2nd time around..measurements

[Wayne A. Pflughaupt]

Mattlock wrote:

Wayne....got a semi-random question for you. Does it make any sense for me to consider a 2nd sub up front if indeed I cannot get the peak/dip range shortened?

It may make things worse. You could do some checking using the SVS before you sell it, but don’t forget to level-match them first.

I may be able to put the sub up front left next to picture...it's already wired. Challenge is I have my front speaker there as well. It may mean I have to reduce my screen little due to the diameter of this beast....see picture.

Maybe you could lay it on its side? You’d have to do something to keep it from rolling, of course. And make some kind of custom stand or wall mount for the left speaker...

Your before and after graph, does the “after” sound any better?

Regards,
Wayne

[Mattlock]

Wayne A. Pflughaupt wrote:

It may make things worse. You could do some checking using the SVS before you sell it, but don’t forget to level-match them first.


Maybe you could lay it on its side? You’d have to do something to keep it from rolling, of course. And make some kind of custom stand or wall mount for the left speaker...

Your before and after graph, does the “after” sound any better?

Regards,
Wayne

Havent really had time to do much comparison yet but will soon. These holiday plans just get in the way of more important things..

[JohnM]

From the impulse response the distortion looks very high, getting on for 10% 2nd harmonic and several % 3rd harmonic. May want to check the sub isn't being driven too hard.

[Mattlock]

JohnM wrote:

From the impulse response the distortion looks very high, getting on for 10% 2nd harmonic and several % 3rd harmonic. May want to check the sub isn't being driven too hard.

John, what exactly would i be looking at or changing to reduce the sub strain?

thanks

[JohnM]

Just lower volume - was the sub playing particualrly loud when generating that impulse response? Otherwise might just be the nature of the drive unit.

[Mattlock]

JohnM wrote:

Just lower volume - was the sub playing particualrly loud when generating that impulse response? Otherwise might just be the nature of the drive unit.

Actually it wasnt playing that loud. Another thought....could it be possible leakage around the top and bottom endcaps? I havent sealed it yet but to be honest they are very tight anyway..had to hammer down.... Another thought...my doors in my room rattle pretty loudly but this is probably a higher hz anyway....

thanks John for the thoughts
Matt

[Mattlock]

Here's my latest curve.....even though I tried different gains from 3 to 8 I really couldnt get much movement on the 49hz dip....

Question: I realize gains have to be used with caution but at what point (ie amount) is the gain considered "pushing the boundary of reasonableness"?

thanks
Matt

[MakeFlat]

Mattlock wrote:

Here's my latest curve.....even though I tried different gains from 3 to 8 I really couldnt get much movement on the 49hz dip....

Question: I realize gains have to be used with caution but at what point (ie amount) is the gain considered "pushing the boundary of reasonableness"?

thanks
Matt

That depends on the sub's power.

You can push the gain as long as you have the headroom. For the sake of explanation, let's just say that you have 6 dB headroom for the sub, like your loudest movie is 6dB below the power reserve of the sub. Then you can push 3dB and still maintain a 3dB headroom for the sub, just in case you happen to crank the avr volume control a little higher than normal.

A little boost is not going to cause an issue. If however, the boost does practically nothing, you may as well not apply the boost. That 49Hz dip is likely much deeper than visible on the graph, so it's not going to budge. The value of adding 6dB to a 16dB dip is questionable.

[Jman]

Mattlock wrote:

Here's my latest curve.....even though I tried different gains from 3 to 8 I really couldnt get much movement on the 49hz dip....

Question: I realize gains have to be used with caution but at what point (ie amount) is the gain considered "pushing the boundary of reasonableness"?

thanks
Matt

Earlier I asked if you had room for bass traps. They'll reduce those deep/narrow nodes that you're getting. The problem with trying to fix deep notches with EQ is that it usually does little or nothing. That's the nature of room nodes. The traps reduce the room interaction, which are what cause them in the first place.

The front left and right corners would be a great place for 2 traps. Is that door at the front right used? You could also put one at the back where the sonosub is. The traps would need to be 2' wide and mounted at 45 degree angle at 2 boundaries like 2 walls, wall/ceiling, wall/floor.

[DrWho]

It also looks like your sub is tuned too low, and the ports aren't being loaded fully. It's hard to tell from the pics, but the measurements indicate that the sub is about 6 feet tall? (on the inside) What's the internals of the sub look like?

Also, is your mic moving inbetween measurements? If you think about it, it doesn't make sense for your dips to move around in frequency (unless of course you move the mic around).