Something I'd like to try....

[Phelonious Ponk]

I think about this from time to time. You all know I'm very much into active technology. I'm also a big believer in the 5 to 6 inch midrange driver. Get much bigger than that and I think I hear them struggling to stay coherent high enough to cross over to most tweeters. Last but not least, I'm a big fan of domes, particularly soft dome, tweeters. The best of them image really well, are very precise and detailed without getting "etched." IMHO. So for me, the best small system is a pair of active monitors with whatever sub(s) are required for the room.

How about the ideal BIG system?

What if you could put two, or even 3 pairs of small active monitors (preferably grossly overpowered ones with built in DSP) on telescoping stands in a room with mobile absorbers and diffusers, along with 2 - 4 subs. Then experiment with the positioning - including depth and height - of the monitors, positioning of the subs, positioning of the room treatments. Find a set-up for precise imaging, a set-up for a huge sound stage, a set up for....I don't know, what do you want? Use your imagination. Just to be clear, I'm still talking about 2-channel.

Has anyone ever heard of such an experiment?

Tim

 

[Bill Hart]

I think about this from time to time. You all know I'm very much into active technology. I'm also a big believer in the 5 to 6 inch midrange driver. Get much bigger than that and I think I hear them struggling to stay coherent high enough to cross over to most tweeters. Last but not least, I'm a big fan of domes, particularly soft dome, tweeters. The best of them image really well, are very precise and detailed without getting "etched." IMHO. So for me, the best small system is a pair of active monitors with whatever sub(s) are required for the room.

How about the ideal BIG system?

What if you could put two, or even 3 pairs of small active monitors (preferably grossly overpowered ones with built in DSP) on telescoping stands in a room with mobile absorbers and diffusers, along with 2 - 4 subs. Then experiment with the positioning - including depth and height - of the monitors, positioning of the subs, positioning of the room treatments. Find a set-up for precise imaging, a set-up for a huge sound stage, a set up for....I don't know, what do you want? Use your imagination. Just to be clear, I'm still talking about 2-channel.

Has anyone ever heard of such an experiment?

Tim

Isn't this what Wilson did originally, in the Whamm (not using small actives, but an amalgam of different speakers, all aligned for time/coherence, etc.). And don't some of those modern line arrays or whatever you call them that use a tall stack of small drivers seek to accomplish another aspect of what you are describing?
I guess I'd worry about coherence, crossovers, etc. (but you're doing this digitally, with time correction, right?).
do you have enough equipment to try it?

 

[treitz3]

Hello, Tim. I do believe that lobing would present your most serious issue with this type of arrangement.

Tom

 

[Phelonious Ponk]

I don't have the equipment, just the dream. I wasn't imagining just setting them up as a column,though that is one option. I was envisioning trying different arrangements, with the speakers at different height, width and depth relationships to each other. Treats, tell me about lobbing

Tim

 

[JackD201]

Hello, Tim. I do believe that lobing would present your most serious issue with this type of arrangement.

Tom

It would if Tim tried to place pairs from the same channel too far apart. Stacking has been going on for a long time, the most popular being the stacking of Advents. Dynaudio Evidence speakers are essentially stacked. Concentric arrays with W-M-T-M-W arrangements (VR-11s, Raidho C-5s, PBS Montanas, MM3s) can be thought of as stacked but these usually share a tweeter. Morel has a modern implementation of stacked 2-ways with a matching stand for them.

I say go for it Tim.

 

[treitz3]

http://en.wikipedia.org/wiki/Acoustic_lobing

Basically and in layman's terms, it smears/distorts the image.

Tom

 

[Phelonious Ponk]

http://en.wikipedia.org/wiki/Acoustic_lobing

Basically and in layman's terms, it smears/distorts the image.

Tom

Hmm...if I understand that properly, then the best position Would be a stack, a vertical column of tweeters and mid-bass divers. Not sure there's much to be gained there but volume.

Tim

 

[JackD201]

Yup, about 6dB total for the same output signal if voltage is not halved at the source or preamp output. Good news is that most of this goes straight to headroom. If smearing can be avoided, what you will get is a more effortless portrayal. Expect pinpoint imaging to suffer however unless you plan to sit quite a bit farther away.

 

[LL21]

Stacking has been going on for a long time, the most popular being the stacking of Advents. Dynaudio Evidence speakers are essentially stacked. Concentric arrays with W-M-T-M-W arrangements (VR-11s, Raidho C-5s, PBS Montanas, MM3s) can be thought of as stacked but these usually share a tweeter. Morel has a modern implementation of stacked 2-ways...

Does W-M-T-M-W also describe the Arrakis...which is essentially one Altair placed on the top of the other with a shared tweeter?

 

[Vincent Kars]

Hmm...if I understand that properly, then the best position Would be a stack, a vertical column of tweeters and mid-bass divers. Not sure there's much to be gained there but volume.

Tim

Something like this?

http://www.merovinger-audio.de/wordpress/?page_id=339

 

[Phelonious Ponk]

Yup, about 6dB total for the same output signal if voltage is not halved at the source or preamp output. Good news is that most of this goes straight to headroom. If smearing can be avoided, what you will get is a more effortless portrayal. Expect pinpoint imaging to suffer however unless you plan to sit quite a bit farther away.

So I get more volume but lose imaging if I'm not further away. And I will, of course, lose much of the volume sitting further away. How about sound stage? Immersion? Or would I just be adding on the extra drivers and amps to get basically the same effect in a larger space, from a greater distance?

Tim

 

[JackD201]

Hi Lloyd,

Yup

Hi Tim,

Imagine how a two way would radiate. The pattern would take on the shape of a bubble. Stacking a pair of them would still be like a bubble but it would be a bit deformed like an hourglass almost until the wavelengths match up and it would be a bubble again albeit a larger one. Remember lobing? If not lined up properly the cancellations would cause dips in response so that is the most crucial part. Good news is since you will be going active, you will know the exact XO frequencies and can easily compute the wavelengths from there. Also, because you will be moving twice as much air per side you will definitely have your summing at more audible levels and over a greater volume of the room which is what allows a soundstage to develop in the first place. You will also likely space the stacks farther away from each other so it follows that the greater probability is that you will have a larger sound stage.

It's true that you will be giving up about the same number of dBs but only if you double the listening distance. With a squat 2 way where the distance of one edge of a woofer to another is measured in the inches, I doubt very much you will be more than 4 meters away. You'd be at 3m at most and many monitors are fairly flat up to 2m. Room treatments or DRC should be able to easily compensate for the nonlinearities from the reflections.

While you will not be doubling up on perceived loudness, you will be halving the voltage required to reach the same reference SPL. That's where the fun part begins because, as I said, this goes straight to headroom. Your circuits and drivers will be running under less thermal stress and this means lower distortion.

While you can play louder, chances are you won't go past your personal comfort zone anyway. However, this lowering of thermal distortion accompanied by more power reserves on tap at the amp rails, as well as coils running more efficiently will give you what we audiophiles like to call, a sense of ease.

All swell in theory but it will be a game of millimeters when it comes to the speaker placements. I would not attempt to do this without a measuring device or better yet a suite. Doing it by ear would take me forever.

Best,

Jack

 

[Phelonious Ponk]

Hi Lloyd,

Yup

Hi Tim,

Imagine how a two way would radiate. The pattern would take on the shape of a bubble. Stacking a pair of them would still be like a bubble but it would be a bit deformed like an hourglass almost until the wavelengths match up and it would be a bubble again albeit a larger one. Remember lobing? If not lined up properly the cancellations would cause dips in response so that is the most crucial part. Good news is since you will be going active, you will know the exact XO frequencies and can easily compute the wavelengths from there. Also, because you will be moving twice as much air per side you will definitely have your summing at more audible levels and over a greater volume of the room which is what allows a soundstage to develop in the first place. You will also likely space the stacks farther away from each other so it follows that the greater probability is that you will have a larger sound stage.

It's true that you will be giving up about the same number of dBs but only if you double the listening distance. With a squat 2 way where the distance of one edge of a woofer to another is measured in the inches, I doubt very much you will be more than 4 meters away. You'd be at 3m at most and many monitors are fairly flat up to 2m. Room treatments or DRC should be able to easily compensate for the nonlinearities from the reflections.

While you will not be doubling up on perceived loudness, you will be halving the voltage required to reach the same reference SPL. That's where the fun part begins because, as I said, this goes straight to headroom. Your circuits and drivers will be running under less thermal stress and this means lower distortion.

While you can play louder, chances are you won't go past your personal comfort zone anyway. However, this lowering of thermal distortion accompanied by more power reserves on tap at the amp rails, as well as coils running more efficiently will give you what we audiophiles like to call, a sense of ease.

All swell in theory but it will be a game of millimeters when it comes to the speaker placements. I would not attempt to do this without a measuring device or better yet a suite. Doing it by ear would take me forever.

Best,

Jack

To tell the truth, it sounds like far too much trouble. In my ignorance, I thought that maybe by placing one pair in a normal position relative to the sweet spot and a second pair higher, a bit further back and perhaps a bit farther apart, in a larger room, that I might be able to get the imaging from the normal pair while expanding the height, depth and breadth of the staging with the second pair. Perhaps I should read more and dream less. It sounds like that kind of placement would be creating problems, not solving them, and that what might work - the simple stack - won't really buy me anything but greater volume, maybe a larger listening space. Would that get me a bigger sound stage? A different one perhaps, but if you get a recording that is mixed for a big sound stage - the most important element - the staging of playback seems to be pretty relative to the size of the listening room and the distance of the listener. In other words, given the right recordings, I get a pretty massive presentation from just a meter and a half away . I hear the "sound stage" expand and contract all the time, dramatically, with a change of track. Volume? I need more volume like I need a shot to the head. Same for "ease." Until you've heard a 6" X 1" monitor, actively crossed to a 75 watt amp for each tweeter and a 250 watt amp for each woofer, or the equivalent, depending on efficiency, I suppose, I'm not sure you've really heard a 6" X 1" monitor. It is a completely different game from driving similar speakers passively, even with a very hefty amp. Gobs of clean volume without any strain. Far more than I'll ever need, even from 3 meters away.

Good conversations. Thanks for your perspectives. I think you guys saved me a weekend. Back to square one; the only thing I really need are subs. In this room? Probably just one.

Tim

 

[treitz3]

Tim, please allow me to comment a little further on what I have experienced with this kind of set up. You had made the comment about possibly getting a bigger sound stage. Well, the perceived sound stage would increase. At times, to a very pleasurable sound that seems pretty exciting when you first hear it. It's definitely different than what you are used to hearing. It will seem as if the sound stage gets bigger and the.....oh, I don't really know how to describe it.....I guess the "authority" of the system seems to be improved.

The problem arises when you set things up as you describe when lobing comes into play. I'll give you an example of what will happen in terms of the image getting distorted or smeared, if you will. Let's say that a female is singing and she is located about two feet off to the right side of the sound stage. Now, I'm taking for granted that this imagined system has a good degree of pin-pointability with the images and not something like a planar or long ribbon that will typically disperse the sound into a general image. Back to the female singer. She's over to the right, we'll say centered from front to back on the stage.

As one listens [with the setup you had described in the OP], you might notice that as she is singing that she is off to the right side, centered from front to back but when she starts to change notes? Even though she physically may not have moved her location on the sound stage, she will move on the sound stage. Sometimes more forward or backwards while at the same time, left to right. This will happen most noticeably when she is changing notes and as far as I know, there is absolutely no way to correct this. For example, certain notes that she sings will be more to the left front of the original image while other notes would end up being back and to the right of the original image. Generally, the same notes will place her back in the same location(s) but the fact that the image locational cues change when she does not move? It can get rather annoying fairly quickly and this is only one example.

That said, stacking the speakers like the way some had suggested earlier in the thread can produce some good to great results with little to negligible lobing. Jack had mentioned this...

All swell in theory but it will be a game of millimeters when it comes to the speaker placements. I would not attempt to do this without a measuring device or better yet a suite. Doing it by ear would take me forever.

I can agree. It is a fun experiment if you ever do have a weekend to play around.

Tom

 

[LL21]

Good conversations. Thanks for your perspectives. I think you guys saved me a weekend. Back to square one; the only thing I really need are subs. In this room? Probably just one.

Tim

Good luck with subs...have used one in my system since 1993...

 

[Phelonious Ponk]

Tim, please allow me to comment a little further on what I have experienced with this kind of set up. You had made the comment about possibly getting a bigger sound stage. Well, the perceived sound stage would increase. At times, to a very pleasurable sound that seems pretty exciting when you first hear it. It's definitely different than what you are used to hearing. It will seem as if the sound stage gets bigger and the.....oh, I don't really know how to describe it.....I guess the "authority" of the system seems to be improved.

The problem arises when you set things up as you describe when lobing comes into play. I'll give you an example of what will happen in terms of the image getting distorted or smeared, if you will. Let's say that a female is singing and she is located about two feet off to the right side of the sound stage. Now, I'm taking for granted that this imagined system has a good degree of pin-pointability with the images and not something like a planar or long ribbon that will typically disperse the sound into a general image. Back to the female singer. She's over to the right, we'll say centered from front to back on the stage.

As one listens [with the setup you had described in the OP], you might notice that as she is singing that she is off to the right side, centered from front to back but when she starts to change notes? Even though she physically may not have moved her location on the sound stage, she will move on the sound stage. Sometimes more forward or backwards while at the same time, left to right. This will happen most noticeably when she is changing notes and as far as I know, there is absolutely no way to correct this. For example, certain notes that she sings will be more to the left front of the original image while other notes would end up being back and to the right of the original image. Generally, the same notes will place her back in the same location(s) but the fact that the image locational cues change when she does not move? It can get rather annoying fairly quickly and this is only one example.

That said, stacking the speakers like the way some had suggested earlier in the thread can produce some good to great results with little to negligible lobing. Jack had mentioned this...



I can agree. It is a fun experiment if you ever do have a weekend to play around.

Tom

A moving image? That would annoy the bejeezus out of me.

Tim