MTG-06-OWS (On Wall Surrounds) Aura NS6 + DNA-150/EOS-6

Re: MTG-06a-OWS

Here is the Indoor on wall vs outdoor free space driver measurements:


Looks like crossover region and above is mostly uneffected by placement on wall (just a dB here or there). The lower range does not see the boost from the wall placement in the free space however the unavoidable peaks and dips from wall placement are of course gone.

 

Re: MTG-06a-OWS

I think I will go with the third order crossover it is only an extra $5 per speaker over the 2nd order and goes down to $4 when you order two or more.

For those interested here is the parts list from PE:

DNA-150, EOS-6 and bolt-on to screw adaptor would need to be purchased through DIY sound group. Total for the drivers/XO comes to $62.62 per speaker ($61.70 if you order parts for two or more).

Here is the schematic also:

 

Re: MTG-06a-OWS

Need some copper to finish these, I have a stockpile of caps and resistors but ran dry on most coils.
I am also waiting to figure out what parts are needed on a design or two more before I put in an order. Some stuff from Erich just showed up so it should not be long.

 

Re: MTG-06a-OWS

I am going into a little more detail of my finishing process on these. My first step is to fill any seems or cracks where the panels meet and also any other deformities. I like to use regular wood filler because I can just wash it off my hands with water if they get full of it.


Next step is to sand them smooth.


I don’t think the mess up I made while routing the recess for the waveguide will be visible at all after the primer is on.


I almost forgot to do something before I brought them outside to spray on the primer. I had the terminal cup just surface mounted on the top. After a while I decided I did not like the look of that. So I borrowed a tip from PassingInterest.


You can use a top bearing flush trim bit to make a cutout larger or in my case create a recess for the terminal cup.




Piece of cake.

 

Re: MTG-06a-OWS

My Paint booth setup and enclosures ready for primer.


I use Zinsser FastPrime2 which is a water based primer, I think it works well on mdf. What I really like is that it dries fast, does not smell, and is cheap. I just picked up another gallon from Menards for $12. The only downside when spraying it is that it will tend to clog the nozzle after a little while. I thin it quite a bit 1-1.5 oz of water per 8 oz of primer (which is enough to cover these in a pretty thick coat) and that helps with the clogging some.


I found that you should thin before running it through the filter; otherwise it takes forever to go through. Once filtered I add it to the gun, adjust and start spraying.


Here I have the first side done, it really goes fast.


First one done ready to start on second.



After they were both done I let them dry for about 3 hours then sanded and applied a second coat.

 

Re: MTG-06a-OWS

I finished painting these the other day. I only got one coat on them though beacuse I broke the spray gun. Dropped it while cleaning it and paint intake tube broke off.



Still need the crossover parts, I am going to place my order from PE at the special time on monday to get the free 1 day shipping.
So the crossovers should be built and I will be listening to them by mid next week.

 

Re: MTG-06a-OWS

Spayer was this one: http://www.menards.com/main/tools-hardware/power-tools/air-compressors-pneumatic-tools-accessories/basic-spray-gun/p-1655227-c-9076.htm
It should be by the air tools, not in paint. Also the gallon of primer was $12, spray gun is $22.

External dimensions are 13” high, 8” wide ~7.75 at top and ~4.25” at bottom which is about a 15 degree slope (15.068). 3/4” front baffle, rest was 1/2”.

 

Re: MTG-06a-OWS

I built the crossovers for these yesterday and gave them a listen. They sounded pretty bright.

Today I got around to measuring them and guess what, the CD is running about 5dB hotter then it showed in PCD. I think it was a bad alligator clip test lead that I used when first measuring the drivers on these. I found that when testing with the WT3 and it showed a impedance that was 1.5-2ohms higher then it should have been. I have nice new ones I made with 16 awg wire soldered onto the clips which I now use. A quick change to a from a 4 ohm to a 3 ohm resistor in parallel on the tweeter brought it down.

I think these sound very similar to the MTG-08's going by memory. I'll need to do a side by side comparison but right noe I can't really pick out anything that stands out between the two as far as SQ is concerned. Same neutral clear articulate sound. These do rolloff earlier then the MTG-08's (about 90hz) and they cannot play as loud but are still able to hold together real well as the volume is turned up. I measured the sensitivity at just about 89dB/1m 2.83v.

Now I was listening to them proped up in a bookshelf orientaion not on wall like they are designed to be mounted. I think a bookshelf design with same baffle size could use the same crossover. I think these will make excellent surround speakers for those not needing reference SPL levels.

I was planning on doing a full set of outdoor measuremnts showing off axis response but it started rainning just as I was bringing the gear outside.
This one was done indoors stand mounted (not on wall):

 

Re: MTG-06a-OWS

Thanks,
They are happiest below 50-60 watts, but I am sure they would be fine (as in no driver damage) up to 100 watts with a highpass filter at 80hz.

 

The waveguide does affect the sound of the driver used in it. So even if the DNA-350/360 was to be used in the EOS-8 it might not exactly match the sound of one in the SEOS-12. I really doubt the timber differences between of the 205 or 150 would be all that noticeable when setup as surrounds with 350/360 mains. The differences are quite subtle and will be masked by the different placement of those speakers within the room.


I would suggest Tux’s Fusion-10 Max, he also an 8” SEOS-12 design using the Eminence alpha-8 and 150, but if your thinking something smaller or narrower yet still more powerful then this I would suggest going with one of the other 8” designs. I know Tux has another one he has been working on using the Alpha 8 and DNA-150 but with the DW-854B waveguide but I don’t think he has a thread on it yet. Then there is Jeff’s fusion-8 which uses the Beta-8 and 205 with the EOS-8 and then my 8” designs, the MTG-08, and Minion designs. I also did one using the Celestion woofer from the MTG-08 and the DNA-150 in the EOS-8 waveguide. I don’t have a thread for that one but it will become the Karma-8 kit.


As for the bipole using waveguides, I guess that could work, Klipsch makes a few like that. Though I have no experience with bipole design.

 

Yeah you should be able to convert an 8" design to a wall mount enclosure without any crossover changes. Both the MTG-08 and Minion have a little bit of baffle step comp built into the crossover but on wall placement should be too bad, in wall placement is another story.

A bipole design would be interesting, your looking at almost double the cost though. I am also starting to think that if you sat on axis, between the baffles the pattern control of the waveguides would roll the high frequencies off at that angle and they would sound quite dull.

 

You may be able to find some on Ebay but they will usually be priced a bit higher then $9 a piece. No direct substitute for the Aura's I do have some new 6" designs in the works that could be made into the same form factor as these though one is slightly lower sensitivity but has better bass extension and will be capable of more output down low. The other will cost much more but uses a nicer driver has similar sensitivity and is more capable. Don't expect them too soon I don't even have the baffles done yet.