Whoever implemented and experimented with my slicing of lower MF range by 3 channels (Upperbass, Fundamentals, and MF) know how powerful it might be. Changing loading and volume of each of the channels it is possible to write any sound one might wish, well if the one knows what to wish. However, recently the game slightly changed and the Fundamental channel got prominence it did not have before. The game change was the DHT driver in MF.

With 6C33C and 6E5P as the MF amplifier the amplitude of the Fundamentals channel was set to benefit the volume of the MF and it worked great. However, all 6C33C sound in a way the same and all 6E5P sound in the way the same. It is not the they sound bad but change from one tube to another did not change the character of MF, so the Fundamentals channel cared about the balance between the volume of MF and Fundamentals.

With the DHT tubes each tube is pretty much own character and the Fundamentals channel not only compliment the  vile setting on MF but also do some very-very interesting compensation, or better to say filling, for the MF. I would say that in some instance it might be +/-  of whole 2dB that Fundamentals channel might output to get the things right. Do not forget that my Fundamentals Channel is very surgical, works in very narrow band (600-1000( and has first order high pass and second (?) order lowpas with one single 6E6P driving Vitavox S3 driver.

What I need at this point is away to calibrate the Fundamentals Channel VERY precisely with 1/4dB resolution. It might be damn costly…

Romy the Cat wrote:

Dominik wrote:

You probably decline this option, because this horn is from plasctic ( You can take carbon horn also). Polish autotech make Iwata 300 for me. You Can order from them what You want.

Yes, the Iwata horns are good as they have right horizontal vs. vertical proportion for my case but the Iwata profile optimized for HF, something that I do not need. Still I am looking into some kind of derivation of Iwata profile – I need to look into this further. My leading idea is 18-cell horn by in my custom shape…

el`Ol wrote:

Probably too "budget", but they have almost everyting. http://stores.ebay.de/Stereo-Lab

Thanks, el`Ol, the Stereo-Lab do juts fast opening horns – I do not need then for Fundamentals Channel. Also they do spherical horns and I very much would like to stay away from spherical for this given lower MF Channel.  Might be I will consider an oval shape - it is hard to do it in mass, however….

jessie.dazzle wrote:

When you get those cat paws on a 170-180Hz horn, you'll likely try listening to it while letting it cover more than just 600Hz of bandwidth (letting it run up higher than 1000Hz)... There is a possibility that one day you'll decide this is in fact the way you want to use it, in which case you might wish you had gone with a round horn.

I do not think I will. I will most certainly do not need it to go over 1000Hz, why would I? It is very much not my objective. All the I would like to do it to give to Fundamentals Channel some room from the bottom to breathe as I fill it is a bit too contortionistic now.

jessie.dazzle wrote:

You do have the space for it, but it would require that you move the Injection Channel up; since it is running at -12dB, this should not upset the perceived height of the image.

This is not my objective as well. If anything I would love to find a way to move the Injection Channel down, closer to MF and HF channels. I do not how to do it, though…

jessie.dazzle wrote:

The new, larger round horn could be mounted not under, but on top of the arm currently supporting the 250Hz horn. Running a physically high-mounted 170-180Hz channel up into lower mid-range, one would logically be concerned about upsetting the perceived height of the image; In my experience (I use this configuration), the image does not so much move up, but rather increases in scale and opens up. This, to me is more like what I hear in a concert hall or theater; such a configuration does require a minimum 12-foot listening distance, which appears possible in your case. You could get some idea of the effect by running your high-mounted Injection Channel at -0dB.

Possible, but this would require moving my Injection Channel up – a big “no-no” in my book. You report that “image does not so much move up”  - it is not what I experienced in my old room. What crossover point and type of filter you use for Fundamentals Channel LOW pass filter?

jessie.dazzle wrote:

To avoid vignetting caused by the new 170-180Hz horn, the Injection Channel enclosure could be inverted so that the driver is at the top.

I am planning to avoid vignetteing by using non-spherical horns. No matter what it will be the horn high won’t be higher than 17-18”, in fact I would like to keep it 15”-16” at best if possible. If you calculate the surface that is needed to write 170-180Hz horn with 15” then you will have a good near 160 degree horn. For very much LOWER MF…. I see no problem with that. I did not those horns designed but I do not see what it shall not be made. If I knew what driver to use then I would do it. I would love S2/S3 to be able to handle the job as I love their lower knee but they are not good for pushing them too much lower.

jessie.dazzle wrote:

You'd likely also have to increase the footprint of the chassis to insure stability (extend the base plates by bolting on square section metal tubes).

Dominik wrote:

Maybe they can do it something for You: http://chaudioroom.com/Lportal.html

Romy wrote:

"...I will most certainly do not need it to go over 1000Hz, why would I? It is very much not my objective. All the I would like to do it to give to Fundamentals Channel some room from the bottom to breathe..."

Three reasons:

1) To try high passing your upper-MF channel (S2 > 400Hz horn) above the 1250Hz secondary resonance assiciated with the plastic-suspended diaphragms of the S2 when used in wide bandwidth configuration. If I understand correctly, you currently use these diaphragms and run the driver from 10.5KHz down to 1KHz.

2) To try unloading the lower end of that same channel which, again if I understand correctly, in your case is currently covering more than three octaves. Reducing that range may in practice not turn out to be desirable, but I would have thought you'd be curious.

3) To simply evaluate which driver/horn combination is best suited to reproduce the 1-1.5KHz range.

"...What crossover point and type of filter you use for Fundamentals Channel LOW pass filter?..."


Above image shows response of S2 drivers with metal-suspended diaphragms.

Concerning perception of the vertical center of the sound image; no, we do not want the perceived center to be located somewhere in heaven or hell, but the view of most people who practice audio is that it would be desirable to produce the entire audible spectrum from left and right points as close to ear-level (purgatory?) as possible. In answer to that, I would like to put forth the following idea or sort of hypothesis:

First, what is the objective of audio? For me, ideally it is the selective recreation of an event according to and in reinforcement of the artist's original intention, as well as what I myself might decide to "keep" from that event, had I witnessed it live (the more thoroughly the demonstration integrates and allows me to grasp concepts as concrete wholes, the more I will be engaged; the more those wholes correspond to my view of what life should be, the more I will keep). When reproducing live events witnessed in physical space, that space too must be taken into account.

With the exception of small clubs where we might hear a jazz trio, when we listen to live music, we rarely find ourselves on the same plane with the musicians; we are usually looking down on them. This is not a chance occurrence; when seen and heard from this angle, the depth of the space, in both vision and sound, are more clearly revealed.

Look at the image below showing the layout of an orchestra from the point of view of the listener; this is two dimensional data that successfully depicts a third dimension, that of depth. It does this by using both the horizontal and the vertical (if it were a more accurate drawing, it would make better use use of relative scale and relative intensity). Notice, there are instruments located at the top, middle and bottom of the image. I'm not trying to be silly; realize that sight (light) and sound (pressure) are first perceived as binary, two-dimensional (up-down/left-right) sense data; from this, our brain extrapolates the third dimension; depth.



Yes intensity (amplitude) and cast shadows (masking) play a part, but a really convincing illusion of depth is difficult without making use of the vertical axis. I think the depiction of depth in audio relies on the vertical; I think we are using it and I think we are not acknowledging it... It is what gives some mono recordings a semi-convincing illusion of depth. 

Absence of the vertical axis is the principal limitation and resulting frustration associated with headphones.

jd*

Sorry, I do not share your sentiments with those 3 reasons. Below are my reasons.

jessie.dazzle wrote:

Three reasons: 1) To try high passing your upper-MF channel (S2 > 400Hz horn) above the 1250Hz secondary resonance assiciated with the plastic-suspended diaphragms of the S2 when used in wide bandwidth configuration. If I understand correctly, you currently use these diaphragms and run the driver from 10.5KHz down to 1KHz.

My MF channel is crossed well above secondary resonance – at  3200Hz

http://www.goodsoundclub.com/Site_Images/6-Chennal_Melquiades_DSET_Amplifier_Rev3.jpg

I get my 1000Hz by gliding the filter-declining slope of the secondary resonance

jessie.dazzle wrote:

2) To try unloading the lower end of that same channel which, again if I understand correctly, in your case is currently covering more than three octaves. Reducing that range may in practice not turn out to be desirable, but I would have thought you'd be curious.

 I do not feel a need to unload lower end from my MF channel. I did listen the naked MF channel extensively and in my view it does fine and do not need any crossover modification.

jessie.dazzle wrote:

3) To simply evaluate which driver/horn combination is best suited to reproduce the 1-1.5KHz range.

So we are taking about 500Hz that might be handled by ether MF of Fundamental channel. It might make sense mathematically and looking at graphs but in all practicality it unfortunately doesn’t works this way. In the 1-1.5KHz range I have pretty much 4 channels work together MF, Upperbass, Fundamentals and Insertions. Do not forget that with exception of upper knee of Fundamentals Channel they all are first order, with a lot of overlap and acoustic inner-modulations. Measurements-wise it if flat of course but in reality I never was able to set what I call proper sound by measurements. I do the following. I set the only Upperbass and MF flat by measurements and it will have a little dip of an octave wide around 800Hz. Then I run the Fundamentals all the way up until the peak of the Fundamentals response just touched and very slightly dent the bottom of the 800Hz dent. Then I begin to listen and set by hearing the level of Fundamentals in order to get the MF richness but not too prominent. The rule is that is that I need juts to recognize that Fundamentals channel is engaged but I shall not have it prominent in any auditable moment. A trombone sliding across it’s range and mantling the almost fixed vertical image is good indication that my Fundamentals are not too hot. I said “almost” because I personally feel that that in my old room the right amount of Fundamentals was when in the very top range the Fundamentals shall very-very-very little to shift the image up. It was very extreme nearfiled however and the degree to which it took place was not annoying in my view, particulary after I went DHT for MF.

jessie.dazzle wrote:

Concerning perception of the vertical center of the sound image; no, we do not want the perceived center to be located somewhere in heaven or hell, but the view of most people who practice audio is that it would be desirable to produce the entire audible spectrum from left and right points as close to ear-level (purgatory?) as possible. In answer to that, I would like to put forth the following idea or sort of hypothesis: First, what is the objective of audio? For me, ideally it is the selective recreation of an event according to and in reinforcement of the artist's original intention, as well as what I might myself decide to "keep" from that event, had I witnessed it live (the more the demonstration corresponds to my view of what life should be, the more I will keep). When reproducing live events witnessed in physical space, that space too must be taken into account. With the exception of small clubs where we might hear a jazz trio, when we listen to live music, we rarely find ourselves on the same plane with the musicians; we are usually looking down on them. This is not a chance occurrence; when seen and heard from this angle, the depth of the space, in both vision and sound, are more clearly revealed. Look at the image below showing the layout of an orchestra from the point of view of the listener; this is two dimensional data that successfully depicts a third dimension, that of depth. It does this by using both the horizontal and the vertical (if it were a more accurate drawing, it would make better use use of relative scale and relative intensity). Notice, there are instruments located at the top, middle and bottom of the image. I'm not trying to be silly; realize that sight (light) and sound (pressure) are first perceived as binary, two-dimensional sense data; from this, our brain extrapolates the third dimension; depth. Yes intensity (amplitude) and cast shadows (masking) play a part, but a really convincing illusion of depth is difficult without making use of the vertical axis. I think the depiction of depth in audio relies on the vertical; I think we are using it and I think we are not acknowledging it... It is what gives some mono recordings a semi-convincing illusion of depth. Absence of the vertical axis is the principal limitation and resulting frustration associated with headphones.

I personally prefer do not have center imaging as close to ear-level. I prefer to have center imaging elevated up and I like to listen with slightly raised my head. It makes discipline impact and put Sound in position of authority. The vertical axis is fine, I am not against it but I think that you are taking not about the vertical axis but rather about radiating surface. I wrote about it manse times – larger radiating surface when Sound comes not from a single point but from a large “cloud” is much interesting configuration. Unfortunately, due to the physics of our hearing (the position of ears) we can increase the size of the cloud only in vertical plane.

"...My MF channel is crossed well above secondary resonance – at  3200Hz... I get my 1000Hz by gliding the filter-declining slope of the secondary resonance..."

I know this... What I'd really like to see is that by further unloading the lower end of this channel, you'd once again try using the all-metal diaphragms. I'll let you figure out where I'm going with this (hint; injection channel).

About the 500Hz that might be handled by ether MF or Fundamental channel: Yes, I admit, at first glance it does seems like small potatoes, but at this frequency range, an additional 500Hz represents half an octave. More importantly, an S2 with a 180Hz horn working in this range simply must be heard; my guess is you'd want that horn doing the job.
 
"...I think that you are taking not about the vertical axis but rather about radiating surface..."

I'm talking about radiating surface(s) distributed along the vertical axis, in the interest of conveying depth. My point is that we perceive depth in audio in large part due to the relative vertical relationship of sounds.

"...I wrote about it manse times – larger radiating surface when Sound comes not from a single point but from a large “cloud” is much interesting configuration. Unfortunately, due to the physics of our hearing (the position of ears) we can increase the size of the cloud only in vertical plane..."
 
Our ability to locate the origin of a sound to the left or right is superior, but despite the horizontal disposition of our ears, we are able to perceive and differentiate between sounds coming from above and below (hence the fear of a perceived vertical image center in heaven or hell). We regularly make use of this faculty to recreate the illusion of depth in audio, and we just as regularly deny it.

Reality or illusion, the concept of depth automatically invokes a minimum of three, non-collinear points in space.

jd*

somehow i missed that moment in macondo development when you introduced S3 as a low mid driver so this came as a surprise to me - what i remember is that you didn't write so favourably of S3 back in 2004 due to its ceramic magnet. but it's good to see that you find a good use of it as it's obviously so much cheaper than S2 these days, if you are lucky to find a pair.

what is the final horn & crossover frequencies you've settled down, and what are the realistic thoughts on the lowest crossover frequency S3 can handle in the domestic conditions in the dedicated le cleach horn, say 200hz or little less, with very low power into it (not more than 2-3w). i'm asking because i'm seeking for a driver for 300-1500 (or so) range ideally, it seems that apart from usual suspects like JBL 2482 or EV DH1 there's not much left, and i'd love to see S3 able to dive just a tiny bit lower than it seems it  normally can.

upper midrange is another topic but out of curiosity, do you still find S3 as handycaped at that range as you've thought back in 2004? i assume if it wouldn't be, than there would be no any basis left for S2 hype....