GR-Research Line Force First Transparent Speakers?

+1. Given how good the NX-Oticas sound, if Danny says these are better, I have confidence they will really be something special.

@bdp24 +1.  I have speakers with GR's Neo3 and they sound fabulous. I'm sure Danny will eventually have a Neo10 replacement as well, but he's not going to put it into production until he's completely satisfied that is as good or better than the original. 

I've been waiting to finish building these speakers for two years. I ordered enough Bohlender-Graebener NEO10 drivers from Parts Express before they became unavailable. But the company building the cabinets for me ran into Covid supply chain issues with the special composite material the cabinets are made from. I finally got the cabinets a few weeks ago and got them built up.

They only have about 25 hours on them so far, but they sound glorious. I can't wait until the crossovers are fully broken in. 

The Line Forces are being driven by DIY 300B Parallel SET monoblocks with WE new-issue tubes. The servo-controlled open-baffle woofers (three 12" drivers/channel) handle from about 170Hz and are powered by Rythmik 370W class A/B amps. 

@bdp24 - Thanks. I might have mentioned that I owned Tympani IVs in the mid 80's. I used Entec subwoofers (one of the first servo controlled designs), but I was never able to get these to fully integrate. I imagine that your OB subs work MUCH better. 

I'd be happy to have you over for an audition once my Line Forces are broken-in (probably a couple months for these crossover caps). 

I've always been intrigued by the Infinity IRS and Genesis One, but didn't have the budget or space for them. When I heard about the Line Forces, the idea of building a modern (and more compact) interpretation of these designs with more advanced and efficient drivers was exciting. 

It took a while to work out the details since these speakers weren't in production, but I've finally been able to complete them. Unlike the IRS and Genesis One, these are quite efficient at 98db/w, and easy to drive (impedance never drops below 5ohms), so they are a good match for low-power SET amps. 

These drivers are very clean and dynamic. The well-reviewed PS-Audio FR-30 uses similar planar drivers, but using a large number of them all but eliminates thermal compression, improves efficiency, and further reduces distortion. It also allows the drivers to play lower. 

@jerryg123 - Thanks. I haven't had a chance to work on optimizing position or sub settings yet, but just plopped down they sound stunning. The detail is better than my Audeze LCD-2 headphones and vocals sound like the singer is right there in front of you. It will be interesting to hear how the sound progresses as they break-in, but I'm already thrilled.

I decided to make the investment to build these having never heard them, based only on my satisfaction with the NX-Oticas and comments from the few people that heard the early prototypes. so I am glad they are living up to the hype.

@bdp24 - Thanks for your summary.

I forgot to answer your question regarding my NX-Oticas. I've actually passed these on to my son, so he and his wife are enjoying them down in San Diego. 

Danny is still working to bring the Line Forces (and other designs based on the NEO10) back to market. He is working with his NEO3 supplier to come up with a viable NEO10 replacement - so far, he hasn't been satisfied with the prototypes he's received, and Covid supply chain issues have really impeded progress.

He is also working on a Line Force crossover using the GRS 10" planar drivers available from Parts Express. This driver does not measure nearly as well as the BG NEO 10, but with the appropriate crossover filters, Danny should be able to come up with a fairly flat response although probably not with the same efficiency.