Lockdown Audio - A 12v 3way Small Rig Build

The subs will couple like that just as well as they will couple with the mouths together, I'd bet there will be no audible difference. If anything I'd suggest the opposite and keep it like that. Subs stacked higher should gain more directional control down lower due to the 'mirror' image reflected from the floor, giving you more SPL than a low/wide stack would. Though in this instance it probably won't make much difference!

Finally got to test it out all together and it was really good, had it on for about 8hrs of use, various genres of music and on max volume too and it pumps! Only needed it on around 1/2 - 2/3 volume though majority of the day was plenty. Battery used hardly anything too, i think ive got the gain settings pretty good now and the dsp is so good i love it!

Edited by Jack1991 - 05 May 2022 at 8:43pm

Yes it is good its easily removable. But yeh dont want to if its not necessary. You dont rekon the wadding is packing out the inside too much then and reducing the box tuning freqeuncy too much?

Edited by Jack1991 - 06 May 2022 at 12:20pm

I just skipped back a bunch but couldn’t see anywhere that you showed your WinISD plots / settings, or the cabinet dimensions for your mids. Can you share those?

You might find that the time of flight around the cabinet for your port’s output is arriving out of time with the same pass band from the front of the driver. If you have the cabinet dimensions, then you can calculate the time offset. A port’s output is anti phase to the diaphragm regardless - a polarity inversion and extra time delay is basically a principle of cardioid subwoofer setups for cancellation at the rear.

If you have that the wrong way round physically, the cancellation might be happening at the front instead. Hard to tell even stood at the rear of the mid box, because the directivity of the diaphragm output means you won’t hear the upper region anyway.

Also, did you account for port end correction in the model?

I can’t remember if it’s enabled in WinISD by default, but a port’s length generally needs to be adjusted from what the simple models say to achieve the desired tuning. The amount of end correction changes based on port dimensions and shape. Some software such as Tolvan Basta! has a check box to calculate a length correction factor, but even then there’s often some fudging needed based on measurements.

The reason I ask is that you may find the box is currently tuned too low. A friend did that recently on an 8” coaxial box - calculated the port to 67Hz but ended up under 50Hz which was so far in the roll off that it sounded thin. It’s easily done.

Adding lots of stuffing will make the box appear bigger acoustically at some frequencies too, so it might be making the problem worse.

Edited by Jack1991 - 06 May 2022 at 8:45pm