Axiom Home Page Forums General Discussion Advice from Axiom Owners SPL meter

Got it! Very nice little thing. It was great to finally be able to run the Avia disk to double-check my sub settings. I only had three little changes to do, but they made the bass smoother (a slightly higher volume, and setting back TRIM=HALF and flipping phase back to 180 as I had set them by hear until I doubted myself and reset them to NONE and 0). I had two disks that I found had "strange bass". Bass is now good all over the place.

I was also very impressed by the bass transition between all the Axiom speakers and the EP-500. While all these weird noises (going from 150hz down to 20) on the Avia disks were going down, I kept watching the meter and it dipped around 50-60 hz until I changed the TRIM=HALF, and then it was impressively stable all the way; and for all the speakers M80, VP150, QS8. I could never tell when they were really crossing (receiver is set at 80hz for all the channels). Good engineering!

Eric,

One of the things I did with my set-up was to set my receiver to normal listening volume and then measure the SPL out of the 80s without a sub at the cross-over frequency (80Hz). I then adjusted my 600 to have the same output at the cross-over frequency by shutting the 80s off and playing the 80Hz tone. Is that what you did as well?

Not yet. I will try that tomorrow.

BTW, I meant "good idea, I'll try that tomorrow"

Let us know what you find out. In my room, at -20dB on the Denon (about a half watt into my 80s), I get 96dB without the sub. Way too hot I know but I haven't figured out what to do about it.

BTW, are you going to carry that meter around with you now? It's fun measuring different sound sources .

I have taken mine to work and measured the levels of the conveyor lines, the pressure washer back in our shop, my impact gun, impact hammer, etc. In the car and truck and at home I have checked my A/C compressor for my house, the furnace blower at the vents, my kids when they are wrestling......... it is fun.

Question: what are you using as source? A test signal that is at max volume? I tried a 440hz test signal at max moving from -30 to -18db and I got around 82-94 db at 4 feet (single channel). I also have "half-volume" test signals for 30, 40, 50 and 60hz.

I use a test CD that has different tones recorded on it. The tones are recorded at -10dB.

Are the tones simple sine curves at exact wave lengths?

Just tried with my current tones (at -10db or 1/2 volume).
40, 50, 60 hz shows up at 83db (receiver set at -17db) pretty constant throughout the room with subwoofer and almost all uniform coming from M80s (both channels were used or redirected to sub).

70-100 gives me 85-86db when using the cross-over, 84db with M80s alone. I had to put back the "TRIM=FLAT" on EP-500 otherwise numbers were too high.

So, all in all, sounds good.

I will order an actual test CD. I do not trust those files I am using. So I will not mess with my current setup (which sounds great with AVIA setup) until I put my hands on reliable material.

Amazon should have that, shouldn't they?

Now, let's sit back and enjoy! (I reveiced a bunch of SACDs yesterday)!