Lack of bass in NHT 3.3.

Thanks again onwhy. The omnimic shows a nice flat frequency response down to 20 Hz. My question is more about the spl levels I should expect from this 12 inch sealed subwoofer, as I have stated it seems to be about the same as my Martin Logan Grotto subwoofer, nice low frequencies but not a lot of SPL.

Onwhy, sorry if I did not read your instructions carefully. When you say strong down to 30 Hz I am guessing that this frequency area should have the same db reading. Will check it out if I can find an appropriate cd with the requisite tones. Thanks, LS

Onwhy I have run the test to the best of my ability and with the following info. Found an old mmg test cd(ultimate test cd). It starts with a 0 db test tone at 1khz and then offers tones at -10db of 20,30,40,50,60,100,..... Hz. The room the speakers are in, which does not offer optimal placement, though when they were auditioned at the buyers home they did have optimal placement, currently has a non weighted ambient noise level of  about 70 db. Ran the test tone at about 100 db and then ran the first few low tones. The Spl levels were pretty negligible till it got to 50 Hz. If the tests were done properly and if this result is not what the speakers were designed to produce, discounting the room and gear they are currently hooked up to, since there is no evidence of damage externally to the cones and since I have been told that crossovers should not be a problem, since both would have to fail and that the signal flows thru chokes which are not likely to fail. What other possibilities are there. I am guessing if they were both damaged i would hear some distortion and not merely a lack of volume. Sure hope there is an Agon member that currently has a pair that can weigh in. Thanks for your input, LS

For grins I ran the same test in my listening room which seems to have the same level of ambient noise and got slightly superior results. About what I expected, my martin logan sub is putting out a little bit more spl than the built in nht subs. Are the nhts defective for putting out low spls and if so what is the cause. If they are running as designed , then do I conclude the would be buyers 17 year old memory is defective. Any current 3.3 pwners out there that can weigh in? Thanks, LS

I’m a 2.9 owner. The mid bass coupler and the subwoofer are room dependent. You have to have the speakers at least 7 feet apart with no furniture too close to the side firing subs.They also need to be close to the back wall and about 22" from side walls which I have mine and they sound good. If you have a TV between the speakers or furniture blocking the side firing subs the woofers are not loading properly and you might be getting cancellation of bass frequencies. Push the TV as close to the wall as possible so it don’t create a 2nd wall near the front of the speaker baffles or side subs. Get a CD that has lots of bass and play the music loud for days. Your woofers both the subs and bass coupler might not be broken in all of the way. The two pairs of connectors on the back try connecting the wires to the bottom set which is direct to the subs first in the circuit. Might be a phase problem. Make sure both the top and bottom connectors are tight, even the ones that have no wires attached to them. Try bi-wiring too. Not bi-amping but bi-wiring. Make sure the wiring is not out of phase. Check to make sure someone didn't wire the woofers out of phase to compensate for a center channel speaker not meant for these speakers. These speakers need to be tuned to your room and system like a fine instrument.