This weeks episode is about line sources.

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Danny Richie

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justinloving

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Re: This weeks episode is about line sources.
« Reply #1 on: 25 Sep 2019, 03:30 pm »
I’m highly interested in hearing more about this upcoming true line source you talked about in the video. Do you have more information somewhere online or in this forum about it?

Danny Richie

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Re: This weeks episode is about line sources.
« Reply #2 on: 25 Sep 2019, 03:35 pm »
I’m highly interested in hearing more about this upcoming true line source you talked about in the video. Do you have more information somewhere online or in this forum about it?

See some information here: https://www.audiocircle.com/index.php?topic=165469.0

Development of this version: https://www.audiocircle.com/index.php?topic=159717.0

Something on the originals that were in milled aluminum: https://www.audiocircle.com/index.php?topic=137990.msg1469047#msg1469047

Elizabeth

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Re: This weeks episode is about line sources.
« Reply #3 on: 25 Sep 2019, 05:00 pm »
Thank you !!! Really interesting video !!! I like how, at key points you LOOK at us (the camera). Felt like you were really speaking to me. Great topic.
I use Magnepan 20.7, I am assuming the ends of the 5 ft long tweeter ribbon behave like your line array, just a bit smoother (less of those ripples??)
And thanks again for a really great informative video.  :beer:

Danny Richie

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Re: This weeks episode is about line sources.
« Reply #4 on: 25 Sep 2019, 05:11 pm »
Thank you !!! Really interesting video !!! I like how, at key points you LOOK at us (the camera). Felt like you were really speaking to me. Great topic.
I use Magnepan 20.7, I am assuming the ends of the 5 ft long tweeter ribbon behave like your line array, just a bit smoother (less of those ripples??)
And thanks again for a really great informative video.  :beer:

Thanks Elizabeth,  And your earlier tips were very helpful.

At the ends of the line, on your Maggies, (even as you near the ends) you'll notice the top end will start dropping out.

And if you take a group of measurements from on axis, and several inches at a time up and down, you'll see some ripples moving around a little bit up top.

revg1952

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Re: This weeks episode is about line sources.
« Reply #5 on: 25 Sep 2019, 09:53 pm »
Danny
 More fabulous useful and fun Info
Thnx
 RevG

Tyson

Re: This weeks episode is about line sources.
« Reply #6 on: 25 Sep 2019, 11:38 pm »
I like how you articulate what will and what won't work from a design perspective.  For example, I had no idea that power response increased as frequency lowered.  Good stuff!

BobRex

Re: This weeks episode is about line sources.
« Reply #7 on: 26 Sep 2019, 12:08 am »
Great video.  There is one thing that always confused me.  I'm not 100% on the limited vertical response, i.e ceiling splash.  Let's say you built an array of dome tweeters, and were able to get them close enough to not comb filter.  A singular tweeter would have almost perfect hemispherical radiation.  How does stacking them reduce ceiling splash?  Wouldn't the top most tweeter still have a hemispherical wave and radiate into the ceiling?

artur9

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Re: This weeks episode is about line sources.
« Reply #8 on: 26 Sep 2019, 01:30 am »
I thought true line sources had to be floor-to-ceiling (so, like 8-9 ft).

Danny Richie

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Re: This weeks episode is about line sources.
« Reply #9 on: 26 Sep 2019, 02:29 am »
Great video.  There is one thing that always confused me.  I'm not 100% on the limited vertical response, i.e ceiling splash.  Let's say you built an array of dome tweeters, and were able to get them close enough to not comb filter.  A singular tweeter would have almost perfect hemispherical radiation.  How does stacking them reduce ceiling splash?  Wouldn't the top most tweeter still have a hemispherical wave and radiate into the ceiling?

Whether you use ribbons or domes (if you could stack them close enough together) the radiation pattern is the same. And the comb filtering effects will knock the output from the top drivers before you even get even with them. They won't have any output above them just like a long ribbon.

rdkusher

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Re: This weeks episode is about line sources.
« Reply #10 on: 26 Sep 2019, 03:50 pm »
i really learned a lot from this one.i had very little previous knowledge about line sources.i have never had the room they require so i never looked into them.judging by the size i always assumed they would create larger than life images that might not necessarily scale properly but now based on your explanations it looks like that may not be the case.

Danny Richie

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Re: This weeks episode is about line sources.
« Reply #11 on: 26 Sep 2019, 04:28 pm »
I thought true line sources had to be floor-to-ceiling (so, like 8-9 ft).

Length of the line depends on how far away you are. You have to be in the near field. 

Skiman

Re: This weeks episode is about line sources.
« Reply #12 on: 27 Sep 2019, 05:31 am »
At one time I had three 82" tall GR Research LS9s. How I wound up with three is another story.  In order to clear my non acoustically perforated 123" home theater screen, I originally mounted the center LS9 horizontally just below the screen on a sturdy stand. Listening to this center channel  (on it's side in this case)  gave me a rather unique opportunity to hear the sound beyond it's length unrestricted by a ceiling or floor. This resulted in a very dramatic drop in volume level, which of course was just as it was designed to do. Staying within it's length and sound level was fine, however. Ultimately, I replaced it with a GR Research LSC, designed as a center channel type speaker to match my upright LS9s. Still enjoying them all immensely.

Before


After









emailtim

Re: This weeks episode is about line sources.
« Reply #13 on: 30 Sep 2019, 04:42 am »
https://www.youtube.com/watch?v=-GVdYAQkD8I

Danny,

Thanks for the video on the line arrays, very informative.

Can you post a waterfall plot of the Neo10/3 line arrays ?  I would very much like to see what their decay looks like in the line array compared to BG's plots.  Feel free to throw in any other plots of the Neo10/3 line arrays as well.

Would love to hear them.

Thanks much.

Danny Richie

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Re: This weeks episode is about line sources.
« Reply #14 on: 30 Sep 2019, 03:49 pm »
Danny,

Thanks for the video on the line arrays, very informative.

Can you post a waterfall plot of the Neo10/3 line arrays ?  I would very much like to see what their decay looks like in the line array compared to BG's plots.  Feel free to throw in any other plots of the Neo10/3 line arrays as well.

Would love to hear them.

Thanks much.

It's nearly impossible to get an accurate water fall plot on a line source. The distance required to take an accurate measurement includes a floor reflection. So the time window, even if gated, is too long.

I have some of the Super Mini though. It is super clean.

See some measurements here: https://www.audiocircle.com/index.php?topic=164376.0

emailtim

Re: This weeks episode is about line sources.
« Reply #15 on: 30 Sep 2019, 05:59 pm »
It's nearly impossible to get an accurate water fall plot on a line source. The distance required to take an accurate measurement includes a floor reflection. So the time window, even if gated, is too long.

I have some of the Super Mini though. It is super clean.

See some measurements here: https://www.audiocircle.com/index.php?topic=164376.0

Thanks Danny, but I would still like to see the waterfall of the Neo10/3 line sources in an actual listening room, not an anechoic chamber. 

I posted my waterfalls of my line sources in my listening room and the floor/ceiling issue was never raised when they were posted. 

Nobody that I know plays their gear in an anechoic chamber and most people understand that as reality.  It is, what it is and the room (for better or worse) is a part of our playback system so let's see what they look like in a real listening room.  Feel free to add all the room related information (e.g. dimensions) and caveats you deem necessary so readers know it is NOT an anechoic chamber.

TIA

FWIW, Here are my GR/Rythmik H-Frame OB/Dipole subs and Magnepan 20.1's again in my listening room which is by no means an anechoic chamber.  The vertical axis shows about 50dB of decay.  The room has an 8' ceiling, 14' 3" wide with an open back that has 3 different depths and a right back corner that opens into the rest of the house.  Left wall is all 6' tall glass windows and the right wall is drywall.  Not the ideal listening room, but it is, what it is.


emailtim

Re: This weeks episode is about line sources.
« Reply #16 on: 30 Sep 2019, 06:22 pm »
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Danny Richie

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Re: This weeks episode is about line sources.
« Reply #17 on: 30 Sep 2019, 07:05 pm »
Quote
Thanks Danny, but I would still like to see the waterfall of the Neo10/3 line sources in an actual listening room, not an anechoic chamber.


You can't really tell anything from an in-room water fall plot. It can be made to look great or horrible just by changing the volume.

emailtim

Re: This weeks episode is about line sources.
« Reply #18 on: 30 Sep 2019, 07:15 pm »


You can't really tell anything from an in-room water fall plot. It can be made to look great or horrible just by changing the volume.

You can't tell what a line source plot looks like from a point source plot, but that is what you offered in response to my original request for the line source. 

Danny, I am not trying to be difficult here.  I am trying to see what might happen if I replace my Maggie Midranges with NEOs.

Again, I don't know of anyone who listens to their speakers in an anechoic chamber, let alone has ever been in one.  The reality is, they listen to their rigs in their actual residential rooms.

Danny Richie

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Re: This weeks episode is about line sources.
« Reply #19 on: 30 Sep 2019, 07:46 pm »
You can't tell what a line source plot looks like from a point source plot, but that is what you offered in response to my original request for the line source. 

Danny, I am not trying to be difficult here.  I am trying to see what might happen if I replace my Maggie Midranges with NEOs.

Again, I don't know of anyone who listens to their speakers in an anechoic chamber, let alone has ever been in one.  The reality is, they listen to their rigs in their actual residential rooms.

Well, the measurements of the point source Neo 10 and Neo 3 that I linked will show just how fast the drivers are at settling. A line of them will be no different. Actually playing to the same SPL level the line is even faster due to a reduced SPL output per driver. And they are probably faster than any other drivers out there including the Maggies. These have a much higher field strength with Neodymium magnets on both sides. The diaphragms are also very light weight and very tight. The Maggies have a motor structure or magnet system on one side only. The diaphragms are heavier, and not tensioned as tight. So they will not settle as fast. Oh, and the Neo 10's don't play as low. So they aren't being forced to move as far to begin with.

I don't want to be difficult here either, but I can't get or give you any meaningful data about the spectral decay of a speaker from a signal that generated from a room response. That type of spectral decay will tell you far more about your room than the speaker. Room reflections take MUCH longer to dissipate than the time that it takes for the drivers to settle.

And there are quite a few other advantages in going with the Neo's over the Maggies. The impedance load is easier to drive. The sensitivity is MUCH higher and even single digit tube amps can be used to drive them to high levels. The baffle is also smaller and imaging is better. Dynamics are higher. Even the maximum SPL levels are a lot higher.