That's a false debate.
In absolute terms, an audio system is a tool made to reproduce sounds. An audiocopier.
There is no reason, whatsoever, why and absolute audiocopier wouldn't be able to reproduce every sound there is. Both in frequency and amplitude.
As humans, as audiophiles, as DIYers, we choose to make compromises. That's it. End of story. But in fact an absolute audiocopier would be able to make 180db @ 1hz or 100,000hz. Oh darn, that will hurt cats!
In absolute terms, an audio system is a tool made to reproduce sounds. An audiocopier.
There is no reason, whatsoever, why and absolute audiocopier wouldn't be able to reproduce every sound there is. Both in frequency and amplitude.
As humans, as audiophiles, as DIYers, we choose to make compromises. That's it. End of story. But in fact an absolute audiocopier would be able to make 180db @ 1hz or 100,000hz. Oh darn, that will hurt cats!
You have apparently seized on a statement to invalidate other valid statements made...which is otherwise called accident, or even Secundum quid. The subject at hand is "recordings show no real information below 40 Hz". This isn't true, and even the OP here has taken exception to your argument. It's a sweeping generalization that can only apply if you put on blinders and then say that the discussion is "now out of bounds".
Where would be acceptable on diyAudio, Pano? I have data--lots of it.
Chris
Last edited:
Put in over in my thread on musical spectrum. It's a better place to discuss it.
Spectrum of Musical Genres
Spectrum of Musical Genres
Jon, talking about F3 is meaningless, Toole has clearly shown that the ear/brain does not perceive this, it is only an artifact from filter theory. Much better to talk about F6 or F10.
dave
As well, if you are talking anechoic sim to -3 dB at 25 Hz, once you have it in room you will have a big bump. Anechoic -10 dB at 25 Hz is more likely give a typical (hard word to use since there is no typical room) flat to 25 Hz in room.
dave
I can see the point your are trying to make but even though something is not anywhere near what can be achieved doesn't mean it still is not enough to do the job it is intended for. There is compromise in everything. To achieve 300KPH top speed the car needs to be incredibly light, stiff and powerful. The car now costs a fortune does not fit your shopping bags, your kids, your dogs, your PA system etc.
It's a great supercar but hopeless as a daily driver.
There is nothing wrong with wanting something to be as good as it can be, the part that doesn't make sense to me is having something that is capable of so much more in one area but it never gets used because there is nowhere to use it and by having that maximum top speed you lose something else that could have been used. That was why I chose to buy a Superbike, faster 0-60 and a lot more fun! Still no room for the shopping but it was a lot cheaper 🙂
I would agree entirely with that statement. That is why I quoted Hoffman's Iron law to you before. It's easy to get loud, low or small but one 'has' to be traded for the other overall relatively speaking.
By setting the Frequency and SPL that you are aiming for will set the allowable footprint. For increased SPL at low frequency more air volume needs to be displaced. That means more Cone area or more x-max or both.
I don't think we should sacrificing FR for SPL.
FR comes first, then SPL.
Better have a full 10 octaves @ 75db than a 8 octaves @ 90db.
FR comes first, then SPL.
Better have a full 10 octaves @ 75db than a 8 octaves @ 90db.
But i still doubt 24, 50 or 200 mini drivers will equal less but bigger drivers.
I don't think Vds are created equal, so to speak. When you enter the purely pistonic world (1st octave) there is few more thing to consider than just Vd.
No, i never talk anechoic-room results as i couldnt care less about it. Always in-room real-life measurements.
Flat to 25hz in-room doesnt happen very often... I'll give you 5,000$ budget to go in any HiFi boutique to bring something that will be FLAT 25hz-20khz uncorrected, +/- 2db in-room, and i'll be very impressed if you succeed...
Actually that could be a very interesting experiment: bringing KEFs, B&W, Focal and whatnot and then measure them in the same room/position with the same equipment.
Educated-guess here: That'd be a mess. Boomy bass @ 50-70hz, no 1st octave to speak of, roll-off in highs and dips/peaks anywhere in-between.
I did that few years ago with some very expensive Sonus Faber and i was laughing.
Educated-guess here: That'd be a mess. Boomy bass @ 50-70hz, no 1st octave to speak of, roll-off in highs and dips/peaks anywhere in-between.
I did that few years ago with some very expensive Sonus Faber and i was laughing.
I would agree which is why I am so confused by your statements.
It does take the right drivers with the right specifications to be useful. There are a growing number of people who have heard or built similar arrays, they all agree that the concept works. It is a lot of effort to build a good one and it's not easy to reuse 50 of the same drivers in other projects if it fails so it takes some commitment to try.
An array is not the equal of a well built purpose designed sub driver whose only job is to produce the lowest frequencies. But as RA7 suggested the concept has more to offer than the ability to go low in a small footprint. Even room response, particularly with height, vertical directivity that reduces floor and ceiling reflections to be impossible to pick in measurements etc.
What are these few other things to consider? As far as I know volume displacement is the best way to determine the output potential of any driver. Vd is the ragged edge, the absolute maximum. In that sense it is equal. If you want that level to be free of distortion then you would aim to have more Vd so the driver is not at it's limits providing it.
Very few hifi speakers are that well controlled anechoically in the first place. Without an extremely well behaved and treated room an almost impossible challenge.
That is the beauty of DIY speakers they can be built and designed to work in the room that you have and with even directivity and the right measurements can be equalized to your preferred target in room.
This is an in room average measurement after processing. The Green line is my target response. 10 to 50Hz no smoothing applied.
Attachments
I understand a corner line array reduces reflections to a minimum, is this your primary reason for using one? The convenience of putting them in a corner and the small footprint is appealing. I mean, if you could have any speaker type is this set up what you'd choose?
It is RA7's that are in a corner, mine are free standing. For my usage case these are about as good as I could have hoped for as far as compromises go I can live with the ones these have 🙂
Corner placement has advantages but the interface between the baffle and the wall can be tricky. The room that any speaker will be used in is a big factor in which type is preferred. I don't think that there is a "best" as not everybody wants the same thing.
If money was no object and I had a room built from the ground up as a listening room then no I would choose something else.
Corner placement has advantages but the interface between the baffle and the wall can be tricky. The room that any speaker will be used in is a big factor in which type is preferred. I don't think that there is a "best" as not everybody wants the same thing.
If money was no object and I had a room built from the ground up as a listening room then no I would choose something else.
Ah, yes, sorry, thanks for your answer, I imagine your set up is very similar.
I would like to ask RA7 the same question
Below 100Hz they are quite different, above I imagine they are more similar than different.
RA7's has a small volume corner mounted cabinet as he crosses to subs to avoid having to EQ the line.
Mine are currently 1.3m from the side walls and 0.5m from the front wall and have a decent amount of EQ to get the graph shown above.
I'm sure RA7 will be along to tell you what he thinks of his setup.
RA7's has a small volume corner mounted cabinet as he crosses to subs to avoid having to EQ the line.
Mine are currently 1.3m from the side walls and 0.5m from the front wall and have a decent amount of EQ to get the graph shown above.
I'm sure RA7 will be along to tell you what he thinks of his setup.
how much processing is used?
my current speaker footprint is 0,75m2 per speaker. bass is dipole and between 385cm walls it goes straight to 40hz, goes down like cows tail after that but 30hz is still quite useful.
really refreshing to listen dipole after pressurising sealed bass
The primary benefit of line arrays in my mind is the avoidance of floor and ceiling reflections. Putting them in the corner was just the icing on the cake. I could get reflections of the far side wall, but not from the near side wall. In terms of creating/controlling spaciousness, this is ideal. The horizontal directivity is also constant throughout the range, right up to around 6 kHz or so, when the driver starts beaming.
Couple of things I would do differently:
1. Design a better baffle/wall interface. I didn't realize that walls could be less than perfectly flat.
2. Find a smaller driver that is just as good as the Vifa TC9 in other aspects. This will help push beaming up in the range. It does just fine as it is, I have no complaints, but a smaller driver would be better.
If you want to find out more:
Corner Floor-to-Ceiling Line Array Using Vifa TC9
First problem: manufacturer's specs are proven unreliable. Some are, some are not, which make comparisons (and planifications) difficult.
Second problem: mechanical noises. As pistonic movement kicks in, the whole structure and design of the transducer is stressed to the max. I'm not even talking voice coil heating or xmax/xmech, only the air trying to flow out of the basket and cone/surround/spider trying to stay in shape while shoving large volume of air in huge, very slow, vibrating movements...
You can hear most of the drivers struggling, even at low volume, well below Xmax and max power handling with a 20-30hz pure tone. They're not ''tone-pure''. In an OB that is sure not good, and even in a BR or sealed you can hear it through the port and/or cone.
That becomes less and less of a problem starting around 35hz, where you're more in ''real sound'' territory.
- Status
- Not open for further replies.