Bi-wiring

I'd kick off by saying that bi-wiring is a YMMV practice.

I know, some audiophiles have reported positive improvements from bi-wiring their loudspeakers, while many others have pooh-poohed the practice as they could discern no change or no improvement at all.

I have been wanting to try out bi-wiring between my Pass Labs XA160.5 monoblocks and the TAD-CR1 loudspeakers (incidentally, each  XA160.5 comes with 2 pairs of output binding posts, easily facilitating a bi-wiring arrangement).

The missing bit was another pair of compatible speaker cables to go with my existing JPS Superconductor 3.

I am in the school that cables don't (always) sound the same, so I was concerned that if the 2 runs of cables used in my bi-wiring exercise were of different make, then I could get a ying-yang sound. So, I was adamant from the outset not to mix-and-match speaker cables, and that the 2 pairs of cables must also be of the same length.

What with JPS no longer having a dealer in Malaysia, I had to wait for a pair of Superconductor 3 to turn up the used market. A pair did turn up fortuitously, and I happily became their new owner.

What were the reasons for my interest in bi-wiring?

I thought of these:

- increased contact surface for the connection between amp and speaker, as 2 pairs of connectors are used for each channel instead of 1 pair.

- increased cable cross-section area for the signal path, kinda like giving a wider highway for the signal to pass through.

- reduction in the number of "junctions" in the amp-speaker connection with the elimination of the jumper cables between the bass and the mid/high sections of the speakers. The signal sees a straighter path to pass through.
(With the use of a jumper, the signal path at the speaker side is Speaker cable -> binding post -> jumper -> binding post. Each "->" signifies a "break" in the connection.
Without the jumper, with bi-wiring, the signal path is simply speaker cable -> binding post.)

All these would reduce the impedance in the amp to speaker connection, thus would hopefully better preserve the signal integrity.

Of course, it could be argued whether my thinking is entirely scientific or that the effect is significant enough to be audible, but let's not go down that road for now. 😉

The proof is in the pudding as it is said - so I took off the speaker jumpers linking the bass terminals to the mid/high driver on the TAD-CR1, hooked up the second pair of JPS Superconductor 3 and listened.

From the get-go, I heard a few improvement areas that I liked, which were also somewhat in-line with my expectations:
- There was an impression of increased extension at both ends of the audio frequency
- There was a better grip and improved definition on the bass notes
- Clarity and transparency of the sound from top to bottom improved quite a bit
- A somewhat more expansive and more enveloping sound-stage
- The amount of details in the music improved, low level details could be heard more clearly. This was the most pronounced improvement among the lot.

But this trial did not come with zero downside. I could sense a "discontinuity" between the bass and the mid/high regions (the TAD-CR1 is 3-way. The lower binding posts feed the bass, and the upper ones feed the midrange and high). The character of the sound shifted a bit as the notes traversed the music scale. The sound was relatively more transparent and had better definition and excellent pace and attack as it went up the frequency scale, but as it plowed the depth, there was a tad of added warmth and the proceedings became a tad languid relative to the high, though in absolute sense the bass region had seen significant improvement from before.

So this was not a plug-and-forget kind of tweak. I had to solve this difference in tonal balance.

The Superconductor 3 was factory-fitted with WBT copper spades as standard, but I upgraded my original pair to WBT silver spades on my own. The second pair of Superconductor of course also came with the standard WBT copper spades, and there I suspected was where the culprit lie. The differences in tonal balance I heard were the same as my impression as I moved from copper to silver WBT spades.

So, I had to bite the bullet (i.e., spend money) and changed all the copper spades on the second pair of Superconductor 3 to WBT silver too. And behold, the tonal difference issue was solved.

Things didn't stop there. Thereafter, minor adjustments were still needed to better accommodate the improvements, for example the increase in perceived details would also make the sound a little more forward or slightly bright at certain places, the bass could be a little overbearing on some recordings too. Minor room treatment tuning allowed me to resolve these small issues in my case.

A few audiophile friends also tried out bi-wiring subsequently and shared positive outcomes with me, though a couple also reported tonal difference issue as they didn't have 2 runs of similar cable to try out.

So, bi-wiring is here to stay in my system. It is a winning practice from my point of view.

Things I learned - keep both pairs of cables absolutely the same, in make, in length and even down to the connectors; it is not a plug and forget thing, expect to work a little to resolve some issues that bi-wiring might throw up at the same time as it releases greater capabilities from your system 

I do keep an open mind that bi-wiring would not work in some systems or with some speakers though - so YMMV.

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P.S., I know, bi-amping is even better than bi-wiring. But I have no access to another pair of XA160.5 to experiment, unless some kind souls like to loan me a pair of power amp or a quartet of monoblocks to try out. 😉
And no, I have no desire to try mixing different amplifiers with my Pass Labs for bi-amping, at least not with the TAD-CR1, I don't want to mess with its outstanding top to bottom coherency.

P.S., Before I found my second pair of speaker cables for bi-wiring, I actually tried changing the factory fitted jumpers on the TAD-CR1 to after-market ones from reputable cable companies, costing from a few hundred to a couple of thousand Ringgits. I found none of them could match TAD's factory-fitted jumpers, let alone better them. So,  I had to move on.