True Subbass

[Dr.db]

Hi,


I know I just had my 2235h thread on, but I`m wondering If I might be more happy with a monosubwoofer.
Considering that, I`d have ~250liters of netto Volume for one Subwoofer.

This sub shell play from ~100 down to the bottom end.
I would believe the 2235h is still the best choice, but what do you guys think??
Does it even make any sense to put the 2235h in 250liters? Or does a 150liter enclosure allready plays as low as this speaker is able to?

What about a 2240h 18" sub. Would this perform any better in low frequencies than the 2235h? Or is 250liters not enough?



Beside that, which modell for up to 250liters would you suggest?


(not for PA-use, just home-hifi and home-theater )




Thanks a lot and have a nice week,
Olaf

[clmrt]

Do you have WinISD or BoxPlot?

Yellow = 250L tuned to 25Hz.

If you download WinISD, you can see the performance charachteristics for any virtual box you like.

[Flaesh]

http://www.dougronald.com/images/PB010011.JPG :applaud:

[jcrobso]

http://www.dougronald.com/images/PB010011.JPG :applaud:
Could you provide some info?

[Eaulive]

Could you provide some info?

It's the crazy guy with 6 30" Electrovoice and 1/3rd of his basement as a cabinet :screwy::D

http://www.dougronald.com/

[Ruediger]

Hi Dr.db,

You could build a B6 alignment. That is a 6th order system, where the bass cabinet is still a 4th order system, and some external electronics provide an additional 2nd order filter.

It requires ca. 140 liters with the 2235 (I think) and it will go down to 22 Hz (I think).

You should make the port big, and that will require additional length. So the overall volume consumed will be more than 140 liters.

There are several electronic crossovers which can provide the 2nd order filter. The one I know is EV DX38.

Regards Ruediger

[Mr. Widget]

Dr.dB... how big is your room, how loud do you want to play and how low?

The 2235H is an excellent all around woofer but it was never really designed to be a sub. It will work in smaller rooms and in cases where you only need bass to around 30Hz. Alignments and enclosures will affect this to some degree, but the design of the woofer simply does not afford it the xmax necessary to pressurize a larger space at VLF.

I wouldn't use the 2240 but you might consider the 2245 if you don't need to fill a very large room with VLF.


Widget

[jcrobso]

Many years ago that 30" was all the rage. The problem was that EV never put a big enough VC and magnet to really control the cone.
I heard a demo many years ago of the 30" EV with an accelerometer on the speaker cone, this would provide real time feedback to the amp and the amp would make corrections to the signal. This made a closed loop servo system, it did sound impressive, but required a rack full of gear to do the job at the time.
I believe that Velodyne uses this type of system.

[4313B]

you might consider the 2245 if you don't need to fill a very large room with VLF.Is an IMAX theater too big? :p

[BMWCCA]

Originally Posted by Mr. Widget http://audioheritage.org/vbulletin/images/buttons/viewpost.gif (http://audioheritage.org/vbulletin/showthread.php?p=271604#post271604)
you might consider the 2245 if you don't need to fill a very large room with VLF.
Is an IMAX theater too big? :p

:rotfl:

http://www.mye28.com/images/smiles/popcorn.gif

[toddalin]

When an 18" just isn't enough? No affiliation.

http://losangeles.craigslist.org/wst/ele/1492332462.html

[Mr. Widget]

Is an IMAX theater too big? :pNow you know that was an irresponsible post... ;) the IMAX theaters used piles of 2245s and blew them up at an alarming rate... JBL responded by developing the 2242.

Even so, a 2245 in a 250 liter cab will not do infrasonics as well as most modern dedicated sub woofer designs.


Widget

[4313B]

Now you know that was an irresponsible post... ;) Yeah, but it didn't cost anything while I'll bet all those blown 2245H's did. Someone spec'd them.
Even so, a 2245 in a 250 liter cab will not do infrasonics as well as most modern dedicated sub woofer designs.Neither will a 2242H.

[Mr. Widget]

Neither will a 2242H.Hell no... I am not really a fan of it either, but it sure can hurt you before it blows up. :D

...and while I wouldn't spec the 2245 for a theater, IMAX or otherwise, I do find it a wonderful sounding woofer. 4345 anyone? :applaud:


Widget

[timc]

I guess the 2269 would do it if you need to fill a very large room with VLF.

Anyone auditioned it yet?


-Tim

[4313B]

Nope. Maybe someday.

If I remember correctly it is the replacement for the 2245H.

[Zilch]

http://www.avsforum.com/avs-vb/showthread.php?t=1189404

Sorry, 2000 posts.... :p

[4313B]

Sorry, 2000 posts.... :pI wouldn't know anything about that. I got bored and never made it past "I've seen the first drafts of the assembly instructions and anyone who has assembled a bookshelf or desk from Walmart should have no problem building this."

[Zilch]

Yeah, the guy's an obvious hack.

Big problem is how to build a highpass at 10 Hz.... :applaud:

[Ruediger]

The article says it was a "tapped horn". These mystical devices are nothing but scoops with the driver reverted.

Imagine You wanted to build one of these Fostex or Lowther scoops. You don't have the height which is required but You have plenty of depth. You rearrange the folded horn such that it fits into a cabinet with little height and plenty of depth. The horn mouth and the driver will now be close together.

Now You revert the driver such that the magnet points to the outer side of Your box. That has the advantage that the driver can dissipate the heat more easily. The midrange radiation will suffer, but as long as You use this thing for bass only that is not a disadvantage.

Voila! You built Your 1st "tapped horn"!
Ruediger

[Eaulive]

Getting onto the best part about this 11 hz is that its outdoor 1 meter measurement with 1 watt of input gave a sensitivity of 90 db at that 11 hz. The rolloff going up the frequency spectrum puts it at 100 db with 1 watt at 25 hz and an upper frequency of 110 db with 1 watt input at 80-100 hz.

Assuming that 110dB efficiency at 100 Hz is true, it yields a frequency response of 10 to 100Hz +/-10dB.... not exactly flat :blink:

20dB difference over slightly more than 3 octaves.... sheesh!

[jcrobso]

If you have ever seen a 32' organ pipe that has a fundamental of 16hz you understand what I mean.

[Zilch]

Assuming that 110dB efficiency at 100 Hz is true, it yields a frequency response of 10 to 100Hz +/-10dB.... not exactly flat :blink:

20dB difference over slightly more than 3 octaves.... sheesh!The issue is infrasonics.

There they are, bigger'n elephant dung, DIY for $1000.

[Manage to taste.... :D ]

[Eaulive]

The issue is infrasonics.

There they are, bigger'n elephant dung, DIY for $1000.

[Manage to taste.... :D ]

I have a small cabinet with a cheapie 15" here that can do the same thing, it's tuned to about 15Hz (unintentionally with a way too long port) and it can shake the doors with a couple of watts.
I say 15Hz but I maybe wrong, it's just the point where the cone has the less displacement for a given input, actually it barely moves at that frequency.
It's maybe not even 20dB down from 100Hz. :D

The mechanical resonant frequency of the woofer in the box is about 4Hz, no kidding! If you give a swing to the cone, it bounces three or four times, slowly, like if it weigh a pound.

Does not sound all that good though :barf:

[Don Mascali]

"Does not sound all that good though :barf:"

I think we get down to "The Laws of Physics Apply".

There is a reason for the big boxes, I am rather fond of 4645C's my self.

[short_circutz]

The article says it was a "tapped horn". These mystical devices are nothing but scoops with the driver reverted.

Imagine You wanted to build one of these Fostex or Lowther scoops. You don't have the height which is required but You have plenty of depth. You rearrange the folded horn such that it fits into a cabinet with little height and plenty of depth. The horn mouth and the driver will now be close together.

Now You revert the driver such that the magnet points to the outer side of Your box. That has the advantage that the driver can dissipate the heat more easily. The midrange radiation will suffer, but as long as You use this thing for bass only that is not a disadvantage.

Voila! You built Your 1st "tapped horn"!
Ruediger

Well, almost, but not quite the whole story.

Here's a link to Tom Danley's white paper on tapped horn technology.

http://www.danleysoundlabs.com/pdf/danley_tapped.pdf

And if you look at the tapped horn products that he designed, they're not even close to a scoop type design.

http://www.danleysoundlabs.com/tapped_horn.html

From the website:


Tom's innovations have been utilized in projects ranging from ground zero bombing simulation and active noise cancellation of jet engines to critical listening mastering studios, high end home theatre and houses of worship around the world.

[Ruediger]

Hi Short Circutz,

lets start with a few pictures 1st. I hope I get the order of pictures and text right.

Here comes the Phonogen scoop. One might consider the driver to be positioned a bit in the horn. The phonogen is a rearloaded horn. Nobody has ever used a weird theory to explain it's behaviour.

Next is a variant where the driver has moved a bit more into the scoop. This thing is claimed to be a Tapped Horn. It looks ***very much*** like the TH MINI from the 2nd link.

Next is a variant where the driver has moved to the other side of the scoop. This thing is also claimed to be a Tapped Horn.

In Danley's paper there is no drawing of a Tapped Horn. Moving target ...

The paper itself is a weird mixture of true and false sentences, and of lots of false and illogical conclusions. It is snakeoil. Bull....

I will prepare an annotated version of the 1st page of this rubbish paper and will post that here. Give me a few days. I need strong nerves for that.

Ruediger

[Dr.db]

Hi,


my livingroom is about 30m² of size and I won`t play very loud. Just average and a little above that..

Maybe a 2235h will be right with its 30hz for Music..!?

Would a 2226 perform the same? How about enclosuresozie for that one?



Thanks a lot!!

[Ruediger]

Hi Dr.db,

the 2235 and the 2245 will lead to very similar alignments, the box for the 2245 will be larger, and the 2245 can move more air with less distortion than the 2235.

The TS-parameters are:
for the 2235: fs 20 Hz, Qt 0.25, Vas 460 liter
for the 2245: fs 20 Hz, Qt 0.27, Vas 820 liter

If You use a passive crossover then the series inductor will have a DC-resistance which will make the Qt become larger, lets say 0.3 in both cases.

With this value for Qt You index into Thiele's tables and pick the following values:

f3/fs is the -3db corner frequency by the drivers resonance frequeny, and it will be the same for both drivers, because fs is the same.

f3/fb is corner frequency by box resonant frequency. You wouldn't care if they were different, but they are the same.

Cas/Cab which is Vas/Vab is a factor which tells You how big the box needs to be. Vab = Vas/factor, that means box size is directly proportional to Vas.

Alignment No. 4 in Thiele's table is a QB3 alignment,
f3/fs = 1.45
f3/fb = 1.18
Cas/Cab = 2.95
Qt = 0.303

Alignment No. 15 in Thiele's tables is a B6 alignment, You need some external electronics for that,
f3/fs = 1.0
f3/fb = 1.0
Cas/Cab = 2.73
Qt = 0.299

You should also have a larger vent for the latter alignment, and that will need to be longer, and thus consume some more volume.

The above parameters show You what You can expect. One can always optimize the parameters with a suitable program, such that Qt does not need to be bigger.

First make up Your mind and decide what box You want to build. Also calculate a crossover and check how expensive it will become. It may well be that an active solution is cheaper. Any passive volume correction for the low mid driver will spoil that driver's Qt (unless You use a transformer(auto-transformer)).

Then ask somebody here to run a program for Your favourite design.

Regards Ruediger

[Eaulive]

Hi Dr.db,

the 2235 and the 2245 will lead to very similar alignments, the box for the 2245 will be larger, and the 2245 can move more air with less distortion than the 2235.

The TS-parameters are:
for the 2235: fs 20 Hz, Qt 0.25, Vas 460 liter
for the 2245: fs 20 Hz, Qt 0.27, Vas 820 liter

If You use a passive crossover then the series inductor will have a DC-resistance which will make the Qt become larger, lets say 0.3 in both cases.

With this value for Qt You index into Thiele's tables and pick the following values:

f3/fs is the -3db corner frequency by the drivers resonance frequeny, and it will be the same for both drivers, because fs is the same.

f3/fb is corner frequency by box resonant frequency. You wouldn't care if they were different, but they are the same.

Cas/Cab which is Vas/Vab is a factor which tells You how big the box needs to be. Vab = Vas/factor, that means box size is directly proportional to Vas.

Alignment No. 4 in Thiele's table is a QB3 alignment,
f3/fs = 1.45
f3/fb = 1.18
Cas/Cab = 2.95
Qt = 0.303

Alignment No. 15 in Thiele's tables is a B6 alignment, You need some external electronics for that,
f3/fs = 1.0
f3/fb = 1.0
Cas/Cab = 2.73
Qt = 0.299

You should also have a larger vent for the latter alignment, and that will need to be longer, and thus consume some more volume.

The above parameters show You what You can expect. One can always optimize the parameters with a suitable program, such that Qt does not need to be bigger.

First make up Your mind and decide what box You want to build. Also calculate a crossover and check how expensive it will become. It may well be that an active solution is cheaper. Any passive volume correction for the low mid driver will spoil that driver's Qt (unless You use a transformer(auto-transformer)).

Then ask somebody here to run a program for Your favourite design.

Regards Ruediger

I would love to grasp these concepts as easily as I grasp antenna concepts, wich are also a tool to convert electrical signals into useable waves (in this case electromagnetic instead of accoustic) but I'm a ham, not an audio guru. :D

Lately I'm obsessed with building a set of 4520s and I'm wondering if there's a program that could simulate this rather complicated box, loaded with different drivers.

I would like to see if the original design could be slightly optimized (not modified, I still want them to be 4520s).
For antennas there are some programs that simulate and model the electrical and electromagnetical behaviour of any given shape of any given conductor and material so one can actually see and optimize the performance of even the most complex arrays.
I wonder if there would be something equivalent with electro-accoustics.

Kind of a software where you enter all the internal dimensions of a box, horn shape and all. :applaud:

[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. :hmm:

[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


-TimAs 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. :hmm: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?

RuedigerI 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.


-TimI 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 :rotfl:

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

[Ruediger]

I checked the TS parameters of the Maelstrom X18.

Qt = 0.40
fs = 17.1 Hz
Vas = 383 Liter

From Thiele's tables I pick alignment #6 which is a C4 (Chebyshev).

Qts = 0.415
f3/fs = 0.867
f3/fb = 0.935
Cas/Cab = 1.055

This leads to a box with the following properties:

f3 = 17.1 x 0.867 = 14.8 Hz
fb = 17.1 / 0.935 = 18.3 Hz
Vab = 383 / 1.055 = 363 Liter

The efficiency is 88.4 dB / 1W / 1m.

The corner frequency f3 is too low. There are no signals at 14.8 Hz. This wastes volume or efficiency.

The box volume Vab of 363 Liter is more than that of the 4435 monitor.

The efficiency is very low. Three db means You need twice the power, ten db means You need ten times the power.

Ruediger

[4313B]

Anyone who has used them properly has found them to be breathtaking.Greg's assessment - "They're not of this planet."

[Dr.db]

Hi,


thanks for the massive input. :)


If you are limited to 150 liters of volume, which JBL-driver would be best in between 30-800hz ?


Does a 2226 operates the same as a 2235 ?

[Dr.db]

I`m still wondering which 15-incher I should mount in the cabs.


Will a 2226 perform below ~100hz as well as a 2235h ?

Does a 2220 sound better than a 2226 above ~100hz ?



Thanks a lot for your help and a happy 2010 everyone!! :)

Olaf

[Zilch]

There are no signals at 14.8 Hz.No, huh?

That's not what the uber-bass HT guys believe.... ;)

[Allanvh5150]

No, huh?

That's not what the uber-bass HT guys believe.... ;)

I have 4 2235's. That is quite uber enough for me.

[toddalin]

I have 4 2235's. That is quite uber enough for me.


One may think that until they hear/feel the really deep stuff. :jawdrop:

[Allanvh5150]

One may think until they hear/feel the really deep stuff. :jawdrop:
I have a pair of 18's that go down to 15Hz but they are not what I would call musical.

Allan.

[Zilch]

LFE isn't musical, but it is.... :)

[Ruediger]

I`m still wondering which 15-incher I should mount in the cabs.


Will a 2226 perform below ~100hz as well as a 2235h ?

Does a 2220 sound better than a 2226 above ~100hz ?



Thanks a lot for your help and a happy 2010 everyone!! :)

Olaf

The 2235 will need a refoaming after ca. 15 years, 2206 and 2226 will not.

The 2226 can be equalized to deliver similar performance in a 140 liter enclosure. A decent active crossover (EV DX38 :) can do that.

The 2206 allows to build small satellites with a high WAF. You will need a subwoofer then.

The 2235 allows for a useful B6 alignment (see earlier in this thread).

What I still do not know: what do You mean by "sub"?

If its music then there will be very little material with frequencies below 35 Hz. So an f3 of 35 Hz should do.

If its home theatre then there will be signals below 35 Hz (Godzilla walking through Your room), but You don't need quality for that. A junk subwoofer or a shaker will do.

See posts #6 and #29 in this thread.

Ruediger

[Dr.db]

Hi Rüdiger,


thanks a lot for your post(s)!! :)
Please forget the "sub"; I'm changing my setup to a strictly stereo-system without monosub...


So if very high spl is not requiered I will have same lowbass performance with 2226 as with the 2235....
(...using the EQ.)



How does the 2226 compare to the 2220 above 100hz !? The coneassembly of the 2220 is ~30gr lighter with same BL-factor; but does it really sound noticeable better?
At top their will be 2441 and 2405 running as mentioned earlier....


Regards,
Olaf

[badman]

One may think that until they hear/feel the really deep stuff. :jawdrop:
I'm with you Todd. While the most impactful bass isn't terribly deep, the very very low stuff has a lot of purpose, especially in HT, but overall, it's as much an ambience thing as a "rumble" thing. Big spaces have low frequencies associated with them. They may not be at high level, but they still contribute to the illusion.

[Loren42]

I use two 2235Hs for my stereo 3-ways I built. They each are in a 6 cubic foot (170 liters) vented box with two 3.95" diameter flared ports each 6" long.

The passive crossovers were designed using Leap, but this is the predicted behavior in the above described box:

http://www.mdbq.net/audio/2235_leap.jpg

This 3-way delivers very good quality sound, high SPL, and excellent stereo imaging and staging using a custom built tube amp with two KT88s per channel. No complaints from me as a full-range speaker system

http://www.mdbq.net/trex/t-rex.jpg

It does not get you to 20 Hz, but -3dB is about 28 Hz. If you want something lower I would consider a driver that has a very high xmax, low distortion, and a electrically assisted sealed enclosure.

The other design I would love to try is a transmission line with a 15" or 18" woofer, but you need a pretty large cabinet for such a beast. However, the bottom end would not only be authoritative, it would probably be very high quality audio.

[Dr.db]

Hi,

I got myself two 2235h now.
I'll put them into 5cubs each and I believe -3db/30hz will be low enough....


Thanks for all the info`s,
Olaf

[gibber]

Here comes the Phonogen scoop. One might consider the driver to be positioned a bit in the horn.

The Phonogen is a rearloaded horn. Nobody has ever used a weird theory to explain it's behaviour.

Next is a variant where the driver has moved a bit more into the scoop. This thing is claimed to be a Tapped Horn. It looks ***very much*** like the TH MINI from the 2nd link.

Next is a variant where the driver has moved to the other side of the scoop. This thing is also claimed to be a Tapped Horn. In Danley's paper there is no drawing of a Tapped Horn. Moving target ...

Ruediger



Maybe not weird theory, but weird the horn called "Phonogen" is. Not sure it's a good example of a scoop / rear-loaded horn.
Made of two light-concrete parts held together by a 1.5" thick U-shaped heavy wooden frame, it has mounting arrangements for two 10" drivers on a common front/back axis. The driver visible on the outside towards the end of the horn mouth may or may not be coupled to the bass horn, depending on the version of the Phonogen you are looking at. Here's a drawing, tapped horn or not, don't want to decide


58467

The inside driver front radiates directly into a 2.5 m long bass horn, it's rear sees into a closed box of ca 40 litres (1.5 cu ft). Different from some of the theater horns that Lansing (the man) was involved in, there is no porting of the rear enclosure. This version is a classic front-loaded horn, then. The front driver sees into an 8 litre chamber and fulfils lower-mid duties.


Many Phonogen have an 8cm hole drilled into the front driver's 8 litre rear chanber, opening that chamber into the bass horn exactly opposite the main (invisible) driver's dustcap. In that case, you have two 10" drivers working into the same horn, one of them decoupled from the horn by a lowpass formed by it's 8 litre volume / 8 cm dia opening. Not a textbook rear-loaded horn or scoop, but getting close.

58477



The picture below is of "Phonogen", an early model using LE10a for bass and low-mid duty, LE175 with horn/lens, and 2405. Corrections are invited when i say that this version likely had only the inside LE10a working into the horn.

58469



Here's "Phonogen 1". Have this version in my basement setup. Mine has the 8cm hole (original or later mod, i can't tell). Mid/high was from an electrostatic bent to form a circular column that could be turned for directivity control. Version "1A" (not pictured) had the long side of the cab up and added a second electrostatic plus a horn tweeter similar to the Fane Ionovac. I use only the "1" bass cab with a brace of D.B.Keele's White Whales on top.
58468


Rüdiger's first pic in post #27 is what i believe was the last version ("Phonogen Reference"). I'm almost sure that one would have the 8 cm connecting hole in place (i.e. using both 10" for bass), because a third cone driver has been added for midrange in that box on top also holding the tweeter.


Regards,
Ralph

[gibber]

Rüdiger's first pic in post #27 is what i believe was the last version ("Phonogen Reference").

Just received a message that the above assumption isn't quite correct. Apparently the picture i referenced to shows a prototype only of "Phonogen Reference". The production model had two 5" cones and a dome unit with inductive feedback each for midrange in that svivel-mounted mid/high cab. The tweeter is changed from Braun Ionovac to the ATR version. I was referred to this picture (on the left):

59093

While at it, i realize the speaker on the right is the one mentioned but not pictured in my previous post - Phonogen 1A. More stuff on this extremely compact 100x70x60cm bass horn was kindly made avalable here (http://www.johannes-krings.com/PHONOGEN_1979_1981_AUDIO.pdf) (pdf)

Ralph