One thing to help with integrating a sub that is not super expensive is the (Studio Six Digital) AudioTools App (for phone or tablet) https://www.studiosixdigital.com/audiotools-modules-2/
I have an Audio Control one third octave RTA and can attest that the above (as well as something like Room EQ Wizard) does a great job.
One would get a calibrated mic to use with the phone or tablet such as https://www.parts-express.com/dayton-audio-imm-6-calibrated-measurement-microphone-for-tablets-iphon... The mic comes with an individual calibration file.
Usually what I do is measure from the listening position with the sub off at first to get an idea as to whatever room induced frequency abnormalities are present. The sub should be crossed over just below where the mains start to drop off (in your room). Where I have had my 3.7s and from the other couple of pairs I have seen, it can typically start to drop off in the upper 20s.
As noted, one's room can cause differences in those measurements. If it does start to drop off in the upper 20s, one would want a sub crossover to be just below that. I have my subs (Rel Storm IIIs) crossed over at 22Hz. From my listening position, the bass is near flat from 25Hz and up.
The crossovers with many subs are usually not great. Many of the subs are designed with HT in mind, where one would set the crossover high and use the crossover in the receiver or HT processor. Once one measures without the subs, I typically (and that includes many systems I've calibrated for others) set their HT sub (and I have a friend with an SVS sub that somone told him to buy, which he uses with a pair of Ohm 2000s and eventually he'll replace that sub as the low crossover point is 50Hz) at the minimum crossover point.
When I use AudioTools with the RTA, I take a screen shot of the measurement without the sub. After setting the crossover at or around the lowest point (depending on the speakers involved), I'll use the subs volume control to achieve what is a better measurement with the sub active. With many HT subs, as noted above, you won't get as good a result vs. using something like a Rel or Thiel sub which are designed more for music use. My friend does nice woodwork and has a friend who designs commerical systems and at some point (an amp is next up in his system) he'll build something better that his current sub.
I have an Audio Control one third octave RTA and can attest that the above (as well as something like Room EQ Wizard) does a great job.
One would get a calibrated mic to use with the phone or tablet such as https://www.parts-express.com/dayton-audio-imm-6-calibrated-measurement-microphone-for-tablets-iphon... The mic comes with an individual calibration file.
Usually what I do is measure from the listening position with the sub off at first to get an idea as to whatever room induced frequency abnormalities are present. The sub should be crossed over just below where the mains start to drop off (in your room). Where I have had my 3.7s and from the other couple of pairs I have seen, it can typically start to drop off in the upper 20s.
As noted, one's room can cause differences in those measurements. If it does start to drop off in the upper 20s, one would want a sub crossover to be just below that. I have my subs (Rel Storm IIIs) crossed over at 22Hz. From my listening position, the bass is near flat from 25Hz and up.
The crossovers with many subs are usually not great. Many of the subs are designed with HT in mind, where one would set the crossover high and use the crossover in the receiver or HT processor. Once one measures without the subs, I typically (and that includes many systems I've calibrated for others) set their HT sub (and I have a friend with an SVS sub that somone told him to buy, which he uses with a pair of Ohm 2000s and eventually he'll replace that sub as the low crossover point is 50Hz) at the minimum crossover point.
When I use AudioTools with the RTA, I take a screen shot of the measurement without the sub. After setting the crossover at or around the lowest point (depending on the speakers involved), I'll use the subs volume control to achieve what is a better measurement with the sub active. With many HT subs, as noted above, you won't get as good a result vs. using something like a Rel or Thiel sub which are designed more for music use. My friend does nice woodwork and has a friend who designs commerical systems and at some point (an amp is next up in his system) he'll build something better that his current sub.
