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Author Topic: Upper bass-range cabinets?  (Read 12014 times)

Art Welter

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Re: Upper bass-range cabinets?
« Reply #10 on: October 25, 2009, 06:21:48 pm »

That type of phase plug would be very specific to the cone curve.

You might need a "donut" to space the cone further away.

Harbinger as a name has been used by many over the years.

I have heard guys describing Harbingers used in the 70's in England, but never saw them myself.
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Elliot Thompson

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Re: Upper bass-range cabinets?
« Reply #11 on: October 26, 2009, 02:21:21 am »

Craig Hauber wrote on Sun, 25 October 2009 21:38

Art Welter wrote on Mon, 19 October 2009 14:14


Who is the designer / builder?


Not sure, the only label on them is "harbinger" and I don't know if thats a builder, owner (or both) but searching that name brings up nothing related except for a cheap chinese speaker brand.

Here's the compression chamber showing the "phase plug"  The opening above is just a tilt-handle and access into the upper portion of the box which contains the 2" and horn only.
index.php/fa/25727/0/
It is roughly 2.4 cu ft (not including driver volume) and I put a batt of 3" fiberglass in there.



With a depth of 30-inches, they are probably 180-200 Hz horns and, lose their efficiency rapidly under 200 Hertz. Since the cabinet is sealed any means of bass extension is eliminated.

You also have Electrovoice DL 12X that cannot deliver a lot of mid bass without excessive cone movement. The EV DL 12X is actually the old EVM 12L (Lead Guitar) designed to handle more wattage.

Those are two major obstacles that will prevent you from achieving anything under 200 Hertz with high efficiency. You would need to redesign the cabinets and replace those EV drivers with woofers (The EV DL 12X are Lead Speakers) for a lot of mid-bass ranging from 180 – 90 Hertz. Two EV DL 12X sitting in a 2.4 sealed cubic box will give you a –3 dB @ 174.3 Hz.

If you want to stick some cabinets in between, you can go to www.speakerplans.com and, build a few HD 15s. I am not sure if you are looking to create such a configuration in terms of cabinets. However, the harsh reality is those cabinets are midrange cabinets despite looking as if they can deliver a lot of low-midrange/mid-bass.

Best Regards,
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Elliot

Craig Hauber

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Re: Upper bass-range cabinets?
« Reply #12 on: October 26, 2009, 08:57:27 pm »

Elliot Thompson wrote on Sun, 25 October 2009 23:21




With a depth of 30-inches, they are probably 180-200 Hz horns and, lose their efficiency rapidly under 200 Hertz. Since the cabinet is sealed any means of bass extension is eliminated.

You also have Electrovoice DL 12X that cannot deliver a lot of mid bass without excessive cone movement. The EV DL 12X is actually the old EVM 12L (Lead Guitar) designed to handle more wattage.

Those are two major obstacles that will prevent you from achieving anything under 200 Hertz with high efficiency. You would need to redesign the cabinets and replace those EV drivers with woofers (The EV DL 12X are Lead Speakers) for a lot of mid-bass ranging from 180 – 90 Hertz. Two EV DL 12X sitting in a 2.4 sealed cubic box will give you a –3 dB @ 174.3 Hz.

If you want to stick some cabinets in between, you can go to www.speakerplans.com and, build a few HD 15s. I am not sure if you are looking to create such a configuration in terms of cabinets. However, the harsh reality is those cabinets are midrange cabinets despite looking as if they can deliver a lot of low-midrange/mid-bass.

Best Regards,



I'm fine with the midrange, more than fine actually -they get very loud, stay very clean at high volumes and carry for a very long distance!  I don't want to give that up so my original post was about building a quasi-matching low-mid box to get me down to at least 80 or below to cross over to a more true subwoofer like the LAB.
I think it's the Lead Guitar capability of the EV that works so well.  The DL-12's we have in a couple of them are out of SX-300's and are the same as in some of EV's single-12 install series cabinets.  We have no issues with them.

From some rough calculations I could put 2 of those HD-15's on their sides and stacked and the frontal size would be roughly the size of the front of my mid/highs.
My only questions would be how do you build that curve and what model of currently available 15 would give you the best results?
-Also could you trapezoid the cabinet to physically match the tops? ...like this:
index.php/fa/25754/0/
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Craig Hauber
CSA Productions Inc.
Ventura-Santa Barbara CA
www.csaproductionsinc.com

Elliot Thompson

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Re: Upper bass-range cabinets?
« Reply #13 on: October 27, 2009, 10:44:33 am »

Why not pose your question on the HD 15 forum?

When I was 13, I remember watching a carpenter use water to bend a sheet of wood to create a flare. I believe the wood was 5/16 of an inch.

With the amount of users of the HD-15 on Speakerplans, I'm quite sure all your questions will be answered. There is also a dual HD-15 version running about in addition, to another design called I believe "The Wicked One" that was designed specifically to work over the Lab Subs.

Best Regards,


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Elliot

Art Welter

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Re: Upper bass-range cabinets?
« Reply #14 on: October 27, 2009, 11:27:33 am »

Straight approximations of curves work fine, a curve as you show would only require two parts.

If, for aesthetics, you want curves, laminating 2 or three pieces of 1/4" fir plywood bends easy with no special treatment required.

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David Russell

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Re: Upper bass-range cabinets?
« Reply #15 on: January 25, 2010, 03:24:42 pm »

I used four of these Harbinger cabinets in the mid 80's and they were fantastic.  Mine were loaded with JBL drivers and they worked fine for everything from jazz, blues, rock and Reggae, lots of low end, great mid-range and highs.  Two a side were plenty loud in volume with great response.  Two coupled together side by side was the original intention of the company.  I wish I still had them.  Mine used JBL 15" on the bottom.
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Tim Padrick

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Re: Upper bass-range cabinets?
« Reply #16 on: January 31, 2010, 02:51:32 am »

When I was in high school, I did not have any trouble building A-7s until it came to the horn.  My dad suggested (and help with) installing battens the shape of the curve, then bending (and gluing & screwing) 1/8" tempered Masonite as the horn material.  Installation went without a hitch, and it made for a very stiff horn.

Duane Massey

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Re: Upper bass-range cabinets?
« Reply #17 on: February 01, 2010, 01:20:18 am »

To make the curves on my bass horns (and mid-horns) I use a single piece of 3/4" plywood and cut "lines" in the backside every 2-3" that are approx 1/2" deep. Depending upon the plywood this depth can be adjusted a bit to make a decent bend. For the bass horns I do a layer of 3" wide strips of 3/4" plywood and laminate the finished layer on top (lots of glue!).

For years I just laminated sheets of 3/8" plywood (4 layers), and this was structurally great, but I just didn't like the final appearance, as 3/8" is hard to find in a finished grade.

As far as the curve, send me a PM and I'll be glad to give you some suggestions based on my experiences.
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Duane Massey
Houston, Texas, USA

Robert Harker

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Re: Upper bass-range cabinets?
« Reply #18 on: June 30, 2010, 12:58:05 pm »

They are indeed Harbinger speakers.  The phase plug is unique to the Harbinger design.

Harbinger was a San Francisco Bay Area company located in Menlo Park in the same building as The Music Annex recording studios.  Mark Wayne and Gil Deliso were the principals.  Mark was the designer and Gil managed the shop.  Mark's designs competed with John Meyer (Meyer Sound) and John DeLoren (Apogee Sound) designs.  They were very popular in the bay area and used by Bill Graham Productions for a long time.  Unfortunately they hit the market at the wrong time.  Most sound companies were building their own speakers and were not willing to pay for high quality designed and manufactured cabinets.  I gather that they ran out of money and the company failed.  They were in business from 1982 to 1985 or so.

The horn flare employed was an oddball shape.  They were referred to as "cat's eyes".   Your speakers were the model 228 mid-high cabinets in their array-able model 828 mains.  Each of your cabinets would sit on top of a single 18" model 805 "cat's eye" bass bin.  Harbinger may have also made a double 18" cat's eye" bass bin but I can not find any record of them.  The original designs used all pro JBL components so the EV drivers are wrong.  They would have used JBL 2020 12" drivers and a a 2440 or 2441 2" driver.  I think the high frequency horn is the same design as their 1208 standalone horn.

One of the hallmarks of Harbinger designs was to physically time alline all the speakers in the system.  This was true of their horn loaded fronts and their JBL k130 / 2410 floor monitors.  Harbinger also balanced the efficiency of the components in a cabinet so you could use a passive crossover without an L-pad.  At the time Harbinger was state of the art in speaker design.

As to what to do with these?  I would replace the drivers with the original JBL drivers.  I would then try an find six 805 18" bass bins to put under them.  If you can find them, I suspect they would be cheap.  The 18" bass bins would fit right in between the mid-high boxes and a bunch of LAB subs.  These speakers really need to be used in arrays.  They are a long throw design and don't really start to sound good until you are at least 50 feet front hem.  But then they really rock.

RLH
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