so be patient if i write something wrong and feel free to give your opinions and share links to tutorials. Also i hope this is the right sub-forum, otherwise let me know and i will move it.

I have read a lot about enclosure types, speakers and combinations, etc but i am still stuck, mainly because i would like to reach the best quality possible instead of just picking a pair of random speakers.

I want to build something that is focused on sound quality, not volume. As for the complexity of the build i would like to start simple, such as with Full Range units (although i would also like to have an alternative build with 2 way separate units, and consider that for a next build). I am trying to keep this project within an acceptable price, so lets say that i would like the speakers to stay bellow 100 eur.

The amplifier i have at the moment is this 2.1 2x50W + 100W Amplifier

Here are the measurements for the enclosure and a couple of pictures:

• Radio - 54 x 33 cm (the metal plate on the bottom will be removed to make space for the amplifier and power supply
  Photo 1
  Photo 2
• Mounting surface - 47 x 19 cm (the board will be replaced by a new one, so don't mind the existing hole and decorations)
  Photo 1

Here are some questions i would like your oppinion:

• Stereo or mono? Since my objective is not high volume and budget is important, do i gain that much by going for 2 channels instead of 1? I prefer to use those savings in better quality speakers instead.
• Closed or ported? I am aware of the advantages and disavantages, but in this case the size of the enclosure is unchangeable, so what is the best for this size?
• Passive Radiator or external Subwoofer? I want to have a good cover of the low frequencies, but i am not sure if i can do this all in the same enclosure. I don't mind having a separate subwoofer that can be connected to the radio to "extend" its capabilities.
• Single Full Range speakers or separate 2-Way? The idea is to have the best sound quality within the budget and the available mounting space.
• How to choose the right speakers? I know this is complex, but i am hoping for some tips on how to get started, with time i will go deeper into this.

Thanks for your help

 

[DF96]

Your requirements are mutually exclusive. You cannot have 'best quality possible' using an old radio cabinet. It will be far too flimsy and has an open back. The original system would probably have been around 3W maximum output.

For stereo you need two identical units spaced apart. You can't get stereo from one small cabinet with room for only one speaker. Stereo is not a way of getting twice the volume!

You need to rethink your aims for this project. Making a vaguely pleasant mono sound is one possibility, by using a full-range speaker.

 

[LuisFF]

Your requirements are mutually exclusive. You cannot have 'best quality possible' using an old radio cabinet. It will be far too flimsy and has an open back. The original system would probably have been around 3W maximum output.

Thats why i added the word possible. I know its not an ideal enclosure but the idea is to have an old radio look, with a much more powerful sound then the original. I can tell you the wood is quite thick, probably more then many "standart" enclosures, and of course i will add a back cover. As for the original output power it doesn't matter since i am replacing all the components. But the question still stands, fully closed or ported?

For stereo you need two identical units spaced apart. You can't get stereo from one small cabinet with room for only one speaker. Stereo is not a way of getting twice the volume!

Maybe i phrased this the wrong way, indeed i will not achieve stereo sound by putting two speakers so close to each other. But i do want to have the option to have a subwoofer, and for that i could either go with 2 separate 1-channel amplifiers, one for woofer/tweeter and one for subwoofer, or (to keep it simple) one 2.1 amplifier. But by choosing a 2.1 channel system, i can't simply ignore one of the channels and only connect one side, faking a 1.1 system.

 

[DF96]

Fully closed or ported depends on your aims and what speaker unit you choose. There will be people in the speaker areas of this forum who can advise you.