Mar-Kel70 in Sweden

frugal-phile™
Joined 2001
Paid Member
http://www.diyaudio.com/forums/full-range/158162-new-lotus-project.html
http://www.diyaudio.com/forums/full-range/158162-new-lotus-project.html

also some comments in CHR applications thread.

Part of the British Auto Series

Lotus-3D.gif
Lotus-3D2.gif


dave
 
Well, it looks like it might be a sportscar - and instead of the stack of wood at the bottom, perhaps one 45° panel forming a Helmholz trap to kill the standing wave (lengthwards)?
Probably not necessary, but someone who has time on his hands while finding the money might torture his compooter.
Niklas, we are looking towards where the fearless Vikings dwell.
 
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1.65m between the speakers.
Around 2.30m between me and speakers.


hmm, I could be all wet, but see my earlier comments re integration of the combined output of the dual mouth/vents and direct from drivers at such a close listening position

even a single driver version, particularly if supported by powered woofer, would likely have no problem with "sane" SPLs and bass energy, but you could be sitting too close to get seamless integration of essentially 3 sources, and imaging could suffer.
 
Well, could possibly move the speakers around 10cm further away from eachother and sit maybe 20-30cm further back if needed.

Well, is a Lotus good for my room (both 1 and 2 speaker version)?

And is it possible to have 1 driver in the front and one on the back?


Niklas - we should let the enclosure's designer ( Scott) answer those, but I can't help but suspect that

- 30cm (approx 12") might not make enough difference

(edit: i.e. that's a total separation of 5.7 ft,, which is probably fine, but at a listening distance of 8.5ft I think you could have some problems of integration . I don't own a pair of any of the dual mouth systems, but on the several occasions I've heard them, they've been in much larger spaces with listening distances of at least 3-4meters )

- dual drivers would be fine on either the front or side of the chamber, but not so much on the rear

There are numerous bipole designs that would work:

Metronome

I'm not sure if there's a link yet to designs for bipole version with Mark Audio drivers?

Jim Griffin's offset MLTL

http://homepage.mac.com/planet10/CSS/EL70/Griffin-offset-bipole-mltl-100909.pdf

P10 microtower (page 4)

http://homepage.mac.com/tlinespeakers/FAL/downloads/microTower-maps-150909.pdf

Scott's "Wessex"

http://homepage.mac.com/tlinespeakers/Woden/downloads/Wessex-MLTL-0v92-151209.pdf

etc), but you'll need at least 50cm (preferably more) with a rear firing driver. I keep coming back to the suggestion of the Castle version (i.e. upward firing second driver) of the microtower design for this type of situation.
 
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I wont do this until the summer. Got no money right now. Just spent around 230$ on a new gfx card and will spend another 300$ as soon as i can on an Intel X25 80gb SSD.
But, will do some work in a few weeks (when the snow is gone) and earn some money that way too.

But, i am pretty sure it will be Lotus (wasen't it Scott who told me about them?) with 1 or 2 drivers...
 
I wont do this until the summer. Got no money right now. Just spent around 230$ on a new gfx card and will spend another 300$ as soon as i can on an Intel X25 80gb SSD.
But, will do some work in a few weeks (when the snow is gone) and earn some money that way too.

But, i am pretty sure it will be Lotus (wasen't it Scott who told me about them?) with 1 or 2 drivers...


Several months allows plenty of time for numerous spins on the design carousel, by which time there may even be greater choice of drivers and accompanying designs at the DIY smorgasbord
 
Yes, that's right but i ain't got money at the moment and my working space is very limited. I will do the building outdoors, wouldn't even get a 4x8ft board into the workshop!

Smörgåsbord, hehe ;)

Edit: Btw, what's the difference between Coniston and Lotus? They look the same to me.
 
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Yes, that's right but i ain't got money at the moment and my working space is very limited. I will do the building outdoors, wouldn't even get a 4x8ft board into the workshop!

Smörgåsbord, hehe ;)

Edit: Btw, what's the difference between Coniston and Lotus? They look the same to me.


Similar topology, but tuned for the different T/S parameters of the EL70 (paper) and CHR70 (metal cone)

Coniston is taller and wider, with slightly larger driver chamber, and substantially different dimensions to throat and mouth of vents.

Of course, either driver would "work" in either box, but not optimally.

and if my suspicions as to minimal listening distance are correct, the taller enclosure would exacerbate the integration problem in a smallish room
 
Lotus should be OK; it's shorter than the others. Conniston would be pushing it though.

Bipoles (forward & rear-firing) would be a bad idea; you'd have to pull the boxes out from the boundaries. Ditto with semi-omni (could've sworn I've already said this...) with the side-firing unit. If you want twin drivers per channel, in that room, get them both on the front baffle, as close together as possible.

Btw, what's the difference between Coniston and Lotus? They look the same to me.

Take a look at the dimensions. ;)