Equalizing dual subs

[fergusonv]

I was hoping to get some opinions on equalizing dual subs.
Equipment used - BFD 1124
Dual JBLS S120PII subs

I am unsure of the best method to eq the subs. As I see it I have two options.

1. EQ the subs on the same channel of the BFD
* Pros - Simple setup, 1/2 the work is required to plot and EQ
* Cons - If the subs have different responses I may not be getting the full benefit of each sub, for example If one sub produces 75db at 40hz and the other produces 65db.

2. EQ the subs on seperate channels.
* Pros - Each sub will have flatter response in thier respective locations
* Cons - Thinking that they may cancel each other out at certain frequencies and result in a less flat response when combined.

I was thinking that I could EQ seperatly, measure the combined response and then try to tweak the PEQ settings on each channel to try to get it flater....

This will be my first attempt at EQing dual subs. If anyone would like to share some opinions on the best way to do this or share thier experiences I would appreciate it.

 

[Resident Loser]

The operative word being...

...equalize...not average out, approximate or split the difference...EQ them separately and be done with it.

Frequency cancellations occur when the signals are out-of-phase, optimizing the response curve for each, at it's individual location, will not do this.

jimHJJ(...hope that helps...)

 

[fergusonv]

Does anyone know if the Velodyne SMS1 eq's eqch sub independently or if it eq's them together without changing the individual reponses?

 

[MACCA350]

The SMS-1 can send up to 3 subs the same EQ'd signal. If you want individual EQ's for each sub you'll need an SMS-1 for each sub which you can daisy-chain for easy operation. What you can do is use a single SMS-1 connected to one sub at a time to find the best location for each sub, then connect all of them to adjust the overall response since this is what you'll hear(the combined response). using multiple SMS-1's is similar to this except you EQ each one at their placement then EQ the master with all running to EQ the combined response.

cheers

 

[Resident Loser]

While it wouldn't be...

...What you can do is use a single SMS-1 connected to one sub at a time to find the best location for each sub, then connect all of them to adjust the overall response since this is what you'll hear(the combined response). using multiple SMS-1's is similar to this except you EQ each one at their placement then EQ the master with all running to EQ the combined response.

cheers

...the most absolute, accurate methodology, a savings of around $800USD (for the second SMS-1)might offset the potential few dB of error...of course, that's if the determined locations for the two subs comply with the WAF or other aesthetic concerns.

jimHJJ(...then I guess two units would be the way to go...)

 

[fergusonv]

Update:

I finally got around to EQing my sub setup since getting a matching sub. I ended up trying it both ways, EQing both subs together and independently. The subs are indentical and are placed symetrically in the room and each is corner loaded in the front of the room (the additional sub added 5db). Both subs shared a peak around 35hz but did not share common peaks otherwise. Best resonse was obtained by EQing them seperatly and level matching about 4db down per sub. When they are running together it's about 1db hot. So for what it's worth in my room it is better to eq subs indepentently.