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Just for James...the Q4

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URL: https://forum.speakerplans.com/forum_posts.asp?TID=7878
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Topic: Just for James...the Q4
Posted By: Phil B
Subject: Just for James...the Q4
Date Posted: 21 December 2006 at 11:13am
Well I promised James that I`d let him know about the new NCA 4 x 12 sub...Well the first prototypes are here and just been fired up in anger! The box is long , thin but very narrow ( not much wider than a 12") and designed to be floor stacked in 3`s or more.





The basic layout is the four reversed drivers in a chamber,firing through a slot into a short "w" horn.It`s wired up as a 2ohm box at the mo` that`s to allow the Xta amp that`s gonna power them to use 2x 4 ohm channels. So it`s ideal to stick an FFA on ! 2 ohms into 4 x 600w 12"s!
One on it`s own doesn`t go much below 45hz +/- 3db as it works much like a bandpass ( sounded nice and punchy but the room here is so small can`t tell how far that goes!)but over 3 a side is when the fun starts. The difference as we wound up from 2 to 3 a side was quite noticable but what it does with 4 a side is rude!


I`ll get the spec and charts off of Reay some time soon but let`s just say the plot for four in a corner is bloody frightening!



.p.

edit...been trying to just add links to the fotos to save room but it just don`t wanna make links ..goes back to original page!! Can`t be bothered right now...still recovering from sub-bass overload!



-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/



Replies:
Posted By: ceharden
Date Posted: 21 December 2006 at 11:18am
Trying to work out how the drivers are actually arranged inside the cab.  Certainly a novel design.  Will definitely need to visit and have a listen at some point!


Posted By: james folkes
Date Posted: 21 December 2006 at 11:23am
yaaaaayyy!!!!!

i've got a huge smile on my face now, thankyou very much phil... damnit, when am i next getting down your way... you're making me wonder just what wicked ones will do when stacked. rich continually reminds me that it would be uber nails.

did you end going oem for the driver? i know raey was looking at lots but struggling to find something that satisfied, oh, and they are neo yes? what does the q4 weigh in at?

james.

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mardy hippy.


Posted By: Phil B
Date Posted: 21 December 2006 at 11:26am
Nah they are off the shelf 18sound drivers ....not gonna say much more. He was investigating a Beyma which he reckons should squeeze a few more db lower down ( like it needs it FFS!). I just sooooo wanna take `em to a bigger room ( looks like we might have to drag some kit out sat night!)

.p.

-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: james folkes
Date Posted: 21 December 2006 at 11:34am
will they play high enough to meet the rgw112? and if the answer is yes, have you got dibs on the prototypes yet?! dekked goes totally green, and i'm not talking about envy!

james.

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mardy hippy.


Posted By: Strange Daze
Date Posted: 21 December 2006 at 11:40am
i like em.
Would sit well under some HDs on their side :)
.....
you taking orders?? <laughs>


Posted By: ceharden
Date Posted: 21 December 2006 at 12:07pm
How long do you reckon the horn path is? 1.5m? Longer?


Posted By: Gramps
Date Posted: 21 December 2006 at 12:51pm
Hhhhmmmm... Looks very interesting... Guessing it must be a variation on the "horn assisted bandpass" kinda theme inside, with the drivers sat in pairs in two little side enclosures, facing each other in one central chamber which is vented into the throat of the horn, the path of which is split into two and swings round to the front of the cab...???? Just a hunch....

Bet it sounds helluva punchy as well as going nice and low like you say when you've got some coupling going on.

As long as Giles doesn't get hold of some before the Clash in Feb I don't mind!


Posted By: DJ Coupé
Date Posted: 21 December 2006 at 1:40pm
Nice . wonder how one of my jbl 2206 drivers would perform in one of those cabs. There 600w and 45hz lowest. dunno how the TS parameters compare to what you are using though?


Posted By: Phil B
Date Posted: 21 December 2006 at 8:23pm
Originally posted by Gramps Gramps wrote:

Hhhhmmmm... Looks very interesting... Guessing it must be a variation on the "horn assisted bandpass" kinda theme inside, with the drivers sat in pairs in two little side enclosures, facing each other in one central chamber which is vented into the throat of the horn, the path of which is split into two and swings round to the front of the cab...???? Just a hunch....Bet it sounds helluva punchy as well as going nice and low like you say when you've got some coupling going on. As long as Giles doesn't get hold of some before the Clash in Feb I don't mind!


Pretty much spot on....

I think the concept is great as two boxes per side will work great under a small full range ( Assym) and the full 4 box a side set-up is so much more long-throw than a standard 2x18 box? And has the abilty to small truck pack AND are light! Have`nt weighe one yet but they are def` around the 2 x15" mark.

I will let you all know how it works out, but on my semi-trained sub ear they sounded bloody awesome! Loads of fast attck bass but going really LOW! I still have the image of all the tools on the workshop bench jumping up and down ( nothings made that happen ever before!)

.p.

-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: Phil B
Date Posted: 21 December 2006 at 8:27pm
Originally posted by james folkes james folkes wrote:

will they play high enough to meet the rgw112? and if the answer is yes, have you got dibs on the prototypes yet?! dekked goes totally green, and i'm not talking about envy!

james.


At first listens it played up to 125hz no probs ...the rgw goes down to 80hz.

Dunno about dibs on the prototypes ...lets just say some exhaustive testing is about to begin! If they can stand a month with us then I reckon they`re safe for you lot!

.p.

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Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: jbl_man
Date Posted: 22 December 2006 at 4:17am
Those 4x12s look very nice Phil...the exterior dimensions remind me of the S1 bin...sort of "square" on end profile....also loads of attack and fast transient response from four 12" drivers.the cabinets look beautifully made..expensive? must be over 2 grand a box when loaded i reckon?
Ian.


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Be seeing you.


Posted By: Phil B
Date Posted: 22 December 2006 at 9:57am
Ok as promised here`s the plots

(edit ..all plots at 600w a driver)

indoors 1/4 space. plots for 1 to 4 boxes



and this is the plot for 1,2,3,4,6,8,12 outdoors



Seems to go higher tha I thought! Did notice that it handles the upper bass very nicely. Nice hump at 35hz as well and obviously the more together = more fun!
As to price I think they`re going to be quite "cheap" as they use off the shelf drivers and aren`t too complicated to make? Obviously the self powered versions are gonna have the cost of an Xta amp. I`ll let you know when a price is set?

.p.

-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: Phil B
Date Posted: 22 December 2006 at 11:22am
Originally posted by DJ Coupé DJ Coupé wrote:

Nice . wonder how one of my jbl 2206 drivers would perform in one of those cabs. There 600w and 45hz lowest. dunno how the TS parameters compare to what you are using though?


You`ll prob find they run out of excursion at 200 watts!

.p.

-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: turbodeas
Date Posted: 22 December 2006 at 5:07pm
those plots look yummy!

I used the traditional NCA 2*18 V bin over the summer, and that had some thump.

how would these compare to the V bin in terms of response and size/weight?

blue skies,

chris.

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http://www.hotmastering.com" rel="nofollow - http://www.hotmastering.com


Posted By: MarjanM
Date Posted: 23 December 2006 at 4:29am
Which 18 driver will that be then?

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Marjan Milosevic
MM-Acoustics
www.mm-acoustics.com
https://www.facebook.com/pages/MM-Acoustics/608901282527713


Posted By: james folkes
Date Posted: 23 December 2006 at 5:59am
Originally posted by MarjanM MarjanM wrote:

Which 18 driver will that be then?

that'll be the fane 18xb...

james.

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mardy hippy.


Posted By: MarjanM
Date Posted: 23 December 2006 at 6:05am
I meant to ask what 18Sound driver. Sorry for my mistake.

-------------
Marjan Milosevic
MM-Acoustics
www.mm-acoustics.com
https://www.facebook.com/pages/MM-Acoustics/608901282527713


Posted By: Phil B
Date Posted: 23 December 2006 at 10:24am
Originally posted by james folkes james folkes wrote:


that'll be the fane 18xb...

james.


The new vsb uses these..



http://www.eighteensound.com/index.aspx?mainMenu=view_product&pid=230 - link


can`t really say about the 12" driver ...soz

.p.

-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: james folkes
Date Posted: 24 December 2006 at 9:31am
you lot have become shameless 18sound whores, you know that?

i hope this means you'll be able to cut some amazing deals as distributors to pass on to us humble end users then... around about this time next year (we hope) we ought to be in a position to upgrade all the 15"s and 10"s in the rig for 18sound neos; smps touring class amps first, but that'll be the next big overhaul.

james.

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mardy hippy.


Posted By: Phil B
Date Posted: 24 December 2006 at 2:48pm
Originally posted by james folkes james folkes wrote:

you lot have become shameless 18sound whores, you know that?

i hope this means you'll be able to cut some amazing deals as distributors to pass on to us humble end users then...
james.


The reason is simple.....they work really well and are really reliable...

As for deals you`ll have to butter Steve up at NCA ...I`m only a user like you!

.p.

-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: JD01
Date Posted: 26 December 2006 at 2:25pm
Is it a conventional or a ND driver (the 12" I mean)? I ask because the NDs are sensitive to heat, so putting their magnets in a small sealed back chamber could be bad. It does not need to be a breakdown at once, but they could loose magnetic flux over time...


Posted By: Phil B
Date Posted: 26 December 2006 at 2:34pm
It`s a normal ferrite driver, and the drivers are reversed so all the baskets are in the horn mouth. The way they`re placed means that they have large side vents which allow the heat to be passed out of their sides rather than out of the pole piece vent.

.p.

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Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: JD01
Date Posted: 26 December 2006 at 2:46pm
That is a good thing. Did you compenaste for the discontinuity in flare rate at the horn throat caused by the magnet?
 
So if you want go down to 35Hz I guess it is a pretty high XMax driver with relatively heavy cone, right? Does it sound really good at 200Hz? I mean, measured frequency response doesn't tell to much about sound quality....


Posted By: mrfuzz
Date Posted: 26 December 2006 at 2:49pm
ah ha! the power density, breakfast in bass form, am I right in guessing that its a bit like a banpass cab with the horn on the port?

ta, will


Posted By: JD01
Date Posted: 26 December 2006 at 2:52pm
Only because the driver is mounted backwards doesn't mean that the horn is coupled to a resonator (port).


Posted By: Phil B
Date Posted: 26 December 2006 at 4:48pm
Originally posted by JD01 JD01 wrote:

That is a good thing. Did you compenaste for the discontinuity in flare rate at the horn throat caused by the magnet?

So if you want go down to 35Hz I guess it is a pretty high XMax driver with relatively heavy cone, right? Does it sound really good at 200Hz? I mean, measured frequency response doesn't tell to much about sound quality....


Haven`t had a chance to use `em properly yet! So no I don`t know what they sound like at 200hz. The quick test we did showed they sounded good up to 125hz ( just what we happened to use as the hp setting). Hopefully over the next month we`ll get a good chance to measure the boxes properly!
As Mrfuzz said the chamber is seperate from the horn flare and yes the extra basket space was accounted for.

.p.


edit I said horn mouth in my last post ...I meant the drivers are reversed into the chamber NOT the horn mouth!
Too much xmas dinner confusing my brain still!


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Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: ceharden
Date Posted: 26 December 2006 at 7:03pm
Keep asking the right questions guys, we'll have enough to design our own very soon!  Mwa ha ha ha!

From what I'm reading, it's nothing particulaly novel but the hard part is to get a good design it into a nice useable box which you can lift,pack in a truck and will survive local crews and idiot engineers!

I like the idea anyway, especially as it confirms I've got some things right on my own designs!  Keep posting the test results Phil!



Posted By: JD01
Date Posted: 26 December 2006 at 7:25pm

It's doing what now? The magnet in the back chamber or into the horn throat direction?




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