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Nearfield Loudspeaker Placement

 
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hector smith
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Joined: 23 Oct 2012
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Location: Bettyhill

PostPosted: Thu Oct 25, 2012 8:09 pm    Post subject: Nearfield Loudspeaker Placement Reply with quote

Hi.
I am looking for advice on speaker placement. Nearfield
I have a pair of 104aB's , and I am finding it hard to ESTABLISH EXACT `FOCUS' on the second speaker. with the drive units being offset from the cabinets I am looking for an easy way around this. any help would be great .
Thanks, Hector.
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speakerguru
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PostPosted: Fri Oct 26, 2012 8:20 am    Post subject: Re: Nearfield Loudspeaker Placement Reply with quote

hector smith wrote:
.... `FOCUS' on the second speaker.....


Not sure what you mean by this. Can you elaborate or paraphrase?
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hector smith
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Location: Bettyhill

PostPosted: Fri Oct 26, 2012 8:09 pm    Post subject: Nearfield-Placement. Reply with quote

http://www.nsmaudio.com/Nearfield-Placement.
Hi,
If you use or have heard of this method, you will not have to look at the link, it's how its achieved the holographic sense of depth .
My problem is with the 104ab's, having the drive units mounted on the left hand side which in turn is making it hard for me to achieve the exact same angle of axes on the second speaker, I have used this method now for a few year, and focus can sometimes be a hit or a miss .
I am just praying that someone with 104's that also listens to Nearfield. will see this and it wont be double Dutch.
And also . pleas,

Speakerguru.

I think you might be the man,,,,,
I have used my +&- to tweak the rear sound stage back into centre on the odd occasion, with good results.
but can you explain to me what there intended function is,
If it's to balance one side or the other, what happens if both are at the same, like left and right both set to +.
THANKS
,Hector.
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audiolabtower
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PostPosted: Fri Oct 26, 2012 10:29 pm    Post subject: Reply with quote

I used to have the 104aB and do not think you were supposed to have different settings on each speaker, since pinpoint stereo needs good matching between the pair. One forward and one backward response is unlikely to help good imaging? The control was meant to compensate for either dull (very heavily damped) or bright (hard surface) rooms, but in good rooms always in the centre position. I suppose you could turn both up for dull recordings and down for glaring recordings but might get fed up rushing to the speakers each new cd. Smile

I used them in the BBC style for low colouration speakers, near equilateral triangle for speakers and listening position, speakers toed in to almost face the listener, or cross just in front, away from back wall a distance greater than the stand height, a greater distance again away from the side walls.
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hector smith
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Location: Bettyhill

PostPosted: Sat Oct 27, 2012 4:44 pm    Post subject: Reply with quote

Wat's a ''cd''.
I only like vinyl , its got a much better sense of depth and separation between the front and rear sound stage with the speakers in the placement that I have in use .
cd is allot flatter and two dimensional in comparison .
I often do a like for like test cd-v's-vinyl, to let people hear what can actually be achieved and especially with Nearfield speaker placement the difference is incredible.
Now don't all of you digital heads get your defensive boxing gloves on, I am not interested. I have travelled around for years , just to hear the sound that Jo Blogs was reeding about. and often I would ask to hear what the new age had brought us and to be honest
I think we are going backwards.
The last time being, In a shop in Glasgow, Stereo Stereo. I traveled 400,mile in all.To go and purchase a cartridge for my turntable and maybe listen to something while I was there .
when I arrived at the shop and said to the man, ''that I was looking for a cartridge'' He replayed '' We don't sell ink sunny'' .
MMMMMMMM Good start.
once establishing that he had nothing in the shop that was suitable, I asked ''did he have anything set up in a room that I could listen to''
He huffed and puffed then led me to a room, one with which I was very familiar with. over the years I had spent countless hours in said room, a proper education.
We walked in and i saw. well not what I expected . no lp12. or any turntable. He said it's a thing of the past sunny'', ''you don't get better than this''. then went on to boast about how expensive it was. comparing it to richersounds.
I just kept my £800 and left before the wallpaper fell of the wall.
which looked imminent..
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proffski
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Joined: 22 Aug 2003
Posts: 1297
Location: Tewkesbury UK

PostPosted: Sun Oct 28, 2012 12:01 am    Post subject: Re: Nearfield Loudspeaker Placement Reply with quote

hector smith wrote:
Hi.
I am looking for advice on speaker placement. Nearfield
I have a pair of 104aB's , and I am finding it hard to ESTABLISH EXACT `FOCUS' on the second speaker. with the drive units being offset from the cabinets I am looking for an easy way around this. any help would be great .Thanks, Hector.


I think that you have a problem with your cognitive realism transducers.
The obvious factor you firstly overlooked is the transductive quantum Sokal transducer boundary coherer.

The interplay between the humdinger and the baretter would have produced a severe kink in your probability anomaly index, the repercussions on your grasp of the time space continuum would have been severely distorted beyond any hope of hyper-spacial inversion.

In order to achieve holographic laser-like focus with your second drive unit would need the recalibration of every single molecule of internal foam damping to within the diameter of one foam molecule at the ambient temperature of 34° on the Réaumur scale, I am of course reassured that you realise that this can only be achieved during a full moon whilst wearing a thong and singing the Thelurian national anthem backwards, a task easily undertaken by a four year old child physics prodigy, so you would find it quite easy.

Once the calibration is complete all that remains is to set the reality threshold to -0dB with reference to the isotropic free field response using a Smith chart. You must take into account the positron beam skewing the polar response and pattern relative to the influence of the solar flux as well as VLF communication frequencies used by Russian submarines, tricky!

This covers the very basics, if you wish to follow the entire tuning procedure which I assure you will pay omnipotent rewards you read Impostures Intellectuelles from start to finish and your education will be almost complete. Knowledge after all is power!

Something along the lines of P=work done per chosen unit of time QV/t = IV.
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man standing in a bucket and trying to lift himself up by the handle.
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speakerguru
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Joined: 18 Nov 2005
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Location: Green Hut, Tovil

PostPosted: Sun Oct 28, 2012 8:03 pm    Post subject: Re: Nearfield-Placement. Reply with quote

hector smith wrote:
.....I have used my +&- to tweak the rear sound stage back into centre on the odd occasion, with good results.
but can you explain to me what there (sic) intended function is....


In that era, reducing "midrange colouration" was the holy grail of hi-fi, as advocated by the BBC and highly influential reviewer Angus McKenzie. There was a Rogers/BBC speaker which was very much in favour at that time because of low "midrange colouration". This was achieved in part by having a reduced midrange response. Models 104 and 103 did the same. The 104 being the first reference series KEF wanted to offer a flat frequency response as well. Hence the contour control. It had a wide 1dB midrange attenuation in the "0" position and was flat on the tweeter axis in the "+1" position.

Re room positioning try reading "Sound Reproduction, The Acoustics and Psychoacoustics of Loudspeakers and Rooms" by Floyd E. Toole.
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clubsport911
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Joined: 26 Aug 2012
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Location: Cheltenham, UK

PostPosted: Mon Oct 29, 2012 1:32 pm    Post subject: Reply with quote

I'll see your "cognitive realism transducers" and raise you

Follow this link. It was create by my old company - Rockwell Automation...

I used to show it at the beginning of every sales training session - the look on the people faces was priceless.

http://www.youtube.com/watch?v=RXJKdh1KZ0w
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clubsport911
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Location: Cheltenham, UK

PostPosted: Mon Oct 29, 2012 1:34 pm    Post subject: Reply with quote

Quote:
It had a wide 1dB midrange attenuation in the "0" position and was flat on the tweeter axis in the "+1" position.


Interesting.... how would I do this on 105/3's ?
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proffski
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Joined: 22 Aug 2003
Posts: 1297
Location: Tewkesbury UK

PostPosted: Mon Oct 29, 2012 2:56 pm    Post subject: Reply with quote

clubsport911 wrote:
I'll see your "cognitive realism transducers" and raise you Follow this link. It was create by my old company - Rockwell Automation... I used to show it at the beginning of every sales training session - the look on the people faces was priceless.
http://www.youtube.com/watch?v=RXJKdh1KZ0w


Absolute classic, I cannot wait to try it on our 6th form physics students as their new project... Proceeded by introductory video!
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I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill
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TL 200
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Joined: 27 Jul 2009
Posts: 141
Location: Emmer-Compascuum The Netherlands

PostPosted: Mon Oct 29, 2012 3:42 pm    Post subject: Reply with quote

Quote:
with the drive units being offset from the cabinets I am looking for an easy way around this. any help would be great .

Perhaps you buy a second pair so you can "mirror" the cabinets.
Much to your surprise (i think) you'll find out that you have two mirrored pairs then. You might even pile them all up or try making a semi-cirkel with yourself put in the centre of it.
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speakerguru
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Joined: 18 Nov 2005
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Location: Green Hut, Tovil

PostPosted: Mon Oct 29, 2012 11:17 pm    Post subject: Reply with quote

clubsport911 wrote:
Interesting.... how would I do this on 105/3's ?

104 is a 2 way using a tapped inductor. 105|3 is a 3 way so you can't use the same method. Maybe resistors like on the Cantata?
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clubsport911
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PostPosted: Tue Oct 30, 2012 10:31 pm    Post subject: Reply with quote

I thought the 105/3 was 4 way ? Anyhow I guess a low value resistor in series with the drive units would have the same effect.
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speakerguru
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PostPosted: Thu Nov 29, 2012 9:00 am    Post subject: Re: Nearfield-Placement. Reply with quote

speakerguru wrote:
... There was a Rogers/BBC speaker which was very much in favour at that time because of low "midrange colouration"...

I just remembered it was the Spendor BC1, nothing to do with Rogers. Sorry for any confusion.
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audiolabtower
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PostPosted: Thu Nov 29, 2012 7:15 pm    Post subject: Reply with quote

I think it is fair to say the BC1 revolutionised the speaker industry by showing a moving coil design could approach electrostatic performance in terms of accurate stereo, depth, and midrange colouration, was often used as a reference by other speaker designers for midrange and treble performance. It could even have somewhat been an inspiration for the introduction of the Reference series.

I remember my 104(and aB) manual showing the 0 position as "flat" with + and - showing 2dB boost and cut in the midrange, and saying the "flattest" response was in the reference position. The adjustment curve was a little different from the "BBC" dip which tended to be around 1-2 kHz energy since this gave better depth perception with the bextrene cones of the day. Dudley Harwood maintained the dip in his Harbeth designs and told Alan Shaw it was to minimise a colouration in the polyprop cone - amazing admission direct from the "inventor".

I had the 104aB and swapped for the first Harbeth, which had better depth and transparency but not the best tweeter in the 1in Audax, then swapped the Harbeths for BC1s which by then were the higher flux ferrite magnets with higher power coils and lined port tubes, and frankly they were better overall than both. I then got 105s as the closest I could find to the BC1 stereo, depth, midarnge/treble with better bass and higher output.
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