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This isn’t intended to be critical of any approach that is contrary to my opinion. The subject has come up in this and other forums. It’s a subject we have experience in and audio is something I’m passionate about. Questions and other opinions are welcome.
When you add equal power with each additional sub then obviously two subs will be louder than one and three will be louder than two and so on. There will be a list of ‘howevers’ however.
Subwoofers have considerable mass so just adding more subs with more surface area won’t necessarily net more output without adding more power too.
But what you might find interesting is that you’ll rarely achieve the efficiency with multiple subs as you will with a single sub. Although multiples will put out more it’s the first subwoofer that is likely to be the most productive.
It’s a little different than in a hatchback coupe or SUV where multiple subs are symmetrically loaded. Everything is pretty much equal in a vehicle. The subs share the same baffle and compound load. If you double the drivers and power you’re bound to get double (+ 3 dB) the results.
But a boat is decidedly different. In a boat the first subwoofer usually is in the best available locations and is optimumly loaded. The second sub location is often a compromise. Usually the third subwoofer is even a greater compromise. In a boat, with each added sub, we have changes in enclosure size or type or loading in respect to the surrounding boundaries. We just wouldn’t see many scenarios in a boat with two or more big woofers symmetrically loaded.
The first of many things to note in understanding why is that amplitude and phase are interdependent. If you change the amplitude or frequency response then you have simultaneously altered the phase response and vice versa.
A woofer, once loaded into an enclosure, has a new amplitude response and corresponding phase response. Whether the enclosure is large, small, sealed or ported, each will have unique characteristics pertaining to frequency response and phase response. And, we have to take this one step further. The woofer’s final amplitude and phase response is the summation of the woofer, its enclosure and how it is immediately loaded. Loading would describe the surrounding boundaries including lockers, consoles, cavities, decks, coaming, etc. Whether direct-radiating, down-loaded, vented out of a storage compartment or in combination, these factors become an extension of the raw driver just like its enclosure.
So, now we have assymmetically-loaded multiple subwoofers with random amplitude and phase responses. Dissimilar speakers do not sum as efficiently as identical speakers. There’s more information on this if needed. You now have several woofers, that are different based on their varying enclosures and loading, that sum or don’t sum or may even subtract to a lesser degree depending on your listening position as you move around.
Will multiple subs in different locations play louder? Sure. Even a clumsy design will play louder. How is sound quality? To a trained ear it sounds blurred with less tonal construction.
How about efficiency? All those subs, enclosures and amplifiers will not be as efficient or cost-effective as the first subwoofer.
It is hard to beat the production of a simple approach with a single sub of the highest quality, properly powered, in the optimum enclosure that takes advantage of the most ideal location including the surrounding boundaries.
Its also a good idea to optimize the design efficiency in consideration of our limited charging systems.
That being said, for anyone who wants us to add a ton of subs and amps to their boat, I’m totally on board!
David
Earmark Marine
When you add equal power with each additional sub then obviously two subs will be louder than one and three will be louder than two and so on. There will be a list of ‘howevers’ however.
Subwoofers have considerable mass so just adding more subs with more surface area won’t necessarily net more output without adding more power too.
But what you might find interesting is that you’ll rarely achieve the efficiency with multiple subs as you will with a single sub. Although multiples will put out more it’s the first subwoofer that is likely to be the most productive.
It’s a little different than in a hatchback coupe or SUV where multiple subs are symmetrically loaded. Everything is pretty much equal in a vehicle. The subs share the same baffle and compound load. If you double the drivers and power you’re bound to get double (+ 3 dB) the results.
But a boat is decidedly different. In a boat the first subwoofer usually is in the best available locations and is optimumly loaded. The second sub location is often a compromise. Usually the third subwoofer is even a greater compromise. In a boat, with each added sub, we have changes in enclosure size or type or loading in respect to the surrounding boundaries. We just wouldn’t see many scenarios in a boat with two or more big woofers symmetrically loaded.
The first of many things to note in understanding why is that amplitude and phase are interdependent. If you change the amplitude or frequency response then you have simultaneously altered the phase response and vice versa.
A woofer, once loaded into an enclosure, has a new amplitude response and corresponding phase response. Whether the enclosure is large, small, sealed or ported, each will have unique characteristics pertaining to frequency response and phase response. And, we have to take this one step further. The woofer’s final amplitude and phase response is the summation of the woofer, its enclosure and how it is immediately loaded. Loading would describe the surrounding boundaries including lockers, consoles, cavities, decks, coaming, etc. Whether direct-radiating, down-loaded, vented out of a storage compartment or in combination, these factors become an extension of the raw driver just like its enclosure.
So, now we have assymmetically-loaded multiple subwoofers with random amplitude and phase responses. Dissimilar speakers do not sum as efficiently as identical speakers. There’s more information on this if needed. You now have several woofers, that are different based on their varying enclosures and loading, that sum or don’t sum or may even subtract to a lesser degree depending on your listening position as you move around.
Will multiple subs in different locations play louder? Sure. Even a clumsy design will play louder. How is sound quality? To a trained ear it sounds blurred with less tonal construction.
How about efficiency? All those subs, enclosures and amplifiers will not be as efficient or cost-effective as the first subwoofer.
It is hard to beat the production of a simple approach with a single sub of the highest quality, properly powered, in the optimum enclosure that takes advantage of the most ideal location including the surrounding boundaries.
Its also a good idea to optimize the design efficiency in consideration of our limited charging systems.
That being said, for anyone who wants us to add a ton of subs and amps to their boat, I’m totally on board!
David
Earmark Marine
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