jpeg of left sub what do you think ?

[Ashmanuk]

I have been playing about with REW/BFD fbq24/96, way out of my depth but having lots of fun in the process.

I Eq`d left sub then right sub, though another member on AVS forums said i should EQ with both sub,s connected at the same time "don't know what you guys think on that one?

The right sub has some dips which i can not get rid of by placement as i need to keep them in the corners, can i ask what you think of this image and would EQ both subs together resolve mask it.

http://img267.imageshack.us/img267/7330/rewjpegqf0.jpg

[russ.will]

Originally Posted by Ashmanuk

I Eq`d left sub then right sub, though another member on AVS forums said i should EQ with both sub,s connected at the same time "don't know what you guys think on that one?

Each sub may perform absolutely flawlessly by itself, but it's the combined response of the pair at the listening position that matters. You cannot predict this by EQing them individually to flat and assuming that turning them both on won't result in some sort of reinforcement and cancellations in the response.

Therefore you must EQ the pair together to provide a final result, but for the same reason you must also include the main speakers. It should be noted that phase cancellations are a likely source of dips in the response and these cannot (or rather shouldn't) be corrected by using EQ.

I banged on about setting up dual subs in this thread.

Russell

[Ashmanuk]

WOW Russel,

Very well written article, How long did that take to test all those subs and positions.

Hearing those test tone`s all day must of giving you a massive headache

I will test both subs together with REW, then I will add the front channels in to see the affect, as that does make a lot of sense about cancellations etc...

Thank you for your comments.

[russ.will]

Originally Posted by Ashmanuk

WOW Russel,

Very well written article, How long did that take to test all those subs and positions.

Hearing those test tone`s all day must of giving you a massive headache

I will test both subs together with REW, then I will add the front channels in to see the affect, as that does make a lot of sense about cancellations etc...

Thank you for your comments.

Thanks for your kind words.

It didn't take as long as you might imagine - The SMS-1 isn't as versatile as REW in some respects, but having it's own phase and polarity controls that can be applied to both subs simultaneously was a real boon.

Russell

[suniil]

sorry off-topic, Congrats russel [guess!]

Ashman: Russel pointed to the right direction, I've gone thru this process several times. Some of AVSF posts are misleading, which i followed earlier! Calibrating the subs seperately and running together created all sort of problems & nightmare

Originally Posted by russ.will

Russell

[russ.will]

Originally Posted by suniil

sorry off-topic, Congrats russel [guess!]

Cheers!

Russell

[Ashmanuk]

Oh no not another guessing game by russ.will remember the one about you trying to get me to guess the SMS-1 "THANKS" LOL

[IronGiant]

Originally Posted by Ashmanuk

though another member on AVS forums said...

See what you get for getting advice elsewhere

Dave

test edited

[Nimby]

A common problem with separated dual subwoofers is mutual reinforcement and cancellation dependent on their spacing and any asymmetry in their positioning. This is due to the long wavelengths involved at low frequencies. When waves meet in phase they reinforce each other. When they are out of phase they cancel. This result in troughs and peaks in the frequency response. Reflections from room boundaries further complicate the issue since the reflected waves may be in or out of phase with the direct acoustic output. (Or partially so)

Ideally one should treat multiple subwoofers as a unit during testing. Bringing them together between the main speakers maximises their performance (thanks to mutual gain) while minimising phase issues. That said, widely separated subwoofers might be tuned (using their spacing as a variable) to minimise response problems at the listening position.

[Ashmanuk]

Thanks Nimby,

You have burst this big bubble i once had



As for you Mr Irongiant stop it

[Nimby]

Originally Posted by Ashmanuk

Thanks Nimby,

You have burst this big bubble i once had

Would you care to elaborate?

[Ashmanuk]

Hi Nimby,

Just a joke, I thought i was getting on top of things and then you through all that at me.

I find so many people on here know what they are talking about its great to see.

What was the congrats for russel for