Freq Response for My SVS

[moreira85]

I just plotted the Freq respsonse for my SVS and it was actually fun.
I hope i did it right. I used the freq from real traps and measured from 20 to 100hz. when i put in the cd i just let it play and recorded the resonses on a spread sheet and did my own graph. Any advice on how to interpret or any action steps? Also when i put the CD in I just let it play i didnt turn off all the speakers and just leave the sub on, is this okay?
check it out.

I am having trouble attaching an excel file, how can i do that?

 

[Adam]

To show us the plot, here's my suggestion. Select the chart in Excel, copy it, open Paint (I'm assuming that you're using Windows), and paste it. You can then save the plot as an image file that you can attach here (or upload to Photobucket or Flickr and then link here).

 

[moreira85]

To show us the plot, here's my suggestion. Select the chart in Excel, copy it, open Paint (I'm assuming that you're using Windows), and paste it. You can then save the plot as an image file that you can attach here (or upload to Photobucket or Flickr and then link here).

what is paint? forget it i i found it.

 

[Adam]

what is paint?

If you are using Windows, then Paint is one of the accessories that comes with the operating system. You can find it under the Start Menu - Programs - Accessories.

 

[moreira85]

Ah Hah

here it is, suggestions?

 

[fredk]

I just plotted the Freq respsonse for my SVS and it was actually fun.
I hope i did it right. I used the freq from real traps and measured from 20 to 100hz. when i put in the cd i just let it play and recorded the resonses on a spread sheet and did my own graph. Any advice on how to interpret or any action steps? Also when i put the CD in I just let it play i didnt turn off all the speakers and just leave the sub on, is this okay?
check it out.

I am having trouble attaching an excel file, how can i do that?

If you think that was fun and you have a computer and a few extra cables, you should try this program. It will keep you entertained for days!

There is nothing wrong with measuring the whole system to see what your bass response is. The down side is that you have more to sort through to figure out how to improve your bass response.

If you measure the sub only first and match it against a low-pass curve you can first set up your sub properly and then play with the rest of the system to optimize the bass response.

Looking at your plot, the sub seems to do very well below 60Hz and looks to be well positioned in the room. Ideally you want a flat line across the whole spectrum, but you are currently missing up to 10db (thats a lot) in the 70-110 frequency range. Thats the range that gives you the bass slam/punch.

Looks like you are off to a good start. From here you could play with your crossover frequency (if its not limited to 80Hz) and positioning of the mains and/or sub to see if you can get any improvement in the above mentioned range.

P.S. whats the guitar in your avatar pic?

 

[moreira85]

If you think that was fun and you have a computer and a few extra cables, you should try this program. It will keep you entertained for days!

There is nothing wrong with measuring the whole system to see what your bass response is. The down side is that you have more to sort through to figure out how to improve your bass response.

If you measure the sub only first and match it against a low-pass curve you can first set up your sub properly and then play with the rest of the system to optimize the bass response.

Looking at your plot, the sub seems to do very well below 60Hz and looks to be well positioned in the room. Ideally you want a flat line across the whole spectrum, but you are currently missing up to 10db (thats a lot) in the 70-110 frequency range. Thats the range that gives you the bass slam/punch.

Looks like you are off to a good start. From here you could play with your crossover frequency (if its not limited to 80Hz) and positioning of the mains and/or sub to see if you can get any improvement in the above mentioned range.

P.S. whats the guitar in your avatar pic?

the guitar is just an avatar i pulled off the net. I have it as an avatar because I play acoustic guitar. i have a takamine.
On another note how can i improve the response above the 60Hz range? I have the crossover set at 80 at present.

 

[djreef]

here it is, suggestions?

Wow, your room charts almost identical to mine, with a 12dB suckout right around 70Hz. I was thinking of adding a second SB-12plus in a different location to kind of flatten it out.

DJ

 

[mike c]

try to solve the suckout by changing the phase

 

[moreira85]

try to solve the suckout by changing the phase

thanks for the tip, I will try adjusting the phase during halftime of the ohio state game and re-do the test.
should i keep the Xover at 80 Hz?
every time i make an adjustment I have to do the whole test all over again?

 

[moreira85]

Reverse phase results

here are both tests. Normal and then with the phase in reverse which is the test attached on the right.
Looks like the reverse phase doesnt drop off as much, think I should leave it in reversed? Both tests were done with crossover set at 80Hz. Should I try to play with the crossover to see if I can improve this even more?

 

[Adam]

That second chart looks much better to me. I'd say leave the phase reversed!

 

[moreira85]

thanks adam. i am going to leave it in reverse, I also just tried crossing at 100Hz instead. I didnt plot it on the graph but will do that tomorrow. I just let it play for awhile and the meter didnt drop as much between freq of 60 and 90 when crossed at 100. I will have to plot it again tomorrow at 100hz and mess around with differ crossover settings.

 

[Adam]

Cool. I look forward to seeing it!

How long does each test tone play? I ask because you mentioned that you just let the disc play. With my SVS, it recommends letting the woofer cool down for ten seconds in between each test tone. I don't know if that's actually necessary, but I do it anyway.

 

[moreira85]

20 to 29 hz plays each test tone for 10 seconds. When it goes to 30 there is a 2 sec break then again 30 to 39 10 seconds per tone.

 

[STRONGBADF1]

thanks adam. i am going to leave it in reverse, I also just tried crossing at 100Hz instead. I didnt plot it on the graph but will do that tomorrow. I just let it play for awhile and the meter didnt drop as much between freq of 60 and 90 when crossed at 100. I will have to plot it again tomorrow at 100hz and mess around with differ crossover settings.

Watch going too high with the crossover. The sub could get localized.

Just out of curiosity...Is the sub in 25, 20 or 16htz tune?

 

[moreira85]

Watch going too high with the crossover. The sub could get localized.

Just out of curiosity...Is the sub in 25, 20 or 16htz tune?

its in 25 hz tuning. I know i dont want to put the crossover to high, i was hesitant about 100. i am going to try the test at 40, 60, 80, 90 100hz and then pick the flatest one. any other tips for trying to flatten it out? the reveiver has a auto peq, center geq, or eq off, should i try that or just leave it in auto eq.

 

[STRONGBADF1]

its in 25 hz tuning. I know i dont want to put the crossover to high, i was hesitant about 100. i am going to try the test at 40, 60, 80, 90 100hz and then pick the flatest one. any other tips for trying to flatten it out? the reveiver has a auto peq, center geq, or eq off, should i try that or just leave it in auto eq.

Do you have any EQ turned on? Your sub has a one band PEQ correct? EQ should be the last step. Positioning first (with the XO & phase set to a baseline...say 80 & 0) then phase then crossover then room treatments then EQ. (in a perfect world)

Why 25htz tuning? Like I said just curious. I have the new PB12 plus and just like to here how others set up their subs and why.

I've been lazy and need to measure my room still but I'm going to start with the EQ off (both sub and receiver), XO @ 80htz and the sub in its natural 20htz tune as a baseline. After that the readings will dictate what is next. I have limited placement options in my current room so it could be pretty ugly... I do have another room to try though.

 

[lsiberian]

Watch going too high with the crossover. The sub could get localized.

Just out of curiosity...Is the sub in 25, 20 or 16htz tune?

I've found localization has more to do with placement than crossover In my experience. 100hz was less localize-able for me actually. It's a strange mystery, but rooms are wierd things.

 

[moreira85]

Do you have any EQ turned on? Your sub has a one band PEQ correct? EQ should be the last step. Positioning first (with the XO & phase set to a baseline...say 80 & 0) then phase then crossover then room treatments then EQ. (in a perfect world)
Why 25htz tuning? Like I said just curious. I have the new PB12 plus and just like to here how others set up their subs and why.
I've been lazy and need to measure my room still but I'm going to start with the EQ off (both sub and receiver), XO @ 80htz and the sub in its natural 20htz tune as a baseline. After that the readings will dictate what is next. I have limited placement options in my current room so it could be pretty ugly... I do have another room to try though.

No i dont have a PEQ on the SVS PB12 +2. I called them when I got it and they said that the one that comes in black ash finish does not come with it. i have the EQ on the receiver set to auto. Crossover is turned off on the sub and X at 100Hz on the receiver Xover and phase is reversed. if you look pack at previous post you will see reverse had less of a dip.
I have mine in tuned to 25 Hz because large room 24x16 with vaulted ceilings and I believe 25Hz gives more output.