How To Properly Rebuild The
Klipsch RP-600M Bookshelf Speaker
So They Sound Superb!

The Klipsch RP-600M bookshelf speaker has been reviewed favorably by most reviewers and is an excellent value if you can purchase a new pair for close to $300. Then spend another $300 and a couple of days rebuilding this speaker so it sounds really good.

When I was in my 20s, I purchased my first Linn Sondek LP12 turntable based upon a local audio store telling me that the SOURCE IS MUCH MORE IMPORTANT than the speakers. They set up a listening room with the best source components and a really cheap bookshelf speaker. I listened to that system. Then they set up a cheap source component system with their most expensive floor model speakers. WoW!

What a difference and the best source component with inexpensive speakers won by a mile! Based on that demo, I purchased the LP12 turntable and began another leg in my audio journey. This wasn’t my first but that knowledge stuck with me throughout my adult adventures and I always came to the same conclusion no matter what the audio system was or its budget.

Spend your largest amount of money on purchasing your source components (your DAC, turntable if you use one, and especially your power amplifier since that choice affects your sound quality the most). If you can’t afford to purchase a similar quality pair of speakers, don’t worry. You can always take the cheap RP-600M Klipsch bookshelf speakers and modify them and end up with an audio speaker system for around $600 that will keep you mesmerized and willing to listen to your system while you save up for the next pair of expensive and better sounding speakers.

I recommend the RP-600M ONLY IF IT’S MODIFIED the way I recommend doing it. You need to take it completely apart and remove all speakers and components and then take out the cheap damping material and scrape the excessive amount of nasty glue from all of the interior surfaces of each speaker. Use a sharp chisel that is around 3/4″ to 1″ wide and this will make your job much easier.

Once you’ve cleaned the interior MDF walls well, then line the interior walls of the cabinets with GR Research NoRez damping sheets. These sheets cut easily on a small portable contractors saw. If you don’t have that, then use a good dry wall knife with sharp blades and suffer a bit. The end result is worth it.

When the speakers are cleaned and lined, then fully replace the crossover in each one with a totally new crossover network. Use the crossover network parts values that I’m sharing here. I use 1/4″ thick plexiglass crossover boards but you can use any wooden boards that are cut to the same dimensions. These board can easily be 1/4″ to 1/2″ thick and screwed to the bottoms of the speakers. Make sure to position the crossovers so that there is room for the front woofer to clear the front capacitor and also the new binding posts to clear the rear inductor. You’ll need to do this visually and then once positioned properly, you can screw the boards into the bottoms of the speakers. You’ll only need to do this once the crossovers are built and the wires are soldered to the crossovers and the speakers.

Replace the cheap binding posts with good WBT posts (their lowest cost version) and fill the other 2 original binding post holes with screws and nuts. Don’t biwire and only use one pair of posts. Also, there is no need to replace the Klipsch binding post plastic casing even though it isn’t laid out well for a pair of binding posts. Your sound quality won’t suffer and there is no need to increase your cost using a custom binding post plate.

I don’t have time right now to go through the entire process involved but you can use the photos that I’m including below to figure out the initial parts you need and to basically copy what I’ve done to end up with $600 speakers that will keep up with commercial speakers many times their cost. I also built a pair of MDF stands and used rolled on Dura Tex paint to finish them. The total cost for my MDF was around $20 and I used paint left over from another speaker build to finish them.

I did add a pair of .01 Dueland silver bypass caps to the tweeter caps (the 2.2uf ones) and a pair of Dueland .01 tinned copper bypass caps to the woofer caps (the 3.3uF ones). This extra cost is fully acceptable even though it now brings the total cost of these upgraded speakers to around $800. I highly recommend doing this. Your choice! The Clarity Caps are neutral sounding and these Dueland caps are responsible for the ultimate beauty of this speaker system. You’ll be hearing the beauty of the Dueland caps and not the Clarity caps if you do this. You would be amazed at what this pair of small bypass caps does to the ultimate sound quality. Remember, that it will take a good number of hours for these caps to open up so be patient. You will be rewarded in the end.