• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Warwick Hellborg 215?

#22
will33 said:
There are a few different designs called "bandpass". 4th order, 6th order, etc. The basic concept is, middle and upper frequencies don't go around corners well like lower frequencies can. So, by firing the driver downward, or at an angle, or into a chamber inside the box, forcing the sound to travel around corners before it comes out towards the listener, you can use the box to filter out the middle and upper stuff, sort of lowpassing the speaker without a crossover.

There's more to it than that, but it's the basic idea. In a cab like that, they would be using the bandpass to put bottom under the coax that's facing forward.



4thorder.gif




quasisixbandpass_.gif




33738d1322660936-trying-do-budget-home-stereo-sub-setup-icons.jpg




6thordbp_series.GIF
Click to expand...


Way cool - thank you very much Will. :)
 
#23
Are the 4 big holes in the bottom half of the cabinet (bandpass) still considers ports, vents, sound holes, or what? Also, I wonder if the cab is top heavy?

EDIT: Ok, I guess they are still called ports. I don‘t have a full grip on how to tune it on it yet but the whole tuned bnadpass concept is a trip.

Also I don’t understand how there is enough room for two 15s (downward and forward) drivers in separate chambers (airspace) inside the top half of this cab yet?
 
#25
I don't think the woofers share airspace in the top box. Warwicks statement implies that this isn't the case.

In addition to my previous post I'd like to add that I believe the bottom two ports are for the resonance chamber that the bottom driver fires into, and the two ports above that are for the actual enclosure that the bottom driver sits in (Warwicks statement about both enclosures being ported).

Just guessing, but I really think Warwicks statements point in that direction.
 
#27
I'm actually guessing there are two more ports in the top half of the cab that we cant see through the front cloth as they have no chrome trimming.

The reason I think so is that Warwick claims the Club Cab is basically the top half of the Big Cab. Look at the dimensions of the Club Cab.
 
#28
Ok, that makes sense. The “Big Cab” is basically the “Club Cab” with a bass bandpass/driver added. Ok, this is starting to make more since, I need to soak all this in now. The Big Cab concept is a 3way design without a crossover (hmm, or is there a crossover too?) - with the 15” coaxial driver providing the highs and mid’s and the 15” bandpass driver providing the bass. Thank you very much for your help.

I guess my next question is - are the highs controllable - like, a tweeter on other bass cabs can be turned on/off or sometimes up/down?

EDIT: and is the cab crossover less, or is there a built-in crossover?
 
#29
Looking for more info I stumbled across this pic on the web:

[Invalid or Expired Link Removed]

[Invalid or Expired Link Removed]

So there aren't any extra ports in the top half of the cab which means my theory is probably wrong.

Back to square one :hmm:
 
#30
Hmm, yeah, and I just saw that the Club Cab has the big round chrome ports on it as well - so that rules out part of my theory - unless maybe there are ports on the rear top of the Big Cab that we aren’t seeing (but that would make it much different than the Club too)? :hmm:

Otherwise we may be back to what I originally thought and what Mr. Foxen said “At this point pretty sure they share the airspace in the top box, they are on the front and bottom faces.”? :hmm:
 
#31
Ok I’ve been looking at this some more and with the 4th order “compound or band-pass” design the driver is in a sealed box, firing into another ported box - and Warwick says both drivers in the Big Cab are vented - so the downward 15” Celestion bass driver could be a “Quasi-Sixth Order Series -Tuned Bandpass” design that Will pointed out - if the “Quasi-Sixth Order Series -Tuned Bandpass” design is considered vented (it’s looks ported to me) - yes, no?

But, I still don’t see any front ports on the forward custom 15” Celestion coaxial driver - so the top half of the Big Cab isn’t like the Club Cab. I’m still confused and don’t understand how the Big Cab works?
 
#32
Highpassed...even fairly low...the coax can do what it needs to do in a sealed enclosure. The bottom bandpass half is likely 2 ports in the chamber in front of the driver and 2 ports in the chamber behind it with the driver facing either straight up or straight down...inside, where you can't see it.
 
#33
will33 said:
Highpassed...even fairly low...the coax can do what it needs to do in a sealed enclosure.
Click to expand...

Hi guys, thanks for the question on the Hellborg cabinet. The Big Cab is a hybrid construction where the bottom part works as a bandpass, and the top part as direct radiating bass reflex cabinet.
Click to expand...

This much I now understand (thanks guys).

The bottom 15" is mounted on a baffle directed downwards. Both enclosures are vented. <snip>
Click to expand...

Here we learn the driver is "facing downward" and that "both enclosures are vented" -which also seems to indicate the drivers don&#8217;t share airspace?

Anyway, so the top forward coax can&#8217;t be in a sealed cab can it? It sure looks like it could be.

The bottom bandpass half is likely 2 ports in the chamber in front of the driver and 2 ports in the chamber behind it with the driver facing either straight up or straight down...inside, where you can't see it.
Click to expand...

I&#8217;m having difficulty picturing this in my mind - you wouldn&#8217;t have some visual aid (please)? And thank you very much Will.
 
#38
WarwickOfficial said:
Yes, they are sharing "airspace" in the upper cabinet and the bottom driver is out of phase with the upper driver. Hope that helps! Thanks!
Click to expand...

That makes it an isobaric ported cab. With a really big isobaric chamber.

Edit: unless there is confusion with directions they are facing and phase/polarity.
 
#39
May be some sort of hybrid?? It seems it should be adding lowend extension, but the overall spl wouldn't be more than the coax can run on it's own. Be curious as to the drivers used. IIRC, you could run into problems with the HF on long excursion as you'd basically be changing it's quasi "horn path" from long to short to long again on every stroke.

Maybe the struck a balance there, or some other internal driver geometry helping remedy it.
 
#40
WarwickOfficial said:
Yes, they are sharing "airspace" in the upper cabinet and the bottom driver is out of phase with the upper driver. Hope that helps! Thanks!
Click to expand...

Thank you very much. Yes that helps. :)

Mr. Foxen, the bottom bandpass driver is for sure facing downward - it&#8217;s confirmed by Warwick in this thread as well as on Warwick&#8217;s Big Cab demo video with Andy on the Warwick webpage.

Will, the drivers are &#8220;1 x custom designed Celestion 15" coaxial speaker and 1 x 15"
Celestion bass speaker&#8221; - see post 3&4 on page one of this thread (no specs).

Well, now we are getting somewhere, studying this design is much more interesting than most of the simpler designs normally discussed on this TB forum/board and I&#8217;m learning a tons - thank you everyone very much.

EDIT: now I need to read up on &#8220;Isobaric Ported Cab&#8221;, and etc - thank you.
 

Latest posts

Top Bottom
Back