Wednesday, April 15, 2015

Applying "audiophile" concepts to a pair of DIY speakers

When I was living with less means than today, I'd found a pair of Infinity bookshelf speakers with rotted woofer surrounds. I found a pair of Peerless Nomex 6.5" woofers at which fit the cut-out in the speaker cabinet. Being a fan of AMT and similar high frequency drivers, I found that the BG Neo 3 planar tweeter. Had to cut out an opening for them, however as they are significantly larger than the dome tweeters which came with them. Since my holes were not symmetric, I used modeling clay to seal off the inside. The cabinets are unported, are fully sealed.

This is well and good; I found some Infinity crossovers with "cups", or the fitting containing the speaker wire terminals, at a surplus store for only a few dollars. Hooked it up and it sounded fine, no distortion from a tweeter crossover too low in frequency, etc. Absolutely ludicrous to cut-and-paste a two-way crossover with drivers different than that for which it was designed, but the ears are the final master and mine said "fine".

The story does not end there...the crossover had ten cent capacitors, white sand-encased 5W resistors, cheap inductors...and I'd been reading "audiophile" sites about I unsoldered one crossover and measured the inductors and wrote up a schematic.

Over the years I've been spending a little at a time to upgrade the crossovers and I can easily tell you that there is real truth in what I've been seeing about "audiophile" technology. I've replaced the most obvious capacitor, the electrolytic one in front of the tweeter, with a good set of film capacitors, the resistors with inexpensive Mills 5W types (only a few dollars each) and one of the woofer caps with an Obbligato oil type cap. I have experienced a definite improvement in my listening. One way I've described it is that one early music CD, an Alia Vox collection, has a few pieces with vocals. Before the new resistors and caps, I used to skip a good half of the CD believing I didn't like particular songs. What was occurring is that the cheap components were resulting in a mess where the voices were too close in frequency, producing a blurry sludge. Irritating. Upon replacing the tweeter cap etc., I was suddenly interested in the entire CD...!!

Most recently I've replaced the small inductors in the tweeter circuits with $20.00 Mundorf coils. There is again a positive difference, detail revealed, depth improved, and more. But most importantly, I've taken the advice of humblehifi and bypassed the tweeter capacitor with a Vishay MKP1837 10nF (0.01uF) metalized film cap, each. Things have become even more open and detailed without anything becoming overwhelming, etc. It may be a tired metaphor but it is as if a somewhat dirty window were cleaned a bit more, revealing a bit more...

The best part? These caps cost $1.00 each. Note that some of the top audiophile caps can cost hundreds of dollars, each. You do need to have a good cap in the circuit for this bypass to really work but even a good one plus this should be a great combination. I've heard counter-melodies and details I'd never before heard in just the few CDs I've played since making this mod. I'm pulling out CDs to listen for fun, to know them better, which is the mark of any worth-while upgrade to a music system.

More: Yes, capacitors etc. take time to "burn in". I have noted a change in sonic character as this occurs as I modify these speakers. Expect it to a degree, as well.

Vishay Roederstein / ERO MKP1837 - 0,01uF / 100VDC / ± 1%


The Vishay MKP 1837 Review and Modification

Please note that excepting the Vishay bypass capacitor treatment, the differences may be described as "subtle", in that they're not huge, "everyone can hear it" differences. BUT. I'm definitely getting more out of my listening experiences as related to the Alia Vox CD. A difference compelling enough to not only keep but to pursue in other directions.