Hypex NC252MP or NC502MP as external amps for Denon X4800H in a small room?

[PHD]

Hi. I need help making the right decision.

My room is quite small 3m by 4 m but I sit 2.5m away from the front stage. I already have dual Hypex NC400 amps for the fronts, which I plan to use for the surrounds. My X4800H is going to be installed inside a closed cabinet so I want to use external amplification for the left, right, center, surrounds, and single surround back in a 6.2.4 setup. So the X4800H will only power 4 atmos speakers.


My speakers are all Focal Aria. 2 pairs of Aria 906 (front and surrounds) and two Aria CC900 centers (front and back centers).

I sit 1.5 meters away from each surround speaker, 1 meter away from the back center, and 2.5m away from each front speaker.
I want to add a 4-channel Buckeye amp, and I can't decide if the NC252MP or the NC502MP is the better choice because I may not need such high power (Arias have about 87dB-88dB of sensitivity). But I do want the amps to be an upgrade for the X4800H internal amps.

Denon AVR-X4800H AVR Review

This is a review and detailed measurements of the Denon AVR-X4800H 9.4 home theater receiver. It was kindly drop shipped by a member and costs US $2499. While the look is the same as previous generations, the feel of the control knobs is much improved which I appreciate. Menu system is also...

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Buckeye NC252MP Stereo Amplifier Review

This is a review and detailed measurements of the Buckeye NC252MP balanced stereo class D amplifier. It was kindly drop shipped to me by a member and costs US $575. The amp is almost the size of a loaf of bread and literally weighs nearly as much! Amazing how far amplification technology has...

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Buckeye Nc502mp Review (6 Channel Amplifer)

This is a review and detailed measurements of the Buckeye Hypex NC502MP based, 6-channel amplifier. It was kindly purchased and drop shipped to me by our dear moderator, @AdamG247. I don't know what it costs. Not sure what there is to say about the case: Or the back panel: Other than...

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Would there be any improvement over the X4800H if I go with the NC252MP? Do I need the NC502MP or could I settle for the NC252MP and save $200?

@Buckeye Amps

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

Currently, the internal amps of the X4800H, as well as the Hypex NC400, seem to have plenty of power for my needs (96dB SPL at MLP is the highest I ever go).

Thanks

 

[Mort]

Both will be upgrades.

The 252 has a lower input sensitivity so you will get the entire 250w, the 500 needs more than the x4800h can put out so you won't get the whole 500w.

I have an x4800h with a 6ch 500 buckeye amp in a small room. I don't really need that much power but that did not deter me from getting the nc500mp in a similar situation.

I realized that I had $10,000 in speakers and I did not want to save $200, I'd rather have the headroom. I also think the 500s will have better resale value.

I would sell the 400s and buy a 6ch 500 buckeye amp.

 

[SIY]

Currently, the internal amos of the X4800H, as well as the Hypex NC400, seem to have plenty of power for my needs

Then what are you trying to achieve, beyond buying shiny new gear?

 

[PHD]

Then what are you trying to achieve, beyond buying shiny new gear?

The X4800H is sitting outside the cabinet but will soon go inside to make space for my new Turntable. It's a very small cabinet without any vent openings. A clearance of about 1 inch above the top cover of the AVR inside a closed space. Heat is going to be a major factor.

 

[SIY]

The X4800H is sitting outside the cabinet but will soon go inside to make space for my new Turntable. It's a very small cabinet without any vent openings. A clearance of about 1 inch above the top cover of the AVR inside a closed space. Heat is going to be a major factor.

Fair enough, but you'll be spending a lot more money than if you just ventilated the cabinet or put in a whisper fan. Or tried it as-is and see what the temperatures actually are. If the heatsinks don't get warmer in there than, say, 60°C (which is for humans pretty hot), the receiver will be fine. If the temps do rise above that, it's your call about dropping four figures on new amps.

Note that the amp gains are adjustable by moving some jumpers on the boards.

 

[PHD]

Both will be upgrades.

The 252 has a lower input sensitivity so you will get the entire 250w, the 500 needs more than the x4800h can put out so you won't get the whole 500w.

I have an x4800h with a 6ch 500 buckeye amp in a small room. I don't really need that much power but that did not deter me from getting the nc500mp in a similar situation.

I realized that I had $10,000 in speakers and I did not want to save $200, I'd rather have the headroom. I also think the 500s will have better resale value.

I would sell the 400s and buy a 6ch 500 buckeye amp.

Thanks for the info. Regarding the input sensitivity, it seems like a 3 to 4dB difference. What if after Audyssey calibration, I boost all channel levels by +4dB (post calibration average leaves plenty of headroom)? Wouldn't that compensate for the difference and allow the NC502MP to reach higher power? Actualy, if it's input sensibility is lower, the Audyssey calibration should end up with higher channel levels to reach the reference level anyways, isn't that right?

Also, I will be using RCA to XLR cable which would cost 6dB in gain.



Thanks

 

[Mort]

Thanks for the info. Regarding the input sensitivity, it seems like a 3 to 4dB difference. What if after Audyssey calibration, I boost all channel levels by +4dB (post calibration average leaves plenty of headroom)? Wouldn't that compensate for the difference and allow the NC502MP to reach higher power? Actualy, if it's input sensibility is lower, the Audyssey calibration should end up with higher channel levels to reach the reference level anyways, isn't that right?

Thanks

Im sure someone will do the calculations faster and more accurately than me. It's not a huge amount, no and it only affects your top volume. Since you don't really need more power, you will not notice.

I don't think anything in eq can make up for a lower than desired input voltage.

 

[PHD]

Im sure someone will do the calculations faster and more accurately than me. It's not a huge amount, no and it only affects your top volume. Since you don't really need more power, you will not notice.

I don't think anything in eq can make up for a lower than desired input voltage.

Not in EQ, I meant, that after Audyssey finishes calibration, channel levels are set between -3dB and +4dB, which leaves plenty of headroom to add, say +6dB to all channels, thus doubling the output level.

 

[Mort]

Not in EQ, I meant, after Audyssey finishes calibration. channels levels are set between -3dB and +4dB, wich leaves plenty of headroom to add, say +6dB to all channels, thus doubling the output level.

Yes but I don't think this is an argument for the 252. You could do this with either amp. I don't see how that makes one better than the other.

The point is you have more than enough power with either choice, so yes you can adjust quite a bit with the 252 and more with the 500.

The point about input sensitivity is just a technical optimization difference.

 

[Matias]

For surrounds the 252 is more then enough.

 

[PHD]

I was thinking of using it for the fronts and using the old NC400 for the surrounds or for the front/back center channels.

 

[Matias]

I would (and did) leave the higher power modules for the front trio and leave the 252 for surrounds. Simply because of higher power is more needed in the fronts on all contents.

 

[Sokel]

Whatever choice you'll do the sound won't change with a sane arrangement.
NC400 and NC252 won't have any difference in SQ (my opinion is that NC400 is a better amp than NC252 but that is just weirdo me )

All you need to take care is nice gain structure based on the specs and a little measurements.

 

[CapMan]

Then what are you trying to achieve, beyond buying shiny new gear?

I was just going through the same mental process as the OP - that perhaps external amps would be 'better' than those in my X4800.

Many thanks @SIY for your timely post which has pulled me back into the land of objective reality

This is the reason I LOVE this forum ! So many £s saved !

 

[Mort]

I was just going through the same mental process as the OP - that perhaps external amps would be 'better' than those in my X4800.

Many thanks @SIY for your timely post which has pulled me back into the land of objective reality

This is the reason I LOVE this forum ! So many £s saved !

Exactly. It won't be better audio.

On the other hand, I just bought the nc500mp in a similar circumstance because it was only $200 more and I thought it might be useful in the future or at least retain a good chunk of resale value. And I like the engineering even if I can't hear it in my circumstance right now.

 

[Zwepp]

I would definitely try to find some other way for you to integrate a turntable into your system, instead of cramming your AVR into a tiny space like you described. Even as a pre-amp it still needs some room to breathe. The HDMI board will dissipate quite some heat as well. With more room to breathe, the X4800H will do fine on its own with your speakers and room dimensions.

 

[alvigg]

I have a 7.4.6 system with Buckeye's. I opted for the 252's for the 8 surround channels and that works fine. For the fronts, I use the purifi amps. It was a big improvement over my ATI system and one I can manage as I get older.

 

[dfiler]

In a small room with those speakers, the 252 is more than enough. I have a mix of 252 and 502 and wish i'd got all 252 for surrounds and heights. In my open-plan house, more headroom was debatable for the LCR channels. But otherwise, the 252 is preferable. It has identical sound but consumes less power and generates less heat. These amps are efficient at high output but the baseline power consumption is not trivial. The 502 runs noticeably hotter than the 252.

 

[EasyC]

The X4800H is sitting outside the cabinet but will soon go inside to make space for my new Turntable. It's a very small cabinet without any vent openings. A clearance of about 1 inch above the top cover of the AVR inside a closed space. Heat is going to be a major factor.

My 3800 is also in a narrow cabinet. I did make a hole in the back, but put two of these fans with a controller on top of the AVR:

https://www.amazon.com/dp/B012CL2V3I?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Works great.