new VTF1 - doesn't sound right

[tv10]

Recently bought a new VTF1 this pass xmas. When I got it, I tried a few music cd and it just didn't sound right (not at all tight and boomy when i turn up the vol). I figure maybe room acoustic problem or setup or placement but haven't really had the time to play with it.

Yesterday I tried again and it sound the same. I tried moving the sub to various location, tried the crawl on the floor method and it's the same. So I took the following measurement with an SPL meter.

Disclosure - my first time playing with sub so I'm a novice... Not sure if I'm doing this correctly so any advice is welcome.

My setup:
- VTF1 connected to Harmon Kardon AVR75 (yes, very old receiver, but it was just a test) sub preamp output.
- No other speakers connected
- Crossover at the sub set to 60Hz and IN
- Volume on sub set to 9am position
- Volume on receiver set to -10
- SPL meter is ~ 6" from the Sub
- Measured with HSU BAS/CD (track 11-20 or 25 to 200Hz)

With 2 port open (32Hz), my readings are:
25Hz - 60dB
31.5 - 66-70
40 - 76
50 - 79
63 - 80
80 - 80
100 - 77
125 - 72
160 - 56
200 - 43

With 1 port open (25Hz), my readings are:
25Hz - 62
31.5 - 72
40 - 76
50 - 78
63 - 79
80 - 78
100 - 77
125 - 72
160 - 58
200 - 43

Seems strange that 63Hz to 100Hz is still pretty loud??? Do these readings mean anything? Advice on what I should do to narrow down the problem?

[Pete_Hsu]

tv10, may I see measurements between 25-200Hz with the main speakers and subwoofer both ON?

Does your H/K receiver have bass management (ie. does it let you set crossover frequency for speakers/sub, distance settings, channel level, etc)?

Thanks

Sincerely,

[tv10]

Thanks for the quick response Pete. I will take measurements with the main speaker on using the same setup.

I'm actually not sure if the HK AVR75 have bass management... will check. I also have an Onkyo that I know does (sub crossover, distance, level). Any particular settings on the receiver you want me to try?

[Pete_Hsu]

Hi tv10,

Make sure to set all speakers to 'Small' on the receiver, start with 80Hz crossover all around, set distance settings appropriate (= distance between main listening position and each speaker and subwoofer), and finally you can start with channel level at +0db for all channels.

Take one set of measurements with main speakers and subwoofer on with the sub amp at 0 degrees phase, and then try inverting the phase to 180 on the sub amp and redo the measurements.

Thanks

Sincerely,