Understanding speaker power rating vs sensitivity

[highfigh]

Low impedance / high phase angles (low EPDR) speakers are the bane of receivers....

You have to go up to flagship models to have any chance of driving such speakers properly... The Onkyo RZ70 (and brethren) will probably do it, and so will the Denon A series AVR's - but the Denon X series are likely to have issues...

I have "difficult" Main speakers, and I use a pair of Crown XLS2500's to drive them.... 440W@8ohm 1200W@2ohm - however I have also used my Quad 606 power amps to drive them with 135W@8ohm, 32W@2ohm ... and there is no audible difference between the Quad and the Crown... but the AVR (Integra DRX3.4) gets midrange muddled, imaging collapses etc... use the same AVR as a prepro, with one of the two power amps I mentioned, and the sound clears up right away.

It isn't about power... the power amp has to be stable into the difficult load - many designs have rising distortion into difficult loads... they need to have both stability and high current capabilities to handle such loads. Many amps (and AVR's) simply can't do it.
Look for amps that are rated/specced at 2ohm.... (most are not!)

Or, people can make the statement that extreme impedance dips won't be tolerated, by not buying speakers with that problem and it IS a problem.

 

[PENG]

Wow. This is it!

I don’t get it quite to your level, but the dB increase quite a bit. At minus 3 it is approaching 90 which is more than enough. But then my sub amp gave up so I ordered a new resistor it seems to be a common problem.

Now, technically, what would happen if I added a third woofer to the speaker and just soldered it to the same place at the crossover (LF) as the two other woofers?

What is your listening distance? This is one of the most important thing to measure at your listening position before concluding your amp power requirements. If you sit at 1 m, you should get about 90-92 dB based on measured result of those large Klipsch speakers such as the RF-7 that the specs claim 100 dB but if you do a power search on the internet you will find that based reports by those who apparently measured it with pink noise or claimed according to Klipsch engineers (as opposed to marketing) the actual sensitivity could be between 93 to 100 dB /w/m.

On the conservative side, I would therefore consider the RF-7 can do at least 93 dB/w/m but only 90 dB/2.83V/m because they surely look more like 4 ohm nominal than 8 ohm nominal.

Now, if you calculate the "power" required, or use an online calculator you will get the following:

1) 81 dB from 13 ft, with one speaker placed near a wall

2) You mentioned C40, volume at -8 to -5, lets use -6 to make the math simpler, then if at 0, post Audyssey, you should be getting 85 dB at your MLP, so at -6 you should get about 102 dB.

3) The 102 dB I arrived at in 2) is not consistent with you posted "I took a measurement from listening position now, an SPL there is high in the 70’s as far as dB. It can do maybe 83 but this is as high as I want to push my setup. this is about minus 5dB on the amp volume, and the amp heats up. "
So I am interested to know which spl meter you used, often people used free phone apps that aren't very good for such purposes. I can see a discrepancy of a few dB, but the 102 dB (@dlaloum 's number's show even a higher number because he had an error in the distance factor), and you measure 83 dB is too much and that's what made you wonder why you would need to add that XTC amp right?

3) With the C40 volume at -6, the preamp output voltage will be slightly above 1 V, nowhere near it's clipping point of at least of around 4 V. So the C40 is not the source of your perceived distortion rising at volume -6, but at that point, it's build in power amp will be close to or exceed the clipping point.

4) It is important to understand that just because you are getting 79 dB (even if that is the right number) from your MLP at around volume -5, does not mean the preamp voltage will be just above 1 V, I would use 1.12 V for easier math, and the internal amp will be at the rated 125 W because:

a) The Marantz C40's internal amp's gain is about 29 dB, so if the preamp output is at say 1.12
V, the C40's speaker output will be at its rated 125 V, but wait, that's into 8 ohms, the RF-7 is more like a 4 ohm speaker so to the C40, it would have to deliver twice as much current, and the equivalent wattage (a wrong term to use but I have to go along with it for now) will then be 250 W.

b) More importantly, all such calculations, estimations above are based on standards that while should be applicable to bench tests and movie tracks, for music there is no such standard, we all know some CDs, stream sources such as Youtube, Qobuz, Amazon etc., do show variation in their recording level, so volume -5 may only push the C40 to output 250 W average, it could/may push it to well above that if you listening to various streaming sources and various discs such as CDs, SACDs etc.

Based on the above, if we trust science, for your seemingly very loud SPL requirements, no AVR can do it for you, not even the most powerful Denon, Yamaha, and Onkyo flagship (I mean the real flagships) from 10 plus years ago can do it for you. You did the right thing adding the XTC power amp.

Conclusion

Yes you do need an amp like the XTC, as you seems to be willing to listen to reference level or higher. I hope you don't do that for longer than a few minutes continuously at such high level.

Maths and science works, and thanks to the details you provided so far, except the distance, so I have to assume 4 meters but you can made adjustments easily as follow:

used sensitivity 90 dB/2.83V/m or 93 dB/2W/m, 2W because RF-7's nominal is likely closer to 4 ohms
Spl vs distance:

I rushed a bit, if anyone noticed errors below please alert me, thanks.

1 m.............................93 dB
1.5m...........................89.5 dB
2m..............................87 dB
2.5m...........................85 dB
3m..............................83.5
3.5m...........................82.1
4m..............................81 dB

That's for 1 W, so for 2, 4, 16, 32, 64, 128 W, double add 3, 6, 9, 12, 15, 18 dB accordingly, for example:

4m, 128 W will get you about 99 or 100.1 dB at 1 m, that would be 6 dB below reference level, so, 125 W output from the C40 will not get you reference level at 4 m, and that is with it driving just one speaker

The C40 will not be able to drive such speakers on a continuous level at reference level and it will fail if you try too often. Again you have done the right right thing adding the XTC power amp.

You would be okay without the help of the power amp, if your distance is 2 meter, or you dial your volume down to -10 or lower.

 

[PENG]

Distance from the speaker - the level halves (drops 3db) for every doubling of the distance - so if you listen at 2m (6ft) from the speakers, the level will be 3db down on base spec. (you can find calculators for distances that don't divide neatly!)

It drops 6 dB for each doubling in distance.

Increasing the level by 3db, requires doubling the power input

So here is your starting point:

1) Speaker sensitivity SPL = 90db (for 1W input @ speaker nominal impedance)
2) Stereo speakers +3db = 93db
3) Listening distance 2m = -3db = 90db

So looking at power requirements:

90db = 1W
93db = 2W
96db = 4W
99db = 8W
102db = 16W
105db = 32W
110db = 64W

As you can see, assuming a 90db SPL/wm speaker, you don't need massive power to go very very seriously loud!

A useful table but please make the necessary corrections.

 

[Petrolhead]

What is your listening distance? This is one of the most important thing to measure at your listening position before concluding your amp power requirements. If you sit at 1 m, you should get about 90-92 dB based on measured result of those large Klipsch speakers such as the RF-7 that the specs claim 100 dB but if you do a power search on the internet you will find that based reports by those who apparently measured it with pink noise or claimed according to Klipsch engineers (as opposed to marketing) the actual sensitivity could be between 93 to 100 dB /w/m.

On the conservative side, I would therefore consider the RF-7 can do at least 93 dB/w/m but only 90 dB/2.83V/m because they surely look more like 4 ohm nominal that 8 ohm nominal.

Now, if you calculate the "power" required, or use an online calculator you will get the following:

1) 81 dB from 13 ft, with one speaker placed near a wall

2) You mentioned C40, volume at -8 to -5, lets use -6 to make the math simpler, then if at 0, post Audyssey, you should be getting 85 dB at your MLP, so at -6 you should get about 102 dB.

3) The 102 dB I arrived at in 2) is not consistent with you posted "I took a measurement from listening position now, an SPL there is high in the 70’s as far as dB. It can do maybe 83 but this is as high as I want to push my setup. this is about minus 5dB on the amp volume, and the amp heats up. "
So I am interested to know which spl meter you used, often people used free phone apps that aren't very good for such purposes. I can see a discrepancy of a few dB, but the 102 dB (@dlaloum 's number's show even a higher number because he had an error in the distance factor), and you measure 83 dB is too much and that's what made you wonder why you would need to add that XTC amp right?

3) With the C40 volume at -6, the preamp output voltage will be slightly above 1 V, nowhere near it's clipping point of at least of around 4 V. So the C40 is not the source of your perceived distortion rising at volume -6, but at that point, it's build in power amp will be close to or exceed the clipping point.

4) It is important to understand that just because you are getting 79 dB (even if that is the right number) from your MLP at around volume -5, does not mean the preamp voltage will be just above 1 V, I would use 1.12 V for easier math, and the internal amp will be at the rated 125 W because:

a) The Marantz C40's internal amp's gain is about 29 dB, so if the preamp output is at say 1.12
V, the C40's speaker output will be at its rated 125 V, but wait, that's into 8 ohms, the RF-7 is more like a 4 ohm speaker so to the C40, it would have to deliver twice as much current, and the equivalent wattage (a wrong term to use but I have to go along with it for now) will then be 250 W.

b) More importantly, all such calculations, estimations above are based on standards that while should be applicable to bench tests and movie tracks, for music there is no such standard, we all know some CDs, stream sources such as Youtube, Qobuz, Amazon etc., do show variation in their recording level, so volume -5 may only push the C40 to output 250 W average, it could/may push it to well above that if you listening to various streaming sources and various discs such as CDs, SACDs etc.

Based on the above, if we trust science, for your seemingly very loud SPL requirements, no AVR can do it for you, not even the most powerful Denon, Yamaha, and Onkyo flagship (I mean the real flagships) from 10 plus years ago can do it for you. You did the right thing adding the XTC power amp.

Conclusion

Yes you do need an amp like the XTC, as you seems to be willing to listen to reference level or higher. I hope you don't do that for longer than a few minutes continuously at such high level.

Maths and science works, and thanks to the details you provided so far, except the distance, so I have to assume 4 meters but you can made adjustments easily as follow:

used sensitivity 90 dB/2.83V/m or 93 dB/2W/m, 2W because RF-7's nominal is likely closer to 4 ohms
Spl vs distance:

I rushed a bit, if anyone noticed errors below please alert me, thanks.

1 m.............................93 dB
1.5m...........................89.5 dB
2m..............................87 dB
2.5m...........................85 dB
3m..............................83.5
3.5m...........................82.1
4m..............................81 dB

That's for 1 W, so for 2, 4, 16, 32, 64, 128 W, double add 3, 6, 9, 12, 15, 18 dB accordingly, for example:

4m, 128 W will get you about 105 dB that would be reference level, so, 128 W output from the C40 will get you reference level at 4 m, but that is with it driving just one speaker

The C40 will not be able to drive such speakers on a continuous level at reference level and it will fail if you try too often. Again you have done the right right thing adding the XTC power amp.

You would be okay without the help of the power amp, if your distance is 2 meter, or you dial your volume down to -10 or lower.

What is your listening distance? This is one of the most important thing to measure at your listening position before concluding your amp power requirements. If you sit at 1 m, you should get about 90-92 dB based on measured result of those large Klipsch speakers such as the RF-7 that the specs claim 100 dB but if you do a power search on the internet you will find that based reports by those who apparently measured it with pink noise or claimed according to Klipsch engineers (as opposed to marketing) the actual sensitivity could be between 93 to 100 dB /w/m.

On the conservative side, I would therefore consider the RF-7 can do at least 93 dB/w/m but only 90 dB/2.83V/m because they surely look more like 4 ohm nominal that 8 ohm nominal.

Now, if you calculate the "power" required, or use an online calculator you will get the following:

1) 81 dB from 13 ft, with one speaker placed near a wall

2) You mentioned C40, volume at -8 to -5, lets use -6 to make the math simpler, then if at 0, post Audyssey, you should be getting 85 dB at your MLP, so at -6 you should get about 102 dB.

3) The 102 dB I arrived at in 2) is not consistent with you posted "I took a measurement from listening position now, an SPL there is high in the 70’s as far as dB. It can do maybe 83 but this is as high as I want to push my setup. this is about minus 5dB on the amp volume, and the amp heats up. "
So I am interested to know which spl meter you used, often people used free phone apps that aren't very good for such purposes. I can see a discrepancy of a few dB, but the 102 dB (@dlaloum 's number's show even a higher number because he had an error in the distance factor), and you measure 83 dB is too much and that's what made you wonder why you would need to add that XTC amp right?

3) With the C40 volume at -6, the preamp output voltage will be slightly above 1 V, nowhere near it's clipping point of at least of around 4 V. So the C40 is not the source of your perceived distortion rising at volume -6, but at that point, it's build in power amp will be close to or exceed the clipping point.

4) It is important to understand that just because you are getting 79 dB (even if that is the right number) from your MLP at around volume -5, does not mean the preamp voltage will be just above 1 V, I would use 1.12 V for easier math, and the internal amp will be at the rated 125 W because:

a) The Marantz C40's internal amp's gain is about 29 dB, so if the preamp output is at say 1.12
V, the C40's speaker output will be at its rated 125 V, but wait, that's into 8 ohms, the RF-7 is more like a 4 ohm speaker so to the C40, it would have to deliver twice as much current, and the equivalent wattage (a wrong term to use but I have to go along with it for now) will then be 250 W.

b) More importantly, all such calculations, estimations above are based on standards that while should be applicable to bench tests and movie tracks, for music there is no such standard, we all know some CDs, stream sources such as Youtube, Qobuz, Amazon etc., do show variation in their recording level, so volume -5 may only push the C40 to output 250 W average, it could/may push it to well above that if you listening to various streaming sources and various discs such as CDs, SACDs etc.

Based on the above, if we trust science, for your seemingly very loud SPL requirements, no AVR can do it for you, not even the most powerful Denon, Yamaha, and Onkyo flagship (I mean the real flagships) from 10 plus years ago can do it for you. You did the right thing adding the XTC power amp.

Conclusion

Yes you do need an amp like the XTC, as you seems to be willing to listen to reference level or higher. I hope you don't do that for longer than a few minutes continuously at such high level.

Maths and science works, and thanks to the details you provided so far, except the distance, so I have to assume 4 meters but you can made adjustments easily as follow:

used sensitivity 90 dB/2.83V/m or 93 dB/2W/m, 2W because RF-7's nominal is likely closer to 4 ohms
Spl vs distance:

I rushed a bit, if anyone noticed errors below please alert me, thanks.

1 m.............................93 dB
1.5m...........................89.5 dB
2m..............................87 dB
2.5m...........................85 dB
3m..............................83.5
3.5m...........................82.1
4m..............................81 dB

That's for 1 W, so for 2, 4, 16, 32, 64, 128 W, double add 3, 6, 9, 12, 15, 18 dB accordingly, for example:

4m, 128 W will get you about 105 dB that would be reference level, so, 128 W output from the C40 will get you reference level at 4 m, but that is with it driving just one speaker

The C40 will not be able to drive such speakers on a continuous level at reference level and it will fail if you try too often. Again you have done the right right thing adding the XTC power amp.

You would be okay without the help of the power amp, if your distance is 2 meter, or you dial your volume down to -10 or lower.

I have about 3,5 meters from the speakers. The calculations you have done are pretty much spot what I see now, and I don’t need to go past -10 to achieve what i was aiming for.

From the first measurements you are referring to, I basically have nothing left of the setup. I have remodeled the listening position 90 degrees so that the slanted roof is now towards me and not sideways. The 80W denon is gone, and replaced with the M40. The rp-280’s are replaced with a RF7’s and I also have a power amp I did not have before.

Everything has helped but the power amp had the most impact by miles for sure.

 

[PENG]

I have about 3,5 meters from the speakers. The calculations you have done are pretty much spot what I see now, and I don’t need to go past -10 to achieve what i was aiming for.

From the first measurements you are referring to, I basically have nothing left of the setup. I have remodeled the listening position 90 degrees so that the slanted roof is now towards me and not sideways. The 80W denon is gone, and replaced with the M40. The rp-280’s are replaced with a RF7’s and I also have a power amp I did not have before.

Everything has helped but the power amp had the most impact by miles for sure.

I did find at least one error in my post but fixed it. Regardless, the C40 cannot do the RF-7 justice based on your use case. Of course it can do a good job for some users but not for you. That part is obvious and I provided the underlying facts in my post. Your amp has impressive specs, congrats, and enjoy the music.

 

[dlaloum]

Or, people can make the statement that extreme impedance dips won't be tolerated, by not buying speakers with that problem and it IS a problem.

Didn't find any speakers within my budget that could get close to sounding like my previous electrostatics, while also meeting the WAF criteria....

The Gallo speakers have the goods in sound terms, they just have to match with an appropriate amp.

And that is now and has always been the key - there has never been a true speaker standard... early on 16ohm speakers were common, over time speakers moved to 8ohm and then 4ohm, but the difficulties of tuning speakers properly with passive crossovers, frequently led to "difficult" to drive speakers.

Speaker manufacturers should provide sufficient information (including a f/r / impedance / phase plot!) for a buyer to be able to choose an appropriate amp, and amp manufacturers should provide sufficient information (including ratings at 2ohm!) so that buyers can determine which amps will work with their speakers.

Neither is faulty...

There are plenty of 8ohm speakers out there, with dips in impedance dropping no lower than 5ohm - and if they suit you... then more luck to you!

My very nice 1980's vintage B&O Penta's are a benign 8ohm load, and pretty much any amp can drive them (although they do like a bit of power, as they are not super efficient).
But my Gallo mains with their CDT tweeters have the wide dispersion and the midrange clarity that I find so hard to find outside of electrostatics (or 5 to 6 figure megabuck speakers) - which relegates the otherwise excellent Penta, to surround duties.

But yes we do need to give due warning to people purchasing 4ohm nominal speakers... a 4 ohm nominal speaker, dropping down to 2ohm or below is not that huge a surprise...an 8ohm speaker dropping to 2ohm or below is unusual.... so the note to buyers is - approach 4 ohm speakers with caution. There is a good reason that the mass market was dominated for decades by easy to drive 8ohm designs.

(Of course nowadays, active speakers remove that issue, as the designer provides appropriate amplification internally, and crossovers being active, there are often no longer complex passive crossovers causing difficulties...)

 

[dlaloum]

It drops 6 dB for each doubling in distance.



A useful table but please make the necessary corrections.

Won't let me edit .... your correction will have to be it!

 

[lovinthehd]

Just thought I post how this ended if anyone reading is interested. So I upgraded the Klipsch RP 280F’s to RF-7, same problem, upgraded the 80W Denon receiver to Marantz Cinema 40 with 125Wand it was better, but still an issue with sound quality starting around -8 - -5 db deteriorating.

My understanding now is that I was not running in to clipping but my receiver really did not have proper control of the speakers.

Finally I got a XTC A2-400 power amp and then it was night and day. Clarity and quality was a massive step up, and now -10dB on the Marantz the experienced loudness is about the same as 0 was before. It just seems so effortless for this amp.

It was a long way, but super happy how it worked out. Hope somebody takes some measurements of the XTC because to me it is an impressive product for its price?

So lesson learned: Receivers and large speakers do not pair well contrary to YouTube reviews.

80W to 125W is fairly insignificant. Probably more your expectations. Takes a doubling of power to gain just a 3dB advantage in spl. Larger speakers tend to be more sensitive/efficient, not the other way around. Control is overused. Having significantly more power can be nice, tho. Don't know about the XTC amp, don't remember very good things about the brand off the top of my head. It still depends mostly on your listening levels and distance from the speakers mostly as far as power goes, you need it or you don't. While I do have some pretty powerful amps on my main system in my largest room, I rarely really need them over my avr's amp section.

 

[Kingnoob]

I have about 3,5 meters from the speakers. The calculations you have done are pretty much spot what I see now, and I don’t need to go past -10 to achieve what i was aiming for.

From the first measurements you are referring to, I basically have nothing left of the setup. I have remodeled the listening position 90 degrees so that the slanted roof is now towards me and not sideways. The 80W denon is gone, and replaced with the M40. The rp-280’s are replaced with a RF7’s and I also have a power amp I did not have before.

Everything has helped but the power amp had the most impact by miles for sure.

Wow way too big heavy and expensive for me but are they worth the 5k price compared to under 2k for your last models I assume ? 10” woofers are uncommon and very heavy it seems. How far are you sitting away ?
I wanted the 8” version of my icons but could only fit the 6.5” in my car /bedroom.

What is your listening distance? This is one of the most important thing to measure at your listening position before concluding your amp power requirements. If you sit at 1 m, you should get about 90-92 dB based on measured result of those large Klipsch speakers such as the RF-7 that the specs claim 100 dB but if you do a power search on the internet you will find that based reports by those who apparently measured it with pink noise or claimed according to Klipsch engineers (as opposed to marketing) the actual sensitivity could be between 93 to 100 dB /w/m.

On the conservative side, I would therefore consider the RF-7 can do at least 93 dB/w/m but only 90 dB/2.83V/m because they surely look more like 4 ohm nominal than 8 ohm nominal.

Now, if you calculate the "power" required, or use an online calculator you will get the following:

1) 81 dB from 13 ft, with one speaker placed near a wall

2) You mentioned C40, volume at -8 to -5, lets use -6 to make the math simpler, then if at 0, post Audyssey, you should be getting 85 dB at your MLP, so at -6 you should get about 102 dB.

3) The 102 dB I arrived at in 2) is not consistent with you posted "I took a measurement from listening position now, an SPL there is high in the 70’s as far as dB. It can do maybe 83 but this is as high as I want to push my setup. this is about minus 5dB on the amp volume, and the amp heats up. "
So I am interested to know which spl meter you used, often people used free phone apps that aren't very good for such purposes. I can see a discrepancy of a few dB, but the 102 dB (@dlaloum 's number's show even a higher number because he had an error in the distance factor), and you measure 83 dB is too much and that's what made you wonder why you would need to add that XTC amp right?

3) With the C40 volume at -6, the preamp output voltage will be slightly above 1 V, nowhere near it's clipping point of at least of around 4 V. So the C40 is not the source of your perceived distortion rising at volume -6, but at that point, it's build in power amp will be close to or exceed the clipping point.

4) It is important to understand that just because you are getting 79 dB (even if that is the right number) from your MLP at around volume -5, does not mean the preamp voltage will be just above 1 V, I would use 1.12 V for easier math, and the internal amp will be at the rated 125 W because:

a) The Marantz C40's internal amp's gain is about 29 dB, so if the preamp output is at say 1.12
V, the C40's speaker output will be at its rated 125 V, but wait, that's into 8 ohms, the RF-7 is more like a 4 ohm speaker so to the C40, it would have to deliver twice as much current, and the equivalent wattage (a wrong term to use but I have to go along with it for now) will then be 250 W.

b) More importantly, all such calculations, estimations above are based on standards that while should be applicable to bench tests and movie tracks, for music there is no such standard, we all know some CDs, stream sources such as Youtube, Qobuz, Amazon etc., do show variation in their recording level, so volume -5 may only push the C40 to output 250 W average, it could/may push it to well above that if you listening to various streaming sources and various discs such as CDs, SACDs etc.

Based on the above, if we trust science, for your seemingly very loud SPL requirements, no AVR can do it for you, not even the most powerful Denon, Yamaha, and Onkyo flagship (I mean the real flagships) from 10 plus years ago can do it for you. You did the right thing adding the XTC power amp.

Conclusion

Yes you do need an amp like the XTC, as you seems to be willing to listen to reference level or higher. I hope you don't do that for longer than a few minutes continuously at such high level.

Maths and science works, and thanks to the details you provided so far, except the distance, so I have to assume 4 meters but you can made adjustments easily as follow:

used sensitivity 90 dB/2.83V/m or 93 dB/2W/m, 2W because RF-7's nominal is likely closer to 4 ohms
Spl vs distance:

I rushed a bit, if anyone noticed errors below please alert me, thanks.

1 m.............................93 dB
1.5m...........................89.5 dB
2m..............................87 dB
2.5m...........................85 dB
3m..............................83.5
3.5m...........................82.1
4m..............................81 dB

That's for 1 W, so for 2, 4, 16, 32, 64, 128 W, double add 3, 6, 9, 12, 15, 18 dB accordingly, for example:

4m, 128 W will get you about 99 or 100.1 dB at 1 m, that would be 6 dB below reference level, so, 125 W output from the C40 will not get you reference level at 4 m, and that is with it driving just one speaker

The C40 will not be able to drive such speakers on a continuous level at reference level and it will fail if you try too often. Again you have done the right right thing adding the XTC power amp.

You would be okay without the help of the power amp, if your distance is 2 meter, or you dial your volume down to -10 or lower.

The Marantz C40 is only rated at 125 wpch and cost about 4k
Still should get the Klipsch relatively loud …

• 125 watts per channel into 8 ohms (20-20,000 Hz) at 0.05% THD, with 2 channels driven.

 

[TLS Guy]

Wow way too big heavy and expensive for me but are they worth the 5k price compared to under 2k for your last models I assume ? 10” woofers are uncommon and very heavy it seems. How far are you sitting away ?
I wanted the 8” version of my icons but could only fit the 6.5” in my car /bedroom.

The Marantz C40 is only rated at 125 wpch and cost about 4k
Still should get the Klipsch relatively loud …

• 125 watts per channel into 8 ohms (20-20,000 Hz) at 0.05% THD, with 2 channels driven.

Only if the speaker spec. is honest, which in the case of the Klipsch speaker we are talking about it was totally dishonest and misleading.

 

[Kingnoob]

Only if the speaker spec. is honest, which in the case of the Klipsch speaker we are talking about it was totally dishonest and misleading.

Probably closer to 88-90 sensitivity . And the lower levels no longer use cd drivers , not sure if LTS is one or not . and rp6000 for some reason weigh an additional 6 pounds over mine with the same woofer size. Not too appealing.
Gotta spend $5k+ for a compression driver with this brand for towers.

 

[dlaloum]

Wow way too big heavy and expensive for me but are they worth the 5k price compared to under 2k for your last models I assume ? 10” woofers are uncommon and very heavy it seems. How far are you sitting away ?
I wanted the 8” version of my icons but could only fit the 6.5” in my car /bedroom.

The Marantz C40 is only rated at 125 wpch and cost about 4k
Still should get the Klipsch relatively loud …

• 125 watts per channel into 8 ohms (20-20,000 Hz) at 0.05% THD, with 2 channels driven.

A few years back I picked up 2 used Crown XLS2500's for US$250 each...
(it was advertised on ebay in the pro / PA amp area)
440W@8ohm, 770W@4ohm, 1200W@2ohmh.... adequate power under ANY circumstances... totally over the top! - but I don't have to be concerned about amp related constraints... my actual usage runs at under 3W continuous and peaks have on occasion run as high as 16W maximum.
But it handles my difficult 1.6ohm speakers without any concern.

So yes, when moving from your standard circa 100W AVR's (whether that is 75W or 140W... there is not a heck of a lot in it) - for a substantive step up, you need to multiple by 3x or 4x

Each 3db of additional "loudness" requires a doubling of power... so if you want an additional 9db of headroom you go (3db + 3db + 3db) 2x2x2.... or 8x the power it can quickly go into the domain of completely ridiculous impracticality. (in theory I have circa 15db of headroom on top of my peak requirements.... seems pretty safe!)

 

[Kingnoob]

A few years back I picked up 2 used Crown XLS2500's for US$250 each...
(it was advertised on ebay in the pro / PA amp area)
440W@8ohm, 770W@4ohm, 1200W@2ohmh.... adequate power under ANY circumstances... totally over the top! - but I don't have to be concerned about amp related constraints... my actual usage runs at under 3W continuous and peaks have on occasion run as high as 16W maximum.
But it handles my difficult 1.6ohm speakers without any concern.

So yes, when moving from your standard circa 100W AVR's (whether that is 75W or 140W... there is not a heck of a lot in it) - for a substantive step up, you need to multiple by 3x or 4x

Each 3db of additional "loudness" requires a doubling of power... so if you want an additional 9db of headroom you go (3db + 3db + 3db) 2x2x2.... or 8x the power it can quickly go into the domain of completely ridiculous impracticality. (in theory I have circa 15db of headroom on top of my peak requirements.... seems pretty safe!)

what model ?
I don’t have low independence models looks like that model was discontinued I’ve never used a pro amplifier are they complicated???
Explains why good subs need so much wattage the drivers are low ohm. Although I’m stuck trying to get mediocre subs to sound good. Not going good so far

2 multi sub setup help?

I have one sub a jamo I just moved Infront of the room. And a klh in the back both are 10”. Using a Onkyo TX-NR818, these two are replaced my bigger sub that so far I’ve been forced to keep upstairs. I’ve gotten a xt32 trim of -15 all but my last try was -14. But I had to raise it to -9-10...

forums.audioholics.com

 

[Petrolhead]

Wow way too big heavy and expensive for me but are they worth the 5k price compared to under 2k for your last models I assume ? 10” woofers are uncommon and very heavy it seems. How far are you sitting away ?
I wanted the 8” version of my icons but could only fit the 6.5” in my car /bedroom.

The Marantz C40 is only rated at 125 wpch and cost about 4k
Still should get the Klipsch relatively loud …

• 125 watts per channel into 8 ohms (20-20,000 Hz) at 0.05% THD, with 2 channels driven.

Interesting question. Are the RF7’s wortj it? Well knowing what I know now I guess for the price I would actually be looking at other options like a used pair of the Arendal 1528 as they would not be to far off actually. (I’m in Norway and it seems a popular choice around here). I like the sound but they are not what they advertise them to be. Well let me put it this way, I wouldn’t swap back now for sure. Had I gone straight to a power amp from my old Denon I might actually still have had the rp-280s as I’m not to concerned with brand/size etc. I just want the system to be able to do what I want at a reasonable price.

I’m sitting at about 3,5-4 meters.

I underestimated the power need by a lot, and it is clear that you don’t need to go in to crazy volume before you get provlems with an AVR on the RF7.

It was a bummer really as the swap in speakers really did nothing and also the change to a bigger AVR did not do much either. I was looking at YouTube reviews as I really do not have good knowledge about this stuff and many run the speakers on lots of AVR’s and give them a thumbs up. Either it is for clicks or many simply don’t know or understand. Even though you are not running in to clipping you can really tell the AVR and speakers are not having a good time. If I knew the impedance of these speakers was this far of the spec, I would definitely have gone about this another way.

The plus side about this ordeal is that I learned some new things so it was not for nothing.