Line array speaker, floor to ceiling

[DanielT]

Hello,

I'm thinking of building a pair of line speakers. From floor to ceiling. Something like what is shown in the picture.

The advantage, as far as I understand, acoustically, this construction facilitates integration with the listening room, right? In my case, an ordinary furnished living room.
Good sensitivity, low distortion (if suitable speaker element is selected).

But my question, pondering is. Do not such speakers need a relatively large listening room to produce the best of its potential? Does not the listening distance need to be relatively long?

Anyone have ideas and experiences about it? Grateful for input.

 

[ppataki]

https://www.audiosciencereview.com/...-corner-line-array-project.25983/#post-887939

I have already started such a project, it will be tracked on the above link

 

[ppataki]

Also read this, it has the link to Murphy's site where the original idea is coming from

https://www.audiosciencereview.com/forum/index.php?threads/murphy-corner-line-array.25090/

 

[GimeDsp]

Hi Daniel,
the are many benefits to line arrays

1. When used close to a performer/speaker they can be both monitor and PA like the Bose units and others. this is because they don't sum to full power until a ways away.

2. When used as PA in speaker-on-stick set up they can make full use of power by placing it on the crowd.

3. When used in large hanging arrays they can provide amazing adjustability in in coverage pattern.

For HiFi, well, do you really want voices to emanate from a source that's 6 feet high when you are only 10-15 feet away?
It's VERY unnatural. but to each their own

 

[DanielT]

Aha, exciting! Thanks for the link. I will read it and I will probably have questions.

By the way, good luck with your project.

https://www.audiosciencereview.com/...-corner-line-array-project.25983/#post-887939

I have already started such a project, it will be tracked on the above link

Aha, exciting! Thanks for the link. I will read it and I will probably have questions.

By the way, good luck with your project.

 

[DanielT]

Hi Daniel,
the are many benefits to line arrays

1. When used close to a performer/speaker they can be both monitor and PA like the Bose units and others. this is because they don't sum to full power until a ways away.

2. When used as PA in speaker-on-stick set up they can make full use of power by placing it on the crowd.

3. When used in large hanging arrays they can provide amazing adjustability in in coverage pattern.

For HiFi, well, do you really want voices to emanate from a source that's 6 feet high when you are only 10-15 feet away?
It's VERY unnatural. but to each their own

Exactly my thoughts. Or my hesitation regarding building line speakers. They seem to have clear advantages, under the right conditions, but I am quite doubtful about if the right conditions are a normal-sized living room, for listening to hifi.

It's not set in stone that I will build line speakers. I'm mostly looking for speakers that sound big, that really fill the room with sound. Maybe a little fuzzy described by me but that kind of sound I'm interested in.

 

[ppataki]

My understanding (maybe wrong) is that if the line array is one-way (using small enough sized, same speakers, no crossover), it will act like a point-source device

 

[DanielT]

My understanding (maybe wrong) is that if the line array is one-way (using small enough sized, same speakers, no crossover), it will act like a point-source device

If that is the case, then it will be interesting, of course.

 

[ppataki]

My project shall be finished by end of October (fingers crossed), I will publish all my experience
We shall see (hear)

 

[DanielT]

The sensitivity with line speakers seems phenomenal. Read another thread where a person calculated with 16 drivers in each speaker and came to the conclusion that the increase in sensitivity will then be 20 * log10 (4) = 12 dB. With a starting point of 85 dB (estimation single driverer ) 2.83 V, we thus reach quite high 97 dB at 2.83 V.

It should mean, I think, that you can do with an amplifier that can have so much effect. For example, the Aiyima a07 TPA 3255 that is so well written about.

Or some other little amplifier. It would have been fun to test line speakers with the classic NAD 3020.

 

[ppataki]

Mine will be 103.7dB @2.8V using 24 speakers per channel
Dayton Audio ND91-8 drivers
You can find the details in the link I shared earlier

 

[DanielT]

Mine will be 103.7dB @2.8V using 24 speakers per channel
Dayton Audio ND91-8 drivers
You can find the details in the link I shared earlier

Wow! . Your link will be read now.

Now I do not know how experienced DIY you are so you may know this. Tips, which I read from someone who built a lot of speakers, including line speakers with many small drivers:

Order one or a few extra drivers. It's not a question if but they may be needed. You pull the screwdriver into an element. Some of the items you ordered do not work properly.And so on.

Measure the ohms for each individual element and match them right in the speakers.

Then this with series of numbers and parallel and series-connected drivers to get the right Ohm. However, do not really remember how it was with it. Pretty standard, basic in itself. If I remember correctly.

 

[fluid]

I'm thinking of building a pair of line speakers. From floor to ceiling. Something like what is shown in the picture.

But my question, pondering is. Do not such speakers need a relatively large listening room to produce the best of its potential? Does not the listening distance need to be relatively long?

There does need to be some distance and for that reason line arrays are not ideal for very small rooms. I have mine just under 3m, about the same distance apart. Anywhere from 2.5m or longer is reasonable. They benefit from being close to the front wall for bass reinforcement so this can help with listening distance in room.

The speakers you show are from wesayso and his listening distance is similar to mine except his listening position is close to the rear wall due to the room layout. Although his diyaudio thread has become long there is a wealth of information in there for prospective line array builders.

For HiFi, well, do you really want voices to emanate from a source that's 6 feet high when you are only 10-15 feet away?
It's VERY unnatural. but to each their own

With a floor to ceiling array in room voices sound like they come from the centre of the speaker in height and I don't notice anything unnatural about the presentation. There can be some different height cues due to the source being long but I don't find these apply to voices.

My understanding (maybe wrong) is that if the line array is one-way (using small enough sized, same speakers, no crossover), it will act like a point-source device

With enough small enough drivers and a reflective floor and ceiling it approaches an infinite line source not a point source.

The sensitivity with line speakers seems phenomenal. Read another thread where a person calculated with 16 drivers in each speaker and came to the conclusion that the increase in sensitivity will then be 20 * log10 (4) = 12 dB. With a starting point of 85 dB (estimation single driverer ) 2.83 V, we thus reach quite high 97 dB at 2.83 V.

It should mean, I think, that you can do with an amplifier that can have so much effect. For example, the Aiyima a07 TPA 3255 that is so well written about.

Or some other little amplifier. It would have been fun to test line speakers with the classic NAD 3020.

This is not correct. The gain of multiple sources does not apply across all frequencies. If the sources are within 1/4 wavelength of each other then they will add constructively. So from low to low mid this is the case and there is a large gain there but as frequency rises the distances between drivers becomes too great, cancellation occurs and by 10K you end up back at the sensitivity of a single driver.

Below the natural rolloff of the driver equalization is needed to raise the bass level and smooth out the rest of the response. This eats quite a lot of power and an array like this needs at least 100W or preferably more. It is not a speaker for flea powered amps.

 

[DanielT]

Aha, ok!

I'll see how it goes. My listening room, distance to the speakers may be a little too short. It's probably on the border.

Hmm maybe a supertweeter, or a number of tweeters in line? Crossover around 10,000 Hz or a bit below?
But then it probably starts to be a lot of calculation, measuring and various tricks to make it sound really good. Does not, so far, really possess the knowledge, experience and competence to fix such line speakers. .

Edit
A construction similar to the one in the picture? But hmm why would it help if a full-range driver do not fix frequencies over 10,000 Hz in a sensible way?

No, I'm doing this. I will read:

Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms (Audio Engineering Society Presents)

https://www.amazon.com/Sound-Reprod...-Loudspeakers-Engineering-ebook/dp/B074CHY128

I will return to the subject after that..

 

[Jim Matthews]

As an aside to construction, note that you can use multiple baffles joined together to create the front of each cabinet. It is not necessary to make it from one continuous "strip" of plywood. Keeping the drivers properly spaced, and the assembly torsionally stable is essential.

 

[DanielT]

There does need to be some distance and for that reason line arrays are not ideal for very small rooms. I have mine just under 3m, about the same distance apart. Anywhere from 2.5m or longer is reasonable. They benefit from being close to the front wall for bass reinforcement so this can help with listening distance in room.

The speakers you show are from wesayso and his listening distance is similar to mine except his listening position is close to the rear wall due to the room layout. Although his diyaudio thread has become long there is a wealth of information in there for prospective line array builders.

With a floor to ceiling array in room voices sound like they come from the centre of the speaker in height and I don't notice anything unnatural about the presentation. There can be some different height cues due to the source being long but I don't find these apply to voices.


With enough small enough drivers and a reflective floor and ceiling it approaches an infinite line source not a point source.

This is not correct. The gain of multiple sources does not apply across all frequencies. If the sources are within 1/4 wavelength of each other then they will add constructively. So from low to low mid this is the case and there is a large gain there but as frequency rises the distances between drivers becomes too great, cancellation occurs and by 10K you end up back at the sensitivity of a single driver.

Below the natural rolloff of the driver equalization is needed to raise the bass level and smooth out the rest of the response. This eats quite a lot of power and an array like this needs at least 100W or preferably more. It is not a speaker for flea powered amps.

Got it. I think. In some way compensate for frequencies above 10,000 Hz. Either by lowering the sensitivity of the full-range drivers below 10,000 Hz or having tweeters with high sensitivity. If I got it all right. I watched this video:

 

[DanielT]

As an aside to construction, note that you can use multiple baffles joined together to create the front of each cabinet. It is not necessary to make it from one continuous "strip" of plywood. Keeping the drivers properly spaced, and the assembly torsionally stable is essential.

Good tips

 

[fluid]

Hmm maybe a supertweeter, or a number of tweeters in line? Crossover around 10,000 Hz or a bit below?
But then it probably starts to be a lot of calculation, measuring and various tricks to make it sound really good. Does not, so far, really possess the knowledge, experience and competence to fix such line speakers. .

Edit
A construction similar to the one in the picture? But hmm why would it help if a full-range driver do not fix frequencies over 10,000 Hz in a sensible way?

No, I'm doing this. I will read:

Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms (Audio Engineering Society Presents)

https://www.amazon.com/Sound-Reprod...-Loudspeakers-Engineering-ebook/dp/B074CHY128

I will return to the subject after that..

The video from Danny does touch on some of these issues. Crossing drivers horizontally puts the issues normally seen in the vertical plane into the horizontal which makes them much more noticeable. The partial solution is to drop the crossover frequency low but this is not always possible.

You might want to look at the passive frequency shading wesayso has added as this creates more of an array and less of a line source.

Never a bad idea to read Floyd Toole's book, you won't find much about this thread topic in there though