Then some people say mini scoops act as reflex enclosures, which seems less likely to me although I can see how it might be seen that way.

When you put a constant cross sectional area port on a chamber with driver, that's a transmission line enclosure or 1/4 wavelength line as some like to call them. It resonates at well defined harmonic frequencies (open pope resonant modes) and the near field response measured at the port should show that. If you open up the mouth to turn it into a horn eventually the peaks go away and you get SPL gain over a bandwidth.

It doesn't look so bad. Box-Tuning seems around 37Hz but one can also see the membrane amplitude touching the 9.6mm around 32Hz. The way they get decent SPL probably has a lot to do with the large radiating area of the port, which is acting as a way to get the reverse wave out of the driver and make it usefully combine with the wave from the front. I don't really know a lot about the fashions and design of mini scoops, but from the few plans I have seen they seem to resemble a transmission line style design with a large cross sectional area port. Not sure if the ports tend to expand or stay a constant area, but if they do expand it doesn't seem like much. Certainly not like the quasi-exponential expansion of a full size scoop. The worrying thing can be seen from the cone displacement. The design unloads quite badly below 32Hz. You are going to need some good hi pass filtering. The maximum electric input also shows how the displacement and thermal effects how much input power you can apply before running into problems. Your limited to around 70 watts at 30Hz. The displacement plot also shows a peak at 60Hz, but at 9mm its well within the xmax of the driver and isn't likely to cause a problem. You can make a scoop less wide, keeping the horn path length and reducing cross sectional area. But then you cannot put as large a diameter driver in. And as they say if you want SPL, there is no replacement for displacement. Mouth area is probably going to be too small to ideally terminate horn length too so response is going to get lumpy.

The grunt people talk about from normal scoops is the rising output with frequency. The 60 to 80Hz output of a normal scoop can be very high and it's this that gives the impression of grunt and edge to the sound. A mini scoop plays flat as its a reflex and so while can be as loud as a normal scoop low down, doesn't have that 60 - 80Hz bite that gives the impression of raw SPL. It explains when people say, yeah the scoops at the dance were louder but the minis played heavy that night. It would still be nice to see a near field measurement of port output, that will leave no questions as to how the cabinet is acting. Or an impedance plot would do it. Well you know what Hoffman says about small cabinets. Which of sensitivity or low frequency response would you sacrifice some of to reduce cabinet size? No free lunch in physics. The question is does a mini's port act as a Helmholtz resonator (port) or a 1/4 length transmission line?Everything you say does make sense, I've never seen or heard one of these cabs for real and I haven't put the effort into measuring port lengths from any plans around. The impedance plot looks fine and will not give rise to any problems. It should be quite an easy load. You can also see the twin peaks, which is indicative of a reflex design. And yes, if I sim this design with horn simulation software, I still only get 2 impedance peaks.

First thing is wow, that is some very low vent air velocity. Peaking at 6 meters per second between 30 and 40Hz. This will never have any problems with vent noise. While Mini has shown off the 2025 Cooper in battery-electric guise, it has not yet revealed the combustion-powered models. While this is a little odd, we do know that ICE versions like this one pictured will look a little different than the EVs thanks to the presence of more traditional door handles, plastic fender flares, and clamshell hoods. All are sounding like a Mini is like only half as loud as a full. I just cant imagine that. It couldn't be that much. That's why i'm asking here about real world experiences in comparison of Minis with full Scoops or Hogs. The truth is that if you reverse engineer a mini scoop you can calculate it as a reflex design. You have a driver in a rear chamber that is ported to the outside. The only difference is that the port is tapered and larger than normal. As the port has a large cross sectional area it will need to be longer for a given tuning frequency, hence why the ports are between 1.2 and 1.5 meters in length. Most mini scoops are tuned between 35 to 40Hz and because of the large port (that can be equal to the drivers Sd), will have more output at the tuning frequency compared with much smaller ports with an identical tuning. If you sim a mini scoop as a rear loaded horn then you start to see what's going on. And that is that the horn acts as a port and the important thing is the rear chamber volume. If you sim with a 1.4 meter horn with a rear chamber volume of 30 litres you get an f3 of 58Hz. If you now make the rear chamber 200 litres all that changers is the f3, which now goes down to 29Hz. This is not what happens in a true horn, as it's the horn length that dedicates the cutoff. The impedance plot is also very revealing when comparing a mini scoop with normal scoop. The mini scoop only has 2 peaks, which is the same as a reflex design, the normal scoop adds a third higher peak around 100Hz that is associated with a rear loaded horn.Both group delay and phase look fine and the design is showing a max output of 128dB, although in reality this is 126dB as shown in the maximum acoustic power plot, which takes thermal and displacement constrictions into account. You can make the horn part of a scoop shorter. But now you are affecting low end cut off of the horn. This particular prototype appears to be a combustion-powered model and as such, the front grille is a little different than the three-door Mini Cooper EV that the British firm unveiled a few months ago. The most obvious difference is the presence of horizontal slats running the width of the grille. Hidden beneath the camouflage is the same updated rear end of the three-door model, complete with the same triangular LED taillights and the spoiler stretching out from the roof. Photo Credits: Baldauf for CarScoops Only thing what worries me is the displacement issue around the 30Hz. It' so serious that I'm concerned not to be able to play/hear some recent 30Hz club music.

If it as acting as a reflex the SPL from the port will peak at the resonant frequency and fall off either side. If it is a 1/4 length pipe you'll see lots of spiky resonant frequencies. Btw. please feel free to help me with sims of e.g. the MK3 or MK1 Version with the NXB1600 (already have this Driver), Thanks Ok, before i let you continue arguing about 60Hz punters (whatever that is) and not working BR Designs, i have to first and foremost say THANK YOU to Aman Gebru for taking time to lay the cards on the table about the physics and characteristics of the Mini Scoop Design. And sure also thanks to everybody else who help with a serious intention. I'm with you on all above but what makes me wonder is that the Mini is right in between of all that somehow. It has a short Horn (1/4) but the Mouth is to small so it acts more like a resonator. I just wonder because volume wise its not much smaller than a full scoop 120/60/76. The Mini goes with 90/60/75 so its "just" 30cm lower than the full and i just don’t want to accept that this should have such a great effect on SPL like everybody’s saying.

The only reason I say that is because I wonder if it is possible for the port to act with both characteristics of Helmholtz resonance and open pipe resonance simultaneously? Does it have to be strictly one or the other? If the reflex port was 1/4 60Hz in length would it not necessarily do both? Usually it is a non issues I suppose as ports are far shorter, and any pipe resonances are going to shifted up into a range that the driver assisted by the port is unlikely to be asked to play? You can shrink the rear chamber size, but that will increase driver damping and as many people will tell you some drivers just won't work like that because if intended to drive horns they are probably quite stiffly damped already via Qes. So you will need a driver with a less strong motor to compensate perhaps and that opens up other issues. The f3 is 41.3Hz and I think this would be a nice sounding speaker, but its not one for anyone who wants lots of output at 30Hz. Am I wasting energy using this one only between 35 and 70... SPL Plot tells me that it could be used till ~90? A mini scoops port gets larger, not smaller and if it were a transmission line would not have the required length to load it anywhere near low enough. The longest port paths found in mini scoops are in the 1.4 to 1.5 meter range, and if they acted like a transmission line would be tuned to around 60Hz. Many have ports that are around 1.2 meters long, which would be a tuning frequency of 72Hz if you believe they are a transmission line. Users of mini scoops are reporting hearing notes from their speakers lower than 60Hz, so something else is going on.