Another newbie question, albeit a slightly nuanced one :)

[bugsnest]

So I was trying to add a 3-channel Amplifier to my family room setup. My Marantz AVR really doesn't do much to power my LCR (KEF LS50). I was basically trying to replicate my basement home theater setup where I added a Emotiva XPA-3 ahead to my Integra Receiver to power my Paradigm LCR and that works great.

Anyway, this being the family room, I did not want to spend a lot so got a refurbished Niles SI-2150 Class-D amp (2-channel)........... It turned out to be SO underwhelming!!!
Just lifeless, flat and unexciting. This is my first Class-D amp so I am not sure if that's to be expected.

For comparison, I added my Emotiva into the mix and its like the KEF's just came alive!

So, my question(s):

1) Is this as good as it gets with a Class -D amp? The KEF's don't require much power but this does nothing beyond what my AVR does. Are these other Class-D amps out there, in the $500 range (used works too) that I ought to be looking at

2) Are the newer Emotiva BasX series, as good as older XPA's?
I like the form factor, so was wondering if that's the way to go.

 

[RayDunzl]

Niles SI-2150 Class D Amplifier Review

This is a review and detailed measurements of the Niles SI-2150 Class D amplifier. It is on kind loan from a member. He purchased it refurbished and I see it for sale at $367. Original cost seems to be US $850. By using efficient Hypex UcD250LP class D amplifier modules, the SI-2150 manages...

www.audiosciencereview.com

 

[RayDunzl]

It turned out to be SO underwhelming!!!
Just lifeless, flat and unexciting.

Volume matched?

 

[kemmler3D]

The Niles amp shows some impedance/frequency dependence and the LS50 has an impedance peak around 1500hz, so MAYBE you are hearing a bit of a whiff in the mids from this amp. Other than that I can't think of a reason it would sound good or bad, it's a broadly competent class-D amp with decent wattage.

I would suggest finding something that is less speaker-dependent if you switch amps at all.

But, before that, can you describe more specifically what you mean by "lifeless' or "unexciting"?

The Emotiva amps sometimes have A TON of distortion. Sometimes distortion sounds good and lively. So it's possible you're missing that extra sprinkle of THD / IMD with the much cleaner Class D.

A @RayDunzl points out it's also incredibly important to make sure the levels are matched when comparing amps. 1-2dB is hard to hear when adjusting volume, but an extra dB or two makes things sound more alive and generally better.

 

[HarmonicTHD]

Tone control in the AVR all neutral? Audyssey off?

 

[bugsnest]

The Niles amp shows some impedance/frequency dependence and the LS50 has an impedance peak around 1500hz, so MAYBE you are hearing a bit of a whiff in the mids from this amp. Other than that I can't think of a reason it would sound good or bad, it's a broadly competent class-D amp with decent wattage.

I would suggest finding something that is less speaker-dependent if you switch amps at all.

But, before that, can you describe more specifically what you mean by "lifeless' or "unexciting"?

The Emotiva amps sometimes have A TON of distortion. Sometimes distortion sounds good and lively. So it's possible you're missing that extra sprinkle of THD / IMD with the much cleaner Class D.

A @RayDunzl points out it's also incredibly important to make sure the levels are matched when comparing amps. 1-2dB is hard to hear when adjusting volume, but an extra dB or two makes things sound more alive and generally better.

I can’t articulate the problem technically. But I played around with the gain in the amp to see if it would make a difference and it didn’t.

The lifeless part was the audio just sounds flat and muddled. No imaging or dimensionality. Just uninteresting. The Emotiva brings out the magic in the speakers.

Sorry, like I said, I can’t articulate it technically

EDIT: I missed adding that the Emotiva brings out a nice, loud yet clean bass in the speakers. The Niles did nothing for the bass

 

[RayDunzl]

I see the Niles has level controls on the backside.

Are they set appropriately?

 

[bugsnest]

I see the Niles has level controls on the backside.

Are they set appropriately?

View attachment 327009

I set it at the 12 o'clock position first (as per the manual) and then dialed it all the way up. Didn't really do much as far as I could tell

 

[RayDunzl]

Oh well...

 

[kemmler3D]

I can’t articulate the problem technically. But I played around with the gain in the amp to see if it would make a difference and it didn’t.

The lifeless part was the audio just sounds flat and muddled. No imaging or dimensionality. Just uninteresting. The Emotiva brings out the magic in the speakers.

Sorry, like I said, I can’t articulate it technically

EDIT: I missed adding that the Emotiva brings out a nice, loud yet clean bass in the speakers. The Niles did nothing for the bass

Hmm, well, that almost sounds like something is broken or connected wrong, properly functioning amps don't really have a way to change soundstage or bass. Of course, unless you are just getting euphonic distortion from the Emotiva, which is possible.

 

[bugsnest]

Hmm, well, that almost sounds like something is broken or connected wrong, properly functioning amps don't really have a way to change soundstage or bass. Of course, unless you are just getting euphonic distortion from the Emotiva, which is possible.

“Euphoric distortion”, as in the amp is producing crap but I’m perceiving it as spectacular sound?

I guess I need to get my amp and my head checked!

 

[kemmler3D]

“Euphoric distortion”, as in the amp is producing crap but I’m perceiving it as spectacular sound?

I guess I need to get my amp and my head checked!

Sort of, but it's not really a bad thing.

"euphonic" means good-sounding (vs. euphoric, good-feeling).

Long story short, amps that produce a lot of harmonic distortion (THD) sometimes sound really good to people.

This makes sense. Certain kinds of distortion are generally considered "nice". Case in point - adding distortion to recordings in the studio to add "warmth" or "life" is basically universal. Look at how many audio production plugins boast "tube emulation" or "true analog sound" and you'll see what I mean.

Emotiva amps sometimes have really high harmonic distortion (at least compared to the Niles amp), so this could explain it, although "a lot" in today's world is still "barely audible" in technical terms, so I am not super-confident in this explanation. A totally dead, no-bass, no-stereo sound is more like what happens when you short the left and right channels somehow.

There is a philosophical debate on whether it's right to add distortion after the musicians and producers have already added as much distortion as they see fit in the studio.

And, as far as the concept of "high fidelity" goes, the aim is to eliminate distortion to the greatest extent possible.

But most people here will not blame you if you simply decide you like the sound of amps with high THD. It's a valid preference and there are more than a handful of threads here where people have found they really like the sound of amps which have insane levels of distortion compared to a typical Class-D.

Also, welcome to ASR!

 

[bugsnest]

Sort of, but it's not really a bad thing.

"euphonic" means good-sounding (vs. euphoric, good-feeling).

Long story short, amps that produce a lot of harmonic distortion (THD) sometimes sound really good to people.

This makes sense. Certain kinds of distortion are generally considered "nice". Case in point - adding distortion to recordings in the studio to add "warmth" or "life" is basically universal. Look at how many audio production plugins boast "tube emulation" or "true analog sound" and you'll see what I mean.

Emotiva amps sometimes have really high harmonic distortion (at least compared to the Niles amp), so this could explain it, although "a lot" in today's world is still "barely audible" in technical terms, so I am not super-confident in this explanation. A totally dead, no-bass, no-stereo sound is more like what happens when you short the left and right channels somehow.

There is a philosophical debate on whether it's right to add distortion after the musicians and producers have already added as much distortion as they see fit in the studio.

And, as far as the concept of "high fidelity" goes, the aim is to eliminate distortion to the greatest extent possible.

But most people here will not blame you if you simply decide you like the sound of amps with high THD. It's a valid preference and there are more than a handful of threads here where people have found they really like the sound of amps which have insane levels of distortion compared to a typical Class-D.

Also, welcome to ASR!

That’s fair. I read that incorrectly as “euphoric” which implied I was imagining good sound. lol

I I can’t comment on the distortion level of my Emotiva but my other amp is a McIntosh 452 (for dedicated 2-channel listening) and while the Emotiva doesn’t sound as warm, tight and authoritative as the Mac, it does have decent resolution and imaging, which I found missing in the Niles. From your explanation it sounds like that “flatness” might be a feature and not necessarily a bug for Class D’s. So maybe that’s not suited to my taste.

 

[kemmler3D]

“flatness” might be a feature and not necessarily a bug for Class D’s. So maybe that’s not suited to my taste.

I think it's all relative. If you are coming from something with noticeable THD to something with none, either you'll think it sounds clean and pure, or maybe "sterile" or flat. One man's "pure" is another man's "under-seasoned", if that makes sense.

That said the Niles amp is not a textbook perfect Class D, so if you are looking to settle the matter once and for all, the Ncorex or Purifi-based Class D amps are SOTA and generally more than capable of powering the LS50. So I would look into those if you want to upgrade or experiment - IIRC Buckeye does 3-channel amps with those modules and is well-regarded around here.

 

[RayDunzl]

Are the newer Emotiva BasX series, as good as older XPA's?

Emotiva BasX A-100 Review (stereo amplifier)

This is a review and detailed measurements of BasX A-100 Class AB amplifier. It was kindly purchased by a member and drop shipped to me for testing. The A-100 costs US $229 from the company direct. I must stay, this is one gorgeous looking and nicely feeling amplifier: This is a deep...

www.audiosciencereview.com

 

[MaxwellsEq]

It is worth noting that the Emotiva XPA-3 has the root of "emotive" in it. The Niles SI-2150 has "nil" in its name.

Silver = bright
Copper = soft
Lots of Kg = bass

 

[MaxwellsEq]

Perhaps I should develop an amplifier and call it "ScreamX" and see what the reviews say...

 

[Cbdb2]

So I was trying to add a 3-channel Amplifier to my family room setup. My Marantz AVR really doesn't do much to power my LCR (KEF LS50). I was basically trying to replicate my basement home theater setup where I added a Emotiva XPA-3 ahead to my Integra Receiver to power my Paradigm LCR and that works great.

Anyway, this being the family room, I did not want to spend a lot so got a refurbished Niles SI-2150 Class-D amp (2-channel)........... It turned out to be SO underwhelming!!!
Just lifeless, flat and unexciting. This is my first Class-D amp so I am not sure if that's to be expected.

For comparison, I added my Emotiva into the mix and its like the KEF's just came alive!

So, my question(s):

1) Is this as good as it gets with a Class -D amp? The KEF's don't require much power but this does nothing beyond what my AVR does. Are these other Class-D amps out there, in the $500 range (used works too) that I ought to be looking at

2) Are the newer Emotiva BasX series, as good as older XPA's?
I like the form factor, so was wondering if that's the way to go.

Are you fast switching between the (matched level) amps or are there minute long delays?

 

[bugsnest]

Are you fast switching between the (matched level) amps or are there minute long delays?

Sorry I’m not sure I even know what that means so I’m probably not doing that

 

[MaxwellsEq]

Sorry I’m not sure I even know what that means so I’m probably not doing that

There's evidence that two identical amplifiers will sound different if one is even 0.1% louder than the other (we all prefer the louder amplifier).

This means that if you have two amplifiers which are different but both operating inside their design zones and which are level matched, they both sound identical.