Orange Peel Posted November 6, 2003 Share Posted November 6, 2003 I just did a little SPL reading with the 3 20-39's, I used the Scene in Finding Nemo when Darla is tapping on the glass..... From my seating position with the Radio Shack meter set to C weighting and fast response I was only getting about 113db's during that scene. That's with the gain on the PC+ at around 1/3 or so and the Samson S1000 full cranked on the amp. The Pioneer Elite's sub setting is -9 too. I tried to mess with the phase on the PC+ a little to see if there was any change, when I adjusted it off of 0, it loss some db's. So I will hook up the black box and see if adjusting the phase on the CS's will make a difference. I must say that scene is loud, I know my house will start to crack at that much bass constantly It rattles the crap out of the windows that they are next to. What do you think of 113db's?? I should be able to get some more, I NEED more I should say Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted November 6, 2003 Share Posted November 6, 2003 Orange Peel: Darn, how big is your room? I wasn't taking measurements when we listened to Finding Nemo. When the tapping on the glass started or the submarine slid off the ledge, we were shaking in our seats. I only have one SVS sub and I can't imagine having more. My room is about 27x14. Besides, you are getting tremendous sound pressure levels anyway. Also, with three subs, if they are not all perfectly in phase, you are defeating the purpose of getting max bass. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted November 6, 2003 Share Posted November 6, 2003 Also, remember the SPL vs. amp power relationship. Quote Link to comment Share on other sites More sharing options...
Orange Peel Posted November 6, 2003 Author Share Posted November 6, 2003 My room is about 25' deep, 25' wide, 8' ceilings, opening to the kitchen, opening to the hallyway, openeing to the bedroom, front door and entry way there too. Lots of area so it's not a sealed room at all. I was getting beat up for sure when that scene was on but I was wondering what others have recorded during that scene or in general, is 113db's good?? I can never have too much bass It will take some time and work to get them in phase percectly, but I feel they are in decent phase right now seeing as how I tried to mess with one so far and it didn't help any. Quote Link to comment Share on other sites More sharing options...
Orange Peel Posted November 6, 2003 Author Share Posted November 6, 2003 I don't understand the graph you posted? My CS's are getting 500w each, the PC+ is getting 525w. Not sure how to go about reading that graph Quote Link to comment Share on other sites More sharing options...
Colin Posted November 6, 2003 Share Posted November 6, 2003 My study of several dozen audiophile loudspeakers showed the average sensitivity to be 84-86 dB, rated at one watt of power and measured about three feet away (one meter), without including big ole horns. Live orchestral music can have brief musical peaks as much as 130dB! To reproduce conversational levels (75dB) a conventional loudspeaker rated at 84dBw needs 1/8 of a watt (.125). To reproduce a live orchestral music peak from a CD, a conventional loudspeaker needs at least 15dB of gain or 90dB (75, plus 15) or 4 watts. To reproduce a live orchestral music peak at the same volume, a conventional loudspeaker needs more than 4,000-watts! Now, run the numbers for super-sensitive loudspeakers, rated at 90 db per watt per meter: Conversational levels (75dB) require 1/30 of a watt. To reproduce a live orchestral 90db music peak from a CD, they need just one watt! To reproduce a live orchestral music peak at the same volume, super-sensitive loudspeakers still need more than 1000-watts. Now, compare ultra-sensitive big ole horns, rated at an amazing 99 db per watt per meter: Conversational levels (75dB) require just .004 of a watt! To reproduce a live orchestral 90db music peak from a CD, they need a bare 1/8 watt! And, to reproduce a live orchestral music peak at the same volume, big ole horns need just 128-watts! The reality is that even incredibly efficient big ole horns will require more power than the chart shows to recreate music in a living room. Most receivers do NOT show the relative percent of power that their amplifier is pushing out: their knobs usually give most of the power out between 7 and 10:00 on the dial. My Dynaco Pass 2, series II, does show the amount of power it is asking from the amplifier: 9:00 on the dial is about ¼ power. Therefore, about 3-watts on my big ole Klipsch classic corner horns will pump out about 100db at my listening place, 9 feet away. In other words, about double the power requirements shown on the efficiency/SPL chart. This means you can double the theoretical wattage required by the comparisons above for the real world! As for subs, my ill-fated Klipsch LF10 sub-woofer, with its 500-watt amplifier, one active and two passive 10 drivers, at ¾ power on its power settings, puts out 90dB SPL (at 31.5 Hz). Quote Link to comment Share on other sites More sharing options...
TheEAR Posted November 6, 2003 Share Posted November 6, 2003 113dB is not bad but if you seriously want more then get serious,get a SVS B4-Plus you will reach your dB goal. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted November 6, 2003 Share Posted November 6, 2003 In essensce, what the chart shows you is that in order to increase your output by 3dB's, you need to double the power. So, if your amp is maxed out at 113dB's, you are not going to get to 116 dB's without doubling the amp power. Frankly, with the layout that you have, I don't see how you are going to get much more. Do you really need more, 113dB's is extremely loud. Your ears could take a beating too, and those are next to impossible to fix one you damage them. Quote Link to comment Share on other sites More sharing options...
formica Posted November 6, 2003 Share Posted November 6, 2003 ---------------- On 11/6/2003 11:30:44 AM Orange Peel wrote: My room is about 25' deep, 25' wide, 8' ceilings, opening to the kitchen, opening to the hallyway, openeing to the bedroom, front door and entry way there too. Lots of area so it's not a sealed room at all. I was getting beat up for sure when that scene was on but I was wondering what others have recorded during that scene or in general, is 113db's good?? ---------------- Your room is huge ! Is this reading for just the sub or the sub and mains as well? It's pretty much impossible to compare the maximum output with movie source material (I assuming that is what your looking into?)... You'd need to crack out a test CD to get a better idea of what your system is capable of, then push your sub amp to "near" clipping or woofer just short of bottoming out. Even with a controlled test material there are still several ways you can test your sub. It's not unusual to have higher in-room SPL on full frequency music... but I wouldn't worry to much about the Nemo test. It's in the ballpark but there are too many variables to compare. Rob Quote Link to comment Share on other sites More sharing options...
Orange Peel Posted November 6, 2003 Author Share Posted November 6, 2003 Colin - Damn dude, that was a great explanation, pretty descriptive too, thanks buddy! Ear - Do you think I could get some more db's out of this setup? I know it would be ideal to have them all in one corner, but that's not possible in this house, maybe the next one. I wish I have the cash to dump on that B4+, it would be UNREAL to have one of those, maybe 2 What is "reference" bass db's?? Rudy - Thanks for the chart and the explanation!! I don't know what else I can acheive with the crappy room layout, but it's definitely not bad right now It's a ton of bass, but there's never enough clean deep bass It's not like there's 113db's constantly, so I am not too worried about my ears, I have listened to MUCH louder music in my car than at home. Rob - Yeah the room plays a big part in the bass formula, that's why I wanted more subs. I am using all my Klipsch in LARGE setting. Ideally I would love to have Quad SVS Ultra's, but my bank account says hell no right now I have the Avia disk on it's way to me, so I will see what that can do for me. I am not really looking to get max output or anything, just clean deep bass, and if that makes a lot of SPL, then I am cool with that What other variables is there that I should concern myself with? One thing I need to take care of is the rattling that I have now Quote Link to comment Share on other sites More sharing options...
TheEAR Posted November 6, 2003 Share Posted November 6, 2003 Scott, You do not have to pile them all in one corner,as I can understand this with all my subs.Just position them close to one corner(say on in corner,the two other close along side the same wall) Make sure all subs are alonside a wall and do not sit near open spaces,too much deep bass output is lost this way.Try to sit on the opposite side of the subs and if at all possible where you have a wall behing you(bass further reinforced). Do not worry about "low" readings in some positions,as bass is NEVER even in the room(unless you like in a perfect sphere and the sub is located at its center.Make sure bass level and "quality" is great where you sit. I follow these simple guidlines and my systems sound majestic,efortless and simply great.With dB's to spare. In the current position you may need extreme subs to get above 120dB's.And who needs close to 120dB in room....well ok I need it. Placement of a sub can make or break the bottom end,even the best subs when not placed in an optimal position may disapoint.And a so so sub when set to near perfection may impress in a good way. As for REFERENCE SPL to me its 120dB sustained,and 126dB on peaks.At listening position,not any one will need this or be crazy to listen at this extreme of a volume but...better have the extra juice just in case anyone angers me. Right now both my systems can reach 116dB and up at listening position at 25Hz,a very impresive figure,And at 31.5 they best 120dB's with ease.When I finish adding the subs(SVS,Paradigm and Acoustic Visions)the numbers should be 116 or more at 20Hz and over 130dB at 31.5Hz. Will be there just in case Quote Link to comment Share on other sites More sharing options...
fabulousfrankie Posted November 6, 2003 Share Posted November 6, 2003 The RS SPL meter is grossly inaccurate for reading lower freq's as you probably already know. I've also read Dan Wiggins state besides it reading low in the lower frequency range, he said it reads low for SPL peaks as well. I'm not really sure if there is a way to accurately say what the true reading for SPL peaks would be, but it is safe to say you're actually hitting more than 113dB. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.