which frequencies?

**dimmie** · **09-18-06, 01:47 PM**

Quote:

brucek wrote:

The mesaured distance is no doubt correct. Once set, we normally then adjust the subwoofer phase control to correct to the best resulting signal around the crossover region.

If you don't have a phase adjustment, you can substitute a time delay adjustment on the sub which will act as a reasonable approximation for a phase adjust.

You have demonstrated this in your graphs in that as the time changes the crossover region gets better.

brucek

I do have a phase switch ofcourse, I'll take the measured distance and play with the phase. But I also realized that I entered a new filter at that point, which I totally forgot about yesterday. So I'll have to turn it off and see what I can do with phase alone.

The least dip at the x-over point is the best phase, right?.

thanks

dimitri

**brucek** · **09-18-06, 02:18 PM**

Quote:

The least dip at the x-over point is the best phase, right?

Yep, and as you've noticed, after you set the best phase, if it's only a switch and not variable, then you might tweak the distance a little if its effective in removing more of the problem. Usually before you play with either phase or distance, it's best to move the sub around to different locations, but this is sometimes not possible because of WAF or layout..

**dimmie** · **09-18-06, 03:56 PM**

It's a variable. As soon as I get a chance I'll work on it.

Moving the sub right now, is not an option. Taking into consideration that I have baby-twins and everything fragile in the house has to have some barrier in front of it

. It's pretty safe where it is, and it's not in the way.

Dimitri

**dimmie** · **09-21-06, 05:01 PM**

Hey bruce,

I've been adding some extra filters, I'm at 10 now.

Is 12 filters the maximum amount?, because I'd like to trie and experiment with house curves. But I think my response is not smooth enough to do this(I think).

Bass response is pretty good now, but I'd just like to give it a go.

**brucek** · **09-21-06, 05:56 PM**

Quote:

Is 12 filters the maximum amount?

Yeah, 12 is the limit. Most people can get the response they want in that amount......

**JohnM** · **09-21-06, 06:57 PM**

If you are keen you can loop the output of one channel to the input of the next and have 24 filters.

**dimmie** · **09-23-06, 05:41 PM**

Yeah, I think I understand.

Just connect input 1 to input 2........e voila!.

I'm starting from scratch to see if I can apply filters more effectively now, and hope I won't need 2 channels.

**dimmie** · **09-23-06, 05:55 PM**

five filters.

**brucek** · **09-23-06, 06:12 PM**

Quote:

five filters

Yep, good job. Whenever I read someone ask about using more than 12 filters, my reaction is, "try harder"....

That's a really good response. Now to add a house curve, the easiest method for you would be to turn up your subwoofer amplifier a few dB and then use a few filters (including the ones you're using if necessary) to slowly drop the area from ~40Hz to ~90Hz if possible.

Something like the target shown below:

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brucek

**dimmie** · **09-23-06, 07:31 PM**

Ok, thanks for your time. and the graph.

I'll get around to it tomorrow

for now.....

**dimmie** · **09-24-06, 06:10 AM**

8 filters, I guess this is as flat as I can get it with this number.

The waves in between 15 and 30 hz. aren't gonna be annoying, are they?. I wouldn't know any material at these frequencies to test it.

Now on to the house curve.

**dimmie** · **09-24-06, 02:54 PM**

Brucek,

Regarding the input level on the BFD, mine is probably set too low. Because of my sub's power, the best way to set it up is by turning down on the av amp, and adding extra gain on the sub itself. Because if I set the av volume at say: 0 or +5 the sub will always be too loud, even at it's lowest gain.

And the bfd probably needs at least 0 on the av amp for it's input(probably higher)

I'm asking this because I was reading your review on the BFD and you mentioned that the quietest signal might not be processed properly when the input level is set too low.

The most led's I've seen are 2 maybe 3 green.

thanks

dimitri

**brucek** · **09-25-06, 08:28 AM**

Quote:

8 filters, I guess this is as flat as I can get it with this number

The response using 5 filters would have been quite sufficient. You don't need to get it ruler flat. It's just not neccessary.

Quote:

Because of my sub's power, the best way to set it up is by turning down on the av amp, and adding extra gain on the sub itself. Because if I set the av volume at say: 0 or +5 the sub will always be too loud, even at it's lowest gain.

I don't really understand why the subs volume doesn't dial down to zero? You should be able to completely control its level with the gain dial.

Quote:

The most led's I've seen are 2 maybe 3 green

Even when you play a bass heavy DVD at the loudest you would ever listen? Be sure to be monitoring the BFD's input LED's and not the output LED's.

brucek

**dimmie** · **09-25-06, 11:32 AM**

Quote:

The response using 5 filters would have been quite sufficient. You don't need to get it ruler flat. It's just not neccessary.

ok, back to five.

Quote:

I don't really understand why the subs volume doesn't dial down to zero? You should be able to completely control its level with the gain dial.

I checked again yesterday, with the filters it's easier to control the sub.

Quote:

Even when you play a bass heavy DVD at the loudest you would ever listen? Be sure to be monitoring the BFD's input LED's and not the output LED's.

I'll recheck, weith the BFD in bypass

I made a start with the housecurve..

**dimmie** · **09-26-06, 06:15 PM**

Which would you say is the best phase?.....

Is the area past 100 hz. important?

these are from 0 to about 75 degrees approx. in five steps

**brucek** · **09-26-06, 07:02 PM**

I like door number three.

Why don't you filter that peak at 78Hz.............

**dimmie** · **09-27-06, 06:41 AM**

I already did, but I bypassed that filter to get a clear crossover picture.

Thanks.

I'll get on to the house curve.

**dimmie** · **09-28-06, 06:41 AM**

Man, I can't get that crossover response back...I changed some things yesterday.

A big dip at about 150 nhz. which won't go.....

**dimmie** · **09-28-06, 03:00 PM**

I'm upping the volume on the sub, for the housecurve.

And this is what happens.....the region from 100 hz. and up rises with the sub volume.....

Cross is at 100 hz.......

It seems it's still the sub after 100 hz.

any idea?

**brucek** · **09-28-06, 04:40 PM**

Quote:

any idea?

lower the crossover to 80Hz and up the volume....... retest

**dimmie** · **09-29-06, 06:26 PM**

Here's 80 and 100 hz. cross respectively.

I think you're right ken.......at 80 hz. x-over it seems the sub level is unaffected after 80 hz.

Is this normal for a 5.1 receiver?...

Thanks

Dimitri

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