[Ultralight]

Greetings,

I've posted a few times in this forum and have always received kind and excellent insight.  Very much appreciated as I still consider myself very much a newbie.

Currently running a Line Magnetic 845 SET tube amp powering a KEF LS50 with the LM502 DAC as source.  We picked the LS 50 after we auditioned a number of speakers under $2500 side by side. (Martin Logan, Totem, Golden Ear etc)  In the end, the LS50 was clearly the most natural with the most resolution and coherence.  Listening to acoustic music primarily (from vocals to orchestra), the resolution of the LS50 simply sounded the most realistic.   Other speakers sounded more impressive initially such as having a larger scale, more bass extension, or even being more holographic.  But within a few minutes, we realized that pianos, violins etc all sounded most like the actual instruments with the LS50.  A friend explained that this is due to the timbre and resolution.   Our listening room is not large at about 11 x 13 feet or so and two doors behind the listening position that extend to larger areas beyond.

Our test were with a solid state amp.  I've since switched to the 845 tube amp and love the improvement in sound quality.

However, after about a year and training our ears, realize that there are some things that we want more of that he LS50 cannot provide including more warmth, bass presence, scale, and especially the ability to come alive at very low volumes of 55-60 db from 6 feet distance.  The LS50 comes alive at about 75db mark and we don't really want for much.

So on this hunt for new speakers that will still give us the resolution, spatial focus (if that's a term) etc of the LS50 but have the ability to communicate musically at low volume at a larger scale, with more warmth etc.  This is not a case of low volume response in my ears.  Using good mid grade headphones shows that i'm OK with low db music as long as the speaker or headphone does not loose its dynamic naure.

Since my amp is a 22 watt SET, are there specific characteristics of speakers that I need to look for?   For example, is there a general rule of thumb as to efficiency that is ideal?  Some have suggested trying full range speakers though I've not yet done that in part from lack of places to hear them.

I've been looking a number of smaller small shops such as Fritz and Ascend Sierra as they are practically in my backyard.  Also looked at Vapor.  But most of these are around 89db efficiency.

I would very much appreciate and welcome any insight.

Thanks!
UL

[franktfreo]

Greetinings - l have just registered and starting my tube journey after many years of solid state sound. I am 63 and live in Perth Western Australia.

I have recently bought a very basic tube amp and looking to add perhaps through this forum/trading post.

Looking at some speakersin the trading section but can't send messages.

Kind regards to all

[shooter]

Try a pair of well maintained or refurbished Quad 57, very few speakers  can match them in naturalness and resolution.

[DavidS]

I have the same size listening room - very tough to get the speakers right.  I also run a low watt amp - in my case Consonance 300b monos.  Have been through many speakers - Zu Druids, Frugelhorns, Ellis 1801s, little Harbeths, big Audio Note HE's, I'm probably forgetting a few.  Sadly no Quad 57's - have still not heard them. 

My current speakers are the best I have found for the room - Merlin TSM's.  For me a case of just right.  The Harbeths were probably like your LS50's, nice detail, good top end but just not enough at lower end and with full scale music.  Tried them with a sub but just too much boom.  The Ellis 1801's are the best I have found prior but honestly don't match up to the TSMs even with an upgraded crossover that I did.

Now what I would love to try - maybe an open baffle, definately an omni like Ohm or German Physicks, also a high quality full ranger, have even been thinking about a smallish maggie (quads again) - also have nice McCormack amp that I could use.

Small room audio, so many people doing it but it seems most discussion is about big listening rooms.

[rollypolly]

Looking at Stereophile's measurements for the LS50, it does not look like a good candidate for SET amps, even an 845.

The impedance and phase angle graph (fig. 1) show a wild ride that's hard for most SET amps to keep up with, especially between 80 to 230hz where most of the mid bass can be found. In this region, the impedance drops down to 4 ohms with the phase angle at -45 degrees: OUCH! The LS50's are demanding the amp supply lots of current and tube amps, especially SETs, are not the right candidates for this type of job.

For more info in choosing the right speaker for your SET amp, check out this link that gives a full explanation of what I'm talking about.

Cheers!
Rolly

[FullRangeMan]

Seems the KEF LS50 are only 85dB sensitivity, which is not suited to a 20W amp even solid state.
LS50 would work well with a monster 100W tube amp.

For this refined 845 I would try the Zu Soul(99dB and 8 ohms) or a paper cone + Alnico fullrange.

[rollypolly]

Low speaker sensitivity doesn't necessarily mean that it is SET unfriendly  . A good example is the Rogers LS3/5A at 82 db/W. How so? Well, the impedance curves are well above 8 ohms for the most part and a phase angle that drops down only once to -45 (though impedance is well above 20 ohms at that point). This makes the LS3/5a a very SET friendly amp.

However, it won't play loud but then again it's not like the LS3/5a has a lot of dynamic headroom  .


Cheers!
Rolly

[rodge827]

UL,

There are many speakers that can sound very good on 22w SET amp.
Could you please give us the parameters you are working with.
Budget?
Listening preferences?
Monitors?
Towers?
Add a sub or two?
Associated gear?

I have a very good 2.2 set up and have been considering the amp you have when the funds become available.

Chris
   

[Quiet Earth]

I think it is difficult to get a full and lively sound at 55-60dB SPL listening levels regardless of amplifier or speaker choice. Most recordings are mastered closer to 85dB peak SPL and that will have a significant influence on when the music begins to sound full and alive.

I think you can find a speaker that becomes more alive at those very low levels, but you will always notice that they open up somewhere in the middle to upper 70s, just as you have already demonstrated to yourself. This has been my experience as well, and I feel like my SET amp and speakers excell at low volume listening.

Maybe what you should look for is a speaker that doesn't sound like it is playing very loud at all, even though it is peaking close to 80dB. What do you think of that idea?

Also, I agree on the budget comment. Without a budget it is hard to recommend anything.

[Quiet Earth]

I took a quick look at your KEFs just to get a visual idea of what you have. How close to the rear wall are they placed in your room? The reason why I ask is because if your primary goal is low listening levels, then any room boundary reinforcement will be helpful in achieving that goal. Since your speakers have rear ports, you can take advantage of moving them closer to the wall behind them to get some more fullness at low volume. Then you can adjust the toe in to recapture imaging.

(You probably already tried that .......    )

[FullRangeMan]

Low speaker sensitivity doesn't necessarily mean that it is SET unfriendly  . A good example is the Rogers LS3/5A at 82 db/W. How so? Well, the impedance curves are well above 8 ohms for the most part and a phase angle that drops down only once to -45 (though impedance is well above 20 ohms at that point). This makes the LS3/5a a very SET friendly amp.

However, it won't play loud but then again it's not like the LS3/5a has a lot of dynamic headroom  .


Cheers!
Rolly

LS3A was created to BBC monitor(where low sensitivity is acceptable since there is a huge solidstate amp driving it) and to please the English taste, dark, dull, no bass and anemic treble.
Decidedly this speaker will shorten the life of the output tube due the low sensitivity.

[mick wolfe]

I have an even smaller room to deal with, but I have no trouble adjusting a single REL T-2 sub to integrate with my main speakers. As already suggested, 2 quality powered subs would get you very close to what you're trying to achieve. I also use a Line Magnetic 845 based amp. ( 218IA)
Main speakers are either Ohm 1000's or Soundfield Monitor 1's. The Soundfields are based on a similar KEF driver. The huge difference here is that they have a separately powered woofer in the same cabinet. Neither of these speakers is particularly efficient, but their impedance is fairly benign. In my experience, an 845 based amp such as the 218IA sounds as strong as a typical 50-60 watt P-P tube amp. Double that power rating for solid state if you want to achieve the same sense of ease. If you do want to look at further speaker options and have an open mind, consider the Spatial Hologram open baffles which are 100 db efficient. The smaller model 2 will be the next speaker I plan to audition.

[fritzspeakers]

Hi UL-  I just read this post regarding your 845 tube amp.  I've built loudspeakers since 1973, (Yikes! 40 years, has it really been that long?) and wanted to let you know that any of my speakers will work fine with your amp.  I've done many trade shows in the last couple of years using a great Electra-Fidelity 300B tube amp @ 10 watts per channel & I also have a customer with ASL 845 monos with my Carbon 7's.

I like to use paper mid/bass drivers & fabric dome tweeters that have smooth roll offs & don't need a ton of crossover parts that suck up power & good sound.  My loudspeakers with 1st order series crossovers are super easy to drive, look at the impedance & phase curves of my models.  (You will never see smooth graphs like these unless they also use series crossovers!)

Let me know if you are interested in a home demo.  Thanks, Fritz

[Freo-1]

Hi UL-  I just read this post regarding your 845 tube amp.  I've built loudspeakers since 1973, (Yikes! 40 years, has it really been that long?) and wanted to let you know that any of my speakers will work fine with your amp.  I've done many trade shows in the last couple of years using a great Electra-Fidelity 300B tube amp @ 10 watts per channel & I also have a customer with ASL 845 monos with my Carbon 7's.

I like to use paper mid/bass drivers & fabric dome tweeters that have smooth roll offs & don't need a ton of crossover parts that suck up power & good sound.  My loudspeakers with 1st order series crossovers are super easy to drive, look at the impedance & phase curves of my models.  (You will never see smooth graphs like these unless they also use series crossovers!)

Let me know if you are interested in a home demo.  Thanks, Fritz

Hi Fritz,


Your speakers have piqued my interest.  Could you explain how you are able to get a smooth response and still maintain a efficient design?   I would like to obtain a lower powered tube amp that would match up, but so far, no luck on the speaker end.  My current speakers(which I really like) are 85 db/W, and can get up to 108 db max without breakup (not that I would listen that loud  ) 


They need a good 80 watts of tube power, or 120 watts of SS power to open up, which limits amp choices. 

[DaveC113]

For low-level listening, acoustic music and small room it'll be hard to beat the Omega Alnico XRS, it's a good match for a SET amp too.

[Quiet Earth]

Here come the salesmen again . . . .

I guess you figured it out because now your amps are for sale. Hope everything goes well for you.
 

[kgturner]

Not to jump off topic, but I have a Line Magnetic 518IA and am giving a hard look at the 502CA for my digital source. How do you like the pairing between your LM integrated and the 502CA? I would assume a certain level of synergy between the two, but you never know til you listen. Thanks.

Kevin T

[rollypolly]

Decidedly this speaker will shorten the life of the output tube due the low sensitivity.

Output tube life spans are determined by the tube's operating point (power level dissipation) and the impedance load of the loudspeaker. Nothing to do with speaker sensitivity.

Cheers!
Rolly

[Ultralight]

THANKS to all who replied.

Briefly - we listen to a wide range of music in the acoustic vein from solo vocals to orchestral. Occasional movie music.   But virtually no rock or electronica etc.  We value a very accurate timbre.  Like some sense of warmth/romance, but without sacrificing resolution.  Imaging and depth also valued as well as scale.  The LS50 does not have much sense of scale for us. But it does have gobs of accurate timbre.  This is very obvious with things like grand piano and violins. 

My LS50 are about 20 inches from the wall, about 6 feet apart. Have a couple of subs which are sealed and each has a pair of 8" drivers.  But I've not integrated the subs yet and only one is running - waiting for cables.  I do not think the subs will resolve the issue for us.

Price - that's a bit flexible though we are on a tight budget due to leaving profitable career choice to go into the non-profit sector.   (Love it! Not even remotely regretting it for a second.)

Never heard a full ranger on my 845 SET but curious.  Talking with Zu, and giving my description of what I am looking for including the desire for good resolution, the gentleman said that I would probably have to start with their $4K unit which is definitely beyond our reach.

Fritz, will chat with you more.

As to the 502D, love it.  I have the Oppo 95 which a friend helped me get for a great price. It is not slouch.  But the 502D dac is considerably better - more weight, presence etc and resolution.  I was surprised as I did not think that there is that much gap above the Oppo 95.  Learned something.  Actually have two of the 502.

Hope this helps.  Again, grateful for all the comments.
UL

Not to jump off topic, but I have a Line Magnetic 518IA and am giving a hard look at the 502CA for my digital source. How do you like the pairing between your LM integrated and the 502CA? I would assume a certain level of synergy between the two, but you never know til you listen. Thanks.

Kevin T

[sns10920]

Just registered a few days ago, so entering thread rather late. In my experience I've found that tube amps don't come alive until aprox. somewhere in 80's db reached. I currently run Art Audio Carissa Signature (845 SET) and/or Conrad Johnson MV55 with Merlin VSM-MM (all Duelund caps) and this setup never comes alive until sufficient volume is reached. Merlins are aprox. 90db and have a benign impedence curve (never really going much below 6 ohms impedence) so SET works well this speaker. I formerly ran a few different Alon speakers (some with very easy impedence curves) with a variety of Cary tube amps and they never came alive until a sufficient volume was reached. Same with some single driver speakers with 2A3 based amps.
I haven't looked at the impedence curve of your speakers, but I believe this loudness issue is endemic to tube amplifiers. Over the years I've read in forums others complaining about this very thing. Still, I believe that SET's and especially the 845 tube are a bit more sensitive to this issue, I don't recall hearing to the same degree this sudden transition from uninvolving to a sense of aliveness dependent on volume that I hear with the Art Audio.

Undertow, I did see your LM518 up for sale, rather a coincidence since I was seriously considering purchasing an LM518 over the past few weeks. I wanted to hear another iteration of an 845 tube amp in my system. Based on my research that is one of the few other 845 SET's I would consider adding to my collection.