Which to keep! Pick one of these two soeakers

To me the MLs are a no brainer. Great mids and highs and the hybrid design sounds great.  New panels.  slam dunk.

If I had your stuff and perceived problems my inclination would be to get a decent quality equalizer, like the Schiit Lokius, a six band equalizer with 2 bass frequencies, and supplement the output of the pre-amp i.e. between the pre and the amp. Costs about $300. 

BTW, are you sure that your listening position is not in a bass frequency null? If so simply moving your chair a bit could solve your bass problem. 

FWIW IMHO bi-wiring is more of a perceived benefit than a real one. I suppose with SOTA stuff and critical hearing skills the difference might be apparent, but note a lot of manufacturers have not provided for bi wiring. Some very high level stuff. The only difference when bi wiring that I could hear was when I used different cables, i.e. ones with a different set of sonic values.

@newbee Both amps sound good, the ARC sounds maybe a little smoother like you said, a little more organic while the Musical concepts is a little cleaner and in your face. Both sound really good though. One thing to consider though is that both sets of these speakers are having issues with low end when bi-wired. Each sounds much better when you push more low end to the subs. The upper registers sound much better on the Spendors, much more texture and guitars/horns sound incredible and detailed/alive. The ML are a little more piano like in the upper registers, seems like a little air is missing that is in the Spendors. I might try running the amps bi-amped, if there is a natural volume difference between the two amps maybe I can use that on the bass side to push a little more low through the speakers.

Just for fun, humoring me perhaps, just try running the speakers full range with one amp. First the Musical Concepts then the ARC. Listen to the 'sound' and the differences you get with these amps. I suspect that tonally speaking there might not be a huge difference, but I think that the ARC will have a smoother sound than the SS amp. I don't know what your 'rack' looks like but you can deal with the ARC's heat by either putting it on the top of the rack or placing it on the floor next to it. For sure make sure you give the amp a lot of free space around it. 

Sell that Mac and the 555. Neither, in my estimation, has the 'quality' potential of the Musical Concepts and ARC. 

@newbee  honestly, I had high hopes for the ARC VT100 but I'm a little put off by the extra heat it puts off around my wood Rigidrack. Kind of makes me nervous but maybe not an issue. Right now I have a McIntosh 4100 + Adcom 555 hooked up and the ARC is out of the rack momentarily. I have the MAC hooked up to the panels and the Adcom on the woofer. When I crank up the preamp to about 70% I can blend in the desired amount of upper register on the Mac and I also have the EQ on the MAC. I have to say it is very useful but I wonder if I just downgraded by pulling the ARC out of the rack. I had initially planned on selling the MAC 4100 to recoop some of the money I spent on this system's various components. I can get $1500-2000 for it on eBay.

You need a passive attenuator of some kind between your pre-amp and one of the amps, probably the amp feeding the sub. I see them coming up for sale used between $400 and $600, but from my point of view I think what you might gain by bi amping these speakers you’d lose by all the extra stuff it takes to do it. I’d run them off one amp. FWIW, the Musical Concepts mod changes my opinion of the Adcom, but I’m not convinced that it is a better amp for the panels. My gut tells me the ARC amp should go to the panels and the Adcom to the subs. When you figure out how you will get the two amps balanced, output wise, try switching them around.

@newbee so it turns out that the Adcom is actually a totally rebuilt dual mono Musical Concepts creation. I found the docs and receipt for the work and sure enough the device is gutted with some amazing work inside. So the guy was powering the panels with this solid state creation and the subs with the VT100 MKIII tube amp. I could hook it up the same but I'm now missing a way to balance the signals. I need a way to control how much signal goes to the Adcom vs the amp for the subs. 

@cabkab Hey, at least I like your response!

For myself, I’ve had for over 20 years now, 3 pairs of speakers that I switch between every ~6 months. They each sound VERY different from each other, and I appreciate the qualities of each, and acknowledge their shortcomings. Luckily, I am ABLE to keep, and store all of them, and have a wife that doesn’t mind big speakers!

They are B&W Matrix 801’s, Martin Logan SL3’s, and Tannoy System 15’s. Each are very different designs & directivity patterns. The 801’s have wide dispersion dome tweeter, Tannoys have 90deg horn tweeter, and Logans are Fig-8 E.S. panels. Each pair also makes me favor the music that sounds best on them.

My recommedation to any audio/music lover is (if you can) keep 2 very different sounding pairs of speakers to enjoy. 

Ok @mirolab Didn't mean to upset you, buddy.             

@kennymacc @mirolab The experience of others with the same speakers is just a factor in my decision. A wise person is open to the experience of others. A fool makes decisions in a vacuum. There may be people who have had each of these for decades, they will know things that I will not know in a only the weeks I’ve had each of these. Space restrictions for forces me to choose one pair quickly.

Get rid of that Spendor (generic crap, nothing special about it) and keep the MLs. The MLs are a bit too unique/not replaceable.

There are many speakers that can easily best that Spendor in 2023. If you miss the spendor one day, get a Mofi Sourcepoint 10 (which beats the living snot out of that Spendor and you will no longer miss it) or a JBL HDi-3800.

One of them is concentric driver done right and the other is a compression driver/waveguide/horn done right. You will thereby end up with a ML and one of these, i.e., 2 very different designs that do very different things well.

It’s true. You really shouldn’t ask others what speakers you should keep. As with all things high end audio, and especially with speakers, it’s strictly a personal choice as to what's most pleasing to your own ears. You must simply listen, listen, listen, and keep listening until you figure it out on your own.  No matter how much time and patience is required, it's the only way.

I have a chicken and a fish.  Which one should I kill for dinner?

@cabkab perhaps you can post a photo of your spendors--according to the reviews i read the s100 model was made from 1989-1994 (there was an sp100 model thereafter. in any case, i've heard it and it's vg--i'd try tinkering with the levels on your sub before i hacked into the crossovers on the spendors.

@loomisjohnson my spendors are below 1000 serial number and are probably pretty old. I'm not sure how many they made in the 70s/80s but it would not suprise me if they are pre-1990. I wonder if I rebuild the crossovers if they might sound a lot better on the lower register. It's possible that the crossovers are out of spec and not pushing enough low frequency down to the subs.

Whatever you do, keep the S100s because you won't realize just how good they were until they're gone. Many of us would give a limb for those. MLs might impress short term but will simply fall short in the overall musical satisfaction category. Btw, these are a speaker that both sound great and measure just as well. But if you sell them, I'll buy them!

i think the spendor s100 are of 1990 vintage, so not so old. since you have a sub i'd pick them over the martin logan, which look cool but didn't sound that great to me.

Your opinions are super helpful, there are little bits of information mixed in to each that helps me piece together some of the greater experience you all have with these types of speakers. To those who are a little rubbed by me asking for the experience and opinion of others, I find it extremely helpful, and it helps me to bring attention to things I may not have otherwise consciously been able to consider in my decision. It also adds confirmation to the experience I've had, or helps me reconsider things that maybe I got wrong. There have been many useful points brought up here. 

I mainly bought this guys system for the VPI turntable, Audio Research pre-amp, CD Player and VT100 MKIII power amp. Those three items are nicer than the core of my #2 listening room that is also my home studio. There was a whole bunch of other stuff in the rig like a transient noise reducer, the Adcom amp, the speakers. I was initially thinking I'd sell the speakers but they turned out to be pretty nice which is what got me into the predicament of considering my Spendors for replacement. I wonder if I could fit both sets of speakers and wire them to an AB switch. They are different Ohms though, The ML are 4 ohms and the Spendors 8 ohms. I wonder if there is a way to wire them up to a couple of switches and turn off one, turning the other on. 

There was a Marchmand EQ and a Marchmand tube crossover also hooked up to this system that got sold out from under me. I would have really liked to have those to play with on this setup. That may have helped a lot with the Martin Logans. I feel they need a little high rolled off at times from what I'm hearing, maybe the lows bumped just a tad. Same with my Spendors, they are really bright but I really like the clarity 99.9% of the time. I have a sub that I use to fatten the room up. 

Is there a good EQ that I could invest in that ya'll would recommend? I really liked the Marchmand controls, it was 5 knobs and pretty simple and seemed well built.

I agree with those suggesting optimization can be a big factor  You've had one for decades and they tend not to be too particular on set up  ESL's typically a different story   I would guess the Martin Logans have greater potential for realism, accuracy, esp for seated listening in the sweet spot  

@barts 

😊 do as I say, not as I do.

Why did you buy this "other" system in the first place?  I'm guessing it was for one of the pieces of electronics?  

So now presumably you have two complete systems.  If it were me I'd keep the best of the electronics and sell both pairs of speakers.  Even then that might bring you ~$3k.  Add $2k to that and go find a new speaker that you really like.

Having said that just keep them both...life's too short for such pondering.

BTW, I'm the worst at selling things (anything), I still have my first car, my first motorcycle, my first house, my first wife.  I also have three sets of amps (ARC, Pass, Hafler) to run three complete tri-amped systems.  Eleven amps in all.

Probably healthier to simply ignore my post.

Regards,

barts

New speakers, new equipment, bi-amp, only 1 sub with Spendors, what a circle of confusion.

1. change only 1 thing at a time.

Listen to your most involving music on your existing system.

2. Change speakers only. More or less involving?

Speaker choice is done, keep the other pair in the garage for a few months while you mess about with various combinations of existing/new equipment. Settled, then compare the speakers again, ... more involving?

................................................

now, move on to other changes, 1 at a time.

...............................

I agree, a matching Pair of Subs would definitely be a step up

not just in amount of low end, but enhanced Stereo Bass. Every note has fundamentals, and they progressively become more directional than a bass fundamental: front firing, no ports, located near primary speakers as a Stereo Pair.

Bass Imaging: Where’s Wally? Where’s Ray Brown standing?

@bigtwin

Ditto!

Keep one of each 🤔

Spendor S100 in a landslide great classic speakers.

I have two glasses of Red Wine in front of me.  Can someone tell me which one I prefer the taste of?  Sorry, but if you have two sets of speakers in your room, and you can't tell which one you prefer, I don't understand how the opinions of others are going to help?  If you really can't pick one based on your own listening experience, then I would say sell the one that will bring the most money.  

Just my 2 cents.. if financially viable keep both. You have two very different designs , with different strengths and weaknesses. Keep them in your main listening space, swap them, mix and match to musical performance strengths. Disclaimer : I own way too many full range speakers because of this approach. 
 

If you only have the space for 1 keep the Spendors.  They are a bit more versatile, and should sound better on most songs.  However with the right song, panels can do magic no box speaker will match. I'd do my best to keep both since they are very different speakers.  I've got a box/horn (Dynaudio/Klipsch) pairing myself.  One in the bedroom and the other in the living room. 

The sonics you are describing have a lot to do with your equipment.

Happy Listening.

How many hours do the "new" panels have on them.  They need about 200 hours to break-in.

I'm a panel guy and biased, so I say keep the Martin Logans...

IMO you should be able to pick your own speakers? 

I guess I don't understand what you are asking? You own both pair now, yes?

You can configure them how you like, yes? You can listen to both and decide which pair sounds best? no???

I'm all for using one amp for both panels and subs. I've a hard time thinking the Adcom would be a good match (soundwise) for the panels. When you set these up, I assume in a somewhat triangular configuration, you need not be as concerned with sidewall reflections (as you would with boxes, but the rear wave is a potential problem. To hear this speaker best it should be about 6 ft off the wall behind it. Dispersive material on the wall wouldn't hurt much either. Good place to start anyway. Take your time with setting up these speakers before you come to any final conclusion. 

The previous owner of the Martin Logans had them bi-amped with an Audio Research VT100 (feeding the subs) and ADCOM GFA-555 (feeding the panels). The Audio Research SP16 preamp feeds both amps. I have all of this gear now but I’m only running the VT100 biwired to both the panels and subs in parallel. The room is carpeted and about 12x20 or so. I’ve beed auditioning the Spendor and ML with the Audio Research pre and tube power amp.

While ultimately it depends on how they sound to you. However, it also depends on your electronics and how much time you have spent with the Martin Logan. 
 

It would be really helpful to know your components and venue… there is a place under your UserID to create your virtual system. It is easy to attach photos and ID equipment there. This would help us better determine how to help.

Just in general, I suspect the Martin Logan’s are more challenging to power and position and perhaps you are not getting the optimal sound from them. They can sound very good.

Sound wise, your choice, you've go both on hand. Panels and boxes sound very different. I've had panels, electrostatics, and boxes. Set up for panels can be a journey, boxes are relatively simple. Ditto amplification. Those old spendors are a fine speaker. Panels can (can, not will automatically) sound more dimensional if properly set up. 

Sounds like in your heart of hearts you prefer the Spendors.  If that’s the case I’d sell the Ascents and add a second sub that’ll likely provide a very nice improvement with your S100s.  FWIW, and best of luck.