# harman multisub method



## atledreier (Mar 2, 2007)

Hi, guys.

I've recently moved house and have a new cinema room in the making. Been pondering sub placement for a while, and the old Harman multiple sub whitepaper surfaced in my mind. I have a great opportunity to try this placement with two or four subwoofers in they (near) ideal theoretical locations. 

My question is, have anyone actually tried this placement (centered on front and rear wall, alternatively centered on all four walls)?

My system, should it matter:
The room is 8,1m long, 4m wide and 2,4m tall. 
My mains are in my signature, basically MTM with Beyma 15" pro drivers and a Beyma horn.
Subs are four JBL 4645B with alternate tuning and 2242H drivers, and one JBL 4645A (probably won't bother with this one).

The first configuration will most likelyconsist of two pairs of subs stacked centered on teh front and rear walls.

The theory is that this will even the response across teh seats, and can then easily be equalized flat.


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## bpape (Sep 14, 2006)

I've seen it done and work very well. I've also seen it done and not work much better than deliberate assymetric placement. The big difference was how symmetric and plain rectangular the room is. 

Bryan


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## atledreier (Mar 2, 2007)

Ok, that's a bummer, because my room isn't very symmetric. I'll give it a shot anyway.

Any experience with stacking subs to kill the floor/ceiling node?


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## bpape (Sep 14, 2006)

That can be helpful or even sometimes just raising one off the floor a bit. 

In asymmetric rooms, many times, the asymmetric method works best. Set up one, then deliberately set the next, then next, then next with none of them being close or of similar spacing between walls. To really get this right, you need continuous phase adjustment rather than just a 0 or 180 switch.

Bryan


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## atledreier (Mar 2, 2007)

I have full parametric EQ capability on all subs. I'm also liking the simulated response of stacking pairs on either side of my center channel, so I will try that too. 

Interesting times!


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## bpape (Sep 14, 2006)

You can try that certainly, though understand that putting 2 massive columns like that next to your LCRs, they're going to see basically a wall very close to them which will cause some other issues that the sim won't account for. Worth a shot as long as you don't herniate yourself doing it.....

Bryan


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## atledreier (Mar 2, 2007)

I see it as a baffle wall, even. Might be beneficial. If I put the LCR and sub pairs right up against each other in a more or less coherent wall they will just fit inside my screen frame. Worth a shot.

I think I'll try all three methods ( Harman, Geddes and stack) and post the results in this thread.
Now, if only the mail would hurry up and bring me my amplifiers!


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## bpape (Sep 14, 2006)

Up to you. A baffle wall is a good idea for speakers that were designed to be used in one, not so much for those that weren't. Plus, you'd get both sides of your center and one side of your mains - hard to say what it would do.

Bryan


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## atledreier (Mar 2, 2007)

Well, it should be easy to extend the wall on either side of the L and R speakers out to the side walls. I'll need to experiment, I haven't done a single measurement in this room yet.

I have full freedom when it comes to crossover and EQ on all my channels so adapting to a baffle wall should be doable.


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