I just internally rewired my KLH 5s, nice results

[Dowto1000]

Hi everyone,

This is my first post on this Forum. Between my good friend and myself, we have three pairs of KLH 5s, one pair of KLH Model 12's, and he, a number of Advent speakers. We are life-long audiophiles in our mid 60s.

Since I have my friend's two KLH 5s to use as a handy reference, and I like to modify things, I have started a restore and re-do my KLH 5s.

I did the usual thing to the exterior, a palm sander with 100 grit, 220 grit, 800 grit, and some oil to bring up the finish. Looks MUCH better, acceptable.

I replaced the crossover caps with bipolar electrolytics from Parts Express. Yes, I had film caps on hand, but I was hesitant to add them because they play louder and I did not want to upset the stock speaker's balance. So, the crossovers' cap re-do was conservative, close to stock with fresh bipolars, and I am pleased with it as a start point.

SPEAKER WIRING, INTERNAL :

If you look at the stock speaker wire, it looks rather low grade and thin. It seems obvious, much energy, and particularly peak instantaneous energy to the drivers is getting lost in that P.U.ny wiring. I decided to use readily available parts, and execute readily reversable changes to the KLH 5s, so others may duplicate my results, or eliminate them and get back to stock.

For wire, I used Kimber Kable TCSS. If you use a low AWG wire, say 12 AWG to the woofers, MOST large wire has a negative sound, it rolls off the highs and sounds "funny / odd" to me, sorta like a blanket was put over the speaker, a wool blanket.

So, after selecting the Kimber Kable wire brand, (which I have often used in the past and is readily available), I did the following:

1) I cut all wire lead lengths 28.62 inches long. ( long story )

2) I ran one set of TCSS to the tweeter.

3) I ran TWO sets of TCSS in parallel to the mids, including the span between the two drivers.

4) I ran THREE sets of TCSS in parallel to the woofer, as it takes the most power.

5) I eliminated all the clip-on terminals, and soldered the speaker wire directly to the drivers and crossovers.

6) I used Wonder Solder "Classic" ( from Michael Percy) and highly recommend it. Have good ventilation when using it, it is toxic, ...' has much more than lead in it :-) !!

By using what I consider to be an "appropriate" number of leads to each driver, proportional to the peak currents it may like to see, I have eliminated the "big wire / woolen blanket" sound, and the signature of the wire is consistent, top to bottom.

In addition to the speaker lead rewiring, I removed my crossovers entirely from inside each enclosure. I went to Lowes, got a 6 inch wide length of 1/4 inch Oak, and cut it into two 6 by 6 1/2 inch rectangles. I used 6 (of 7 in my later - "PC board" crossover) stock KLH screws that held in the crossover, to hold in the oak wood. Under the oak wood, ( between the oak wood and the speaker enclosure's body), I used 1/8th inch sheet of cork, to act as a gasket to seal the oak, so it is air tight.

I used the smallest drill bits possible, to make holes in the oak for the new Kimber Kable TCSS speaker leads to exit the enclosure, and reach to the crossover. I applied a silicon RTV-like seal to each hole through the oak, inside and outside the enclosure. I soldered the TCSS lead out wires directly to the crossovers.

Well, subjective listening results were lovely. Much lower in distortion, and the speaker overall sounds much better. Power from my amplifier ( a Harmon Kardon HK-730 ) got the drivers to strut their stuff in an unprecedented way.

I really am pleased with this first round of mods, so is my audio friend. He heard them late at night, and left me the following email message..... " speakers sounded fine tonite....crisp but sweet and clear...fast with power....".

Thats all for now.

Has anyone battery biased their KLH crossover caps ? Thats on my list.

Also, since I use the "normal" user-selectable speaker positions with a good front end / source, I have figured out how to simplify the crossover wiring and how to wire-out the switches in the crossover. That will be another thing to evaluate, as one of the step-by-step things I plan to do.

If the internal speaker wire isn't right, you can't tell much about anything else. Its the first mod to do I believe. The proceedure applies to all KLH Models I would guess !!

Comments, criticism and input always welcomed.

Jeff