Looking for suggestions to amplify B&W 802 D3

[AirCooled32]

Hello everyone,

I would like some help on deciding on an amplifier to power my recent acquisition of floor standing Bowers & Wilkins 802 D3. They're currently being powered by Buckeye's 3ch Puifi 1ET400A amp (225w peak @ 8ohms) which is fed by a Denon X4700h AVR. The sound at lower - medium listening levels I feel the amp preforms flawlessly, but when volume is further increased I can hear the music start to become attenuated and flat. According to B&W, the speakers would like to see a power rating of 50-500w from the amplifier. I was looking into Buckeye's Hypex NCx500 which offers 380wpc @ 8ohm (peak), but that falls short from the speaker's max potential of 500 watts.

If it matters I'm about 8' away from the speakers in a 16'w x 14'L room.

Suggestions would be greatly appreciated, thank you.

 

[AdamG]

The Ncore NC502MP amps should work fine. If you want to stick with Buckeye amps.

Buckeye Amps: New US based Hypex multichannel amplifier builder, line-up announcement!

Hypex NC502MP specs: - 450w @ 2ohm (per channel, peak) - 500w @ 4ohm (per channel, peak) - 350w @ 8ohm (per channel, peak) Hypex NC252MP specs: - 180w @ 2ohm (per channel, peak) - 250w @ 4ohm (per channel, peak) - 150w @ 8ohm (per channel, peak) PRICING: XL 8ch Aluminum Case (17"x13"x6")...

www.audiosciencereview.com

Buckeye NC502MP 8-Channel Amp Review

This is a review and detailed measurements of the Buckeye Hypex NC502MP 8-channel class D amplifier. It was sent to me by the company and costs US $2,295. There is not a whole lot to look at here. Sheet metal is rather thin and fitment not that great. So put it in a cabinet and forget about...

www.audiosciencereview.com

 

[JustJones]

The NCx500 should be fine if for some reason you just want an amp that meets or exceed the 500 watts you could try This. Those speakers are a little demanding under 1000hz.

Bowers & Wilkins 802 D3 Diamond loudspeaker Measurements

Sidebar 3: Measurements

www.stereophile.com

 

[DVDdoug]

A power factor of two is only 3dB and going from 225W to 500W only get 3.5dB louder.

3dB is a "noticeable" difference but if you are listening today and then listening 3dB louder or quieter tomorrow you might not notice the difference. And some songs/music might be peaking at 225W and others at 100W or "needing" 500W, etc. Perceived loudness doesn't correlate well with peak levels... Loudness is more related to the average level (or "density") and the frequency content.

but when volume is further increased I can hear the music start to become attenuated and flat.

That may not be the amplifier. It could be the speakers or just your perception... If you overdrive the amp you'll get clipping/distortion and maybe a "harsh" sound. Clipping is a (bad) kind of dynamic compression but usually it's heard as "distortion". And you might not even hear distortion with 3dB of clipping on occasional peaks.

 

[LTig]

Hello everyone,

I would like some help on deciding on an amplifier to power my recent acquisition of floor standing Bowers & Wilkins 802 D3. They're currently being powered by Buckeye's 3ch Puifi 1ET400A amp (225w peak @ 8ohms) which is fed by a Denon X4700h AVR. The sound at lower - medium listening levels I feel the amp preforms flawlessly, but when volume is further increased I can hear the music start to become attenuated and flat.

This sounds like (power) compression of the drivers. More power from the amp won't fix it. If you need to play that loud you need other speakers.

 

[LTig]

Do you know what levels you are listening at? Also, what size is the room and how far are you from the speakers?

The OP wrote: "If it matters I'm about 8' away from the speakers in a 16'w x 14'L room."

 

[MaxwellsEq]

The OP wrote: "If it matters I'm about 8' away from the speakers in a 16'w x 14'L room."

Duh - sorry!

 

[AirCooled32]

The Ncore NC502MP amps should work fine. If you want to stick with Buckeye amps.

Buckeye Amps: New US based Hypex multichannel amplifier builder, line-up announcement!

Hypex NC502MP specs: - 450w @ 2ohm (per channel, peak) - 500w @ 4ohm (per channel, peak) - 350w @ 8ohm (per channel, peak) Hypex NC252MP specs: - 180w @ 2ohm (per channel, peak) - 250w @ 4ohm (per channel, peak) - 150w @ 8ohm (per channel, peak) PRICING: XL 8ch Aluminum Case (17"x13"x6")...

www.audiosciencereview.com

Buckeye NC502MP 8-Channel Amp Review

This is a review and detailed measurements of the Buckeye Hypex NC502MP 8-channel class D amplifier. It was sent to me by the company and costs US $2,295. There is not a whole lot to look at here. Sheet metal is rather thin and fitment not that great. So put it in a cabinet and forget about...

www.audiosciencereview.com

Thank you for the suggestion. After reading @DVDdoug , I feel I need to investigate my situation further.

The NCx500 should be fine if for some reason you just want an amp that meets or exceed the 500 watts you could try This. Those speakers are a little demanding under 1000hz.

Bowers & Wilkins 802 D3 Diamond loudspeaker Measurements

Sidebar 3: Measurements

www.stereophile.com

A power factor of two is only 3dB and going from 225W to 500W only get 3.5dB louder.

3dB is a "noticeable" difference but if you are listening today and then listening 3dB louder or quieter tomorrow you might not notice the difference. And some songs/music might be peaking at 225W and others at 100W or "needing" 500W, etc. Perceived loudness doesn't correlate well with peak levels... Loudness is more related to the average level (or "density") and the frequency content.


That may not be the amplifier. It could be the speakers or just your perception... If you overdrive the amp you'll get clipping/distortion and maybe a "harsh" sound. Clipping is a (bad) kind of dynamic compression but usually it's heard as "distortion". And you might not even hear distortion with 3dB of clipping on occasional peaks.

Thank you for the incredible informative post. I haven't experience any clipping or distortion while listening and I'm not listening at "crazy" loud listening levels either. It could absolutely be total user error toying with Audyssey's MultEQ-X when I don't have much of a clue of what I'm doing. I'll start by removing my "corrections" and go from there.

This sounds like (power) compression of the drivers. More power from the amp won't fix it. If you need to play that loud you need other speakers.

The ratings of the drivers are nearly 2x the amp's capability, so I wouldn't think they're being overdriven. I'm wouldn't be surprised if this is the wrong way of looking it.

Do you know what levels you are listening at? Also, what size is the room and how far are you from the speakers?

On the Denon app, I think it says 74db? I could be way off on this number. The room is 16wx14lx8h

 

[MaxwellsEq]

On the Denon app, I think it says 74db? I could be way off on this number. The room is 16wx14lx8h

74dB is not a silly level. It's a good-ish level to sound energetic without thrashing anything. At that level, I would be surprised if the amp is running out of steam. Do you find it starts out with more energy but gradually get's less exciting the longer you listen?

 

[AirCooled32]

74dB is not a silly level. It's a good-ish level to sound energetic without thrashing anything. At that level, I would be surprised if the amp is running out of steam. Do you find it starts out with more energy but gradually get's less exciting the longer you listen?

I usually start off much lower than 74db, and will gradually increase the volume as my ears acclimate. Once I start pushing into the mid 70 dbs, I'll start to notice the lack of steam from the speakers as you've mentioned. I think I see where you're headed with this (heat). Once I get home and settle in, I'll "push" the amps while they're cold to where I know they start to struggle. If I can operate them for 10 minutes or so without any give, I add some type of air circulation to them.

 

[MaxwellsEq]

I usually start off much lower than 74db, and will gradually increase the volume as my ears acclimate. Once I start pushing into the mid 70 dbs, I'll start to notice the lack of steam from the speakers as you've mentioned. I think I see where you're headed with this (heat). Once I get home and settle in, I'll "push" the amps while they're cold to where I know they start to struggle. If I can operate them for 10 minutes or so without any give, I add some type of air circulation to them.

That was what I wondered. I have heard of speakers that struggle when voice coils and crossover components get warm. It's impossible for any of us to recreate your environment, of course, but my setup is calibrated at c 78dB which does sound quite loud enough to me. My amp is a Class AB nominally 50W (closer to 80W), but it certainly goes loud enough!

It's also worth noting that "500W" doesn't really mean very much. It certainly doesn't mean that you are missing out on very much. And as others have said, 380W is not much louder than 225W

 

[antcollinet]

I usually start off much lower than 74db, and will gradually increase the volume as my ears acclimate. Once I start pushing into the mid 70 dbs, I'll start to notice the lack of steam from the speakers as you've mentioned. I think I see where you're headed with this (heat). Once I get home and settle in, I'll "push" the amps while they're cold to where I know they start to struggle. If I can operate them for 10 minutes or so without any give, I add some type of air circulation to them.

Is that 74dB a measured level from a microphone? Or is it simply the indication on the volume control. If the latter it says nothing about the actual SPL you are listening to.


Also - what is the gain setting on the buckeye? If it is not high, then the denon will not be able to provide enogh voltage on the pre-outs to drive the amp to full power. You may even be clipping the pre-outs.

Even on high, it is marginal if the Denon can provide enough output voltage : Your speakers are 8ohm, so even on high gain, the buckeye needs 2.24V to deliver full power. I don't think the Denon will give this.

In particular, according to the review here - if you have the Denon internal amps still on, then the pre out will clip at 1.4V output, much lower than needed for the buckeye to deliver full power, and likely not any better with a different amp. So have you turned off the Denon internal amps?

This clipping could easily explain the reduction in quality you experience as you turn up the volume.

Denon AVR-X4700 AVR Review (Updated)

This is a second review of the Denon AVR-X4700 AVR. It was kindly purchased by a member and drop shipped to me. It costs US $1,700 from Amazon including free shipping. I will explain the reason for the revision in a bit. For now, I will cut and paste some of the information from the first...

www.audiosciencereview.com

With the AVR-X4700 (and all of 2020 series Denon AVRs) you can only turn off the amp for the front channels, or all the channels. If you want some other configuration, then you are dealing with amplifier clipping and lowering performance depending on how much you turn up the volume. To show this I measure at different output levels to identify the best performance:

As you see, the best performance is around 1.1 volts which produces over 100 dB SINAD (dashboard uses 2 volt output so gets lower SINAD). With the amp turned on, the highest you can go is 1.4 volts before clipping occurs and performance drops precipitously. So make sure to look up the specifications for your external amplifier to see what its "sensitivity" is that generates its maximum power. If it is below 1.4 volts, then you are good.

 

[AirCooled32]

Is that 74dB a measured level from a microphone? Or is it simply the indication on the volume control. If the latter it says nothing about the actual SPL you are listening to.


Also - what is the gain setting on the buckeye? If it is not high, then the denon will not be able to provide enogh voltage on the pre-outs to drive the amp to full power. You may even be clipping the pre-outs.

Even on high, it is marginal if the Denon can provide enough output voltage : Your speakers are 8ohm, so even on high gain, the buckeye needs 2.24V to deliver full power. I don't think the Denon will give this.

In particular, according to the review here - if you have the Denon internal amps still on, then the pre out will clip at 1.4V output, much lower than needed for the buckeye to deliver full power, and likely not any better with a different amp. So have you turned off the Denon internal amps?

This clipping could easily explain the reduction in quality you experience as you turn up the volume.

Denon AVR-X4700 AVR Review (Updated)

This is a second review of the Denon AVR-X4700 AVR. It was kindly purchased by a member and drop shipped to me. It costs US $1,700 from Amazon including free shipping. I will explain the reason for the revision in a bit. For now, I will cut and paste some of the information from the first...

www.audiosciencereview.com

The 74dB measurement was a guesstimate at best based on the Denon app.

On the Buckeye amp - all gains are set to "high".

The internal Denon amps are set to ON when I'm listening to anything other than 2ch mode. I haven't given 2ch much of a chance, but I'll explore it tonight to see how everything sounds.

Thank you for the Denon information and the difference it makes with the internal amps being on vs off. Thank you for giving me a reason to justify an 8 ch amp purchase to my wife, I'm sure she'll be pleased!

Also, a thank you to those who took their time to read and those who responded. This forum has been is amazing!

 

[antcollinet]

Thank you for the Denon information and the difference it makes with the internal amps being on vs off. Thank you for giving me a reason to justify an 8 ch amp purchase to my wife, I'm sure she'll be pleased!

She will when you tell her you need an 8 channel amp - but then "realise" you already have 3, so you only need 5 new ones.

 

[Beave]

Are you running 2 channel only or are other speakers involved?

Are you using a subwoofer or running them full range?

As an experiment, have you tried removing the Buckeye amp and powering the two B&W speakers directly from the Denon (try it with other speakers also disconnected)? That might help narrow down where the problem is (assuming there is one).

Those speakers have a really challenging load, in my estimation, based on JA's Stereophile measurements

https://www.stereophile.com/content/bowers-wilkins-802-d3-diamond-loudspeaker-measurements

Below 4 Ohms from about 70Hz to 1kHz and with a phase angle over -70 degrees at 50Hz.

 

[AirCooled32]

She will when you tell her you need an 8 channel amp - but then "realise" you already have 3, so you only need 5 new ones.

After about a half hour's worth of listening 2ch audio with the AVR set to "PRE", the richness of the audio has been restored! While I know it's not accurate, the Denon app estimated the dB to be about 68.

Do you think it would it make sense to keep the Puifi amp (225wpc peak) to power the LCR, and supplement it with a smaller Hypex (150wpc peak) for the surrounds? Or would I be better off purchasing a more powerful Buckeye Hypex NC502 amp (350wpc peak) to power it all?

Are you running 2 channel only or are other speakers involved?

Are you using a subwoofer or running them full range?

As an experiment, have you tried removing the Buckeye amp and powering the two B&W speakers directly from the Denon (try it with other speakers also disconnected)? That might help narrow down where the problem is (assuming there is one).

Those speakers have a really challenging load, in my estimation, based on JA's Stereophile measurements

https://www.stereophile.com/content/bowers-wilkins-802-d3-diamond-loudspeaker-measurements

View attachment 306205

Below 4 Ohms from about 70Hz to 1kHz and with a phase angle over -70 degrees at 50Hz.

Other speakers were definitely involved, and switching to 2ch has made all the difference! Thank you.

I am using a subwoofer, and the speakers are also set to full range. I haven't looked much into it, but I have heard suggestions to set large speakers to "small" before. I wonder if this the case that I may need to do that.

 

[antcollinet]

Are you running 2 channel only or are other speakers involved?

Are you using a subwoofer or running them full range?

As an experiment, have you tried removing the Buckeye amp and powering the two B&W speakers directly from the Denon (try it with other speakers also disconnected)? That might help narrow down where the problem is (assuming there is one).

Those speakers have a really challenging load, in my estimation, based on JA's Stereophile measurements

https://www.stereophile.com/content/bowers-wilkins-802-d3-diamond-loudspeaker-measurements

View attachment 306205

Below 4 Ohms from about 70Hz to 1kHz and with a phase angle over -70 degrees at 50Hz.

The Purify amp in use will stomp all over that impedance characteristic - so probably not an issue in this case.

 

[antcollinet]

After about a half hour's worth of listening 2ch audio with the AVR set to "PRE", the richness of the audio has been restored!

Well that's good news.

Do you think it would it make sense to keep the Puifi amp (225wpc peak) to power the LCR, and supplement it with a smaller Hypex (150wpc peak) for the surrounds?

That's what I'd do.

But if worried about the lower power for the surrounds, just get a two channel version of the higher power. Or even the two channel purify to match your LRC.

 

[MaxwellsEq]

After about a half hour's worth of listening 2ch audio with the AVR set to "PRE", the richness of the audio has been restored! While I know it's not accurate, the Denon app estimated the dB to be about 68.

Excellent news!