Multiple Subwoofers in one cabinet...

[christommes]

I recently purchased 8 subwoofers from partsexpress for my home THX system....i built seperate enclosures of around 4 cubic feet for all of them...

Overall the sound is mindnumbing...but there are occasions where say in jurassic park...the dinosaur is amazing but still not as dynamic as I would like it to be....

I am considering buying another 8 speakers...but I want to know...if I place 2 drivers in each cabinet would that effectively drop my box volume down to 2 cubic feet even though the share the common 4 cubic ft chamber?

I dont want to start cutting holes in these boxes for no reason that is for sure...

thanks

 

[Francious70]

You're not happy with 8?!?!?!?!?! Are you deaf??

 

[jaxvon]

Which subwoofer drivers did you buy? Are you SURE it isn't a placement issue?

Edit: Have you thought about reducing the number of woofers you have going? You have so many running, it might a cancellation problem.

 

[nibhaz]

I recently purchased 8 subwoofers from partsexpress for my home THX system....i built seperate enclosures of around 4 cubic feet for all of them...

Overall the sound is mindnumbing...but there are occasions where say in jurassic park...the dinosaur is amazing but still not as dynamic as I would like it to be....

I am considering buying another 8 speakers...but I want to know...if I place 2 drivers in each cabinet would that effectively drop my box volume down to 2 cubic feet even though the share the common 4 cubic ft chamber?

I dont want to start cutting holes in these boxes for no reason that is for sure...

thanks

I never knew there where THX certified kit speakers??????????

 

[christommes]

okay so everyone has danced around the answer....for one...it is a prototype, and when i say THX i dont mean certified i just mean, people shouldnt have to shell out a million dollars to have a decent system, so i am working on developing a super system with 8-16 subs alone for under $700 this is my goal and so far besides the forum answering the question i have been right on track...

sound is trust me, mind numbing.....but the issue is perhaps an amplifier one...i purchased two power amps so i am waiting on them to arrive...i really just wanted to know also for future projects the impact of placing multiple drivers in one cabinet...

thanks

 

[soniceuphoria]

When building mutiple driver enclosures you want to seperate each driver into its own chamber with baffles. There are a couple of reasons for this, such as driver crosstalk. Which is the movements of one driver canceling out the other. The other is the fact that the speakers were designed to operate in a box of a certian cubic feet and increasing or decreasing the size can have a dirrect effect on the frequency response and actual output. There are cases where two drivers occupying the same air space can be a good thing, such as a bandpass box. But in the case of a sealed box your best bet will be to build a box with each woofer seperated by baffles in its own chamber, built to or near the manufactures specifications for the best results. Also make sure that all the speakers are opperating at the same phase (positive and negative going to the correct terminals). And as you have apparently found out, driving 8 subs takes a buttload of power. Powerful PA amps are your best bet to power that many subs cheaply. I hope that this helps you out. Enjoy your wall of subs.
Greg

 

[genesound]

...if I place 2 drivers in each cabinet would that effectively drop my box volume down to 2 cubic feet even though the share the common 4 cubic ft chamber?

Yes it would.

 

[MACCA350]

I have design drawings for the 'House Wrecker' by Decware, see here. It can load up to 4 18" subs. Here is what they say about it:

Here is the only box that can compete with a full size imperial folded horn cabinet without the complexity to build and use. This enclosure will properly load rooms between 144 sq. ft. and 32,000 sq. ft. with extremely serious bass. Enough to cause minor damage in homes - hence the name!

Use one to four drivers to achieve a 7th order band pass or ultimately a DUAL COMPOUND ISO SLEDGE HAMMER !!

Responses range from narrow bandwidth to wide bandwidth with typical responses down to 13 HZ on the all three models. Box can be built for 8's,10's, 12's, 15's or 18 inch woofers. Note: The design is for a 15, however the the box can be scaled down (and so the performance) to smaller drivers but you will have to specifically tune anything below the original 15" design.

A well designed enclosure can mean the difference between an ok sub and a great sub in ported designs. Apparently they levitated a rug off the floor with this thing loaded with just 1 sub One day I'll get around to building it up and see what it can do

cheers

 

[MBauer]

Some suggestions

okay so everyone has danced around the answer

thanks

I wouldn't say anyone has danced around the answers? To best answer the questions you posed, people needed some clarification (or wanted to comment on your posting).

So I will answer yor question (a repeat of course) and the answer is yes, another driver will alter the capacity of your enclosure. It will just displace more air, thereby giving you less internal volume available.

Several things I didn't read. Did you measure the output? There are several DVD's and CD's availalbe that will output test tones so you can measure the output of your speakers. Combining those with an SPL meter from Radio Shack will give you a very good idea of the systems frequencey response. It could well be that they are working fine and the bass you seek is not present in the recording.

Have you tried changing the location of the sub's? That has a great impact on how they will sound and the levels they will achieve.

What did you construct the enclosures from? Internal baffling? These are all valid pieces of information to give you assistance.

 

[zilla]

My god man, we need pics!!!!