Yes, if you don't mind the EQ required to flatten LF response to 30 Hz.
At 30Hz, third harmonic distortion is over ~30% at 105dB/1meter in a sealed box at 25.9v (~100 watts).
Being only -10dB from the fundamental, the 90 Hz third harmonic would sound a bit louder than 30Hz if driven to 105 dB.
Could be, depending on what you listen to, and the volume you like.
Porting the system would keep the intermodulation distortion down, single tones really don't tell the story.
Art
I always get confused with db vs distortion. Does that include the +20 added to the plots? The levels are actually 20db lower than shown.
Rob 🙂
That EQ-ed version would be nice if you listen in a non-reflective environment, but in a typical domestic room, you may not need the 30Hz boost at all.
I can usually remember -20dB =10% distortion, but for the rest I check my chart 😉
Yes, appears the 3rd harmonic is +10dB over the fundamental at 30Hz, 10-20=-10dB, around 31.62% distortion.
The 2216ND's force factor (BL) has dropped in half from 18 to 9 (50%) at 10mm excursion while the stiffness of suspension (KMS) has almost doubled, so figuring ~7.5mm Xmax seems reasonable.
Or if you are in a room like Josh Ricci measured, you might need an additional +4dB on average at 30Hz over the half space simulation.
Better to figure no gain, and hope for better if you haven't already measured.
https://data-bass.com/articles/5cb5fb285389a80004c7e58a
If Superlian wanted more low frequency than midrange output, similar to the JBL/HARMAN living room target curve, the boost required could easily exceed +12dB.
Or not 😉
Yes it will.
As others have poined out the xmax is limited, you're EDS sheet has the corresponding klippel curves along with the cutout you pasted, for a good representation.
And the low tcr voice coil, dual coil, heatsinking frame with fins etc, and thereby excellent thermal stability, as shown in Erin's reviews (m2, 4367), gives it a advantage that does not pop out in TS specs.
IF you wanna go sealed and have the space, 2.5 way double 2216nd, gives you the reduction in excursion to play slightly loud 🙃
Added a snapshot of the same as Camplos. 4 drivers for a Stereo pair, in total reduces excursion quite a bit.
Attachments
Which makes it confident that this could play 81db avg very clean like, in a ported situation.
How many liter closed enclosure?
How much damping, 50%?
Is 81 dB more than a ordinary 2,5 way floorstanding speaker with 2x6,5 inch woofers in 30 liter enclosure?
I don't know the volume of the closed enclosure used for the 2216ND distortion test posted in post #1042.
Erin's test distortion test in post #1048 is of the M2 system.
The JBL M2 system uses a ported enclosure of ~180 liters (6.5 cubic feet) net.
It uses DSP to flatten it's on axis response to ~-3dB at 30Hz, Fb probably near that frequency.
The M2 system's polar response indicate the crossover frequency of 800Hz is a good choice for the waveguide using the D2430K high frequency driver and the 2216ND low frequency driver.
As it is a ported enclosure, probably no damping other than on inner wall surfaces.
A pair of sealed 2x6.5" inch woofers would only require ~1.6mm excursion to reach 81dB at 30Hz.
Might be possible to play at such a low level at one meter with under 1% THD.
By comparison, a single sealed 15" only requires ~0.6mm excursion to reach 81dB at 30Hz.
Art
THX
Then i need to find the optimal closed volume for a 30 Hz soffit version.
I will use JBL2451 with Truextent beryllium diaphragm. And biamp with active crossover off coarse.
I live in a appartement, therefore i cant play loud. But i really like the micro dynamics from the large format compression driver with beryllium in a horn. I also think that an 15 inch paper woofer gives a lifelike body in the lower midrange / upper bass. When i listen to classical work, even on low level, the double bass sounds much more realistic.
Here i will build a 4 meter wide bookcase with TV and hidden loudspeakers behind fabric with 10-15 degree toe-in. The typical listening distance will be a triangle c/c 3-3-3 meter. I will sometimes sit in the opposit side of the room 7,4 meter away but then with low listening volumes.
Then i need to find the optimal closed volume for a 30 Hz soffit version.
I will use JBL2451 with Truextent beryllium diaphragm. And biamp with active crossover off coarse.
I live in a appartement, therefore i cant play loud. But i really like the micro dynamics from the large format compression driver with beryllium in a horn. I also think that an 15 inch paper woofer gives a lifelike body in the lower midrange / upper bass. When i listen to classical work, even on low level, the double bass sounds much more realistic.
Here i will build a 4 meter wide bookcase with TV and hidden loudspeakers behind fabric with 10-15 degree toe-in. The typical listening distance will be a triangle c/c 3-3-3 meter. I will sometimes sit in the opposit side of the room 7,4 meter away but then with low listening volumes.
Last edited:
It's about 165 liters minus the woofer, HF driver/waveguide, ports and bracing. Calculated from the outer dimensions of the enclosure, with the indicated 25 mm wall thickness.
This is a good thread you can get some ideas from. I have my 2216's in a smaller ported cabinet tuned to 25Hz using a Q2 +6db boost @ 25Hz to flatten and extend the response.
Rob 🙂
https://www.audioheritage.org/vbull...2-DIY-Thread&highlight=passive+monitor+thread
Optimal to me means; Suits my needs. Everyone has ideas, ,my idea is to use the biggest driver in the biggest box tolerable. You are already settled on the m2 woofer. From there, just use the biggest box you feel tolerable. You simulate some of this stuff easily in winisd if you are up to it. The smaller the box the more power you will need to produce low end, the bigger the box, the more electrically efficient. If you stick around the size of an actually jbl m2 that has merit.