Best mid range receiver for 4 ohm towers?

j_garcia

j_garcia

Audioholic Jedi
When you say specs "way more than you need" I would always question that with 4 Ohm speakers. Unless the room is small, I would always opt for the most power you can reasonably afford for them. If these are the only 2 that are 4 Ohm, that is less of a risk.

109 dB reminds of the time I went to a concert with my wife. It was so extremely loud I had to use ear plugs.

Then I got out my iPhone's dB-meter app and measured the volume and it was about 107-109dB.

I could still hear the songs just fine even with both ear plugs tightly on. :D
I wear plugs at EVERY show now. I saw NIN in SF and even with plugs, my eardrums were still vibrating. Great show :D
 
Monitor Audioholic

Monitor Audioholic

Audioholic Intern
That's useful info, if your Denon would "cut out..", then you likely would have the same issue with the RZ50, based on bench test results. So, the AVR-X3800H is probably the better choice for you. You do have to pay for the Dirac Live license, but you can always try Audyssey and buy the $20 editor app that may give you satisfactory results. You indicated you wouldn't like to tweak, but we can help you tweak a few basic things that shouldn't take you an hour to accomplish.

Dirac Live does seem to go on sale (something like up to 30% discount) every few months, so keep that in mind.
You can't go wrong with the Denon, they are relatively bug free, plug it in and it will just work.

Don't worry about the high current talks, I have installed a 5.1 system with Monitor audio Silver 8 that should be very similar to your 8i, but strangely enough I think the 8i is actually an older model than the 8 that I installed brand new in 20156. Anyway, the mid range Marantz SR7009 had no problem driving them to insane levels in a large room at >4 meters, so your 3 m distance is not a problem.

"High current" is a relative term so Denon's claim of their AVRs being high current could be arguably true technically speaking anyway:). The important point is not to fixate on the high current buzz word, but consider how much current your speakers may need in your applications. That depends on you spl requirements and that is dependent heavily on your seating distance and the sensitivity of the speakers. Yours has sensitivity specs of 90 dB/w/m, that's reasonably high so that helps for sure.

If you are interested, you can estimate your speaker's need with an online calculator such as the following that has been linked about a million times on forums so it must easy to use.

Peak SPL Calculator (hometheaterengineering.com)
Btw, you're right about the 8i being the older model to the ones you fitted a while back.
I'm hoping that they'll come back to life with the new receiver, as I've had them for around 10yrs years and not really driven them at all.
 
lovinthehd

lovinthehd

Audioholic Jedi
Thanks Lovin'
So, that's a negligible loss right? I have never used the tuner in all the time I've owned my old Denon.
LOL haven't used a tuner for years myself, europe went to a different system than traditional broadcast radio so no need there. Even when I last lived in a big metro area, radio choices were slim, where am now almost non-existent as to what we can receive radio or tv (via repeater).
 
Monitor Audioholic

Monitor Audioholic

Audioholic Intern
Thanks Eppie
Good point about the hdmi version. I read a very positive review on here (link below) that there was a hdmi upgrade available when the X8500H was first released. Will check if the unit has had the upgrade before I commit, as I will also need to factor in the cost to do the upgrade.

4K should do me tbh.
I don't think I will miss HDR10+, as I've not heard of it until now? What does not having it mean in practice?

 
P

PENG

Audioholic Slumlord
Thanks Eppie
Good point about the hdmi version. I read a very positive review on here (link below) that there was a hdmi upgrade available when the X8500H was first released. Will check if the unit has had the upgrade before I commit, as I will also need to factor in the cost to do the upgrade.

4K should do me tbh.
I don't think I will miss HDR10+, as I've not heard of it until now? What does not having it mean in practice?

Unless you actually need it, there is no point paying $600. Same mentality may apply to buying a 7 years old flagship vs the high value X3800H that is still current in terms of features.
 
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AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
Same mentality may apply to buying a 7 years old flagship vs the high value X3800H that is still current in terms of features.
I agree. 7YR old AVR is a bit old for me. Considering that many people only buy AVR every 10-15 YR, might as well buy the latest model.
 
Monitor Audioholic

Monitor Audioholic

Audioholic Intern
Gotcha.
Thanks for setting me straight guys. Makes perfect sense. Seen a well priced X3800H but will have to factor in the additional cost for a DIRAC license. There's also an ex display Cinema 50, at an interesting price. Seems to have decent reviews.
 
D

dlaloum

Full Audioholic
Did you notice all the 4-ohm power output measurements in my AVR Spoiler? :D

Some people talk trash about AVRs, but many AVRs measure 200-300W x 2Ch into 4 ohms. :D
The issue usually happens with "nominally 4ohm" speakers - which means they average out to 4ohm

But the problems are the bits of the frequency range where they drop down below - or well below - 4ohm

My pair are 4ohm (nominal) with drops down to 3ohm and down to 1.6 ohm - my basic AVR seems to drive them OK - but the sound is not as good as I know it can be - Imaging is a bit off, midrange a bit confused / veiled... use my AVR's pre-out with an amp that can handle very low impedances (1ohm) - and the veil lifts, the imaging comes into focus....

Limits in low impedance handling are not obvious - there is no obvious distortion - I would love to know exactly what is happening in terms of distortion at the key low impedance frequencies - or perhas what happens in terms of distortion throughout the frequency range, when the amp needs to drive something at those key frequencies - cost something definitely happens!

This is why I am very keen on amps being measured at 2ohm as well as 4 and 8... (in a perfect world 1 ohm would be nice too!)
 
P

PENG

Audioholic Slumlord
Gotcha.
Thanks for setting me straight guys. Makes perfect sense. Seen a well priced X3800H but will have to factor in the additional cost for a DIRAC license. There's also an ex display Cinema 50, at an interesting price. Seems to have decent reviews.
I would suggest you buy the $20 MultEQ Editor app that may please you enough. If not then, wait for Dirac's 30% sale that will most likely be back soon enough and consider the lower priced 500 Hz limit instead of the full bandwidth version that cost much more.

Lots of people find room correction above even 300 Hz is not necessary, as the benefits of RC really help most in the bass range. In some cases, doing it for full bandwidth to 20,000 Hz may actually make things worse.

Lastly, all else being equal, it is better to get the Cinema 50 if price is the same or only slightly more but it would be silly to pay the list price difference of $800 to $1,000 in the US and Canada, when it is a fact that in Europe the price difference between the two has been only around $0 to $250. Unless the better look is worth that much to you.
 
Monitor Audioholic

Monitor Audioholic

Audioholic Intern
Thanks Peng! That's just what I wanna hear! Will save a tonne of money, which I can put towards something else. Like a CD player. My old Arcam Alpha 7SE jumps around and often doesn't even play the disc at all. So, I've been looking at replacing it with a classic Marantz CD6006. Although, a cheaper alternative wouldn't wouldn't go amiss if anyone can suggest one...
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
My pair are 4ohm (nominal) with drops down to 3ohm and down to 1.6 ohm…..use my AVR's pre-out with an amp that can handle very low impedances (1ohm)…

…This is why I am very keen on amps being measured at 2ohm…..
This reminds me of some time ago when a publication measured a bunch of amps down to 1-ohms. Many external amps and AVR did NOT pass the 1-ohm test.

High quality amps like ATI amps definitely passed. Even the 60WPC ATI amp passed the 1-ohm test on The Audio Critic.

But I do remember one of the AVRs that passed was a Denon AVR - I think it was one of the 3000-series Denon. So a Denon AVR passed this 1-ohm test when many external amps failed this test.

So the takeaway is that just because some cheaper amps and AVPs are “separates”, doesn’t mean they are even as good as some AVR.
 
P

PENG

Audioholic Slumlord
I agree. 7YR old AVR is a bit old for me. Considering that many people only buy AVR every 10-15 YR, might as well buy the latest model.
I tried explaining how AVRs works or not work with the so called 4 ohm nominal speakers, yes, including some that dips below such as his that has 1.6 ohm dip. He continued to choose to believe what he believes, that has a lot to do with his misconception, and that might have led to what he perceives when listening to those speakers. There is nothing you and I can post to convince him to consider other reasons why hear heard what he heard, so I gave up responding to those posts after responding, with explanation a few times. Other than that one, I do read and enjoy his many other posts and we agreed a lot more than we disagreed.:)

It is like someone who really believe they heard night and day difference between amps that have been measured and had not shown any scientific reasons to sound so different. Again, nothing we can do to convince, or even influence them lol..
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
I tried explaining how AVRs works or not work with the so called 4 ohm nominal speakers, yes, including some that dips below such as his that has 1.6 ohm dip. He continued to choose to believe what he believes, that has a lot to do with his misconception, and that might have led to what he perceives when listening to those speakers. There is nothing you and I can post to convince him to consider other reasons why hear heard what he heard, so I gave up responding to those posts after responding, with explanation a few times. Other than that one, I do read and enjoy his many other posts and we agreed a lot more than we disagreed.:)

It is like someone who really believe they heard night and day difference between amps that have been measured and had not shown any scientific reasons to sound so different. Again, nothing we can do to convince, or even influence them lol..
What about TLS Guy, did he believe? :D

Well as long as everyone can agree to disagree when we disagree. :D
 
P

PENG

Audioholic Slumlord
What about TLS Guy, did he believe? :D

Well as long as everyone can agree to disagree when we disagree. :D
Funny enough, on that I think he believes, at least in terms of real world use because I remember he mentioned more than once before, that while most speakers really should be rated 4 ohm nominal, he also expressed that the very few truly "difficult to drive" speakers are of poor design. On example he commented on was some of those big Polk Audio towers such as the older design, the RTI, or RTIA 9. Though he definitely never recommended using AVRs, let alone to drive 4 ohm speakers, but that's something he believes regardless, not exactly the same as dlaloun, who actually used and are using AVRs, but he simply would focus a lot of specific models that he believes are "high current" capable and that's the exact point I took issue with, that, imo, he's misguided in some ways, not understanding enough about what I cited before.

Our friend @dlaloum is very knowledgeable on this topic but for some reasons he just got so deeply fixated (no offense) on that one point about those rare below 2 ohm dips with/without aligning with nasty phase angles being a general concern to the regular forum posters..

To summarize the counter points I posted on forum before:

1) A single number rated as nominal impedance by manufacturers, 4,6 or 8 ohm is not a good indicator for people to decide on whether their AVR can handle it.
1) Many 4 ohm nominal speakers don't have dips below 2 ohms, 2.5, 3 ohms yes but below 2 ohms would be rare.
2) Most 4 ohm nominal speakers don't have nasty phase angles and low impedance in the mid bass range but in the deep bass or lower mid bass range that in most cases would be taken care of by subwoofers.
3) EPDR, (Equivalent peak dissipation resistance, EPDR | AV NIRVANA ) if often, or even mostly misunderstood, in the sense that many thought if EPDR shows a 1.5 ohm dip in the EPDR curve (vs frequency) then you need a truly "high current" amp, and therefore forget about using an AVR, except (as dlaloun alluded to) the truly flagship class ones such as the Onkyo models he cited.
4) Impedance, EPDR or not, is just one thing to consider, other important factors are of course, speaker sensitivity, and listening distance because as we know every 3 dB drop in sensitivity would mean 2X amp power for the same spl, and for distance, it is 6 dB for each doubling.

Based on just the above, it is better to consider the amp's rated voltage, and current at say below 0.1 % THD so we know it is not at clipping as such, instead of rated power. Unfortunately, amp manufacturers simply rated their amps in power output, so in order to find their equivalent rated voltage and current, one would have to resort to some calculations that not everyone knows how to do. It is, I think where our friend got into trouble with certain amps that he though based on specs should be able to drive his speaker (the one that dips to 1.6 ohm or less), while one of his beloved less "powerful" could do and thereby got misguided (my own interpretation only) by that experience.

It is easy to see the trouble of telling someone who has 4 ohm nominal, 3.2 ohm minimum speakers that has 92 dB/2.83V/m sitting 2.5 meters he/she can't use a 140 WPC Marantz SR8015, yet telling another who has 8 ohm nominal, 6.4 ohm dip speakers with 86 dB/2.83m sitting 5 meters, go do the math right!!

Based on IEC60268-3, that is similarly one of the available/applicable standard but not all manufacturers follow:
Question about Impedance | diyAudio

The trouble is, many "believers" thought they could use Ohm's law to calculate current requirements using EPDR values, whereas that would be correct. Ohm's law says current = voltage/resistance, or = voltage/|Z|, where |Z| is the magnitues, or absolute value of a complex number, you have a B.Phar so the following is mostly for non science educated readers, or those who have already forgotten what they learn in high school math classes:

vector spaces - Definition of Absolute Value of a Complex Number - Mathematics Stack Exchange

So, regardless of phase angle, if the output of an amp is 30 V, and the impedance is 3 ohm, the current would still be 30/3 = 10 A, whether the phase angle is 0 degree or 45 degrees, except that if it is 45 degrees, then the amplifier would have to dissipate a lot more heat in the output stage vs if it is at 0 degree.

It is EPDR that typically would show impedance dips to below 2 ohms, though there are some speakers, such as the one dlaloum has, that have dips below 2 ohms without using the EPDR value (a calculated value).

Below is one example, pasted from a KEF white paper, you can see how people could easily be misled, if they only have limited understanding of the theories behind:

How often do people see the actual EPDR impedance curves and understand their implications, without at the minimum read the fine prints, notes, and the full context?

1711371020468.png
 
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Eppie

Eppie

Audioholic Ninja
Thanks Eppie
Good point about the hdmi version. I read a very positive review on here (link below) that there was a hdmi upgrade available when the X8500H was first released. Will check if the unit has had the upgrade before I commit, as I will also need to factor in the cost to do the upgrade.

4K should do me tbh.
I don't think I will miss HDR10+, as I've not heard of it until now? What does not having it mean in practice?

HDR10+ is just another video standard that yields very bright high contrast images. Your source devices and TV need to support it and it must be in the source content. The trend seems to be towards DolbyVision so I wouldn't say that it's a must have. If using Netflix or other streaming services they will usually show what standards are being used in the show's description. Some gaming systems use it a well. There are others in the forum like Trebdp83 that are much more knowledgeable on this topic.
 
D

dlaloum

Full Audioholic
Funny enough, on that I think he believes, at least in terms of real world use because I remember he mentioned more than once before, that while most speakers really should be rated 4 ohm nominal, he also expressed that the very few truly "difficult to drive" speakers are of poor design. On example he commented on was some of those big Polk Audio towers such as the older design, the RTI, or RTIA 9. Though he definitely never recommended using AVRs, let alone to drive 4 ohm speakers, but that's something he believes regardless, not exactly the same as dlaloun, who actually used and are using AVRs, but he simply would focus a lot of specific models that he believes are "high current" capable and that's the exact point I took issue with, that, imo, he's misguided in some ways, not understanding enough about what I cited before.

Our friend @dlaloum is very knowledgeable on this topic but for some reasons he just got so deeply fixated (no offense) on that one point about those rare below 2 ohm dips with/without aligning with nasty phase angles being a general concern to the regular forum posters..

To summarize the counter points I posted on forum before:

1) A single number rated as nominal impedance by manufacturers, 4,6 or 8 ohm is not a good indicator for people to decide on whether their AVR can handle it.
1) Many 4 ohm nominal speakers don't have dips below 2 ohms, 2.5, 3 ohms yes but below 2 ohms would be rare.
2) Most 4 ohm nominal speakers don't have nasty phase angles and low impedance in the mid bass range but in the deep bass or lower mid bass range that in most cases would be taken care of by subwoofers.
3) EPDR, (Equivalent peak dissipation resistance, EPDR | AV NIRVANA ) if often, or even mostly misunderstood, in the sense that many thought if EPDR shows a 1.5 ohm dip in the EPDR curve (vs frequency) then you need a truly "high current" amp, and therefore forget about using an AVR, except (as dlaloun alluded to) the truly flagship class ones such as the Onkyo models he cited.
4) Impedance, EPDR or not, is just one thing to consider, other important factors are of course, speaker sensitivity, and listening distance because as we know every 3 dB drop in sensitivity would mean 2X amp power for the same spl, and for distance, it is 6 dB for each doubling.

Based on just the above, it is better to consider the amp's rated voltage, and current at say below 0.1 % THD so we know it is not at clipping as such, instead of rated power. Unfortunately, amp manufacturers simply rated their amps in power output, so in order to find their equivalent rated voltage and current, one would have to resort to some calculations that not everyone knows how to do. It is, I think where our friend got into trouble with certain amps that he though based on specs should be able to drive his speaker (the one that dips to 1.6 ohm or less), while one of his beloved less "powerful" could do and thereby got misguided (my own interpretation only) by that experience.

It is easy to see the trouble of telling someone who has 4 ohm nominal, 3.2 ohm minimum speakers that has 92 dB/2.83V/m sitting 2.5 meters he/she can't use a 140 WPC Marantz SR8015, yet telling another who has 8 ohm nominal, 6.4 ohm dip speakers with 86 dB/2.83m sitting 5 meters, go do the math right!!

Based on IEC60268-3, that is similarly one of the available/applicable standard but not all manufacturers follow:
Question about Impedance | diyAudio

The trouble is, many "believers" thought they could use Ohm's law to calculate current requirements using EPDR values, whereas that would be correct. Ohm's law says current = voltage/resistance, or = voltage/|Z|, where |Z| is the magnitues, or absolute value of a complex number, you have a B.Phar so the following is mostly for non science educated readers, or those who have already forgotten what they learn in high school math classes:

vector spaces - Definition of Absolute Value of a Complex Number - Mathematics Stack Exchange

So, regardless of phase angle, if the output of an amp is 30 V, and the impedance is 3 ohm, the current would still be 30/3 = 10 A, whether the phase angle is 0 degree or 45 degrees, except that if it is 45 degrees, then the amplifier would have to dissipate a lot more heat in the output stage vs if it is at 0 degree.

It is EPDR that typically would show impedance dips to below 2 ohms, though there are some speakers, such as the one dlaloum has, that have dips below 2 ohms without using the EPDR value (a calculated value).

Below is one example, pasted from a KEF white paper, you can see how people could easily be misled, if they only have limited understanding of the theories behind:

How often do people see the actual EPDR impedance curves and understand their implications, without at the minimum read the fine prints, notes, and the full context?

View attachment 66624
I do come from an edge case perspective, having owned electrostatic speakers for decades (which typically are easy loads in the bass, and have lower impedance - often down to 1ohm - at higher frequencies and often as reactive capacitive loads).

And when I had to retire my stats for WAF reasons, I chose another oddball design (Anthony Gallo Reference 3.2) which has a tricky very low impedance and capacitive tweeter...

This means that the speakers I have owned since the late 1980's have always been sensitive to amps...

There is an interesting discussion of amp reactivity into difficult loads here:
Audiogon Discussion Forum

In terms of power/current/impedance capabilities, the graph provided by Quad in their 606 power amp manual is interesting:

Quad 606 power chart.jpg


This is one of the most useful expressions of what an amps capabilities are that I have seen anywhere.

One can only wish that most manufacturers quoted their amp capabilities this way!

Pretty much every amp could be represented this way - and it really clearly shows what happens to your power output when the amp starts to reach the limit of its current capabilities...

At 8ohm it shows circa 135W ... which is indeed the amps basic rating
At 4 ohm 175W ... no doubling here... it seems current constrained (and the chart specifically labels these two lines as current limits... one being the transient limit and the other the continuous)
at 1 ohm we are down to a mere 40W continuous (which for the same V, would equate to around 5W!)

So here we have a high quality audiophile amplifier, officially rated to be unconditionally stable into ANY load (something almost no one else claims!) - but if you are driving a 1ohm load you will effectively be limited to the SPL's available at 5W (equivalent... for 8ohm)

Speaking pragmatically - 5W, in the higher frequency registers, is more than I am likely to need - and even with my inefficient 86db/wm speakers, provides me with circa 96db @ 1m continuous - which is well beyond the levels at which I listen (and it obviously has greater transient capabilities - as shown on the graph - about double the power, or an additional 3db of headroom)

And of course, this limitation only is applicable to the parts of the frequency range where the speaker impedance (and phase angles, EPDR) take it into difficult territory.
But as long as you are under those lines on the chart.... you won't generate additional nasty distortions.

Now with AVR's I can only guess at what their equivalent to this chart would be - most of them outright do not support 1ohm loads - they certainly aren't rated for them! - often their ratings only go to 4ohm (in some cases 6 ohm).

My Crown XLS amps, are rated down to 2ohm - with 1200W@2ohm... I can only guess what they are capable of at 1ohm - it is almost certainly substantially lower than at 2ohm, but could be 10x or more the power the Quad 606 can put into 1 ohm (1200W@2ohm is 24.5A , 49V, same current at 1ohm = 600W )

All of which is to say, if you want your audio "pristine" - you need to keep your amp envelope under the lines shown on the Quad power chart.. (or your amp/AVR's equivalent) - FOR THE ENTIRE FREQUENCY RANGE (which includes your speakers worst case EPDR) - sadly we don't have such a chart for most amps! - as soon as you push an amp above those lines, distortion of various types will start to rise exponentially... at what point will it cross the threshold of audibility? well that is a how long is a piece of string question isn't it!

I am just guessing with the particular case of my AVR - it is rated at 100W@8ohm it's close relative the RZ50/LX505 is bench tested at 144W@8ohm - and 141W@4ohm so it is heavily current limited (5.9A)
Assuming the same design for its baby brother... 95W@4ohm = 4.9A, 19.5V - and that current (4.9A) into 2ohm would be 48W & 9.8V - as you can see we are quickly coming up against some quite severe constraints.... at 1.6ohm (using my speaker as an example) that would be around 39W 8V.... and for an SPL understanding.... 8V equates to circa 8W at 8ohm....

So the best I can expect from my 100W AVR... is 8W of clean power into my personal speakers - anything more than that, and I will have to accept rising distortions of various sorts.

And yes - there are AVR's that have much higher current capabilities and will do much better with such speakers (and I have owned a couple of them over the last 20 years) - I expect the Denon A1H would be one such example.

As to what you need for a specific set of speakers - you need to have a chart of the EPDR - so you can determine what the worst case "impedance equivalent" is - and then find an AVR or amp, that can supply the power/V/current needed to achieve the SPL's you are targeting in your room ....

Backing away from all the maths.... speakers that are nominally 6ohm or higher should be fine with pretty much any AVR. Speakers that are 4ohm nominal - require some additional research...

And not wanting to panic anyone - but real life power requirements are far lower than most people think... my peak responding power level LED's have never lit up the 60W@8ohm (22V) -10db from clipping LED in actual use, regardless of how loud or dynamic the material was, the next LED down, (-20db from clip) which lights up very very rarely is at 3.4W / 5.2V - and only every lights up at the most extreme dynamic material (and I am told off by the family if it is that loud!) - In theory my baby AVR should be capable of around 8V into my speakers... - but this is based on a bunch of rough rule of thumbs estimations (as shown above) - and in order of magnitude terms, 8V is far too close to the 5.2V peak that I occasionally go over.
In subjective terms - the AVR sounded inferior to the alternate (more powerful / higher current) alternatives I compared it to.
 
T

Trebdp83

Audioholic Spartan
Yeah, if a screaming deal on the 6700 can be had, get it. If the 7.1 EXT. IN on the 1910 is being used and is still needed, get the 8500. Don’t worry about HDR10+.
 
B

beldandolgin

Audiophyte
Funny enough, on that I think he believes, at least in terms of real world use because I remember he mentioned more than once before, that while most speakers really should be rated 4 ohm nominal, he also expressed that the very few truly "difficult to drive" speakers are of poor design. On example he commented on was some of those big Polk Audio towers such as the older design, the RTI, or RTIA 9. Though he definitely never recommended using AVRs, let alone to drive 4 ohm speakers, but that's something he believes regardless, not exactly the same as dlaloun, who actually used and are using AVRs, but he simply would focus a lot of specific models that he believes are "high current" capable and that's the exact point I took issue with, that, imo, he's misguided in some ways, not understanding enough about what I cited before.

Our friend @dlaloum is very knowledgeable on this topic but for some reasons he just got so deeply fixated (no offense) on that one point about those rare below 2 ohm dips with/without aligning with nasty phase angles being a general concern to the regular forum posters..

To summarize the counter points I posted on forum before:

1) A single number rated as nominal impedance by manufacturers, 4,6 or 8 ohm is not a good indicator for people to decide on whether their AVR can handle it.
1) Many 4 ohm nominal speakers don't have dips below 2 ohms, 2.5, 3 ohms yes but below 2 ohms would be rare.
2) Most 4 ohm nominal speakers don't have nasty phase angles and low impedance in the mid bass range but in the deep bass or lower mid bass range that in most cases would be taken care of by subwoofers.
3) EPDR, (Equivalent peak dissipation resistance, EPDR | AV NIRVANA ) if often, or even mostly misunderstood, in the sense that many thought if EPDR shows a 1.5 ohm dip in the EPDR curve (vs frequency) then you need a truly "high current" amp, and therefore forget about using an AVR, except (as dlaloun alluded to) the truly flagship class ones such as the Onkyo models he cited.
4) Impedance, EPDR or not, is just one thing to consider, other important factors are of course, speaker sensitivity, and listening distance because as we know every 3 dB drop in sensitivity would mean 2X amp power for the same spl, and for distance, it is 6 dB for each doubling.

Based on just the above, it is better to consider the amp's rated voltage, and current at say below 0.1 % THD so we know it is not at clipping as such, instead of rated power. Unfortunately, amp manufacturers simply rated their amps in power output, so in order to find their equivalent rated voltage and current, one would have to resort to some calculations that not everyone knows how to do. Yes, sometimes it can be difficult to understand how science works. But read it again if you're interested. However, I had a friend in college who said that it was easier for him to go to https://edubirdie.com/science-help than to understand the intricacies of homework. Well, it’s his choice, but it was more interesting for me to get to the truth on my own. It is, I think where our friend got into trouble with certain amps that he though based on specs should be able to drive his speaker (the one that dips to 1.6 ohm or less), while one of his beloved less "powerful" could do and thereby got misguided (my own interpretation only) by that experience.

It is easy to see the trouble of telling someone who has 4 ohm nominal, 3.2 ohm minimum speakers that has 92 dB/2.83V/m sitting 2.5 meters he/she can't use a 140 WPC Marantz SR8015, yet telling another who has 8 ohm nominal, 6.4 ohm dip speakers with 86 dB/2.83m sitting 5 meters, go do the math right!!

Based on IEC60268-3, that is similarly one of the available/applicable standard but not all manufacturers follow:
Question about Impedance | diyAudio

The trouble is, many "believers" thought they could use Ohm's law to calculate current requirements using EPDR values, whereas that would be correct. Ohm's law says current = voltage/resistance, or = voltage/|Z|, where |Z| is the magnitues, or absolute value of a complex number, you have a B.Phar so the following is mostly for non science educated readers, or those who have already forgotten what they learn in high school math classes:

vector spaces - Definition of Absolute Value of a Complex Number - Mathematics Stack Exchange

So, regardless of phase angle, if the output of an amp is 30 V, and the impedance is 3 ohm, the current would still be 30/3 = 10 A, whether the phase angle is 0 degree or 45 degrees, except that if it is 45 degrees, then the amplifier would have to dissipate a lot more heat in the output stage vs if it is at 0 degree.

It is EPDR that typically would show impedance dips to below 2 ohms, though there are some speakers, such as the one dlaloum has, that have dips below 2 ohms without using the EPDR value (a calculated value).

Below is one example, pasted from a KEF white paper, you can see how people could easily be misled, if they only have limited understanding of the theories behind:

How often do people see the actual EPDR impedance curves and understand their implications, without at the minimum read the fine prints, notes, and the full context?

View attachment 66624
Thanks, that's detailed enough, although my brain is starting to boil slowly :).
So, basically, 'high current' is some kind of marketing move that isn't necessary for everyone or all the time, right?
 
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PENG

Audioholic Slumlord
Thanks, that's detailed enough, although my brain is starting to boil slowly :).
So, basically, 'high current' is some kind of marketing move that isn't necessary for everyone or all the time, right?
Basically yes, lots of marketing for sure, for example, Denon, Marantz, Onkyo and other AVR manufacturers will use the term "high-current" amplifiers to describe even their entry level AVRs. Nothing wrong technically speaking, until you want to find out how high is "high", there is no definition! Some say if it doubles down then it is high current, but that's easily debunked too if one looks into the details. People should just stop using, and/or paying attention to such terms that have no standard and adequate definition.

The important thing is to find out if the amp you have in mind could deliver the current your speakers need, for your specific application.

avr-x2800h-info-sheet-en.pdf (denon.com)

1711451635870.png
 
cpp

cpp

Audioholic Ninja
With AVRs it is the video specs you need to be concerned with as outdated specs can lead to possible issues in the future. The X8500H has the latest HDCP 2.2 spec and I would assume the latest HDMI spec as well. Will you need 8k in the future or is 4k enough? If 4k will suffice, then the unit supports DTS-X and Dolby Vision, so it just lacks HDR10+ which may not be an issue for you. If the setup microphone is included (required to use Audyssey room correction) and the price is right then it could be a good option.
? is there even any 8k content out there.
 
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