Room response with a Monolith (dip assistance please)

[Buckster]

I have a Monolith, paired with Tannoy Revolution speakers.

xover set to 80Hz.

Room has stairs going up out of it to the next floor.

See response curve below, and corrected curve (possibly ignore the sub 22 Hz readings on the measured after correction as I'm not sure if I actually remeasured that or not)

I recently moved the room around completely by 90 degrees when the Plasma was wall mounted - and that dip at 56 Hz was at 60Hz before room move -it must be a room null, and presumably caused by the stairs up to the next floor ?

I currently have 2 filters, one centered around 40Hz, the other 65 Hz - to remove the 2 peaks. I haven't had that much luck (haven't had much chance to play with it as have to move complete PC into living room etc which is a pain) with RoomEQ so using manual measurements using a Radioshack SPL meter. I then plot the curve, then use RoomEQ to see the shape, size, bandwith of a filter than I intend to use - which I find very very useful indeed.

A lot of people have told me the 60Hz range is about the most important range for "bass" - so obviously having a dip there doesn't help - would I gain from putting say a small 5dB boost around that area ? or would that negatively effect things ?

another thing, my Subwoofer has an analogue dial from 0 to 180 degrees phase, currently I've found that 120 odd degrees is best, or is it really dodgey to have anything other than in or out of phase ?

Please see plot below- many thanks for any help,

Mark.

[brucek]

many thanks for any help

Your response looks pretty good.

It's usually best to first test with the subwoofer only and the mains shut off when equalizing (receiver in stereo, crossover enabled, mains disconnected). Once you get the desired subwoofer target achieved, then turn on your mains speakers to check to see if the crossover area needs adjustment (usually through the phase control and sometimes filtering). Whatever number of degrees is required to obtain the best response is the best value to use. You're lucky to have a fully variable control - many don't.

haven't had much chance to play with it as have to move complete PC into living room etc which is a pain

Not as big of a pain as using the manual method is......... you'll be pleasantly surprised when you finally drag that PC out there and do use REW. Then you'll be able to really see what going on in your room...

brucek

[Wayne A. Pflughaupt]

Welcome to the Forum, Mark!

You should be able to boost some at 56 Hz– it looks too wide to truly be a null. Just look out for overdriving it, but you shouldn’t have any headroom problems with that sub. If the dip doesn’t respond to equalizing, then it’s a true null, and you should then remove the filter.

Regards,
Wayne