Crossover experiment - advice needed

azsam

Hi guys,

I have been debating what would be the best crossover setting on my setup in a real life listening as opposed to on paper and looking at speaker specs. I am intentionally not mentioning the model of speakers I have.

I basically got some stereo test tones in flac and used a phone app as SPL meter - I know this is not how it is supposed to be done but those are relative measures - same positioning of the phone, same loudness of avr, etc.

Room noise level was measured at 31 db (when nothing was playing)
AVR was turned up to 50 (my normal listening volume)
Since those were stereo files only my front left, right, and sub were engaged

I have a 5.1 setup and movie watching is more important that music. I just want to make sure I choose the right Xover setting.

I am attaching an excel spreadsheet of my results. Based on the numbers that you see, what can you tell me? What should be my crossover setting and why?

tonyb

azsam wrote: »

I have been debating what would be the best crossover setting on my setup in a real life listening as opposed to on paper and looking at speaker specs. I am intentionally not mentioning the model of speakers I have.

"..as opposed to on paper and speaker specs" ? Isn't that what your asking people to do ? LOL

without the additional info, this exercise is useless imho.

azsam

tonyb wrote: »

"..as opposed to on paper and speaker specs" ? Isn't that what your asking people to do ? LOL

without the additional info, this exercise is useless imho.

OK, was just trying to avoid bias. Here is the info:

Subwoofer: SVS PB-1000

Fronts: Polk Monitor Series II 40 with Lower -3dB Limit rated as 57 Hz
Center: Polk Monitor Series II CS1 with Lower -3dB Limit rated as 65 Hz
Surrounds: Polk Monitor Series II 30 with Lower -3dB Limit rated as 63 Hz

azsam

I also did another test. I turned off the sub, set the mains Monitor 40s to large and ran the sound files. Surprisingly I got response even in the 16Hz :O If we look at this test what can be concluded as the best crossover for the fronts?

aboroth00

Usually the SPL meter on a phone isn't as sensitive to the lowest frequencies i.e. <100hz. Usually all mics need calibration files to boost response in this area for the mic to accurately measure this region. If you're interested in optimizing your setup thoroughly, i'd highly recommend you get a mic ~100$ and REW which is free.

In room response, will bump all the F3 a little lower, (give your speaker better extension), but in a HT environment you want your sub to handle the midbass frequencies, 60-100hz. I would recommend you not set your XO lower than 60hz or higher than 80hz because of localizability. Once you have this set, you can play around with things such as EQ to really get the most out of your system.

aboroth00

Here's some graphs of my room and speakers to give you a point of reference. My preference is for music so I have my sub coming in earlier. If I did HT, i'd set the sub to 80hz and deal with the peak at 80hz with EQ.

http://www.polkaudio.com/forums/showthread.php?158098-Polk-LSI15-Should-I-again&p=2012009&viewfull=1#post2012009

azsam

OK, I will give up on the idea of finding the best setting and will just set at 80Hz

azsam

Sorry guys but this still bothers me. I re-calibrated with Audissey, just to see if that will change anything. So, Audissey detected crossover frequency for all speakers to be 40Hz, and set my Monitor40s as Large (I changed to small manually). I also overwrote the crossover to 80Hz as suggested. I don't know why, but the bass seems boomy. I know the SVS PB-1000 has a flat response throughout its range so it cannot be from it. I set the crossover to 100Hz and now my front stage sounds crispier. There is still lots of punch in the bass. When I play a movie my sofa still shakes. On the other hand the front stage is so clearer that I kind of even have to turn the volume down a bit.

My receiver also allows me to set the cross over to 90Hz which I tried and it is kind of like middle ground between the boominess at 80Hz and the clarity of 100Hz. Is there a chance that the Monitor 40s produce boomy bass around 80 Hz (i.e. at standard crossover point)? Maybe my small room has an effect on that (16.5 x 13 x 8.5 feet)?