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Alpha-core advise?

I recently tried some Alpha-core MI 2 speaker cable and was quite impressed. When I made inquiries at Alpha-core, two different engineers gave me conflicting advise. Perhaps some one here can straighten me out. My curent system uses a Threshold S/500 series II driving Thiel 3.5's. The Threshold according to Jon Soderberg who used to work for Threshold is capable of doubling down. The Threshold is rated as 250 Watts per channel. The Thiels are rated as 4 Ohms nominal and 4 Ohms minimum. Independent tests show this to be rather accurate (an amazingly flat load) with one peak at about 33 Hz to about 8 Ohms. Ergo the amp may be pushing up to 500 Watts per channel. It was originally suggested by Alpha-core that I use a pair of MI 2's for my requested 8' run. They latter suggested that I run two pairs (not a traditional bi-wire situation). Unfortunately the speakers binding posts couldn't accept more than one set of the attached silver spades. When I called back, a different engineer suggested MI 3's. I'm a bit confused by the "characteristic impedance" issue. If one were to double up runs of these speaker cables, would the "characteristic impedance" half?, remain the same?, double? or something else? One advantage to this speaker cable line is that they can be made in such a way that they could have integral "spades" rather than added on ones. The advantage of the MI 3's over the MI 2's, due to greater width would be increased surface area if they were terminated in this fashion. The advantage of using double runs of MI 2's would be decreased cost and perhaps (and this depends on the answer to the previous question) better impedance matching. The Alpha-core web site suggests that this design needs little break in. Would these cables benefit from the use of a cable cooker? BTW, I am now considering using 3 meter to 10' runs. What's a boy to do?
unsound
clio09
3,345 posts
 
My MI-2 Veracity cables broke in just nicely on their own over a weekend. No cable cooking required. I Have had them over a year now and love them.

As to your other dilemma I plead ignorance but am curious as to the outcome.
mapleleafs3
190 posts
 
very nice cables
oldears
385 posts
 
I have no doubt that the Threshold amp can deliver 500W, but that does not mean the speakers are demading all of that to require more than the MI2 cables can deliver. I personally think your cables should be sufficient and you state that you like the sound. The techs at AlphaCorps are not in conflict by saying that if you do not want to use doubled MI2s then you can use the larger MI3. And yes the impedance halves in parallel. You may benefit by looking up an old post from Sean about a Zoebel filter at your speaker inputs when using Alpha corps cables. I am very happy with the MI1 cables and this filter on a lower powered system than yours.
clio09
3,345 posts
 
When I purchase my MI-2s they came with the Zoebel network already integrated into the design. No extra work on my part. It doesn't hurt to have it on their even if you don't need it from what I was told by Alpha Core.
unsound OP
7,311 posts
 
Thank you for all the replies. I did use supplied external Zoebels when I tried these cables. Oldears, the techs (I was told they were engineers) actually did conflict. The first one said by using 2 pairs of MI 2's I would be doubling the "characteristic impedance" of 2.5 Ohms to 5 Ohms and there by creating a closer match to the speaker load. He also said that 4 lengths on the MI 1's would create a perfect 4 Ohm load, but, the binding posts wouldn't accomodate that. The second engineer said the opposite and that doubling up the lengths would halve the "characteristic impedance". As for the power output of the amplifier, let me say that it is used in a fairly large room (14' ceiling peak) and that the speakers use an active equalizer that boosts the signal below 70 Hz by up to 12 dB's. I would think that would put quite a demand on the amp. Alpha-core seems to have a funny pricing system, 2 lengths of MI 2's cost less than 1 length of MI 3's, yet they claim that the MI 3's have the perfomance of 2 MI 2's. Alpha-core claims that matching the impedance load is what makes their product special. To be fair, they also claim that absolute matching is unnecessary. From what I am led to believe equivilent runs of MI 2's would offer a closer impedance match at a lower price, the MI 3's would offer a less ideal impedance match, better/ bass control and more surface contact with "integral spades" at a greater cost. Any thoughts?
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