Warwick Hellborg 215?

[will33]

It may not be all strictly a single design concept. It seems the downfiring driver would just be adding lows/port output and maybe lowering extension via the isobaric concept. As to running them in the same chamber?

Some of this is getting outside the comfort of my hands-on experience. Read up on bandpasses, isobarics, etc. but never sat down and designed and built one all the way through. You can achieve similair things in simpler, cheaper to build boxes using more purpose specific drivers and a crossover. Likely why you don't see them much in commercial designs. Bandpass is still used quite a bit in car subs.

That one seems like you've got a coax in a box with another woofer that's just adding bass to it, the box cancelling woofers mids/highs.

 

[Joe Louvar]

PS: your right Will - Warwick said the Big Cab is a hybrid - and I’m glad this caught you curiosity because I’ll learn from your answers and questions as well. Thanks again for all your help.

 

[WarwickOfficial]

In simple jargon...the design extends the range downwards, in terms frequency.

 

[will33]

I take that to mean it's isobaric with the woofer being downfired helping the box cancel mids/highs and letting the coax play those.

Be interested in what differences, if any, between the internal woofer and the coax's woofer cone.

 

[Mr. Foxen]

If it is isobaric, whats the point of the really big top chamber? Sort of defeats the point of isobaric loading meaning you can use a smaller box.

 

[Joe Louvar]

I’m playing catch-up (reading up) - I have much to learn.

With my limited understanding I’m thinking it’s maybe kind of like an Isobaric design because the drivers are coupled to work together in same airspace, etc, but a Hybrid - because the drivers are side and bottom firing appose to chasing and the drivers aren’t identical, plus the added Bandpass chamber? So maybe like a Isobaric/Bandpass/+ ?

 

[Mr. Foxen]

I’m playing catch-up (reading up) - I have much to learn.

With my limited understanding I’m thinking it’s maybe kind of like an Isobaric design because the drivers are coupled to work together in same airspace, etc, but a Hybrid - because the drivers are side and bottom firing appose to chasing and the drivers aren’t identical, plus the added Bandpass chamber? So maybe like a Isobaric/Bandpass/+ ?

Isobaric needs them working together push me pull you style, so the air pressure stays the same in the chamber between them. Once you have that, the ported chamber is the same as the box behind a normal speaker cab, except instead of the back of the cone, you have the front of the other one. The port output effectively being bandpassed on a normal ported cab since only lows (assuming its tuned low) come out the port (unless they've done it wrong and mids come out too).

 

[Joe Louvar]

Isobaric needs them working together push me pull you style, so the air pressure stays the same in the chamber between them. Once you have that, the ported chamber is the same as the box behind a normal speaker cab, except instead of the back of the cone, you have the front of the other one. The port output effectively being bandpassed on a normal ported cab since only lows (assuming its tuned low) come out the port (unless they've done it wrong and mids come out too).

Thank you, I get it now "so the air pressure stays the same in the chamber between them". I’m still reading - I just learned the drivers in a Isobaric design can also be mounted “cone to magnet” and wired in phase, or “cone to cone” or “magnet to magnet” and wired out of phase but there could be some distortion issues with the latter two. Anyway, I’m going to need to soak in everything else you just said because it’s over my head right now - but, I’m learning a little more everyday.

Thank you very much for your help Mr. Foxen.

 

[Mr. Foxen]

The classic isobaric is the Amepg Isolvent where they are mounted face to face, clamshell style. There is always issues with the two cones because of the time it takes the wave to get from one to the other effectively putting them out of phase at some frequencies.

 

[Joe Louvar]

Perfect, I wish the articles/textbooks etc would explain non-linear behavior or non-symmetrical behavior and etc in easy to understand words like you do - way cool and thanks again.

EDIT: PS - I just read that absorptive materials could be used between drivers to absorb some of the possible distortion components within the chamber.

 

[Joe Louvar]

Ok, I think this about as much as I’m going learn about how the Warwick Hellborg Big Cab (215) works. I learned a lot (also the more I learn the more questions I have too, lol). The Big Cab grabs my curiosity because of the unique loudspeaker design developed by the Celestion R&D team, for Warwick.

Thank you everyone for your help, it’s much appreciated.

 

[Mr. Foxen]

The Big Cab grabs my curiosity because of the unique loudspeaker design developed by the Celestion R&D team, for Warwick.

Starting to suspect its about as unique as when Orange did it with their SP stuff. Guess a coaxial tweeter is a plus. The still being really big, not so much though.

 

[shaft311]

Just to correct something here.. The bottom subwoofer is not a downward-firing driver, but an upward-firing one.

I received my Big Cab last week and upon removing the grille I discovered this (magnet on the bottom, cone on top). I thought there was a mixup when mine was built, but I confirmed with another Big Cab owner and his is upward firing as well.

It doesn't matter much to me as the cab sounds huge, especailly as you move farther away from it, but anyone expecting a downward-facing driver needs to know this info.

 

[vigor&kandor]

I would love to see some more pics of this cab. Preferably with grill off.

 

[shaft311]

Cool, I will take some tonight if I get home in time. If not tonight, then very soon.

 

[shaft311]

Here we go.

The bottom sub is a Celestion Truvox 1530. - $130 sub

The top speaker is a Celestion TF1525CX - You can buy it seperately on Warwick's site, but Celestion doesn't offer any specs as it's essentially Warwick's product.

It sounds FANTASTIC. I got my Hellborg pre and Crown Macro-Tech 2402 set up today, and along with my Hi Cab its LOUD and sounds unreal, seriously.

Anyway,

The pics:
Outside:

Outside:

Top speaker

Looking through the top port on into the bottom (obviously upward firing):

Looking through the top port into the underside of the bottom woofer:

 

[shaft311]

I e-mailed Celestion about the top coaxial speaker because I could not find specs online.

Here is the e-mail exchange:

Hi Chris

You are correct, the TF1525CX is a special design for Warwick. Unfortunately due to customer confidentiality I am unable to comment on the design or the performance of the unit and you will need to contact Warwick about it as, in essence, it is a Warwick product not a Celestion one.



Best regards

Doc

_________________________

From: Chris Havron
Sent: 19 April 2013 15:01
To: drdecibel
Subject: Info about TF1525CX

Hello,

I recently purchased a Warwick Hellborg Big Cab bass cabinet, which has two 15" Celestion speakers: A Truvox 1530 and a TF1525CX. I can find plenty of info online about the 1530, but can't find any info about the TF1525CX. My understanding based on Warwick's literature is that this is a custom speaker developed between Mr Hellborg and Celestion.

What information can you provide me with regarding this speaker?

Thank you!

Chris Havron

 

[Mr. Foxen]

Is the lower speaker between two pairs of ports then? So effectively in two ported enclosures of different volumes?

 

[shaft311]

Yes, that is correct.

Honestly the bottom speaker is a bass/mid speaker and the cabinet does not have super powerful bass. I guess it is supposed to be more of a studio monitor sound than a booming woofer. One of my Avatar B210s creates more powerful bass than this cabinet, but does not sound as clean.

If it didn't involve sawing the cabinet apart, I'd consider replacing the bottom driver with a true 15" bass woofer to get some more bottom end out of it.

In the end, if I were doing all this again, I'd just buy the Club Cab which is the top coaxial driver in a cabinet by itself, and then any kind of 15" or whatever size you want woofer cabinet for the more powerful bass.

 

[Mr. Foxen]

With all the weird alignment, a different driver would probably make a mess rather than more bottom. Top speaker in its own compartment then?