Rogers LS3/5a question


I am a pro audio guy and know very little about hi-fi stuff. I was at an estate sale today and found a pair of Rogers Ls3's for a VERY good price. They were built in 1079 and the construction is some of the best I have ever seen in a speaker. The problem is that they are 15 ohms and I really don't have anything to power them. I do not want to damage them by hooking them up to something I shouldn't. I would love to hear them and make sure everything works properly. From what I gather from a little research is that the mid-range is incredible. If they are better than my reference monitors I will keep them, if not they will be sold. Thanks for your help guys!
stellastudios
They have very good midrange, but a "bumped up" bass response.

The Rogers Ls3/5 is a "classic" small room speaker. Do not over drive them with too much power! About 50 watts max.

Most all solid state amps will drive them well. They also work well with tube amps due to the 15 ohm load.
I've owned Rogers and a myriad of British speakers. These do not need a great deal of wattage, however they do need very stable current. It is correct that they love tubes because the 15 ohm presents an easy load. However, hook these up to a 100 wpc Pioneer receiver and it will be dreadful. This is why the NAD 3020 was such a good match with its stable current.

British integrated amps such as Exposure, Sugden and Quad easily drive these and control the tiny woofer. Rogers are wonderfully colored and musical with vocals and acoustic instruments. 24" massed stands are a must. Enjoy a classic.
These were my first "high end" speakers back in the late seventies. I had them hard wired with Fulton brown speaker wire(one of the first audiophile cables).
Don gives a nice description of their sound. They also have a nice jump/aliveness to their sound.
I used a Stereo 70 then a Bedini 25/25(25watts/ class A) then a conrad-johnson MV50. Stay with best 20-50 watts/ch that you can afford.

As an aside it would interesting to hear them with an OTL like an Atmasphere S30 or SET like the Cary 805 which were not available at that time.
Be informed that they are very in-efficient speakers, only about 83 db sensitivity. With that said, they need a well built amplifier sections to make them really sing. Nevertheless they are absolutely wonderful little speakers.
(Those more knowledgeable, please correct me if my memory is faulty on this.) If you're looking for "ruthlessly revealing" monitors for recording/mastering, the LS 3/5a may not be ideal. While intended for use as monitors, they were designed by the BBC (IIRC) for mobile-recording situations, i.e., mobile vans, etc. They were also (again IIRC) designed for monitoring the human voice. They are famous for a mid-bass bump to give the illusion of deeper bass. Thus, they are not the flattest of monitors. None of this prevented them from being enormously popular and beloved in the audiophile community. Sorry I can't give you any advice on amplification.
-Bob
I had two pairs of Rogers at various times. They are subjectively very flat and terrific for solo voice, guitar, violin, small emsembles, but due to sensitivity issue will not play extremely loud and are comparatively speaking undynamic. So for large scale orchestras and rock they are not the best choice. Recommend tube amp 20-50 watts for best results.
I think any quality amplifier will drive the 15ohm Rogers with no risk to the speaker. Just use common sense and no wide open volume pots! I have a pair for over twenty-five years and have driven them with a Dynaco Stereo 70, Bedini 25/25, Quattre DGC-250 (solid state), Bryston 4B (solid state), NAD 3020 (solid state) and McCormack DNA-125 (also solid state). I have never experienced a problem with any of the set ups. The tubes were wonderful with them - seemed to ease the mid-bass bump a bit. Of the solid states, the McCormack was the hands down winner - almost fooled you into thinking it was tube. Hope this helps. Enjoy the little guys.
I had a pair also back in 1980, the Swisstone models with the 15 ohm inputs.

A NAD 3020 and a Dynaco Stereo 70 made them sound quite nice.

But I was a musician at the time,and they just didn't have enough bass for me, and no sub at that time ever really matched up.

They imaged quite well, by that you got good spacing and layering of the players on the recording, but it was all miniature.

I sold them and went to Acoustat 3 medallian and this was closer to what my musician wants were at the time.

The deal closer for me was when I took the LS3/5A out of a small room into a large room. They just didn't do it anymore.
If you want to use them as monitors, keep them in a small space and you maybe quite pleased.
Those are ok speakers but...
If you want to just get rid of them let me know.
*s*

PS. Hook em up to just about anything of decent quality and you'll be able to see if they are ok. If you are running "reference" monitors, then you certainly must have something good driving them. Just take those out and slip the Rogers into their place and you'll see right away if you like them.
I have had a pair of Rogers LS3/5a speakers since 1985. Originally powered by Belles Model One (100 watts per channel amp). As long as you do not over drive them with a 100 watt amp they work great.

I now use a Fisher 400 receiver that sounds wonderful with these speakers. I use them in a Great Room that is 25'x18'x16' with hard wood floors. What is it you are trying to drive them with?
I also have a question. I have these same speakers which are 15 ohm and use them on my theater. I am driving them with a Yamaha rxv367 surround AV system. I bought that to replace an old period Nakamichi which went south. Well, I've been using it for about a year and the sound quality is deteriorating markedly. It now requires I take them to really high output to get loud sound and even so, the speakers sound like there is less volume from one than the other. It almost sounds out of phase or something...

I have changed the wires around (rotating the tires as it were) and that is of no effect.

Anyone with insight on gradual diminution of sound output and quality with these? There is no damage to the speakers b/c I can get transient and fleeting great sound from either. I really feel the speakers are affecting the circuitry in some way I don't understand.
I also owned these speakers and had them in my office driven by NAD 3020, fun, and the midrange was excellent. Mostly played Jazz, small scale classical and folk. Fond memories.
Disregard my prior inquiry, I had wired the speakers wrong after moving stuff around and fixed the issue.
LS3/5a had greater continuous longevity in my systems than any other speaker so far. I ran a double LS3/5a system for over a decade (think a miniature version of TAS' double Advent system from the mid-70s) and later used them in in secondary systems of as alternate speakers in my main system, from 1976 to 2002. The 15 ohms load will make most solid state amplifiers sound smoother and more refined, albeit at roughly half their 8 ohms power (unless its a McIntosh autoformer output SS amp). And if the mismatch is with a tube amp with only 8 ohm taps, no harm will occur. The speaker is a great match for OTL tube amps, like Atmasphere or Transendent, today. I used my double LS3/5as for several years wired in series for 30 ohms driven by Futterman OTL monoblocks. Sensational.

The BBC monitor emulated the midrange beauty, tone and human voice realism of the original Quad electrostatic, in a dynamic speaker. It's inefficient and has limited power handline. You generally need 25w to wake them up, and getting much beyond 70w is risky unless you're careful to restrict volume below where you hear the B110 driver driven past its range on bass transients. The speaker was designed before the CD, so dynamic range in digital source bass can put the 4" driver past its limits. The speaker has a bass hump between roughly 80 - 100Hz, to give the listener an illusion of bass range that's greater than the speaker actually has, but it worked well as a tactic for making a very small speaker satisfying. Actual lower limit bass response trails off rapidly below 70 Hz. With the right amplication, LS3/5a can still produce beautiful sound, within its dynamic limits, 40 years after its original development for BBC field monitoring.

Phil
hi i am new and first time on the forum, reason was i just bought a roger ls 3/5a and want to research a bit whether i really got the real stuff or a copy as i have no intention of opening the box as i am in experience and might destroy them!
Why do I never read any posts describing LS3/5a's as parts of high quality automotive audio systems? LS3/5a's are the best car audio speakers I have ever heard. Using FLAC files for the source I drive them with JLAudio HD900/5 amps, JL Audio subwoofer, and additional pair of Focal 5-1/4" front door speakers. I have these setups in a Corvette and a Ford F150. The LS3/5a's can be set on the sides of the F150 back seat  and at the extreme rear of the Corvette hatchback. It is scary how good these mobile systems sound. 
 
On the home front, I also use double LS3/5a's wired in series for 30 ohm load driven by Cary 805C's from the 16 ohm taps. Like the 2012 comment from above, sensational. Using SVS dual subwoofers and an Audio Note Kits Mentor preamp and a PS Audio DirectStream DAC  completes this simple setup. With a quality source as the input, the LS3/5a has an overall sound that I have never heard from any other speaker. It is has an allure that has caught the ears of thousands upon thousands. The sound difference is as pronounced as comparing solid state with tubes. I had a friend recently describe the sound as very lush and detailed without being analytical - Musical. 

Best regards,
Mack



The OP says the Rogers speakers he found were built in 1079. One assumes they are early prototypes.

For information, see http://www.ls35a.com/
The early 15 Ohm models are more popular with collectors and fetch higher prices, even if the later 11 Ohm version is the better speaker. At the time I thought it was the best small speaker on the market, and it is still enjoyable to listen to. Few early models will stil meet the orginal specification (speakers do age). Modern copies have little in common with the real LS3/5a, since the drive units have not been produced for ages.
The modern Hartbeth P3ESR is a distant descendant, and in my view the best iteration of the idea, and far better than the orginal (I have both).
My response is not to recommend an amplifier. You have received a number of good ideas. I want to reinforce not exceeding the 50W maximum power handling. I auditioned the Rogers in 1977 finding the sound wonderful! The seller, an audio engineer, did caution not exceeding 50 watts.Too bad I did not buy a pair then. Enjoy!