Spendor LS3/5A

Hi All,

I'm very seriously considering purchasing a pair locally, but am not completely familiar with all the iterations and permutations of these famous speakers.

I'm attaching some photos from the original listing (which the seller, very nice guy, has taken down until I come and listen)

How do I know if these are the 15 ohm versions or the 11? The seller said that he measured resistance at the speaker terminals and got 7.5 ohms - does that indicate that these are the 11 ohm versions? I see some threads indicating that these serial numbers should indicate older 15 ohm versions

Anything I should pay particular attention to in checking these outs - faults specific to these I should be aware of?

lastly I'm thinking of driving these with a Conrad Johnson MV75a - 6550 based tube amp - does that combination seem to be a good one? The seller felt that his Fisher 400 didn't have quite enough power for these

thanks
 

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resistance measured at the speaker terminals with a multimeter will be a measurement of DC resistance of the voice coil.
this is different from nominal impedance which is what the '15 ohm' version is referring to

you can remove the rear cover and inspect the crossover to know for sure. I can date Rogers units but not spendors
 
resistance measured at the speaker terminals with a multimeter will be a measurement of DC resistance of the voice coil.
this is different from nominal impedance which is what the '15 ohm' version is referring to

you can remove the rear cover and inspect the crossover to know for sure. I can date Rogers units but not spendors
Can you find out using the serial number?
 
Hi All,

I'm very seriously considering purchasing a pair locally, but am not completely familiar with all the iterations and permutations of these famous speakers.

I'm attaching some photos from the original listing (which the seller, very nice guy, has taken down until I come and listen)

How do I know if these are the 15 ohm versions or the 11? The seller said that he measured resistance at the speaker terminals and got 7.5 ohms - does that indicate that these are the 11 ohm versions? I see some threads indicating that these serial numbers should indicate older 15 ohm versions

Anything I should pay particular attention to in checking these outs - faults specific to these I should be aware of?

lastly I'm thinking of driving these with a Conrad Johnson MV75a - 6550 based tube amp - does that combination seem to be a good one? The seller felt that his Fisher 400 didn't have quite enough power for these

thanks

The Spendor LS3/5A I owned were from the early 90s. They were 11 ohms and bi-wire able. So ask the seller for that detail.

Even if they're rated @ 82.5dB/1W/1M, they present a benign high(ish) impedance = easy load. IME/MHO, they sound best driven by a PP ultra-linear EL84/6BQ5 like a Dyna ST35 or triode connected EL34 along the lines of an Eico HF87 or ST70. When I drove them (I also had 15 ohm Rogers from the early 80s) with a Citation II or even a stock (UL connected) ST70 or 8B, I lost dynamics and detail. The compression could be due to the greater amount of negative feedback from higher powered amps(?). They're only rated at 25W max and were designed for near-field monitoring. Funny that the seller didn't think the Fisher 400 (7868s) didn't have enough power for it because I really loved that combination, so YMMV.:)

FWIW, I revisited a pair of LS3/5As a couple of months ago.
 
I was surprised to hear that he thought the 400 wasn't enough for the spendors as well, but in talking to him it might just be that he's using them in a large room and is expecting a higher volume level than the are supposed to put out.

I would be using in a bedroom setup, so that would not be an issue for me
 
Hi all, I did some more research and asked around in LS3/5a specific groups, so I am going to answer my own question, in case anyone in the future comes looking for this info

these are 15 ohm versions, identifiable by 3 factors: serial number under 7000, gold badges, and "white bellies"; i.e. the white ring around the dustcap which is a residue specific to the KEF woofer on the 15 ohm models.

and they are shockingly good for their size, I think I may need to try them with a little subwoofer though and also may try different amps
 

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Hi all, I did some more research and asked around in LS3/5a specific groups, so I am going to answer my own question, in case anyone in the future comes looking for this info

these are 15 ohm versions, identifiable by 3 factors: serial number under 7000, gold badges, and "white bellies"; i.e. the white ring around the dustcap which is a residue specific to the KEF woofer on the 15 ohm models.

and they are shockingly good for their size, I think I may need to try them with a little subwoofer though and also may try different amps
I have the 15 ohm Rogers LS3/5a.

Using a subwoofer is a bit tricky with the LS3/5a. There is quite a "hump" in the bass. Satterberg(sp?) Used to make a dedicated 12" woofer for the LS3/5a with a passive 180hz high-pass filter at 18db/octave and a 12db/octave low pass filter for the woofer.

Ultimately, I prefer my LS3/5a "as-is" on 26" - 30" very solid stands and placed well out in the room. They are sweet speakers! :)
 
I have the 15 ohm Rogers LS3/5a.

Using a subwoofer is a bit tricky with the LS3/5a. There is quite a "hump" in the bass. Satterberg(sp?) Used to make a dedicated 12" woofer for the LS3/5a with a passive 180hz high-pass filter at 18db/octave and a 12db/octave low pass filter for the woofer.

Ultimately, I prefer my LS3/5a "as-is" on 26" - 30" very solid stands and placed well out in the room. They are sweet speakers! :)
Something like a Rel is said to work best when you run it off the speaker outs, in between the speakers and amp. Using its high/low pass cutting off what goes to the speakers below say 100hz or whatever.
 
Something like a Rel is said to work best when you run it off the speaker outs, in between the speakers and amp. Using its high/low pass cutting off what goes to the speakers below say 100hz or whatever.
This is the plan (though using an m&k)
 
Something like a Rel is said to work best when you run it off the speaker outs, in between the speakers and amp. Using its high/low pass cutting off what goes to the speakers below say 100hz or whatever.

This is the plan (though using an m&k)
Just conveying what I found when trying to use a sub with my Rogers LS3/5a. There is a hump (under damped with a Q of ~2.0 IIRC) in the 150hz range before a steep roll off starting at 100hz - this is the famous "BBC Hump".
R35FIG4.jpg
When I tried to bring a sub in at 100hz, the bass got muddy and ill defined. Unfortunately, it also clouded the upper bass that the Ls3/5a was rendering.

After trying several subs and woofers (including the Satterbergs, which cross at 180hz and were made to mate up to the LS3/5a), I found that the LS3/5a provided me with a much more involving and musical experience when used without a sub.

As always, YMMV. :)
 
Just conveying what I found when trying to use a sub with my Rogers LS3/5a. There is a hump (under damped with a Q of ~2.0 IIRC) in the 150hz range before a steep roll off starting at 100hz - this is the famous "BBC Hump".
View attachment 41924
When I tried to bring a sub in at 100hz, the bass got muddy and ill defined. Unfortunately, it also clouded the upper bass that the Ls3/5a was rendering.

After trying several subs and woofers (including the Satterbergs, which cross at 180hz and were made to mate up to the LS3/5a), I found that the LS3/5a provided me with a much more involving and musical experience when used without a sub.

As always, YMMV. :)
Yikes. Yeah I better understand the issue with that. I had that problem with the gradient subs and crossover on my quads. They gave a little more bass but killed the magic.
 
I have a pair of RAM LS3/5As and a pair of the Satterberg woofers. (I had a pair of Chartwells in the 80s but foolishly sold them to buy something else, always something else.) I enjoy the combination, and find that the high pass cutoff above the BBC hump was an excellent idea, and therefore stereo woofers are needed.
 
the high pass cutoff above the BBC hump was an excellent idea, and therefore stereo woofers are needed.
Yes, thank you for pointing that out. I neglected to include that info. Stereo woofers are required due to the higher crossover point. 👍
 
Yikes. Yeah I better understand the issue with that. I had that problem with the gradient subs and crossover on my quads. They gave a little more bass but killed the magic.
Quads (especially the ESL57) and the older 15 ohm LS3/5a are so good at what they do well that, in my opinion, adding stuff on to make them a more complete speaker ends up interfering with what makes listening to them such a magical experience. :cool:
 
But some of us do like bass….
I'm with @TubeHiFiNut on this one. If bass is your thing then don't try to make something not made for bass, try to make bass. My ESL-63s fell on their face anytime I tried to make them into something they weren't. That's why God made other speakers, many with bass :)

I don't quite get the LS 3/5a thing but I totally get the notion of things performing best when they're asked to do what they were designed for and not asked to be something they were never intended to be. I guess with that you should listen to your LS-3/5as in a mobile mixing van outside a live news broadcast but... anyway....
 
I'm with @TubeHiFiNut on this one. If bass is your thing then don't try to make something not made for bass, try to make bass. My ESL-63s fell on their face anytime I tried to make them into something they weren't. That's why God made other speakers, many with bass :)

I don't quite get the LS 3/5a thing but I totally get the notion of things performing best when they're asked to do what they were designed for and not asked to be something they were never intended to be. I guess with that you should listen to your LS-3/5as in a mobile mixing van outside a live news broadcast but... anyway....
I think you misunderstood what I was saying. Likely because I didn’t make it clear. :)

I can’t imagine listening at length to a speaker that doesn’t do really any bass, and what it does do, it cheats on horribly. I would love using them as mobile monitors for my recording work, if I ever decide to do any, but they just give away so much musical information, that I’ve never been able to think of them for my own system. Plus, they force me to pick music that suits them.

That all being said, they do wonderful things in the midrange.
 
I think you misunderstood what I was saying. Likely because I didn’t make it clear. :)

I can’t imagine listening at length to a speaker that doesn’t do really any bass, and what it does do, it cheats on horribly. I would love using them as mobile monitors for my recording work, if I ever decide to do any, but they just give away so much musical information, that I’ve never been able to think of them for my own system. Plus, they force me to pick music that suits them.

That all being said, they do wonderful things in the midrange.
And my long winded response was basically "eh, just get a pair of speakers that does bass as well as midrange if that's what you're after".
 
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