Synthesis LM-260 question

[jobob42]

Hello. all. I recently took possession of a pair of LM-260 speakers. I've been using a kit speaker from Madisound, Loki speakers, designed by Seas to feature their one of their coax drivers. Even though these are crisp neutral and honest, and I use a Hsu subwoofer with them, I wanted a fuller sound from the mains. After a long search and think I found these LM-260s, added a decent crossover and hooked them up.
All seemed very good until I compared them directly to the Lokis. The smaller speaker had more clarity, punch on percussion. This did not seem right.
I looked at the bottom of the 260s and noticed that around the speaker post plate, which would have the crossovers on their inside surface, is a bead of silicone sealant.Why would this be? I tried to contact the seller, but no reply. I suspect that he, or someone, tried to mess with the crossovers, but I can't confirm.
So, my question: Is it likely that my $500 Seas Loki speakers could sound better than my lovely new/old LM-260s unless somebody messed with the innards? Is there any way to really upgrade these crossovers, or at least return them to spec?
I will do more comparisons between the speakers, but this IS a vexing thing.

Thanks, and glad to be here.

Sonographe SG3 turntable, decent Grado cartridge, PV5 Pre-amp, Assemblage (Sonic Frontiers) ST40 tube amp, miniDSP Digital Signal Processor for crossover between main and sub speakers, Hsu Research powered sub.

[admin]

First, welcome to the site. Great to have you with us.

As for the LM-260. I think there are two things to contend with. The fact that somebody may have altered/upgraded/fixed/messed with the speaker over time. This is clearly going to change the sound. The silicone I'm not sure of what is going on, but I've seen speaker manufacturers use silicone to simply keep components in place. It's a safe non-conductive material.

The other issue is that that the LM-260 is very old. I've had very old speakers (+20-30 year) have their woofers deteriorate over time. This can cause aberrations in the sound.

As to bringing the crossover components up to spec, I think you would pretty much have to replace any caps and resistors.

I also own a Hsu sub (which I use in my home theater setup). It's the VTF-15H. It's a beast and great bang for your buck.

[AnotherJohnson]

I would echo admin’s caution about old speakers.

Cone materials, crossover components, and even stat panels change as they age. It seems to be unimodal. Stuff sounds off when it’s unpacked. A few hundred hours later it sounds grand. And then 10+ years later, it is slowly going down hill. Often so slowly that the owner gets used to it as it goes and perceives nothing negative. Then, one day there is an opportunity to make a comparison with something in its prime, and if one’s ears still work well, the degradation becomes obvious.

That doesn’t mean it’s not fun to put together a vintage system, including period correct speakers.