Effect of speaker cable on THD
- Thread starter Alan0354
- Start date
I just finished my amp and did the comparison test with my new cables. I used two cables for each speaker, I use the 5 X 16 gauge in parallel and tape together with electrical tape for tweeter and mid. I use two monster 12 gauge cables in parallel for the woofer for test and comparison between my amp and the Nakamichi PA-7 Stasis.
Last year, I compare my prototype design amp with the Nakamichi, but at the time, I did not know how critical the speaker cables are, I just used Monster 12 gauge cables, on top of it, I used a relay switching fixture to switch one or the other amp to drive the same speaker for comparison. I could not hear any difference between the two amps. But I can tell you from today's comparison, big difference between the two amps. I attribute to the better quality cables and eliminating the relays.
Sure my final amp should be better than the prototype. I use 9 pairs of output transistors vs 5 pairs in the prototype. But the design is similar, I don't expect a huge improvement from the prototype to the final amp today. I really think it's the cable. With good cables, you let the amp shines, bad cables will muddy up the sound and you can't tell the difference.
A lot of people claim that you cannot hear the difference as long as the THD is below 0.1%, I really encourage them to look into their cables. Try build one what I've been talking in this thread, everything I do is cheap, you can make a set of cables for less than $30, just some work. The difference is shocking when I replaced the monster with my 12 X 20 gauge cable.
Last year, I compare my prototype design amp with the Nakamichi, but at the time, I did not know how critical the speaker cables are, I just used Monster 12 gauge cables, on top of it, I used a relay switching fixture to switch one or the other amp to drive the same speaker for comparison. I could not hear any difference between the two amps. But I can tell you from today's comparison, big difference between the two amps. I attribute to the better quality cables and eliminating the relays.
Sure my final amp should be better than the prototype. I use 9 pairs of output transistors vs 5 pairs in the prototype. But the design is similar, I don't expect a huge improvement from the prototype to the final amp today. I really think it's the cable. With good cables, you let the amp shines, bad cables will muddy up the sound and you can't tell the difference.
A lot of people claim that you cannot hear the difference as long as the THD is below 0.1%, I really encourage them to look into their cables. Try build one what I've been talking in this thread, everything I do is cheap, you can make a set of cables for less than $30, just some work. The difference is shocking when I replaced the monster with my 12 X 20 gauge cable.
I did not know that until you mentioned it and I went back to look at the date.
All these are nothing new as many people point out, I just experimented and find a cheap DIY way to get good cable. I am not even claiming it's the best, just a cheap way to get much superior performance than a regular 12 gauge monster cable. And is easy enough for people here to try it out. just about $30 and an hour or so of your time. To me, the better the system, the more critical it is.
All these are nothing new as many people point out, I just experimented and find a cheap DIY way to get good cable. I am not even claiming it's the best, just a cheap way to get much superior performance than a regular 12 gauge monster cable. And is easy enough for people here to try it out. just about $30 and an hour or so of your time. To me, the better the system, the more critical it is.
FYI
I always wondering how come Monster cable put a small plastic tube with the conductors in each wire. I kept have to cut that off as it make the copper wires thicker and harder to fit into the hole of the banana connector. It just dawn on me, that little plastic tube create an inner surface area running the full length of the cable. This will reduce the skin effect a bit because now you have more surface area. The fine copper wires in the cable are twisted into 5 smaller groups so when they twist together with the plastic tube, the tube is always at the center of the conductor to give the maximum benefit.
This is something I don't think they talk about and for us to discover!!!
I always wondering how come Monster cable put a small plastic tube with the conductors in each wire. I kept have to cut that off as it make the copper wires thicker and harder to fit into the hole of the banana connector. It just dawn on me, that little plastic tube create an inner surface area running the full length of the cable. This will reduce the skin effect a bit because now you have more surface area. The fine copper wires in the cable are twisted into 5 smaller groups so when they twist together with the plastic tube, the tube is always at the center of the conductor to give the maximum benefit.
This is something I don't think they talk about and for us to discover!!!
restorer-john
Addicted Member
Alan, your braided cable design (with multiple smaller connectors twisted together) is identical to the design that Kenwood came up with after extensive research in the 1970s. I would pursue that cable design more- I think you are on the right track. 
I think my venture with the cable is coming to an end, where I draw the line is if I have to go into difficult process in making and/or start using expensive materials. I want to try to make it in the way that people can easily make it. I read about some people "knit" the smaller cables together to get the best coupling to reduce inductance. That's is not practical to me. Also, as you twist the wires tighter and tighter together and/or using more wires in parallel, capacitance goes up. I measured my cables, they are all in 2200pF to 2700pF/12ft. Some amps might not be able to handle this high capacitance.
I finally took out the Nakamichi and put it on the bench and put it through the ringer, It cannot even take 1500pF across the output connector at the back of the amp!!!! It will oscillate with any capacitor over 1000pF. So if you have a cable that is 6000pF, it's not going to work.
I think what I have so far, it's not the best, nothing that innovative, but anyone that is curious about cable can make it and try it for themselves. It's less than $20 to make two cables, and it sure beat the 12 gauge Monster cable by a mile.
From this experience, I am quite convinced that Mono Block is the way to go, you cut the cable length down to like 3ft or so. With the experience testing my amp, I think a good speaker cable is as important as a good amp. If you don't have a good amp, cable doesn't matter. But if you have a good amp that has very low THD, the cable can make or break the system. In the former post in this thread, I talked about the difference it make using the 10X20 gauge twisted cable compare to two pairs of 12 gauge monster cable. I can tell the the improvement of changing the cable is slightly bigger than going from the Nakamichi Stasis to my amp......that I pulled out all stops to lower THD and literally run in Class A at normal listening level. It is that big an improvement just with a $20 investment.
I cannot help but to think people that claimed it won't make any difference in the sound quality as long as the THD is better than 0.1%, that they should look at their cables. 10ft of 12 gauge Monster cable raise the THD from 0.006% to 0.14% from my testing as recorded in this thread. Of cause you cannot hear the difference as long as the THD of the amp is below 0.1%. The cable easily drown the amp with distortion already. Particularly some people here using the instruction from an amp manufacturer that it's ok to use 14 or 16 gauge cable if it is under certain length. To me cable is everything for a good system.
I measured the Nakamichi, THD is 0.04% at all frequencies. This compare to my amp that is from 0.001% to 0.0035% worst case. With my cable, I definitely can hear the difference, more separation, more detail, you can hear all the small sound clearer, also it's like the music source is closer to you. I bet, the sound will go to another level if I go mono block where I can use short cable.
I finally took out the Nakamichi and put it on the bench and put it through the ringer, It cannot even take 1500pF across the output connector at the back of the amp!!!! It will oscillate with any capacitor over 1000pF. So if you have a cable that is 6000pF, it's not going to work.
I think what I have so far, it's not the best, nothing that innovative, but anyone that is curious about cable can make it and try it for themselves. It's less than $20 to make two cables, and it sure beat the 12 gauge Monster cable by a mile.
From this experience, I am quite convinced that Mono Block is the way to go, you cut the cable length down to like 3ft or so. With the experience testing my amp, I think a good speaker cable is as important as a good amp. If you don't have a good amp, cable doesn't matter. But if you have a good amp that has very low THD, the cable can make or break the system. In the former post in this thread, I talked about the difference it make using the 10X20 gauge twisted cable compare to two pairs of 12 gauge monster cable. I can tell the the improvement of changing the cable is slightly bigger than going from the Nakamichi Stasis to my amp......that I pulled out all stops to lower THD and literally run in Class A at normal listening level. It is that big an improvement just with a $20 investment.
I cannot help but to think people that claimed it won't make any difference in the sound quality as long as the THD is better than 0.1%, that they should look at their cables. 10ft of 12 gauge Monster cable raise the THD from 0.006% to 0.14% from my testing as recorded in this thread. Of cause you cannot hear the difference as long as the THD of the amp is below 0.1%. The cable easily drown the amp with distortion already. Particularly some people here using the instruction from an amp manufacturer that it's ok to use 14 or 16 gauge cable if it is under certain length. To me cable is everything for a good system.
I measured the Nakamichi, THD is 0.04% at all frequencies. This compare to my amp that is from 0.001% to 0.0035% worst case. With my cable, I definitely can hear the difference, more separation, more detail, you can hear all the small sound clearer, also it's like the music source is closer to you. I bet, the sound will go to another level if I go mono block where I can use short cable.
Binkman
Lunatic Member
And yes noted by many.. including me, other forums, etc. Good example is our down under mates like 'restorer john' et-al who have done similar experiments. Alan; you reflect on mono blocks, too. So in short my simple experiments with pretty good drivers, low thd amps is all in my immediate setup. There is no question with so many threads I've read where a poster has immediately heard improvement with speaker and audio input cables to scoff at (as many have read many scoffs, too.) Even many many engineers agree that audio is a very complex past time or profession. repair or new not to mention ("not a cheap hobby or prof.)
Referring to human audio response, in person auditioning, some speaker builders from single driver to 3 way stereo all agree that positioning is a huge factor even to a few degrees of inward or outward to height of a woofer off the floor.. Then the battle of the living room.. your stereo doesn't match the decor.. your banned to the basement or the garage.. forever!! The aside of the species.. the female has two senses (plus intuition) that is smell and hearing. So when you say under your breath after the verdict.. and she says "what did you say?" you say you said" I gotta frigging itch" and reach back to scratch your back.
You're going for as low thd you can 'establish' on a graph.. and probably pretty good as per averages in readings. Just want to add thanks for the 'blow by blow' reporting. I also thought that looking at the last layout pic you posted, you might want to shield the power supply. add a small fan if needed and close the box up then measure. I can affirm my experience with chambers and testing with engineers who specialized on all frequencies and isolation. Again your testing is probably pretty good numbers wise.. all of our instruments aren't 'empirical' and written in granite.
bink
Referring to human audio response, in person auditioning, some speaker builders from single driver to 3 way stereo all agree that positioning is a huge factor even to a few degrees of inward or outward to height of a woofer off the floor.. Then the battle of the living room.. your stereo doesn't match the decor.. your banned to the basement or the garage.. forever!!
The aside of the species.. the female has two senses (plus intuition) that is smell and hearing. So when you say under your breath after the verdict.. and she says "what did you say?" you say you said" I gotta frigging itch" and reach back to scratch your back. You're going for as low thd you can 'establish' on a graph.. and probably pretty good as per averages in readings. Just want to add thanks for the 'blow by blow' reporting. I also thought that looking at the last layout pic you posted, you might want to shield the power supply. add a small fan if needed and close the box up then measure. I can affirm my experience with chambers and testing with engineers who specialized on all frequencies and isolation. Again your testing is probably pretty good numbers wise.. all of our instruments aren't 'empirical' and written in granite.
bink
The room is definitely a very important factor. BUT, the problem is it is usually out of our control. You have the big boss to answer to as you said already. Also, you do live in the place, you really cannot make it into a studio. Acoustic panel do help......BUT it's an eye sorer. I had one that help to bring out the bottom and better bass. But it is in a place it's not nice looking. Big boss complain, the last straw was she want to vacuum around the area and the panel was in her way of the electrical outlet. The panel is in the closet now!!!!
My experience from moving into 3 different houses with the same system is the quality of the system do matter. My original Kef floor standing with the Acurus is not going to be better than my existing system no matter how you optimize the room with panels and all, not even close. Unless all of a sudden you move into a town hall size room with no carpet and all, I can only give the room 30% or so to the quality of the sound, still more than half is the system. The bass and the bottom is still better with the new Rythmik without the panel than my old Velodyne 10" + the panel.
Over all, the speakers are the ones define the sound and quality of the system, nothing affect the sound more than changing the speakers. I still need to play with more to form my opinion of how important is the amp and THD, but my first experience sway me to believe THD of the amp is very important. I really would like to have a chance to try a single end tube mono block in my setup, an Aleph by Nelson Pass and a good push pull tube amp. But where to I find these amps to try it in my house with my speakers unless I build them!!!
My experience from moving into 3 different houses with the same system is the quality of the system do matter. My original Kef floor standing with the Acurus is not going to be better than my existing system no matter how you optimize the room with panels and all, not even close. Unless all of a sudden you move into a town hall size room with no carpet and all, I can only give the room 30% or so to the quality of the sound, still more than half is the system. The bass and the bottom is still better with the new Rythmik without the panel than my old Velodyne 10" + the panel.
Over all, the speakers are the ones define the sound and quality of the system, nothing affect the sound more than changing the speakers. I still need to play with more to form my opinion of how important is the amp and THD, but my first experience sway me to believe THD of the amp is very important. I really would like to have a chance to try a single end tube mono block in my setup, an Aleph by Nelson Pass and a good push pull tube amp. But where to I find these amps to try it in my house with my speakers unless I build them!!!
Binkman
Lunatic Member
For audio 'quality listening' and low thd is a mark of good design. but don't forget the factory testing is with an ideal load rated wattage and I'm sure the engineers calculated the load etc.. Again our aussie mates can typically run a simple tube 10w set up and nice speakers etc.. even one guy said he runs 3watts on his horns and the listening db would become annoying and 10watts tube can sound like 35watts or drown out conversation at a party or small pub. e.g. how loud is annoying in a club? db meter would close most clubs.
Back to speakers and design to reproduce the sound/ image requires an amp that is quite heavy and complicated. Best thd designs i.e. have 2 stages of emitter follower design to filter the input clean, and as noted the mosfets and other good pots quality etc. built in with a mother transformer. Onkyo might be something to look for on the west coast for older stuff with mosfets. pretty good thd references as onkyo tested thd at rated output. west coast got a lot more units shipped than to the east so more available.
Back to speakers and design to reproduce the sound/ image requires an amp that is quite heavy and complicated. Best thd designs i.e. have 2 stages of emitter follower design to filter the input clean, and as noted the mosfets and other good pots quality etc. built in with a mother transformer. Onkyo might be something to look for on the west coast for older stuff with mosfets. pretty good thd references as onkyo tested thd at rated output. west coast got a lot more units shipped than to the east so more available.
Just to update in this thread, I am building a second amp. I want to experiment running monoblock. The only reason for doing this is to be able to use a 4ft speaker cable instead of the 12ft cable I have to put up with. I am hoping to hear a difference even though the second amp is just a smaller lower power version of the first amp.
jozeppy26
Active Member
Woooooooooooooooooooow. 
I’m currently using very cheap and plain bare 16 gauge speaker wire. From reading this forum (and admittedly only understanding 2% of it) I have gathered that at the very least I should be using the shortest 12 gauge better insulated speaker wire possible considering my receiver THD is 0.005%? And I shouldn’t use multiple parallel thinner gauge speaker wire bc of the increased capacitance? And I should stay away from banana plugs.
I’m currently using very cheap and plain bare 16 gauge speaker wire. From reading this forum (and admittedly only understanding 2% of it) I have gathered that at the very least I should be using the shortest 12 gauge better insulated speaker wire possible considering my receiver THD is 0.005%? And I shouldn’t use multiple parallel thinner gauge speaker wire bc of the increased capacitance? And I should stay away from banana plugs.
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I think you should use multiple thinner gauge speaker wire. It is cheap to experiment it. I just got 100ft of this and built a pair of 9ft long cables.http://www.ebay.com/itm/100-feet-TR...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649 .All my tests are against the Monster 12gauge cable, you can see so much improvement using the cable I made over the Monster cable.
http://www.ebay.com/itm/100-feet-TR...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
I have no problem using banana plugs. I don't think I ever said not to use banana plugs because I am using it!!!
Post #203 here showed how I make my cables BUT you can see later on, I change to 16 gauge wires and use 5 pairs in parallel. But the method of making is the same:http://audiokarma.org/forums/index.php?threads/effect-of-speaker-cable-on-thd.764633/page-11
If you have an amp that is 0.005% THD, if will make a big difference when you switch to this cable.
http://www.ebay.com/itm/100-feet-TR...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
I have no problem using banana plugs. I don't think I ever said not to use banana plugs because I am using it!!!
Post #203 here showed how I make my cables BUT you can see later on, I change to 16 gauge wires and use 5 pairs in parallel. But the method of making is the same:http://audiokarma.org/forums/index.php?threads/effect-of-speaker-cable-on-thd.764633/page-11
If you have an amp that is 0.005% THD, if will make a big difference when you switch to this cable.
jozeppy26
Active Member
Ok actually I see where you say that per speaker you use a 5x16 twisted in parallel for tweeter and mid and then 12 gauge cable for woofer. That’s a bit advanced for me I think to separate the woofer wiring and solder to new woofer-only binding posts and yada yada yada. What was the final capacitance of the 5x16 big daddy cable and is it something any typical amp can handle? I’d be using it with a pioneer SX-3900
That's a good question whether the amp can handle that. You just have to try and see. Don't assume it cannot take it. IT's only $11 to try it. I already gone to 16gauge to reduce capacitance. It's about 2500pF for 10ft long. So make it short as possible.
The cables are in red/black pair. It's very important as it's the close coupling that reduced the series inductance and reduce THD.
Using smaller gauge and more pairs is to eliminate skin effect. Unlike people think that this is only audio frequency and don't worry about skin effect. I did calculation and it matters. If to cut the Monster cable open, you'll se they put a plastic round core in the middle of the copper wires to create an inner surface to give you two skin depth. That's actually a clever idea.
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vzaichenko
New Member
Hi All,
Greetings from diyaudio.com
Here are my 2 cents to the point:
Speaker cables don't influence harmonic distortion!
If your measurements show THD increase with the cable in place - you've got an "unwanted" ground connection at the far end of the cable (through your measurement equipment).
Remove it, make sure the analyzer's input is fully AC-coupled, and you will see the real picture.
I'm not saying the speaker cable's quality does not influence the sound quality - it does in most cases, but it does not influence THD. Cables are linear
Unless an amplifier goes unstable because of the cable's capacitance - but that's a different story. I'm talking about the good amplifiers.
Cheers,
Valery
Greetings from diyaudio.com
Here are my 2 cents to the point:
Speaker cables don't influence harmonic distortion!
If your measurements show THD increase with the cable in place - you've got an "unwanted" ground connection at the far end of the cable (through your measurement equipment).
Remove it, make sure the analyzer's input is fully AC-coupled, and you will see the real picture.
I'm not saying the speaker cable's quality does not influence the sound quality - it does in most cases, but it does not influence THD. Cables are linear
Unless an amplifier goes unstable because of the cable's capacitance - but that's a different story. I'm talking about the good amplifiers.
Cheers,
Valery
roger2
.
Welcome @vzaichenko 
Actually Monster has promoted that but not for many years.
I believe we are local to each other and if you want to try independent verification I'll be happy to help. I'm pretty well equipped.
Demian
