Denon AVC-X4800H and Focal Kanta - clipping ?

[LeGratteOreilles]

Hello,

I have a Denon AVC‑X4800H driving a Kanta Center, 2 Kanta 2 for L/R, and 2 Aria Evo X1 for surround.

I have a crossover at 60 Hz on the Aria and the Center, SVS SB‑5000 down to 40 Hz, and Kanta 2 at 40 Hz.

I have some doubts because I switched the amplifier to 4 ohm mode, and I’m not sure if that’s a good idea.

Setting the A/V Receiver Impedance Selector Switch

This article explores the purpose and function of the impedance switch found on some A/V receivers. Tradeoffs of following manufacturers recommended settings are also discussed. YouTube video inside.

www.audioholics.com

My amplifier has gone into protection several times, even though I’m only at 70 dB at the listening position (3 m away, -20 dB main volume, and Audyssey Reference set the Kanta 2 and C to around -4.5 dB, Aria -2dB).

I believe the Kanta 2 dip to 2.97 ohms around 105 Hz, and the Aria Evo X1 down to 4.6 ohms around 100 Hz?

Am I at risk of damaging the tweeters of the speakers?
Also Audyssey told me the wiring of my Kanta was wrong and detected an issue with the phase. But I checked and it looks normal. Red on red black on black.

I’m considering buying a Purifi amp to put on the Denon pre-outs for the 3 Kanta speakers to avoid clipping.

But I’m not sure if the Denon can handle the Aria Evo X1. It’s the most expensive purchase I ever made and I’m afraid of damaging something.

Any advice would be greatly appreciated.

 

[dlaloum]

First off its best to leave the AVR at the default setting, and not the 4 ohm setting.

Secondly, the X4800 is quite capable, however when you put a low impedance reactive load on it, you probably will be constrained to around 30W@2ohm, a bit more at 4 ohm and 8ohm.

Although I have not seen that type of lab test for the X4800 (amirm added it after he had tested the X4800) - it's near cousin the Marantz Cinema 40 was tested:

'Marantz Cinema 40 AVR Review'

Dec 19, 2023

This is a review and detailed measurements of the Marantz Cinema 40 9.4 channel AV Receiver (AVR). It is on kind loan from a member and costs US $3,500.

As is typical in this class, you get a very large box. At least the look is unique and to my liking. The port hole display while limiting fits in the style.

Back panel as usual has hundreds of connections:

While I liked the remote on Marantz AV 10 I reviewed recently, in this instance had rather sticking and hard to use 4-way arrow buttons. I updated the unit to latest firmware and performed a factory...

• amirm
• Replies: 264
• Forum: Home Theater AVR and Processor Review

• 

I would expect that other than the HDAM's rather than IC's the amps in the X4800 and cinema 40 are likely very similar... (photos of their interior shows them to be well nigh identical!).

So you can base your estimations on a reality of 30W clean power.

If that isn't enough, then you will indeed need external amps - I too have hard to drive low impedance/reactive speakers - and I organised beefy external amps to handle that - and it did make an audible difference, however, checking how much power I actually use, I tend to max out at peaks of around 16W.... so the 30W might well be ample!

In any case, if you can borrow a beefy amp to try out, you could see whether it has an audible impact in your setup.

The other thing that will happen, is once you take that load off the AVR, it will have more power supply current to provide for the other channels - so it tends to be a win - win.... your mains get the benefit of their own amp, and every other channel gets a boost as well!

 

[kyuu]

First off its best to leave the AVR at the default setting, and not the 4 ohm setting.

Secondly, the X4800 is quite capable, however when you put a low impedance reactive load on it, you probably will be constrained to around 30W@2ohm, a bit more at 4 ohm and 8ohm.

Although I have not seen that type of lab test for the X4800 (amirm added it after he had tested the X4800) - it's near cousin the Marantz Cinema 40 was tested:

'Marantz Cinema 40 AVR Review'

Dec 19, 2023

This is a review and detailed measurements of the Marantz Cinema 40 9.4 channel AV Receiver (AVR). It is on kind loan from a member and costs US $3,500.

As is typical in this class, you get a very large box. At least the look is unique and to my liking. The port hole display while limiting fits in the style.

Back panel as usual has hundreds of connections:

While I liked the remote on Marantz AV 10 I reviewed recently, in this instance had rather sticking and hard to use 4-way arrow buttons. I updated the unit to latest firmware and performed a factory...

• amirm
• Replies: 264
• Forum: Home Theater AVR and Processor Review

• 

View attachment 476331

I would expect that other than the HDAM's rather than IC's the amps in the X4800 and cinema 40 are likely very similar... (photos of their interior shows them to be well nigh identical!).

So you can base your estimations on a reality of 30W clean power.

If that isn't enough, then you will indeed need external amps - I too have hard to drive low impedance/reactive speakers - and I organised beefy external amps to handle that - and it did make an audible difference, however, checking how much power I actually use, I tend to max out at peaks of around 16W.... so the 30W might well be ample!

In any case, if you can borrow a beefy amp to try out, you could see whether it has an audible impact in your setup.

The other thing that will happen, is once you take that load off the AVR, it will have more power supply current to provide for the other channels - so it tends to be a win - win.... your mains get the benefit of their own amp, and every other channel gets a boost as well!

Er, I believe in that graph you posted the Y-axis is volts, not watts. The relevant graph for watts would be this one:

Don't think you'll be power-limited at low impedance.

@LeGratteOreilles Definitely do not use the 4-ohm impedance setting of the AVR, as stated. All that does is power-limit you for no benefit. Use the default "8 ohm" setting regardless of the load.

 

[dlaloum]

Er, I believe in that graph you posted the Y-axis is volts, not watts. The relevant graph for watts would be this one:

Don't think you'll be power-limited at low impedance.

@LeGratteOreilles Definitely do not use the 4-ohm impedance setting of the AVR, as stated. All that does is power-limit you for no benefit. Use the default "8 ohm" setting regardless of the load.

Yes - thank you for the correction!

 

[LeGratteOreilles]

Thanks a lot guys

I put it back to 8 ohms. A Denon rep told me to try 6 ohms but I’ll keep it at 8.
I did some tests and I listened for 2 hours with the 5 speakers playing music on multi channel stereo.
I had some audible clipping from the Kanta Tweeters on Dire Straits - Sultans of swing live and I really don’t know why since the power and headroom should be enough. I was listening at -25dB and the amp was reasonably warm.

I tried again a few minutes later with the same song and it was okay. I really have no clue.

I think I’ll add a Purify amp for the 3 Kantas.

 

[Svend P]

If you are on a budget, I use a Fosi V3 with my 4800H. With the big power supply, it offers 141 W in 4 ohm

'Fosi Audio V3 Amplifier Review'

Jun 20, 2023

This is a review and detailed measurements of the Fosi Audio V3 stereo amplifier. It was sent to me by the company and costs US $89.99 with stock 32 volt supply. Price goes up to $109.99 with the 48 volt supply. There is a $10 discount coupon right now.

Despite its budget price, the V3 manages to look elegant with the hole pattern on top and large and smooth feeling Volume/On/Off control. Power supply is external and as noted, you get a choice:

As you will see later, you really want the 48 volt version:

Yes, it is a larger supply but you are going...

• amirm
• Replies: 3,160
• Forum: Stereo and Multichannel Amplifier Reviews

• 

 

[vicenzo_del_paris]

I also have Kanta 2s and center.
I drive them with NCx500 modules (Boxem A 5519/N3 power amp).
FWIW, Never experienced clipping, nor module shutdown.
Even at -5 db.
SVS subs doing the low end (whatever different XOs tried over time from 40 to 80hz).