Burhoe Inspired Room Flooder

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Cressy Snr
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#31 Re: Burhoe Inspired Room Flooder

Post by Cressy Snr »

When you build your own speakers, it takes a great deal of time and effort to develop them to the finished state; ask Colin, Mark, Scott or young Chris!

It is not "constant" fiddling and has nothing to do with preference or mood. There is no science to audio appreciation; the only science is in the design and testing of the reproducing equipment. After that, development moves into a different phase, which I would call the "voicing" of the product.

Voicing involves not only your own choices, but also the opinions of people, whose ears and judgement you trust. My normal panel has three members in addition to myself: one a musician and recording studio owner, one a fellow speaker designer and the other an audio enthusiast like myself, who also happens to enjoy designing and building big open baffles, using a mixture of vintage and modern pro drivers.

Referencing your builds to mainstream products with excessive treble and bass, dialled in as a matter of course, to make them sound impressive in a dem room is the route to sonic disaster and ear damage. The commercial salaried designer is given a "sound" to build to, by the marketing department, a sound that they think will sell to the punters. Anyone with half a brain who listens to commercial designs can see that philosophy in action. The designer might think his/her product sounds like a bag of spanners, but they have to play the politics if they want to keep their job. There is no longer room for the artist in the world of commercial speakers.

I don't give a stuff how good a hi-fi is, you CANNOT reproduce the live experience in a living room. Again I ask the question: even if you could, why on earth would you want it in a home environment? If I want the live experience I go to a venue and see the band. I absolutely don't want the band showing up in my living room. What I do want in my living room, is the sense that a musical performance is taking place. Invisible musicians are not something we find in real life. So to maximise the illusion we have to be able to engineer out any sense that we are listening to a recording and we do this by listening, noticing when things are not quite right, making adjustments, then seeing if we have gotten any closer to the music itself.

That is what I'm doing at the moment with my speaker designs. I am not fiddling! It is possible to engineer your designs so that you get the sense of a musical performance taking place. I have got to that sense of a performance, by doing an abstract science thing and reducing the treble level, using a calculated resistor value, combined with the empirical listening method, AFTER the really big, main science bit was got out of the way, viz, the omnidirectional, quarter wave resonator/horn hybrid concept and its associated calculations and software simulation. That's how the process works!

I put up what I'm doing to show that process in action, warts and all. Not many others do that, they are happy to build and keep the process to themselves, showing their finished article at Owston, where it either sinks or swims. I don't blame them TBH, because the amount of crap I've had to put up with from some people since I started this omni business, has made me wonder why I opened my mouth. But I keep going as it's fun, keeps me off the streets and out of mischief.
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Cressy Snr
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#32 Re: Burhoe Inspired Room Flooder

Post by Cressy Snr »

And whilst we're on the subject; this is not amateur, dilletante fiddling around. This is actually a serious speaker project that is trying to answer a specific question; that of how to interface a transducer with a normal, domestic living environment, as opposed to an audiophile's listening room.

Both the Metronome design (2006) and the omnis (2016) in their different ways have solved this problem, as plenty of happy builders/owners of the Metronome, across the world will tell you. I have gained nothing financially from these designs but it's nice to know that other people appreciate your work and the additional work of those generous people (Scott and the guys at Planet10) who helped me to scale up the concept.

You CANNOT exclude the room from the loudspeaker design equation, you either make a serious effort to address this, and make a speaker that is easily placed, plonk and play, and accessible to the general public or you design in an anechoic chamber and then tell your "audiophile" user to put the speaker away from boundaries, and treat the room with expensive acoustic tiles and bass traps.

You design a loudspeaker to bring the music to your room, not the other way round. You are listening in your room, not the studio or venue. You can't transport yourself there, so why even attempt to do so. It's complete madness.
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chris661
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#33 Re: Burhoe Inspired Room Flooder

Post by chris661 »

Cressy Snr wrote: Mon Mar 19, 2018 12:24 pm When you build your own speakers, it takes a great deal of time and effort to develop them to the finished state; ask Colin, Mark, Scott or young Chris!
Might post up about some little PA speakers I've been working on. 18Sound 6ND430 and a HF horn. Passive crossover, which is something I've never done much before. There was quite a lot of arguments between me, my laptop, and the circuits in front of me before I got something worthwhile.
... and then there was the problem of midrange getting out the ports.

In all, there was probably a solid week's worth of measuring and fettling once the cabinets were built and drivers installed.

Results are worth it, though. They're exceptionally clean sounding, reasonably full-range (low bass is missing), and go staggeringly loud if you happen to drop a few hundred watts in there.
DSJR wrote: Mon Mar 19, 2018 12:01 pm But that's the point - you CAN reproduce the sound of a live unamplified jazz group artificially in a living room if the recording is good enough and the monitors powerful and 'clean' enough
That would require a sound system capable of 1Hz-50kHz+ with >120dB output, and zero distortion while doing it. I've got a good spectrum analysis of a close-mic'd kick drum, which shows 138Hz and 32Hz at the same level, and 16Hz only 3dB down on those.

That's not to mention the fact that you're trying to represent a set of instruments spread across in front of you using two point sources which will interfere with each other in ways that the actual instruments would not.

If you did something like the Grateful Dead's Wall of Sound (ie, one speaker, correctly placed, per instrument), you might start getting close. Nobody, however, will give you the multi-track recordings required to pull that off. You'll also need to re-arrange your pile-o-speakers on a track-by-track basis to get the correct image.

At the moment, we're waving bits of cardboard around using magnets and the fact that it sounds like music at all amazes me. It's never going to be perfect, but I quite like what we can do.

Chris

PS - I might give it a try, though, as the digital mixing desk I have does let me record multi-track, and play back through up to 12 outputs.
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Nick
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#34 Re: Burhoe Inspired Room Flooder

Post by Nick »

That would require a sound system capable of 1Hz-50kHz+ with >120dB output, and zero distortion while doing it. I've got a good spectrum analysis of a close-mic'd kick drum, which shows 138Hz and 32Hz at the same level, and 16Hz only 3dB down on those.
I must just question that, what happened to the range of sounds we can hear? Where did 1Hz and 50kHz come into the requirement. And why is zero distortion required? An unamplified kit in a room would not be listened to at close range. I have listened to jazz band in a hose size room many times, the pub we used to have ran a jazz club in such a space, we did have rock bands in the same space, but Jazz didn’t get to 120dB that often.
That's not to mention the fact that you're trying to represent a set of instruments spread across in front of you using two point sources which will interfere with each other in ways that the actual instruments would not.
So Blumlein was wrong? Stand a upright bass next to a snare drum and tell me again they don't interfere.
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#35 Re: Burhoe Inspired Room Flooder

Post by steve s »

My system makes a good job of reproducing my daughter recordings they sound very lifelike. Very much sounding exactly like her singing

The recordings she has had done at the local recording studios after mastering sound very different though. One occasion I watched the guy compressing her vocal track, he made a nice job of making her sound like any other singer on the radio... but the real life sound went
It's a bit sad, they do it without realising the damage.
I agree with Dave's comments about chasing a live sound, that's been my way too. But can totally understand where Steve's coming from, in his room. Horses for courses ?
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#36 Re: Burhoe Inspired Room Flooder

Post by ed »

Nick wrote: Tue Mar 20, 2018 10:22 am
So Blumlein was wrong? Stand a upright bass next to a snare drum and tell me again they don't interfere.
of course he was wrong, bloke didn't know anything! snigger!

my Bella hums quietly to herself quite often when I'm playing music. Sometimes when I stop playing music she carries on for a moment or two, embarrased. That's not interference, that's mutual respect.

But seriously, two instruments in unison can be quite disturbing whilst mixing..sometimes incredibly destructive. But it doesn't have to be in unison, any relative pitch can interfere. Most classical arrangements wouldn't exist if there wasn't interference. Most rock tracks...don't get me started
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#37 Re: Burhoe Inspired Room Flooder

Post by ed »

chris661 wrote: Tue Mar 20, 2018 9:21 am
At the moment, we're waving bits of cardboard around using magnets and the fact that it sounds like music at all amazes me. It's never going to be perfect, but I quite like what we can do.

Chris
this bit I do agree with though
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Cressy Snr
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#38 Re: Burhoe Inspired Room Flooder

Post by Cressy Snr »

steve s wrote: Tue Mar 20, 2018 10:28 am I agree with Dave's comments about chasing a live sound
That's where he completely misunderstands what I'm talking about. He wants live sound, so do I.
Where me and him part company is on the basic question of sound level. Why does recreating a live sound, have to mean it has to be loud? That is all I'm trying to say, but as per bleedin' usual...... :roll:

I think it is all relative and entirely dependent on the size of the space containing the speakers, and you have to design your speakers with that space at the forefront of your mind. Big speakers - big rooms, small speakers - small rooms; laws of physics and all that.

There's nothing radical in what I'm trying to achieve, so maybe someone could take me quietly aside, maybe by PM, and explain what is the fatal flaw with the pragmatic approach I take to speaker design. I'm not after approval, I really am genuinely baffled and would like to understand.
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Nick
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#39 Re: Burhoe Inspired Room Flooder

Post by Nick »

I am a bit confused here Steve
what is the fatal flaw with the pragmatic approach I take to speaker design.
I am not sure anyone has said there is a fatal flaw in your approach.

All I was questioning was your assertion about what it was not possible to do with loudspeakers in a room. My point was I could ring a few people, pass some cash on and I could have a small Jazz band playing in my room. The walls would not fall off and no one would die, so I dont see why its not possible to get a pair of speakers (of some sort) to do the same thing with a recording of a small Jazz band.
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#40 Re: Burhoe Inspired Room Flooder

Post by Cressy Snr »

OK Nick, point taken. Maybe I've not heard a big enough system.
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#41 Re: Burhoe Inspired Room Flooder

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Cressy Snr wrote: Tue Mar 20, 2018 5:40 pm OK Nick, point taken. Maybe I've not heard a big enough system.
Or a small enough Jazz band.
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#42 Re: Burhoe Inspired Room Flooder

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Nick wrote: Tue Mar 20, 2018 10:22 am
That would require a sound system capable of 1Hz-50kHz+ with >120dB output, and zero distortion while doing it. I've got a good spectrum analysis of a close-mic'd kick drum, which shows 138Hz and 32Hz at the same level, and 16Hz only 3dB down on those.
I must just question that, what happened to the range of sounds we can hear? Where did 1Hz and 50kHz come into the requirement. And why is zero distortion required? An unamplified kit in a room would not be listened to at close range. I have listened to jazz band in a hose size room many times, the pub we used to have ran a jazz club in such a space, we did have rock bands in the same space, but Jazz didn’t get to 120dB that often.
That's not to mention the fact that you're trying to represent a set of instruments spread across in front of you using two point sources which will interfere with each other in ways that the actual instruments would not.
So Blumlein was wrong? Stand a upright bass next to a snare drum and tell me again they don't interfere.
Nick,

We can detect extremely low frequencies just fine, albeit in our bodies instead of using our eardrums. There are home-theatre nutters reporting many interesting things happening in movies below 10Hz, and they've got the measurements to back it up.
The 50kHz extension was just an estimate of how high up a cymbal might go. If you want to properly reproduce that in all it's glory, then I suspect extension past 20kHz might be required. Some people have quite a lot of hearing ability past the usual 20kHz limit, though they are fairly few.

I would expect the zero distortion argument to be obvious. My reasoning is simple: the signals that go in should come out again as close to the original signal as possible. Distortion of any kind (harmonic, frequency response, time, etc) would introduce deviations from the original signal, and should be eliminated if we really want to produce a faithful reproduction of the signals in question.

With regards to the interference, consider this:
Lets say a single mono source in front of you will give you a flat response at your eardrums.
Two seperate sources attempting to be mono will have two arrivals at each ear drum, based on time-of-flight differences around your head. The result is comb filtering above a couple of kHz. The result of that is that the tonality of a signal will change according to whether it's panned centre or hard to one side.
I suppose you could argue the Haas effect comes in and sorts out the second arrival, but I'd argue that you're still making the brain do extra work to put together the stereo image, which wouldn't be necessary if the instrument was in front of you.

There's also the way the speakers interact with the room - the reflection times will be very different when you compare a pair of speakers vs a single speaker in the centre.
So, I don't think it's possible to get two speakers playing stereo to properly reproduce something that's meant to be straight in front of you. It's not the fault of the speakers, it's the problems inherent in stereo placement.

I'm curious about how you measured the SPLs you report. A simple SPL meter, even set to fast, might have a time constant of 100ms, which is nowhere near fast enough to properly track a particularly loud hit of a snare drum, for example.
A test was done here, involving guns: http://forums.prosoundweb.com/index.php?topic=161119.0

For what it's worth, I wouldn't expect live jazz to get to 120dB, even for the briefest of peaks, but limiting a hypothetical system to exactly one genre of music doesn't sit too well with me - a HiFi system should be able to play anything and sound as good as the recording will allow. Bon Jovi should be allowed on-stage, too.

Chris

PS - we haven't even considered how we might record the live band yet.
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#43 Re: Burhoe Inspired Room Flooder

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Cressy Snr wrote: Sat Mar 17, 2018 9:28 pm One really has to be careful when doing stuff like this, that it does not get overdone,
Oh, not half! :shock:
 
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#44 Re: Burhoe Inspired Room Flooder

Post by andrew Ivimey »

How about .... it's fairly easy to create the SPL of a live band/ orchestra in a living room but it is very unpleasant to do so.

The live jazz band idea is very funny, well it is to me.

I've been listening to mono presentations this week. It began accidentally but I persevered and it has both pros and cons. My brain is amazingly accommodating - my ears just provide access to a source.

N.b. stereo does not mean two channel ( or 5.1) it derives from the ancient greek meaning realistic.

What is real? Objective reality - when do we ever have to come to terms with that!? One of the best books I read on that is called The Social Construction of Reality - one of those titles that say a great deal without ever actually opening the book.

I'm going back to my snug little world of jazz for now and Friday I'm taking earbuds/phone with me to Malta. What will I hear then/There? Amongst other things a mono recording of Kind of Blue.
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#45 Re: Burhoe Inspired Room Flooder

Post by ed »

I posted a flippant response a few items back, I apologise to those who find my flippant comments tiresome, but I guessed the discussion was heading off into the stratosphere......I gave up this malarkey a few years back because I thought I was becoming too serious by responding to arguments/heated discussions that were developing from the pursuit of a hobby......my bad!...I wish I could go the distance.

To add my final two penneth to Steve's original discussion about recreating the live experience.....repeating my mantra about not being able to identify a scored line in a piece of music because I can't identify the instrument in the sound scape in the first place. My premise has always been to identify the instrument first then it's possible to determine what part of the arrangement that instrument is playing..and maybe whether you like it's contribution to the piece as a whole......

The alternative is a wall of sound with no indication of where the individual instruments are and more often than not, what they're playing. This causes me to mention that the 'Bear's' wall of sound is quite the opposite of a wall of sound...it's the amplification of individual instruments to better magnify what's on offer.....should have had a better name for it, should have been pursued imo.

But back to the original premise....my method of appreciation can never be achieved with omnis( as in Steve's set up) as I can't locate the instruments in the first place...so I maintain it's not even started to get close to 'being there' reproduction. This is with some experience of omnis, although not exhaustive.

YMMV.

Diet: the wall of sound may work for the man/woman with one ear.
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