Tiny full range drivers..like 1-2" tiny.

[Coolhandjjl]

I'm pretty sure they use some DSP-implemented steering algorithm to beam the side surround channels off at an angle so that you get the wall bounce to mimic a sound source in that location. Like to hit a side wall, you'd send that signal to widely-spaced drivers (to get a narrow pattern), and then delay the drivers on the same side as your target wall by an amount that would pull the in-phase axis over to the desired angle..

Did someone say.........Bose?

 

[trevcda]

I'm pretty sure they use some DSP-implemented steering algorithm to beam the side surround channels off at an angle so that you get the wall bounce to mimic a sound source in that location. Like to hit a side wall, you'd send that signal to widely-spaced drivers (to get a narrow pattern), and then delay the drivers on the same side as your target wall by an amount that would pull the in-phase axis over to the desired angle.

Probably doesn't work as well as the real thing, but takes up a lot less space.

It worked surprisingly very well, although as you mentioned, not nearly a well as the real thing. You have to give up a fair amount of lower frequency response to get the beam effect, but one of its features, called target mode, allowed you to to focus it to a specific spot. I use one in my bedroom to keep from bothering my girlfriend when I get home late and want to watch a little TV. When I had my audio store I sold and installed quite a few. Unfortunately I think the proliferation of plain old ordinary sound bars with three standard speakers in a similar format and a failure to differentiate the technology and its advantages, as well as most dealers poorly displaying it, relegated it relative obscurity.

 

[DukeLeJeune]

It worked surprisingly very well, although as you mentioned, not nearly a well as the real thing. You have to give up a fair amount of lower frequency response to get the beam effect, but one of its features, called target mode, allowed you to to focus it to a specific spot. I use one in my bedroom to keep from bothering my girlfriend when I get home late and want to watch a little TV.

That's a pretty impressive capability, clearly proof that the technology works. Who makes it?

When I had my audio store I sold and installed quite a few. Unfortunately I think the proliferation of plain old ordinary sound bars with three standard speakers in a similar format and a failure to differentiate the technology and its advantages, as well as most dealers poorly displaying it, relegated it relative obscurity.

You had an audio store? Very nice. I had one also... fleetingly, shall we say. Home audio stores seem to be getting fewer and father between.

 

[BurningSkies]

Like one of these?

Or this one?

[Invalid or Expired Link Removed]

I thought the Phil Jones speakers were ceramic coned?

 

[B-string]

I thought the Phil Jones speakers were ceramic coned?

Honestly have no idea? Hope I'm not shot for this, they remind me of a cartoon cab or the worst of Bose. Not a fan, just trying to post something useful for the OP.

 

[BurningSkies]

Honestly have no idea? Hope I'm not shot for this, they remind me of a cartoon cab or the worst of Bose. Not a fan, just trying to post something useful for the OP.

I've played one and I've seen one used on a fairly regular basis..they're cool...but heavy and bulky. I applaud the different approach to skinning the cat, but won't carry one. They do what he intended and do present some very real deep lows.

 

[B-string]

Nice to know they perform! Never been closer than a web page or TV audio (didn't see a mike on the cab).

 

[Munjibunga]

Important to note, speaker "sizes" are the basket diameter not the cone area. That speaker photo has more frame and outer suspension than actual useable cone area to calculate.

Also, since the cones are not flat, just calculating the area of the corresponding circle gives an area that is smaller than the actual surface area of the paper, since the paper is a frustum of a cone.

 

[Munjibunga]

Really, I don't see why you'd even mess with this. If there were any real advantage to it, you'd see products like this commercially. Phil Jones does it with 5-inch speakers and they sound pretty good, but I've never seen a PJB rig on a stage. You've got the Bose 2-inch line arrays, but they use subs for the bottom end. You need big displacement for big notes. That's not happening with teenie-weenie speakers. I'm not feelin' it.

OK, now take me out back and shoot me.

 

[Passinwind]

Also, since the cones are not flat, just calculating the area of the corresponding circle gives an area that is smaller than the actual surface area of the paper, since the paper is a truncated frustum of a cone.

Yep, and to further complicate things, speakers move through a few different modes that each utilize different amounts of surface area and cone excursion.

 

[David Jayne]

I thought the Phil Jones speakers were ceramic coned?

No just silver colored paper.

 

[flameworker]

I w, ish I had $$$ to explore thus, I ended up finding 4 8 ohm bose 4" speaker s from the 901's or something. For a bedroom amp to play with.

I found a brand new jbl pro 2225 15 on Craigslist for 50 bucks in a home made cab, good speaker, comes with free black plywood!

Great info people.

 

[flameworker]

I just took a part some junk powered subs (not pictured) for computers and home, they have tiny small drivers.

And those strange $5000 5" drivers with giant folded horns behind them are odd too.
no one uses them as rigs, maybe the response isn't there, but they are low, 18hz low..brown sound low.

I need more math. the more I learn the less I know.

 

[Inertialsky]

tiny drivers sound tiny...

putting them in a giant enclosure defeats the purpose.

 

[dincz]

tiny drivers sound tiny...

Headphones.

 

[trevcda]

That's a pretty impressive capability, clearly proof that the technology works. Who makes it?

That and the one I've got is a Yamaha YSP-4000. Pioneer also made a version with 254 tiny drivers with a hefty price tag:

Invalid Link Removed

You had an audio store? Very nice. I had one also... fleetingly, shall we say. Home audio stores seem to be getting fewer and father between.

Yeah, I had a good ten years of great customers before big box stores moved into the area and really lowered expectation for all things audio. Add to that highly compressed digital audio sources and further dumbing down via the internet. I started out as a boutique store with custom installation and design and and outlasted the Circuit City's and other companies that went belly up but got out before I had to lower my own standards to compete.

 

[Feral Feline]

Find a Cube that's shorted out its amp and steal the speakers...

Or find out where the speakers are made and get a few out the back door.

 

[fdeck]

Also, since the cones are not flat, just calculating the area of the corresponding circle gives an area that is smaller than the actual surface area of the paper, since the paper is a frustum of a cone.

What's important is not the surface area of the paper, but the volume displacement of the cone and surround per unit linear displacement, which happens to be in units of area. The easiest thing to do is just look up the Sd parameter for the driver, which is an effective area derived from electro-acoustic measurements.

If the driver maker doesn't provide those parameters on their spec sheet, move on to a different manufacturer.

In the process of trying to understand how speakers work, I've formed a few rules of thumb that might be helpful for sorting things out:

1. For any given cone diameter, you can get the same on-axis low frequency response curve (i.e., below 250 Hz) with a different diameter by playing with the other design parameters such as magnetic field.

2. Two systems with roughly equal total cone area (using the Sd parameter) can have roughly equal sensitivity, i.e., you can make a bunch of 1" cones behave like a 15"er in theory, if you can control all of the design parameters.

3. An array of small cones will have an off-axis response similar to a large single cone of the same overall width. The added space needed to accommodate the flanges of the smaller drivers will tend to make their off axis performance worse.

4. The ultimate SPL achievable by a speaker depends on its swept volume, i.e.., the product of Xmax and Sd. There have been great strides in making large diameter musical instrument and pro sound woofers with generous Xmax. Not so much for smaller home audio drivers. For this reason, I think that an array of very small drivers is almost guaranteed to produce less SPL than a single big driver of high quality.

After investigating a lot of different possibilities for my own designs, I've come to the conclusion that the highest performance is likely to favor a smaller number of larger cones. If you can get the SPL that you need with a single cone, that's likely to be your best option in terms of technical performance and economy.

 

[Steve Dallman]

I had a pair of Bose 802's in the 80's. Even not using the EQ, they were terrible for bass. Each cabinet was supposed to be 160 watts RMS for 320 for the pair. I had single 12's that would play cleaner without distortion.

The EQ for the Bose, which I still have, produces a very gentle "smile, with a shallow rise at the low and high ends. I ran it through an RTA a few years ago to see what it did.

We used the 802's in a Christian band that played coffeehouses. I also bi-amped the PA with 15's crossed around 250Hz. They were rather short throw but worked OK for us.

 

[Munjibunga]

What's important is not the surface area of the paper, but the volume displacement of the cone and surround per unit linear displacement, which happens to be in units of area. The easiest thing to do is just look up the Sd parameter for the driver, which is an effective area derived from electro-acoustic measurements.

If the driver maker doesn't provide those parameters on their spec sheet, move on to a different manufacturer.

In the process of trying to understand how speakers work, I've formed a few rules of thumb that might be helpful for sorting things out:

1. For any given cone diameter, you can get the same on-axis low frequency response curve (i.e., below 250 Hz) with a different diameter by playing with the other design parameters such as magnetic field.

2. Two systems with roughly equal total cone area (using the Sd parameter) can have roughly equal sensitivity, i.e., you can make a bunch of 1" cones behave like a 15"er in theory, if you can control all of the design parameters.

3. An array of small cones will have an off-axis response similar to a large single cone of the same overall width. The added space needed to accommodate the flanges of the smaller drivers will tend to make their off axis performance worse.

4. The ultimate SPL achievable by a speaker depends on its swept volume, i.e.., the product of Xmax and Sd. There have been great strides in making large diameter musical instrument and pro sound woofers with generous Xmax. Not so much for smaller home audio drivers. For this reason, I think that an array of very small drivers is almost guaranteed to produce less SPL than a single big driver of high quality.

After investigating a lot of different possibilities for my own designs, I've come to the conclusion that the highest performance is likely to favor a smaller number of larger cones. If you can get the SPL that you need with a single cone, that's likely to be your best option in terms of technical performance and economy.

... and there you are.