First time user - mixed results

[brucek]

Regarding my dip, take a look at the second graph in this post:

If when you add your filters, and the graph and dip looks as it does in the predicted response, then it would be wise to add the mains and see if it persists..... only then do you decide on an action..

brucek

[lovingdvd]

Last night I had some good success with REW and BFD as I dug in and starting to dial things in nicely.

With the sub alone, I got the response to be nearly perfect! However this beautiful response curve fell apart once I added added the mains back in. So essentially at that point I had to start all over with the filtering process to account for the subs+main.

I noticed I had some dips and fall off (in a sharp-like zig-zag fashion) in the 70-90hz range. Then i dawned on me. I did not have the HSU sub's crossover OUT - I had it engaged at the maximum xo of 90hz.

I had done this previously because when watching movies I noticed some localization coming from the sub.

Interestingly, when I turned the subs xo switch to OUT, the dips were gone and in fact were a bit too high in that 70-90hz range, but I brought those down with some more filters.

So in summary with the sub's xo switched to out and my latest filters, I have things very flat at about +/- 2dB from 20-90hz with no dips or peaks whatsoever!

However... Now I noticed that I have a challenge with the localization again. My sub is only 6 feet away behind the couch and there is no other place in the room for it. I have to listen a bit more closely but I believe I am now getting muffled voices and so forth coming from the sub in this configuration.

I guess this would make sense, because with a proper rolloff one still has a fair amount of dB of 100+hz coming from the sub and its my understanding around that range is when you start to pick up localization.

What is the best thing to do if your calibration shows very good tracking to the target, but results in too much localization?

I have not yet added a house curve, which I plan to work on tonight. With the house curve I'll likely wind up with a good 5-10dB push in the 20-30 range, or more of a linear slope in which case the upper end (higher hz) will still be 5-10dB lower than 20-30hz.

So I'm thinking that this will result in me needing to turn the sub down a bit, and therefore decreasing the dB of the localization frequencies in the sub?

Another thing I am considering is just put the xo on the sub back in and leaving it at 90hz, perhaps even toning things down a bit. This will result in the bass being a bit shy in the upper end of the sub's range, but would be better I think than having localization.

Its a shame I have no way to boost the 80-100 range at the main speakers. This would allow me to use the xo switch on the sub to cut the 80-100 range back at the sub while increasing it at the receiver/mains so the net affect would still be the right amount of bass in that range.

Humm. Anyone know if I may be able to get this type of boost in the mains by just turning up the Bass knob on the receiver itself? If doing so wouldn't affect the sub than perhaps that could work?

At any rate any recommendations for how to handle this would be much appreciated. Thanks!

[brucek]

What is the best thing to do if your calibration shows very good tracking to the target, but results in too much localization?

Normally, you would just lower the crossover setting, but I believe 80 is as low as your receiver allows.

However this beautiful response curve fell apart once I added added the mains back in.

Are you sure you don't have a setting with your mains that is adding some low end to them even though they're set to small. Many receivers have a setting such as that. Adding the mains shouldn't mess up your sub that much....

Another thing I am considering is just put the xo on the sub back in and leaving it at 90hz

Double crossovers is not a good idea. I would scrap that notion. Let your receiver do all the bass management.

brucek

[JohnM]

Try placing a manual filter in the BFD at 130Hz or so, not too narrow (BW around 8-10) and use that to lower that range until you no longer get the voices breaking through, should have less influence through the crossover region than leaving the sub's filter in place.

[lovingdvd]

brucek wrote:

Normally, you would just lower the crossover setting, but I believe 80 is as low as your receiver allows.

My receiver allows me to set the xo at 40hz, 60hz, 80hz, 90hz, 100hz, 110hz and some higher. Do you think it would be worthwhile to do some tests with it set at 60hz?

Are you sure you don't have a setting with your mains that is adding some low end to them even though they're set to small. Many receivers have a setting such as that. Adding the mains shouldn't mess up your sub that much....

Thanks for the tip I'll read through the manual but I am not aware of any such setting.

I don't have the graph or data in front of me, but as I recall, when I test the mains only it shows I have about 50-60dB of bass from about 35hz and up WITHOUT the sub turned on (based on the receiver set to output 75dB). I agree is seems like a lot of influence.

Double crossovers is not a good idea. I would scrap that notion. Let your receiver do all the bass management.

Make sense. Too bad the receiver seems to be doing a fairly poor job in this respect for some reason...

[lovingdvd]

JohnM wrote:

Try placing a manual filter in the BFD at 130Hz or so, not too narrow (BW around 8-10) and use that to lower that range until you no longer get the voices breaking through, should have less influence through the crossover region than leaving the sub's filter in place.

Sounds like a good idea. How is this different than, say, engaging the subs xo and having it set to its max of 90hz xo?

[cyberbri]

With the xo set to OUT/on now, did you run any tests comparing the sub + mains with the sub's phase at 0 and 180 degrees? You could end up having to choose the lesser of two evils with regards to the effects, but you should at least know what the freq response is and choose what works best.

And yes, measuring the sub alone and using cuts above 100Hz could possibly help with the problem of being able to localize of the sub.

[lovingdvd]

cyberbri wrote:

With the xo set to OUT/on now, did you run any tests comparing the sub + mains with the sub's phase at 0 and 180 degrees? You could end up having to choose the lesser of two evils with regards to the effects, but you should at least know what the freq response is and choose what works best.

And yes, measuring the sub alone and using cuts above 100Hz could possibly help with the problem of being able to localize of the sub.

Yes I did try with the phase at 0 vs. 180 (with the sub XO enagaged at 90; did not do this comparison with the xo OUT). After much experimentation I concluded that the phase in its normal setting (0?) was by far best. For some reason using the 180 phase resulted in a shortage of bass in the 20-30 range (which I don't understand because my mains don't go down that low anyway) and also caused some other issues like a rattle/buzz that seemed to be coming from my left front main speaker. In just listening to the sweep I could hear that it just didn't sound right.

[lovingdvd]

brucek wrote:

Are you sure you don't have a setting with your mains that is adding some low end to them even though they're set to small. Many receivers have a setting such as that. Adding the mains shouldn't mess up your sub that much....
brucek

brucek - OK I think you are on to something here!! in thinking about is some more I have an idea as to what might be going on to exaggerate the low end bass from the mains...

My main speakers are within cabinets. And I know these speakers are not designed to be within an enclosure like some speakers are.

My fronts are Pinnacle Classic Gold Reference speakers. They are towers with a size of 8 3/8" Wide x 33" High x 13 1/4" Deep. Each is within an enclosed cabinet that has GOM fabric in the front. The cabinet is not much larger than the size of the speakers (cabinets are part of the wall unit these speakers sit in).

In particular I'd say that within the cabinet there is about 5-6" of space to the left/right of the speaker, about 6" of space behind the speaker, and about 8" or so above the speaker.

It seems logical that the cabinet enclosure could be having the affect of significantly boosting/amplifying the bass. So whereas before we suspected that the receiver was somehow boosting it - maybe its the enclosure. What do you think?

If it is the enclosure, I certainly cannot move the speakers but perhaps I can treat the inside of that cabinet and this would help? If so what's a good material to treat it with? Right now the inside of the cabinet is just hard wood.

Thanks!

[brucek]

It seems logical that the cabinet enclosure could be having the affect of significantly boosting/amplifying the bass. So whereas before we suspected that the receiver was somehow boosting it - maybe its the enclosure. What do you think?

Yeah, you're not suppose to do that really. The speakers should be out and away from all reflective surfaces by a few feet at least.....

brucek

[lovingdvd]

brucek wrote:

Yeah, you're not suppose to do that really. The speakers should be out and away from all reflective surfaces by a few feet at least.....

brucek

Thanks. Well now that I have the ability to measure actual response, as an experiment I'm going to take the speakers out of the cabinet and put them on a small table, just in front of where they were residing. Then I'll measure the response of the fronts this way vs. how they sound in the cabinet. It will be interesting to see the results.

BTW if anyone knows a good way to soundproof the inside of the cabinet to help cut down on the bass bouncing around in there please let me know (maybe some sort of insulation or something?).

[cyberbri]

Warning: once you take them out of the cabinets and hear how they sound, you won't want to put them back and you'll end up doing whatever you can to keep them out.


In my last residence, we had a wall where the TV went, with the TV stand in the middle and 2 cabinets flanking it with shelves above the TV strapped to the cabinets. I didn't have room to have the speakers out, so my towers were situated in the bottom half of the cabinets. One time I took the speakers out to see how they sounded, and it was almost a night/day difference. I even sat my wife down and she was surprised - she said they sounded bigger and more open. I didn't get to keep them "out," but the next residence we moved to (our current one) has a much bigger room for me to move my speakers and sub around as I see fit.


BTW, you might see about stuffing the cabinet with towels/blankets. And do the speakers have rear ports, firing into the open cavities?

[niget2002]

I'm having this same problem. I'm even considering redoing my entire entertainment center because of it.

[lovingdvd]

cyberbri wrote:

BTW, you might see about stuffing the cabinet with towels/blankets. And do the speakers have rear ports, firing into the open cavities?

Yes, they have ports that fire into the open cavities, although keep in mind that it forms a sealed "box". In other words its not a large cavity but rather a single sealed cabinet that the speaker sits within. Perhaps this makes it even worse (since the frequency has no where to go by out).

[cyberbri]

Yeah, even if it's sealed in the back, the bass will bounce around in there, and make the cabinet itself resonate at different SPLs and frequencies.