PD-224 Dual 24" Subwoofer

I don’t have much experience in this field, but I want to learn a lot more about it

If you really want to learn, there are thousands of books and papers on-line which will give you some understanding of how loudspeakers work. I can suggest a few titles if you like. However, if you don’t want to get into mathematics, it might be useful to learn one of the free loudspeaker modelling programs. For sealed and reflex designs winisd is free and easy to use. It is ideal for comparing different drive units before buying. If you just want someone to advise you which is best, be prepared for conflicting opinions, or not if you want a specific review. Neither  Chatgpt nor Grok could find any user feedback. This is niche design for a niche drive unit, I wouldn’t expect may to be out there.

I have a question about sub-bass, that I hope you will be able to help me with. In my search for a perfect subwoofer

Just like there is no spoon, there is no perfect subwoofer. Cost, portability, ease of set up and, does the system have to pay for itself? All these factors, and more, can influence the choice for a given situation. It is not unusual to see designs where aesthetics are prioritised over acoustics or some change in layout is used to enable the designer to claim some degree of originality of design. Just because I, or anyone else, prioritises one aspect of the design above another, doesn’t mean that priority is correct for you.

This cabinet designed by Precision Devices utilizes two of the PD.24603BR, the 24-inch woofers….. ….Can anyone with experience in cabinet design please take a look at the plans and tell me if they have any doubts or red flags you notice that I should be aware of?

It is unlikely that Precision Devices would publish a design that didn’t work reasonably well. That said, it might be worth going over the plans. The drive units appear to fit in from the front, facing into the centre manifold. If the vertical brace is fixed in position, I can’t see how the drive units can be fit. The gap either side is about 180mm and the specs say that the drive unit is 250mm deep. There is no mention in the plans how this should be attached.

Any opinions/help you can offer me is greatly appreciated, thank you! :)

This drive unit is optimised for output rather than extended range. Its low frequency cut off is no lower than plenty of 12” -18” drive units, it just gets louder. Unless you intend to use them for reasonably large gigs, the output is wasted. Trade some of that raw output for smaller drivers that will go just as low, take up less room and cost far less. Alternatively look at drivers orientated for home theatre use which tend to be optimised for extended frequency response but get less loud overall (relative to 140+dB).

Thonmann has a price of £1175 per drive unit, so presumably something similar in Euros. Personally, for me. spending that much per drive unit is crazy, unless specified in a commercial project; especially when you consider the cost for the rest of the system, which you don’t mention. However, it is not my money, and you did say that price was not a consideration, so if this is a personal project do what makes you happy.

I read a few books already on the topic: The Sound Reinforcement Handbook by Gary Davis, Sound Systems: Design and Optimization by McCarthy and most recently Between The Lines by Michael Lawrence. Reading these gave me a (very) basic understanding of Soundsystem principles but I still want to learn so much more. if you have any other recommended reading material that would be fantastic! I feel like I still miss a lot of basic information to be able to fully understand and learn from this forum.

Dual 24s should be outstanding below 70 Hz....Go for it!!!!!

They get loud, but the bass extension is only down to 40Hz. For general purpose PA systems in large venues, this is a fine drive unit. If you don’t need the levels that this drive unit is capable of, it is not the best choice. There are plenty of smaller drive units that can go just a low, need smaller enclosures and cost less.

Given that the response graph with the plans states that it is predicted (it looks like a plot from hornresp) it could be that this design is still untried.

It would be worth modelling these in a 6th order bandpass as well