Opinion of using the Emotiva XPA-DR1 to power a Martin Logan Focus Center Channel speaker

[Robert D]

Right now I am using the Marantz SR 6014 AVR to power my Focus. I think I could probably do a lot better for that speaker by giving it a dedicated amp. I dont want to spend more than about $1500. I see that the Emotiva XPA-DR1 has decent reviews and plenty of power. Does anyone here own one? Wondering how much of a setp up in sound it will be from what I have now. I imagine a lot! It seems like my setup now lacks some clarity from the center channel when it comes to dialogue during movies. I think it could be better.

I will have to run a cable from my AVR's 12v output signal to this new amp to trigger it on and off. I notice it also has an output jack, so I could daisy chain it to my Aragon amp? I see that my Aragon 2 channel amp doesnt have an output jack, only input. Would that work, chaining it to the Emotiva running off its 12v output jack? Page 8 shows the panel on the back.

xpa_gen3_User_Manual_v32.pdf (shopify.com)

Maybe if anyone here owns one you can answer some questions. I notice this thing is 19 inches deep! Is there a chance that they have the dimensions wrong on the site? It says it is 17 inches wide by 19 deep. My Aragon amp is 19 wide by 15 deep. 19 inches will be a bit deep for the cabinet I have everything in. I suppose I can have some hanging off the back and a little on the front. It looks like the feet come off.

Maybe some of you have an idea for an alternate brand of amp that is $1500 or under. I looked at the Cambridge Edge M monoblock, but its over $4700. It seems like a lot of companies dont make monoblocks. I really dont want to buy another stereo amp and have one channel just sit unused. Edge M - Monoblock Power Amplifier | Cambridge Audio US .Thats the next closest price I could find. Id like to stick to new if I can. It looks like the Emotiva has a 5 year warranty.

I also notice that the Focus speaker has a recommended power input of between 50 and 400 watts. Ive never used an amp rated higher than what the speaker is supposed to have, I dont imagine it is a problem unless you turn the volume up really loud? The Emotiva XPA-DR1 is rated at 650 watts RMS at 8 ohms and 1000 watts at 4 ohms. The AVR is capable of reducing the input on the amp to equal it out to the rest of my system, so wouldnt that correct any issues? Maybe it is overkill and the XPA-HC1 would be better? Its rated at 300/600 watts. Im just figuring that the DR1 is supposed to be their best amp and not only does it have more power but maybe it has higher sound quality as well?

Thanks for any advice. If someone has an idea of another amp let me know.

 

[ttocs]

Well, . . .
If, one were wanting to power a regular ML Hybrid that dips down low, the DR series would not be as good as the HC-1. The DR series definitely does not like low impedance and is specifically recommended for @4Ω and above, but the HC-1 doesn't mind lower impedance.

With that said, the C18 Focus is probably more 4Ω-ish being that is only has a midrange stat panel, so the DR should work fine.

Regarding higher wattage amp than a speaker needs, I don't see a problem with this. I think in this case either amplifier would be fine with the Focus.

 

[Robert D]

Well, . . .
If, one were wanting to power a regular ML Hybrid that dips down low, the DR series would not be as good as the HC-1. The DR series definitely does not like low impedance and is specifically recommended for @4Ω and above, but the HC-1 doesn't mind lower impedance.

With that said, the C18 Focus is probably more 4Ω-ish being that is only has a midrange stat panel, so the DR should work fine.

Regarding higher wattage amp than a speaker needs, I don't see a problem with this. I think in this case either amplifier would be fine with the Focus.

I didn't catch that the HC-1 is better for lower impedance. Something to consider. It's rated power is plenty and it's less expensive.

 

[Robert D]

From what I'm seeing here, the dr-1 is full differential. The HC-1 is not. The DR-1 seems to be thier top of the line amp.

https://emotivalounge.proboards.com/thread/55987/dr-2-hc-1

 

[ttocs]

From what I'm seeing here, the dr-1 is full differential. The HC-1 is not. The DR-1 seems to be thier top of the line amp.

https://emotivalounge.proboards.com/thread/55987/dr-2-hc-1

Yes, the DR series is the top series.

I haven't been able to find any impedance graphs for the C18 yet. I doubt it goes lower than 4Ω by much, and if that's the case, then the DR-1 will work great. But the DR series isn't happy with loads less than 4Ω. I suspect that the 4Ω rating for the C18 is pretty close since the tweeter handles all the frequencies over 3000Hz, so the impedance swing should be ok for amps that have trouble below 4Ω.

Has anyone come across any impedance info on the C18?

 

[Robert D]

Yes, the DR series is the top series.

I haven't been able to find any impedance graphs for the C18 yet. I doubt it goes lower than 4Ω by much, and if that's the case, then the DR-1 will work great. But the DR series isn't happy with loads less than 4Ω. I suspect that the 4Ω rating for the C18 is pretty close since the tweeter handles all the frequencies over 3000Hz, so the impedance swing should be ok for amps that have trouble below 4Ω.

Has anyone come across any impedance info on the C18?

But for some reason the HC-1 handles lower resistance speaker loads better? Youd think their top Amp would do that better. Do you know why the HC-1 fairs better on loads lower than 4 ohm?

I notice that as you add channels to the DR series amps that the stats for power output drop for each channel. Is it possible that the mono block DR-1 will do just as good at a low impendence as the monoblock HC-1? It seems as if something is being shared on the DR series when you start adding in extra amp channels, and the monoblock has the highest power output rating. Up to 1000 watts at 4 ohms.

 

[Robert D]

I see in the stats on their site that both amps say

• Minimum Recommended Load Impedance: 4 Ohms
• (which equals one 4 Ohm load or two paralleled 8 Ohm loads).

 

[Robert D]

Holy crap! I called Emotiva and had a nice live person within 2 minutes on the phone. I am impressed. She was VERY knowledgeable too!

She did confirm that the HC-1 is better with lower impedance loads. She also said that the DR-1, being a differential amp, can be dangerous to use with speakers that are powered. So NOT a good idea to use on Martin Logans! She said with the differential setup, the polarity is switched in the amp since it has 2 separate input voltages. That is not good for powered speakers.

TTdocs, Im glad you came on here! Im also glad I called Emotiva. They impressed me with how fast they answered my question. The lady on the phone knew her stuff too. I was very surprised.

 

[Robert D]

I pulled the trigger and ordered the HC-1. I know we have a member here that recently purchased 3 of them and is very happy. Im sure it will be light years ahead of the sound I am now getting from my Marantz AVR. Im looking forward to it. Thanks for the help in avoiding buying the DR-1.

 

[ttocs]

The DR series amp blades are each two amps running in a bridge mode, so this raises the impedance lower limit. So the DR amps just don't get along with anything less than 4Ω.

I wasn't aware that a differential amp isn't a good idea with hybrid self-powered speakers. Thanks for sharing that.

 

[Robert D]

The DR series amp blades are each two amps running in a bridge mode, so this raises the impedance lower limit. So the DR amps just don't get along with anything less than 4Ω.

I wasn't aware that a differential amp isn't a good idea with hybrid self-powered speakers. Thanks for sharing that.

Yeah, something to do with the polarity on the amp being switched. Thats what she said.

 

[Bonscott]

Holy crap! I called Emotiva and had a nice live person within 2 minutes on the phone. I am impressed. She was VERY knowledgeable too!

She did confirm that the HC-1 is better with lower impedance loads. She also said that the DR-1, being a differential amp, can be dangerous to use with speakers that are powered. So NOT a good idea to use on Martin Logans! She said with the differential setup, the polarity is switched in the amp since it has 2 separate input voltages. That is not good for powered speakers.

TTdocs, Im glad you came on here! Im also glad I called Emotiva. They impressed me with how fast they answered my question. The lady on the phone knew her stuff too. I was very surprised.

Yes I used to have some Def Techs with the powered subs in them. I was considering The DR-3. Emotiva told me the same. Not good for powered speakers. Got the XPA-7 for my ML Motions. Works Fantastic

 

[Robert D]

Yes I used to have some Def Techs with the powered subs in them. I was considering The DR-3. Emotiva told me the same. Not good for powered speakers. Got the XPA-7 for my ML Motions. Works Fantastic

I'm wondering how many members on here are using differential amps with Martin Logan electrostats. I dont know a whole lot about amps, so how common are differential amps? Seems hard to believe we don't by chance have members here using them now. Has anyone that does ever had any problems?

 

[Leporello]

She also said that the DR-1, being a differential amp, can be dangerous to use with speakers that are powered

What exactly does that mean? That neither side of the output can be grounded? I don't see what being differential would have to do with using with speakers that are powered, unless both sides are separately referenced to ground, in which case it isn't true differential.

 

[Robert D]

What exactly does that mean? That neither side of the output can be grounded? I don't see what being differential would have to do with using with speakers that are powered, unless both sides are separately referenced to ground, in which case it isn't true differential.

It's beyond my understanding. I think she said something about polarity maybe being reversed. Not sure.

Call them up and ask. I got through really fast. After she told me that I made sure not to buy one of those amps. She sold me on the less expensive amp. To me that's a good sign, about being honest

 

[Brandon Hartwick]

I believe the emotiva differential amps use a pair of bridged amplifier boards to make up a single channel. Amplifiers lose low impedance stability when bridged and Martin Logan speakers are typically 4 ohm nominal so you're likely on the edge of what the amp can handle.

 

[ttocs]

A bridged amp has 2 HOTS, not a HOT and a GROUND as an output to a speaker. Neither speaker output terminal is connected to ground. This is why Rel specifically explains how to wire their subwoofer to a differential amp as connecting the Hot lead for the subwoofer to the Red terminal on the amp and leave the Black Ground wire from the sub disconnected.

 

[iluvboxing]

What exactly does that mean? That neither side of the output can be grounded? I don't see what being differential would have to do with using with speakers that are powered, unless both sides are separately referenced to ground, in which case it isn't true differential.

I agree, Leporello. I talked with Martin Logan about this topic, and they disagreed. Also, many Magenpan users use differential amps to power their setups with no issues.

I also think about scores of end users that utilize differential amplifiers from PS Audio and ATI Pure Balanced designs. I cannot find end users who have issues with planar or electrostatic speakers, whether passive or powered.

I'm about to buy a pair of Emotiva XPA-1 Gen 2s from a dealer who ran several of them in his theater with Magnepans. He had no issues.

 

[ttocs]

I agree, Leporello. I talked with Martin Logan about this topic, and they disagreed. Also, many Magenpan users use differential amps to power their setups with no issues.

I also think about scores of end users that utilize differential amplifiers from PS Audio and ATI Pure Balanced designs. I cannot find end users who have issues with planar or electrostatic speakers, whether passive or powered.

I'm about to buy a pair of Emotiva XPA-1 Gen 2s from a dealer who ran several of them in his theater with Magnepans. He had no issues.

You won't have trouble with the XPA-1 Gen2 amp and ML speakers or Magnepans. It's not the same design as the XPA-DR series amps from Emotiva which are a Bridged design so speakers lower than 4Ω are too low for this amp series.

As far as I know the ML Masterpiece speakers are not a Common Ground design. I just checked mine and there is no common connection between Ground and either speaker terminal so any amp should work fine with regards to the ground issue, whether differential or not. A bridged amp is a different matter, as bridging reduces stability into low impedance loads.

An example of a Common Ground component that can be connected to an amplifier, but should not be "fully" connected to a differential amp, is a subwoofer like my Rel. My Rel is a Common Ground design. The Black wire should not be connected to the Negative speaker output terminal of a differential amplifier, but instead, it should be left unconnected. The reason is that the Rel's Black wire is connected to Ground, all the way to the power outlet.

 

[iluvboxing]

I'm wondering how many members on here are using differential amps with Martin Logan electrostats. I dont know a whole lot about amps, so how common are differential amps? Seems hard to believe we don't by chance have members here using them now. Has anyone that does ever had any problems?

I'm powering a pair of Aerius i with XPA-1 Gen monoblocks. I'm not having any issues besides the speakers being too bass shy.