Old fashioned 12inch 3 way

What people are working on at the moment
User avatar
Dr Bunsen Honeydew
Old Hand
Posts: 1358
Joined: Mon Sep 21, 2009 10:50 am
Location: Muppet Labs

#31 Re: Old fashioned 12inch 3 way

Post by Dr Bunsen Honeydew »

ed wrote: Tue Jun 13, 2017 11:10 am oooh, I'm still trying to get my head around this, it looks like a trixy concept

If I'm reading your synopsis correctly then the 12" driver must have exactly the same compliance as the smaller driver, otherwise in my head I can see them interfering with each other. Mainly the 12" interfering with the smaller one.

If this is the case then it looks necessary to have the Qt figure for both drivers, but again in my naive head I didn't think this figure was available to Ed Vilchur when he was doing his work. I didn't think it was an exact science until Thiele and Small did their thing. Does this mean that Ed was doing all this by trial and error?

further, to approximate the volume for the enclosure in todays terms how would you sum the Qt of the 2 drivers with respect to the total compliance?

apologies if this is venturing into the objective realms Richard.

edit: just had a further thought...this could reap big benefits if the 12" was a field coil driver, then you could twiddle to get a good match. This would of course necessitate the use of measurements as ones ears would not produce a good result for somebody elses ears, i.e level the playing field(no pun)
In my case the doping levels the playing field, and that is done by ear. In Ed Villchur's case only very early AR1 had a cone mid/hf driver, he just did it and it worked. He then designed the first dome tweeters which were of course sealed back and then the first domed midrange again sealed back. Roy Allison took this design process on further after leaving AR. Villchur was going deaf, which is little known, and one of the main reason he sold the company to work on hearing aids.

Once again I see brains blocked by theory, equations and test gear, completely bypassing brains, instinct, emotion (music) and ears. My beef with Moose.
User avatar
Dr Bunsen Honeydew
Old Hand
Posts: 1358
Joined: Mon Sep 21, 2009 10:50 am
Location: Muppet Labs

#32 Re: Old fashioned 12inch 3 way

Post by Dr Bunsen Honeydew »

shane wrote: Tue Jun 13, 2017 11:51 am If I put Also Spracht Zarathustra on at a decent level, why won't the bass unit blow the midrange cone out of it's basket? An extreme case, I grant you, but I'm just trying to get my head around the concept.
Why should it, they are both pushing in the same direction at the same time. It is like saying why doesn't the 12 inch blow its own cone out of its basket.
User avatar
Nick
Site Admin
Posts: 15706
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#33 Re: Old fashioned 12inch 3 way

Post by Nick »

Why should it, they are both pushing in the same direction at the same time.
But if they are doing that then they are seeing the same signal. Are you not using some form of high pass filter for the mid range?
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Dr Bunsen Honeydew
Old Hand
Posts: 1358
Joined: Mon Sep 21, 2009 10:50 am
Location: Muppet Labs

#34 Re: Old fashioned 12inch 3 way

Post by Dr Bunsen Honeydew »

Nick wrote: Tue Jun 13, 2017 1:14 pm
Why should it, they are both pushing in the same direction at the same time.
But if they are doing that then they are seeing the same signal. Are you not using some form of high pass filter for the mid range?
I don't intend to. I have done this before with two drivers. I want to series wire them first, that has other benefits as well, problem it may make the result just too inefficient. BUT it is a project, I know what I want to try first.

As the hippy said "its all in the dope" :mrgreen:

BTW these drivers are not designed as mid range drivers, they have big motors. I use them as the bass/mid in Cube 3.
Daniel Quinn
Old Hand
Posts: 859
Joined: Thu Jan 05, 2017 9:19 am

#35 Re: Old fashioned 12inch 3 way

Post by Daniel Quinn »

Prior to moving to my much smaller listening room , my first doc mod project in 2010 was a large 3 way . 2 audax 8 inch drivers, 1 tweeter , I wired them as advised by the doc and placed a cap and resistor on the tweeter and sealed the box . { this was my first post on the old h/s and his first bit of advise } At the time it was a revelation as I had been struggling to cobble together a crossover I liked for 9 months .
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#36 Re: Old fashioned 12inch 3 way

Post by shane »

Dr Bunsen Honeydew wrote: Tue Jun 13, 2017 12:30 pm
shane wrote: Tue Jun 13, 2017 11:51 am If I put Also Spracht Zarathustra on at a decent level, why won't the bass unit blow the midrange cone out of it's basket? An extreme case, I grant you, but I'm just trying to get my head around the concept.
Why should it, they are both pushing in the same direction at the same time. It is like saying why doesn't the 12 inch blow its own cone out of its basket.
Hmmm, ok, I can sort of see where you're coming from. Hope I get the chance to see and hear these in action!
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#37 Re: Old fashioned 12inch 3 way

Post by shane »

Daniel Quinn wrote: Tue Jun 13, 2017 1:59 pm Prior to moving to my much smaller listening room , my first doc mod project in 2010 was a large 3 way . 2 audax 8 inch drivers, 1 tweeter , I wired them as advised by the doc and placed a cap and resistor on the tweeter and sealed the box . { this was my first post on the old h/s and his first bit of advise } At the time it was a revelation as I had been struggling to cobble together a crossover I liked for 9 months .
Were the 8" units the same? I can see how that would work. Where I have difficulty is in understanding why the doc's proposal won't have the mid overpowered by the rear output of the bass unit. Looking forward to seeing his progress.
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
Daniel Quinn
Old Hand
Posts: 859
Joined: Thu Jan 05, 2017 9:19 am

#38 Re: Old fashioned 12inch 3 way

Post by Daniel Quinn »

shane wrote: Tue Jun 13, 2017 2:14 pm
Hmmm, ok, I can sort of see where you're coming from. Hope I get the chance to see and hear these in action!
you could just buy yourself a pair of Cubix Pro . :mrgreen:
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#39 Re: Old fashioned 12inch 3 way

Post by shane »

Can't do that. This is s DIY forum!
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
Daniel Quinn
Old Hand
Posts: 859
Joined: Thu Jan 05, 2017 9:19 am

#40 Re: Old fashioned 12inch 3 way

Post by Daniel Quinn »

Fair point , I apologise for my ridiculous suggestion .
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#41 Re: Old fashioned 12inch 3 way

Post by shane »

What would interest me would be trying Doc mods on a pair of HB3s. Sadly likely to be vetoed by domestic management...
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
Daniel Quinn
Old Hand
Posts: 859
Joined: Thu Jan 05, 2017 9:19 am

#42 Re: Old fashioned 12inch 3 way

Post by Daniel Quinn »

Why , aesthetically there is very little difference ?
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#43 Re: Old fashioned 12inch 3 way

Post by shane »

True, but for the above reason my old HB3s gave way to a pair of Mission 782s 15 years ago. I doubt that the return journey would be approved.
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
User avatar
Dr Bunsen Honeydew
Old Hand
Posts: 1358
Joined: Mon Sep 21, 2009 10:50 am
Location: Muppet Labs

#44 Re: Old fashioned 12inch 3 way

Post by Dr Bunsen Honeydew »

Cubix pro are different they are two or three 8 inch drivers each in their own acoustic suspension boxes configured in an upward tower coupled in *so called* isobaric mode with built in amps for each module :shock: lots of dosh, only built to order and bespoke.


http://www.hifisubjectivist.org/viewtop ... =cubix+pro


http://www.hifisubjectivist.org/viewtop ... =cubix+pro
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#45 Re: Old fashioned 12inch 3 way

Post by shane »

Typical. As soon as the idea comes into my head, these appear on eBay.

I must resist
I must resist
I must resist

https://www.ebay.co.uk/itm/162550819370
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
Post Reply