Is LS3/5A 15 ohms speaker better than the 11 ohms LS3/5A speaker?

[Rancho]

Audiophile expert,

 

Anyone can advise me if the 15 ohms LS3/5A is better than the 11 ohms LS3/5A speakers?

 

Do I need a high power intergrated amplifier to drive a 15 ohms speakers?

 

Currently, all the new 11 ohms LS3/5A speakers are made in China. Is the new LS3/5A 15 ohms speakers also made in China?

 

Appreciate someone can advise me accordingly.

 

Thank you so much.

[Audio]

In this day and age, speaker load should be as low as possible....4 ohm is norminal, but not as crazy low as 1 ohm.

 

That is to say, a 11 ohms speaker would be better and easier to drive than a 15 ohm speaker.

 

(Audio)

[Guest ghemml]

Depending on the True Output Impedance of your amp. Generally solid state amp should be much issue.

[GAGAecholoft]

In this day and age, speaker load should be as low as possible....4 ohm is norminal, but not as crazy low as 1 ohm.

 

That is to say, a 11 ohms speaker would be better and easier to drive than a 15 ohm speaker.

 

(Audio)

hi, don't quite catch the principle....care to elaborate? amplifier output impedance aside, why would u say a lower impedance speaker is easier to drive than a higher impedance one? with this statement, you have really woke me up from my after lunch doze..... ;D

[joamonte]

Audiophile expert,

 

Anyone can advise me if the 15 ohms LS3/5A is better than the 11 ohms LS3/5A speakers?

 

Do I need a high power intergrated amplifier to drive a 15 ohms speakers?

 

Currently, all the new 11 ohms LS3/5A speakers are made in China. Is the new LS3/5A 15 ohms speakers also made in China?

 

Appreciate someone can advise me accordingly.

 

Thank you so much.

 

XP LS 3/5a expert , Luohan and lieu , where are you ?  ;D

 

just to share.

 

1)Most LS 3/5a collector I know own more 15 ohm than 11 ohm , some 10/20 pairs of 15 ohm and only 1 or 2 pair of 11 ohm...

 

2) In Ebay , the average final biding price of 15 ohm is double or even triple of 11 ohm model.....other than rare case like KEF black piano , Harberth Gold tweeter, Roger 60th anniversary , Rogers 50th anniversary , most 11 ohm final biding price is cheaper than a pair of new current production China Rogers LS3/5a.

 

3)Strictly speaker, China LS 3/5a is not real LS 3/5a , its woofer and tweeter are make in China cloning the original KEFs driver , and the box is make of MDF ( Original LS 3/5a is plywood) , no matter the sound how close to original LS 3/5a , it is still not LS 3/5a.

 

 

So is 15 ohm sound better than 11 ohm? I cannot say yes , because a lot of 11 ohm owner will be very unhappy if somebody say that , ;)  but after own and compare a few pair of11 ohm and 15 ohm LS 3/5a, I currently keeping 3 pair of 15 ohm not only for listening , but also for investment ....... I almost never lost money selling LS 3/5a , every few year the Vintage 15 ohm LS 3/5a value increase(can't say the same for 11 ohm model) ,  where to find such audio product, can play, can listen and can maintain its resale value?

[Rancho]

Wow! really appreciate the overwhelming response on this topic.

 

So the LS3/5A 15 ohms is a collector's item.

 

Is it true that all 15 Ohms LS3/5A speakers are made in UK and none made in China? If yes, why? For if it is a sought after item, the China man will want to clone it and make money.

 

Next question comes to my mind is, which is better... Harbeth, Roger, Chartwell, Spendor or maybe more. Which one is the actual collector's brand sought after?

 

Please educate me.

 

Thank you all so so much.

 

Kind regards.

[Guest ghemml]

The 1st LS3/5A is design in 1970s.

 

Even the drivers from KEF are no longer in production for donkey years, otherwise I buy one pellet off from Martin and sell them in ebay.

[joamonte]

http://www.xtremeplace.com/yabbse/index.php?topic=109577.msg762329;topicseen#msg762329

[Audio]

Akyah, no need to be amazed in what I said, I just answer the question from a technical point of view.

 

Did I say anything about SOUNDING BETTER?  All I said is that lower the impedance , the easier to drive.

 

I own a pair of Roger LS3 /5A in the 80s and I know what's it like.  Keep clipping the speaker, yes, sounded good but not on everything and always clip when pressed hard.  Poor B110 woofer!!  Not the speakers'fault, but being 16 ohms, it is difficult to make it sound loud.

 

So, natually my next speaker back then was the Kef Reference 104 Mark II....6 ohms, easy to crank up the volume and blast!!

 

(Audio)

 

 

[GAGAecholoft]

Akyah, no need to be amazed in what I said, I just answer the question from a technical point of view.

 

Did I say anything about SOUNDING BETTER?  All I said is that lower the impedance , the easier to drive.

 

I own a pair of Roger LS3 /5A in the 80s and I know what's it like.  Keep clipping the speaker, yes, sounded good but not on everything and always clip when pressed hard.  Poor B110 woofer!!  Not the speakers'fault, but being 16 ohms, it is difficult to make it sound loud.

 

So, natually my next speaker back then was the Kef Reference 104 Mark II....6 ohms, easy to crank up the volume and blast!!

 

(Audio)

 

 

 

if u have not realised, i am also asking from the technical point of view. nothing to do with sounding better or worse. So tell me, why do u say eg. 16 ohm speakers are 'more difficult' to drive than say a pair of 4 ohm ones. I am not amazed by what u said - just surprised by the principle u mentioned. Care to enlighten me from the technical point of view?

[Audio]

OK....

 

Say an good modern power amplifer with good current rating is outputting a 10V peak-to-peak sine wave signal.

 

If both speakers' efficiencies are the same, the lower impedance speaker will produce a louder volume, because of the lower impedance, it draws a higher current and dissipate a higher power.

 

Another thing, to make the higher impedance speaker sounds louder, you need to increase the voltage swing of the power amp's output and in doing so, your amp will clip first with the higher impedance speaker than with the lower impedance one. 

 

So, with lower impedance speaker, for all things equal, you have a louder volume and you will be able to make better use of the voltage swing that are available to you from your amp than with a high impedance speaker.

 

Logical?  (Flame suit on....)  :)

 

(Audio)

 

This is a real life situation, I always enjoy my Rogers LS3/5A but when I up the volume, it often clipped before I reach the desired shiokness.  I actually damaged one of the B110 due to overheating the resin at the voice coil.  Dammn hard speaker to drive...get them repaired at Atlas Sound.  I have no problem when I got the KEF using the same power amps.

[Audio]

Same thing with headphones.......

 

All the 16 ohms headphones are easy to drive, iPad, iPod, Iphone or smartphone can drive them to be deafing loud.....try doing the same for a 300 ohm HD-800 headphone.

 

(Audio)

[flowerpot]

actually lower ohm is harder to drive...

[Audio]

actually lower ohm is harder to drive...

 

Not when you are comparing a 15 ohm speakers with a 11 ohm speaker.

 

With modern amps, it's actually no issue driving 4 ohms speakers.......

 

It only gets more difficult when you starting approaching as low as 1 to half ohm.......  :)

 

(Audio)

 

[malsound]

Sorry for take this a little off channel, I have heard with first ear experience with 2 model of AVG horn 18ohm Omega series with Airtight 211 and 300B before 8 ohm and after tapping to 16 ohm. In both cases 16 tap win by a ang moh nose, one longer than the other. ;D

 

Everything sound calmer, more compose. Not that it sound confusing in the first place. Not sure the same can be heard with the 15ohm 35a  but I do remember some old amp like audio innovation has a 15 ohm tap.

 

 

[Guest james46]

Just wondering if 15 ohm sounds better why don't all the people make 15 ohm as a standard?

[Guest ghemml]

Regardless of impedance, the sensitivity is more important.

 

One reason I can understand for the high impedance is to prevent the amp e.g. class A amp from dying.

[Doggie Howser]

actually lower ohm is harder to drive...

 

I think Audio is approaching it using a different perspective. He's suggesting that if you have a powerful enough amp so the low impedance issue is taken care of, the higher input impedance prevents you from driving the speakers loud. That is a fascinating take on it.

 

 

[joamonte]

Bare in mind that LS3/5a in the beginning is design for monitoring voice in a small enclose area , like inside a Van mobile mixing room or a HDB toilet size monitor room...the BBC engineer never meant to use it listen music, 15 ohm is not a problem because they have a standard transistor amp (make by Quad) to match with it , and the "standard" BBC LS3/5a terminator is using XLR connector for space, safety and easy pluging reason (MIGHT be a reason for higher impedance design)...pls remember it is a just a grade B monitor that "not qualify" as music monitoring,to BBC , it only can be use to check the recording quality of human's speaking for their radio broadcasting.

 

My guess is some audiophile in the 70's , 80's that using tube amp with the 16ohm output tap accidently discover how good the sound from this speaker, and when more and more home user buy the speaker and drive with solid state amp, BBC/KEF change the design to 11 ohm so that it is more suitable for the budget SS amp...

 

The official reason BBC change the design to 11 ohm in 1989 is because the 15 ohm design KEF woofer (8 ohm) encounter high rejected rate , so they have to redesign the woofer , the new woofer impedance drop to average 6 ohm, so KEF  have to redesign the crossover , hence the overall impedance of the speaker become 11 ohm.

 

James , the main attractive point about 15 ohm model is that their crossover are made by different company, despite the values and circuit are the same, but different brand 15 ohm using different component, 11 ohm model all crossover are made by KEF.......and the 11 ohm crossover is not design by BBC famous engineer team , it is design by KEF, while I respect the KEF engineer knowledge, I think you also agree that KEF do not have too much great small speaker in their history ( ok 104/105 is good in old day , but those are floor stander, their own coda small speaker never really made it  :P )

[joamonte]

One more thing to add.....

 

Another reason why earlier 15 ohm LS3/5a have better resale value is because in those days, 70/80s or earlier higher price Hifi are made to last, the maker put in effort in the built quality and workmanship, if you compare the veneer and parts of a good condition 70's Chartwell or Rogers Gold Tag, with the 90's Rogers 11 ohm model, you will realize the later component use is really cheapskate and the cabinet is not as solid, even the veneer don't look as nice....

 

The reason why 11 ohm Harberth usually can get better biding price is because Harberth have the best workmanship of all 11 ohm batch.

[Audio]

I hope by now, most of you should know that how good a speaker or headphone would sound has nothing to do with their impedance.  Don't waste your sleep and worry about such things.  The designers would have done their homework when it comes to this as most power amp nowadays should be able to drive most speaker loads.

 

My prospective was taken from my experience with the Rogers LS3/5A and I experienced first hand the issues with it.

 

It also come with dealing with headphone issues at work.  As you are well aware, the airlines introduce electrical headphones for use in the late 80s and a good design would be one with a high impedance because:-

 

(1) We don't have cost effective, small and powerful magnets as we have today.

 

(2) The DC supply of aircraft electrical system is 28VDC so, we don't have voltage limitations like what car and other transportation vehicle faces with supply voltage limited to 12VDC.

 

(3)  A high impedance headphones will consume less current and will be a good safety consideration.

 

Hence almost all airlines headphones are spec at 300 ohms.  Now imagine what happened when you fit in your everyday 16 Ohms headphones into the system, it will sound very, very loud.  This is the reason why Bose Noise cancellation headphones comes with 2 gain settings.....and the more expensive UE (Logitech) has an special attenuator attachment to be used when the earphones is plug onto the aircraft system.

 

Another thing is because the low impedance headphones is so efficient, which means it is more sensitive, the residue noise of the aircraft sound system (buzz, hiss, 400Hz aircraft AC supply pickup) will be heard more clearly and loudly then from a pair of high impedance insensitive headphones. 

 

And because your iPad , ipod, Iphones and other mobile devices have limited supply voltage, that is why your everyday headphones / earphones need to have a low impedance or else it will not sound loud enough.  Some Audiophile headphones are still designed with high impedance because they expect you to use a good headphone amp to drive it.....one with higher supply voltage or one with a switching power supply.

 

So, what speakers and headphones are easier to drive??  Low Impedance ones and please don't lose sleep over it.  We, after all, are already in the 21st century...... 

 

(Audio)

 

[jeromelang]

I hope by now, most of you should know that how good a speaker or headphone would sound has nothing to do with their impedance.  Don't waste your sleep and worry about such things.  The designers would have done their homework when it comes to this as most power amp nowadays should be able to drive most speaker loads.

 

My prospective was taken from my experience with the Rogers LS3/5A and I experienced first hand the issues with it.

 

It also come with dealing with headphone issues at work.  As you are well aware, the airlines introduce electrical headphones for use in the late 80s and a good design would be one with a high impedance because:-

 

(1) We don't have cost effective, small and powerful magnets as we have today.

 

(2) The DC supply of aircraft electrical system is 28VDC so, we don't have voltage limitations like what car and other transportation vehicle faces with supply voltage limited to 12VDC.

 

(3)  A high impedance headphones will consume less current and will be a good safety consideration.

 

Hence almost all airlines headphones are spec at 300 ohms.  Now imagine what happened when you fit in your everyday 16 Ohms headphones into the system, it will sound very, very loud.  This is the reason why Bose Noise cancellation headphones comes with 2 gain settings.....and the more expensive UE (Logitech) has an special attenuator attachment to be used when the earphones is plug onto the aircraft system.

 

Another thing is because the low impedance headphones is so efficient, which means it is more sensitive, the residue noise of the aircraft sound system (buzz, hiss, 400Hz aircraft AC supply pickup) will be heard more clearly and loudly then from a pair of high impedance insensitive headphones. 

 

And because your iPad , ipod, Iphones and other mobile devices have limited supply voltage, that is why your everyday headphones / earphones need to have a low impedance or else it will not sound loud enough.  Some Audiophile headphones are still designed with high impedance because they expect you to use a good headphone amp to drive it.....one with higher supply voltage or one with a switching power supply.

 

So, what speakers and headphones are easier to drive??  Low Impedance ones and please don't lose sleep over it.  We, after all, are already in the 21st century...... 

 

(Audio)

 

 

[Guest james46]

Thats what I thought that in general impedance have nothing to do with sound quality.

[flowerpot]

Low impedance is easier to drive is wrong im afriad... not here to prove anything but is a matter of fact low imepdance as seen by the amp is harder to drive....

 

A simple fact is low imepdance draws much higher current, the amp have to source more current just to drive the speakers to the same level as a higher imedance load...

 

Thats why you see power ratings of 50W@8ohm, 100W@4ohm etc... The very reason being the amp is having to pump out more power to drive the lower imepance load....

 

A simple ohms law even tell you that a higher imedance load will see a higher voltage across it as compare to a lower impedance load...

 

Also the output impedance of the amp is often preferred to be as low as possible... so that the speakers impedance is "significantly higer"

 

If the theory of lower impedance is eaiser to drive is true than i be glad to buy the HE-6 to use it on my iphone... 

[FG Chong]

Low impedance is easier to drive is wrong im afriad... not here to prove anything but is a matter of fact low imepdance as seen by the amp is harder to drive....

 

A simple fact is low imepdance draws much higher current, the amp have to source more current just to drive the speakers to the same level as a higher imedance load...

 

Thats why you see power ratings of 50W@8ohm, 100W@4ohm etc... The very reason being the amp is having to pump out more power to drive the lower imepance load....

 

A simple ohms law even tell you that a higher imedance load will see a higher voltage across it as compare to a lower impedance load...

 

Also the output impedance of the amp is often preferred to be as low as possible... so that the speakers impedance is "significantly higer"

 

If the theory of lower impedance is eaiser to drive is true than i be glad to buy the HE-6 to use it on my iphone... 

 

+1.  Another point to add on is that impedance varies with frequency.  What is stated on the speaker is nominal impedance and depending on design of the speaker, the actual impedance at lower frequency can dip to very low,  thus drawing very high current from the amplifier and can result the clipping of the amplifier, causing damage to the speaker and or amplifier itself.