My Measured Sub-response with RoomEQ

[Buckster]

Mmmm - it suggested some filters which I applied (and I can't really remember whether this is before or after - but it didn't make much difference)

but am I right in thinking th BFD is almost redundant ?

The "hole" is there no matter what - its a room null - not a lot I can do really is there ?



thanks, Mark.

[Neil Davidson]

You can move your seating position or the sub to try and improve things. EQ can't get rid of the dips.

Neil

[Badger0-0]

Yes it can, if you boost instead of cut.
Of course there is the tradeoff in that you're increasing the load on the sub's amp.
I'm currently thinking of boosting my Ultra by large amounts and probably will when I get round to it..
I did it on my PB10 with no detrimental effects.

[AngelEyes]

Would you consider such a high boost that wide?

I have done it in the past on small narrow troughs but nothing like that. I would say moving the sub or closing the door is more likely to make a significant difference.

Adam

[Buckster]

no doors (well one - but thats shut)

stairs go into the room without any door if that makes sense.

I've moved the sub just about everywhere - EXCEPT for in the middle of the room which wouldn't happen - and get the same hole - just slightly different frequency.

Mark.

[Badger0-0]

Originally Posted by AngelEyes

Would you consider such a high boost that wide?

I have done it in the past on small narrow troughs but nothing like that. I would say moving the sub or closing the door is more likely to make a significant difference.

Adam

Yep, I'm a risk taker

Seriously though, my Ultra has plenty of grunt and is only set halfway on the gain, so I doubt it would be a problem. I would, of course, look for signs of a problem (heatsink temp etc).
I'd be much more wary if I wanted to boost the very bottom end though.
I'd certainly suggest a 6dB boost wouldn't be a problem, which should at least improve things.
But as you suggest, it's a last resort.
My post was only to say that you can boost, albeit at a risk.

Buckster, I accept no responsibility if you decide to do it, it's completely at your own risk.
As I said, I think a bit of boost won't hurt, but I'm just covering my ass

[Buckster]

thanks mate

I'm on about 1/4 dialled up on the Monolith gain wise- so probably quite a bit spare ....

Mark.

[Badger0-0]

The way I look at it is, if you do boost, surely that's not as bad as running your sub full belt, which it should be able to do, albeit at a strain and risking bottoming the driver.
I'd try a bit of boost and keep an eye on the heatsink temp.
It might go slightly warmer, because your asking a bit more at normal TV bass levels, but it should never get more than say 40ishC and even that's probably too much.
That's a bit of guesswork, because I don't know how warm it runs now.
If it's cool (and a quarter gain suggests it should be), it would suggest you have plenty of headroom, as you say.

[recruit]

With that sort of suckout which is atleast 15+db lower than the rest of the frequencies i would certainly try other locations for the sub 1st, as with such a wide band of frequencies boosting will have little or no effect anyway, and you run the risk of damageing the sub

If you are looking at boosting make sure it is above 50hz and no more than +3db.

[Badger0-0]

If you are looking at boosting make sure it is above 50hz and no more than +3db.

I'm not looking for an argument, honest, but can you say why you say that?

Have you ever tried boosting by significant amounts?

The reason I ask, is that I boosted my PB10 over about a 25hz bandwidth (55-80) by 12dB, at least (I can't remember exactly) and never had the slightest problem. The heatsink didn't even get any warmer than slightly warm to the touch.

Of course there may be transients in power demand that are a bit naughty (and even then I doubt they will max out the amp), but particular frequencies are only heard for fairly short periods of time, IMO.

I'd love to hear a definitive answer to this from the experts/manufacturers, although I accept it's probably down to the individual setup and room.

[recruit]

sorry i have to delete what i just put in here as it could be copyright breach, giveing my self a slap on the wrist !!

PLS refer to the BFD guide for more info !!

[Badger0-0]

Originally Posted by recruit

sorry i have to delete what i just put in here as it could be copyright breach, giveing my self a slap on the wrist !!

PLS refer to the BFD guide for more info !!

Yes, all totally good advice
I would totally disagree with boosting a bad null, not having an effect though.

I've done it, to very good effect and I'm going to do it with my Ultra with no qualms

It's all good for info though, which is what it's all about

[Badger0-0]

Originally Posted by recruit

sorry i have to delete what i just put in here as it could be copyright breach, giveing my self a slap on the wrist !!

PLS refer to the BFD guide for more info !!

I was wondering what the mail was about

No worries mate

[Buckster]

thanks guys - when wife has gone to bed - I'll experiment with 2 other possible locations - I'll let you know how I get on

[Buckster]

moved it to the other side of the room - no time to do an EQ sweep -but will try later.

Interestingly - I presume the screws holding the driver in should be as tight as possible ?Mine were rather loose ... took about 6 full rotations to go tight (all of them)

Mark.