Are line arrays good for midbass/sub duty?

[djn]

Hi all, I have subs, mid horns, and tweets so now I am looking at bass bins. Some time ago I whipped out a pair of line arrays just for fun using 8 4" driver each side and I was floored at how good the midbass sounded.

Is this something that all Line Arrays do well or did it just work out with what I built?

I am thinking that for bass bins I might think about 4 8" drivers per side. I don't know much about LAs, so would this make a good midbass box?

PS, I know this is a subwoofer forum, but I figured it is close so I could ask here.

[bjorno]

Originally Posted by djn

Hi all, I have subs, mid horns, and tweets so now I am looking at bass bins. Some time ago I whipped out a pair of line arrays just for fun using 8 4" driver each side and I was floored at how good the midbass sounded.

Is this something that all Line Arrays do well or did it just work out with what I built?

I am thinking that for bass bins I might think about 4 8" drivers per side. I don't know much about LAs, so would this make a good midbass box?

PS, I know this is a subwoofer forum, but I figured it is close so I could ask here.

Hi djn,


Here is a reported use of small subs in short arrays:

Picture:

http://www.diyaudio.com/forums/attac...-mini-7s-2.jpg

From this thread:

Odd Woofers in these Mini 7s

b

[hum4god]

what frequency range do you want to cover ?
why not use a midbass horn like the edgar horn from 80-500hz ?
it would probably match your edgarhorn mid best .

[chris661]

To get a true line array, the array of drivers must be several times the longest wavelength you want to reproduce.

A vertical line of drivers will work, but the output won't be cylindrical like a true line array.

Quote from Rod Elliott...
"The biggest single problem is that the effective line length varies with frequency. At 10kHz, even a couple of cabinets will easily exceed a line length of 10 wavelengths (at which point the line can conceivably be considered "infinite"). At 1kHz, wavelength is 345mm, so the line must be at least 3.45 metres high to be considered close to an infinite line. At 100Hz, we need a line 34.5 metres long for the same effect, but needless to say this is usually out of the question. Tapered or shaded high frequency drivers can be used to restrict the effective or apparent length of the HF line as frequency increases. While this will reduce lobing and may prevent some of the problems, it is unlikely that the compression drivers used could keep up with the rest of the system."

Chris

[weltersys]

Originally Posted by djn

Hi all, I have subs, mid horns, and tweets so now I am looking at bass bins. Some time ago I whipped out a pair of line arrays just for fun using 8 4" driver each side and I was floored at how good the midbass sounded.

Is this something that all Line Arrays do well or did it just work out with what I built?

I am thinking that for bass bins I might think about 4 8" drivers per side. I don't know much about LAs, so would this make a good midbass box?

PS, I know this is a subwoofer forum, but I figured it is close so I could ask here.

A line array of around 3 feet tall (8 x 4" + some spacing) will work like a line array should more above about 375 Hz (one wavelength), and less like a line below. For much of the vocal range, that effect is quite effective in narrowing the vertical dispersion.

Four 8" is about the same height, you won't see much benefit in the "bass" range. A vertical arrangement of the four 8" will provide more even horizontal dispersion than a side by side arrangement, so if your mid bass extends above 500 Hz or so, go vertical.

[djn]

Originally Posted by hum4god

what frequency range do you want to cover ?
why not use a midbass horn like the edgar horn from 80-500hz ?
it would probably match your edgarhorn mid best .

I am going for 50hz to 500hz. I've had two pair of edgarhorn midbass horns, but in this new house, they are too deep. I am going for shallow.

Originally Posted by chris661

To get a true line array, the array of drivers must be several times the longest wavelength you want to reproduce.

A vertical line of drivers will work, but the output won't be cylindrical like a true line array.

Quote from Rod Elliott...
"The biggest single problem is that the effective line length varies with frequency. At 10kHz, even a couple of cabinets will easily exceed a line length of 10 wavelengths (at which point the line can conceivably be considered "infinite"). At 1kHz, wavelength is 345mm, so the line must be at least 3.45 metres high to be considered close to an infinite line. At 100Hz, we need a line 34.5 metres long for the same effect, but needless to say this is usually out of the question. Tapered or shaded high frequency drivers can be used to restrict the effective or apparent length of the HF line as frequency increases. While this will reduce lobing and may prevent some of the problems, it is unlikely that the compression drivers used could keep up with the rest of the system."

Chris

for this read, it looks like the size I am looking for would not work for the freqs I need......50 to 500hz.

Originally Posted by weltersys

A line array of around 3 feet tall (8 x 4" + some spacing) will work like a line array should more above about 375 Hz (one wavelength), and less like a line below. For much of the vocal range, that effect is quite effective in narrowing the vertical dispersion.

Four 8" is about the same height, you won't see much benefit in the "bass" range. A vertical arrangement of the four 8" will provide more even horizontal dispersion than a side by side arrangement, so if your mid bass extends above 500 Hz or so, go vertical.

The bass range is where I am looking so maybe a Lambda in a box might work better.

[bjorno]

Originally Posted by djn

I am going for 50hz to 500hz...for this read, it looks like the size I am looking for would not work for the freqs I need......50 to 500hz...

Who needs an infinite line array? If your floor to ceiling height is about 8 foot.:

You only need ~10 drivers to cover 70% of the floor to ceiling distance(=H) to make a good near-field line array with 6.5" drivers that effectively is magnified 3 times the mentioned distance due to the mirroring effect at floor and the ceiling.
+ by placing subs DBA-wise (double bass array) way; a minimum of 4, to cover the the frequencies(f in kHz) below 1/(3xH)...resulting in a virtual plane array wall of sub and mid bass frequencies.

b

[weltersys]

Originally Posted by djn

I am going for 50hz to 500hz. I've had two pair of edgarhorn midbass horns, but in this new house, they are too deep. I am going for shallow.

for this read, it looks like the size I am looking for would not work for the freqs I need......50 to 500hz.

The bass range is where I am looking so maybe a Lambda in a box might work better.

For the 50-500 Hz range, I'd be inclined to just use a single 15" rather than 4 8".

[DrDyna]

I use a pair of these in my mains:

https://www.madisound.com/store/prod...oducts_id=1511

I've often thought about building a box with 8 of them (and a tweet) on each side. I wonder how it would sound.

This thread has got me thinking about my saw again.

[djn]

Originally Posted by bjorno

Who needs an infinite line array? If your floor to ceiling height is about 8 foot.:

You only need ~10 drivers to cover 70% of the floor to ceiling distance(=H) to make a good near-field line array with 6.5" drivers that effectively is magnified 3 times the mentioned distance due to the mirroring effect at floor and the ceiling.
+ by placing subs DBA-wise (double bass array) way; a minimum of 4, to cover the the frequencies(f in kHz) below 1/(3xH)...resulting in a virtual plane array wall of sub and mid bass frequencies.

b

The issue I have is what ever I use for the bass bin can only be about 36" tall so my horns and tweets can fit on top and be close to ear level.

Originally Posted by weltersys

For the 50-500 Hz range, I'd be inclined to just use a single 15" rather than 4 8".

I agree welt. I think the better way to go is one Lambda TD15 in the right sized box.