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Usefulness of In-Room LF Measurements vs. No Measurements (ref FH)
Usefulness of In-Room LF Measurements vs. No Measurements (ref FH)
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Old 18th February 2015, 11:07 PM   #61
planet10 is offline planet10  Canada
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Usefulness of In-Room LF Measurements vs. No Measurements (ref FH)
Quote:
Originally Posted by pnix View Post
The problem is the driver itself.
Not much of a problem. About 6-8 dB above the average centred at 10k abd n the order of a tenth of an octave wide. And on-axis where most people don't listen to them.

dave
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Old 19th February 2015, 06:08 AM   #62
Dennis Rech is offline Dennis Rech  United States
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Quote:
Originally Posted by pnix View Post
What's causing these colorations in your opinion? How to get rid of it? Is this something that can be measured?
The room surfaces, size and speaker placement all make a big difference in the response that can be measured from the speaker.
Heavy carpet and heavy drapes will suck up all the high frequencies and mute them out. Paneled walls and large glass areas will augment them. Its easy to test in different rooms and get 5 or so db above or below on the mids to highs from what was tested at my testing room. Low frequencies are cut short in small rooms. You cannot generate a 40 foot wave in a 12 foot room. It just doubles back on itself and cancels out or maybe doubles. My corner horns in my 24 foot wide empty shop can show a 10 db change up or down at 50 hz. Move over 3 feet and it will change again. Add machinery to the shop and storage and some furniture and it evens out. Open the big shop door and the bounce is gone.
I used to test speakers out at my dad's very quiet farm, just like AR and KLH, to get a test without room influences. I even built an anechoic chamber ( They are really cool. You can hear the blood squishing through your eyes) for testing. The results were meaningless in both cases because no one but me ( and a few cows) ever listened under those conditions. It is a lot like measuring exactly 3 feet in front of a speaker.
My salesman and I tried really hard to get the speakers to produce a "live" music sound. Then we realized that we had actually heard very little live music. So, being of barely drinking age, we went to a jazz bar and did some heavy research. I was the only drunk in the bar with a sound meter.
Turns out live music has a few flaws and that the venue has just as much influence to live as it has to recorded. If the piano sounds a little tonkie, it might be the their speakers ( lots of electronics in tavern music), or the room or the piano. We sort of tore up the performance with notes about the horns sounding shrill, the vocalist also sounding shrill and the piano getting over thumped by the drummer. Then we realized that that's what live music actually sounds like and that recorded music gets a lot of processing to make it sound like it does.
Recorded music can be to live music a lot like Velveeta is to cheese... processed. Some times it needs processing.
We ended up deciding that the real difference between the two wasn't frequency response or distortion, or anything that is normally tested.
The important thing was dynamic range. In the music clubs, the range from quiet to loud was 45 db to 110 db.
In most house systems, our customers had a background level of 55 and seldom got over 90 db.
So we revamped our speakers to give a little more dynamic range by increasing efficiency and attack and stopped fretting over dead flat frequency response since no one can tell anyway.
Although a few folks have absolutely perfect pitch, the fat guy spitting into the horn on stage probably does not.
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Old 19th February 2015, 04:20 PM   #63
pnix is offline pnix  United States
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Quote:
Originally Posted by planet10 View Post
Not much of a problem. About 6-8 dB above the average centred at 10k abd n the order of a tenth of an octave wide. And on-axis where most people don't listen to them.

dave
Well, this is not true. Please measure the driver yourself and you'll find the (not so pretty) truth.

I can see why some (older) people actually might like such a built-in 'hardware EQ' but I don't think a driver should generally act in such a way. Using electronic EQ is probably more practical and flexible. Not everybody is the same age or has the same hearing loss.

I generally would prefer a driver without these peaks and it looks like there are drivers that actually perform better.
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Last edited by pnix; 19th February 2015 at 04:29 PM.
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Old 19th February 2015, 04:27 PM   #64
pnix is offline pnix  United States
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Quote:
Originally Posted by Dennis Rech View Post
The room surfaces, size and speaker placement all make a big difference in the response that can be measured from the speaker.
Heavy carpet and heavy drapes will suck up all the high frequencies and mute them out. Paneled walls and large glass areas will augment them. Its easy to test in different rooms and get 5 or so db above or below on the mids to highs from what was tested at my testing room. Low frequencies are cut short in small rooms. You cannot generate a 40 foot wave in a 12 foot room. It just doubles back on itself and cancels out or maybe doubles. My corner horns in my 24 foot wide empty shop can show a 10 db change up or down at 50 hz. Move over 3 feet and it will change again. Add machinery to the shop and storage and some furniture and it evens out. Open the big shop door and the bounce is gone.
We can't do much about bad recordings but we can control directivity and absorption in a room. You seem to attribute colorations to the steady-state response minus the direct sound or would you say it's more complicated?
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Old 19th February 2015, 04:46 PM   #65
xrk971 is offline xrk971  United States
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Usefulness of In-Room LF Measurements vs. No Measurements (ref FH)
Quote:
Originally Posted by pnix View Post
Well, this is not true. Please measure the driver yourself and you'll find the (not so pretty) truth.

I can see why some (older) people actually might like such a built-in 'hardware EQ' but I don't think a driver should generally act in such a way. Using electronic EQ is probably more practical and flexible. Not everybody is the same age or has the same hearing loss.

I generally would prefer a driver without these peaks and it looks like there are drivers that actually perform better.
Also, what we have seen from the data is that a peak of that magnitude and narrowness is tantamount to a ringing bell. It will have temporal coloration - a "sonic aftertaste" and sharp percussives that normally would sound soft, end up with enhanced audibility which is sometimes mistaken for having "more low level detail" which was not in the original recording.
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Old 19th February 2015, 07:40 PM   #66
rjbond3rd is offline rjbond3rd
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I call it "zing". I found that I didn't notice it after a few minutes. Personally, it's high enough that I don't mind it.
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Old 19th February 2015, 08:44 PM   #67
pnix is offline pnix  United States
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Quote:
Originally Posted by rjbond3rd View Post
I call it "zing". I found that I didn't notice it after a few minutes. Personally, it's high enough that I don't mind it.
Problem with that 'zing' is that it can create subharmonic distortion.
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