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Terminal Blocks for Speaker Wire "Splitting"?

Background: I have a "mid-fi" stereo system in a 25x15 ft relatively well damped living room as follows: Yamaha R-S700 receiver, four Paradigm Atom V3 small bookshelf speakers in the corners (using A and B outputs) and an SVS PB-1000 powered subwoofer. The Yamaha has been known to blow a couple of Atoms when mishandled. Because of that and for nostalgic reasons I will be replacing it with a much lower powered vintage NAD 3020, which only has one set of speaker outputs and of course no subwoofer output.
The PB-1000 can be driven by L+R speaker level signals which it uses as low level inputs with high impedance. So, I need to split the speaker outputs into 3 sets (front, rear and sub). The NAD terminal posts are quite fragile and I do not want to jam more than one wire into each. I am using 12 and 14 AWG speaker cables.I am keen on decent sound but accept the limitations of the above equipment (have a much better system elsewhere).
So, to my question: Is there any objection to distribute the speaker signals through a pair of dual row 15A or 25A terminal blocks (L & R) and jumpers such as here:
https://www.amazon.com/dp/B07CLY5N9T/?coliid=IZTS4LPO2PS4X&colid=16XMVSQMO7S0V&psc=1&ref......
or even 45A ones such as here:
https://www.amazon.com/dp/B07DM83GZ5/?coliid=I1P22GXS9SOQ9Z&colid=16XMVSQMO7S0V&psc=1&re...
I would use 8 mm spades such as these:
https://www.amazon.com/dp/B009KSNVHM/?coliid=IB0RJN70IPBX2&colid=16XMVSQMO7S0V&psc=1&ref...
Would sound quality be negatively affected due to this signal distribution hardware or any other concerns?
Thanks!
yoramguy1
6 responses Add your response
yoramguy1 OP
68 posts
 
@spatialking , many belated thanks for this excellent guidance which I have actually applied in my solution, and shame on me and apologies for failing to acknowledge and thank you until now.
I ended up using four 5/16" fiberglass bolts, one bolt per line (L+, L-, R+, R-) anchored on a flat PVC bar, and at each bolt a nylon bushing at bottom and a fiberglass nut on top clamping a stack of four spades (amp output and 3 speaker feeds) for that line. Used 1 mm thick copper washers between the spades to ensure contact area. 
I believe this approach minimizes inductance (as well as capacitance).The result sounds very good to my ears. Thanks again!!
spatialking's avatar
spatialking
610 posts
 
Well, capacitance is a proportional to the area of the plates, in your case the bolt and washers, times a capacitance factor, which in your case is air, and inversely proportional to the distance between the plates.  So, if you want low capacitance, separate the bolts!    

Do note that inductance and capacitance is like a seesaw at the park.   If you minimize one you increase the other.   However, no worries, you won't have enough of either to make much difference.   In very general terms, for speakers, you do need to minimize inductance since the impedance of the loudspeaker is so low, inductance has a more significant effect than capacitance.
yoramguy1 OP
68 posts
 
@spatialking , thank you very much for this!!  Will pursue further. Another option I'm considering is building my own little "junction box" with all spades of each of the four signals (L+, L-, R+, R-) stacked together with copper washers between them on a 8mm nylon 6/6 or fiberglass bolt (anchored in a wood base) and clamped with nylon or fiberglass nuts.  This should minimize inductance but not sure whether it would reduce the capacitance over the industrial 45A box. 
I know all this sounds weird if not crazy but looks like the best solution to me... 
Critique (including of my own sanity) is welcome.
spatialking's avatar
spatialking
610 posts
 
You won't have an inductance problem but perhaps a capacitance one.  The jumpers are usually flat metal, such as nickel plated copper, that is wide and short.   It has very little inductance and very little resistance.   If you torque it properly, I don't see you having a sound quality problem.   I don't know what to tell you about unavailable jumpers - all the terminal blocks I have used have had jumpers as optional items.    Check with the manufacturer's website to be sure or talk to one of their sales folks.
yoramguy1 OP
68 posts
 
spatialking, thanks a lot for your feedback and advice. Yes, the 45A terminal blocks accommodate well the 8 mm post spades I intend to use, the smaller 15A and 25A ones don’t. Only problem with the 45A ones is I can’t find jumpers to distribute the signals to the other poles, like the red and black ones that come with the smaller blocks. Is the sound quality you experience good enough for "mid-" or "near-hifi"? My concern is more with capacitance and inductance effects on the impedance than simple resistance - any insights into this? Thanks again!-Yoram
spatialking's avatar
spatialking
610 posts
 
We use those larger terminals here at work and pump 5 to 8KW though them 24/7/365.  The smaller terminals you listed will be fine for speakers and the nice thing about these terminal blocks is you can torque the screws down.   That is a biggie for a low loss connection.   Just don't over torque them as the impedance gets larger, not smaller, when you over torque.  Do make sure those fork terminals will fit in the space provided, if not, you will need a larger terminal block. They are wider than they look!
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