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Post by Deleted on Oct 25, 2015 6:17:29 GMT -5
Hmm, my speakers have two 10" drivers, and are sealed, and are rated down to 22hz Either they are 8' tall , have tons of distortion or the rating is Bs And IN ROOM at port tune a sealed sub will have the output advantage but above and below that tune the room gain will give the sealed the advantage in output
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Post by guzz46 on Oct 25, 2015 17:58:45 GMT -5
Hmm, my speakers have two 10" drivers, and are sealed, and are rated down to 22hz Either they are 8' tall , have tons of distortion or the rating is Bs And IN ROOM at port tune a sealed sub will have the output advantage but above and below that tune the room gain will give the sealed the advantage in output They're roughly about the same size as the PSA's, maybe slightly smaller, as for distortion and measurements, you'll have to take that up with Bill Dudleston, all I know is they sound amazing, here's a quote from him on the topic The key in Signature SE low frequency design is the low cone mass AND compliant suspension which provides a low enough fs in this four foot tall enclosure. Additionally the sealed box allows us to apply impedance transformation to increase voltage to the driver selectively. The speakers roll-off is long and slow allowing one to place the speaker closer to the rear boundary and utilize this gain without droning. Of some interest to this discussion my colleague Don Keele noted room gain was typically +12 dB at 20 Hz in his room, falling off to about +1dB at 100 Hz. In the hundreds of rooms that I have conducted setups and room correction I found this a good rule of thumb. When factoring theoretical room gain, remember free space, modeled as an a sphere with the loudspeaker at the center, subtends 4 pi square radians (steradians) about the origin. Bisect the sphere horizontally (add a floor) and you receive 6dB of boundary gain at low frequencies as the radiation angle decreases to 2 pi steradians. Slice it in half vertically and we get another 6 dB of boundary gain as we add the rear wall. Slice it once more and the sphere is down to pi/2 steradians (1/8 space) as we have added a side wall to form a corner and we are up 18dB. Now form a mirror image of this corner across the diagonal and we have a ceiling corner and at very long wavelengths we are up another 6 dB. As we bring these boundaries together to form a typical six-sided room the phenomenon of pressurization occurs as the room get smaller and acoustic radiation impedance increases. So here's the deal: Rooms are lossy at some frequencies as boundaries flex and leak, but we cannot treat the speaker model as it is on a pole in free space -unless that is where we are going to use it (emergency warning sirens,etc.). The contribution of boundary gain is a key part of the equation.
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Post by Deleted on Oct 25, 2015 18:13:41 GMT -5
Are they 84db efficient?
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Post by guzz46 on Oct 26, 2015 0:26:02 GMT -5
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Post by Deleted on Oct 26, 2015 7:01:42 GMT -5
In room has nothing to do with efficiency. Efficiency is measured in an open field at 1m And again I call fiddlesticks. You can't cheat physics. With a sealed speaker design you can't have Extension Efficiency Small cabinet You can have two of the three but not all three Room gain will not help you that much. Your trying to say your small mains will get the same extension as a subwoofer. Not possible. If it is then there are tons of distortion and ringing that I'm sure won't sound good Again coming from the guy who is trying to sell a speaker. Of course he is going to back his claim And if it Is even possible with room gain, you have to jam the speaker in a corner. So you are now sacrificing the sound of the speakers bread and butter range Why is this going around and around. Please do a google search. Physics do not lie But ULTIMATLY if they sound amazing the rest is just a posing contest. So enjoy your speakers
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Post by MusicHead on Oct 26, 2015 7:09:48 GMT -5
+1, it is called "Hofman’s Iron Law" or in simpler terms "you can't have the cake and eat it too" :-) For a more authoritative source, read this from Mr. Salk himself: www.salksound.com/wp/?p=56
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Post by Deleted on Oct 26, 2015 9:27:00 GMT -5
In room has nothing to do with efficiency. Efficiency is measured in an open field at 1mAnd again I call fiddlesticks. You can't cheat physics. With a sealed speaker design you can't have Extension Efficiency Small cabinet You can have two of the three but not all three Room gain will not help you that much. Your trying to say your small mains will get the same extension as a subwoofer. Not possible. If it is then there are tons of distortion and ringing that I'm sure won't sound good Again coming from the guy who is trying to sell a speaker. Of course he is going to back his claim And if it Is even possible with room gain, you have to jam the speaker in a corner. So you are now sacrificing the sound of the speakers bread and butter range Why is this going around and around. Please do a google search. Physics do not lie But ULTIMATLY if they sound amazing the rest is just a posing contest. So enjoy your speakers I'm only posting this quote below because I remember it from reading a review by Brent Butterworth in Home Theater Review on the ML Motion 60XT speaker. Do you perhaps mean speaker sensitivity? I think Brent disagrees since the implication here is that sensitivity is usually measured in an anechoic chamber and it can be different in-room with 2.83v (1 watt into 8 ohms) at 1 meter. Legacy in fact does use in-room to state their Signature SE tower, " Sensitivity: (Room, dB@ 2.83V) 92 dB." Sensitivity of this speaker, measured quasi-anechoically from 300 Hz to 3 kHz, is comfortably high at 90.6 dB. You should get about +3 dB more output in-room, so the 94dB rating seems reasonable.
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Post by Deleted on Oct 26, 2015 9:37:22 GMT -5
+1, it is called "Hofman’s Iron Law" or in simpler terms "you can't have the cake and eat it too" :-) For a more authoritative source, read this from Mr. Salk himself: www.salksound.com/wp/?p=56Thank you. Could not think of it for the life of me
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Post by pedrocols on Oct 26, 2015 11:38:59 GMT -5
In room has nothing to do with efficiency. Efficiency is measured in an open field at 1mAnd again I call fiddlesticks. You can't cheat physics. With a sealed speaker design you can't have Extension Efficiency Small cabinet You can have two of the three but not all three Room gain will not help you that much. Your trying to say your small mains will get the same extension as a subwoofer. Not possible. If it is then there are tons of distortion and ringing that I'm sure won't sound good Again coming from the guy who is trying to sell a speaker. Of course he is going to back his claim And if it Is even possible with room gain, you have to jam the speaker in a corner. So you are now sacrificing the sound of the speakers bread and butter range Why is this going around and around. Please do a google search. Physics do not lie But ULTIMATLY if they sound amazing the rest is just a posing contest. So enjoy your speakers I'm only posting this quote below because I remember it from reading a review by Brent Butterworth in Home Theater Review on the ML Motion 60XT speaker. Do you perhaps mean speaker sensitivity? I think Brent disagrees since the implication here is that sensitivity is usually measured in an anechoic chamber and it can be different in-room with 2.83v (1 watt into 8 ohms) at 1 meter. Legacy in fact does use in-room to state their Signature SE tower, " Sensitivity: (Room, dB@ 2.83V) 92 dB." Sensitivity of this speaker, measured quasi-anechoically from 300 Hz to 3 kHz, is comfortably high at 90.6 dB. You should get about +3 dB more output in-room, so the 94dB rating seems reasonable. I wonder who here volunteered his or her room for this measurements.....I know it wasn't me....
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Post by guzz46 on Oct 26, 2015 12:33:43 GMT -5
In room has nothing to do with efficiency. Efficiency is measured in an open field at 1m And again I call fiddlesticks. You can't cheat physics. With a sealed speaker design you can't have Extension Efficiency Small cabinet You can have two of the three but not all three Room gain will not help you that much. Your trying to say your small mains will get the same extension as a subwoofer. Not possible. If it is then there are tons of distortion and ringing that I'm sure won't sound good Again coming from the guy who is trying to sell a speaker. Of course he is going to back his claim And if it Is even possible with room gain, you have to jam the speaker in a corner. So you are now sacrificing the sound of the speakers bread and butter range Why is this going around and around. Please do a google search. Physics do not lie But ULTIMATLY if they sound amazing the rest is just a posing contest. So enjoy your speakers Well that would depend on the sub woofer wouldn't it, you can call fiddlesticks all you want, but I actually own them so I can speak from experience, in my small room they can easily play down to 30hz, after that they drop off down to about 25hz, but I suspect this is a room mode because my subwoofer does the same, I don't have the proper equipment to measure them using R.E.W. only a laptop, so this is going by test tones only.
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Post by Deleted on Oct 26, 2015 12:45:05 GMT -5
What? You were talking about a loud speaker with 2 10" drivers. Now your talking about a sub? Which is it?
And how can it drop after 30hz if it's "rated" to 22hz. Like I said hogwash
And if you can't measure it. I REALLY don't believe it
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Post by guzz46 on Oct 26, 2015 17:13:30 GMT -5
What? You were talking about a loud speaker with 2 10" drivers. Now your talking about a sub? Which is it? And how can it drop after 30hz if it's "rated" to 22hz. Like I said hogwash And if you can't measure it. I REALLY don't believe it I'm not talking about a sub, you said I claimed that my small mains will get the same extension as a subwoofer, so I said it depends on the subwoofer, not all sub's measure the same. I'm sure you've heard of room modes before? Peaks and nulls? That is why they drop off after 30hz, just like my sub does, in my room there is a peak at around 60hz and 30hz, and a null below 30hz, both my mains and my sub are effected by it, put them in a different room and I'll get different measurement's, so even if I did post my R.E.W measurement's (taken with a laptops mic) all that would show is how they measure in my room with inappropriate measuring equipment. So it can be measured, and no I'm not a liar, you can believe what ever you want to believe, but just believing in something doesn't make it true.
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Post by Deleted on Oct 26, 2015 18:06:55 GMT -5
I'm not saying your a liar. I'm saying the specs on your speakers are not truthful. If your speakers are the size, design and efficiency they claim
Klipsch also says their reference line has a sensativjty of 101db. Which when bench tested is closer to 92db
So I take all manufacturer specs with a grain of salt.
But what you and the designer are claiming is basically impossible
And as far as your null is concerned. If your sub and two speakers go to 22hz as it is claimed all three would smooth that null you claim to have. Did it ever occur to you that none of the three have the extension you were lead to believe they have. Especially with room gain they claim to use
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Post by guzz46 on Oct 26, 2015 18:41:58 GMT -5
I'm not saying your a liar. I'm saying the specs on your speakers are not truthful. If your speakers are the size, design and efficiency they claim Klipsch also says their reference line has a sensativjty of 101db. Which when bench tested is closer to 92db So I take all manufacturer specs with a grain of salt. But what you and the designer are claiming is basically impossible And as far as your null is concerned. If your sub and two speakers go to 22hz as it is claimed all three would smooth that null you claim to have. Did it ever occur to you that none of the three have the extension you were lead to believe they have. Especially with room gain they claim to use They probably aren't 100% accurate, most probably like most speaker ratings, I don't know if they truly play down to 22hz +/- 2db as I've only heard them in my room, but they do play low, in my room about 30hz lower than the PSA's specs, how low they play would depend on the room, and placement. There's measurements showing the PC13-Ultra plays down to 20hz +/- 3db with all ports open, so that definitely does, I listen in 2 channel only, not 2.1, so the sub isn't going when I listen to music, or when I measured my mains, so there's still nulls.
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Post by MusicHead on Oct 26, 2015 19:28:16 GMT -5
+1, it is called "Hofman’s Iron Law" or in simpler terms "you can't have the cake and eat it too" :-) For a more authoritative source, read this from Mr. Salk himself: www.salksound.com/wp/?p=56Thank you. Could not think of it for the life of me You are welcome. Lest we forget that, while audio design might be a mix of engineering and art, the laws of physics still apply!
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Post by jmilton on Oct 26, 2015 19:36:39 GMT -5
You can not break the laws of physics...but you sure can bend them a bit.
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novisnick
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Post by novisnick on Oct 26, 2015 19:56:40 GMT -5
You can not break the laws of physics...but you sure can bend them a bit. Yes, I think he has detailed how much he bent his wrist! I may be speaking about something completely different,,,,,he,,,,,he,,,,he,,,,,,
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DYohn
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Post by DYohn on Oct 26, 2015 20:15:17 GMT -5
All the would-be loudspeaker system designers on this thread should Google "boundary gain."
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Post by guzz46 on Oct 26, 2015 20:19:00 GMT -5
So what is the magic formula then?
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hemster
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Post by hemster on Oct 26, 2015 20:19:47 GMT -5
All the would-be loudspeaker system designers on this thread should Google "boundary gain." ...and thereafter Google "boundary gain compensation".
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