Multi-Driver Sub

[MillerLiteScott]

I was listening to music in two channel today while starring at my RTi10's with the grills off.

(No sub because I sold it. My wife won't let me get a new one untill I sell enough stuff to buy a new sub.)

I have notice a modular construction to the current polk speakers lines. It occured to me why not have a subwoofer with 4 of the 7" drivers in it. All four speakers would have the surface area of more than 2 12" subs in a single box and the 4 would produce tighter quicker bass than a single 12 or double 12. You could also have a sub with 6 7" drivers ala RTi12 etc. The same could be true for the LSi Series or the monitor series.

I used to play bass ( before I got married ) and I had a Ampeg SVT10 which had 8 10" drivers with each pair in a sealed chamber. I believe the two drivers per chamber were wired out of phase so when 1 driver was going out the other 1 was going in( I could be wrong). This cabinet is and has been pretty much the industry standard for @30+ years. 8 times out of 10 you will see a bass player playing and Ampeg SVT10 on stage. It seems that multiple smaller driver could offer more in a musical sense. I do think larger drivers may be more beneficial in a HT setup to produce the lower frequencies.

I think my ideal floor standing speaker would be a LSi9 as the top end and pair of LSi quality 7" or 8" drivers to handle the low end in the same tower but in a seperate chamber. I would still want a sub crossed over @ 60htz to fill in the low end and again it could be 4 or 6 of the 7" or 8" drivers tuned to play the low frequency powered by their own amplifier.

I am just thinking out loud and wanted to see if anyone thought that this was viable sub configuration or if I was just wasting brain waves.

Disclaimer
I have absolutely no technical backround to back up my idea.

[surfntomm]

first of all 4 7" drivers would have quite a bit less area than 2 12" so thats the first mistake, other than that i dont know :(. interesting thought though.

[MillerLiteScott]

Lets say that 2 7' drivers have a comprable surface area to a 12" driver.

I would think 2 7" drivers would have more surface area than a 10" driver.

[GV#27]

Volume displacement would be a better way to compare multiples of drivers than just surface area.Generally larger woofers have greater excursion capabilities than smaller ones.So even if the 2 7"s had a larger area the 10" would still be able to move more air.Also the 10" would be able to reproduce lower frequencies because of it's lower natural resonance frequency.The 7"s would need some form of EQ to go as low in the bass.

[MillerLiteScott]

I guess I will stick to re-doing kitchens and baths and let the speaker guys build speakers.

[GV#27]

Now I know who to ask when I have a plumbing question.Just did some bath reno's and had to learn as I went.

[dudeinaroom]

just so you know 2 7" drivers would have an area of 76.93 sq. in. and a single 12" would have 113.04. So 3 7" would be about 2 more sq.in. surface area. also you have to consider the depth of the cone witch will add a little more surface area(I just crunched numbers as if they were flat circles). Remeber when dealing with round objects it takes 4 times x" circles to get a circle that is twice x" diameter.( 2 - 6"speakers do not = a 12" speakers 4 - 6"ers have the same displacement as a single 12")
I know shut up already.

Later,
Dude

[MillerLiteScott]

Ok, How about making subs with big drivers and forget about the multiple small drivers.:D

Just call SVS. end of story.

[surfntomm]

bigger drivers = more mass and less accurate and responsive due to a little something called momentum

[kingkip]

bigger drivers = more mass and less accurate and responsive due to a little something called momentum


Way too simpistic my friend. If that were true then every manufacturer would sell subs with tons of small drivers. There are many other factors that go in to the sub design, ie what about sealed vs ported? Do any of the other T/S parameters have anything to do with accuracy? Sounds logical at first, but falls apart against any kind of examination. By the way, IB subs typically have large divers, and they are some of the most accurate subs I have ever heard.

[GV#27]

The use of multipule small drivers has advantages in the 50hz region and above.For instance it allows the use of a narrower baffle and greater power handling because power is being shared by two or more voice coils.
But for deep bass bigger is better.