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Discussion Starter #1
Hi guy's, First Merry Christmas and Happy new year. I hope you and yours are well. I finally burned a test cd to test my new diy Shiva and ED subs whisch are located mid wall left of the viewing area and stacked.They are powered by the EP-2500 and taken at the listening position. I ran tones from 20 to 80hz at 5hz intervals and this is with an eq'ed room response as flat as I could get it. Here are the results.............

20hz-102db
25hz-101db
30hz-101db
35hz-101db
40hz-97db
45hz-102db
50hz-101db
55hz-95db
60hz-94db
65hz-101db
70hz-103db
75hz-106db
80hz-104db

Ok, this was with the system calibrated to 75db levels both mains and sub. What good or bad does thIs test show me. Should I go into the sms1 and bump those lower readings up to be more equal or is this something I should be happy with. Any advice you guy's have would be super. THANKS...:T
 

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Hi TC, The results look good. You're within +-3 db almost everywhere (I'm assuming you have measured properly.

My opinion is leave it that way if it sounds good. You're curve should be pretty flat :T

Don't do these tests to check the max output of your sub using sin waves.... You might damage it.
 

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Discussion Starter #3
Thanks, I thought sinwaves was the way to do it. What should I have used. Also I used the Rad shack spl meter for everything taking into account the correction for that meter.
 

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Well, with sin waves and enough power it is quite easy to reach over excursion. When I need to know how loud my system plays, I use a loud bass scene from a movie (like WOTW for ex.).
 

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Discussion Starter #5
Well that way it is harder to see what is happening at exact freq's. It didn't seem to bother the subs at all. I got clean bass at each step with no funny sounds or mechanical sounds of any kind.
 

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I am talking about Max SPL. Sin waves are OK for FR (moderate SPL and that's the most important. Max SPL might have a different behavior from FR (specially when equalizing)....

DO NOT USE A SIN WAVE AT SINGLE FREQ. TO CHECK HOW MUCH YOUR SUB HITS AT THAT FREQ. PROCEED AT YOUR OWN RISK.
 

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Discussion Starter #7
Got Ya........I will be carefull and will test on a movie like you mentioned. Wotw or U-571 should do it, Thanks.
 

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DO NOT USE A SIN WAVE AT SINGLE FREQ. TO CHECK HOW MUCH YOUR SUB HITS AT THAT FREQ. PROCEED AT YOUR OWN RISK.
Now you're telling me this :paddle:.

I did that mistake before (I was measuring TSS750 and Velo VRP1000); after a couple of minutes I smelled like something was burning and my AVR was hot ...after those test when watching movies with a lot of bass, I can smell something coming from TSS :whistling:

(To test the subs, I used my reference level and played sinewaves from 10Hz to 200Hz :hide:)
 

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Hey David,

Sorry, I never knew you did tests that way...:no:
Do not worry about smelling things. As far as everything's working OK, you didn't burn anything :T. I don't know your AVR but most of them normally have protections.
Well well well, a short circuit in the speakers wiring cables burnt 3 transistors and few resistances in my Yammie RX-V2500 2 years back. But I was watching a concert at insane an level when that happenned. My guess is protection didn't trigger soon enough, but normally it shouldn't have happened, so do not worry :).

Just use normal material with your SPL meter at LP and measure as you wish.
 

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I use sine sweeps and single frequency tones for my tests (FR, power compression,THD, etc.), but I don't recommend it to anybody. It would not be hard to melt a coil, fry an amp , or hard bottom a driver if you mess up or don't know what you are doing.
 

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Discussion Starter #11
I use sine sweeps and single frequency tones for my tests (FR, power compression,THD, etc.), but I don't recommend it to anybody. It would not be hard to melt a coil, fry an amp , or hard bottom a driver if you mess up or don't know what you are doing.
That is how I did it. I guess I did it right because I had no problems.
 

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Not having a problem doesn't necessarily mean you didn't stress the driver!
I used to do it also with my old 12" sub (never had a problem, but I knew it was wrong and I didn't care). But I dare not do it with my LLTs for obvious reasons :yikes: :R.... Anyway I believe this kind of test is meaningless.
 

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Discussion Starter #13
I agree so I won't be doing it that way again. I will just use a movie or music if I need to.
 

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I agree so I won't be doing it that way again. I will just use a movie or music if I need to.
Me too ... I learned my lesson :sad:

I think a good clip to measure the SPL is the DVE intro ...I think is a plane flying over :scratchhead:
 

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Try WOTW or C&C if you really wanna test the sub :)
 

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Try WOTW or C&C if you really wanna test the sub :)
What is C&C??? ...Do you mean Master and Commander??? (I watched last thursday :whistling:) ...I have a lot of movies with bass (I need to re-watch Transformers, U571, StarWars, etc. with my new sub :yes:); I was thinking the DVE clip because is easy to find :hide:
 

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OK, So my question is do I play the movie at 0 master level because that is where my ref level was set at?
 

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OK, So my question is do I play the movie at 0 master level because that is where my ref level was set at?
I think you can, but I don't know if will be a good idea, just be prepared...:yes:

Last night I measured at the listening position, I played two clips: Finding Nemo, when the girl tap the fish tank ...the SPL read 110db; then U-571, deep charge ...here I got 100db-106db :yay:

My reference volume is set @ -5.0db not 0.0db (I'm also using a separate amp for the fronts, so I can't use 0.0db as reference); the master volume was set @ -20.0db (so, -15.0db below reference) and it was LOUD!!!! ...I'll be afraid to take a measurement of the same clips at reference levels :scared: . :hide: (but I'm sure I'll get reading above 115db).
 

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Discussion Starter #19
I use all seperate amps too and it gets scary loud. I never listen that loud but it is nice to have all that headroom.....:yes:
 

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My reference volume is set @ -5.0db not 0.0db (I'm also using a separate amp for the fronts, so I can't use 0.0db as reference); the master volume was set @ -20.0db (so, -15.0db below reference) and it was LOUD!!!! ...I'll be afraid to take a measurement of the same clips at reference levels :scared: . :hide: (but I'm sure I'll get reading above 115db).
What makes you think you can't use 0.0dB as a reference because you're using separate front amplifiers? Calibration, whether done automatically or manually, will take into account the different gain of a separate amplifier compared to a receiver's built-in amplifiers.

Totally agree though, reference level is LOUD! :hsd: :hush: We did watch Master and Commander at -5dB from reference a few weeks ago though, and subwoofer was actually set 5dB hot, so it was technically at reference level. It sounded quite good, I must say. The canons definitely packed a bit more punch than with my old dynamically limited woofer!
 
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