18" woofers

[Jakob]

This weekend I've tried an 18" -woofer for use with my 250 ti's. It's a non-JBL PA driver in a box tuned to about 40 Hz. I thought it would sound terrible, but no, it sounded really good. It seems it has a quick response, and though tuned at a rather high frequency, still seems to have a lot to give down to 20 hz.

Now I'm wondering: Why should I go for the 2245? I've been told that the 2245 is a rather "slow" driver, is this true? Would the 2241 or 2242 be a better driver for me? I want deep bass of course, but not in exchange for the tightness.
I love the bass in the 250 ti's, I just want more if it!

B.R: Jakob

[4313B]

The 2242H and 2245H are excellent 18" transducers. If the 2245H seems "slow" then someone needs to look at a change in amplification. There is nothing remotely "slow" about a 2245H. The LE14H-1 in the 250Ti is considered one of the finest JBL low frequency transducers ever made. That is what you are trying to augment, and dual 2245H's would be an excellent choice.

"I love the bass in the 250 ti's, I just want more if it!"

Yep, I know exactly what you mean...

[boputnam]

Originally posted by Giskard
If the 2245H seems "slow" then someone needs to look at a change in amplification. And by that, I think you mean increased damping factor / output impedence and not necessarily watts - 'cause we know how efficient these badboys are! :yes:

[speakerdave]

There's also the reality that woofers sold as separate drivers will often be heard poorly cabineted and the driver will get tagged for the fault.

David

[4313B]

Definitely.

[scott fitlin]

If your looking at the 2241 or the 2242 I would choose the 42, because it has better midbass transient response, and in the proper cabinet, will have that fast snap you are looking for! The 42 is an excellent high power 18, while I have listened extensively to the 2241 and dont care much for that model!

The 2242 is also one of the MOST reliable drivers, and will never blow, unless you really , really abuse them!

In a properly tuned cabinet, with the proper power, the 2242 will rock your world!

[Jakob]

I wasn't sure before, but You are ALL in fact working at JBL's sales department, right? ;)

Well, since JBL chose the 2245 for the B460, what can go wrong?

Are they easy to overdrive compared to f.e. the 2242? I don't want the woofers to go "pop" against the backplate just when the fun begins.

I'm thinking of driving them with a JBL/Urei 6290, this should be enough power, right? My only concern is that this amp has a 2-step fan, and I have no idea how noisy it is?!

Any other PA amp you could recomend?

Thanks for Your input!

[4313B]

Originally posted by Jakob
I wasn't sure before, but You are ALL in fact working at JBL's sales department, right? ;)Well actually, no.


Originally posted by Jakob
Well, since JBL chose the 2245 for the B460, what can go wrong?The 2245H was also used in the original Synthesis subwoofer and the 4645 subwoofer. It has since been replaced by the 2242H in both of those applications.

[Niklas Nord]

Are JBL going to release some new 18" driver soon?
When will we se a replacement for the 2242?


How about these new Vertec-subs ? Is there not a new
18" driver there?

[4313B]

Niklas, I asked and was told there is no replacement for the 2242H in the works. It will remain the premium go-to 18-inch transducer for "best of class" VLF applications.

[Oldmics]

"Niklas, I asked and was told there is no replacement for the 2242H in the works. It will remain the premium go-to 18-inch transducer for "best of class" VLF applications."

However

There is a newly designed speaker (2268H) using the DCD technology.

These are in the new SRX 700 Series speakers.Specifically the SRX 718S.

Makes me wonder what sales is up to?,and what will ultimatly be the best?

I have seen the new series but have not seen the driver or heard any of them.

Follow the link for a peek.

Oldmics


http://www.jblpro.com/srx700/index.htm

[4313B]

"SRX718S - 18" subwoofer"

Something tells me those won't be replacing the 4645C any time soon. I could be wrong though...

*****

It appears I wasn't. The 2268H is listed as the replacement for the 2241H as of 22-MAR-2004.

Re = 5.3 ohms
Fs = 33 Hz
Qts = 0.36
Qms = 3.8
Qes = 0.39
Vas = 328 liters
no = 2.8 %
Sd = 0.1269 sq m
Mms = 168 grams
Bl = 21.5 T*m
Pe = 800 W

Xmech = 23 mm (spider bottoms on gap sleeve)

Very nice transducer! :yes:

[John Warren]

Niklas, I asked and was told there is no replacement for the 2242H in the works. It will remain the premium go-to 18-inch transducer for "best of class" VLF applications."



18" McCauley 6174

Fs 20Hz
Vas/Qes = 1928
n =.66%
94dB/W/m
1kW RMS thermal dissipation
ship wt. 45lbs.

[4313B]

Why quote me and then post a McCauley driver? JBL isn't using McCauley drivers to replace the 2242H.

[scott fitlin]

Originally posted by John Warren
Niklas, I asked and was told there is no replacement for the 2242H in the works. It will remain the premium go-to 18-inch transducer for "best of class" VLF applications."



18" McCauley 6174

Fs 20Hz
Vas/Qes = 1928
n =.66%
94dB/W/m
1kW RMS thermal dissipation
ship wt. 45lbs. Have you ever heard the McCauley 6174?

If you heard it you might not post about it so fast! Inefficient, 20hz rated but you dont really get anything above 60hz out of it. Takes a ton of power, and needs a ton of power just to do something. Lacks punch, lacks just about everything!

This McCauley woofer was being featured in a pro folded horn, called Bassmaxx, to be blunt, it sucked!

[4313B]

I only know one thing - if the McCauley was the go-to driver then JBL would build it.

[4313B]

6174
Single 18"
15Hz - 800Hz

Performance
Freq. Response (-3dB) 15Hz - 800Hz
Recommended Enclosure Volume 6ft³
169.9L
Power Handling (RMS)
Full Range 800W
Max Peak SPL
Full Range 129.031dB
Max Continuous SPL
Full Range 123.031dB
Sensitivity
Full Range 94dB
Theile Small
Free Air Resonance (Fs) 20
4Ù DC Coil Resistance (Re/Dcr) 5.6Ù
Electrical Losses (Qes) 0.38
Mechanical Losses (Qms) 2.9
Total Quality Factor (Qts) 0.34
Equivalent Volume of Air (Vas) 25.9ft³
733.41L
Effective Piston Area (Sd) 199in.²
1283.87cm²
Excursion -- Max BL (Xmax) 0.6in.
15.24mm
Volumn Displacement (Vd) 200in.³
3.28L
Inductance of V.C. (Le) 1.1mH
BL Factor 15.3Tm
Effective Moving Mass 0.222oz.
6.29g
Nominal Efficiency 0.0066%
Flux Density 13500 gauss

Their TS parameters are kind of jacked up. Can't really have an EMM of 6.29 grams. According to all their other specs I get an EMM of 202 grams. I see what you mean Scott about them needing a lot of power - 0.0066% efficiency is pretty lousy.

Recommended enclosure volume is 6 cu ft which is half of what BB6P recommends.

6 cu ft tuned to 25 Hz
red = McCauley
grn = 2242H

[4313B]

6 cu ft tuned to 25 Hz
80 Hz 24 dB/octave LR LP
red = McCauley
grn = 2242H

[4313B]

The McCauley really needs something like 11 cu ft to do what the 2242H does in 8 cu ft.

[4313B]

With LP
red = McCauley in 11 cu ft @ 25 Hz
grn = 2242H in 8 cu ft @ 25 Hz

[4313B]

Then the Revel15 comes along and does what they both do with only 4 cu ft albeit much less efficiently. Same bandwidth though. I know which one I'm going to use in my house and which one I'm going to put in the Cineplex.

[4313B]

Anyway... whatever...
Use whatever you guys want.

[John Warren]

>>>Scott F said:

>>>>Nothing above 60Hz.

The 6174 is a subwoofer (sub = below). It is designed to operate in the 16-32Hz octave range.

>>>>>Takes a ton of power, and needs a ton of power just to do something.

Actually (surprise) that's an intelligent statement. Yes it does require a large dedicated amp BUT not because it is poorly engineered (n = .66%). It requires a ton of power because the physics of what it is expected to do. Reproduce high SPL in the first ocatave. Acoustic power goes as Fs raised to the third power.

It also takes tons of power to launch an F18 off a carrier deck and that's why it uses twin GEAE F414 Turbo-fan engines with supplemental after-burners.

>>>>>This McCauley woofer was being featured in a pro folded horn, called Bassmaxx, to be blunt, it sucked!

Thanks for the tip (although I could do without the attitude).

For the home, the 6174 is suited for a 12-14 cubic foot vented enclosure tuned to 24-26Hz. Alignment is not trival, the acoustic mass of the port MUST be right and for the DIYer without the capability of measuring the impedance modulus, it's impossible.

In a large room with a dedicated 1kW amp, a single 6174 is capable of supplying enough LF content to supplement a pair of Klipschorns. Our small group here has recently completed one such system and the results were very impressive. I'm now in the process of building a second sytem for my own setup.

BTW, you mentioned it lacked "punch". In my listening experiences it's essentially silent on most recordings. When it comes in, it surprises you. The common response is "What's that!!" followed by hysterics.

You should really get out more.

[4313B]

Originally posted by John Warren
For the home, the 6174 is suited for a 12-14 cubic foot vented enclosure tuned to 24-26Hz.red = McCauley
grn = 2242H
13 cu ft tuned to 25 Hz
50 Hz 24 dB/octave LR LP

[4313B]

Twelve to fourteen cubic feet is a lot of real estate. I think I'd rather spend it on three four cubic foot volumes for 1500SUB drivers.

[John Warren]

Odd how the efficiency is "supposedly" so lousy yet, in your thermal limit analysis, the two "appear" to produce comparable SPLs at .8kW. Clearly the "disadvantages" of relatively low n are outweighed by the simple fact that the 6174 is operating within its linear piston range at the F-3 while the output of the JBL is
entirely vent transitioned.

Your analysis ignores completely cone displacement, desired SPL at a desired listening position, effects of EQ, power compression factor and distortion.

[4313B]

Yes. It is a very brief analysis. Taking more time to analyze the McCauley doesn't hold any interest for me but I welcome a more thorough analysis from other forum members. Like I stated before, if it were a "JBL killer" then JBL would be making it. Harman has enormous resources.

Frankly, for "typical" home use, I would take a pair of 1500SUB or W1500H transducers any day (I have a suspicion the 15-inch W1500H is going to be considerably more expensive than either the McCauley or the 2242H).

I am not sure why Niklas is interested in any 2242H replacements when he has sixteen 1500SUB transducers laying about. I suppose he hasn't had time to hook up any of the 1500SUB's and give them a go.

My comment on the lousy efficiency was based on their obvious typo. :p JBL has numerous typos as well. :(

[jblnut]

Maybe you have a lot larger room than I do, but for home use ONE Sub1500 is WAY more than enough provided you have 500 or so watts to drive it.

Two ?

that's just silly :-)


jblnut

[4313B]

Beginning in 1977 with the L212 I never could stand running single subs. :p The first order of business with that system was to order a second B212. JBL ended up selling them separately even after the L212 system was canned.

Don't get me wrong, I usually listen to one sub in a room before invariably adding in the second one. ;)

Here's a cute white paper (looks like it's been redone):

Subwoofers: Optimum Number and Locations (http://www.harman.com/wp/pdf/multsubs.pdf)

*****

BTW, a JBL Senior Engineer recently completed his four 1500AL-based subwoofers for his personal home use. They are augmenting Array Series trials.

[4313B]

Originally posted by jblnut
Maybe you have a lot larger room than I do, but for home use ONE Sub1500 is WAY more than enough provided you have 500 or so watts to drive it.

Two ?

that's just silly :-)


jblnut Oh! BTW, my two 1500SUB's are currently put away in the basement because they ARE too efficient for those 240Ti's I'm currently goofing around with. :p Even set at -10 dB they completely dominate the room. I can run one at -8 dB. If I seal them and cross them over around 50 Hz instead of 80 Hz they are quite decent! I'm playing around with two 121A's in 1.5 cubic foot boxes right now though. The smaller volume (B212 was 2.0 cubic feet) does help them a bit with excursion limited power handling. I'm planning to use the vented 1500SUB's with a pair of hybrid 4430's I'm working on.

[scott fitlin]

Originally posted by John Warren
>>>Scott F said:

>>>>Nothing above 60Hz.

The 6174 is a subwoofer (sub = below). It is designed to operate in the 16-32Hz octave range.

>>>>>Takes a ton of power, and needs a ton of power just to do something.

Actually (surprise) that's an intelligent statement. Yes it does require a large dedicated amp BUT not because it is poorly engineered (n = .66%). It requires a ton of power because the physics of what it is expected to do. Reproduce high SPL in the first ocatave. Acoustic power goes as Fs raised to the third power.

It also takes tons of power to launch an F18 off a carrier deck and that's why it uses twin GEAE F414 Turbo-fan engines with supplemental after-burners.

>>>>>This McCauley woofer was being featured in a pro folded horn, called Bassmaxx, to be blunt, it sucked!

Thanks for the tip (although I could do without the attitude).

For the home, the 6174 is suited for a 12-14 cubic foot vented enclosure tuned to 24-26Hz. Alignment is not trival, the acoustic mass of the port MUST be right and for the DIYer without the capability of measuring the impedance modulus, it's impossible.

In a large room with a dedicated 1kW amp, a single 6174 is capable of supplying enough LF content to supplement a pair of Klipschorns. Our small group here has recently completed one such system and the results were very impressive. I'm now in the process of building a second sytem for my own setup.

BTW, you mentioned it lacked "punch". In my listening experiences it's essentially silent on most recordings. When it comes in, it surprises you. The common response is "What's that!!" followed by hysterics.

You should really get out more. Let me rephrase myself! I do not like the 6174,s sound, and ive heard them many times in boxes designed for them! Even driven by a QSC Powerlight 6.0II they werent impressive, and others agreed. You like them, you use them, its a big world! Mostly this sub is for pro application, so I heard them at a club featuring them, and at a concert! I dont like them as much as JBL 2242,s in proper cabinets and an apropriate amp! JBL is audibly punchier with better definition!

One sound contractor is putting 2000w into each 6174 woofer, and still he cant get em to do what he expected!

Audio tastes are largely a matter of subjective opinion, and I am not a fan of the McCauley sound! I also own many McCauley 15,s and they werent my favorites either! I prefer JBL.

:)