XPA-DR3 Differential Reference with Speakers Powered SUBs

[ashrum]

Can a fully Differential amplifier be used with tower speakers that have built in powered subwoofers.  I have a pair of Definitive BP-2000's and a CS9080 form my center as the front sound stage in my theater, as well as a pair of Definitive BP-2002TL and CLR 2500 in my Entertainment room. All these speakers have built in powered Subwoofer that are powered by an internal amplifier for the low range of the speakers.  The BP-2000's are wired to receive signal for high, mid and low over the speaker cable across the bridged 3 set of speaker terminals.  The BP-2002TL receive signal to mid and high through speaker wire across the bridged terminal and the low end receives signal through interconnects from the receiver.  Would an amplifier like the XPA-DR3 Differential Reference amp be compatible with speakers like these that have a built in powered subwoofer or would I be better off with something like  XPA HC-1 High Current Monoblock Amplifier for each channel.

[mountain]

I have the Def. Tech. 2000’’s.  My Outlaw 7200  (200 watts x 7 all channels driven, etc.) does a great job driving these speakers.  I think both mentioned amps would do fine as well as the Base X 2 channel amp.  

[localnet]

Yep, either amp(s) will work...

[leonski]

Is there any concern with common ground?

IS the DR3 'bridgeable'?

My Parasounds are commong ground....the Most common type.

But my old carver cube? Was +- / +- for the two channels....with NO common ground.
So to bridge? You could connect +->+ and have a mono amp of about 2x the 4ohm power.....

FROM THE DR3 PRODUCT PAGE:

NOTE: This is a fully balanced amplifier with a floating, differential output stage. The output terminals must NEVER be tied together or ground referenced. Doing so will cause immediate damage that is NOT covered under warranty. If you have any questions about speaker compatibility, please contact Emotiva for technical support.


ME?  I'd take 'em up on the offer of 'technical support' and have model number and such of the speakers in question ready to go.....

[localnet]

Let us know what you discover, I think you will be fine, but I know these differential amps can be funny.

[KeithL]

The XPA-DR amplifiers, as well as ALL true differential amplifiers, have an output that is made up of two identical "bridged channels".
(In other words, the XPA-DR3 is already a "bridged amplifier"... so you can't "bridge it again".)

So....
- NEITHER speaker terminal on each speaker output is at ground potential
- they DO NOT have a common ground
- THEY CANNOT BE CONNECTED TO SOMETHING THAT REQUIRES OR EXPECTS A COMMON GROUND OR FOR THE BLACK SPEAKER TERMINAL TO BE GROUND

So, if you have a powered speaker, or a speaker with a powered subwoofer...
UNLESS IT SPECIFICALLY SAYS THAT IT CAN BE USED WITH A FULLY DIFFERENTIAL OR BRIDGED AMPLIFIER it cannot be used with one of our XPA-DR amps.
(This is not that unusual since there are quite a few modern amplifiers that are fully differential... also including many modern high-powered Class-D amps.)

SOME speakers with powered subs, and some subs with "speaker level connections", are specifically designed to be able to work with differential amps.
And SOME, including some sub model from REL, actually have specific instructions, or special cables and input options, to enable them to do so.
However, if in doubt, you should ask the manufacturer of your speaker.

If you attempt to connect a fully differential amplifier to a powered speaker or subwoofer that "expects or requires" an amplifier with a common ground...
YOU MAY DAMAGE THE SPEAKER, THE AMPLIFIER, OR BOTH.

Sept 25, 2023 16:03:40 GMT -5 ashrum said:

Can a fully Differential amplifier be used with tower speakers that have built in powered subwoofers.  I have a pair of Definitive BP-2000's and a CS9080 form my center as the front sound stage in my theater, as well as a pair of Definitive BP-2002TL and CLR 2500 in my Entertainment room. All these speakers have built in powered Subwoofer that are powered by an internal amplifier for the low range of the speakers.  The BP-2000's are wired to receive signal for high, mid and low over the speaker cable across the bridged 3 set of speaker terminals.  The BP-2002TL receive signal to mid and high through speaker wire across the bridged terminal and the low end receives signal through interconnects from the receiver.  Would an amplifier like the XPA-DR3 Differential Reference amp be compatible with speakers like these that have a built in powered subwoofer or would I be better off with something like  XPA HC-1 High Current Monoblock Amplifier for each channel.

[leonski]

Thanks for the clarification, Keith, ......EXACTLY why I made my post.....from yesterday.

[ashrum]

Thank you all for the information. Based on what Keith mentioned I most likely will end up going with XPA HC-1 mono blocks then. I was thinking about the possibility going with the XPA-DR3 and moving the mono-blocks to my other speakers but based on what Keith mentioned there is a high probability that they will not work with Def. Tech. BP-2000’’s. as they do have powered subs and would quite possibly cause damage to both the amp and the speakers. Now I will just have to wait till the XPA HC-1 High Current Monoblock Amplifier comes back in stock so I can get a matching amp for my center channel.

[ashrum]

Does any one know is the XPA HC-1 will be coming back in stock? or if it has been discontinued? I see there is now XPA-1 Gen3 Monoblock.

To goo off on a bit of a rant, Thought the XPA-1 Gen3 Monoblock seems similar it has a massive case and a lot empty internal space compared to the XPA HC-1. It seems like extra weight and takes a lot more extra shelf space for no reason. I get that it can be upgraded to have extra channels but, those who gravitate to buying mono-block don't usually look to change a Monoblock into a multi-channel amp. The but them for the purpose of either having isolated separately powered channel or having them close to the speakers, for those that think it would be beneficial to have the shortest speaker wire run. This especially benefiting from smaller size case and weight. Except for these purposes, single channel amps are not commonly bought to add additional channels to an existing system as nowadays channel are usually added in pairs with the exception of a center channel. The other was using a single speaker for a surround back channel, but I don't know any one that really does this anymore. I also find it weird looking at the specs of the XPA-1 Gen3 Monoblock. The XPA-1 Gen3 Monoblock should have pretty much the same internals as XPA HC-1, but its specs are 550 watts RMS/channel; 20 Hz – 20 kHz; THD<0.2%; 4 Ohms while the XPA HC-1 is 600 watts RMS; 20 Hz – 20 kHz; THD<0.2%; 4 Ohms. Why does the XPA-1 Gen3 Monoblock have 50 RMS watts less than the XPA HC-1 and only for the 4 ohms specs?

[leonski]

You will never 'notice' the lack of 50 watts except under the most exacting bench test conditions.......

The XPA-1 G3 also says it draws a maximum of 1000 watts. This is also a non-starter since you would only come close to that
doing the same bench testing as you run for maximum power. But given that? If I had 2 or even a 'trio' of these amps, it would be on
a dedicated circuit. At the very highest levels, you will really stress a power line to the amps.....

I would buy a Kill-A-Watt meter and also keep an eye on the lights in the house. My old Carver Cube would cause the lights in the house to flicker
in time to the music when at the very highest levels.....

If you are into 'specification peeping'.....I'd look at power bandwidth and SNR at full power and at some lower power.....which is where you'll spend
MOST of your amp-owning life....

I have a PERSONAL problem with the class 'H' power supply of the HC-1. If you are ever going to hear something you don't like, it'll be when the
amp shifts rails or voltages......
I do Not know what kind of PS the XPA-1 has......Maybe a big switcher with a single voltage? Or even some kind of linear with a giant transformer......
But if that were the case, it would weigh even more.

[KeithL]

The XPA-1 is functionally the same as the XPA HC-1 ... except for the extra expansion slots.
Some people just like a bigger case that matches their other gear or fits in a standard rack.
(It's got a bit more room for cooling air flow... but I would not consider that to be significant.)

The expansion room does offer some interesting options though... 
For example you could use a pair of monoblocks for stereo...
Then later you could add some low power channels to run surrounds...
(You would still be running surrounds in stereo - when you weren't using the surround channels.)

Oct 6, 2023 13:05:50 GMT -5 ashrum said:

Does any one know is the XPA HC-1 will be coming back in stock? or if it has been discontinued? I see there is now XPA-1 Gen3 Monoblock.

To goo off on a bit of a rant, Thought the XPA-1 Gen3 Monoblock seems similar it has a massive case and a lot empty internal space compared to the XPA HC-1. It seems like extra weight and takes a lot more extra shelf space for no reason. I get that it can be upgraded to have extra channels but, those who gravitate to buying mono-block don't usually look to change a Monoblock into a multi-channel amp. The but them for the purpose of either having isolated separately powered channel or having them close to the speakers, for those that think it would be beneficial to have the shortest speaker wire run. This especially benefiting from smaller size case and weight. Except for these purposes, single channel amps are not commonly bought to add additional channels to an existing system as nowadays channel are usually added in pairs with the exception of a center channel. The other was using a single speaker for a surround back channel, but I don't know any one that really does this anymore. I also find it weird looking at the specs of the XPA-1 Gen3 Monoblock. The XPA-1 Gen3 Monoblock should have pretty much the same internals as XPA HC-1, but its specs are 550 watts RMS/channel; 20 Hz – 20 kHz; THD<0.2%; 4 Ohms while the XPA HC-1 is 600 watts RMS; 20 Hz – 20 kHz; THD<0.2%; 4 Ohms. Why does the XPA-1 Gen3 Monoblock have 50 RMS watts less than the XPA HC-1 and only for the 4 ohms specs?

[davidl81]

Oct 6, 2023 13:05:50 GMT -5 ashrum said:

Does any one know is the XPA HC-1 will be coming back in stock? or if it has been discontinued? I see there is now XPA-1 Gen3 Monoblock.

To goo off on a bit of a rant, Thought the XPA-1 Gen3 Monoblock seems similar it has a massive case and a lot empty internal space compared to the XPA HC-1. It seems like extra weight and takes a lot more extra shelf space for no reason. I get that it can be upgraded to have extra channels but, those who gravitate to buying mono-block don't usually look to change a Monoblock into a multi-channel amp. The but them for the purpose of either having isolated separately powered channel or having them close to the speakers, for those that think it would be beneficial to have the shortest speaker wire run. This especially benefiting from smaller size case and weight. Except for these purposes, single channel amps are not commonly bought to add additional channels to an existing system as nowadays channel are usually added in pairs with the exception of a center channel. The other was using a single speaker for a surround back channel, but I don't know any one that really does this anymore. I also find it weird looking at the specs of the XPA-1 Gen3 Monoblock. The XPA-1 Gen3 Monoblock should have pretty much the same internals as XPA HC-1, but its specs are 550 watts RMS/channel; 20 Hz – 20 kHz; THD<0.2%; 4 Ohms while the XPA HC-1 is 600 watts RMS; 20 Hz – 20 kHz; THD<0.2%; 4 Ohms. Why does the XPA-1 Gen3 Monoblock have 50 RMS watts less than the XPA HC-1 and only for the 4 ohms specs?

If I’m not mistaken the HC-1 is identical to the XPA-1 except in a smaller non expanding case. I’m surprised to see any difference in the specs.

[ashrum]

Oct 6, 2023 17:00:24 GMT -5 davidl81 said:

   Exactly the what I was trying to say was strange, If the power supply is the same, the amplifier board is the same and the only difference is the case, why are specs different. Its not that I care about the difference in 50 watts in my usage, I just found it odd there is different in the specs at all. I would be also interested to to know scince they have different listed specs are their switch over from class AB to Class H happens at the same load. (wattage output)

I do hope hope they do get more of the XPA HC-1 back in stock as would like to get an additional one for my center channel to match the ones for my front channels. If it came down to it, I always could make room on my rack for the XPA-1 Gen3 Monoblock, I just would prefer to get the  XPA HC-1 so my front stage amp all match.  I have amps for 15 channels on home theater for movies and 11 channel in my entertainment room for watching tv and other content with no plans to add any more channels to either room, so its unlikely I would need expand from a Monoblock to a multichannel amp in the future in either system. So in my case its mostly a choice of ascetics to have all matching  XPA HC-1s for the front stage. Though I could see my self getting a XPA-DR3 Differential Reference amp if I ever upgrade my front speakers to something that does not have built in powered subs.

[leonski]

That 'Class H' stuff is NONSENSE.
The amp is conventional A/B........this is a bias condition to the output transistors.

That 'G' and 'H' stuff refers to the power supply.....in the case of the amps you are interested in?
Apparently the SAME PS which they cal 'class H'......


H would appear to be 'rails' Most of the time you cruise along on maybe 20 volts available to the power transistors.
They will be happy nearly forever like this and you will spend MOST of your time there.....up to 30 watts or whatever.....
When you demand? Another rail is availble which is at a higher voltage.....60 volts, maybe? And this will provide
lots of juice to maximum output. Such a PS may have 2, 3 or perhaps more steps...

G on the other hand? Kind of turns up the voltage in time with the Demand. Carver did this a LONG time ago and
played with his Tracking power supply and ALWAYS gave his stuff some wacky name or other......
I kind of LIKE this approach....I had one of his early efforts in this regard and it worked fine and overall ran cool.....

One thing from the experience bank? You should kind of choose an amp with the speaker in mind. I've seen
setups with Kliipsch speakers and Kilowatt Mono amps.....which is vast overkill, when 100 watts would still be a lot.

  OR?   Do I have 'G' and 'H' reversed?     

I've got very low sensitivity speakers and 'only' 400 watts each......in the form of a 200x2 stereo amp....and linear PS
   with a largish Toroid and reasonable capacitor bank.....

I'd be VERY curious as to the sensitivity of the speakers in ashrum's setup. And how many seperate circuits he has to
plug everything INTO.....

[ashrum]

Oct 6, 2023 23:16:18 GMT -5 leonski said:

That 'Class H' stuff is NONSENSE.
The amp is conventional A/B........this is a bias condition to the output transistors.

That 'G' and 'H' stuff refers to the power supply.....in the case of the amps you are interested in?
Apparently the SAME PS which they cal 'class H'......


G would appear to be 'rails' Most of the time you cruise along on maybe 20 volts available to the power transistors.
They will be happy nearly forever like this and you will spend MOST of your time there.....up to 30 watts or whatever.....
When you demand? Another rail is availble which is at a higher voltage.....60 volts, maybe? And this will provide
lots of juice to maximum output. Such a PS may have 2, 3 or perhaps more steps...

H on the other hand? Kind of turns up the voltage in time with the Demand. Carver did this a LONG time ago and
played with his Tracking power supply and ALWAYS gave his stuff some wacky name or other......
I kind of LIKE this approach....I had one of his early efforts in this regard and it worked fine and overall ran cool.....

One thing from the experience bank? You should kind of choose an amp with the speaker in mind. I've seen
setups with 100 Kliipsch speakers and big Mono amps.....which is vast overkill, when 100 watts would still be a lot.

I've got very low sensitivity speakers and 'only' 400 watts each......in the form of a 200x2 stereo amp....

I'd be VERY curious as to the sensitivity of the speakers in ashrum's setup. And how many seperate circuits he has to
plug everything INTO.....

To answer that question most of my speakers are 90-92db sensitivity  except for a pair of surrounds I have that are 87db sensitivity, so my issue has never been much of a power issue although the distance to my primary listing position from my front speakers are about 15 feet. I have rarely ever found the need to raise the volume on my preamp past -10db with 200 watts rms at 8 ohms amps.   As for power my theater has four separate 20 amp circuits. I use 2 for my amps and preamps, 1 for my rear sub and my projector and 1 for my front sub and the 3 front speakers with powered subs built in. My entertainment only has 1 20 amp circuit and 1 15 amp  circuit. the 20 amp has 3 amps a receiver and  a oled display. The other 15 amp has 2 sub woofers and room lights on it. I have never had an issue on either with the circuits tripping or being overloaded.

[leonski]

I'm PROUD of you that you have enough circuits for any possible situation without stressing anything out......Makes going forward much easier when you don't have to 'worry'
about power.
My house has only a 100 amp service. Which puts some things off the table...Like SOLAR, for example, which would mean a panel upgrade. I have a 20 amp circuit
for my amplifiers, but the rest is 'shared'. I DO have a 400va Isolation Transformer for low power / digital and that has an effect to the 'good'.....

90 to 92 db sensitive? Not over the top, but certainly much easier to work with than my 80 something panels! Depending on the room size and overall Habits?
Those big Mono's are over the top. But a lot Less So than those guys running the same or similar amps into very high sensitivity Klipsch....
ME? Glad you asked. I'm considering changing my amps and speakers. IF I like them? KLIPSCH Forte IV of about 95db and a VTA 60x2 Tube Amp.....
the kit with tubes is very affordable and the instruction manual quite comprehensive......And I have the skills and tools to pull it off. Give me 2 weeks to build it?

I just GAVE AWAY an OLED set with 22000 or 24000 hours on it. NOT a misprint. It was a B6, so 6 or 7 years old, maybe......
Replaced with a NEW C3 and it is perfecto. I just plugged in a flash drive with large JPG images from a recent vacation and it
really looks like 'you are there'.....ZION National Park....

[ashrum]

True the mono-blocks will have more power than I need, but the front and center speakers can handle 300 watts rms 8 ohms, not that I will ever crank them up that high as I would probably go deaf. I also have a LG B6 that I have move to a bedroom before I had put as many hours as you have put on it. My current main tv is a lg G2, also have the lg 2020 cx in another room. I have slowly been replacing my old Panasonic plasmas with OLEDs. Still have one left from the last year they were made. The plasmas were great back in there days. Now there just can't compete with the brightness, color accuracy and contrast of todays display, not to mention they really are power hogs. They also produced a ton of heat in the room, like a small space heater. Great in the winter, but not so great in the winter.

[leonski]

WAY different situation.
1 main TV in LR and another small on in one bedroom. BR set is used about 3 hours per week....TOPS.

But I must add that speakers DO NOT have watts. And those ratings can vary by method of either calculation or measure.
Speakers also increase in resistance as the copper heats. I can't remember what this effect is called....but it it measurable
and not for the better....
It's OK to have 'more power than you need'.....6db to 10db if possible to measure in advance, maybe. But amps also change
as a function of power output. That distortion you see spec'd? At some high power level.

www.stereophile.com/content/dan-dagostino-momentum-m400-mxv-monoblock-power-amplifier-measurements

Check out the measurement panel from this 'cost no object' amp......The square wave is perfect,

The Best Plasma was probably the Pioneer Kuro. But expensive to buy and used a lot of power. I remember going into a
demo room and it was HOT.....I mean HOT......Uncomfortable. The benefit was reaped by PANASONIC who hired some of
those engineers when Pioneer quit the market. The last couple generations of the Pioneer stuff was GOOD......
Not possible to make a 4k display, I fear, since the cell size would have been very tiny, indeed.

[ashrum]

yes your right speakers don't have watts, It just more of a average measurement of constant power that a manufacturer labels the speakers to prevent people from over driving them and burning out coils. Some speaker can handle a lot more power than they are rated for with out incurring damage. I was just tiring to get across that the my should safely be able to handle the full output of the XPA HC-1 with out damage, not that I ever intend to use that much power to drive that, as I mentioned before I would be more worried about permanent hearing loss rather than damage to the speakers.

[leonski]

My point....not well made.....was that speakers can tolerate less power as they heat.....
And ALL that power turns to heat, one way or another. Your 90+db sensitive speakers, while certainly helpful
with turning 'watts' into sound, are only maybe 2% or LESS efficient.

Its been quite a while since I went over this, but I seem to remember you can have 'peak' watts and 'continuous'
watts for a speaker. I generally figure about 2:1 for these......So a 100 watt RMS (continuous) feed would be
maybe similar to 200 watt 'peaks'......
See if your speaker manufacturer provides this detail. If not? A near-meaningless spec...

MY personal rule of thumb? LISTEN for distortion products. Tweeters are most vulnerable and as it turns out,
your ears are pretty good at hearing THAT kind of nasty screech....or just ordinary break up.....
I think it may be a costly mistake to depend on ANY specification of power 'handling' and amp output to say
that 'my speaker can take the full output of this amp without issue'....
And while true that some speakers can handle more......it is still an experiment to find out just HOW MUCH.

My original Magnepan panels? MG-1 from the beginning.....Sounded wonderful and sucked a 200-a-side Carver Cube right down
to the last electron.....And flickered the house lights in time to the music! But I paid the price over TIME and ended up having them rebuilt at the
factory many year later. I bought 'em used....One of the best moves I ever made......ALL THAT extreme loudness caught up to me!

As an example? MANY years ago I fell in love with the BRAUN LV1020 'TriAmp' speaker. It had a 50 watt woofer amp, 35 watt midrange and 15 watt TWEETER amp.
And they sounded fabulous and played plenty loud......And only 100 watts per speaker! Dome midragne and a dome tweeter get the job done.....

cirris.com/temperature-coefficient-of-copper/#:~:text=The%20Temperature%20Coefficient%20of%20Resistance,the%20resistance%20increases%20by%200.393%25.

Here is a resistance calculator for copper and maybe other metals. As temp RISES due to heating, the RESITANCE also rises....making the problem worse.
Voice coils may have 100c or higher insulation....Not like rubber, but a liquid synthetic. SEE LINK:
Upper limit of 200 c is WACKY hot and would really get the interior of most box speakers pretty darn warm!

ccoils.com/wp-content/uploads/WireInsulationGuide.pdf

I'VE destroyed speakers with too much DISTORTION.....The midrange drivers on my HORRIBLE (mistake to buy 'em) 10" / 3-way speakers......I should have KNOWN better!