For $2000 for a floor standing speaker, I would consider the Revel F206 or the KEF R5 Meta. Neither is as impressively big and loud as the RF-7. I haven't seen any measurements of the RF-7 but I expect that the Revel and KEF both offer much better sound quality.Hi my sofa is 6.2m from where the speakers would stand.
Open to suggestions from those more versed than myself for sure!
Thank you for the concise reply.
The reason i was aiming towards class A is that i have read a lot of information about them being the 'purest sounding' amps that tend not to colour the source with any magic. This would be the easy starting point as i want the amp to sound as natural to the recording as possible. I mean, that's the goal right?
So are we saying that the difference between classes in inaudible?
The reason for the 300 watts, is to drive some RF-7 floor standers I have my eye on.
So if the power requirements of the speaker exceed the capabilities of the budget or the power, or the seaker class vs heat production. Then i need to look at something else in terms of amp class to better suit my budget/speaker requirements.
Thanks again!
Except Klipsch is widely optimistic in their sensitivity ratings. They have overstated them for decades. At best these are 92 db/w, so would require about 6 times your estimate. Even then 150w/ch would hit 105 db reference levels comfortably (which for those who don’t know, is extremely loud).OK ... the Klipsch RF-7 have a sensitivity of 100db @ 2.83V / 1m - nominal impedance is 8ohm....( we can talk about real impedance later)
If you are listening to them in a large room (requiring more power) - you could be listening to them at say 4m
The base spec, tells you that for an input of 1W (2.83V into 8 ohm) you will get Sound Pressure Level of circa 100db at 1m from the speaker (in free air, away from walls)
Distance will affect this, as the SPL will drop by 6db for each doubling of distance
So at 4m your output at 1W will be 100db - 2x6db = 88db
Assuming you are running a stereo pair, having two speakers running will double the output taking it to 88db + 3db = 91db
Now to work out what your power requirements are (roughly)...
Reference level in homes (as opposed to theatres) for continuous output at the listening position is 75db, with a 20db peaking allowance (so max of 95db) - Pro/Theatre levels are normally set as 85db continuous and +20db / 105db peak
Your power output SPL table looks like this (@8ohm)
1W 91db
2W 94db
4W 97db
8W 100db
16W 103db
32W 106db
64W 109db
128W 112db
256W 115db
So with those speakers, in a relatively large room, listening to the speakers at a 4m distance, you need a total of 4W to achieve the peak reference "home" levels of loudness... and 32W will be ample if you aim for the theatrical reference of 85db/105db (continuous/peak)
Given the above, it is highly likely that you could get by more than adequately with a 35W amp. (!!!)
A 35W class A amp could be viable within your budget, although you might have to go used...
There are a couple of complexities to take into account - although "nominally" 8ohm, a number of measurments/tests have shown that the RF7's drop down to around 4ohm... to provide the same output at 4ohm as at 8ohm requires twice the current / twice the power...
So if you need a 35W amp rated at 8ohm, you need a 64W amp rated at 4ohm... - the two are almost the same, but the 4ohm rated amp would have a larger power supply, and larger heatsinks, and possibly more transistors etc... - even though when driving an 8ohm speaker it would sound no different to an amp rated only at 8ohm. (so worthwhile checking the 4 ohm rating for the amp, given the RF7's do drop down to that level at crossover point)
P.S. for a 6m distance, you would take the power requirements up one notch on the table, as you will lose around 3 to 4db of loudness... so you will need to double the power.... from 32W to 64W @ 8ohm (assuming a pro/theatre target) or 8W for the standard "home" target
160wpc into 8 ohms is "robust"?
The point is - in reality a heck of a lot less power is needed.Except Klipsch is widely optimistic in their sensitivity ratings. They have overstated them for decades. At best these are 92 db/w, so would require about 6 times your estimate. Even then 150w/ch would hit 105 db reference levels comfortably (which for those who don’t know, is extremely loud).
Agree, except he doesn’t need a Class A amp. He needs a methodical approach, not being distracted by false distractions like Class A will transform your life.The point is - in reality a heck of a lot less power is needed.
I use 86db/w speakers and listen at a distance of circa 3m - I almost never use more than 5W - I estimate that the loudest peak my system has ever experienced would have been just under 16W.
To take it to 6m.... would require multiplying my own power requirements by 4... so rather than 16W max peaks, around 64W max peaks...
With my inefficient and difficult to drive (1.6ohm impedance) speakers.... 64W would be ample in the OP's situation
The Klipsches run a lot louder than my Gallo's - so there is every likelihood that in his setup, he would never need more than 32W.
We all like to have more "margin" / " Headroom" - just to be sure!
But a high bias Class A / AB amp, which runs in Class A up to around 30W, then switches to Class AB, would probably be the perfect alternative for the preferences discussed...
Such an amp would almost always be running in class A... avoiding crossover distortion - and it would have substantial peak capabilities beyond that "just in case".
Forget about what you have read on class A and crossover distortion on A/BThank you for the concise reply.
The reason i was aiming towards class A is that i have read a lot of information about them being the 'purest sounding' amps that tend not to colour the source with any magic. This would be the easy starting point as i want the amp to sound as natural to the recording as possible. I mean, that's the goal right?
So are we saying that the difference between classes in inaudible?
The reason for the 300 watts, is to drive some RF-7 floor standers I have my eye on.
So if the power requirements of the speaker exceed the capabilities of the budget or the power, or the seaker class vs heat production. Then i need to look at something else in terms of amp class to better suit my budget/speaker requirements.
Thanks again!
you are married good, not at all or it's a picture from a shed in the garden.What is it you are looking for?
The audiotorium is a mess, as usual...
View attachment 274094
TV: someone getting into big trouble flying into cloud near a mountain ridge without proper instruments in New Zealand.
No.The point is - in reality a heck of a lot less power is needed.
I use 86db/w speakers and listen at a distance of circa 3m - I almost never use more than 5W - I estimate that the loudest peak my system has ever experienced would have been just under 16W.
To take it to 6m.... would require multiplying my own power requirements by 4... so rather than 16W max peaks, around 64W max peaks...
With my inefficient and difficult to drive (1.6ohm impedance) speakers.... 64W would be ample in the OP's situation
The Klipsches run a lot louder than my Gallo's - so there is every likelihood that in his setup, he would never need more than 32W.
We all like to have more "margin" / " Headroom" - just to be sure!
But a high bias Class A / AB amp, which runs in Class A up to around 30W, then switches to Class AB, would probably be the perfect alternative for the preferences discussed...
Such an amp would almost always be running in class A... avoiding crossover distortion - and it would have substantial peak capabilities beyond that "just in case".
Hi
Never posted before. But I am in the search for a set of pure class a Monoblocks with a wattage output of 300w into 8ohms…..
These are not the conditions in the OPs room. In domestic rooms SPL drops much less with distance, AFAIK rather around 3 dB per doubling.OK ... the Klipsch RF-7 have a sensitivity of 100db @ 2.83V / 1m - nominal impedance is 8ohm....( we can talk about real impedance later)
If you are listening to them in a large room (requiring more power) - you could be listening to them at say 4m
The base spec, tells you that for an input of 1W (2.83V into 8 ohm) you will get Sound Pressure Level of circa 100db at 1m from the speaker (in free air, away from walls)
Distance will affect this, as the SPL will drop by 6db for each doubling of distance
I agree - the inverse square law 6db per doubling distance is for free space, not a reverberant field like an living room.These are not the conditions in the OPs room. In domestic rooms SPL drops much less with distance, AFAIK rather around 3 dB per doubling.
Some reading which may or may not be interesting to you-->As an aside, this thread has commenters claiming an audible advantage of Class AB over Class D, and others claiming audible transparency for well implemented amps of all classes.
The published double blind ABX testing of amps I've seen pre-date Class D. Are there any recent properly conducted ABX listening trials for Class AB vs D?
Which for most speakers are not that relevant. If you run electrostatics, then perhaps worry.Some reading which may or may not be interesting to you-->
NC252MP (class D) vs. A250W4R (classAB) burst measurements into 4ohm//2.2uF load
NC252MP (class D) vs. A250W4R (classAB) burst measurements into 4ohm//2.2uF load As I have been doing, quite intensively, wide range of power amplifier measurements, I have decided to compare 2 different power amplifier design philosophies, class AB and class D. The amplifiers chosen have equal...www.audiosciencereview.com
Interesting but I agree with tonycollinet - not relevent to most users. The NC252MP doesn't like a low-ESR 2.2uF cap on its output. Not something that most speakers would have. Although there isn't anything in the NC 252MP datasheet forbidding it.Some reading which may or may not be interesting to you-->
NC252MP (class D) vs. A250W4R (classAB) burst measurements into 4ohm//2.2uF load
NC252MP (class D) vs. A250W4R (classAB) burst measurements into 4ohm//2.2uF load As I have been doing, quite intensively, wide range of power amplifier measurements, I have decided to compare 2 different power amplifier design philosophies, class AB and class D. The amplifiers chosen have equal...www.audiosciencereview.com
These are not the conditions in the OPs room. In domestic rooms SPL drops much less with distance, AFAIK rather around 3 dB per doubling.
Way less actually: 6 dB which is a quarter.Which would indicate my estimates are more conservative than necessary (ie: less power is needed)
If you measure it you can find the critical distance which is where reflected sound energy equals direct sound. You'd find the first doubling from close is a 5-6 db drop. Cricitical distance is where a doubling causes a 3 db drop. Eventually the drop with doubling pretty much dissappears as you are in a reverberate field. I've found in most rooms people end up sitting about at the critical distance. In most rooms it is 3-5 meters from the speakers.These are not the conditions in the OPs room. In domestic rooms SPL drops much less with distance, AFAIK rather around 3 dB per doubling.