Line array speakers, What's to like? To dislike?

[phaedrus]

You might check out Roger Russell's line array speakers:

Roger Russell IDS Speakers

He had written a couple of articles on them in Audio XPress, detailing how to build them. One was in November 2005 and the second was February, 2006 (I think). Anyway, his original variant was seriously inexpensive; if I recall correctly his total expense for drivers, cabinet, etc. was only $400 or so. And, given he was the Director of Acoustic Research at McIntosh, I suspect he knows what he's talking about.

David

 

[dnewma04]

Roger has never given an explanation of how he counteracts comb filtering effects, whether thats via EQ or very narrow directivity speakers or some other method matters not to me. So far, the best explanation I can find is "there are bigger problems with most speakers than comb filtering" which can't possibly be coming from Roger directly, because as mentioned he is one of the most knowledgeable guys in the world of audio and one of the great voices of sensibility in a world of wackos.

I take back that, his FAQ now shows how he does it...

10. Why is an equalizer required?

The response of the drivers is unusually smooth and extended. However, they do not cover the entire frequency range uniformly. The system by itself cannot deliver deep bass. However, by boosting the bass using the equalizer, bass can be extended to below 25 Hz. In the same way, the equalizer can extend the highs to 20 kHz and compensate for losses when the drivers are arranged in a column. The equalizer is carefully tailored to exactly complement the drivers in the column arrangement.

 

[dnewma04]

Don't get me wrong here, Line arrays are some of my very favorite designs, but they do have some drawbacks that must be addressed. One of my favorite speakers ever used the BG75 mentioned earlier with 4 15" driver per side in a dipole speaker.

 

[Puunda]

I've never had the chance to listen to a pair of line arrays, but from what I've read about them, I like them - for all the reasons explained above, plus the fact they will play much louder, and floor/ceiling bounce is greatly reduced. And I like my music loud. My main problem with line arrays is simply the cost. You have to have so many drivers and such a huge cabinet to make it work.

 

[mhardy6647]

Line arrays are great at long distances, but weird close up IME. Comb filtering is part of the problem but so, at least in some designs I think, is the series-parallel wiring of drivers which puts VC inductances in series. I assume the gigabuck arrays for consumer use avoid this with outrageous crossover topologies

Curved line arrays have promise for nearfield.

Bessel arrays are also worthy of consideration. http://www.angelfire.com/sd/paulkemble/soundf.html

Dig around at www.fullrangedriver.com (especially the old forum archives) for lots and lots on line arrays (typically, of fullrange drivers... duh).

 

[auplater]

weirdness in line a

Line arrays are great at long distances, but weird close up IME. Comb filtering is part of the problem but so, at least in some designs I think, is the series-parallel wiring of drivers which puts VC inductances in series. I assume the gigabuck arrays for consumer use avoid this with outrageous crossover topologies

Curved line arrays have promise for nearfield.

Bessel arrays are also worthy of consideration. http://www.angelfire.com/sd/paulkemble/soundf.html

Dig around at www.fullrangedriver.com (especially the old forum archives) for lots and lots on line arrays (typically, of fullrange drivers... duh).

Could you be a bit more specific about "weirdness" up close? Which line arrays have you heard, how they were set up, and what was "weird" about the sound?

Surely if you were within a foot or two, and the system exhibited poor driver integration with severe lobing, etc... then yes, I suppose they would sound "phasey" and "non-coherent", among other things...

OTOH... my RD75 dipoles exhibit minimal lobing (you really have to hunt and it's primarily off to the sides horizontally, much less apparent) probably due to carefully chosen xover points and power segmentation between the drivers.

What I like the most is the rock solid stable image that doesn't collapse as you move off center in the sound field... especially with female vocals, piano, solo acoustic guitar (all reasonably miked of course)

I typically listen @ ~12 feet on a sofa, but you can almost stand next to one speaker and still perceive a palpable image with only some degradation...

Of course, ymmv...

cheers

auplater

 

[Cosmos]

True... or you can use one main driver (planar) and avoid the problem... not that it's a big problem though...

Total cost of this DIY project ~~$800 / speaker

and do they ever image... you can walk around the room and the highly accurate image stays put... walking between the speakers from front to back is like walking through the image...just like if you were at a concert... highly recommended

My BG 75 line array dipoles...

Those look beautiful. How do you like the BG RD75? Where did you cross it at, 150-300?

Thanks

 

[mhardy6647]

Doc Bottlehead's "Straight 8" speakers and some DIY's I experimented with using the excellent PE 269-469 4" FR are the "home" arrays I've listened to the most. Others were mostly commercial/sound reinforcement.

By "close", I mean within 10 feet or so. Just a complete lack of any space or depth; very confused image.

 

[Arkay]

This thread sort of makes me sick, because it reminds me of a couple months ago when I went by the scrap-metal place and saw these long things with lots of holes all in a row, and two smashed-up cloth-covered grilles nearby, and a two baskets full of smashed-up smallish speaker parts. Without hesitation, the scrap-metal people had done what they routinely do, tearing up what came their way to separate the various materials for recycling.

Just two hours earlier, they had been virtually brand-new line-array speakers, and although I didn't see a brand name, they looked to have been good high-end ones. Had I passed by two hours earlier, I could have had them for a few dollars' "scrap" value. :sigh: :tears:

This was the same place I "rescued" two Sennheiser and two Sony headphones from one morning. Amazing (and sometimes sickening) what people just throw away in our modern world. Not just old/vintage stuff; sometimes recent or even brand-new stuff, too.

 

[auplater]

Doc Bottlehead's "Straight 8" speakers and some DIY's I experimented with using the excellent PE 269-469 4" FR are the "home" arrays I've listened to the most. Others were mostly commercial/sound reinforcement.

By "close", I mean within 10 feet or so. Just a complete lack of any space or depth; very confused image.

yeah... they probably were'nt dipoles.. never been a big fan of the "sweet sixteen" multi-driver "straight eight", set low power school of thought... that's why I went dipole pattern with minimal driver complement...

Originally I was gonna do multiple line array 7" mid bass alongside of the RD-75 in the baffle, but with just the 2 150W rms peerless mid-woofs, I get more than enough mid bass at > 108 dB @ the 12 foot listening location with rock solid image and great depth and spatiousness...

cheers

John L.

 

[mhardy6647]

yeah... they probably were'nt dipoles.. never been a big fan of the "sweet sixteen" multi-driver "straight eight", set low power school of thought... that's why I went dipole pattern with minimal driver complement...

True, but my experimental 1 x 8 arrays were OB's. Sounded good with up to 4 drivers going; "funny" with all 8. Mind you, there was no crossover nor Zobel; just a "clever" series-parallel array to get a reasonable net impedance.