Bry_DD's graph - SVS 25-31 CS - Let him know if it looks OK (1 Viewer)

[felix_suwarno]

he said this on his original post :
hi all! maybe someone can help me out. I did a graph on my svs25-31cs and I would like to show it to all and tell me if it looks ok.
Link Removed

 

[Bry_DD]

thanks felix

 

[Bry_DD]

Anyone?

 

[brucek]

Bry_DD,

You're going to have to give us a bit more information.

Is this a "sub only" graph or is it taken with your mains on?

Is this through your processor with speakers set to small and what is your crossover frequency?

Did you take your readings from your normal listening position?

What is your room like?

Where is the sub located, i.e front corner loaded?

Are you considering an EQ or are you trying to smooth the response by location?

Not really necessary, but you took a rather high set of readings, maybe it would be better at around 85dB to 95dB.....

brucek

 

[Bry_DD]

sub only front corner loaded. room size is about 20x18 open to another room. just trying to smooth out by location.

thanks for any input,

bry

 

[brucek]

Bry_DD,

If you cross at 80Hz you don't have to be too concerned above that area, but you have a couple peaks at 63Hz and 40Hz that you need to reduce.

These peaks are determining your sub level for you. If you could reduce them by equalizing (easy) or location (unlikely), then your bass would sound much smoother and more even.

brucek

 

[Tom Vodhanel]

Bry,

Sorry I missed this the first time...we just can't build the PCi subs fast enough...so things are a bit hectic right now...

Did you take the SPL measurements with a Radio Shack meter? If so, did you already appply the compensation to the meter's readings?

TV

 

[Bry_DD]

Hey Tom,

No need to apologize, I know you guys are busy. Anyway,

I took the measurements with the anolog RS meter and also all the numbers has the conpensation to the meter. What actually do I wanna see with the graph or numbers? Even? Thanks for the help Tom.

Bry

 

[SVS-Ron]

Bry/Felix,
The compensation figures Tom mentioned are critical to accurate measurements or charting. On the off chance you have not run into this before take a look here for a brief discussion and some basic numbers you must apply.
It may turn out that use of an inexpensive equalizer will help flatten response (taming peaks is easy, bumping up "depressions" is not), but it's best to have the full picture before anyone spends another dime in this arena.
Ron

 

[Tom Vodhanel]

Bry,

Which amp are you using? Would you have time to redo the graphs.

1)using 1-2 other mic positions?(assuming you have at least 2-3 *key* seats in the room)

2)experimenting a bit with subwoofer location?(you can hold off on this one if you can try 1 and 3)

3)using an output level that peaks in the 80-85dB range on the chart?

TV

 

[Bry_DD]

hey Tom,
I'm going to do another measurements and I'll just post them again. btw i'm using a plate amp that I took from my HK sub ... I think it's about 80 or 60w. don't remember. At first I was using my old DPL (Kenwood) but it kept on going to safe mode. I'm sure you know why.:b But when I tried the plate amp I can crank it up with no problem at all and it has more punch in it.. I'll eventually replace it with a better amp though.
Thanks for the help,
Bry

 

[Mark Seaton]

I'm going to do another measurements and I'll just post them again. btw i'm using a plate amp that I took from my HK sub ... I think it's about 80 or 60w.

Looks like we've found the culprit for the lack of bottom end. It is very likely the HK sub had a high pass filter in it to protect its driver. In this case, it appears that filter is somewhere in the mid 30s. Looks like it's time to check out the plate amps at Parts Express or find a cheap, used amplifier. Changing the amplifier should bolster the low end, and then you can focus on moving things around to tame the peaks and dips seen in the upper octaves.

Regards,

 

[Tom Vodhanel]

Mark nailed it,

Try a different amp asap...even an old 2 channel receiver might work better for you.

Once you check a couple of different seats, we'll know for sure if it is a problem with the amps bottom end rolloff(likely).

TV