[mlundy57]

Jay,

Thanks. Looks like I need to start feeding the piggy bank.

What is the footprint of the bade (L x W)?

Mike

[Captainhemo]

I'm  in  the same  boat  man.  It's hard looking  at these  things  knowing I'm  not  going  to get  to   fire them  up.
Approx 24x24,  no  more than  that,  just  a bit  less actually but remember,   it's just  the tips of the legs  that  reach  out  like that, a sub could easily be positioned  a bit closer if you  arranged it so it fint into the open   area of  the base.   the tips of the legs  are only  about  6"   out from   either  side of the cabinet.

jay

[studley]

When it comes to speaker design the received wisdom is that you shouldn’t put two drivers next to one another in the horizontal plane because of the inevitable lobing problem and the adverse effect on the off-axis response.  The Line Force does obviously have drivers next to one another horizontally so i’m interested to hear what Danny has to say about this.  Please note that this is not an attempt to trash this speaker- it is a perfectly reasonable question given that lobing is a well established problem and so I am genuinely interested in Danny’s response.

[nickd]

While I’m sure Danny can get technical on lobing and it’s related line source theory.

One thing I know for sure. “Received wisdom” has created a lot of poor sounding loudspeakers over the years.
There has to be open minded experimentations for a design to reach new levels of realism. I learned that 35 years ago. I was listening to systems that the reviews said should be poor because of mesurements etc.

It was only true some of the time. Tubes sounded good even though I was supposed to hate them because of noise and distortion. Old school paper drivers generally sounded better than polypropylene despite the high tech marketing.

First time I heard the Ephipany 21/21 in my room, I knew I had been lied to by people who had never heard a good line source design. The resolution and imaging has yet to be surpassed in my room. They were just HUGE, and needed really good subs to hit their potential.

Not sure about the math or measurements, but trust your ears and always reserve judgement until you hear a new design.

I just discovered horns a few years ago because I heard some bad ones and believed the bad press that was generated by poor designs. I have new respect for them after actually owning a few pairs of good horn loaded designs now. Like live microphone feed in my room. Hard to get that from regular cones.

Wouldn’t have believed it until I heard it for myself.
Worth a plane ticket to RMAF and other opportunities to hear some of this exotic gear in person. 

[studley]

While I’m sure Danny can get technical on lobing and it’s related line source theory.

One thing I know for sure. “Received wisdom” has created a lot of poor sounding loudspeakers over the years.
There has to be open minded experimentations for a design to reach new levels of realism. I learned that 35 years ago. I was listening to systems that the reviews said should be poor because of mesurements etc.

It was only true some of the time. Tubes sounded good even though I was supposed to hate them because of noise and distortion. Old school paper drivers generally sounded better than polypropylene despite the high tech marketing.

First time I heard the Ephipany 21/21 in my room, I knew I had been lied to by people who had never heard a good line source design. The resolution and imaging has yet to be surpassed in my room. They were just HUGE, and needed really good subs to hit their potential.

Not sure about the math or measurements, but trust your ears and always reserve judgement until you hear a new design.

I just discovered horns a few years ago because I heard some bad ones and believed the bad press that was generated by poor designs. I have new respect for them after actually owning a few pairs of good horn loaded designs now. Like live microphone feed in my room. Hard to get that from regular cones.

Wouldn’t have believed it until I heard it for myself.
Worth a plane ticket to RMAF and other opportunities to hear some of this exotic gear in person. 

I will never have an opportunity to hear these speakers before deciding to buy them.

It’s a scientific fact that lobing messes with the off axis response and any competent speaker designer knows that - The MTM configuration is used by many because it is an effective way of combating it.   Why is the off axis response important?  The answer is in Toole’s book.

[david45]

I will never have an opportunity to hear these speakers before deciding to buy them.

It’s a scientific fact that lobing messes with the off axis response and any competent speaker designer knows that - The MTM configuration is used by many because it is an effective way of combating it.   Why is the off axis response important?  The answer is in Toole’s book.

Don't you worry, Danny is going to have a detailed answer for you. If there's one thing I've learned he cares about as opposed to many manufacturers, it's the off axis response. And the list goes on.... 

[MHL]

When it comes to speaker design the received wisdom is that you shouldn’t put two drivers next to one another in the horizontal plane because of the inevitable lobing problem and the adverse effect on the off-axis response.  The Line Force does obviously have drivers next to one another horizontally so i’m interested to hear what Danny has to say about this.  Please note that this is not an attempt to trash this speaker- it is a perfectly reasonable question given that lobing is a well established problem and so I am genuinely interested in Danny’s response.

The Holy Grail for many is the Infinity IRS.  That has been a standard of greatness for over 30 plus years.  It has a similar driver arrangement.  I have never heard any serious disparagement against it before.

[gab]

When it comes to speaker design the received wisdom is that you shouldn’t put two drivers next to one another in the horizontal plane because of the inevitable lobing problem and the adverse effect on the off-axis response.  The Line Force does obviously have drivers next to one another horizontally so i’m interested to hear what Danny has to say about this.  Please note that this is not an attempt to trash this speaker- it is a perfectly reasonable question given that lobing is a well established problem and so I am genuinely interested in Danny’s response.

Not Danny but while we await his response, read this if you haven't already

https://audioroundtable.com/misc/nflawp.pdf

[Danny Richie]

When it comes to speaker design the received wisdom is that you shouldn’t put two drivers next to one another in the horizontal plane because of the inevitable lobing problem and the adverse effect on the off-axis response.  The Line Force does obviously have drivers next to one another horizontally so i’m interested to hear what Danny has to say about this.  Please note that this is not an attempt to trash this speaker- it is a perfectly reasonable question given that lobing is a well established problem and so I am genuinely interested in Danny’s response.

Yes, this is a problem with a lot of line source designs, but not with mine.

The problem is that as you move left or right there is a time delay that changes between the two lines. One is delayed in time verses the other. And when one starts arriving with enough phase rotation then it starts cancelling the output and leaving a hole in the response. And a 180 degree phase rotation equals a 15db dip in the response and very uneven room responses.

The amount of cancellation per degree of off axis is easily a product of two things. It depends on the acoustic center spacing and crossover point. The greater the distance of the acoustic centers or the higher the crossover point the greater the problem.

So a typical 6.5" woofer to a line or ribbons will have an acoustic center spacing of about 7" and a crossover point in the 2.5kHz range. This will cause out of phase cancellations that can easily get sever. And if you don't know how to shift the phase using the filter design you can get a much deeper hole on one side than the other. Or you can get a pretty good dip in both directions.

And a 2.5kHz wavelength is about 5.5".

But as the crossover points drop much lower it becomes much less of an issue.   

A 1kHz crossover point as used in our LS-6 line source was a wavelength of about 13". And the acoustic center spacing is 5.5".

Here are the off axis measurements. Red is on axis and each color going from red, to orange, to yellow, to green, and blue represent another 10 degrees off axis. This one is towards the tweeter side.



And towards the woofer side.



In this direction we are barely seeing a slight dip in the 1.5kHz range. Not bad at all though. It's really good actually.

And with the Serenity Line force design the acoustic centers are only 4" apart. So the off axis cancellation becomes even less of an issue.

[Danny Richie]

And I always look at off axis measurements and how speakers load the room. I didn't save the ones for the Line Forces in a file that I have here, but they looked really good.

By the way, here is a link showing how I measure. http://www.stereomojo.com/Small%20Speaker%20Shootout%202007/StereomojoSmallSpeakerShootout2007Measurements.htm

It is interesting to look at all the speakers in the shoot out and their off axis measurements, especially the vertical off axis measurements. And not surprisingly the speaker with the best off axis measurements was also the speaker with the most preferred sound.

[Danny Richie]

I will never have an opportunity to hear these speakers before deciding to buy them.

It’s a scientific fact that lobing messes with the off axis response and any competent speaker designer knows that - The MTM configuration is used by many because it is an effective way of combating it.   Why is the off axis response important?  The answer is in Toole’s book.

By the way, the MTM configuration doesn't really combat the cancellation in the vertical off axis. It just makes it the same in both directions.  Check out the measurements of the speakers that I posted a link to. Go to page two. One speaker was an MTM configuration, but it used a high crossover point. So check out what that did to the vertical off axis response.

Then compare that to the very next speaker below.

[Skiman]

Danny's LS9 crossover is at an even lower 850 Hz.

And I'm still enjoying them.

[studley]

Not Danny but while we await his response, read this if you haven't already

https://audioroundtable.com/misc/nflawp.pdf

Thanks for the link.

[studley]

Thanks for that Danny.  What is the crossover frequency BTW on the Line Force?

[Danny Richie]

Thanks for that Danny.  What is the crossover frequency BTW on the Line Force?

It is at about 1.8kHz using a very low order slope.

[nrenter]

I'm dying to see progress on these bad boys!

[Captainhemo]

I'm dying to see progress on these bad boys!

I posted a  few pics of the  composite  cabs on the previous  page.
They are  at the painters  ,  we've been in discussion with the customer about color and   he's got a  paint chip on the way so   should be  sprayed  soon. 
Will post  some pics  once we  have them back

jay

[RonP]

Question:

I've noticed the Neo3 being used in other builds of Danny's, but it's normally just one. Why so many in this configuration? Will having that many Neo3's overpower the treble?

thanks

[Danny Richie]

Question:

I've noticed the Neo3 being used in other builds of Danny's, but it's normally just one. Why so many in this configuration? Will having that many Neo3's overpower the treble?

thanks

This is a true line source design. So the driver arrays are equal length. It has several advantages and it does not make the treble louder. The output is very balanced.

[soundofrockets]

Was this pair completed/painted and fired up?  Results?  New pixs?