1400 Nd

[jim henderson]

Does anyone have the T/S parameters for the 1400 Nd?
Are they intrinsically shielded?

[10 Watt Street]

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]

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]

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]

very interesting.
How is the bass in the K2 S9500 ? Is it
amazingly detailed?

[jim henderson]

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]

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]

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]

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]

very interesting. do you mean that the 1400nd PRO i used in PA - systems?

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

[4313B]

"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]

What's the retail pricing on the 1400 Nd?

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

[4313B]

http://www.jblproservice.com/navigat...s%20lists.html

The MSRP price for the 1400ND is $715.56.

[10 Watt Street]

The 1400PRO is used in systems such as the 4892A and 4894A.

[jim henderson]

Regarding the shielding, I just picked up that pair that I referred to and placed them next to my TV without ill effect