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jim henderson
08-19-2003, 01:56 PM
Does anyone have the T/S parameters for the 1400 Nd?
Are they intrinsically shielded?

10 Watt Street
08-19-2003, 02:20 PM
Supplied by Greg Timbers at JBL:

Fs - 24 Hz
Vas - 7.5 cubic feet
Qts - .22
Qes - ..23
Qms - 8.8
Re - 4.6 ohms

The 1400ND is maybe 300 W, primarily displacement limited. It shows
a No of 1.3%. Due to the extremely strange gap geometry, it has a much
larger difference between DCR and minimum impedance than typical
drivers, so that the actual measured response is below the predicted
sensitivity. Expect around 92 dB, midband for 2.83 V.

jim henderson
08-19-2003, 02:50 PM
Thanks!
My simulation software generates a non-monotonic response curve when I use a 5 cf enclosure. Is there a recommended enclosure volume?

10 Watt Street
08-19-2003, 03:10 PM
This is what Greg Timbers had to say when using the 1400ND as a subwoofer:

"The 1400ND has a foam surround. If the 1400 Pro is cloth, that would be
the only siginificant difference. The 1400ND can be used as a subwoofer,
but will have limited total output due to the small roll size. I have included
the major T/S parameters below. You will see that no combination of
enclosure volume and port tuning gives a traditional alignment suitable
for subwoofer use. However, if you use an oversize enclosure and a low
tuning, you can get a nice overdamped alignment which goes quite low in
frequency. The side effect is that the curve gently climbs from extreme LF
to the mmidrange. Since you are going to cut off the woofer in the 80 Hz
range, the real issue is a reduction in actual sensitivity between 30 Hz and
80 Hz. If you use multiple woofers, you won't have a problem for normal
applications. A pair of these would make suberb subwoofers for the
LSR28's. I would suggest around 3.5 cubic feet per woofer with a tuning
in the 30 - 32 Hz area. With the correct LP filter shape, you should have
very good woofers with solid response into the high 20's.

The alignment I suggested will burn 3 dB of level giving a flat subwoofer bandpass in the
89 - 90 dB area.

There aren't any data sheets as this transducer has only been used in
high end systems for Japan. If it were to have a retail cost it would be
around $1200 per woofer. I am using multiples of them at home and they
are awesome woofers when kept within their excursion range."

Take a look at how they were used in the M9500 and S9500.

Niklas Nord
08-20-2003, 12:15 AM
very interesting.
How is the bass in the K2 S9500 ? Is it
amazingly detailed?

jim henderson
08-20-2003, 09:27 AM
My current system consists of 2421/2344, 2123 and 2235 on the mains with a 2235-based subwoofer. I have the opportunity to pick up a pair of 1400Nd's for $550 and I wonder if replacing the 2235's on the mains with the 1400Nd's would be beneficial.

Another consideration is shielding as the main woofers will be near a picture tube. I could make a shield using mu-metal if needed, but would like to avoid that.

jim henderson
08-20-2003, 10:54 AM
From what I read, it appears that:

- The S7500/S9500 used 1400 Nd's
- The M9500 had better bass extension, due to larger cabs
- The 1400 Nd's have foam surrounds
- The 1400 Pro's have cloth surrounds

Here's my questions:

- Did the M9500 use 1400 Nd's or 1400 Pro's?
- What were the 1400 Pro's used in?
- What were the volumes of the M9500 cabs, the 3.5 cf that Greg Timbers recommends?

Niklas Nord
08-20-2003, 11:27 AM
in the DMS-1, there is a driver called 1401nd,
perhaps the same one.. or a 1400nd with cloth
is called 1401nd ?

10 Watt Street
08-20-2003, 12:46 PM
By the way, $550 is a very good price for 1400ND pair in good condition.

Some of the differences between the 1400ND and 1400PRO are covered in the excellent K2 profile at:
http://www.audioheritage.org/html/profiles/jbl/k2.htm

The M9500 uses 1400ND in a "Staggered Tuned" alignment. Enclosure Volumes:
78 liters (2.8 cu ft) 35 Hz tuning (upper LF)
115 liters (4.1 cu ft) 28 Hz tuning (lower LF)

The 1400PRO is used in many of the current high level pro systems.

Niklas Nord
08-20-2003, 12:54 PM
very interesting. do you mean that the 1400nd PRO i used in PA - systems?

how does the 1400nd compare with the 2234/35?

4313B
08-20-2003, 01:45 PM
"By the way, $550 is a very good price for 1400ND pair in good condition."

Actually that is a downright nutty price. Dealers can't even touch a pair for that! Harman employees can't even touch a pair for that!

The 1400ND currently appears to be in stock and available.

jim henderson
08-21-2003, 03:51 PM
What's the retail pricing on the 1400 Nd?

What's the URL for the price list(s) on the JBL Pro site?

4313B
08-21-2003, 05:04 PM
http://www.jblproservice.com/navigation/pdf_nav_parts%20lists.html

The MSRP price for the 1400ND is $715.56.

10 Watt Street
08-24-2003, 05:12 PM
The 1400PRO is used in systems such as the 4892A and 4894A.

jim henderson
08-27-2003, 07:38 PM
Regarding the shielding, I just picked up that pair that I referred to and placed them next to my TV without ill effect :)

4313B
08-29-2003, 06:46 AM
"I wonder if replacing the 2235's on the mains with the 1400Nd's would be beneficial."

For the mains that could be a good move. You will need to A/B them to see if you prefer the 1400Nd :) For subs use the LE14H-3 or the 1500AL if you're tired of the 2235H. :) 2242H's or 2245H's wouldn't be bad either ;)

"how does the 1400nd compare with the 2234/35?"

Overall it's a better transducer. If you want to use a 14" and need VLF use the LE14H-1 or LE14H-3. If you want to recreate the type of LF response popular in Japan use the 1400Nd. In simplest terms the 1400Nd is an LE14H-1 with a more powerful magnet (and a few other goodies which can be read about via the link 10 Watt Street posted). The more powerful magnet shifts the bandwidth up so the 1400Nd won't go as low as the LE14H-1 or LE14H-3. The extremely attractive thing about the LE14H-3 is that it has a rubber surround which doesn't require replacement due to rot. The LE14H-3 is used in the latest JBL 14" sub, the PS1400. Tip: If you build your own LE14H-3 sub, build the enclosure size as G.T. suggests for the 1400Nd; ~ 3.5 cubic feet and tune it around 28 - 30 Hz. I won't elaborate further since we are talking about current product. If you insist on using the 1400Nd as a subwoofer, use a high pass filter to protect it as it unloads below Fb or you run the risk of mechanical damage to the compliance, either that or simply operate it within it's excursion range which means don't beat it up with VLF. The LE14H-1, LE14H-3, and 1400Nd all have better LF resolution than the 2234 or 2235 at the expense of efficiency and mechanical power handling capability.

*****

Note - the PS1400 with the LE14H-3 also has a switchable subsonic high pass filter that can be used to help protect the transducer from excessive VLF excursion. I personally don't use any HP filter on my 14" subs but I don't drive them to their excursion limit either.

*****

"If you use multiple woofers, you won't have a problem for normal applications."

As G.T. states, this is a very good strategy. Mutual coupling will increase the output of a pair of closely spaced transducers wired in parallel and driven by a single amp by 6 dB in the VLF region. Scalability :)

"Since you are going to cut off the woofer in the 80 Hz range, the real issue is a reduction in actual sensitivity between 30 Hz and 80 Hz."

This harkens back to the halcyon days of the B212. :rotfl: Bandwidth limiting works for VLF transducers too ;) If you're modeling don't forget to add in your intended high pass filter and normalize the response taking note of the efficiency hit and the pleasant increase in VLF response. :) Again, multiples can be used to make up for the efficiency penalty. I've posted about this on every version of the forum but here it is again :)

jim henderson
09-03-2003, 01:41 PM
I just got my 1400NDs with fresh factory recones from Speaker City. They used LMS v3.62 to derive the T/S specs and got the following:

Fs - 26.9572 Hz
Vas - 376.5 liters = 13.29 cf
Qts - 0.2738
Qes - 0.2853
Qms - 6.75
Re - 6.7

Why are these numbers so different from the specs described above? Do the drivers need to be broken in before meaningful measurements can be taken?

4313B
09-03-2003, 03:18 PM
"Why are these numbers so different from the specs described above?"

Well, my guess without running those numbers is that JBL changed the cone assembly back to the LE14H-1/LE14H-3. What kind of surround did you end up with? Foam? Rubber? Thick? Thin? Vas looks a bit high as does the Qms for an LE14H-1, Qts, Qes and Fs look about right...

"Do the drivers need to be broken in before meaningful measurements can be taken?"

Well yeah! I'm sure the reconer did that before taking the measurements... are these all the measurements they gave you?

jim henderson
09-03-2003, 04:38 PM
The surround appears to be standard JBL foam. Here's the spec sheet:

4313B
09-03-2003, 05:50 PM
Well Jim, I'm thinking that driver hasn't been broken in. Can you call them and ask them if they broke it in before running the parameters? What do the other driver's parameters look like?

jim henderson
09-06-2003, 02:30 PM
Speaker City replied with this:

"CR81400ND was the part number on the kit, and we tested but did not "burn" in the component when testing. Usually, the Fs will drop a little after break in, but not more than 10%."

4313B
09-06-2003, 03:00 PM
That's fine. It is true that some transducers don't vary by more than 10% before and after break-in. I have noticed the newer JBL transducers don't vary nearly as much. Many of the older transducers vary substantially more than 10% before and after break-in.

boputnam
09-06-2003, 06:21 PM
Originally posted by Giskard
Many of the older transducers vary substantially more than 10% before and after break-in. As a matter of fact, this LE14A I'm working-in, has improved remarkably over the past 4-hrs. The new surround was quite dense, and stiff, and was not very compliant. Notable improvement, with time.

4313B
09-06-2003, 06:29 PM
Interesting. I've recently tested another batch of 2245H's and 2242H's. The 2245H's varied substantially, a drop of ~ 5 Hz after break-in (Same with a recent pair of LE14H's). The 2242H's are like granite. They didn't move hardly at all. The Fs dropped like half a Hertz after beating them with a big stick for 36 hours.

One thing is for sure, these 2242H's are built for one thing, and that's causing serious, irrepairable, unrecoverable brain damage in the LF and VLF.

boputnam
09-06-2003, 07:14 PM
What did you say...?

;)

Ian Mackenzie
09-06-2003, 07:26 PM
Okay,

Lets not panic, it probably compensate out some where else as far as your end tunin go's.

Ian

4313B
09-06-2003, 07:33 PM
Huh? Talk louder please...

;)

boputnam
09-06-2003, 07:33 PM
:spchless:

Robh3606
09-06-2003, 07:49 PM
Hey Bo

You just refoam them?? Fun Ha! That surround is like a brick! Stiff as hell. Same with me took a little while to run them in. It is almost twice as thick as the one for the 12"s look's different too. Let me know what you think. How big a box??

Rob :)

jim henderson
09-15-2003, 07:08 PM
I measured these myself using this method http://sound.westhost.com/tsp.htm and got:

Fs: 23.5 Hz
Vas: 206 liters = 7.27 cubic feet
Qts: .166
Qes: .170
Qms: 7.051
Re: 4.8 ohms

I have no idea what Speaker City did :confused:

Earl K
12-02-2004, 01:08 PM
Hi Jim Henderson

Whatever happened with this project ?

Did you build up some 3.5 cu' subs, as per G.T.s directions to 10 Watt Street. ?

- just curious / also, I thought Guido might like to review this thread . :yes: :hyp: :yes:


,> Earl K :thmbsup:

jim henderson
12-02-2004, 03:26 PM
The project has morphed somewhat. I'm now running a pair of Sub 1500's for the low end, and my main speakers will be 2-ways with 1400ND's on the bottom and TAD 4001's on top. The horns are TBD but the Westlakes are the front runners.

I built 4.1 cf ported enclosures (a'la M9500's) for the 1400ND's and they work fine but I don't need the LF entension with the Sub 1500's in the system. So I will probably go with Greg's advice and build cabs with "around 3.5 cubic feet per woofer with a tuning in the 30 - 32 Hz area".

I wonder if sealed cabs would be a viable option. The advantage would be less distortion. The disadvantage would be no LF extension. Again, the Sub 1500's could pick up where a sealed 1400ND leaves off.
As an aside, the reconed 1400ND's I got from Speaker City have come apart at the spiders a'la the Sub 1500's. Speaker City sent me some glue to repair them but that didn't hold. Of course we now know from the Sub 1500 thread which glues work properly.

Earl K
12-02-2004, 03:42 PM
Hi Jim

Thanks for your quick reply. Sorry to hear about the glue problem on your recones - but good to know that enough attention was previously paid to it in within the forum - so that a solution was at the ready. :thmbsup:

If it was me, I'd build some smallish ( 2.8 cu' ?? ) test boxes ( a la the top portion of the M9500 - tuned to maybe 35hz ( or higher ) . You can always use your 4.1 cu' boxes for this - if you reduce/occupy some of the volume with sand bags ( etc. ). Sealed boxes , would also interest me - I'd try both variants to see what gives the best results.

regards <. Earl K :rockon1:


ohhh - I forgot to ask ; Did you ever "gap-out" those 1400nd(s) in those oversize ( 4.1 cu' ) boxes ?

Didier
02-15-2018, 01:53 AM
Hi,
I wonder how the parameter would change ( Fs? ) if replacing the cloth surround by foam on a 1400Pro.
Someone did it in the past?
Kind regards,
Didier

sebackman
02-15-2018, 08:51 AM
Hi Didier,

The cones are very different, so who knows what kind of "bastard" you would get.

Why not recone them if you have the recones or find a nice pair of 1400Nd/LE1400H/LE14H-3 on the market and leave the PRO1400's as is. A Franken-woofer may work but it is not likely that it will exceed a fresh "original".

My 25 cents...

Kind regards
//Rob

grumpy
02-15-2018, 01:04 PM
In my head I hear the incomparable Teri Garr saying "Frankenwoofer" every time someone uses that portmanteau.