Heeman - WI Basement HT Build

[Flint]

I have a significant null at 80 and 90 Hz, the rest of the low end is pretty even.

I will try moving one of the subs next weekend.

So far, it is great!

Remind me of the depth of the room?

 

[heeman]

4.5 in 5.1.....,,,,

It sounds so freakin' good!

 

[heeman]

Remind me of the depth of the room?

I think I figured it out.

 

[heeman]

Remind me of the depth of the room?

16' 3"

 

[Flint]

16' 2" = 70Hz

80 Hz = 14.1 feet / 7.05 feet (21.15 feet / 29.2 feet)
90 Hz = 12.5 feet / 6.25 feet (18.75 feet / 25 feet)

 

[heeman]

So this can't be eliminate?

 

[Flint]

Controlled, but not eliminated.

 

[heeman]

I know that this type of testing is not optimal, however it helped me tune the TX HT.

I play tones from 20 - 90Hz in 10 Hz increments and measure with the SPL Meter.

I make these measurements at various distance settings.

The optimal has been at 13'

20 - 80
30 - 81.4
40 - 83.9
50 - 83.3
60 - 87.6
70 - 85.5
80 - 76.6
90 - 79.0

 

[Zing]

^Have you also experimented with different crossover points? I dramatically reduced a null I had by setting the XO to 90Hz from 80Hz.

 

[Flint]

That's not too bad for long term test tones. Tones like that enhance the resonance. Can you perform a quick sweep?

 

[Flint]

Also, if 90 hz is a real standing wave null, testing 45hz should show either a null or node. You could also test 135hz to understand 90 hz better.

 

[heeman]

That's not too bad for long term test tones. Tones like that enhance the resonance. Can you perform a quick sweep?

No.

 

[heeman]

Also, if 90 hz is a real standing wave null, testing 45hz should show either a null or node. You could also test 135hz to understand 90 hz better.

Will try this next weekend.

 

[heeman]

^Have you also experimented with different crossover points? I dramatically reduced a null I had by setting the XO to 90Hz from 80Hz.

Will try this next weekend!

 

[heeman]

OK................so I could not wait!!!

Measure in 1Hz increment from 70 - 99.

70 - 98.8 Drops almost 1 dB/ 1 Hz
80 - 91.5 Creeps up ever slowly to 94.1 @ 89 Hz
90 - 99 varies from 94.3 - 95.1

So we lose 7.5 dB from 70 to 80 Hz.

I also measured from 40 - 49 Hz pretty solid in the low to mid 96 dB range

 

[heeman]

 

[heeman]

 

[Deleted member 133]

View attachment 6689

Stunning!

Attaboy Keith (and Barb)!

Jeff

 

[Batman]

Looks really great Heeman!!

 

[Flint]

View attachment 6688

Actually, that's a surprisingly smooth graph.