A Big'un - the Audio Nirvana Super 15

[DeonC]

Not a labrinth, as the verticle strips are made up of damping material, not solid wood. So it is more like a silencer. The strips are made from something like carpet felt. At least that is my understanding of it.

Enjoy,
Deon

 

[planet10]

Would need to be a lot longer to be a labyrinth. It would be called a heavily damped U-Frame in today's nomenclature.

Was patented 4 year sbefore the labyrinth.

dave

 

[planet10]

Not a labrinth, as the verticle strips are made up of damping material, not solid wood. So it is more like a silencer. The strips are made from something like carpet felt. At least that is my understanding of it.

Exactly. Today you'd use Ultratouch (as Gary Pimm does), or fiberglass insulation.

dave

 

[Melon Head]

although its motor is small/weak, you could put it into a Karlson enclosure from K15 to K18 size. Coat the front chamber well with varnish, etc. and enjoy.

What are the optimum parameters for the Karlson?

 

[Bare]

the floors in my house use wooden i-beams, very stiff (much better than my last house that used regular joists) and lightweight (photo) and much more practical than using thicker and thicker floor boards.

Do know that Tannoy DMT II's Twin 15's, use a Medium sized BR 'Box' comprised of a double layer of 1" MDF stuck together with some rubbery /absorbant adhesive. Box within a box setup. Also have crossed internal Driver bracings.
Seriously heavy but it clearly works.
My listening experiences with these... genuinely Impressed.
The Bass is simply astounding. deep, clear and sharp. (Ferrite Motors= sharp bass) It's more than palpable.
Marvelous midrange and exquisite highs. Very little about those to criticize.. albeit only IF the upstream sources are capable .

Find and emulate their constructions? One could do a lot worse for a startpoint. Google is our friend.

Ohh by the way: Truss joists, those things in your Photo.. are BAD for turning floors into drum skins.. true.
Even the 1 1/2" concrete topping typicaly poured over, only partially deals with the problem.
Often New isn't always improved .

 

[freddi]

for a Karlson and fullrange, low moving mass, some on-axis rise and qts not much higher than 0.5 are good - but I've had some speakers such as guitar speakers and vintage fullrange with Q around 0.7->1 play well without boom---- if the speaker has a "bright" character as a direct radiator it will tend to balance well in a Karlson.

A Karlson will make good use of a fullrange speaker's power by controlling in band and below band cone excursion - to me that's more important than small signal extension and allows better performance on complex passages than reflex.

 

[Bigun]

Do know that Tannoy DMT II's Twin 15's, use a Medium sized BR 'Box' comprised of a double layer of 1" MDF stuck together with some rubbery /absorbant adhesive. Box within a box setup. Also have crossed internal Driver bracings.
Seriously heavy but it clearly works.
My listening experiences with these... genuinely Impressed.

I like this idea Bare. I am now planning to start the build by constructing the 'inner box' from the 11.5 mm Birch Ply. Then after that, I will add a 2nd box over the top, gluing it on top one sheet at a time, using a viscoelastic glue.

The internet brings up a lot of talk about Green Glue for this purpose. I checked out the MSDS for this material - it's nothing more than Latex glue loaded with chalk (a common practice). So I'll be looking for a much more cost effective option of a generic latex glue from a local store.

 

[Melon Head]

You can make it yourself

 

[Melon Head]

although its motor is small/weak, you could put it into a Karlson enclosure from K15 to K18 size. Coat the front chamber well with varnish, etc. and enjoy.

for a Karlson and fullrange, low moving mass, some on-axis rise and qts not much higher than 0.5 are good - but I've had some speakers such as guitar speakers and vintage fullrange with Q around 0.7->1 play well without boom----

Go back to page 1 and look at the spec sheet.
What part of Qts=0.483 is considered weak

 

[Melon Head]

I like this idea Bare. I am now planning to start the build by constructing the 'inner box' from the 11.5 mm Birch Ply. Then after that, I will add a 2nd box over the top, gluing it on top one sheet at a time, using a viscoelastic glue.

The internet brings up a lot of talk about Green Glue for this purpose. I checked out the MSDS for this material - it's nothing more than Latex glue loaded with chalk (a common practice). So I'll be looking for a much more cost effective option of a generic latex glue from a local store.

I thought you didn't want a heavy box. Hahaha
Go for it.

 

[Bigun]

I thought you didn't want a heavy box. Hahaha
Go for it.

I don't. I guess I gotta Man Up

 

[Bigun]

so I've glued up some scrap pieces of birch ply on the back of the baffle to provide some additional depth and support for the driver to mount into. I'll be dusting off my router shortly.

 

[Bare]

Big Sound = Big Boxes 15's are serious implements
I have Tannoy GRF/Westminsters These things are bigger than my 22 cu ft Refrigerator. BUT when I close my eyes they disappear entirely.
Frankly, dunno about your drivers.
I'd Be seriously considering buying a set of Used Tannoy DMT's... Reasonably priced too...as they are Below the typical Audio Weenie's radar.
Sound? Unequaled .. except by 3 pairs of Martin Logans' finest product, 2! Velodyne subs powred by 4! serious quality Amps..all 125$K worth . Friend's setup.

 

[Bare]

This is what a GRF/Westminster is like.
Seriously unlikely the Nirvana drivers are fit for these, but at least look at what is Time proven.
Rick's Tannoy Autograph Enclosures

 

[blakkshepeaudio]

DIY Green Glue ?

You can make it yourself

I would be very intereted in this. Green Glue gets expensive real quick in the quantities needed to be useful in cabinet construction.

Tell me more........

blakktie

 

[Melon Head]

This is what a GRF/Westminster is like.
Seriously unlikely the Nirvana drivers are fit for these, but at least look at what is Time proven.
Rick's Tannoy Autograph Enclosures

Bloody Hell. He hasn't even finished yet. There is also the possibilty they might be equal or better. I'm not stating that as fact as I usually reserve judgement until I have experiencec something first hanc.

Anyway thanks for that link. I have some more things to try now.

 

[GM]

Go back to page 1 and look at the spec sheet.
What part of Qts=0.483 is considered weak

Over ~0.383 or ~0.403 Qt depending on which math is used = 'weak' motor since cab net Vb required is > Vas.

GM

 

[Melon Head]

Over ~0.383 or ~0.403 Qt depending on which math is used = 'weak' motor since cab net Vb required is > Vas.

GM

No arguement, I agree, but you have taken what I said out of context. It was in the context of what was suitable for a Karlson cabinet, given that anything below .5 is suitable then a value of 0.483 is acceptable not weak
Anyway I don't know enough about the Karlson to comment, but nothing was said about Vb or Vas just the requirement for Qts

 

[GM]

Not the way I read it. Regardless, it doesn't matter what type cab alignment is used and when referring to a driver's effective motor strength it's either some degree of strong or weak. You asked what part made it weak and I gave you the reason.

WRT the Karlson, it can be up to an 8th order BP, so can 'squeeze' the driver enough to alter its specs somewhat and at some point the driver's suspension and/or diaphragm begin audibly distorting from the acoustical pressure, which at this point even a weak motor could appear strong, so ideally one wants a mid-bass horn driver's specs/construction for best overall performance.

I imagine an Altec/GPA 515-8g in a K15 could pound the breath out of you at rated power.

GM

 

[Melon Head]

Yes your response is informative so thanks for that