Ohms issue bookshelf speakers 6ohms

[geo3]

Use X-sim, it's designed for this.  https://www.diyaudio.com/community/threads/xsim-free-crossover-designer.259865/

 

On 12/4/2023 at 5:01 AM, Heats with Nvidia said:

For example,  why are tweeter and woofer in parallel? This means by definition, that they get the exact same signal and there is no crossover.

Not entirely true. There are series crossovers and parallel crossovers: Here's some diagrams showing the difference  https://sound-au.com/parallel-series.htm

[Heats with Nvidia]

25 minutes ago, geo3 said:

Use X-sim, it's designed for this.  https://www.diyaudio.com/community/threads/xsim-free-crossover-designer.259865/

 

Not entirely true. There are series crossovers and parallel crossovers: Here's some diagrams showing the difference  https://sound-au.com/parallel-series.htm

Parallel in this case means that both terminals of both speakers are directly connected to the terminals of the other speaker. In short, they are both directly connected to the same wires. Which gives them exactly the same signal. So there is no crossover between them. Neither series or parallel crossovers have that feature. One terminal needs to be connected to something else in both of them.

[Kamranbites]

 

Does wire length matter so much?

 

Amazon basic 14-Gauge Speaker wire - 50 feet( left channal bookshelf speaker)

 

Amazon basic 16-Gauge Speaker wire - 1 meter ( right channal bookshelf speaker)

[Heats with Nvidia]

Not really, its fine. At much higher lenghs, much higher power etc... it would but for bookshelf speakers that is totally OK.

[Kamranbites]

So there is nothing to worry about the different lengths for two channels 

[Heats with Nvidia]

34 minutes ago, Kamranbites said:

So there is nothing to worry about the different lengths for two channels 

Correct.

[Kamranbites]

32 minutes ago, Heats with Nvidia said:

Correct.

And what about awg 

 

16 awg is 1 meter (left channel)

14 awg is 50ft (right channel)

 

As we can see there is a difference in  awg will it have any effect  

If not then nothing to worry 

 

but if yes I can change  1 meter  to 14 awg wire for the left channel too 

 

So it will be similar on both sides 

But only if there is some issue.

 

Thanks 

[BuzzingBee]

If I'm reading correctly you want to wire left speaker at 1m, and right speaker at 50 ft (15m)? 

 

For 1m length it doesn't matter what wire gauge it is, 16 vs 14 awg basically makes no difference. 

 

But for 50 ft (15m) length, then yep it starts to matter. I won't lie that there is a bit of power loss, but you made the right call to buy 14 awg cable as it won't have enough audible difference. If you were to purchase say 20 awg for 50 ft, then yeah it's definitely noticeable (I made that mistake before). 

 

So in short you're good. 

[cmndr]

Pretty much all of the electricity will go through and the signals will be preserved. 
It's best practice to use OFC pure copper wire.

As far as "is there a time delay?" Which might be another concern...
Electricity moves at around 270,000,000 m/s

For a length of 50' (16 meters) this is close to instant. Around 6 * 10^-8 seconds. 

 

[Heats with Nvidia]

In short, the longer the wire, the more its diameter and material matter. Its actually good that the longer cable is thicker, so it will have a more similar resistance to the shorter one. Not that it matters that much at these diameters and lenghs.

 

Also real copper is good, CCA (copper clad aluminium), which most cheap cables are, works. The only problem is, that CCA cables are roughly half as conductive as copper cables with the same diameter. Which means that you need cables with double the crossection to get the same results as a pure copper cable. Also they break more easy and are a little harder to solder. But none of these disadvantages should matter in your application too much. By the way, the Amazon basics cable, i can find, is CCA. 

[Kamranbites]

1 hour ago, Heats with Nvidia said:

In short, the longer the wire, the more its diameter and material matter. Its actually good that the longer cable is thicker, so it will have a more similar resistance to the shorter one. Not that it matters that much at these diameters and lenghs.

 

Also real copper is good, CCA (copper clad aluminium), which most cheap cables are, works. The only problem is, that CCA cables are roughly half as conductive as copper cables with the same diameter. Which means that you need cables with double the crossection to get the same results as a pure copper cable. Also they break more easy and are a little harder to solder. But none of these disadvantages should matter in your application too much. By the way, the Amazon basics cable, i can find, is CCA. 

Yes they are cca Copper Clad Aluminium

[cmndr]

15 hours ago, Kamranbites said:

Yes they are cca Copper Clad Aluminium

It won't matter much but in general, it's better to just get thinner copper wires. 

Especially if you're in a humid environment. CCA is prone to corrosion, which screws with electrical conductivity.

Wires don't matter very much, until they do. Mostly if they break (CCA is more prone to this) or corrode. Or if it's SUPER SUPER thin and over a relatively long distance with high signal strength. Audiophiles tend to worry about cabling/wiring more than is needed. My only rules are to stay away from CCA (especially if the wire is going in a wall) and to not get SUPER thin stuff. 

I think I'm using something like this - https://www.amazon.com/AmazonBasics-Speaker-Wire-14-Gauge-Oxygen-Free/dp/B0758CSSF2/

 

The 16 AWG version would also likely be fine. 

[Kamranbites]

10 hours ago, cmndr said:

It won't matter much but in general, it's better to just get thinner copper wires. 

Especially if you're in a humid environment. CCA is prone to corrosion, which screws with electrical conductivity.

Wires don't matter very much, until they do. Mostly if they break (CCA is more prone to this) or corrode. Or if it's SUPER SUPER thin and over a relatively long distance with high signal strength. Audiophiles tend to worry about cabling/wiring more than is needed. My only rules are to stay away from CCA (especially if the wire is going in a wall) and to not get SUPER thin stuff. 

I think I'm using something like this - https://www.amazon.com/AmazonBasics-Speaker-Wire-14-Gauge-Oxygen-Free/dp/B0758CSSF2/

 

The 16 AWG version would also likely be fine. 

I am using this one, and they are not going through walls if they go too I will be making a separate line for this wires 

 

AmazonBasics 14-Gauge Speaker wire - 50 feet https://amzn.eu/d/8UfhESa

[Kamranbites]

Is this correct ?

 

 

(using 

Capacitance = 2.2μF

Tweeter Impedance = 6 ohms

 

Crossover frequency would be approximately 12.12 kHz in this speaker setup.)

 

 

 

 (with a 3.3μF capacitor and a 4-ohm tweeter, the crossover frequency would be approximately 12.12 kHz in this speaker setup.)

[Kamranbites]

What I see is the positive wire goes to 2.2uf capasitor then from there to resistor 3.3ohms 5w then the resistor has one jumper on its both legs then the resistor is connected to tweeter,

Why is that jumper used 

Below attached some pics of crossover and jumper 

[saintlouisbagels]

Does the crossover work? Why are you asking?

[Kamranbites]

Yes it works, just to understand the working and clear some doubts

 

[Kamranbites]

I have pair of bookshelf speakers 6ohms 3 way 

Both when measured shows 6ohms

But one of the speakers suddenly shoes 20-40 ohms 

Is it a problem of concern?

 

After few days it automatically goes to 6ohms but again changes in few days.

 

So I decided to look into it if it had some crossover issue but found nothing.

 

Attaching pic of crossover 

[jaslion]

Like do you hear any sound issues or something?

 

What speakers are these?

 

If they are proper ancient they may have a bad resistor or solder joint

[GOTSpectrum]

 ohm....  ohm....

 

Shhh I'm meditating 

 

On a serious note, I agree with the guy above, do you hear any issues? If not I would say there is nothing to be concerned about 

[Kamranbites]

10 minutes ago, jaslion said:

Like do you hear any sound issues or something?

 

What speakers are these?

 

If they are proper ancient they may have a bad resistor or solder joint

There is no sound issue both speakers sound same not a minor difference

[Kamranbites]

Things I have tried

 

Sorting both terminals and measuring so that any charge left should get discharge

 

Disassembled whole system then checked individual it shows fine

 

Inspecting crossover visually it looks good 

 

 

As said before it doesn't happen all time. Suddenly it shows change for some days and stays same what ever you do it doesn't change 

Then again back to normal 6 ohms 

When it is back to normal what ever you do it stays same 

But once it goes bad suddenly it shows 20-40 ohms and what ever you do it doesn't change 

 

And regarding resistor bad it cannot happen as shared pic you can see resistor has jumper on both legs so it is bypassed i think.

 

Also I have tried on different multimeters so no issue with multimeter

 

The thing of suprise is I have a pair of this speakers one is fine the other one is having this sudden changing ohms issue  but both sound same no minor difference in sound.

 

[Kamranbites]

19 minutes ago, jaslion said:

Like do you hear any sound issues or something?

 

What speakers are these?

 

If they are proper ancient they may have a bad resistor or solder joint

Visually inspecting it doesn't have any issue the working component is capasitor which looks good 

The resistor both legs are connected together which I hole is just bypassed no effect on audio or ohms by it my assumption 

[jaslion]

2 hours ago, Kamranbites said:

There is no sound issue both speakers sound same not a minor difference

Ok then all is good!

[Kamranbites]

41 minutes ago, jaslion said:

Ok then all is good!

But the ohms reading, Instead of 6 it shows 20-30ohms.

Why is that