NAD C375BEE to drive Revel F208

[DanielT]

Hi, I wanted to share that I’ve decided to purchase the Salon 2s. The story behind this pair is that the dealer had a previous owner who upgraded to something supposedly more expensive. In the second leg of the deal, they bought the speakers back-presumably at a huge discount. Perhaps they were so happy with the deal's first leg that they were eager to move the lightly used Salons quickly rather than keep them in their inventory. You wouldn’t believe the ridiculous price I got them for.

These will be the most expensive speakers I’ve ever purchased though. Even more remarkable is that I bought them without ever auditioning them - the speakers were more than a thousand miles away. I spent a lot of time researching the Salon 2s, given my limited grasp of physics. Honestly, the research was so time-consuming that I just wanted to wrap it up and refocus on my profession. The majority of reviews and comments I found for the Salons were overwhelmingly positive, and I’d say 90% of my decision was influenced by what I learned here on ASR-even though Amir hasn’t reviewed the Salon 2s yet. This is another example of how this forum can significantly influence consumer behavior.

The speakers are in the hands of a logistics company, with an ETA of Monday. The dealer will come over to install them-which they should, because there’s no way I can handle them on my own. I’m both excited and nervous.

I’ve heard horror stories about shipping mishaps. While I’d get my money back in case of damage, that’s not what I want-I want my Salon 2s after all the time I spent researching. I’ve also read from ASR that someone bought KEF Blades and wasn’t particularly impressed, so there’s always that possibility with the Salon 2s too. And I even read also here about a miswired pair that had to be sent back to Harman.

I just hope they impress me as much as they have other Salon 2 owners in this forum. Wish me luck!

Good luck and congratulations on your exciting speaker purchase.

After you get them home, tell us how you think they sound.

 

[Nothingness]

The Salon 2s arrived safe and sound in pristine condition. The logistics company handled them excellently. These speakers are heavy and look massive in my room. They came with cones, making them easier to move, so I didn’t need to place paper beneath them for toe-in like Brad suggested. I’m not sure if the cones are standard accessories or if the dealer included them as a bonus—I didn’t ask.

Since I don’t have a dedicated listening room, the Salons will stay in the living room, which isn’t ideal acoustically. I drew a floor plan for your reference. I rearranged the sofa so there was no back wall directly behind me. The dealer and I positioned the speakers in the corners—not a tough job, thanks to the cones.

(arrangement 1)

Then I turned on the music. I played Earthquake by Jisoo (from Blackpink), a song my wife loves. It has solid bass that I’ve heard from my B&W 683s and when auditioning the KEF R7 Metas. To my horror, the bass was minimal—almost nonexistent. I previously said I wasn’t sure what I was looking for in this upgrade, but at that moment, I knew: the deep, strong bass others had described—where you supposedly don’t even need a sub.

My jaw nearly hit the floor. I looked at the dealer, perplexed. He admitted the bass was weak, but I couldn’t fully trust his opinion—psychoacoustics might have influenced him based on my reaction. This was all subjective, of course—I didn’t take any measurements, so take it for what it’s worth.

We checked the connections, shifted the speakers a few inches here and there, played some other songs, but the bass remained disappointing. There was no “deep and punchy” bass like others had described. I felt exactly like my friend years ago when he replicated my setup but didn’t get the same sound in his room. I suspected my open living room, which connects to the dining area and kitchen, was the culprit.

Eventually, we had to rearrange everything, placing the sofa against the back wall—something I didn’t like, but there was no other choice. The speakers now looked monstrous next to the rack and TV. We played Earthquake again, and the bass improved, but my initial disappointment still lingered. After some final tweaks, the dealer left.

(arrangement 2)

Edit: I should have clarified that before I have my Salon 2s the old B&Ws were positioned as shown in the Arrange 2 floor plan. The wall reflectivity helped boost the bass a bit.

With this arrangement, I'll be listening from my rocking chair, which is only about 7 feet from the speakers - not an ideal position considering the Salon 2s' tweeter height.

Then came the real test—my wife came home. Her first comment? "These speakers are huge and throw off the balance of the room." I played some songs for her, still recovering from my shock. Her verdict? "Not better than our B&W 683s." I had no idea what to say. Then she asked, "Can you return them? Or resell them?" To which I replied, "Maybe, but I’d lose at least $1K." That potential loss instantly changed her mind (lol), and she never mentioned reselling again.

Later, we played a speaker recognition game. While she was cooking, I switched between the 683s and the Salon 2s. She correctly identified them nine out of ten times—without even trying. When I asked how she could tell, she said, "They sound totally different. The 683s blend everything—the singer’s voice and instruments mix together. The Salon 2s are more detailed—you can hear layers of sound. And the B&Ws sound warmer." This was coming from someone who wasn’t an audiophile before!

After a few days, she started to like the Salons, though she still loves the 683s. So, we’re keeping both.

I’ve somewhat recovered from the initial shock. I can’t hear details as well as she does, as I have mild hearing loss at 4k-7k Hz from concert-going. I can’t comment much on the mids and highs, but I can hear bass perfectly. That said, I’m starting to enjoy the Salons more and more. Now, I’m waiting on some acoustic absorbers to arrive. At some point, I’ll just have to be content with my room.

This whole experience reinforced an important lesson: room acoustics matter—a lot. As they say, “Bass is very room-dependent.” And I couldn’t agree more.

On another note, my NAD C375BEE drives the Salon 2s perfectly at my volume level. I couldn’t find the app Daniel recommended, but I installed SPLnFFT for $3.99, and it works well. I’m not sure which measurement to use—dB, dB(A), dB(B), or dB(C)—but my listening level seems to be around 75-80dB. If anyone knows which measurement is most appropriate for music listening, please advise. At this point, I don’t see any reason to upgrade my amp unless it fails with age.

 

[Old_School_Brad]

Thank you for the update!

This is the spectrum of the song you mentioned:

Spoiler: Earthquake - JISOO

Was arrangement 1 where your other speakers were positioned? The bass response from room modes should be similar for the Salons. However, the Salons might be less bass-heavy compared to your other speakers.

My point is, if the Salons were placed in the same position as your B&Ws in arrangement 1, you'd likely get the same or even more bass from the Revels, if you applied some EQ. Your system should be able to handle a +3dB boost in the bass.

Edit; after finding the response curves, the Revel Salon 2 should produce more bass than the B&W 683.

Frequency response Revel Salon 2:

Frequency response B&W 683 S2:

 

[Nothingness]

Thank you for the update!

This is the spectrum of the song you mentioned:

Spoiler: Earthquake - JISOO

View attachment 440897

Was arrangement 1 where your other speakers were positioned? The bass response from room modes should be similar for the Salons. However, the Salons might be less bass-heavy compared to your other speakers.

My point is, if the Salons were placed in the same position as your B&Ws in arrangement 1, you'd likely get the same or even more bass from the Revels, if you applied some EQ. Your system should be able to handle a +3dB boost in the bass.

Frequency response Revel Salon 2:
View attachment 440903

Frequency response B&W 683 S2:
View attachment 440904

Hi Brad, thank you very much for your comment. Yes, the old speakers were positioned where the Salons are now. Based on measurements and specs, the Salon 2s should have stronger bass. However, I can't say for certain which one has deeper bass purely from memory, given the effects of psychoacoustics. I feel like the Salons do though.

Mine were the original 683s, not the S2 version.

By the way, what app did you use for the song’s spectrum? Is there a free version available? That looks really cool!

 

[Old_School_Brad]

Hi Brad, thank you very much for your comment. Yes, the old speakers were positioned where the Salons are now. Based on measurements and specs, the Salon 2s should have stronger bass. However, I can't say for certain which one has deeper bass purely from memory, given the effects of psychoacoustics. I feel like the Salons do though.

Mine were the original 683s, not the S2 version.

By the way, what app did you use for the song’s spectrum? Is there a free version available? That looks really cool!

It would have been interesting to record 30 seconds of the song with the B&Ws at a specific average SPL and compare the C-weighted peaks with the Salons.

The software I use is Audacity, which is free.

I also have a fun program called Sonic Visualizer, and it's free as well. This is from that Earthquake song where it digs deep.

 

[Nothingness]

It would have been interesting to record 30 seconds of the song with the B&Ws at a specific average SPL and compare the C-weighted peaks with the Salons.

The software I use is Audacity, which is free.

I also have a fun program called Sonic Visualizer, and it's free as well. This is from that Earthquake song where it digs deep.

View attachment 440906

Is it possible to record it as you suggested without having to move the old speakers to the Salons' position? I assume that would be necessary for accuracy. While it does sound fun to me as well, unfortunately, I don't think I can manage it for 'logistical reasons,' haha.

 

[DanielT]

The Salon 2s arrived safe and sound in pristine condition. The logistics company handled them excellently. These speakers are heavy and look massive in my room. They came with cones, making them easier to move, so I didn’t need to place paper beneath them for toe-in like Brad suggested. I’m not sure if the cones are standard accessories or if the dealer included them as a bonus—I didn’t ask.

Since I don’t have a dedicated listening room, the Salons will stay in the living room, which isn’t ideal acoustically. I drew a floor plan for your reference. I rearranged the sofa so there was no back wall directly behind me. The dealer and I positioned the speakers in the corners—not a tough job, thanks to the cones.

View attachment 440894
(arrangement 1)

Then I turned on the music. I played Earthquake by Jisoo (from Blackpink), a song my wife loves. It has solid bass that I’ve heard from my B&W 683s and when auditioning the KEF R7 Metas. To my horror, the bass was minimal—almost nonexistent. I previously said I wasn’t sure what I was looking for in this upgrade, but at that moment, I knew: the deep, strong bass others had described—where you supposedly don’t even need a sub.

My jaw nearly hit the floor. I looked at the dealer, perplexed. He admitted the bass was weak, but I couldn’t fully trust his opinion—psychoacoustics might have influenced him based on my reaction. This was all subjective, of course—I didn’t take any measurements, so take it for what it’s worth.

We checked the connections, shifted the speakers a few inches here and there, played some other songs, but the bass remained disappointing. There was no “deep and punchy” bass like others had described. I felt exactly like my friend years ago when he replicated my setup but didn’t get the same sound in his room. I suspected my open living room, which connects to the dining area and kitchen, was the culprit.

Eventually, we had to rearrange everything, placing the sofa against the back wall—something I didn’t like, but there was no other choice. The speakers now looked monstrous next to the rack and TV. We played Earthquake again, and the bass improved, but my initial disappointment still lingered. After some final tweaks, the dealer left.

View attachment 440895
(arrangement 2)

With this arrangement, I'll be listening from my rocking chair, which is only about 7 feet from the speakers - not an ideal position considering the Salon 2s' tweeter height.

Then came the real test—my wife came home. Her first comment? "These speakers are huge and throw off the balance of the room." I played some songs for her, still recovering from my shock. Her verdict? "Not better than our B&W 683s." I had no idea what to say. Then she asked, "Can you return them? Or resell them?" To which I replied, "Maybe, but I’d lose at least $1K." That potential loss instantly changed her mind (lol), and she never mentioned reselling again.

Later, we played a speaker recognition game. While she was cooking, I switched between the 683s and the Salon 2s. She correctly identified them nine out of ten times—without even trying. When I asked how she could tell, she said, "They sound totally different. The 683s blend everything—the singer’s voice and instruments mix together. The Salon 2s are more detailed—you can hear layers of sound." This was coming from someone who wasn’t an audiophile before!

After a few days, she started to like the Salons, though she still loves the 683s. So, we’re keeping both.

I’ve somewhat recovered from the initial shock. I can’t hear details as well as she does, as I have mild hearing loss at 4k-7k Hz from concert-going. I can’t comment much on the mids and highs, but I can hear bass perfectly. That said, I’m starting to enjoy the Salons more and more. Now, I’m waiting on some acoustic absorbers to arrive. At some point, I’ll just have to be content with my room.

This whole experience reinforced an important lesson: room acoustics matter—a lot. As they say, “Bass is very room-dependent.” And I couldn’t agree more.

On another note, my NAD C375BEE drives the Salon 2s perfectly at my volume level. I couldn’t find the app Daniel recommended, but I installed SPLnFFT for $3.99, and it works well. I’m not sure which measurement to use—dB, dB(A), dB(B), or dB(C)—but my listening level seems to be around 75-80dB. If anyone knows which measurement is most appropriate for music listening, please advise. At this point, I don’t see any reason to upgrade my amp unless it fails with age.

View attachment 440896

Congratulations on getting your Salon 2.

So regarding bass. You still have your B&W 683. Listen to a B&W 683 vs a Salon 2 placed in the same place. Subjectively big difference in bass then? Then both B&W 683 vs both Salon 2 placed in the same place (there will be a little movement of speakers when you test). Subjectively big difference in bass then?

Incidentally, have you double-checked that you have connected the speakers correctly, so that +/- are not connected differently on the speaker terminals/on the speaker outputs on the amplifier?

Have you tried playing really low-frequency bass music, or continuously low bass tone and seen if the eight bass drivers in your in your two Salon 2 seem to move in unison and and with equal movements? This is to rule out any radical problem, if any bass driver is more or less broken, that is.

Edit:
Regarding troubleshooting, there are a lot of people here at ASR who are more knowledgeable than me who can give you tips and advice. Or your Salon 2 is not broken. Then it is the bass they produce in your listening room.

 

[JeremyFife]

You can still make recordings as @Old_School_Brad suggests with the speakers in different positions: they won't work for accurate comparison but they will still help you get some objectivity into what you are (subjectively) hearing. That may help you understand what is happening.
By the same logic, measurements of both speakers will still be useful if you wanted to try that.

 

[Old_School_Brad]

Is it possible to record it as you suggested without having to move the old speakers to the Salons' position? I assume that would be necessary for accuracy. While it does sound fun to me as well, unfortunately, I don't think I can manage it for 'logistical reasons,' haha.

No, the position should remain the same as it was originally for a proper comparison. Room modes are excited differently depending on speaker placement. It was just a fun little experiment -no need to wrestle heavy speakers for it.

 

[DanielT]

It would have been interesting to record 30 seconds of the song with the B&Ws at a specific average SPL and compare the C-weighted peaks with the Salons.

The software I use is Audacity, which is free.

I also have a fun program called Sonic Visualizer, and it's free as well. This is from that Earthquake song where it digs deep.

View attachment 440906

All sensible types of objective measurements are worth doing.

With a microphone would be the best approach.

 

[Old_School_Brad]

All sensible types of objective measurements are worth doing.

With a microphone would be the best approach.

An iPhone with the NIOSH app will work just fine. This is more of a practical reality check since OP mentioned a lack of bass. "Fun" might be a stretch, especially if it involves moving heavy speakers -I probably wouldn't bother myself. Well, maybe, if I really thought something was off. Money spent should always bring an upgrade. -Says the penny-pincher.

 

[Nothingness]

Thank you all very much for your kind help-I truly appreciate it.

Let’s say I can arrange the speakers so their positions are nearly identical. By the way, thanks to the cones, the Salon 2s are easier to reposition than the 683s, which weigh about 70 lbs, if I remember correctly. What app should I use to record the songs and check the C-weighted peaks, as per Brad's suggestion? I’m really a novice when it comes to testing and measurement, so I have no clue where to start.

Also, just to clarify—the Revels had poor bass when placed as in arrangement 1 perhaps due to little room gain. They are now in the same position as the B&Ws were (as shown in arrangement plan 2 above), where wall reflectivity has helped improve the bass significantly. However, the highs are quite intense, so I’m planning to install some absorbers.

 

[DanielT]

An iPhone with the NIOSH app will work just fine. This is more of a practical reality check since OP mentioned a lack of bass. "Fun" might be a stretch, especially if it involves moving heavy speakers -I probably wouldn't bother myself. Well, maybe, if I really thought something was off. Money spent should always bring an upgrade. -Says the penny-pincher.

For a basic check, what you say seems like a sensible approach.

Thank you all very much for your kind help-I truly appreciate it.

Let’s say I can arrange the speakers so their positions are nearly identical. By the way, thanks to the cones, the Salon 2s are easier to reposition than the 683s, which weigh about 70 lbs, if I remember correctly. What app should I use to record the songs and check the C-weighted peaks, as per Brad's suggestion? I’m really a novice when it comes to testing and measurement, so I have no clue where to start.

Also, just to clarify—the Revels had poor bass when placed as in arrangement 1 perhaps due to little room gain. They are now in the same position as the B&Ws were (as shown in arrangement plan 2 above), where wall reflectivity has helped improve the bass significantly. However, the highs are quite intense, so I’m planning to install some absorbers.

You can measure and check how the room affects bass FR. Then you can EQ according to your taste.

However, the highs are quite intense, so I’m planning to install some absorbers.

Have you tried this:

The measurements taken to generate fig.4 were taken with the Salon2's five-position Tweeter Level switch set to its central, "0dB" position. Fig.5 shows the effect on the Revel's tweeter-axis response when this switch is set to its maximum +1dB and –1dB positions. The Salon2's output in the top two audio octaves is hinged up or down by up to 1.6dB.

Revel Ultima Salon2 loudspeaker Measurements

Sidebar 3: Measurements My estimate of the Revel Ultima Salon2's voltage sensitivity was 86dB(B)/2.83V/m. This is slightly lower than the specified 86.4dB but within experimental error of that figure. The speaker's impedance (fig.1) drops to between 3 and 5 ohms between 17Hz and 600Hz, but as...

www.stereophile.com

In addition, your NAD C375BEE has a treble tone control. Try and turn it down a bit. Such tone controls often starts to have an effect quite far down in frequency. It can look like this:

I don't know if it will be exactly or fairly similar to the graph above with your NAD amp.That depends on how the tone control is designed, but you can at least test it by turning the tone control.

Tone control

I'm new around here & realize that even with the science there's still opinions on it ! Which makes for some great reading ;) I'm buying a new amp 1.5K-2K budget for music only and there is always a compromise at this price point. But the one thing I would not compromise on is tone control. (I'm...

audiosciencereview.com

Then we have custom PEQ that you can create but I'll leave that aside, regarding what you experience with the highs. Bass, where the room affects the FR, always does well with tailor-made EQ, however.

 

[Nothingness]

We've had the Salon 2s for about a month now. I’ve added several absorbers to the back wall and the ceiling to reduce the harsh treble reflections from a wall that’s about two to two and a half feet behind my listening chair. My wife’s been enjoying them more and more—she really loves the level of detail. One of her favorites is Spice Girls' Viva Forever, especially when the sound moves from right to left.

Personally, I can’t pick up differences very well in the 4k–7kHz range due to my tinnitus unless I crank the volume up to around 80dB, which I don’t enjoy. I’ve realized my comfortable listening level is more in the 60–70dB range. I’m getting more familiar with the bass too—I'd say it's moderate, but that might be due to my room’s poor acoustics. The L-shape probably causes some bass loss. I really believe the room is the most important part of any setup.

I also picked up another pair of Revels—this time the F206s—for a dedicated room at my parents’ house in another city. The dealer was closing for renovations, so I got them brand new at a very great price. I only visit a few days every couple of months, so I didn’t need anything too fancy.

Now I have the opposite issue. I tested the setup using the WiiM's room correction feature and got a clear bass peak at 50Hz. My old 20-year-old B&W 603 S2s showed the same peak (with worse dips and spikes), so I guess the room has strong gain at that frequency, causing boomy bass. Turns out my huge bookshelf isn’t enough for low-end absorption—I still have too many hard surfaces from the walls and floors. I’m leaving it for now until I have more time to deal with it when I’m back there.

It looks completely different in my room from Amir's review:

I think I really enjoy the Revels—but I enjoy them even more because I got such great deals. Maybe it’s just me, but I probably have a bit of an obsession with value.

I auditioned several other high-end speakers to get a sense of how my Salon 2s stack up. I tried the KEF Blade Two Metas, but in the dealer’s room, the bass actually felt weaker than what I get from my Salons in my room. I’m guessing that was mostly due to his room acoustics. He also had some insanely expensive speakers—seven-figure range—but I didn’t catch the name.

I’ll probably bring my wife to audition another pair of the Blades, just for fun. I have no intention of changing or upgrading gear—it’s just that she has better ears than I do.

Thanks again, Brad, for introducing me to Sonic Visualizer—I was almost able to replicate your graph. I gave ChatGPT a pretty hard time in the process, but that AI really is an amazing tool!

 

[Old_School_Brad]

Thanks for the update! And yes -the room defines both the highs through reflections and the lows through its dimensions.

 

[denydog]

I wish I'd noticed this thread when it started because I used a NAD C375 BEE integrated, and later a power amp version of the C375 (C275) with Revel F208s for ten years. . The C375, and C275 worked great with the 208s. I had no complaints. Sounded great, and never ran out of steam.

But I should also mention that I bypassed the pre amp of the C375 with various stand alone pre amps a while back because I think the pre of the C375 is the weaker half.compared to the power output section.

I don't pay much attention to NAD's IHF power ratings as I consider them more a marketing thing. I don't think it's as useful for comparisons.

Also the C375 etc are a little unusual in specifying the same 150 watts output at 4 and 8 ohms. My understanding is they use dual power rails. Higher voltage rail for easier speaker loads, then switching to lower voltage rail when impedance drops. This helps keep the amp from overheating under difficult conditions.

FYI, I also still use a NAD C372 Integrated in my TV Room

Curiosity finally got the best of me a year or so ago and I moved on to a pair of Benchmark AHB2 Power Amps. I thought there was a slight increase in sound quality with the Benchmarks, but I think it's just as possible that it was my imagination.

Congratulations and good luck with the Solon2s.

 

[Nothingness]

The thread originally began with the question: “Can my NAD C375BEE drive a pair of Revel F208s?” As things progressed, it turned into: “Can my NAD C375BEE drive a pair of Revel Salon 2s?”

At its core, the real question was: “Can a lower-powered amp properly drive a more power-hungry speaker?” I asked because I’d often heard that lower-powered amps can’t drive certain speakers to their full potential—especially when it comes to bass control.

Thanks to the thoughtful and informative responses from members here (truly, I appreciate your time), my main takeaways were:

1. Yes, it can. A watt is a watt. There’s no difference between a powerful amp putting out 50W and a lower-powered amp putting out the same 50W. What matters is whether the amp can deliver enough clean power for your specific listening needs.

2. Speaker wattage ratings are just about meaningless. It's complicated and not easy at all to assign simple numbers for min or max power. It depends on the content being played (the frequency, the duration). The maximum values they list are often well more than enough to fry the speakers.

Now, as I continued reading through the forum, I noticed that questions similar to mine come up repeatedly. So here’s a follow-up question—maybe a silly one, but I’m genuinely curious (and feel free to point it out if it’s inaccurate):

Let’s say the frequency response chart of the Salon 2 shown here is exactly what I get in my room. Now imagine I turn down the amp’s volume by 5dB. Does that reduction apply uniformly across all frequencies? In other words, would the output at 100Hz drop by 5dB, and so would the output at 1kHz, and so on? Or does it behave differently depending on the frequency?

I wish I'd noticed this thread when it started because I used a NAD C375 BEE integrated, and later a power amp version of the C375 (C275) with Revel F208s for ten years. . The C375, and C275 worked great with the 208s. I had no complaints. Sounded great, and never ran out of steam.

But I should also mention that I bypassed the pre amp of the C375 with various stand alone pre amps a while back because I think the pre of the C375 is the weaker half.compared to the power output section.

I don't pay much attention to NAD's IHF power ratings as I consider them more a marketing thing. I don't think it's as useful for comparisons.

Also the C375 etc are a little unusual in specifying the same 150 watts output at 4 and 8 ohms. My understanding is they use dual power rails. Higher voltage rail for easier speaker loads, then switching to lower voltage rail when impedance drops. This helps keep the amp from overheating under difficult conditions.

FYI, I also still use a NAD C372 Integrated in my TV Room

Curiosity finally got the best of me a year or so ago and I moved on to a pair of Benchmark AHB2 Power Amps. I thought there was a slight increase in sound quality with the Benchmarks, but I think it's just as possible that it was my imagination.

Congratulations and good luck with the Solon2s.

Thanks, denydog, for your kind words—and congrats on the Benchmark AHB2 power amps! I remember from Amir’s measurements that your amp ranks near the top. While there aren’t measurements for the older NAD C375BEE, I’d imagine the Benchmark is a clear step up, so you’ll likely notice an improvement.

Yes, I noticed the oddly identical power ratings at 4 ohms and 8 ohms on the NAD as well. (By the way, I also use a smaller NAD C352 to drive my other pair of Revel F206s.)

I’m personally quite happy with my NAD C375BEE. I’m just not sure how audible the difference would be for me if I upgraded. Maybe my wife could tell—but I probably wouldn’t!

 

[Old_School_Brad]

View attachment 448033

Let’s say the frequency response chart of the Salon 2 shown here is exactly what I get in my room. Now imagine I turn down the amp’s volume by 5dB. Does that reduction apply uniformly across all frequencies? In other words, would the output at 100Hz drop by 5dB, and so would the output at 1kHz, and so on? Or does it behave differently depending on the frequency?

The response will be the exact same, just at lower SPL. Imagine the pictured trace as being drawn at a lower point on the Y-axis.

Turning up the volume will eventually introduce some non-linear effects, known as compression, but that's a slightly different topic than what you're asking about.

 

[DanielT]

Plus, if we continue on the theme of a slightly different topic than what you're asking about. I can mention that FR itself does not change BUT how you experience sounds at different sound levels does:

The Fletcher Munson Curve contains a set of graphs that show that when you listen to music at a lower volume, mid-range frequencies will be sound more prominent, whereas high and low frequencies will be somewhat suppressed.

However, when the volume is increased, the reverse happens – high and low frequencies become more pronounced while the mid-range frequencies fade into the background.

Should you use Fletcher-Munson loudness compensation?

I know many are familiar with the Fletcher-Munson or equal loudness curves. In a nutshell: “The Fletcher Munson Curve contains a set of graphs that show that when you listen to music at a lower volume, mid-range frequencies will be sound more prominent, whereas high and low frequencies will be...

audiosciencereview.com

 

[denydog]

Thanks, denydog, for your kind words—and congrats on the Benchmark AHB2 power amps! I remember from Amir’s measurements that your amp ranks near the top. While there aren’t measurements for the older NAD C375BEE, I’d imagine the Benchmark is a clear step up, so you’ll likely notice an improvement.

Nothingness-
FYI, I don't know if you've seen these measurements of the C275 power amp which is same design as power amp in the C375.


BHK Lab Measurements: NAD C275