Welcome to ASR! Sorry, I will try to explain what he said. And congrats on your retirement and all the fun projects you have planned BTW. Exciting times ahead!
Firstly, this place is different to other audio forums. This is Audio Science Review. Other forums believe in "synergy", that cables sound different, and all sorts of tweaks to improve the sound. The focus here is on evaluating equipment and claims objectively and getting the most for your money. Expensive products do not necessarily perform better or sound better, in fact many of these "high end" products have misguided notions about design that objectively worsens performance. So a lot of advice given here will conflict with what you will hear in other forums and conventional hi-fi wisdom, which is why many people are antagonistic towards ASR. I hope we can demonstrate that we are a friendly bunch and our mission is to educate.
"High SPL ability" means the ability for your system to go loud, and do it cleanly (SPL = Sound Pressure Level). This means selecting speakers which are appropriately sized for your room, and providing enough amplification to hit those SPL's without clipping. I agree that this is a good goal.
"In room linearity" means that the frequency response of your loudspeaker in your room is as even as possible. The two most important factors for good sound are (1) room and (2) speakers. The moment you place speakers in any room, the room will have a major influence on the behaviour of the speaker. There are various strategies to deal with this, which we can discuss, but the first principle is select the correct and appropriate speaker, and spend a lot of thought in placing it properly in your room.
"Controlled low end" refers to the bass. The room has a major effect on bass performance, and WILL produce huge peaks and dips. My sound system is no exception, and this is a before and after measurement of my sound system:
View attachment 335823
Red = before. You can see that the curve is all over the place. Green = after room correction (I use DSP - Digital Signal Processing). The red curve is the typical performance of any speaker in any room.
A "controlled directivity" speaker is a bit more difficult to explain. You can have a stab at reading
this article by Geddes or
this article by Linkwitz. Basically, when your speaker is facing you directly, the entire audio spectrum is at its loudest (not strictly true, but I am ignoring all the other variables for the sake of simplicity). As you move off to the side, it will get softer, and parts of the audio band will drop off faster than others. Usually, higher frequencies are more "directional" (more like a flashlight that directs light into a beam), and lower frequencies are more "omnidirectional" (more like a lamp that throws light everywhere). You want the entire audio band to IDEALLY drop off at the same rate and do it smoothly, because the reflections from the side walls will reflect any unevenness back to you and colour the sound. There are various strategies to deal with this, and this has resulted in many different speaker designs.
The B&O Beosound 90 you mentioned is an omnidirectional speaker. If you remove the cover, you will see that there are speaker drivers pointing in every direction. By manipulating the output of the speakers using DSP, the
Welcome to ASR! Sorry, I will try to explain what he said. And congrats on your retirement and all the fun projects you have planned BTW. Exciting times ahead!
Firstly, this place is different to other audio forums. This is Audio Science Review. Other forums believe in "synergy", that cables sound different, and all sorts of tweaks to improve the sound. The focus here is on evaluating equipment and claims objectively and getting the most for your money. Expensive products do not necessarily perform better or sound better, in fact many of these "high end" products have misguided notions about design that objectively worsens performance. So a lot of advice given here will conflict with what you will hear in other forums and conventional hi-fi wisdom, which is why many people are antagonistic towards ASR. I hope we can demonstrate that we are a friendly bunch and our mission is to educate.
"High SPL ability" means the ability for your system to go loud, and do it cleanly (SPL = Sound Pressure Level). This means selecting speakers which are appropriately sized for your room, and providing enough amplification to hit those SPL's without clipping. I agree that this is a good goal.
"In room linearity" means that the frequency response of your loudspeaker in your room is as even as possible. The two most important factors for good sound are (1) room and (2) speakers. The moment you place speakers in any room, the room will have a major influence on the behaviour of the speaker. There are various strategies to deal with this, which we can discuss, but the first principle is select the correct and appropriate speaker, and spend a lot of thought in placing it properly in your room.
"Controlled low end" refers to the bass. The room has a major effect on bass performance, and WILL produce huge peaks and dips. My sound system is no exception, and this is a before and after measurement of my sound system:
View attachment 335823
Red = before. You can see that the curve is all over the place. Green = after room correction (I use DSP - Digital Signal Processing). The red curve is the typical performance of any speaker in any room.
A "controlled directivity" speaker is a bit more difficult to explain. You can have a stab at reading
this article by Geddes or
this article by Linkwitz. Basically, when your speaker is facing you directly, the entire audio spectrum is at its loudest (not strictly true, but I am ignoring all the other variables for the sake of simplicity). As you move off to the side, it will get softer, and parts of the audio band will drop off faster than others. Usually, higher frequencies are more "directional" (more like a flashlight that directs light into a beam), and lower frequencies are more "omnidirectional" (more like a lamp that throws light everywhere). You want the entire audio band to IDEALLY drop off at the same rate and do it smoothly, because the reflections from the side walls will reflect any unevenness back to you and colour the sound. There are various strategies to deal with this, and this has resulted in many different speaker designs.
The B&O Beosound 90 you mentioned is an omnidirectional speaker. If you remove the cover, you will see that there are speaker drivers pointing in every direction. By manipulating the output of the speakers using DSP, the Beosound 90 is able to change its radiation pattern to something more suitable for your room and listening preferences. Other speakers, like the Dutch & Dutch 8C that was mentioned, are not omnidirectional but "controlled directivity". It uses clever design of the shape of the speaker to create a close to ideal radiation pattern.
I realize that there is a lot to digest, and all I am doing is explaining his post. Thoughts of my own:
- DON'T get those McIntosh amps because they don't perform very well objectively. Of course, getting them for their aesthetics, build quality, sexy glowing tubes, and pride of ownership is a valid reason to get them, but most people on ASR are dispassionate about things like looks and only focus on performance. You can get better performance by spending less, for example getting an amp like the Benchmark AHB2.
- DON'T get a PS1250 power supply. It will not do anything to improve the sound, and it is astoundingly expensive.
- DON'T buy expensive audiophile cable. It does not perform any better than cheap cable.
- Class A amps sounding "musical" is a myth. Amplifiers can be evaluated objectively.
And lastly, speaker choice is very personal. We can suggest speakers that are known for good performance, but ultimately, nobody here can tell you which speaker to get. We can only tell you which speakers not to get, i.e. those with misguided designs, are overpriced, etc. Only you know your preferences, your room, your personal situation, whether your speaker has to fit in with your decor or not, and so on. Sometimes speaker choice is limited by what the wife will allow! All these are valid considerations above and beyond the actual performance of the speaker.
is able to change its radiation pattern to something more suitable for your room and listening preferences. Other speakers, like the Dutch & Dutch 8C that was mentioned, are not omnidirectional but "controlled directivity". It uses clever design of the shape of the speaker to create a close to ideal radiation pattern.
I realize that there is a lot to digest, and all I am doing is explaining his post. Thoughts of my own:
- DON'T get those McIntosh amps because they don't perform very well objectively. Of course, getting them for their aesthetics, build quality, sexy glowing tubes, and pride of ownership is a valid reason to get them, but most people on ASR are dispassionate about things like looks and only focus on performance. You can get better performance by spending less, for example getting an amp like the Benchmark AHB2.
- DON'T get a PS1250 power supply. It will not do anything to improve the sound, and it is astoundingly expensive.
- DON'T buy expensive audiophile cable. It does not perform any better than cheap cable.
- Class A amps sounding "musical" is a myth. Amplifiers can be evaluated objectively.
And lastly, speaker choice is very personal. We can suggest speakers that are known for good performance, but ultimately, nobody here can tell you which speaker to get. We can only tell you which speakers not to get, i.e. those with misguided designs, are overpriced, etc. Only you know your preferences, your room, your personal situation, whether your speaker has to fit in with your decor or not, and so on. Sometimes speaker choice is limited by what the wife will allow! All these are valid considerations above and beyond the actual performance of the speaker.