[playntheblues]

Ok, I am ready to start working seriously on my room treatments.  I would like to buy a test disc for both octaves and speaker placement.  I currently have Von S 4.5's silver additions which are just temporary until my LS 9's ship, which should be soon, within a year or two     

Here is a link to one that I have found   http://www.rivesaudio.com/software/softframes.html

Is this a good one, and or what do you guys recommend?

Warm Regards, Guy

[Ethan Winer]

Here is a link to one that I have found   http://www.rivesaudio.com/software/softframes.html

That Test CD is not useful for assessing low frequency response or speaker placement because its test tones are at third octave spacing. To see the true response you need much higher resolution. The best way to do this is with software such as ETF (Windows), Fuzzmeasure (Mac), or Room EQ Wizard (both). This requires a computer connected to your system. If you don't have that, download this Test CD from my company's site for free:

http://www.realtraps.com/test-cd.htm

If you want to learn more about room testing software, this article explains how I use ETF:

http://www.realtraps.com/art_etf.htm

--Ethan

[playntheblues]

Ethan, many thanks.  I think I will start with your down load and get the room a little closer and then look into the software approach.  What do you think?
Guy

[bpape]

You can certainly do that - it just takes time to measure and plot every frequency - though it can be done and will be more accurate than the 1/3 octave.  REW is a free program and it runs sweeps that will plot everything in about 5 seconds.

Bryan

[playntheblues]

HOLY CRAP!  I have read and read and read about how important room treatments are and I have a few but until you measure your room it makes no sense in trying to buy the right gear!   Here are my room measurements.
10-19HZ     -3db
20-29HZ     +5db
30-39hz     -1.5db
40-49hz     +13db
50-59hz     +17db
60-69hz     +15db
70-79hz     +10db
80-89hz     +15db
90-99hz     + 9db
100-109hz  +9db
110-119hz  +5db
120-129hz +1.5db
130-139hz  +11db
140-149db   + 9db
150-159hz   + 8db
160-169hz   +12db
170-179hz   +15db
180-189hz   +16db
190-199hz   +14db
200-210hz   +16db
220-229hz   +15db
230-239hz   +20db
240-249hz   +18db
250-259hz   +11db
260-269hz   + 8db
270-279hz   +17db
280-289hz   +11db
290-299hz   +21db

Makes me wonder whats above 300hz   And the journey begins, more to come.

[martyo]

WOW, may I inquire how you did that so quickly? Thanks

[playntheblues]

I down loaded Ethans test disc and used my Radio Shack SPL metter on C and slow and turned everything off in the house that made any noise at all.

[bpape]

Don't bother above 300Hz - it'll just make you sick.   

Just remember that placement is everything.  You can make DRASTIC changes in those readings moving seating and/or speakers as little as a few inches.  Get that all right first and then see what's left.  That'll give you specifics about what needs to be addressed and where the issues are coming from.

I've seen a LOT worse than that.  You're actually pretty good other than a couple places you're down 8db or so.  Your overall 'zero' leve is around +16.  Realistically, if you can get +/-4 or 5db 20-300, you're doing very well.

Bryan

[zybar]

Those measurements are not at all uncommon Guy.

Go buy or build some room treatments (as well as play around with placement - if possible) and you will see and hear a dramatic change.

George

[playntheblues]

Bryan, at the risk of sounding stupid are you saying to move the speakers a couple of inches and remeasure then repeat this step over and over?  Generally when placing the speakers do you find that the measurements will gradually get better and then gradually get worse so you can zero in on the sweet spot so to speak for placement or is it hit and miss until you find the spot?

[ted_b]

Guy,
Moving the speakers even a few inches or less (especially movement out from front wall) has a dramatic effect.  If you could even borrow someone's Velodyne SMS-1 (some have it as 30 day return policy...but I'm not advocating anything... ) and run it realtime, while moving the speakers, you'll see realtime response (under 100k) on your tv or projector.  Then you could then go back to finer details of ETF or REW and do the tweaking.  My $.02

Are the 10hz-wide measurements averages you took here?  You should likely see spikes within one hertz or so as you approach modes.

[playntheblues]

Ted yes these were 10hz wide average measurements.  I have about 7 feet or so behind the speakers if you look at my avatar you can see the stair well behind the speakers.  The only difference is I have Von S 4.5's instead of the Alphas now.  It seems kind of daunting moving everything and re testing.  I guess I will start with the speakers and then move the furniture to see how that effects everything.

[zybar]

Guy,
Moving the speakers even a few inches or less (especially movement out from front wall) has a dramatic effect.  If you could even borrow someone's Velodyne SMS-1 (some have it as 30 day return policy...but I'm not advocating anything... ) and run it realtime, while moving the speakers, you'll see realtime response (under 100k) on your tv or projector.  Then you could then go back to finer details of ETF or REW and do the tweaking.  My $.02

Are the 10hz-wide measurements averages you took here?  You should likely see spikes within one hertz or so as you approach modes.

One little correction...

The SMS-1 will only show up to 200Hz.

George

[ted_b]

George, Thanks.  I meant 100hz, not 100K.     Most believe the SMS-1 to be accurate only slightly above 150hz (maybe it's the mic, dunno, never asked SMS to do anything above 100 for me anyway) even though it may show higher crossovers.  But if you can tackle 150hz and below in big chunks you are way ahead of the game.

[bpape]

REW's latest release also lets you run an RTA to make things much easier.

Yes - speaker positioning and seating positioning are critical.  I generally try to do the seating first and then play with speakers to balance response, imaging, etc. 

Bryan

[Ethan Winer]

are you saying to move the speakers a couple of inches and remeasure then repeat this step over and over?

Yes, which is why software is much better - if you have a computer connected to your audio system.

--Ethan

[mixsit]

..Makes me wonder whats above 300hz   And the journey begins, more to come.

A quick easy example- play a low-mid sine wave mono from both speakers- step side to side a foot or so.

Regarding room speaker and listening placement, have you guys seen these?

http://www.hunecke.de/en/calculators/loudspeakers.html

http://www.hunecke.de/en/calculators/room-eigenmodes.html
I've just run into them, looks very informative and useful. Just playing with the 'Room mode calc is a good visual of  what we're dealing with.
Wayne

[playntheblues]

Lot's of good info ty all.  I still need to get a picture of my room over to Ethan