Bi Wiring Speakers from Luxman L-509X


I'm looking at updating speaker cables and I'm convinced that biwiring with two separate sets will be the best approach over a single set of speaker cables with matching jumpers.  

My 509 has two sets of speaker outputs and I can select for the amplifier to drive both outputs.  So my plan is to run one set of outputs/speaker cables to the woofers and the other outputs/speaker cables to the tweeters.  

My question is will this create any compromises in the performance in any way?  I don't want to end up with improving one aspect at the detriment to another.  

Am I just overthinking it?
Ag insider logo xs@2xpinball101
So highs @ 8 ohms
lows @ 8 ohms

- to -, and + to + = 4 ohms

bi wired = the same resistance @ 4 ohms, the difference is the size of the conductor doubled (if you used the same size cable).

It might sound different if two different types of conductors were used. EX: OCC copper and PTFE in one set of cables  and OCC copper/silver clad and PTFE in the other set.. There is wiggle room for a sonic change by tinkering with cable compositions.. Terminal end type (copper, silver ect.) bare wire...

Regards
The amplifier sees the same speaker load either way. This should work just fine.
The amplifier sees the same speaker load either way.
@erik_squires +1 

So highs @ 8 ohms
lows @ 8 ohms
- to -, and + to + = 4 ohms
No!!!
The high pass crossover has high impedance at low frequencies and the low pass crossover has high impedance at high frequencies.
So " - to -, and + to +" basically still = 8 ohms.


"...I’m looking at updating speaker cables and I’m convinced that biwiring with two separate sets will be the best approach over a single set of speaker cables..."

I’m convinced that just like loudspeakers that two great ones (loudspeakers or cables) sound better than 4 average ones for the same money.

Also what cables and why is the more important question. 
The only downside is the cost of the extra speaker wires. The upside is highly debated, but experimenting is always fun. 
The low and high pass filters means the multiple drivers are not not seen in parallel by the amplifier. They are seen as separate entities.

For a better view to understand this, please see my post here:

https://speakermakersjourney.blogspot.com/2016/12/crossover-basics-impedance.html

My original statement, that using the A+B outputs to bi-wire a speaker is equivalent to using just A or B stands. The amplifier won’t know the difference and hopefully you’ll see the explanation in the post.

Using simple, DC analysis for equivalent resistances is not appropriate in this case.  It would work (with a lot of slop) with parallel drivers of the same type in the same section, like having 2 woofers for instance. 
The high pass crossover has high impedance at low frequencies and the low pass crossover has high impedance at high frequencies.
So " - to -, and + to +" basically still = 8 ohms.

<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>
imhififan, Erik is correct you are NOT

Measure a static load at the speaker terminal, not the driver. The amp sees that. The crossover may well have all kind of thing to add resistance to circuit, you still add the combine resistance in THAT circuit..

If you have two separate circuits ( lows and mid/high), no matter in a series or parallel crossover design, the law of 1/2 the total or the combined total still stands.

(If the lows are wired at 8 ohms and the mid/highs are wired at 8 ohms)

No, it's 4 ohms just like I said in parallel.  In series it's 16 ohms. (16 won't work, it is an example) The crossover can't work in series because of the way the signal would be passed from low to mid/high or vice versa. The load would still be 16 ohm load, the speaker wouldn't work correctly..

- to -, + to + (parallel) = 1/2 the combined total

- to + to - to + (series) = add the two together

Split the load between two different amps the amps sees 8 ohms ea.

If the highs are @ 8 ohm and the lows are at 8 ohm.

At least the 2-220 crossovers that I've repaired or built.. Maybe you got a different DMM LOL, people still amaze me..

Regards
you have convinced yourself; am I overthinking it? stand out to me.

https://www.audioadvice.com/videos-reviews/speaker-bi-wiring-bi-amping-explained/

what speakers?

note: these units, 2 pairs of speakers is not for bi-wiring, rather different spaces. the amp's power for each pair must be effected, there may be microseconds of timing delay, ...?

note: your Luxman unit specifically: the speaker's impedance restriction 8-16 ohm load if two pairs; 4-16 ohms if only one pair shown on the back of the amp. that indicates it cannot safely (within warranty) provide full power when both pairs driven. 
Lots of great input which I expected.

To answer one comment above, the primary reason for this question at all is cost. Two full pairs of cables is more expensive than one. At this expense I don’t want to get down the road and find it was not a good fit.

The plan is to get two sets with locking banana connectors. If I need to run them off of one set of speaker outputs on the amp then I would have to consider one set with bananas and one set with spades to allow both sets to connect to the same binding posts.

The speakers are rated at 4ohms. This presumes the woofer runs at 8 ohms and the mid/tweets run at 8 ohms to provide a combined 4 ohm load. Is this correct math?

So if the four 8 ohm driver circuits are connected to the two pairs of speaker outputs am I within the 8-16ohm limits when all four speaker terminals are connected?This, and Elliot’s comment above, is what I’m trying to sort out.

I believe I’m OK. Is this right?


this amp, existing 4 ohm nominal speakers, you are best with using one set of speaker outputs. single cable, or as you say, two pairs of cables that can fit together on the same terminals.

two pairs of speakers: neither can be below 8 ohm 'nominal'. little dips, ok, lot's of near 4 ohm, no.
OP your math is correct..

IF you have dual binding post at the speaker, bi wiring is a second pair of cables from the same common output post on your power amp..

If you have a single set of binding post at the speaker, your doubling the run, but not bi wiring. Does it make a difference, ONLY if the single  run cannot carry the load correctly.. Double the run or go to a larger size construct..

I've ran two different types of cables to the same binding post. Silver ribbon and OCC copper weave.. Nice combo.. Different story..:-)

Regards
The low and high pass filters means the multiple drivers are not not seen in parallel by the amplifier. They are seen as separate entities.

For a better view to understand this, please see my post here:

https://speakermakersjourney.blogspot.com/2016/12/crossover-basics-impedance.html

My original statement, that using the A+B outputs to bi-wire a speaker is equivalent to using just A or B stands. The amplifier won’t know the difference and hopefully you’ll see the explanation in the post.

Using simple, DC analysis for equivalent resistances is not appropriate in this case. It would work (with a lot of slop) with parallel drivers of the same type in the same section, like having 2 woofers for instance.
@Erik_squires  +1

I hope oldhvymec had read the link @Erik_squires provides for better understanding how a parallel crossover works.
I understand what Erik is talking about, that is impedance curves at the driver, it has nothing to do with load to the amplifier. The article is talking about how to CORRECT with a crossover design.

Proper XO point and knowing the driver by doing your own measurement with software/hardware.

https://www.parts-express.com/OmniMic-V2-and-DATS-V3-Dayton-Audio-Speaker-Measurement-Bundle-390-809.

I use this one and a few freebies, along with an active XO to actually test my XO, STUFF.

The static load doesn’t change (within a limit) of the frequency they respond to.. Ex: @ 8 ohms

Think of it like this. You have 6 drivers in a line vertical, you remove one, and put a resistor that matches the static reading of the driver in its place.

Will the resistance change at the speaker binding post? NO the curve will though, but the amp won’t know it.. it just sees a requirement and meets it.. As that driver is used throughout it’s notched out range phase angles can SWAP but the resistance remain the same..

Acoustic vs electrical, it's not the same thing. People mix them up.. I'm talkin before it leaves the box not after, there is a difference..

There is a lower limit there is an upper limit, but the actual resistance stays within that notch. IF the XO and drivers are wired and crossed correctly and care is taken to keep the load close to the static load, you’ve built a good crossover..

I’ve seen and fixed plenty that DIP to less than one ohm..

Kappa 8 or 9.0. Pure amp killers.. Not when I’m done.. 10 degree drop in amp temperature, too.

Regards
I was a big fan and totally convinced that using two separate runs of cables worked better than one set with a pair of jumpers. 

Boy, was I wrong.

With a money back guarantee, I tried a speaker cable I was always coveting with their matching jumpers and it was game over, for me.
The fact that they only cost me just over half their retail was icing on the cake. They were show demos. It pays to keep an eye out for them.

All the best,
Nonoise
I understand what Erik is talking about, that is impedance curves at the driver, it has nothing to do with load to the amplifier. The article is talking about how to CORRECT with a crossover design.

I’m afraid you’ve misunderstood then. Nothing in that article presents the impedance of any driver or measurement at the driver.

The first chart is an impedance curve of an actual speaker as would be seen by an amplifier while the next two impedance charts are the impedance, as seen by the amplifier if they were separated. It was my goal that these 3 curves (all from an amplifier’s view) would help explain why the tweeter and woofer are not really seen in parallel by the amp. I will endeavor to make that more clear.

In the last two impedance curves I use an ideal 8 Ohm resistive speaker load so the reader can see the part that is a driver vs. the part that would be contributed by the filter (high or low pass).
If you really want to notice a difference, spend less money on cables and put that money towards another amp …. And Bi-amp the speakers. I run a solid-state amp for the low end and a tube amp for the mid and highs. You get the best of both worlds!
The only reason you would bi amp is if you are using a dsp… IMHO
Wireworld  Eclipse 8, with several model choices uses only       OCC  Copper ,and best dielectric out there 
or other high quality options ,it is a very substantial  awg9 and can be bought with naturally biwire  and uses only silver plated ,or gold plater copper connectors ,not cheap gold brass like many ,and the spades,bananas 
screw on and can be replaced any times , very good balanced cables all the way up to the-top Platinum cable.
Why not just buy bi&- wire speaker cable if you're going to use wire use OCC single Crystal, Acoustic Zen and harmonic technology make a very good internal bi-wire cable.
Then answer me this what happen if the two frequencies are hit at the same time, What does the amplifier see then? It seems the sim is showing the the two different frequencies but not at the same time.

I'm sure there are a lot of fancy terms, I've left out, leaving out or just don't know, but a speaker crossover? I suppose they are complicated, but they sure don't have to be, by design or by explanation.

I'm seeing what happens in the sims I'm just not understanding in the music world how this equates.  Aren't different instruments being played at the same time? 

I also see super high ohms in certain regions, Wouldn't the amp see just that and be down XX db without a notch to bring the impedance down and volume UP. These are about as simple as can be to me, but it sure is being made complicated. I understand the port (s?) or two XO points, I use passive radiators, to change the Q. By design a lot of the XO in the sim is really limited.

But that simple XO in a real speaker isn't gonna look like that is it?

I don't run simulators, I don't build XO from scratch. I use a Quasi second order filter for everything above 300hz.

In my XO building I use the same basic drivers and have for 35 years.

Erik while your simulating, I'm replicating. I use to turn out a mid/high pass in 30 minutes.. Before the night was out I'd usually have 2 or 3 filters built and make my choice after a couple of swaps and listening sessions.. Add a LPad or two or three.

It's been 10 + year sense that time.. Maybe simulators are better, I don't know.. By the time I fiddled with the software, 3 days have passed.. I could have made 10 XO by then..  A DCX 2496 is just to easy to actually run the crossover I like and build from there. With over 100 different types, I still stick with ONE certain type. Software/hardware sets.. I find it a pain in the A$$ LOL

I enjoyed the read, but my notes are scribbled in a binder 50 years old now.. AND in left handed code..:-) I'm pretty analog lets say.. Only so much band width to play with.. :-)

Think Forest Gump... a good solid 80 IQ, I'm thick but my hand were quick..
Then answer me this what happen if the two frequencies are hit at the same time, What does the amplifier see then? It seems the sim is showing the the two different frequencies but not at the same time.

Lets assume an ideal 8 ohm tweeter and mid-woofer, with a perfect infinite slope crossover at 2 kHz. So perfect that at 1,999.99999999 Hz 100% goes to the mid-woofer and at exactly 2kHz it all goes to the tweeter. You would have an amplifier load that is exactly like a single, ideal 8 ohm driver without a crossover.

We know that current = V/R, but how would we ever calculate the current for complex music?

Imagine a test tones with two notes, 500 Hz and 4 kHz. 8Vrms each, with the peak voltage 2x the peak of either by itself.

In this case we have 2 A, because you take each section and add them.

8 Vrms @4kHz / 8 Ohms = 1Arms tweeter
8 Vrms @500 Hz / 8 Ohms = 1Arms mid woofer

Now imagine we use the same test tone and add a true woofer below 200 Hz, converting into a 3-way:

8V / 8 Ohms = 1A tweeter
8V / 8 Ohms = 1A mid
0V / 8 Ohms = 0A woofer

We added a 3rd driver, but the current did not rise. Calculating a total R of of 8/3 will not work here.

Let’s this time use a new test tone at 200 Hz but nothing else.

0V / 8 Ohms = 0A tweeter
0V / 8 Ohms = 0A mid
8V @200 Hz / 8 Ohms = 1A woofer

Again, the current is entirely dependent on the section it went to. In all of these cases, the answer is that the current and power is identical to a single driver because of the magic brick wall filter sections used.  Real filters are not ideal, but not too far off these examples we can't use them, and where the impedance curve drops to the impedance of the single driver you can see it is working very much like these examples.

Of course, multi way speakers and music is complicated and ideally resistive drivers almost never exist, and never match other driver types. :D You can’t really do this with music without a digital sampling mechanism, but i hope you can see that no, the drivers don’t add up the same way in an AC circuit with filters.

In the post I sent you I use a VERY typicical type of speaker build and crossover design, one you’ll find 100s of examples of in Stereophile. That peak between the mid and tweeter is the combination of the low and high pass filters. Split them apart, they go to infinity. Put them back together, either with jumpers at the speaker or bi wiring to the amp, and they meet in the middle at an amount a lot less than invinity, but a lot more than either driver.
That’s how marantz recommends to connect when bi wiring....A for low frequency driver, B for high frequency driver....or vice versa.....there is no detriment...on my sugden, it only has one set of speaker outputs. I use both spades and bananas on the amp end to connect two equivalent pairs of Audioquest type 4 cables, 4 meters in length. A Stereophile recommended cable for a very long time...like the 1980's....
Thanks for taking the time Erik.. Always interesting..

Regards
I also see super high ohms in certain regions, Wouldn’t the amp see just that and be down XX db without a notch to bring the impedance down and volume UP.

@oldhvymec

Speaker output is proportional to voltage, and we assume an amp acting as a voltage source with little output impedance, so long as the speakers impedance is high enough ( say > 3 Ohms), raising the speaker impedance to a very high amount like 100 Ohms wont alter the voltage.

Here is one of hundreds of examples of a two way speaker with that xo hump:

https://www.stereophile.com/content/polk-legend-l100-loudspeaker-measurements

Notice the xo impedance hump is not present in the frequency response plot.

There are speaker designers who take more care in order to appeal to tube amp users, like Fritz, and they take extra care to avoid that xo hump. In Fritz’s case, he does so by using serial xo. Others may add an impedance compensation circuit, but since they soak up watts they are big and expensive to make.


But that simple XO in a real speaker isn’t gonna look like that is it?


The first plot on the post i shared was a simulated XO, but the actual XO measures (via DATS v 2) nearly identical so it is absolutely not worth posting. It is the same curve. The trick to getting the camel humps right is to measure the woofer in the cabinet with the port in place. The last two curves in my post are for simple first order filters so you can see how rising impedance blocks unwanted frequencies.
Hello,
Just buy better jumpers. Nordost jumpers are $175. Then run a better single cable if you need it to go to the woofer or bass terminal. Just so you can hear some differences in sound try leaving the jumpers on. Then connect your speaker cables to the high side or tweeter terminals. After that to get a more neutral sound do one black on the bottom and the one red on the top to each speaker. I say get some nice jumpers to start with. Nordost has a reference series set of jumpers too incase you have really expensive gear. This store in the Chicagoland area lets you try before you buy:
https://holmaudio.com/
Try it out first. Also, Let the cables load up for a day or so for a true test. 
PS @oldhvymec

The humps on the left are not a function of the crossover at all.  They are the natural occurrence of the woofer in a ported cabinet. So long as the box, port and woofer are there you'll see that, no coils or caps needed.
So one hump is the driver one is the port and on the right that's the XO right? 

Not 2 ports on the left, Driver and port?

Thanks E

Regards
Hey @oldhvymec

A single driver in free space produces a 1 hump curve, where the peak is called the driver's resonant frequency. You’ll see this in any woofer spec sheet:

https://www.madisoundspeakerstore.com/approx-8-woofers/seas-excel-w22nx001-graph-e0077-8-graphene-co...

Put that woofer (all alone) in a sealed cabinet cabinet and the impedance curve will have 1 hump with a new resonance point.

Add a tweeter with the appropriate crossover and you will have 2 impedance humps. The Magico S1 Mk II for instance:

https://www.soundstagehifi.com/index.php/equipment-reviews/973-magico-s1-mk-ii-loudspeakers

Click on the link near the start of the article and scroll down.  That peak just below 50 Hz is the woofer/cabinet system alone.  The peak above 1kHz is the combination of the low and high pass filter sections.

Now, port that woofer in a cabinet and you’ll get 3 peaks total. The single woofer peak will turn into two. 

Best,

E




@oldhvymec

You might find this discussion useful. In it we go over the impedance of a woofer in a sealed cabinet:


https://speakermakersjourney.blogspot.com/2016/12/crossover-basics-zobel_8.html