[Chops]

Eventhough I love my fairly new large open baffle loudspeakers (Usher Audio D2 clones gone open baffle), they are simply too dang large for this room, eating up way too much space in my theater/listening room. They sound great and have more than plenty of oomph with very little power. Gotta love that high efficiency!

I have always been highly interested in line arrays and have decided to finally build a pair, a large pair at that, with a large, matching center channel.

To fund this rather costly project I'm going to be selling off all five of my Usher Audio drivers AS WELL AS all three of my Altec 511B horns and 902-8 drivers. So if anyone is interested in purchasing any of these, please let me know.


Anyway, before I tell you about the drivers I'm going with, I want to explain the reason I chose the woofers. A few months back, one of my brothers bought the Dayton BR-1 6-1/2" 2-Way Monitor Kit Pair from PE when they had them on sale. I helped build the crossovers for him while he did most of everything else. To make a long story short, these little things put out the most amazing, low bass for such small speakers! In his room, they have solid output down into the mid-30's easily! And that's without any tone controls of any kind!! :bigeyes: They also have excellent midrange that's very full, clean and natural sounding.

So for the very reasons stated above, I'm 99.9% sure I am going to go with a large number of Dayton DC160-8 6-1/2" Classic Woofers, somewhere on the order of 10 drivers per channel (3 channels total). I figure that if those little kit bookshelf speakers put out that kind of bass and midrange with ONLY one driver, ten drivers in a LA should be that much better reaching down into the low-mid 20's, especially when you take into consideration the higher efficiency and lower distortion.

To finish the LA's off, I'm going to go with a bunch of the Dayton PT2C-8 Planar Tweeters, I'm thinking 5 per channel should do it.

They'll be crossed over at 2100Hz via my DCX2496 at 48dB per octave. The reason for choosing 2100Hz is because that's what those kit bookshelves of my brother's is crossed over at, and because the planar tweeters should only go to about 2kHz when used in multiples. Who knows, maybe I can get them down a little lower around 1.5kHz or so since I'll be using so many.

The enclosures will be 10x the size of the kit speakers which are 0.55cf tuned to 41Hz. So that means mine will be 5.5cf, and I'll have them tuned slightly lower to 38Hz with three 4" flared ports down near the bottom of the rear baffle.

I know these aren't the greatest drivers out there, but they aren't junk either, and I already know very well what one of these 6.5" drivers are capable of. And as it stands, just the drivers alone is going to cost me over $1k, so I really can't go with anything better than these ATM. But I feel that these two drivers should get me some pretty decent sound, and with much narrower, shallower speakers than what I have right now.

So what do you all think? Please let me know!

[pbrstreetgang]

looks like you did your homework and should be a great project. I am wondering why not the proven LS6 with gr drivers? Without the passives it would save a ton and with any kinda discount and less drivers would be about the same price in a proven cabinet?

[S Clark]

I agree that making a variation of the LS6 makes a lot more sense than using the Dayton classic (which has midrange issues, but does have very solid bass).   

[Rick Craig]

Eventhough I love my fairly new large open baffle loudspeakers (Usher Audio D2 clones gone open baffle), they are simply too dang large for this room, eating up way too much space in my theater/listening room. They sound great and have more than plenty of oomph with very little power. Gotta love that high efficiency!

I have always been highly interested in line arrays and have decided to finally build a pair, a large pair at that, with a large, matching center channel.

To fund this rather costly project I'm going to be selling off all five of my Usher Audio drivers AS WELL AS all three of my Altec 511B horns and 902-8 drivers. So if anyone is interested in purchasing any of these, please let me know.


Anyway, before I tell you about the drivers I'm going with, I want to explain the reason I chose the woofers. A few months back, one of my brothers bought the Dayton BR-1 6-1/2" 2-Way Monitor Kit Pair from PE when they had them on sale. I helped build the crossovers for him while he did most of everything else. To make a long story short, these little things put out the most amazing, low bass for such small speakers! In his room, they have solid output down into the mid-30's easily! And that's without any tone controls of any kind!! :bigeyes: They also have excellent midrange that's very full, clean and natural sounding.

So for the very reasons stated above, I'm 99.9% sure I am going to go with a large number of Dayton DC160-8 6-1/2" Classic Woofers, somewhere on the order of 10 drivers per channel (3 channels total). I figure that if those little kit bookshelf speakers put out that kind of bass and midrange with ONLY one driver, ten drivers in a LA should be that much better reaching down into the low-mid 20's, especially when you take into consideration the higher efficiency and lower distortion.

To finish the LA's off, I'm going to go with a bunch of the Dayton PT2C-8 Planar Tweeters, I'm thinking 5 per channel should do it.

They'll be crossed over at 2100Hz via my DCX2496 at 48dB per octave. The reason for choosing 2100Hz is because that's what those kit bookshelves of my brother's is crossed over at, and because the planar tweeters should only go to about 2kHz when used in multiples. Who knows, maybe I can get them down a little lower around 1.5kHz or so since I'll be using so many.

The enclosures will be 10x the size of the kit speakers which are 0.55cf tuned to 41Hz. So that means mine will be 5.5cf, and I'll have them tuned slightly lower to 38Hz with three 4" flared ports down near the bottom of the rear baffle.

I know these aren't the greatest drivers out there, but they aren't junk either, and I already know very well what one of these 6.5" drivers are capable of. And as it stands, just the drivers alone is going to cost me over $1k, so I really can't go with anything better than these ATM. But I feel that these two drivers should get me some pretty decent sound, and with much narrower, shallower speakers than what I have right now.

So what do you all think? Please let me know!

The Dayton woofer isn't a good choice for use with the PT2 planars. You'll need a smaller diameter woofer that can cross higher in an array. If you plan to run the arrays full-range there are some 5" woofers that will give you decent bass extension. The DCX gives you quite a bit of flexibility so that's a good thing. I have some new BG planars on the way for testing but I'm not sure what the price will be or when production units will become available.

One thing I forgot to mention - adding more tweeters doesn't mean that you can have a lower crossover point. You increase the thermal capability with multiple drivers (reduce non-linear distortion) but the fundamental resonance of the planar remains the same regardless of the amount of drivers. That resonance defines where you locate the crossover point so there's a limit as to how low you can go, even with a 48db slope. This is a common misconception and I've seen other commercial array designs that make the same mistake.

[Chops]

looks like you did your homework and should be a great project. I am wondering why not the proven LS6 with gr drivers? Without the passives it would save a ton and with any kinda discount and less drivers would be about the same price in a proven cabinet?

I agree that making a variation of the LS6 makes a lot more sense than using the Dayton classic (which has midrange issues, but does have very solid bass).  

Thanks. I have done my homework some. I just know the basics. I still have a lot to learn before I actually start the project. As both of you have stated, going with the stripped-down LS6 would be a great idea IF I could get 3 of them for about the price I'm looking at for my current Dayton driver idea. Remember, I am going to be building 3 of them (L/C/R). Also, I don't know about you, but I do not see the LS6 kits on GR's site, nore do I know if the drivers offered on GR's site are the exact ones used in the LS6's.

Also, I know the Dayton Classics have midrange issues, but IIRC, those issues come into play around 3.5kHz. I would be cutting them off around 2-2.1kHz sharply at 48dB per octave.

[Chops]

The Dayton woofer isn't a good choice for use with the PT2 planars. You'll need a smaller diameter woofer that can cross higher in an array. If you plan to run the arrays full-range there are some 5" woofers that will give you decent bass extension. The DCX gives you quite a bit of flexibility so that's a good thing. I have some new BG planars on the way for testing but I'm not sure what the price will be or when production units will become available.

One thing I forgot to mention - adding more tweeters doesn't mean that you can have a lower crossover point. You increase the thermal capability with multiple drivers (reduce non-linear distortion) but the fundamental resonance of the planar remains the same regardless of the amount of drivers. That resonance defines where you locate the crossover point so there's a limit as to how low you can go, even with a 48db slope. This is a common misconception and I've seen other commercial array designs that make the same mistake.

Hi Rick. I planned on crossing the woofers over at 2-2.1kHz which is where they are crossed over in the bookshelves. They sound very good actually. I don't know if having them in a LA requires a higher xover point, and if so, why. And what I meant with the xover point with the planars is that in the PE cataloge it states that those planars can be crossed over as low as 2kHz when used in multiples, but 2.5kHz if just a single driver used. I guess I was biting off a little more than I could chew in saying that they could possibly go lower to 1.5kHz.

And yes, I do want to run these fullrange. Not for movies, but for music. I listen to a lot of pipe organ and classical (as well as others), so I would really like these to go as low as possible on their own without the help of subs. When movies are played, I'll have the subs on and the mains and center crossed over at 50Hz.

[Daygloworange]

And what I meant with the xover point with the planars is that in the PE cataloge it states that those planars can be crossed over as low as 2kHz when used in multiples, but 2.5kHz if just a single driver used. I guess I was biting off a little more than I could chew in saying that they could possibly go lower to 1.5kHz.

Chops,

I'm not sure what the Dayton planars are fully capable of, but I would continue doing research before settling on a crossover point in the 2K range.

While Rick Craig is of the opinion that you can't get a very low crossover point with a line of planars, I've seen and heard it well implemented with lines of BG Neo 8's.

Crossover point of 1000 Hz for a line of (6)Neo 8's, and crossover point of 850 Hz for a line of (9) Neo8's.

I listen to a lot of pipe organ and classical (as well as others), so I would really like these to go as low as possible on their own without the help of subs.

With the right woofer in a line source and a ported design, you can get it to play into the 20's.

Cheers

[Rick Craig]

The Dayton woofer isn't a good choice for use with the PT2 planars. You'll need a smaller diameter woofer that can cross higher in an array. If you plan to run the arrays full-range there are some 5" woofers that will give you decent bass extension. The DCX gives you quite a bit of flexibility so that's a good thing. I have some new BG planars on the way for testing but I'm not sure what the price will be or when production units will become available.

One thing I forgot to mention - adding more tweeters doesn't mean that you can have a lower crossover point. You increase the thermal capability with multiple drivers (reduce non-linear distortion) but the fundamental resonance of the planar remains the same regardless of the amount of drivers. That resonance defines where you locate the crossover point so there's a limit as to how low you can go, even with a 48db slope. This is a common misconception and I've seen other commercial array designs that make the same mistake.

Hi Rick. I planned on crossing the woofers over at 2-2.1kHz which is where they are crossed over in the bookshelves. They sound very good actually. I don't know if having them in a LA requires a higher xover point, and if so, why. And what I meant with the xover point with the planars is that in the PE cataloge it states that those planars can be crossed over as low as 2kHz when used in multiples, but 2.5kHz if just a single driver used. I guess I was biting off a little more than I could chew in saying that they could possibly go lower to 1.5kHz.

And yes, I do want to run these fullrange. Not for movies, but for music. I listen to a lot of pipe organ and classical (as well as others), so I would really like these to go as low as possible on their own without the help of subs. When movies are played, I'll have the subs on and the mains and center crossed over at 50Hz.

The driver C-T-C spacing of the 6" woofers is the problem and because of that the planar would have to be crossed lower. With the PT2 you really cannot go  low enough to make a smooth transition over to the woofers.

[Chops]

The driver C-T-C spacing of the 6" woofers is the problem and because of that the planar would have to be crossed lower. With the PT2 you really cannot go  low enough to make a smooth transition over to the woofers.

So what's the max xover point for a line of 6.5" drivers? C-T-C spacing for the Dayton drivers should be right at 6.5", maybe a hair-bit more.

[Rick Craig]

The driver C-T-C spacing of the 6" woofers is the problem and because of that the planar would have to be crossed lower. With the PT2 you really cannot go  low enough to make a smooth transition over to the woofers.

So what's the max xover point for a line of 6.5" drivers? C-T-C spacing for the Dayton drivers should be right at 6.5", maybe a hair-bit more.

It depends not only on the driver diameter but also the response (off-axis and off-axis). Typically it's 2K or below.

[Rick Craig]

And what I meant with the xover point with the planars is that in the PE cataloge it states that those planars can be crossed over as low as 2kHz when used in multiples, but 2.5kHz if just a single driver used. I guess I was biting off a little more than I could chew in saying that they could possibly go lower to 1.5kHz.

Chops,

I'm not sure what the Dayton planars are fully capable of, but I would continue doing research before settling on a crossover point in the 2K range.

While Rick Craig is of the opinion that you can't get a very low crossover point with a line of planars, I've seen and heard it well implemented with lines of BG Neo 8's.

Crossover point of 1000 Hz for a line of (6)Neo 8's, and crossover point of 850 Hz for a line of (9) Neo8's.

I listen to a lot of pipe organ and classical (as well as others), so I would really like these to go as low as possible on their own without the help of subs.

With the right woofer in a line source and a ported design, you can get it to play into the 20's.

Cheers

You missquoted me. I've worked with the planars in question and know what they are capable of. I'm just trying to help someone avoid buying the wrong drivers to use with them.

The amount of drivers has no bearing on how low a planar should be crossed. The resonance is the same regardless whether you have 1 or 100 of them and the resulting distortion will help define the best place to cross them. The same acoustic principles apply to the low frequency extension for 1 or 100 woofers. Making a claim that a 6-7" woofer in a 2-way array will have 20's extension comparable to say a 10" or 12" driver is misleading and utter BS.

[Chops]

The same acoustic principles apply to the low frequency extension for 1 or 100 woofers. Making a claim that a 6-7" woofer in a 2-way array will have 20's extension comparable to say a 10" or 12" driver is misleading and utter BS.

Apparently not according to owners and reviewers of the GR LS-6, reporting in-room measurements down into the high teens.

[Daygloworange]

This is really interesting....

The amount of drivers has no bearing on how low a planar should be crossed. The resonance is the same regardless whether you have 1 or 100 of them and the resulting distortion will help define the best place to cross them.

Really??  The amount of drivers used has no bearing on crossover point and how far down in output the distortion is? Are you kidding me?   

The same acoustic principles apply to the low frequency extension for 1 or 100 woofers.

Really??  Physics tells us that even a 3" driver will play (say) 20 Hz. It will do so with less distortion than a large woofer. It just won't have any output because it's not displacing enough air through surface area and excursion. Add 100 of those same 3" drivers, you add surface area, without having to increase excursion (keeping distortion low), and suddenly you are increasing the output at 20 Hz.

I call that adding low frequency extension . By increasing the number of drivers, you have more surface area, therefore more output at any given frequency. It's not even rocket science.

You missquoted me.

I fail to see where.

I've worked with the planars in question and know what they are capable of. I'm just trying to help someone avoid buying the wrong drivers to use with them.

No, it's a thinly veiled attempt to bash. Your intent is to claim it's a misconception that you can cross over to a planar at a low frequency, and that it is a mistake.

Making a claim that a 6-7" woofer in a 2-way array will have 20's extension comparable to say a 10" or 12" driver is misleading and utter BS.

Really??  How many 6" or 7" woofers would it take to equal the surface area of a 10" or 12" woofer?

We've been over this:

http://www.audiocircle.com/index.php?topic=45051.20

Rick, you've clearly got LS-6 and LS-9 envy. You call what it is capable of, utter BS.

I can't believe you'd actually post that.   If I were you, I would merely say that you don't think it's possible. That way you'd have some wiggle room. Now you don't.

You claim it's not possible to get extension into the 20's with a 6" or 7" woofer.

That would make Danny a fraud, and all the experienced audiophiles who have heard the speaker and claimed it will play in the 20's and lower, delusion, and a fraud as well.

How sure are you of yourself?

I can tell you, I've had the LS-9 designed line arrays right next to my PR subwoofer that will play flat to 25Hz(in room), and run a recording I engineered that has frequencies into the low teens, and possibly lower, and I can tell you for sure that they will play lower than 20Hz.

Do you want to call me a liar?

As it stands now, your positions are meaningless. You haven't even heard the LS line arrays and what is possible. If you did, you wouldn't be talking.

Why didn't you go to hear the LS-6's and LS-9's when you were at RMAF 2007 and hear for yourself?

Why didn't you prove it to yourself first, whether they are capable or not?

I can post reviews of the LS series line arrays, would you like to explain to those experienced audiophiles how full of BS they are?

Cheers

[pbrstreetgang]

I dont know how to look at the fuzzy math used to say the LS9s wont play low and loud. All I know is that when putting them through their paces MYSELF in a large room they absolutely have low bass performance with PLENTY of output with a coherence better than any subwoofer augmented systems that I have heard. I suspect for those that have personally heard them serious questions are raised when someone tells them what they know to be true and have experienced is wrong.

[KCI-JohnP]

The same acoustic principles apply to the low frequency extension for 1 or 100 woofers. Making a claim that a 6-7" woofer in a 2-way array will have 20's extension comparable to say a 10" or 12" driver is misleading and utter BS.

Rick,
I have spent some time with both the GR LS-6 and the LS-9's and I can tell you that both of those speakers dip down into the 20's and there's no doubt about it. I believe that someone measured Art S.'s LS-6's and if I remember correctly they dipped down into the high teens. Rather than continuing
to insist that Danny's speakers are incapable of doing this why don't you just give them a listen....that'll end it right there.

John

[S Clark]

I will be building a LS9 kit as the spring gets here.  I will not not be using a sub.

[JohnR]

I've worked with the planars in question and know what they are capable of. I'm just trying to help someone avoid buying the wrong drivers to use with them.

No, it's a thinly veiled attempt to bash. Your intent is to claim it's a misconception that you can cross over to a planar at a low frequency, and that it is a mistake.

He was refering specifically to the driver that the original poster asked about, not to any other.

Denny, your attempts here to goad Rick are noted, and not appreciated. If you continue with this, your account will be disabled.

[pbrstreetgang]

He was refering specifically to the driver that the original poster asked about, not to any other.

Denny, your attempts here to goad Rick are noted, and not appreciated. If you continue with this, your account will be disabled.

[quote Rick] That resonance defines where you locate the crossover point so there's a limit as to how low you can go, even with a 48db slope. This is a common misconception and I've seen other commercial array designs that make the same mistake.[/quote]

[quote Rick] The resonance is the same regardless whether you have 1 or 100 of them and the resulting distortion will help define the best place to cross them. The same acoustic principles apply to the low frequency extension for 1 or 100 woofers. Making a claim that a 6-7" woofer in a 2-way array will have 20's extension comparable to say a 10" or 12" driver is misleading and utter BS.[/quote]

To be fair those two comments had NOTHING to do with the original question and is ancillary to the OP questions. There might be some Goading but it is not one sided. One could even say that it flies in the face of actuality as it is successfully done by multiple other OEMs, so in addition to it being ancillary to the OP questions it is nicely packaged goading in its own rite.

[Chops]

Okay everyone, I don't want this thread turning into an ugly monster that will eventually be locked and/or shut down. Let's please make peace and get back to the matter at hand. 


Anyway, I think I might have figured out a solution to this project...

First off, I'm going to scrap the entire idea of building the LA's with the Dayton Classic drivers. Not only are they too large, but they also have those midrange issues and will not match up to the Dayton planars properly.


So what I think I will do now is this...

I will buy a total of (20) GR M-130 drivers and a total of (15) Dayton PT2C-8 planars. The left and right channels will each have EIGHT woofers and SIX planars, the center channel will be exactly half with FOUR woofers and THREE planars.

This will keep me in budget (just over $1k for drivers alone), will provide better performance due to the better quality woofers, they are smaller and their C-T-C will be closer allowing for a higher xover freq to match up with the planars (2kHz), will be a nominal 4 ohms for the main channels (nominal 8 ohms for the center channel), the main channels will probably extend down into the mid-30's pretty well, and will be like the smaller, cheaper baby brother of the GR LS-6. 

From the looks of the plot on GR's website for the M-130, even off axis, a 2kHz xover point looks to be well within reach as the driver seems to flat at 2kHz. Since if I am staying with the Dayton planars due to their price and performance, I am stuck with a minimum xover point of 2kHz and from what I gather, C-T-C spacing with 5.25" drivers at this freq shouldn't be an issue anymore.

So what do you all think about this idea? Am I finally on the right track this time?

[S Clark]

This should work reasonably well for you.  I believe that the standard M130 is what Danny used in his first line array, the Alpha series.  You should be able to reach you goals of extending into the 30's without too much problem.  Best of luck with the project