# Setup Stereo Subs



## Phillips (Aug 12, 2011)

Hi can someone please help.
I have gone back to the drawing board for this setup.
The main purpose (95%) is 2 channel music.

My setup
Yamaha Z9
Veritas 2.3i floor standers (mains)
Dual Velodyne Digital Drive Subs

The Yamaha has Stereo outputs + separate distance, level. phase settings.

Thanks in advance


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## PassingInterest (Mar 29, 2009)

I could tell that I missed something, so I looked for a previous discussion and found it here.

I understand that you have a suck-out at 37 Hz, but how did you determine it is a room mode?
If you used a single sub alone and found a drop-out at 37 Hz, it is a Room Mode.

However, if you are running your ported mains full-range together with a sub, you are getting phase cancellations between the sub and the main--especially near the port tune frequency. This may be the source of the 37 Hz problem, or you could really have a room mode at 37 Hz.

Do not run your ported mains full-range with a sub.

If you determine that you have an actual Room Mode at 37 Hz--by running a sweep with a single sub only and no mains--then using multiple subs placed around the room can smooth out the response the room mode issue causes. But, don't mix sub _types_. In other words, don't use a sealed sub with a ported sub, or you will have the same problem of phase cancellations near the port tune frequency.

I'm assuming that you have already tried different sub locations, with unsatisfactory results.
If you haven't, the easy way is to park your sub at the listening position and move the _mic _to potential sub locations around the room during testing.

Hope this helps.


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## Phillips (Aug 12, 2011)

PassingInterest said:


> I could tell that I missed something, so I looked for a previous discussion and found it here.
> 
> I understand that you have a suck-out at 37 Hz, but how did you determine it is a room mode?
> If you used a single sub alone and found a drop-out at 37 Hz, it is a Room Mode.
> ...



Thank you

The 37hz mode was determined by REW + other measurement software.

I have changed to dual Velodyne DD subs with a crossover of 80hz, so basically starting again.

Thanks again


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## PassingInterest (Mar 29, 2009)

How about posting some graphs, so we can see the changes as you try different things?


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