Line array question

[kgveteran]

What would be the smallest woofer i could use and still get musical bass.This is for music in my living room.I would like them to be about 6' tall and rather thin.

I've been looking at the DOTD at PE for woofers and tweeters.Any suggestions.

This would be for "Fill the room" type listening, not head in a vise audio only :B .

[Mazeroth]

Define "musical bass"? Also, will these be crossed to a subwoofer or will these take care of all the octaves?

As far as the tweeters go you're only real viable options are to go with the Dayton PT2B (which isn't very good in the distortion department) or spend 4x as much and go with a Fountek ribbon tweeter array, that is if you want to keep the arrays under $3000. Both will need to be crossed over above 2khz to minimize distortion which will limit the size of the woofer you can use. Jim Griffin's white paper states that the longest your center-to-center spacing should be is a single wavelength. For 5.25" that's 2582 hz, where 2x that (5164 hz) you'll start to get severe cancellations. However, recently I read a post by Jim stating that his white paper was incorrect and that the ctc spacing should be 1/2 wavelength, which is asking for a lot! If you did that with a line of ribbons or planars you're pretty much stuck using a small, 3-4" driver. With that, it's hard to recommend a woofer that will get the job done if you want to take Jim's newest comments and apply them to your array. I've always been fond the of RS150s and with their ctc spacing you should be able to keep the ctc criteria to around 2000hz. Stepping up to the RS180s opens up a whole new can of worms. Rick Craig does have an array that uses RS180s that cross to the Fountek 2.0 ribbons so it can be done, but I'm not sure what kind of sacrafices you'll be making.

[Rudy Jakubin]

Something like this maybe??
10 - DA135's

https://www.parts-express.com/Dayton-Audio-DA135-8-5-1-4-Aluminum-Cone-Woofer-295-330?quantity=1

6 Dayton Planars

https://www.parts-express.com/Dayton-Audio-PT2C-8-Planar-Tweeter-275-085?quantity=1

Plenty of bass here and no subwoofer, even for HT...

[Jim Holtz]

Define "musical bass"? Also, will these be crossed to a subwoofer or will these take care of all the octaves?

As far as the tweeters go you're only real viable options are to go with the Dayton PT2B (which isn't very good in the distortion department) or spend 4x as much and go with a Fountek ribbon tweeter array, that is if you want to keep the arrays under $3000. Both will need to be crossed over above 2khz to minimize distortion which will limit the size of the woofer you can use. Jim Griffin's white paper states that the longest your center-to-center spacing should be is a single wavelength. For 5.25" that's 2582 hz, where 2x that (5164 hz) you'll start to get severe cancellations. However, recently I read a post by Jim stating that his white paper was incorrect and that the ctc spacing should be 1/2 wavelength, which is asking for a lot! If you did that with a line of ribbons or planars you're pretty much stuck using a small, 3-4" driver. With that, it's hard to recommend a woofer that will get the job done if you want to take Jim's newest comments and apply them to your array. I've always been fond the of RS150s and with their ctc spacing you should be able to keep the ctc criteria to around 2000hz. Stepping up to the RS180s opens up a whole new can of worms. Rick Craig does have an array that uses RS180s that cross to the Fountek 2.0 ribbons so it can be done, but I'm not sure what kind of sacrafices you'll be making.

Some thoughts. I think what Jim meant with his comment is that in an "ideal" situation 1/2 wave length would be perfect. However, adhering to a one wave length standard pushes any comb filtering effects well above 10K which then becomes inaudible.

When I built mine, I spaced the woofers with the frames nearly touching and the ribbons very, very close to the woofer line. I have yet to hear any issues with comb filtering or have anyone comment on a lack of dispersion in the top octaves. Quite the opposite actually.

The RS180's and Fountek NeoCD2.0's work very well in a line array. The extremely low demands that are placed on the ribbons allow them to be crossed much lower than normal which again pushes any comb filtering out of the audibility range.

Jim did his homework and then some coming up with the guidlines for building a home line array. A lot of designers calculate, model and declare it won't work or that you can only listen at one distance etc. In practice, that is simply not the case. I've had vigorous discussions on this board trying to explain it with out success. ops: The reality is, you need to listen to a line array based on Jim's later work to understand. That said, the early Linus designs were a budget design prototype if you will. They sound nothing like the designs Rick and Jim are offering today.

The Dayton planars will work fine with a small more budget oriented driver. Crossover has to be as low as possible to meet the comb filtering issue but above 2K for the planar. A real balancing act with that driver. I heard the last prototype Jim and Rick created in 2003 at Dayton when Jim had a room set up during PE's DIY event. That was what pushed me to build a line array. It sounded very good for a budget array.

However, Rick has stated that from a pure sound quality perspective the same money it costs to build an inexpensive line array will build a better sounding 3-way less near field listening, exceptional dynamics etc. Again, there are trade offs.

I've not heard the DA175's in an array. They make darn nice budget bass drivers in a 3-way. The 2-ways I've heard using them did not have great mids. The Rs150's would be much better but more expensive.

HTH

Jim

[Rick Craig]

What would be the smallest woofer i could use and still get musical bass.This is for music in my living room.I would like them to be about 6' tall and rather thin.

I've been looking at the DOTD at PE for woofers and tweeters.Any suggestions.

This would be for "Fill the room" type listening, not head in a vise audio only :B .

What kind of bass extension are you looking for?

[Scott Simonian]

How does that dayton tower sound? If I wanted to purchase those drivers for a front pair...where could I find the info to build the x-over?

[gonar]

hey jim, is there a project thread anywhere on the line array in your avatar?

[Jim Holtz]

hey jim, is there a project thread anywhere on the line array in your avatar?

It's a custom design by Selah Audio. Rick can answer all of your questions about it. I've had them for about 3 years and they still put a big smile on my face when I listen to music or watch a movie. Incredible dynamics!

Jim

[cjd]

Aagh. my reply disappeared. :|

Anyhow. I was trying to say, I too think the RS150 would work really well. RS180 is a great driver but I think you gain maybe 2-3Hz on the bottom (35-36Hz tuning ported vs ~38Hz tuning) but lose 300Hz and probably some slope steepness flexibility on top. Trim the frames a bit on either and you can snug 'em up closer. Pair with a nice Fountek ribbon line (NeoCD2 would work superbly I think...) and you'd be in great shape. Well, as long as the cost isn't problematic.

C

[crackyflipside]

You know we need a line-array project in the mission accomplished forum.

Evil Twin, Jon, Thomas; anybody listen to our cries!

[Danse]

You know we need a line-array project in the mission accomplished forum.

Evil Twin, Jon, Thomas; anybody listen to our cries!

I don't mind making a Needle type array using 16 Hivi B3N if some people are willing to help out. Especially Xover help. I currently built a pair with 14 B3N and will be updating them to 16 B3N per side. The current tweeter is a Fountek Neocd3, but I don't mind changing it to any other 4 1/8'' tweeter and open to suggestions.

I anybody is interested I'll post the current cabinet drawings.

This would not be a true Line array, and would be for sitting hight listening, but would not be that expensive to build.

Robert

[cjd]

bah. B3n. not worth it IMO.

[engr_dave]

OK then, Chris...

I could be talked into building an array with RS150s and NeoCD2s. I like the idea of unlimited dynamic range powered by ~1KW per side Bryston 7BSSTs

I'll admit, however, that I don't know much about line array design. My feeble understanding of early reflections and non-time-aligned arrivals suggests that a line array will suffer from poor imaging since the path from the outer drivers will be longer than that from the center drivers. That's why I've been leaning doward "time aligned" WMTMW designs like Dunlavy or my own Dynaudio Myrages. But I'm sure I could be proven wrong. I'd love to hear one of Rick Craig's designs...

[ThomasW]

Evil Twin, Jon, Thomas; anybody listen to our cries!

We built line arrays decades ago, so 'the thrill is gone'....... :B

[Mazeroth]

We built line arrays decades ago, so 'the thrill is gone'....... :B

If the thrill was gone after line arrays, I'd hate to see what you guys do for thrills now! 8O :B

[Jim Holtz]

OK then, Chris...

I could be talked into building an array with RS150s and NeoCD2s. I like the idea of unlimited dynamic range powered by ~1KW per side Bryston 7BSSTs

I'll admit, however, that I don't know much about line array design. My feeble understanding of early reflections and non-time-aligned arrivals suggests that a line array will suffer from poor imaging since the path from the outer drivers will be longer than that from the center drivers. That's why I've been leaning doward "time aligned" WMTMW designs like Dunlavy or my own Dynaudio Myrages. But I'm sure I could be proven wrong. I'd love to hear one of Rick Craig's designs...

I think Fred T lives somewhere in the Southwest. He has Selah audio XT8's. Fred is a frequent flier on the array board at audioroundtable.com and is very active.

HTH

Jim

[cjd]

Thing is the B3's have a whole mess of problems... no bass response, and crossing them to tweeters is really tough in following rules for comb filtering. No tweeter and you still have the comb issues. If I were going that route I'd just build it straight B3N and live with the combing. By the time you're done you'll have more invested than the WWMTM's I've built (assuming you supplement the bottom end). Which is why I say, I'm just not sure it's worth it if you're after some sound nirvana. If you're having fun and experimenting, seeing what you can do within a constraint, it's a different project entirely and there really is no limit on what is reasonable. So don't let my grumpiness on the subject dissuade you.

I don't necessarily think RS150/NeoCD2 is any kind of ultimate. But it would probably perform rather well. And be quite a bit more expensive than a B3 line.

By time aligned, I assume you mean physically? Time is otherwise compensated for in the crossovers, at least most stuff around here.

[engr_dave]

By time aligned, I assume you mean physically? Time is otherwise compensated for in the crossovers, at least most stuff around here.

I meant physically or electrically, understanding that some designs achieve it electrically (there are some very fine "flat baffle" speakers out there) and some achieve it physically with sloped or stepped baffles. The point is that with an array, the drivers at the top of the line (for example) get the same signal as the drivers in the middle - so there's no opportunity for a crossover to "fix" the path length delay.

Again I may be missing something fundamental here. Would an ideal line array be curved with radius equal to listener distance?

[Mazeroth]

Would an ideal line array be curved with radius equal to listener distance?

Yes. The problem is that your "sweet spot" is very, very limited with this type of arrangement and is your placement and listening positions within the room.

[Jim Holtz]

I meant physically or electrically, understanding that some designs achieve it electrically (there are some very fine "flat baffle" speakers out there) and some achieve it physically with sloped or stepped baffles. The point is that with an array, the drivers at the top of the line (for example) get the same signal as the drivers in the middle - so there's no opportunity for a crossover to "fix" the path length delay.

Again I may be missing something fundamental here. Would an ideal line array be curved with radius equal to listener distance?

Power tapering is the answer and is outlined in Jim Griffins line array white paper. It is the DIY line array builders "bible". :T Curved arrays are not the answer.

HTH

Jim

[Jim Holtz]

Yes. The problem is that your "sweet spot" is very, very limited with this type of arrangement and is your placement and listening positions within the room.

Line arrays utilizing power tapering have "walk around" imaging. It creates an extremely wide "sweet spot". The center spot is still the best but you can easily move to either side and have little degradation. It's kind of eerie actually.

Jim

[Dennis H]

Power tapering is the answer and is outlined in Jim Griffins line array white paper.

Yup, make 'em act less like a line source and more like a point source. I'm sure there must be a message there somewhere....

[Jim Holtz]

Yup, make 'em act less like a line source and more like a point source. I'm sure there must be a message there somewhere....

:rofl: I expected that. Actually, power tapering brings the image to a "real size" perspective which eliminates the 6' head syndrome often comment on by "little speaker" people that have listened to incorrectly designed line arrays. :W

Man, I couldn't pass that one up.

Jim

[cjd]

You're still saying "make 'em more like a point source" Jim.

C

[Jim Holtz]

You're still saying "make 'em more like a point source" Jim.

C

Ya think??? 8O Nah.....

5'-6' tall performers, nearfield listening and incredible dynamics does not equal point source.

Jim

[cjd]

This nearfield claim is the only differentiator. But only because I choose not to sit that close. I actually *can* if I wanted to. Mine aren't 5-6 foot either, just a smidge over 4. :P

I do understand the difference, and it is there. Mostly just joking around.

[Jim Holtz]

This nearfield claim is the only differentiator. But only because I choose not to sit that close. I actually *can* if I wanted to. Mine aren't 5-6 foot either, just a smidge over 4. :P

I do understand the difference, and it is there. Mostly just joking around.

I knew you were joking around and I was too. There are enough silly arguments currently on the various audio boards. I enjoy the tight moderation and focus of this board. It has become my favorite. We don't always agree but it never gets mean spirited. I like that. kudos to Jon and Thomas! :T

Jim

[Mazeroth]

Jim, are yours power tapered? If so, what's the wiring like?

The line arrays I built with ten 5" Vifas (budget line arrays as a test) had a 3-2-2-3 power taper that worked extremely well. I was also only using a single Fountek JP-2.0 ribbon tweeter, the most a 23 year-old could afford :B

Actually, I just dug up a picture of one before I put stands on them:

Image not available

[Jim Holtz]

Jim, are yours power tapered? If so, what's the wiring like?

The line arrays I built with ten 5" Vifas (budget line arrays as a test) had a 3-2-2-3 power taper that worked extremely well. I was also only using a single Fountek JP-2.0 ribbon tweeter, the most a 23 year-old could afford :B

Actually, I just dug up a picture of one before I put stands on them:

Image not available

Hi Mezeroth,

Yes, my Omegarrays are power tapered. I built them about three years ago so I don't remember specifically the driver wiring arrangement but it did work out to be the same as the Linus II wiring if I remember correctly. I agree, it does work well.

That's a very good looking line array. Are you still listening to it? BTW, if you look in the gallery on Selah Audio's website, Rick has done an array with the RS150s and also an array with a single ribbon that was designed so others could be added as the budget permitted.

Jim

[Andy_G]

Jim, are yours power tapered? If so, what's the wiring like?

The line arrays I built with ten 5" Vifas (budget line arrays as a test) had a 3-2-2-3 power taper that worked extremely well. I was also only using a single Fountek JP-2.0 ribbon tweeter, the most a 23 year-old could afford :B

Actually, I just dug up a picture of one before I put stands on them:

Image not available

This is the BEST way to go , :T

which Vifa 5" is it? BC11??

do you run a sub as well, I found that 10 x 5" a side did not give me the bass I wanted, although mine run open back, which wouldn't help with bass response ;h

[Dennis H]

and incredible dynamics

I think that's the biggest benefit. Lots of cone area and very efficient means they can really belt it out without straining either the amp or the drivers. It's also possible to get there with big pro drivers but the cabinets tend to get pretty big (wide) to stick in most living rooms.

[Mazeroth]

This is the BEST way to go , :T

which Vifa 5" is it? BC11??

do you run a sub as well, I found that 10 x 5" a side did not give me the bass I wanted, although mine run open back, which wouldn't help with bass response ;h

Yes, they are the PE buyout BC11s.

I run them sealed with 0.5 ft3 per section of 5, crossed to my IB sub at 75hz. I could see the bass being very anemic if these were used in a dipole configuration. Heck, I even have to use a small Linkwitz-transform to boost the lowend on these to cross to my IB at 75hz, via a DCX2496. Without the lowend boost they would start dropping off around 110hz, which made the location of the IB very aparent.

[Andy_G]

Yes, they are the PE buyout BC11s.

I run them sealed with 0.5 ft3 per section of 5, crossed to my IB sub at 75hz. I could see the bass being very anemic if these were used in a dipole configuration. Heck, I even have to use a small Linkwitz-transform to boost the lowend on these to cross to my IB at 75hz, via a DCX2496. Without the lowend boost they would start dropping off around 110hz, which made the location of the IB very aparent.

Which is why I use stereo bass drivers, rather than a single sub. Mine are more a standard 3-way than a 2-way + sub. The lower x-o point is around 120. Isn't it fun seeing the different ways of solving an issue. ;-)

[Rick Craig]

Actually I'm not tapering any of the current arrays. With some driver combinations (such as ten woofers) it helps to achieve your impedance and /or sensitivity target. For the 8-9 drivers that I use now tapering isn't needed. Even if I were to use twelve 5" drivers tapering wouldn't be mandatory.

[Andy_G]

I think tapering is definitely required when you have the single tweeter like Mazeroth and I use. I feel this helps the mids blend in better with the top end because it focuses the mids toward the centre.

[cjd]

Well, yeah. You're making a line of drivers behave like the point source tweeter...

C

[Mazeroth]

Well, yeah. You're making a line of drivers behave like the point source tweeter...

C

Hello Captain Obvious!

C

[Andy_G]

Well, yeah. You're making a line of drivers behave like the point source tweeter...

C

Not really a point source. It still behaves like a shorter line array, but without the fully cylindrical wave front. Sure it is focused more in the vertical direction than a full un-taper line array, but this is probably quite a good thing because your instruments etc come from a definite height, that remains steady if you stand up. I have only heard only one un-tapered full range line array, and it didn't seem to focus well in the vertical direction. (this isn't to say one of Rick's for instance doesn't have height focus, I can only comment on the one I have heard)

[Gir]

Jim, are yours power tapered? If so, what's the wiring like?

The line arrays I built with ten 5" Vifas (budget line arrays as a test) had a 3-2-2-3 power taper that worked extremely well. I was also only using a single Fountek JP-2.0 ribbon tweeter, the most a 23 year-old could afford :B

Actually, I just dug up a picture of one before I put stands on them:

Image not available

Exactly what is meant by "3-2-2-3"? Are we talking watts here? I understand that you want to have the center speakers with the most power and tapper off towards the ends, so do you mean that the ends have 3 fewer watts going to it? Sorry for the noob question :roll:

[Andy_G]

Exactly what is meant by "3-2-2-3"? Are we talking watts here? I understand that you want to have the center speakers with the most power and tapper off towards the ends, so do you mean that the ends have 3 fewer watts going to it? Sorry for the noob question :roll:

the outer three on each end are wired in series. the inner 2 on either end are wired in series, then the whole lot wired in parallel.

so the outer 3 on either end are essentially getting 2/3 the power of the inner 4.

This also gives a nice impedance. If the driver are nominal 8ohm, you end up with 4.8ohm. If you want to look at how this works and how impedances, spl etc work out you could download this little Excel file I wrote.

http://users.tpg.com.au/users/gradds/xls_files/array%20calc%20V3.xls

[Gir]

the outer three on each end are wired in series. the inner 2 on either end are wired in series, then the whole lot wired in parallel.

so the outer 3 on either end are essentially getting 2/3 the power of the inner 4.

This also gives a nice impedance. If the driver are nominal 8ohm, you end up with 4.8ohm. If you want to look at how this works and how impedances, spl etc work out you could download this little Excel file I wrote.

http://users.tpg.com.au/users/gradds...0calc%20V3.xls

wow, that makes a lot more sense, thanks!

[Andy_G]

just watch your +/- tabs
for series wiring remember to go

x-o +ve to driver 1 +ve then
driver 1 -ve to driver 2 +ve then
driver 2 -ve to driver 3 +ve then
driver 3 -ve to x-o -ve