[Jon L]

I use the Eminence Alpha 15" woofers which are probably not as good as the Lii Audio W-15

I bought some Goldwood GW-1558 15" woofers which some report they prefer to Eminence for open baffle bass. 
On your speakers, I don't mean the triangular metal shelf support, but the long black beam that the support attaches to.  Is it not metal but wood beam painted in black? 

0212251907 by drjlo2, on Flickr

[Poultrygeist]

One reason the Alphas are so popular for open baffles is that they don't require EQ.

The braces are wood painted black.

[jk@home]

This Lii set up reportedly had some good bass. 

https://www.stereophile.com/content/davina-loudspeaker-prototype

One of these days I want to try the "open baffle, dual-opposed (force cancelling) configuration". I originally wanted to build it into the OB I have now, but didn't due to the low pass limitations. That wouldn't matter for a sub. The perfect app would be a coffee table sub.

[Poultrygeist]

I can only imagine how good they would sound in a larger room pulled out from the walls.

[Poultrygeist]

I enjoyed these until I ran out of space. The 8" Zenith Alnico's are special but alas they had to go into storage. The 16" woofers are from a pair of Sansui speakers left on the curb. After I freed them from their cramped boxes I was surprised at how well they performed in open baffles.



 

[Poultrygeist]

Eminence Alpha 15a specs @ $144.95 each

QTS - 1.26 ( higher the better and low QTS requires EQ or box enclosure )
Xmas - 3.8mm
Sensitivity - 97

Goldwood GW -1558 specs @ $67.18 each

QTS - .63
Xmas-  3.9mm
Sensitivity - 95.6

[opnly bafld]

The higher the better, yes if you like slow and loose bass due to a weak motor.
There are many good options with a QTS of 0.6 up to 0.9 that don't require eq.

My current 12" OB subs @ less than $50 each destroy the Apha 15a in sq

QTS - .82
Xmax - 8.5mm
Sens. - 89 dB, bi-amping not important - Alpha sens. is 97 if including a 10 dB peak at 2,000 Hz, 94 dB if you actually look at measurements.
FS - 32 Hz (Alpha 41 Hz)

A friend has a pair of 15" AE IB drivers (bought years ago when they were 1/2 $ of what they are now $$) and last summer got 4 - Alpha 15a for $0.
He tried the Alpha's and then A/B'ed with the AE's using plate amps, not even close. Bye, bye Alpha's.

[FullRangeMan]

Qts too hi make the bass too soft,
My personal taste are qts = 1.5

[opnly bafld]

Qts too hi make the bass too soft,
My personal taste are qts = 1.5

It's fun when you joke around. 

[FullRangeMan]

It's fun when you joke around. 

Not a joke intended. 
Here they say the sensitivity are 94dB.
https://loudspeakerdatabase.com/Eminence/ALPHA-15A

[FullRangeMan]

https://loudspeakerdatabase.com/Eminence/ALPHA-15A

Sens. - 89 dB, bi-amping not important - Alpha sens. is 97 if including a 10 dB peak at 2,000 Hz, 94 dB if you actually look at measurements.
FS - 32 Hz (Alpha 41 Hz)

The Alphas were a great option when it cost $69 at PE, now at $145 not funny.
Do you have the Alpha 15A real dB graphic measurement ?

[Poultrygeist]

Some years ago I bought 3 pair of Alphas at $59 each. I took a pair out of storage last summer that I wasn't using and sold them for $200. Folks are evidently buying them as demand has made their price escalate. Several OB companies have used stock Alphas as well as their own Alpha based version including Hawthorne, Pure Audio, Emerald Physics, Tekton, Caintuck and the list goes on.

I'm sure OB companies use the GW but I haven't found any yet. 

Would love to hear the W-15 which is one of a few purpose built OB woofers I'm aware of.  I may eventually buy a single.

[jk@home]

I have 4 of the (old) AE IB15" drivers in two IB manifolds. Got them for $125 each back in 2011. I had just missed the 4 for $100 each sale. 

I'm assuming they have improved a bit since then.
https://aespeakers.com/product-category/ibht-woofers/

[FullRangeMan]

Some years ago I bought 3 pair of Alphas at $59 each. I took a pair out of storage last summer that I wasn't using and sold them for $200. Folks are evidently buying them as demand has made their price escalate. Several OB companies have used stock Alphas as well as their own Alpha based version including Hawthorne, Pure Audio, Emerald Physics, Tekton, Caintuck and the list goes on.

I'm sure OB companies use the GW but I haven't found any yet. 

Would love to hear the W-15 which is one of a few purpose built OB woofers I'm aware of.  I may eventually buy a single.

What do you think on 2 voice coil woofers as Lii ?

[Poultrygeist]

6 Moons did a review of the Emerald Physics which featured double Alphas and a Beta with a compression horn ridding piggyback.

https://6moons.com/audioreviews/emerald/1.html

[Poultrygeist]

The AE's are another great purpose built OB woofer. MJK uses two AE's per side in H-frames with Lowther's on top.

[opnly bafld]

EP was14 years ago - no longer available.
Hawthorne didn't use Alpha's for their Augies (bass drivers).
Caintuck sells 15" and 12" Alpha's, from their website "15" driver goes lower - 12" driver is quicker and tighter". I want low, quick, and tight
Tekton uses Eminence drivers, but I don't know which ones since Eminence makes a lot of drivers and you can quantity order them with changes.
Tekton's latest OB speakers are less than awe inspiring. 

There may be a few that still use Alpha's or a driver based on them with mods. 

A lot of choices in 2025 for OB bass. 

[Poultrygeist]

Emerald Physics OB 's were designed by Clayton Shaw who started Spatial. His early models at Spatial featured Alpha woofers.

Eminence made the drivers for Hawthorne.

I noticed you finally posted a picture of your OB's. Glad to see you went with the Betsy's and Goldwoods. The Betsy's are a great choice for one's introduction into open baffles.

[opnly bafld]

Emerald Physics OB 's were designed by Clayton Shaw who started Spatial. His early models at Spatial featured Alpha woofers.

Eminence made the drivers for Hawthorne.

I noticed you finally posted a picture of your OB's. Glad to see you went with the Betsy's and Goldwoods. The Betsy's are a great choice for one's introduction into open baffles.

I know who designed the EP's (talked to him at RMAF in the early days) and also know that he no longer uses Alpha's.

Eminence made the Augies to Hawthorne's specs, I had a pair they were not Alpha's.

I made them because the Betsy's were given to me and at first I was going to just pass them on, but decided to use them instead, the Betsy's are a great choice for anyone.  Nice try, but I did not use Goldwood drivers, not that there is anything wrong with them.

The OB's are sitting idle because the Cornwall's are back in the main system. I'm thinking of changing the Betsy out for a driver I can build a box around so I can place them closer to the wall and then use them in my small room.

Glad to see you posted the same old pictures 100 more times (with the same rhetoric  ), I think you even posted a new picture. 

[opnly bafld]

mick wolfe

Sounds like you mostly have it figured out.
Do you have any thoughts/plans about giving the full range drivers bass support?