View Full Version : What would you do with a pair of JBL 1401ND woofers

08-21-2017, 03:56 PM
I just picked up a pair of NOS 1401ND woofers with crumbled foam surrounds, and I plan to refoam them. And then what???

These were used in the DMS-1 and later on some K2-xxxxx ? its sibling, the 1400ND with gold binding posts is also used in other K2 models.

I have no experience building any DIY speakers, so trying to DIY any of the K2 line would be out of the question. But these woofers rarely show up, so I think we have something special here....

What to do??... :-) Last pic is stock.

08-22-2017, 05:57 AM
Bascom H. King, former reviewer of Audio Magazine and now designer of PS Audio's BHK amplifiers, used to list his system in each review and he included custom built subwoofers with 1400ND subwoofers (not sure of the exact number, may have been 1401). Anyway, they might make nice subs if you don't want to make full range speakers.

08-22-2017, 02:45 PM
Some days I wonder if I should not have sold mine. There's something about greater surface area for bass that using woofers in pairs provides.

I had two pairs with original cones/surrounds. The mules I made for them followed the staggered tuning pattern of the M9500 and were tuned using porting information posted in these forums; I also drove them direct from good amps and applied EQ with White Instruments 4004's, not for bass extension, but for response tailoring. That gave me excellent bass into the high twenties.

They are very articulate, in JBL woofers 2nd only to 150xal family in my experience. Both series are underhung, by the way. While I had mine I experimented with singles using both the 2.8 box and the 4.2 box and thought neither worked for me. The single-woofer S7500 has been said to be targeted to the Japanese market where often smaller rooms and preferences in bass style would make it acceptable.

Somewhere in these forums there is a post from Greg Timbers about using the 1400nd as a subwoofer. He allows as how the parameters do not fall within the range usually seen as subwoofer meat, but an under-damped tuning in a largish cabinet could work. Excursion is limited by the small roll surround.

I had one pair and kept them on the shelf until I found a second, because I always think it is wise to be guided by JBL's use of its own woofers: DMS-1, M9500, S9500. That would suggest this woofer is best used in pairs. The M9500 crossover circuits are posted here somewhere. Attention to them would be necessary for good results.

A single might work in a small two- or three-way system, but then, why would you do that? The 252 (as in the LSR32/6332) has almost all of the technology and performance up to a certain spl, doesn't have a foam surround, is available new, or better yet, can be purchased used in a complete system and done. For VLF, you'd want a subwoofer either way.

08-22-2017, 08:57 PM
Hi Slowpat, (AND Svollmer, RE your post # 2)

I did write to Bascom H. king (care of Audio Magazine) after he published his review, in Janurary 1995, of a duo of Luxman amp and preamp, and where he mentioned having used for his listening tests B & W 801 Matrix series 3 s, "augmented in the range from 20 to 50 hz by a pair of experimental subwoofer systems, each using a JBL 1400 Nd driver in a 5 - cubic - foot ported enclosure."

I inquired about these 1400 Nd that I had never heard of, nor of a JBL experimental subwoofer using it. I asked Mr. King if we could learn more about the experimental subwoofer and the 1400 Nd driver. My letter and his reply were published in the April 1995 issue of Audio Magazine on pages 16 & 18 (which I still have).

First, Mr. King mentioned some confusion about the "experimental" subwoofer: "It in no way is a JBL experiment." But rather "What I meant was that it is an experimental woofer project of mine...". Then he mentioned "the 1400 Nd driver is not available for sale in the U. S., as it was used in two speaker systems, the K 2 and the M- 9500, exclusively for export to Japan." He added "I got the drivers through being a consultant to Infinity Systems, which is owned by Harman International, also parent company to JBL.

He had "heard from very acute listener friends that these were killer drivers." He also heard a system belonging to a JBL engineer using these drivers which had been modified from standard models. He was most impressed and got a pair of the drivers. He further adds "By positioning the subwoofers against the wall behind the 801s ..., I get a nice and extended response, down to about 25 hz, at the listening position." He then concludes "It is unfortunate that the 1400 Nd is not available as a separate item in the U. S.- B. H. K."

I hope this context info helps in deciding what to do with your own drivers.

Slowpat will need to run his driver's T/S parameters in speaker design software to see what kind of box suits his needs (5 cu. ft box as for 1400 Nd ?). Mr. King did not indicate the box tuning frequency he used.


08-22-2017, 09:44 PM
Thanks for the information speakerdave and Richard. That was pretty cool to get your correspondence printed in Audio Magazine. I will look into your suggestion on the speaker design software.