[faxer]

Just set up the new flagship speaker from BG Corp. the FS880.
They replaced my prototype LA 800's in walls that we modded to dipole.
They consist of a total of: 12 NE0 10's mids, 32 NEO 3's tweeters and ( 8inch drivers powered by (2) 1200 watt BG amps.

They are the most dynamic, transparent speaker I have ever listened to.
They are so smooth and detailed that 100db feels like 75db.
This lack of strain and effortlessness at high levels is due to many factors
1. active Pass Labs Xover with Gold Point Attenuators
2. Pass XA60.5's on the tweeters
3. Luxman M600A's monos on the Midrange Neo 10's
4. 2400 watts from BG Amps on the woofers

We also use (4) BG 12sb subs along with (2) 6ft tall 15 inch driver transmission line subs

[jimdgoulding]

Congrats on your acquisition.  Want is meant by "active" x-overs?  Thanks.

[faxer]

Active Xover means that you are by passing or not using passive crossovers that can degrade the sound.

With an acitive Xover each amp is feed directly to the exact frequency it needs to drive a specific driver(s) instead of the amp's signals overrriding on top of each other into a passive network where it gets bogged down

So with an active xover your amp is more efficient it produces 4x it's rated power since it has a much easier load to drive   

[jimdgoulding]

That does indeed sound beneficial.

[audio.bill]

Active Xover means that you are by passing or not using passive crossovers that can degrade the sound.

With an acitive Xover each amp is feed directly to the exact frequency it needs to drive a specific driver(s) instead of the amp's signals overrriding on top of each other into a passive network where it gets bogged down

So with an active xover your amp is more efficient it produces 4x it's rated power since it has a much easier load to drive

With all due respect, I beg to differ with some of your points above. Your first assertion is basically correct, although you failed to consider that active circuitry in an active crossover can also degrade the signal. An active crossover is essentially a bandwidth limited filter implemented in preamp circuitry, where the sound quality can be affected by the circuit design, component quality used, and any power supply limitations. Various distortions including phase related issues are often introduced with many active crossover designs. So like anything else in audio there are tradeoffs made with either passive or active crossover circuits and one is not inherently superior to the other.

Your second point again depends upon the relative quality of the active or passive crossover design being used and the various tradeoffs being made. Regarding your third assertion it is true that each amplifier being fed a bandwidth limited signal for a specific driver can operate more efficiently since it doesn't have to handle the other drivers' frequency bandwidths. However I don't believe that the amps are then able to produce 4 times their rated power by handling the easier load, however there may be a perceived gain in the amp's effective power output.

[Ric Schultz]

Yes, an extremely tweaked out active xover is hard to beat.  However, the Pass labs unit is not state of the art.  About as good as there is available as there are very few people making active xovers.  You could tweak it for way better sound.  Same with passive xovers.  A simple 12 db per octave xover like you can use with the BG drivers allows you to use Dueland caps, upcoming copper foil caps from Jupiter and other tweaky passive crossover parts, so that a passive xover would be better than a not so tweaked out active xover.  You can still bi or tri amp using a passive xover.  I really like to have the bass run directly from the amps for super damping factor and control.  The GR Research open baffle servo woofs give you this.  Then you could use a passive xover on the BG mids and highs.  You could use either 6 8 inch servo woofs or 6 12 inch servo woofs per side on a separate baffle and have the same amount of BG drivers as the FS880 on another super dead baffle and wire it with even better wire and use no binding posts and you would have a much better speaker for about one third the price of the FS880 ($35,000 list).  Having completely separate baffles for the bass gives the mids and highs more purity (less vibration) plus it allows you to time align the bass to the mids.  Imagine the bass quality you would have by using either 6 8" or 6 12" servo woofs per channel on an open baffle.....yikes good!  The 8s would give slightly better speed, the 12s would punch you through the wall...he he.

Non the less I bet your speakers sound killer.....I want....but I want what I described....even better.  I will have some day.

[Davey]

With all due respect, I beg to differ with some of your points above. Your first assertion is basically correct, although you failed to consider that active circuitry in an active crossover can also degrade the signal. An active crossover is essentially a bandwidth limited filter implemented in preamp circuitry, where the sound quality can be affected by the circuit design, component quality used, and any power supply limitations. Various distortions including phase related issues are often introduced with many active crossover designs. So like anything else in audio there are tradeoffs made with either passive or active crossover circuits and one is not inherently superior to the other.

Your second point again depends upon the relative quality of the active or passive crossover design being used and the various tradeoffs being made. Regarding your third assertion it is true that each amplifier being fed a bandwidth limited signal for a specific driver can operate more efficiently since it doesn't have to handle the other drivers' frequency bandwidths. However I don't believe that the amps are then able to produce 4 times their rated power by handling the easier load, however there may be a perceived gain in the amp's effective power output.

Actually 4 times the power is correct.  But it might get a little semantic depending upon how you look at it.    Obviously a 100wpc amplifier remains a 100wpc, but you need to think of it as "effective" power since you're using multiple, band-limited power amps.

http://sound.westhost.com/bi-amp.htm#act_vs_eff

Phase-related "issues" are also present with high-level passive crossovers.  There is no inherent advantage or disadvantage in this aspect......unless you venture into the world of linear-phase crossovers utilizing DSP platforms.

Dave.

[rollo]

  I have heard this system. The Pass crossover has been modded. This system IMO is as close to a live performance as it gets. At first being Tri amped I was doubtful KISS is usually my mantra.
    The clarity, presence and natural tone hits ya right in the heart. Emotional impact is off the charts. The four BG subs and amps meld in perfectly. No bloat just well defined and accurate bass.
     I own Pipedreams and for me this may very well be my next purchase. Waiting for the new 660 model which is a bit less in height. We shall see. The model FS 520 and Fs 420 are looking good as well. Not a dealer for BG radia.





charles

[SteveFord]

$35,000 a pair - I would hope they'd sound good!

[SoCalWJS]

Do you have any photos with the grills off and the rear of the speakers?

[rollo]

$35,000 a pair - I would hope they'd sound good!

  Yes $35,000 is a stretch for most. The smaller offering have the same clarity and presence just a smaller sound stage. The bass alone for a panel speaker is worth an audition.


charles

[SoCalWJS]

What is included at that price? Is that just the 2 towers? (4 12" and 2 TL Subs mentioned in first post)

[fredgarvin]

  I have heard this system. The Pass crossover has been modded. This system IMO is as close to a live performance as it gets. At first being Tri amped I was doubtful KISS is usually my mantra.
    The clarity, presence and natural tone hits ya right in the heart. Emotional impact is off the charts. The four BG subs and amps meld in perfectly. No bloat just well defined and accurate bass.
     I own Pipedreams and for me this may very well be my next purchase. Waiting for the new 660 model which is a bit less in height. We shall see. The model FS 520 and Fs 420 are looking good as well. Not a dealer for BG radia.





charles

I'm thinking of picking them up as well, they would sound pretty good out in the shed.








Fred

[Davey]

$35,000 a pair - I would hope they'd sound good!

There's a lot of expensive Chinese neodymium in those speakers. 
However, price points and disposable income are probably not a concern to a person who might purchase these speakers.

Dave.

[SteveFord]

We just did our taxes, I made $10,000 less this year than last year which is not so wonderful.

I guess I'll have to take a pass.

[faxer]

Ok to set the record straight the speakers are modular construction
The woofer sections have their own separate enclosure and are physically apart from the panels they connect to one another via Allen screws 4inch long but again do not share the same cabinet
The panel is made from aircraft aluminum and coated to prevent any vibration from the woofer cabinets
Yes both methods either active and passive have their pros and cons
However after 5 years of R&D with my 2 engineers and consulting with Igor Levitsky engineer at BG we have determined that even the best passive components are not at least in this speaker design optimal as the speakers retain more transparency and volume effortlessness when active Xover is employed
Although these speakers are 93db efficient they like current and like to be played loud at realistic levels
By using active Xover the amps have 4x the power for each planar section and since the amps are pure class A on the panels they always stay in class A and do not have to exhaust their rated power to slide into class AB
The woofers utilized are strategically located in the corners and across the room for bass control and room node elimination
The 4 bg subs are only 4inches in diameter and house 12 of them per woofer for a total of 48 inches of woofer per module
The benefit of this design is that they are lightening fast and are the only woofers aside from a planar woofer that keep up and are as fast as the planers
The transmission line woofers are only set at below 30hz and are set very low to prevent any bloat and blend very well
You are nervier drawn to their attention  unless you are playing Crystal Method
If you look in the left corner of the pix I attached you can see one of the transmission subs-to the right one of the BG sub modules

[faxer]

FYI
The prototypes which were called Dipole 800's were the inspiration for the 880's
The prototypes were sold to Dr. Sakakini and his video can be seen on You Tube
Search words: Bg Radia 800 prototypes
They blew him away which replaced his top of the line Magneplanars

[jimdgoulding]

My experience with active crossovers is with active speakers.  I am told that with active speakers, the delivery of waveforms from convex and concave drivers can be time aligned to coalesce at the listening position.  With conventional surface mounted drivers, high frequency domes, for example, that typically would mean that the tweeter is delayed.  That right?

[Davey]

Jim,

If you utilize active crossovers then you have active speakers.  It's not really necessary to physically integrate crossover/amps within speaker enclosures/boxes to meet the "active speaker" definition.

Regarding time delays.  That can be achieved either physically or electrically or both.  Time delays can be accomplished with a frequency-dependent delay circuit in analog active crossover circuits or frequency-independent delay circuits in DSP active crossovers.  The Pass crossover is an analog unit, but I don't remember if it has any delay circuits in the topology.  If not, and you were concerned about relative delays, then you'd need to physically align the drivers.

Yep, generally, with conventional transducers mounted on the same baffle plane the tweeter acoustic center would be nearer the listening position and require some sort of delay to achieve a phase-coherent response on the design axis.

Cheers,

Dave.

[Ric Schultz]

Gold Point attenuators are really good.  However, they cannot compete with a shunt attenuator done with the same resistors.  You are listening to many resistors in series with a Gold Point attenuator.  Even the solder joints in between each resistor can be heard.  There is no such thing as a perfect resistor or perfect solder......also many feel the LDR attenuators beat any resistor attenuator.  What other mods were done to the Pass xover?  An all out modded Pass would be killer.....but is yours all out?  All the jacks, wire, power supply parts, resistors, caps used in the filters can be upgraded. You can damp parts for better sound and add things like Pulse Gen ZXs, Black Discus, etc.   

You guys listened to a tri-amped 1500hz 12 db per octave passive xover using all top of the line Dueland parts and and you feel the Pass it better?  You don't need anything on the bottom of the Neo 10s except one small cap that can be put directly in front of the midrange amp.  Since it is a low value (something like .03) you can use the worlds best cap (silver Dueland or maybe the new copper Jupiter cap) or if using a tube amp on the mids you can change the coupling caps in the amp to better caps with a lower value.  You would still tri-amp the speakers but there would not be a line level xover only a single cap and coil on the mids and the same on tweet.  If the mids and highs had different sensitivity then you can put two nude Vishay resistors in front of one amp to match the levels.

As long as the woofers are attached directly to the mid/high panel there will be some vibration transmitted.  Aluminum is nice but look what Magico does with their aluminum cabinets to make them even deader.  Two of the woofers are in the back....not at all in time with the other two on the front.

Binding posts suck! he he. So do spades.  I hope you are hardwiring your amps directly to the speakers and not even using spades on the wires.  If you are now using the standard method and you hardwired both at the amp and speaker at the same time you would fall on the floor with the improvement.

My motto is "perfecting never ends".  I hope you take my comments with this in mind.  Your system would bring tears to my ears for sure.  But is it done?  Can you get more?