Woofer decision questions?: ESS Heil project

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Looking for some first hand experience and feedback from anyone who has actually tried different (non-ESS) woofers with the larger great Heil.

I want to build my own cabinets and pair up the Heils with a pair of dual eight inch woofers or a good single ten inch woofer. Not certain about running passive radiators, sealed, or ported yet. I may run these on top of powered subs at times, but also want then to sound good without a sub. May use them for standalone 2-way listening on a dedicated amplifier from time to time. A few decades ago, I use to have a set of both AMT Monitors and AMT 1Cs, both with 12" woofers and passives. They sounded good for their time, but I always desired a smaller, faster set of woofers to pair with the larger Heil, and a sub to go along with it.

I acquired a set of 1C Heils to use on this project, and recently picked up a set of NOS crossovers from the original AMT Monitors; just for reference and study. I might even try them to start to see how far off they are. I've read through various threads where many have tried and recommend the Eminence 1040SF woofer with some success with the stock AMT Heil crossovers. Found a a few comments on using the paper Dayton Classic Series II 10" woofers but nothing real telling yet. One guy commented on possibly using the Dayton RS225s, and another member here who tried a pair of 9" fostex in dipole configuration.

My original idea was to run a pair of 91.7db 8" 8ohm paper woofers in parallel for a 4hom load. I would like to try starting out with the stock adjustable, bi-ampable AMT factory crossovers. Crossed at 1200hz. I know it won't sound great, but its a starting point. Not sure yet if I want to run sealed, ported, or passive radiators yet. Thanks in advance for your feedback.

Questions, what would be more recommended using a more basic mainstream woofer vs. an exotic:

A) Two 8" Dayton Classic Series II woofers at 91.7db with one large Heil
B) One 10" Dayton Classic Series II woofers at 92db with one large Heil
C) Other recommendations, any real proven woofers to run with Heils?
 
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I always thought a DiAppolitto style dual woofer set-up would be cool, with an open section for the Di-pole effect....with the open space however I would tend to think the symetrical lobing would be fouled up & not work right.

_______________________________________________________Rick.........
 

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Hi Richard,
Cool. You may have seen this before but your concept reminds me of something similar to the ESS Connoisseur AMT 450 Loudspeaker from back in 2006 - featured in a few different reviews. In fact, that project is sort of where my project idea spawned from once I started researching the idea. The 450 concept had two 7" Seas drivers paired with a heil but the back was blocked off with a front notched cabinet type design. Your picture and idea is interesting because it has an open frame structure with all four sides open for the Heil, more exposed with two separate enclosures for each driver; whereas the 450 speaker design had the rear closed off behind the Heil and the cabinet was visually presented as one piece vs. split like yours. Funny you mentioned this, I recently made a steel frame structure and kind of thought about something once like you have shown here. I've read if you do this, apparently some say you need to have the woofer drivers as close together as you can to the Heil in a D'Op configuration. i.e not much gap in the center between the two drivers and the Heil itself. Not sure how much truth there is to that without some comparative listening tests. I sort of tried something already and failed with two poly Vifa 6.5' woofers and it sounded okay, not great. I may have tried the wrong driver type and size always wondering if I would need to try much improved dual 7s or probably dual 8s instead next time. I keep reading lots of references and recommendations to use "paper woofers" with the Heils. I then started looking back at Scanspeak, Peerless, and even some Morels too, and then found many references to using the single and larger 10" 1040sf woofers again. This is what made start thinking there may be a "known" reason some just run larger woofers with the Heil.

There seem to be more people building 2-ways with a larger 10" woofers and a Heil than dual woofers with a Heil like I'm still considering doing with dual 8s this next time. Did some reading on the Parker Audio speaker with a Heil which had a Poly 10" woofer and the Planet-10 speaker Dave did with dual Fostex 9" woofers in a di-pole config. All fun and interesting ideas; but not seeing many duals yet in D'Op configuration. May be a good reason for it ???, or its really hard to do right I would guess. This is partly why I'm trying to figure out as others have possibly "been there and done that already" and know why not. :) I keep researching it, still hoping to learn from others who have actually tried this before either way, and failed or succeeded with either configuration.

As to my original question, what woofer size and type were you thinking in your particular concept pictured above (dual 6,7,8,10s or)?
 
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10s'........I was thinking applying some super absorptive cork panels on the inside of the open space where the Heil resides...cutting down on reflections....perhaps one could make the baffle somewhat shallow & wide to minimize the effect...I'm just going on WAG...or perceptions of how it "should be" Do you have an original 'Big' Heil or one of the reproductions?
I have indeed heard the Heil to be "fast"....whatever that means...I'm assuming they are talking about transient response..& a lightweight paper cone seeming to match up best.


_______________________________________________________Rick........
 
Might take the plunge try a pair of these Peerless 830869s in Dual 8s per speaker. Was going to try the Dayton Reference Series 8", but these Nomex HDS woofers from Peerless might be an option too. I like what I read about these from different reviews, "not directional like the Eminence", "more open soundstage", "smooth..". We'll see if I try them. Positive or Negative Feedback all welcome from anyone who has actually tried these before.

Use for this pair of speakers:
A) 2-channel listening primarily. For those rare days, with no subwoofers on. Hoping for 35hz, at least 45hz.
B) 5.1, 7.1 Home theather use (rare). Preamp cutoff at 45hz up. Have dual custom Dayton 12" subs now for subsonic bass <45hz.

Have, for this project:
- Big Heil from older AMT 1C line, not new Heils.
- AMT Monitor crossovers; biamp option, adjustable (just as a starting point)
- Factory crossover at 1200hz. Has +/- db presence controls; bi-ampable option on this x-over. Will mess with these for a while at first.

Need/Future:
-Woofer selection. Considering 8" Peerless below.
-No cabinets yet.
-Future Crossover; if this does not work.
-May bump mid two way crossover point to 1500hz or 2000hz later.
-Would like these to do an honest 45hz up for audio and HT, at least.


Tymphany Peerless specs:
http://www.tymphany.com/files/HDS-P830869 Rev1_0.pdf

Some enclosure data I found, for suggested box alignments:
-Sealed box of 15 liters (0.5cf); F3 of 70Hz
-Vented box of 31 liters (1.1cf); F3 of 43Hz; 2" port by 2.75" long

Photos:
3cb77317.jpg


An externally hosted image should be here but it was not working when we last tested it.


This is the current gameplan until a better idea comes up; it always does. Narrowing it down soon though. Thanks. :)
 
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Dayton ST255-8 Excellent Choice

Old thread.
I have used a number of different woofers in my Super AMT3 project-including the mentioned OCS 1040SF.
The best combination I have found in this project (and suitable for a custom build) is the Dayton ST255-8, and the PE Aura NS6 2558A, as the transition driver (mid woofer).
12db crossover @ roughly 250 and 700/1k.
The Dayton is a excellent woofer, efficient, with excellent transient response and low distortion/coloration and a flat response in it's intended range and a excellent match for the Heil.
The Aura carries these same traits-clear midrange and excellent mid bass weight, and transient response, and razo flat repsonse in it's intended range.
These drivers work well with the stock AMT3 cabinet, but the Dayton's works best with 2 x 3" ports 6"L.
Adding low ESR poly caps and large gauge low ESR air coil inductors (especially the woofer coil and cap) will increase efficiency and lower distortion. The large gauge coils make a big difference with the Daytons.
I would also recommend bracing the front baffle between the 2 woofer openings (actually quite easy)-as the Dayton's are more then 2x as heavy as the O.E.-along with Hurricane mounting nuts.
Line the cabinets with foam, and reuse the stock stuffing (roughly 1.5lbs).
I know this goes against the grain of stuffing ported cabinets, but there is some advantages to "resistive loading" a tuned enclosure (a form of Aperiodic).
Volume filling a reflex box
Seems this trick is making a comeback in some current speaker designs.
You could use 2 x 8" woofers and cross one lower/higher similar to the AMT3 crossover design.
The crossover region IMHO is fairly critical with the Great Heil, and using a transition driver IMHO is the best solution-as you fill any midrange holes, yet still have fast and accurate mid bass, and all the tight lower end weight you need.
I like the 10" over the 8" as they will also work well in larger rooms- and negate needing a sub woofer-which I wouldn't recommend with the Great Heil.
IMHO the AMT3 design is the best blue print for a great sounding Heil speaker.
 
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Nice-you will have to post pictures.
I found on the ESS AMT3 that blocking the front sides of the great Heil improves mid bass response by preventing midrange sound waves from wrapping around the housing of the Heil and causing interference with the transition driver. AMT3's as most ESS speakers have gentle slopes and generous driver overlaps.
The Peerless looks like a nice unit. Paper cones work the best-poly and carbon fiber, etc not so much.
With a 2 way, I would seriously consider a electronic crossover.
 
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