Wattage of more than 1 sub

[Subcenter2009]

Hi everybody.

I have been reading these threads regularly.

Since I am not an expert, I want to ask a longtime doubt if I may.

Suppose I have a Home theater in which I have 2 or more active subwoofers firing in phase,

Let's say 2 50 watt amplifiers driving two 8" woofers at half volume..

then, what will be the resultant output in watts?

How does one calculate this accurately?

So are two woofers better than one?

Put this way, are 2 50 watt subs better than one 100 watt sub?

Because, if they are indeed better, then I have the option of placing them in two places in the room and maybe avoid nulls to an extent.

Please voice your views..

Belated Onam wishes,

Subcenter2009

 

[Subcenter2009]

Hi,

I am not sure what this means.

Someone told me that having 2 or more amplifiers driving 2 or more speakers in phase results in a.. note this.. a Logarithmic increase in total power output.

So 50 + 50 is not 100 watts as one would assume. But much more.

How does one calculate that?

Forgive my crude language. I hope all of you get what I am trying to say.

With best wishes,

Subcenter2009

 

[doors666]

you'll get a 3 db gain by using two identical subs over a single one.
A single sub for 1000$ will peform a lot better than 2 subs at 500$.
Dual subs are better for cancelling out room responses, but the placement is a pain. This is what i've heard/read, but not experienced.

 

[grubyhalo]

...
Someone told me that having 2 or more amplifiers driving 2 or more speakers in phase results in a.. note this.. a Logarithmic increase in total power output.

So 50 + 50 is not 100 watts as one would assume. But much more.

How does one calculate that?

Forgive my crude language. I hope all of you get what I am trying to say.

With best wishes,

Subcenter2009

If I'm not mistaken, the logarithmic increase is in the sound level of the speaker (loudness?!), not the power output. I'll let the experts take it from here and explain it properly...hyeah:

 

[Subcenter2009]

you'll get a 3 db gain by using two identical subs over a single one.
A single sub for 1000$ will peform a lot better than 2 subs at 500$.
Dual subs are better for cancelling out room responses, but the placement is a pain. This is what i've heard/read, but not experienced.

Thank You, dear Doors,

So, a $1000 sub should win in the end because it is obviously made with superior stuff.

I also understand that if the workmanship is the same, and one is lucky enough to be able to optimally place the two smaller subs (yes, Identical), in spite of all the other furniture in the room, then the advantage is that one has good bass in more places than if he had a single subwoofer.

Thanks again,

Subcenter2009

 

[Subcenter2009]

If I'm not mistaken, the logarithmic increase is in the sound level of the speaker (loudness?!), not the power output. I'll let the experts take it from here and explain it properly...hyeah:

Hi,

I meant speaker level too.

Thanks,

Subcenter2009

 

[Subcenter2009]

Hi,

I would really like to know if there is some tool or formula that one can use to predict the sound level when two or more speakers are firing in phase.

Is there any online resource one can look up?

I'm hopeless with maths.

Is there any way to explain it in semi layman's terms which is not Greek and Latin to lay users?

Thanks a lot for speedy replies,

Subcenter2009

 

[doors666]

Hi,

I would really like to know if there is some tool or formula that one can use to predict the sound level when two or more speakers are firing in phase.

Is there any online resource one can look up?

I'm hopeless with maths.

Is there any way to explain it in semi layman's terms which is not Greek and Latin to lay users?

Thanks a lot for speedy replies,

Subcenter2009

you'll get a 3 db gain in SPL when using 2 subs of the same type. A 6db gain is perceived as double volume. Whether you use 2 subs or use 2 drivers in the same sub, the gain is 3 db. That means that if you are listening at 90db with 1 sub, adding one more sub will make it 93db.

 

[Subcenter2009]

Thanks, Dear doors.

So, there is definitely an advantage.. just as I thought in multiple drivers.

The challenge is to make them fire in phase, especially if they are from different makers.

A speaker manufacturer based in Chennai, who was known for their quality active speakers, used to manufacture active subs designed like a magnetically shielded table on which one can keep his TV etc. There are woofers from 2 to any number firing downwards under this table. At that time they used to believe in only 8 inch drivers. Each woofer has its own active crossover and amp. The woofer cabinets are about 1 foot away from the floor. All in seperate sealed cabinets, pointing downwards. One of the better systems I've seen. The reason I mention this is because I was wonderstruck by this novel method of getting fantastic output thro' multiple drivers and amplifiers.. Still a lost chord somewhere in the recent past..

but a single sub will reduce clutter as per W.A.F. (Womens air force?)norms.:lol:

May people using this site gain from this info.

Yours,

Subcenter2009