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In the Forum: Horn-Loaded Speakers
In the Thread: Deep End DIY - Australian take one Macondo.
Post Subject: Thanks for your input...Posted by anthony on: 4/5/2017
 Romy the Cat wrote:
Here I share some thoughts about what you have shown. I will share only critical and warning thoughts not because I have nothing but critiques. All nessesary compliments for your planning come as a default and I do not think you posted it here to hear salutations but you rather prefer to hear warning from the people who have done it. Jessie, if you are around there then you would be a good person to comment about your experience regarding this project as you have done something similar. Anyhow here are some of my comments in no particular order. 
 
1)      I do not know why, and I never thought about it unit I have done my project but I am very sensitive to visual aspect of what is located juts behind the Macondo frame. As I look at the Macondo horns fixture with the tweeter projects to the main frame it look sand feels very elegant and symmetrical. For some reasons I do not like to see behind the frame anything that screw up the elegance and symmetry. This is why I do not like to put Milqs amplifiers behind the Macondo frame. I did try is multiple times and it did not feel good to me. I personally much prefer when the amps not behind the frame but slightly on the side of the frame. It just makes to me the whole playback configuration more balanced. Do not forget that with Macondo configuration you will have the speaker’s stage at ~14-16 feet minimal. With upper-bass horns of 36” you will have a LOT of empty space between the speakers… Saying it I need to admit that it is just me and your mileage might wary, it is not to mention that your amps is located very low and you might not even see it,  
 


Yes, the warnings of potential problems and suggestions for improvement are really what I would like to hear.

It is interesting that you have mentioned the symmetry thing in regards to what is behind the horn stack.  I have oscillated in what I wanted in regard to where the amplifers sit and how much of them I want to see or don't want to see.  When initially thinking about building the DSET I thought that it would be nice to see the glow of the tubes in all of their glory and to really show them off, but over time that idea has mellowed.  It mellowed especially once I had the fullrange Melq prototype in the listening room and found myself distracted by its glow when sitting in the dark and then thought of what two dozen glowing tubes would do compared to the four that I had in the room at that time.  So now I don't want to see all of the tubes while listening and think I could be quite happy if I did not see any of them from the listening chair...perhaps seeing a few and glimpsing some others is kind of like a tease...something held back...and is a worthy compromise.

In the end I am constrained by more practical concerns regarding the layout of components in the amplifier.  The OPT's need to be at the front surrounding the recess that accepts the main pillar of the horn stack and I would prefer the interconnect to come in at the back so in the end I chose to "turn around" the tubes so that they are set opposite to your configuration i.e 6C33C closest to the listener and the gas regulators furthest away.  I like this layout and it helps with the 'tease' where the tubes are a little on show but you have to make an effort to find them all.  Another physical constraint is the height of the first bends in the main pillar of the horn stack.  The speaker cables exit the case in the recess and that recess needs to be aligned for maximum room in relation to the horn pillar which in turn sets the height at which the amplifier sits.  I do not have much wriggle room here so I can make the amplifier sit higher but realistically it can be no lower in an effort to hide the tubes altogether even if I really wanted to do that.

I do not mind a speaker system dominating the aesthetics of the room as these will do, but what I can't abide are components and cables and crap spread from Arthur to Martha on the floor and the room starting to resemble a hoarders lair.  If it is big, it has to be tidy and contained and a significant part of that for me is getting the amplifiers on the horn stack and immediately eliminating most of that 'mess' of cables.  From that train of thought the idea of separating the amplifier from the horn stack cannot be entertained.

One thing that I have not mentioned is that the amplifiers will be mirror pairs so what is on the inside of the left mono is also on the inside of the right mono.  For my own sensibilities this was essential.

 Romy the Cat wrote:

2)      I do not buy the idea of tube woofers, I never did it with the guy from Mexico and I still do not like it. First of all the harnesses that you depicted will not work. This will be very heavy and you will need some kind of heavy duty vertical poll to hold the whole stack together. The ability to slide the individual woofers is a great thing but why not to do it in rectangular boxes? If you are planning to use the woofers that I used then you would need at least 1” foam in there – you will not have space in those small 10” tubes. If I did it and to have the objective to time-slide the woofers I would make 4 rectangular sections with 2 drivers each and would make the front baffle let say 5 degree angle. They I would be able to fulfill any configuration by sliding and rotating an individual section. Well, I do think that to have 4 dual driver section with straight baffles will be fine as well… 


I will build some wood boxes to test against the steel cannons, but there are two main reasons why I a prefer the steel tubes at this stage:
  1. There is less work for me in the steel construction.  This Macondo/Melquiades build has been going over two years now and I really want some results.  With the wood box I would be compelled to build them and finish them and paint them which is a lot of time that I can put elsewhere.  With the steel construction I have them laser cut, a guy I know will weld them for me (my welding is amateur at best) and I will have them powdercoated by someone else and the colour match will be perfect with the power supply and amplifier cases.  All I have to do is drill and tap some holes in steel which I can do over the course of a weekend. 
  2. I have designed the 2 driver wood boxes and when I stack them and put them next to my horn stack in CAD they are just not as pretty as the steel tubes and actually detract from the aesthetics in my opinion.  The main problem is the width of the front baffle and the long straight sides that seem to not compliment the horns.  They are different to your woofer towers Romy in that the drivers have no vertical separation between them and I am limited to a 1m (40") depth so the baffle needs to be wider than yours.  My wood version looks more bloated and oversized by comparison.


 Romy the Cat wrote:

    
3)      A missing channel. If you have your playback in a small room and you will be lucky to have your upper bass horns at very active spot of your room then you will be fine with the configuration you shown. I had it what I live in Boston and my upper bass horns work very comfortable at 95 Hz and they were in active room zones. If your room is larger and if the upper bass horns are not at hot spot then you will have 130Hz of it this upper bass horns. If you use my woofer then your cross them over 100Hz will be a bit problematic. My woofers are very interesting. If you use it at 100Hz then they are more at crap side. You need to cross them much lower. Then you begin to multiply them. As you pile 4, 5 or 8 of them you have a substantially more interesting results. 8 of them you will be able to use even at 100Hz but only in small room and only with very lightly loaded amplification. The woofers have own signature but very pleasurable and much dominated by second harmonics. I tend to love. I can hear instantly that my woofers are in playback and I agree that they are “coloration” but this “coloration” agrees with me. So, you might consider to have a dedicated midbass channels but to do it you your to take your room and your spear placement into configuration. You do not know it yet and then you do not k now the crossovers, gain and the OPT from app you might need. So do not rush as at this point not everything might be predicated. What I would adviser is to buy 2 of my woofer and play car audio game with them, trust me, it is very educational.


This is excellent information Romy.  I have been worried about crossing the woofers at 100Hz and would be much happier if I was able to cross them lower.  We will see how everything integrates into the room and if I do need the extra channel for mid-bass.  I have allowed for it in the design so far, but just have not actually designed such a channel.

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