Synergistic Research XOT Carbon Crossover Transducers

I have them on my Q3s. I had the older model before that. The effect is fairly subtle. More a sort of clearing up of the sound of the speaker and a reduction in perceived hash and noise. Make sure you have room for them, ideally in a combo speaker connection where you can plug the XOTs into the banana socket while connecting your main cables to the spades 

To put things in context treating the cabinets for HFTs had much bigger impact for me. So overall worth trying but do take advantage of the 30 day test offer. 

How much are these ? Is the $450 cover both Loudspeakers ?

Yes, the price is for a pair for two speakers. Each one is terminated with spades or bananas that you connect in parallel with your existing speaker cables

Ok Thank you, what are the HFT ? That made more of a difference ,and how much were these ? Thanks much,Paul.

HFTs are the little concave discs that attach to the walls at reflection points,  they come in sets of five for $295, ideally you use them in conjunction with an energizer either the FEQ or Atmosphere 

more about these here
https://forum.audiogon.com/discussions/synergistic-research-hft-s?highlight=Synergistic%2BHFTs%2B

I was very skeptical of these but found out 2 other Audiophile friends a state 
over from me had  the older crossover enhancers ,now have the Graphene based Carbon shell models like their Graphene Blue Fuses these filter the high-frequency hash  and the Electromechanical fields within the Xover.
they liked the Carbons noticeably more . They said 75 hours to get about 90% runin then 200 to fully refine . I bought them myself and Dam within 12hours 
i can geara clearer Audio presentation . I have not been a big fan of a lot of 
the Hype Synergistic has done in The past like the active shield I had them sold them , but theirBlue Fuses are very good ,
and I want to see just how much better my speakers get and in which areas after 
I log 200 hours . I will just let play for a solid week ,and then deliver my exact findings with several other ears to judge them.

I use Carbon XOTs. They clean-up EMF at the binding post. They are easy to A/B and, like others have said, send them back if you don't hear a difference. Everybody's ears and systems are different.

I know have over 200 hours and for sure they have gotten.  soundstage is bigger as well as image depth and tone saturation .i bought these on Audiogon under tweaks 
Albert at Highend Audio gave me  free Priority mail shipping ,and make an offer 
maybe took few bucks off I paid around  $400. A true highend bargain  .

So if my speakers are Bi-Wire (four binding posts on each speaker), do I need two pairs of these?

Yes, if you bi-wire then in theory and according to the manufacturer you will need four pair which will set you back around $1K. Not cheap but there is a trial period. Heaven forbid they sound good for then what to do other than fork over the $1K.

Have you tried them labtec? 

Well, I seem to be negligent in answering and for that I apologize. Yes, I am running them and I have two sets per speaker, darn bi-wiring. And I thought I would try them, and then if I was not completely bowled over I would send them back.  And I agree with Audioman58. I was able to haggle a deal with Highend Audio for the four pair. And they never went back. Some will call it snake oil, black magic, nonsense etc. but to me everything that came out of my speakers (DALI Epicon 2) was just so much better. Things were "cleaner", more precise, crisp even, and more air. Soundstaging was not wider but deeper (which was okay as the DALIs through a big soundstage). And what sealed the deal was the bride, who rarely comments, asked me how much I had dropped for new speaker cables, and she assumed it was a lot because, as she said, impossible to get improvements like that without dropping a lot. (She understands about the plateau in the high end; spend a lot to get a small improvement). So,the XOT Carbons are attached, and not going anywhere. Oh, I did take them off one night just for an experiment and the missus yelled at me to fix whatever I had done because the music sounded awful! (Her words).

I'm trying XOT carbon now, just a few hours of burn in. I wonder what kind of improvement to expect after 70-200 hours?

I wonder if SR has any plans to update these? If they incorporated some of the new treatment/materials used on the purple fuses and other products, that would be cool.