Axiom Home Page Forums General Discussion Technical Questions My REW readings

Ok I finally took some time to play with REW and this was the results of my current positioning.

A full spectrum reading


I jacked up the XO to 250 to eliminate the mains as best as possible.

sub in 20hz tune


15hz tune


10hz tune


sub ports sealed


and finally all the sub readings super imposed

Now here are some pics with a 40hz XO

20hz normal tune


15hz tune


10hz tune


Sealed


all superimposed


and a quick comparison with 40hz and 250 hz sub sealed

Where did you set the crossover? At the sub?

I'm going to mess around with my room some more around the first of the year, so I am just soaking up everyone else's experiences and experiments.

I'm going to have to read a bit on that software.

God help me, I might see if I can tweak things after I set up the receiver! I'm heading down a dark path........

Yeah, I keep being about to set it up and then I realize I don't have the material it needs... and I then forget to gather it!

In the receiver.

I did some more testing with speakers set to small and the 20, 40, 60, 80hz XO's, and I get the best, smoothest response with small speaker setting and 60hz crossover sub in a 15 hz tune, which is where I thought it sounded the best without knowing any of this graphing. It isn't much different than what is above. It just goes to show you can trust your ears, to a certain extent.

Now to play around with the RTA software to see if it comes up with different readings and then more full spectrum graphing with 5.1

Your room looks pretty good below 100Hz Jay. Did you do any measurements at other seating positions?

No just the main seating position. Now that I have a reasonable idea of how to run the program and what to look for etc. I am planning on running it at the other main seating position as well.

I now want to get a USB sound card to use my wife's laptop instead of my older and noisy XP box. Either tha or I have to invest in a quieter P/S for it.

Oooh, I can help with that! A power supply might be cheaper than a quality USB sound card.

You would be looking at between $45 and $75 depending on what you want. Seasonic makes the largest range of quiet power supplies. The S12II 380 or 430 are top quality supplies and are dead silent. I bought the Corsair OEM version last year (it was cheapest at the time) and it is dead silent, even by silent PC standards.

If you want something cheaper and not quite dead silent, you could look at the Seasonic SS300/400E? (dang, can't remember the last character) at around $40-45. The other option in this range is the FSB300/350/400 that are in the same range. You can find links to both of these psu's here.

Dead Silent would be a good name for a band.

The sound cards are about the same price, but it would be nice to keep using this PC for other purposes, it is actually a pretty good PC, 2 gigram, 2 SATA 80 HDD's Gigabyte K7N, it works great just a very noisy PC.

Thanks for the info Fred.

Or Mute Corpse.

A band of mimes.

Jay - I'm sure I'm reading this wrong... but does the graph go down to 2 hz? If so... 90 dB at 2 Hz, you're liable to scramble your innards...

What am I reading wrong?

2 more questions:

What dB level were you calibrating to?

What is the peak point between 10 and 20 Hz? (it's visible in the 10,15, and sealed graphs). Guessing it's 15 Hz? Looks like very good response that low. Love the PB13.

Jason

I set the scale down to 2, I have no idea if that is a true reading or not. The system was calibrated to 75db, so I am a little hot on my bass, but realtively smooth, which I can handle. IIRC, that peak is 16-17 depending on which tune the sub was in. I guess this is what I feel so much of during movies.

Thats not accurate. The ratshack meter (with correction file) is accurate down to about 20hz. Once you get to 10Hz, the readings are probably meaningless.

Well good, I'd hate to think Jay had done permanent damage to his internal organs with those kind of sound waves.

In the other hand, maybe he inherited Iron Man's guts.