1400Nd Vs 1200Fe (2- way with 1.5 horn)

[sebackman]

Hi Didier,

I had mine in a +40m2 room and there was no problem to play loud with enoughbass.
But as always it's only your ears (and maybe yourfamily :-) ) that can decide what is enough.....

In my work-shop (2x48m2) I play a pair of JBL F12 clones on each floorwith a single 2226 under each box and that is loud beyond what is comfortablewhen the volume is turned up.
I say start with a single 1400nd on each side, you won’tbe disappointed. They are really fabulous woofers.

Kind regards
//Rob

[Didier]

Now Dieter it's clear! . Rob, I think I'll fit the reconne in the 1400Pros
Interresting to see that the curve seems better with 80L than more . I thought 120L was better with this speaker...
From elsewhere, close to the 1200Fe in 60L.
Didier

[sebackman]

Hi Didier,

I think the curve may extend deeper with a larger cavity hence the larger cavity when JBL made the K2 speakers. This was probably the best way back then as DSP was not readily available and amps were expensive compared to today.

Today we can easily correct the earlier fall off in the smaller cabinet as long as the cone motion and power capacity is not limiting. For me it was not.

The important thing if using smaller cavity is that the curve is smooth and falls off in at even pace. That makes it simple to correct with a DSP and the LE1400H delivered just that and I have no doubt your 1400nd will do the same, if not better.

Dependent on placing you will also get some bass support from corner and/and potential floor location. My curve is near field so none of that is visible. My ports were rear firing and that also helped in my application with some support from the corner.

Kind regards and good luck
//Rob

[RMC]

Hi Didier,

The T/S I used for modeling are the same that Dieter has posted. Don't forget in Win ISD to change the default QL 10 to a more appropriate QL 7, and don't choose the default BB4/SBB4 alignments but rather the QB 3 alignment in the menu. That should cure the weird looking response curve.

Richard

[RMC]

Hi Didier,

An 80 L. box with 30 hz tuning isn't a good idea in my view even if you compensate with DSP (i.e. equalization) because it requires more power which leads to more distortion caused by increased cone travel...

Winspeakers response for such a box: a decrease in level starting around 200hz, -1.5db@100hz, -3db@50hz, -6db@32-33hz. This is quite similar to earlier modelings I did for you and my same comments apply here.

Since computer modeling with T/S already assumes one boundary speaker placement (e.g. floor) you would need at least one more boundary (e.g. floor and back wall) or maybe corner placement (three boundaries) to increase the low-end at an acceptable level compared to the higher frequencies reproduced by the 1400nd driver.

A steep high-pass filter is usually required as E-V doest it with their "step-down mode EQ" and there are other conditions like, if my memory is correct, tuning half an octave below "normal", not just any frequency below... You should read more on this issue.

The speaker placement option requires no added power or DSP (i.e. its a FREE boost from the room!). If you were to go Rob's way then I would suggest you take the room gain option first rather than lower tuning.

Remember, as fabulous as it may be, the 1400nd is NOT a 2245H subwoofer...

Finally, the "not bad" in my previous post did not mean "so and so" but rather still quite good or acceptable.

Regards,

Richard

[speakerdave]

. . . . Remember, as fabulous as it may be, the 1400nd is NOT a 2245H subwoofer . . . .

+1

GT has commented in these forums that the limiting factor is the small roll surround, so alignments calling for VLF EQ would be counter indicated, I should think, especially if reaching below Fb.

[Didier]

OK, I understand well, it's not easy with a single 1400Nd to get somme good LF response naturally. Moreover, I need a good behaviour until ~750Hz and It's maybe a bit high for a 14"
Maybe 1400Nd is not the best choice , that's why I spoke about the 1200Fe (that I don't have). GT used it in his DIY system until 750Hz if I remember well but with some subs...
Do you consider this kind of speaker more apropriate to my application?
Thanks again for you help
Didier

[speakerdave]

In my opinion:

Realistically speaking you have to look at the way JBL drivers are used by JBL. You might be starting with concepts that may be incompatible--a box of a certain size, two different possible drivers, and a certain requirement for bass extension. On the face of it, your requirements contravene the entire history of those drivers and JBL's use of them. I suppose one of us should have said that up front. The answers to your questions are interfering with your concepts. We have been implicitly trying to change your mind about something.

Also, what is your choice of horn? How does that look with a 60 liter box?

Generally speaking, low bass in a small box comes at the cost of efficiency and along with it compatibility to horn treble.

You ask about the 1200fe in 60 liters; I suggest you study the 4429. What did you find out?

Given that you actually have in your possession the makings of some 1400nd's, AND 1200fe's won't do what you want anyway, the only logical option seems a change of mind about either bass extension or box size, it looks like to me, sorry to say.

[RMC]

Hi Didier,

RE:"... it's not easy with a single 1400Nd to get somme good LF response naturally." I totally disagree with that statement, unless your requirements are too high for the laws of physics.

Among the modelings I did for you are boxes that I would be quite happy to have since none of mine go deeper than 38 hz (F3 of 12" 2214H cabinet). Your whishes have to be compatible with physics though.

In this regard, I suggest you read the following, if you can find them on the Net, to understand how bass works:

Ray Newman, A systematic approach to Loudspeaker Design, Stereo Review, August 1981, P. 58 (Ray was Chief Loudspeaker Engineer at Electro-voice, the equivalent or so of GT at JBL, and D. B. Keele's boss when he started his career at E-V in the early seventies. The System Interrelationship Equation (SIRE) is of paramount importance;

John Hoge, Confessions of a Loudspeaker Engineer, Audio, August 1978, P. 47

Among many others I have. I can't reproduce these here since its Copyrighted material. Then you'll better understand how bass can be achieved and what is a reasonable expectation and not in terms of low-end. Regards,

Richard

[Ian Mackenzie]

Hello everybody,
In order to build a second system, I'd like your point of view please
I already have, some 1400Pro and a 1400Nd reconne kit, 2450SL, H9800 Behringer clones and nice Woody's Arai 1.5
My first idea was to build some enclosure with the same volume as the M9500: 115 liters (4.1 cu ft) 28 Hz tuning (lower LF), but if it's possible to get the same (or better) result in a smaller box: - it's better for my living room
Then i think to the 1200Fe even if it's difficult to find... (but i have time )
According to you, which of these two speaker is better until more or less 700Hz -750Hz?
Thank you,

Didier

If your overall objective is a smallish enclosure then perhaps consider the LE14H-3 as a single driver or the 2216nd-1 which is obtainable

The LE14H-3 was used in the model 4600 and the 2216nd-1 in the 4367

[Didier]

Hi,
As speakerdave says, I have in my possession the makings of some 1400nd's, AND 1200fe's won't do what I want anyway.
And I want a single woofer system...
So, if don't want any regret after, I will built a 120L box (a la M9500), and if necessary use the room and a bit of Eq..
The horn I plan to use are Woody's Arai 1.5 (Size: 44.7 x 14.5 x 27.4) and the drivers 2450SL.

Hi Ian, the minimum frequency will be 700-750Hz.
According to the information I found, the LE14H-3 are probably better than the 1400 for the low frequency but not for the midrange...
Didier

[speakerdave]

Pretty horns.

[RMC]

Hi Didier,

A single 1400 ND in a 120 L. box tuned at 37-38 hz looks like a nice compromise with an F3 @ 36 or 37 hz and a small drop of 1 db centered at 75 hz. I don't think you'll need EQ to be satisfied but if need be try first placement at a second boundary (floor and back wall junction), since this room gain doesn't require more power contrary to EQ. As with any vented box a steep high-pass filter is always a good idea below tuning frequency. I would put one at 35 hz to moderate your tendency to extract more VLF than what the driver can keep up with... Regards,

Richard

[sebackman]

Dear all,

I do agree with both RMC and speakerdave and there is nothing in their posts above that contradicts what I wrote and have experienced actually building and measuring something similar.

Placing in the corner, rear firing ports (if corner placed) and placing near the floor will give you some real life gain in the bass region as stated above.

If you do the bigger cabinet you will probably be fine with little or no compensation as stated by RMC. I totally agree that this would be the preferred startingpoint when thinking about size and placement.

However, given that you can achieve some room gain as per above I do disagree that the smaller box would post a problem in respect of using EQ to compensate for the quicker fall-off in the smaller box.

No doubt the foam rolls are smaller than on other “heavy duty” woofers but in my experience building the “Compact monitor” that did not impose a limitation.There was completely neglectable distortion for HiFi use due to additional cone movement with EQ.

If you do need LFE or play very loud very deep down it is not enough with one 14” woofer per side regardless of model. LE14H-3 or 4 may be better but is no cure if that is what you need. As said above by others you need to find the acceptable compromise or look at other/more drivers.

120L is better if you have the acreage to place them. 80-90 (I think mine were 86L) will be just fine in in a normal listening room <50m2 for HiFi use. For PA no. For film (LFE) no. For loud 32 feet organ pipe listening no. -But do you do that often??

Not disagreeing with anything said above but merely saying that if you do decide to sacrifice some cabinet volume on the WAF altar that is not terrible and with some EQ the result will be completely indistinguishable from the bigger cabinet for the vast majority of your listening time.

I do encourage to build a test box before you decide and take the cost/time for real cabinets. At least for me, simulations did not tell the entire story. In my case, reality with the 1400H’s turned out significantly better than any of the simulations did. And I could also port them deeper without the curve looking silly.

Also agree with RMC on the high pass filter albeit I had a steep filter set at 24Hz in the DSP. Especially important if you play Vinyl's.

And by the way, at least the LE1400H (same cone as 1400Nd, different motor) is no problem at all up to 900-1000Hz to meet a M2 waveguide (or other).Measurements show pretty seamless transition and several pairs of ears confirm that it worked real well in the active 2-way DSP setup I built with M2 horns. J

-Or you can sell the 1400Nd’s to me cheap as they are no good and buy a bunch of 2216Nd’s with some 2245's below.…..

Kindregards
//Rob

[Ian Mackenzie]

Hi Rob

I think you summed it up well.

It might pay for the user to build a test box with an internal removable shelf so a small versus larger box can be trialed in situ so the user can discover himself what works best in reality.

In own experience building a test box and listening is the acid test. It will either be good or crap.

Distortion of lower tunings and smaller boxes
I did look at the DB Keele B6 formula and the driver can be step down to an f3 of 32 hertz if desired.
Keeles caveat is if you must play synthesiser or pipe organ music then that option will produce more real output with low distortion than either QB3 or a close box. But there may be a reduction of 3 dB or so real acoustic output in the pass band above the tuning frequency.

The linchpin here is cubic displacement and Xmax. Displacement (multiple or larger drivers) will nearly always win over Xmax for normal music reproduction

Making the box significantly smaller than optimum and attempting to tune for a best case scenario with a higher tuning seems counterintuitive to the whole purpose of selection this particular woofer.