New Sub...2nd try at REW

I finally go my new sub....a HSU STF2. Its really my first "real" sub as the one I had before was an el-cheap 8" Sony.

I had posted a few weeks ago with some plots I did witht he old sub.

After hooking my new HSU up....I played around with REW and trying it out in 2 possible locations I can put in in my room.

Does it look like I am doing things correctly?

I am still learning what all this is telling me. I assume the 2nd plot(loc #2) is the better?

Location #1 in back Corner


Location #2 side near front right speaker.

[brucek]

No, I would say location #2 is poor with respect to extension. You have lots of low end extension in #1 . You also have a couple peaks that can be equalized away, and then the wholesale gain increased.

Is the graph through your receiver with the mains off and the crossover engaged?

brucek

brucek wrote:

No, I would say location #2 is poor with respect to extension. You have lots of low end extension in #1 . You also have a couple peaks that can be equalized away, and then the wholesale gain increased.

Is the graph through your receiver with the mains off and the crossover engaged?

brucek

Those are through my receiver (H/K 247), with the mains(Klipsch KSF 10.5) on and the XO engaged at 80.

I need to redo the measurements with the mains off?.

But I think I understand what you are saying with regards to the low-end extension.. I guess my brain was thinking that less dips/peaks is best.

[brucek]

I need to redo the measurements with the mains off?.

If you plan to equalize the sub, it's advisable to disconnect the mains and do a sub only measure first to see how it contributes by itself. Once the best position is found and then the sub equalized, you add the mains and see how the sub and mains integrate. The phase of the sub usually requires adjustment at that time to make the crossover transition smooth.

brucek.

brucek wrote:

If you plan to equalize the sub, it's advisable to disconnect the mains and do a sub only measure first to see how it contributes by itself. Once the best position is found and then the sub equalized, you add the mains and see how the sub and mains integrate. The phase of the sub usually requires adjustment at that time to make the crossover transition smooth.

brucek.

Thanks for the info.

The boss is about to get home so I need to put away all the wires, PC in the middle of the room, tripods and such =P but will get back to taking proper measurements tomorrow.

[JohnM]

The extra low end in location 1 looks to be excitation of a couple of primary modal resonances. I'd be tempted by location 2, favouring a more uniform response over some output at the very lowest frequencies. Location 1 would probably be improved by some crossover phase adjustment though.

[mojogoes]

Not to highjack this thread....i would just like to ask if it were better to have both sub and main speakers connected to take some readings...or like i have done just the sub connected through the bfd set at bypass via s/b card and preamp and ecm8000....so that i'm only taking readings of the sub.

Can i then include the main speakers with my spl meter only for integration after the sub id eq'd.

JohnM wrote:

The extra low end in location 1 looks to be excitation of a couple of primary modal resonances. I'd be tempted by location 2, favouring a more uniform response over some output at the very lowest frequencies. Location 1 would probably be improved by some crossover phase adjustment though.

Hopefully I will be able to do more measurements when I get home from work today.

Going on my ear alone...the sub in loc #2 sounds/feels less "localized" than in loc #2

I want to do 4 measurements....both locations with 180phase and 0phase.

Something that has me concerned is that I can run a measurement multiple times in a row without moving anything or changing any settings and get different plots...some of which differ quite abit. So I am not sure if I have something setup wrong or if the results I am getting can be trusted.

Here is a rough foreplan of my room/apartment. I am just not sure if its even possible to get a good plot in this room....

[brucek]

i would just like to ask if it were better to have both sub and main speakers connected to take some readings

Yes, after you take a sub only reading with the mains disconnected. You want to have the sub tested through the receiver so that the standard crossover is in place that you use.

brucek

OK decided to start over from scratch...replaced some of the adapters cables I was using cause one of them was flacky. Reset REW and redid the calibrations for soundcard and mic/SPL.

Getting more consistent results...did 4 measurements....both locations @ 180 and 0 phase.

So it seems now that I have REW configred correctly and am getting consistent results...the results are not as nice =P

Location #2: Blue = Phase @ 0, Orange = Phase @ 180



Location #1: Purple = Phase @ 0, Aqua = Phase @ 180




Well not sure what this is really telling me....My room sucks? =P

Phase @ 180 seems the better at both locations?

Although my SPL and REW are calibrated...@75db...everythings seems high?

Really confused.