My cable length and thickness worries me

[deadchip12]

So I'm a newbie and just had people from the local audio store installed a 5.1.4 dolby atmos system inside my bedroom. My setup is jbl stage a130 for front and surround speakers, jbl stage a125c for center speaker, polk v60 for overhead speakers and svs pb-1000 pro for sub. Now for each surround speaker, they ran the cable through the ceiling (to hide them), which leads to the length of the cable becoming pretty long, maybe 15-20m long, but I just checked and that cable was Sommer SP225.2x1.0 (which translates to 1mm thick wire I guess): https://nghenhinviet.com/day-am-tha...-tron-i216838072-s271677083-nl-216838072.html. Is that too thin for that distance, and should I expect a significant degradation in sound quality? I didn't know this before running all the wires and after reading about speaker cable gauge and all that, I'm worried.

 

[-Matt-]

A quick google search suggests that Sommer SP225 has a cross sectional area of 2.5mm² (14 awg).

The cable spec also claims it to be oxygen free copper (which is good rather than copper clad aluminium).

Using this table:

posted in this thread:

Correct speaker wire

Not looking for snake oil but I am looking for the correct speaker wire for my application. I have some very difficult to drive speakers that have significant impedance dips at certain frequencies. It’s been suggested that I should power them with a 250 watt 4 ohm amp but I’m using a 100 watt 8...

www.audiosciencereview.com

...and assuming double your longest cable run 40m (131 feet) (double to account for round trip circuit).

...and the 6 ohm nominal impedance of your JBL a130 speakers.

It looks as though you will see somewhere between 21% and 50% power loss. (So, yes, maybe 14awg is a bit on the skinny side).

Your speakers are still going to work like this - probably with no audiable difference after your AVR has corrected channel levels (<3db).

You can see from the table that upgrading to 12awg likely gets you into the <21% power loss category, whilst upgrading to 10awg will get you below 11% loss.

Personally I think 10awg would be overkill for surrounds (even with long cable runs). I'd listen to the setup with the currently installed wire and see if you ever perceive any problems (at your normal listening levels). If not - then no real need to upgrade to 12awg.

 

[DonH56]

You'll probably be fine for surrounds. Here is another take on wire by Roger Russell, highly-regarded expert in the audio field (and sadly no longer with us): http://www.roger-russell.com/wire/wire.htm Here is a direct link to the wire table: http://www.roger-russell.com/wire/wire.htm#wiretable

HTH - Don

 

[Kal Rubinson]

A quick google search suggests that Sommer SP225 has a cross sectional area of 2.5mm2 (14 awg).

The link in the OP says it is 18 awg.

 

[Spkrdctr]

I also think that you will not have any problems. One question is, how big is your bedroom?

 

[deadchip12]

A quick google search suggests that Sommer SP225 has a cross sectional area of 2.5mm2 (14 awg).

The cable spec also claims it to be oxygen free copper (which is good rather than copper clad aluminium).

Using this table:

posted in this thread:

Correct speaker wire

Not looking for snake oil but I am looking for the correct speaker wire for my application. I have some very difficult to drive speakers that have significant impedance dips at certain frequencies. It’s been suggested that I should power them with a 250 watt 4 ohm amp but I’m using a 100 watt 8...

www.audiosciencereview.com

...and assuming double your longest cable run 40m (131 feet) (double to account for round trip circuit).

...and the 6 ohm nominal impedance of your JBL a130 speakers.

It looks as though you will see somewhere between 21% and 50% power loss. (So, yes, maybe 14awg is a bit on the skinny side).

Your speakers are still going to work like this - probably with no audiable difference after your AVR has corrected channel levels (<3db).

You can see from the table that upgrading to 12awg likely gets you into the <21% power loss category, whilst upgrading to 10awg will get you below 11% loss.

Personally I think 10awg would be overkill for surrounds (even with long cable runs). I'd listen to the setup with the currently installed wire and see if you ever perceive any problems (at your normal listening levels). If not - then no real need to upgrade to 12awg.

Actually the cable I have although the model on the cable says sp225, the wire inside only has cross sectional diameter of 1.0mm, which translates to roughly awg18. It seems to be not a real cable from sommer (the text and logo on the cable look different from what I see on sommer website) but a chinese replica.

 

[deadchip12]

I also think that you will not have any problems. One question is, how big is your bedroom?

The area where I put the speakers inside my bedroom is probably 2.7m x 3.5m, so not very big.

 

[-Matt-]

The link in the OP says it is 18 awg.

You are right but when I search Sommer SP225 on their web shop I only see 2.5mm² wires:

Sommer cable Shop | 9 Hits for "sp225" | purchase online

shop.sommercable.com

It makes a big difference if it is 18awg vs 14awg, but it should be possible for the op to check quickly with a ruler or caliper.

 

[Spkrdctr]

I don't think the wire runs are as long as you guessed. but, it might work out. I'm thinking positive. You will only notice any problems (if any) at pretty high volumes.

 

[-Matt-]

Actually the cable I have although the model on the cable says sp225, the wire inside only has cross sectional diameter of 1.0mm, which translates to roughly awg18. It seems to be not a real cable from sommer (the text and logo on the cable look different from what I see on sommer website) but a chinese replica.

If it measures about 1mm diameter then it may indeed be 18awg, with 1mm² cross sectional area.

Area = π* ((d/2)²)
d = 2*sqrt(Area/π)

14awg:
d = 2*sqrt(2.5mm²/π)= 1.78mm diameter

18awg:
d = 2*sqrt(1mm²/π) = 1.13mm diameter

Best to measure carefully close to where the wire emerges from the insulation.

Edited to include math symbols - still can't figure out how to get sqrt over a bracketed term!

 

[deadchip12]

I don't think the wire runs are as long as you guessed. but, it might work out. I'm thinking positive. You will only notice any problems (if any) at pretty high volumes.

The cables run over the ceiling and I estimated the longest one can be 15-20m.

Since the space is small, I'm sitting pretty close to the speakers so I guess I won't listen at very high volumes.

 

[-Matt-]

Even if it turns out to be 18awg your power loss will be <50% which only equates to a 3dB change in volume. This should easily be handled by AVR calibration.

If the existing wire is of dubious origin then perhaps you also cannot trust that it is pure copper? When you cut the wire do the individual strand ends have an orange copper appearance or a silvery grey look? (Could indicate copper clad aluminium which has slightly higher resistance).

...Even then, it probably won't make much difference for surrounds, but perhaps it would sway me to replace it eventually.

Copper left - CCA right.

 

[deadchip12]

If it measures about 1mm diameter then it may indeed be 18awg, with 1mm² cross sectional area.

Area = π* ((d/2)²)
d = 2*sqrt(Area/π)

14awg:
d = 2*sqrt(2.5mm²/π)= 1.78mm diameter

18awg:
d = 2*sqrt(1mm²/π) = 1.13mm diameter

Best to measure carefully close to where the wire emerges from the insulation.

Edited to include math symbols - still can't figure out how to get sqrt over a bracketed term!

Yeah it seems to be indeed 18awg. I have another 16awg cable that I know for sure is from Sommer with the correct logo and text on the cable just like on the Sommer website, and when i compare that to this one, this one is definitely smaller, so yeah 18awg it is.

 

[DMill]

There is some good news, even if you decide to replace the cables. Now that you already have them run, it's pretty easy to tie one end of the existing cable to a new cable and pull it through. Running cables through ceilings and walls is a pain.

 

[-Matt-]

Hmm, well - it is still going to work ok, but I'd maybe figure out how much replacement with a good quality 14awg or 12awg wire would cost. (Especially if it turns out that your current one is CCA).

(I wouldn't bother with 10awg for surrounds as it is more expensive, harder to handle and can be tricky to fit into connectors.)

 

[deadchip12]

Even if it turns out to be 18awg your power loss will be <50% which only equates to a 3dB change in volume. This should easily be handled by AVR calibration.

If the existing wire is of dubious origin then perhaps you also cannot trust that it is pure copper? When you cut the wire do the individual strand ends have an orange copper appearance of a silvery grey look? (Could indicate copper clad aluminium which has slightly higher resistance).

...Even then, it probably won't make much difference for surrounds, but perhaps it would sway me to replace it eventually.

Copper left - CCA right.

Here are the best pictures I can take. Seems like pure copper, but the strand is so small so not sure if it shows well enough on camera.

 

[deadchip12]

Hmm, well - it is still going to work ok, but I'd maybe figure out how much replacement with a good quality 14awg or 12awg wire would cost. (Especially if it turns out that your current one is CCA).

(I wouldn't bother with 10awg for surrounds as it is more expensive, harder to handle and can be tricky to fit into connectors.)

Per my estimation it will probably cost me roughly 350 dollars to switch to a 80m 14awg non-fake Sommer cable. Not sure if that's worth the increase in sound quality. My speakers are not top tier as you can see above, my room is not treated acoustically either - so basically not a perfect setup already.

 

[Doodski]

Here are the best pictures I can take. Seems like pure copper, but the strand is so small so not sure if it shows well enough on camera.
View attachment 211253
View attachment 211254

View attachment 211255

Ahhh sigh* Glorious copper. We have been recycling copper since Roman times. Just think some of that copper out there in houses and stuff is from Roman times. That's according to a metallurgy book I was reading at the library. I don't see any glint of aluminum in those pics. If you scrape the wire with a knife you should be able to detect more easily if aluminum is present.

 

[Spkrdctr]

It really is a non-issue for your set up. I would just use it as you intended and don't give it another thought. Your volume knob will handle what is required. Your speakers are fine for an entry level surround system and they will actually work VERY well. Everyone has to start somewhere and you really do have a great starter set up. Down the road if you ever get the itch to upgrade (for some reason), then you can use heavier wire and spend more money on your system. For today, I would say you have years of enjoyment ahead of you. Use the system, don't worry about what you have!

 

[-Matt-]

Yep, looks like normal copper to me too.

Per my estimation it will probably cost me roughly 350 dollars to switch to a 80m 14awg non-fake Sommer cable. Not sure if that's worth the increase in sound quality.

It can be pretty much guaranteed that there won't be any change in measured sound quality (at normal listening volumes).

(Although you might well get perceived improvements brought about by the contentment from buying new stuff, fiddling with your gear and due to confirmation bias and psychoacoustics)!

In the end, it is up to you how you choose to spend your money; but I'd try to stop worrying and enjoy the system as it is, at least for a while.