I have the Purifi reference as mentioned. Besides that, I have the Mark Levinson No 532 and dual No 53 monoblocks.Can i ask what amps do you have Ammir?
I have the Purifi reference as mentioned. Besides that, I have the Mark Levinson No 532 and dual No 53 monoblocks.Can i ask what amps do you have Ammir?
Am I misunderstanding... I thought room correction software drops the relative output to ensure that any corrective peaks don't clip. I would've thought that before you got clipping, you'd have a complaint about not getting loud enough...
Hi
Would a contributing factor also be the thickness of the speaker wire? To thin and it would not pass sufficient power not sure if to thick would be a problem, except what would to thick look like? Not sure about the thickness of the cables internal to the amp as they are generally very short in comparison.
Just my thoughts
Regards
William
nice, i didnt even knew that brand. is it better than benchmark?I have the Purifi reference as mentioned. Besides that, I have the Mark Levinson No 532 and dual No 53 monoblocks.
I doubt it.nice, i didnt even knew that brand. is it better than benchmark?
Gotta get your hands on the insanely expensive amps to see how good they are. Stereophile measured some $100,000 Boulder amps and I recall them measuring pretty well.I doubt it.
yeah rightGotta get your hands on the insanely expensive amps to see how good they are. Stereophile measured some $100,000 Boulder amps and I recall them measuring pretty well.
Filling in dips is a foolish journey to nowhere IMHO if the dips are due to nodes in a resonance, which they are quite likely to be.Indeed. Dirac aggressively attempts to fill in the dips and causes the amp to run out of juice.
The recording is the driver of power levels, look to the waveform for the initial clues.
The waveform represents the request for voltage from the amplifier by the recording to be applied to the speaker terminals.
As for "bass transients", uh, there aren't any. Bass is slow slow slow.
In the organ piece above, here is the highest voltage request. Ooh... looks like an abrupt change, and hard to reproduce... The clip is about 2 milliseconds in length.
View attachment 126309
Let's call that peak 50V. Loud. 625Watts into 4 ohms load loud.
Now zoom in on that "transient". The dots are sample values, and are 0.000023 seconds apart - 23 microseconds.
View attachment 126310
The slew rate - rate at which an amplifier can change voltage - "Most well designed amplifiers are flat out to 100kHz so in that case you would need a minimum slew rate of about 32V/usec in order to achieve such a wide bandwidth". - https://www.audioholics.com/audio-amplifier/amplifier-slew-rate
So, for this example, assuming 50V peak of the music waveform, might need to move 2 or 3 volts in 23 uS, well below its capability.
There are faster transients, none should really tax a decent amplifier's ability to follow the waveform, if the amplifier's bandwidth exceeds the bandwidth of the musical signal, and it can flow current as demanded by the load at the requested voltage.
As you found out, there is a reason why most amplifiers in receivers and other equipment is around 75 to 100 watts per channel. That amount of power easily allows for 90% or more of peoples volume level. In special cases where someone actually needs extra power, they can buy more but mostly 100 watts will do the trick. But since it is a hobby, people need to find (which means making up a reason) to buy a more expensive more powerful amp. So there is need and want. Most of the stuff any hobbyist is looking at is pure want and then silly reasons to justify the want. Most all of it is non-essential to very good sound reproduction with todays products. Excluding all snake oil products of course......I finally decided to make the effort to see how speaker voltage input relates to listening levels at the listening position.
Speakers are Duntech Black Knights (PCL400) - these are a five driver, three-way design from 1990 and come in at 154 pounds each, 90 dB @ 2.83V sensitivity, nominally 4 Ohms (minimum 2.8 Ohms.), over six feet in height, representing an earlier John Dunlavy design while he was in Australia.
Amps are from 1999 - Musical Fidelity X-A200 monoblocs - 200W/ch into 8 ohms, 400W/ch into 4 Ohms.
Room, about 45 square meters (484 sq ft), listening position about 3.5 meters from speakers.
Now, I've always suspected that the amplifier power was overkill, but I didn't know that in 1999, so I dragged out my DSO (digital storage oscilloscope) and actually measured the output of one of my amps at the speaker terminals for a variety of music and levels.
I was looking for voltages at musical peaks.
For ordinary music listening (e.g. Jazz) at comfortable levels, maybe half to one watt (average) was more than enough, with peaks of a few watts.
When choosing music with a significant bass component and turning up the volume to the limits of what I could stand for short periods, the music was peaking infrequently at 20V (~100W). This corresponds to approximately 104 dB at the listening position.
The above is roughly in line with the sorts of measurements that @RichB was getting if one adjusts for the differences in the speaker sensitivities.
For me, that leaves quite a bit of superfluous amp headroom, meaning that I could have survived quite well with an amp rated at just 100W @4 ohms, all other things being equal. However, it's good to know that amp power will never likely be the limitation of the system .
Perhaps an AHB2 would be a good option then should my MFs eventually die .
Indeed. In the distant past I have lived with my speakers being run with amps as low as 70W (4 Ohms). I do wonder however whether my existing amps have lasted so long - at least, in part - because most of the time they're not being stressed and therefore never become overly warm.As you found out, there is a reason why most amplifiers in receivers and other equipment is around 75 to 100 watts per channel. That amount of power easily allows for 90% or more of peoples volume level. In special cases where someone actually needs extra power, they can buy more but mostly 100 watts will do the trick. But since it is a hobby, people need to find (which means making up a reason) to buy a more expensive more powerful amp. So there is need and want. Most of the stuff any hobbyist is looking at is pure want and then silly reasons to justify the want. Most all of it is non-essential to very good sound reproduction with todays products. Excluding all snake oil products of course......
Nice video!During my chat with the The Daily HiFi guys this past Monday, the topic of higher sensitivity speakers having more dynamic range came up. I gave my condensed spiel about why I think it isn't the speakers but rather the system as a whole that when integrating higher sensitivity speakers that provide more dynamics.
In this video I address that a little bit more but with a focus on how to obtain a realistic number for how much amplifier power you need using three factors:
1) Speaker sensitivity
2) Distance from MLP to speaker
3) Dynamic range of the content you listen to
The third is key but never discussed when the topic of "how much power do I need" comes up on the forums. So, I spend some time on that aspect. If you're wanting to kill about 20 minutes listening to audio chat, I have provided the link below.
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To address a comment I already had from @MZKM:
* doubling of speakers = +3dB
* doubling of power = +3dB
* net gain of adding a speaker & its own amp channel = +6dB (theoretical)
* speaker in a room vs anechoic = +3-6dB (+3dB is the norm above the transition frequency)
I tested the +6dB doubling of speakers/power by simply using a single powered speaker and measured the FR via RTA. Then I connected the other powered speaker and measured the response. I got about +5dB from about 300Hz+. In the HF+ I noticed less overall gain, which I believe aligns with what Toole discusses in his book regarding the point where a speaker becomes more directional. In the LF the gain was anywhere from +3 to +6dB.
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I created a poll on AVSforum a year or two ago asking what the listening distance is for people from the MLP to the speakers. The poll showed 3-4m average listening distance.
I created a poll on my YT channel and my FB group asking who pays attention to the mfg spec for "recommended power". Over 80% said they pay it no mind.
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Links used:
https://dr.loudness-war.info/
https://www.crownaudio.com/how-much-amplifier-power
https://www.crownaudio.com/en-US/tools/calculators#amp_power_required