You are right, I was also thinking the same but I decided to make some research to find the answer better explained.
So, looks like all Back Load Horn has the same issue, I mean, the combined wave from the driver's front + back will be out of phase and will create cancellations (dips). Probably FLH with vented rear chamber will have the same issue. once sealed chamber will break super planar proposal maybe the only way to improve the frequency response would be to adopt some improvements technique used at transmission lines like driver off-set (already included), the "stub", filling and tapering the path, at the end Super Planar could a TL with front resonator?
MMJ, did you tried any of those improvements yet?
Attachment #2 there are 2 sketches considering the "stub".
An Improved Transmission Line Alignment.
Attachments
You should ask MMJ to create a specific thread for the super planar top. I don't mind
It is fine guys, we can discuss Super Planar tops here, we have done it many times already
..... No problem at all .....
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Sansui ,
We have already explored stuffed offset-driver stubs (and tuned stuffed stubs) to the extreme years ago in the Constricted Transflex (as in ML-Transflex and Karlflex) discussion .................... After that adventure I decided i wanted to find a higher performance solution , and that is what brings us to this current discussion about combining compound loading with quarterwave resonance, compound horns and such (Super Planar and Paraflex designs)...
Sansui , please go back and look at the some of the very first posts in this discussion ....
The original purpose for making this a compound loaded system (adding the high-tuned resonator) was to overcome the issues with cancellation seen just above the Fb*3 harmonic in the midbass range which yes is a problem typically suffered by BLH/RLH cabinets , QWP (non-offset "TL") cabinets , Tapped Horns and Classic Transflex cabinets ......... Our high tuned resonator (what i am calling a front chamber here , or "rear vented" in Hornresp) is tuned strategically to fill in the response hole just above Fb*3 harmonic which actually shifts up or down in relation to the fundamental tuning based upon how much expansion or taper there is in the path ......
We discovered that this compound loading strategy had the additional benefit of improved efficiency and increased output!
It is true that our high-tuned resonator (or front chamber or "rear vented" chamber) does not address the system's harmonic energy well above it's tuning, so there will be some dips and peaks in the midrange however these things can be overstated by Hornresp and by the time we reach 870hz the output from the front chamber and front of driver's cone should be easily outrunning anything coming out of the main path (main path meaning the longer path , the LF tuned path) ............. So in reality it is possible that there may not be any problem at all around 870hz (or it is not as extreme as shown in Hornresp and not noticeable to the listener) , we really can't be sure until the cabinet is built and measured , although i can say that there was not a problem in that range with the 2X12 Super Planar cabinet ... .. .....
On this 1x12 i would expect the dip at 455hz and the peak at 260hz to probably show up in the real-world measured response but not necessarily as prominent or volatile as shown in the software model .. .
People who have built the 2x12 Super Planar tops report that they love the sound of them .... Rich, bold, punchy, and dynamic midbass with midrange that extends high enough to meet most people's needs ..
Sansui, if you would like to experiment with a little bit of additional driver offset and some stuffing in the offset-stub i think that is great but i would suggest not taking it too far (30% offset is too far in this model, try no more than 20% offset)....You do this by adjusting L12 in the Loudspeaker Wizard.....There is also an option in the Wizard for stuffing/filling.............NOTE: Too much offset and a lot of stuffing will result in performance losses for the sake of fixing a problem that may not exist in reality.....
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Correct
Although to address a problem at 870hz the stub would only need to be a quarter wavelength at 870hz in theory .... Not very long Correct. Hornresp models the chamber as a cylindrical tube with a circular cross-sectional area of Ap and an axial length of Lpt.
Hi MMJ,
I made some simulations yesterday taking into account what you said and I can confirm almost all you said and what you shared is basically the optimized result. The frequency response in all cases present the peaks and dips due to the phenomena linked to the cab design (front and back wave phase aligment). The doubt is if the real measurement will present the same response regarding the simulation and in this case I will take a safe place and assume that the dip will exist in real life based on the others cab design as "super scooper". The amount of output SPL Super Planar is able to deliver impressed me but there are some issues that I may should wait for some simualtions vs measurements comparison to make a conclusion.
In the mean time I also discovered that the BR 10" cab I built has a wrong volume, so it can be optimizes to gain +5dB arround 120Hz, more or less the same problem you saw at super planar 10", at BR it can be fixex reducing the internal volume from 20L to 10L, maybe at Super Planar I should increase the compression ratio in that case.
Note: I start to learn deeper after I built the 10", till that time I was just coping existant designs.
I made some simulations yesterday taking into account what you said and I can confirm almost all you said and what you shared is basically the optimized result. The frequency response in all cases present the peaks and dips due to the phenomena linked to the cab design (front and back wave phase aligment). The doubt is if the real measurement will present the same response regarding the simulation and in this case I will take a safe place and assume that the dip will exist in real life based on the others cab design as "super scooper". The amount of output SPL Super Planar is able to deliver impressed me but there are some issues that I may should wait for some simualtions vs measurements comparison to make a conclusion.
In the mean time I also discovered that the BR 10" cab I built has a wrong volume, so it can be optimizes to gain +5dB arround 120Hz, more or less the same problem you saw at super planar 10", at BR it can be fixex reducing the internal volume from 20L to 10L, maybe at Super Planar I should increase the compression ratio in that case.
Note: I start to learn deeper after I built the 10", till that time I was just coping existant designs.
The design is very impressive! I wish I had the space in my truck to test his design.
Here we go Mr Sansui . . . A single Snake ESX10 in a Super Planar top
.................. ID=42.00
Ang=2.0 x Pi
Eg=40.00
Rg=0.00
Fta=0.00
S1=300.00
S2=300.00
Con=20.00
F12=0.00
S2=300.00
S3=300.00
Con=26.10
F23=0.00
S3=300.00
S4=300.00
Con=20.10
F34=0.00
S4=300.00
S5=300.00
Con=24.30
F45=0.00
Sd=314.00
Bl=17.63
Cms=1.99E-04
Rms=1.79
Mmd=25.16
Le=0.28
Re=5.00
OD=1
Vrc=0.80
Lrc=0.70
Ap=900.00
Lpt=30.00
Vtc=0.00
Atc=0.00
Pmax=100
Xmax=5.0
Path=0.0
Mass=0.00
Fr1=0.00
Fr2=0.00
Fr3=0.00
Fr4=0.00
Tal1=100
Tal2=100
Tal3=100
Tal4=100
Comment=Snake ESX310 10" 85hz Super Planar 55L for LordSansui MMJ
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FILTER
0 0.01 0.0 -1 0 0.01 0.0 -1 0 0.01 0.0 -1
0 0.01 0.0 -1 0 0.01 0.0 -1 0 0.01 0.0 -1
100 25 0 0
40.50.50.5
0.50.50.50.5
SSSS
1111
1111
2222
1111
111
000
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Two of these on a toed-in crossfiring baffle would make a fantastic 2x10 Super Planar top
Here we go Mr Sansui . . . A single Snake ESX10 in a Super Planar top
Thanks a lot MMJ, but check the comparison below vs a BR.
Attachments
Mr Sansui ,
For a fair comparison lets match the fundamental tunings (Fb) more closely ..
Here it is tuned to 110hz with that same ESX310 driver .. .. It is now about 40 liters net ..... You will notice that both paths are shorter now (main path and front chamber .... They must scale down together..)
ID=42.00
Ang=2.0 x Pi
Eg=2.83
Rg=0.00
Fta=0.00
S1=300.00
S2=300.00
Con=15.10
F12=0.00
S2=300.00
S3=300.00
Con=17.60
F23=0.00
S3=300.00
S4=300.00
Con=13.30
F34=0.00
S4=300.00
S5=300.00
Con=22.60
F45=0.00
Sd=314.00
Bl=17.63
Cms=1.99E-04
Rms=1.79
Mmd=25.16
Le=0.28
Re=5.00
OD=1
Vrc=0.80
Lrc=0.70
Ap=900.00
Lpt=20.00
Vtc=0.00
Atc=0.00
Pmax=100
Xmax=5.0
Path=0.0
Mass=0.00
Fr1=0.00
Fr2=0.00
Fr3=0.00
Fr4=0.00
Tal1=100
Tal2=100
Tal3=100
Tal4=100
Comment=Snake ESX310 10" 110hz Super Planar 40L for LordSansui MMJ
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FILTER
0 0.01 0.0 -1 0 0.01 0.0 -1 0 0.01 0.0 -1
0 0.01 0.0 -1 0 0.01 0.0 -1 0 0.01 0.0 -1
100 25 0 0
40.50.50.5
0.50.50.50.5
SSSS
1111
1111
2222
1111
111
000
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You are convincing me
104dB/1W/1m from 115Hz to 400Hz from a single 10"driver with a 40L cab is realy a very seductive proposal.
I will play around to see if it's possible to flat it a little more.
Accepting help
Right ...tempting
.. . This is what i ended up with .. Very similar .. .. ..... Halfspace .... Fundamental tunings are matched here ... 
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In trying to get the SP flat it also looks like you have given up much of the performance advantage .... Partially due to the fact that your 25 liter Super Planar is tuned lower .....Notice how the response "knee" on the reflex and large SP are located higher up than the 25 liter SP ..... Your reflex cabinet appears to be tuned highest of all .. .......
Match the tunings for fair comparisons....
The extra gain and headroom in the lower range is very valuable, it is gold, not worth sacrificing if these are to be used in an application that demands high SPL or very high effiiciency . .....
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