True Subbass

[A9X]

Why limit yourself to JBL drivers? For subs a Maelstrom X18 will eat any of the 224x series or a 2235.

I am looking forward to the "analysis" of Danley's 'rubbish' TH paper. I have found Tom to be one of the least BSers in audio over the years. Funny too how there are a number of TH designs from Akabak or Hornresp out there.

[jcrobso]

Above a certain frequency the driver acts a direct radiator and below that frequency the horn takes over. The C40/C34 are examples of this for home use, they are not sub woofers but can deliver very good clean bass down to about 35 Hz. When I get chance I'll measure on of my C40s.

Tapered horn, last time I checked all horns are tapered. There are many different types of tapers to be sure.

[timc]

Why limit yourself to JBL drivers? For subs a Maelstrom X18 will eat any of the 224x series or a 2235.

I am looking forward to the "analysis" of Danley's 'rubbish' TH paper. I have found Tom to be one of the least BSers in audio over the years. Funny too how there are a number of TH designs from Akabak or Hornresp out there.

Question: I checked that woofer. What is so special about it? Am I missing something?

X18 gives a max output of about 120dB (Not sure in what bandpass)

2242H gives max output of about 126dB (100Hz-1000Hz)



-Tim


-Tim

[4313B]

Why limit yourself to JBL drivers?

My educated guess would be because this is the Lansing Heritage website.

[Ruediger]

Here comes my comment. It is in a pdf document attached to this reply. I took the 1st page of that strange paper and added my comments.

Sometimes it takes little effort to claim bullshit, and it takes lots of effort to proof that the claim is false.

Real heavy nonsense cannot even be confuted: if somebody claimed an UFO had landed in the Amazon region and had kidnapped a parrot to learn the human language from it – how would You confute this?

Ruediger

[Eaulive]

Interesting read, thanks!

[Mr. Widget]

Here comes my comment.

Thanks for taking the time... I find it interesting that many seem to revere Tom Danley. I have never met him and have no idea what sort of person he is... but anecdotally he seems to be a nice guy.

A quote from his website: "Danley Sound Labs is proud of the fact that we make extraordinary products from ordinary components." This is essentially how I used to think of Paul Klipsch. I was always impressed how Mr. Klipsch could take fairly pedestrian parts and make something special out of them. Mr. Klipsch was an amazing inventor and an extraordinary mind. I think Mr. Danley sees himself in this same light, but of the audio papers of his that I have read, I come away scratching my head.

Some people defend his work by quoting rave reviews on the internet... hardly the bastion of objective commentary and analysis.


Widget

[timc]

Some people defend his work by quoting rave reviews on the internet... hardly the bastion of objective commentary and analysis.


Widget

Most people like this have their own small group of fanatic followers. Protecting their investment with fierce conviction.

Some know what they are doing, some don't.


-Tim

[A9X]

Question: I checked that woofer. What is so special about it? Am I missing something?

X18 gives a max output of about 120dB (Not sure in what bandpass)

2242H gives max output of about 126dB (100Hz-1000Hz)



-Tim


-Tim

As the thread was asking about sub-bass, I presumed it meant to deal in the area below 80Hz or so.

Volume displacement determines LF output at a given frequency: the X18 is 33mm one way Xmax, the 2242, 9mm. The Sd are 1182 and 1240 and Vd of 3900cc and 1116cc, a 3.5:1 difference.

My educated guess would be because this is the Lansing Heritage website.

Sure, but does that mean one must limit oneself to thinking entirely within the JBL/Altec box?

I own or have owned a ton of different JBL/Altec drivers and most are very good to excellent, but if another performs better in the area I want then I will use that if I can get it, afford it and the difference is worthwhile. The problem is that the oft quoted JBL Pro drivers are excellent for what they were designed for: high SPL, clean performance >40Hz, which is what is mainly need in pro sound. The X18 was designed for low LF performance an octave or more below the JBL's. It has an excellent motor design (by Dan Wiggins) and great performance for the designed task. I would not use one in a PA application because of the poor efficiency, but in the home they are fantastic.

FWIW, I'm using 2241 in my surround side/rear speakers, sealed and EQ'd to get a nice 40Hz out of them, based upon my friend Terry's experience with a similar PHL driver and enclosure. The mids were originally going to be 2123, but when I compared the AE TD10M to them the AE won. I own the AE and the 2123, and I also own one Mal X18 and plan another.

When everything is finished, I will post details and measurements on my website.

[A9X]

Here comes my comment. It is in a pdf document attached to this reply. I took the 1st page of that strange paper and added my comments.

Sometimes it takes little effort to claim bullshit, and it takes lots of effort to proof that the claim is false.

Real heavy nonsense cannot even be confuted: if somebody claimed an UFO had landed in the Amazon region and had kidnapped a parrot to learn the human language from it – how would You confute this?

Ruediger

I have glanced at it and will give it a thorough read over the w/e when I have time. Perhaps your fourth quoted sentence above will also apply to you? We will see.

Most people like this have their own small group of fanatic followers. Protecting their investment with fierce conviction.

Some know what they are doing, some don't.


-Tim

I am not much of the fanboi type, but I am an engineer and tend to approach claims with the 'prove it' attitude based on long experience. I have a lot of respect for Tom, based upon a few simple things: his LABhorn worked exactly as described, as did the Unity's I bought (Tom's theory, Nick's design), plus a number of people have designed and built TH's using either Hornresp or Akabak based upon Tom's work and they have performed in alignment with the spec. I am also impressed with the fact that over the years on a number of forums he has given a lot of his commercial IP away to DIYers, if you care to read what he says carefully and think about it and ask pointed questions. I appreciate that generosity in the same way I do for Nelson Pass and his amplifier designs (even though I own nor use any I have still learned much from him).

So: "Most people like this have their own small group of fanatic followers."

You mean like brand specific websites and the ardent and single minded followers that often produce?

"Protecting their investment with fierce conviction."

If you read my comments as 'fierce conviction', then you are not actually reading what I am typing, merely overlaying your own prejudice upon them.

[timc]

So: "Most people like this have their own small group of fanatic followers."

You mean like brand specific websites and the ardent and single minded followers that often produce?

"Protecting their investment with fierce conviction."

If you read my comments as 'fierce conviction', then you are not actually reading what I am typing, merely overlaying your own prejudice upon them.

First quote: Yes thats what i mean.

Second quote: No, it had nothing to do with you. Just refering to the same fanatics as above.


-Tim

[Ian Mackenzie]

An interesting thread.

I think an acoustic specification for a particular application needs to be adopted for any comparisons. Otherwise its a war of words.

Regardless any useable sub output below 20 hertz or even 25 hertz requires massive displacement and massive watts.(thousands) . This is perhaps why the commercial offerings use class D amps and very long throw woofers. These can be designed to be acceptable size for domestic use but most true subbass subs are generally designed for use below 40- 50 hertz and they seldom sound good on music above those frequencies.

If you want a universal sub that operates from 25- 140 hertz the JBL 2235H is hard to beat in either modest size vented or bandpass enclosures. The JBL 2245H requires about double the box size.

For those with space and cost no object some of the best diy subs are large infinite baffles with mutiple 15 inch woofers mounted in ceilings / wall and floors. The response of large infinite baffles is very predictable and requires no special tuning.

[4313B]

As the thread was asking about sub-bass, I presumed it meant to deal in the area below 80Hz or so.

Volume displacement determines LF output at a given frequency: the X18 is 33mm one way Xmax, the 2242, 9mm. The Sd are 1182 and 1240 and Vd of 3900cc and 1116cc, a 3.5:1 difference.

The JBL 2242H is "good" to 25 Hz. It has an xMech figure of 25mm which is what most people who care about xMax are really interested in. The xMax figure of 9mm is measured at 10% linearity.

It is not a true subwoofer driver in the sense that the Revel 15 aka JBL SUB1500, JBL W1500H or the new Revel eighteen are.

For those who are fascinated with high xMax and enjoy watching their woofer cones leap out of their boxes there is the JBL 2269H with a maximum excursion, one-way, of 44.5mm

For those with space and cost no object some of the best diy subs are large infinite baffles with mutiple 15 inch woofers mounted in ceilings / wall and floors. The response of large infinite baffles is very predictable and requires no special tuning.

Yes, they can be quite inspiring.

[4313B]

Sure, but does that mean one must limit oneself to thinking entirely within the JBL/Altec box?

Not at all. I'm just thinking that this probably isn't the venue for it. Obviously I could be wrong, you guys can do whatever you want within the limits of the posting rules.

I am not much of the fanboi type

You mean like brand specific websites and the ardent and single minded followers that often produce?

Welcome to the Lansing Heritage Website

Our mission is to record the accomplishments, history and legacy of James Bullough Lansing. While his name may not be known to many, the legacy of his work touches millions of people. That legacy is the genesis of the loudspeaker industry. He was instrumental in the development of the some of the first successful loudspeaker products. The quality of his work resulted in the Lansing name being associated with the finest in sound reproduction technology. His name is carried on in the corporate identity of two companies, JBL and Altec Lansing. The purpose of this site is to pay homage to the accomplishments of the man and his namesake companies.

[spkrman57]

Anyone who has used them properly has found them to be breathtaking.

I know I have been impressed with them in my system back in the day.

The only reason they are gone is I was worried about structural damage to my house with continued use of a pair 2242's in 9 cu ft cabs!!!

Regards, Ron