[jparkhur]

Wired and playing the last two days.   Just waiting for the breakin to finish



[/img]

[TrungT]

Look great.   

[Guy 13]

Hi jparkhur and all Audio Circle members.

Anxious to read your comments...

Very nice looking speakers.

Guy 13

[jparkhur]

Morning,  We still have to wait on the major puzzle piece as HAL has stated.. The xo is the most important part here...flattening the top end and putting in "Best".....


Jon P

[HAL]

Looking good Jon!

Will get my drivers hooked up and burning in on Friday. 

The wait for the XO is ongoing.  It is in work at this time.  Waiting on an update.

[SoCalWJS]

This looks interesting. I've heard a few single/"full range" driver speakers in my time and they do some things quite well. The trade offs have always always prevented them from serious consideration.

Reading this thread, along with some of the others currently active, has made me ask a few questions that I'm not quite sure how to ask. These questions concern the general design philosophy of speakers, single driver speakers, and the strengths and disadvantages of these various approaches. Some of them may sound critical, but I assure you they are not - I am merely seeking clarification and a better understanding.

Is it OK to ask here, or should I start a new thread? If so, should I go to a different area? (Enclosures and The Lab come to mind)?

[HAL]

If Danny is good with it, I would say post the questions here.  Should be an interesting discussion.

[Danny Richie]

This looks interesting. I've heard a few single/"full range" driver speakers in my time and they do some things quite well. The trade offs have always always prevented them from serious consideration.

Man, I feel the same way. There were just too many compromises or short comings. But I think this approach (or this solution) will remedy the short comings and even excel in those areas where the wide band drivers fall short. 

Reading this thread, along with some of the others currently active, has made me ask a few questions that I'm not quite sure how to ask. These questions concern the general design philosophy of speakers, single driver speakers, and the strengths and disadvantages of these various approaches. Some of them may sound critical, but I assure you they are not - I am merely seeking clarification and a better understanding.

Is it OK to ask here, or should I start a new thread? If so, should I go to a different area? (Enclosures and The Lab come to mind)?

Go ahead and fire away.

[SoCalWJS]

OK, here goes:

First, (and this is the one I'm most hesitant to ask as it may sound negative) - What makes this a ""Full Range Driver"?. It seems closer to a 2 way design with a driver that covers a wider range for the most critical region (say somewhere in the 150/200 Hz range on up) and very good bass drivers, with a very sophisticated crossover/digital system handling the separation between the drivers. 

Another of the issues being raised pertains to cabinet vibrations when placing a speaker on top of a subwoofer causing unwanted vibrations which in turn introduces problems to the soundstage.
So, question number 2: Why is this worse then tying them together in the same frame? Aren't vibrations vibrations?

As far as a single driver full range speaker goes: I can remember going into the Emerald Physics room at one of the shows (think it was T.H.E Show Newport) and they were playing a simple piece - Iz singing Over the rainbow. Just his clear voice and a Ukelele. I was astounded by the quality and how natural it sounded (conversely: came home and threw it on my setup and realized how far I had to go - mind you, it's better since then  ).
But then they threw on a different piece with more range and dynamics........ left the room very quickly thereafter.

What is the frequency range that should be considered anyway" I know that 20-20k is usually the standard that is used.

I know for a fact that I can no longer "Hear" above 15k, and when my tinnitus/ringing in my ears is acting up (somewhere around 10-13k), I doubt I can hear anything above that.

Yet I KNOW I can sense (feel) anything above 0 Hz - from earthquakes to subsonic things (rocket lifting off), and that if a speaker doesn't go above what I can actually hear, things sound wrong. The decay of cymbals being the one I notice most easily.
So, next question: What is the upper limit on this design? (I figure the "subwoofer section of this speaker will be very good  )

I've got more questions, but I think I can tailor them better after hearing back on these. 

[DaveC113]

This looks interesting. I've heard a few single/"full range" driver speakers in my time and they do some things quite well. The trade offs have always always prevented them from serious consideration.

Same goes for 95% of multi-way speakers. 

[Danny Richie]

I'll try to hit this with one thought at a time.

First, (and this is the one I'm most hesitant to ask as it may sound negative) - What makes this a ""Full Range Driver"?. It seems closer to a 2 way design with a driver that covers a wider range for the most critical region (say somewhere in the 150/200 Hz range on up) and very good bass drivers, with a very sophisticated crossover/digital system handling the separation between the drivers. 

What we are doing really is making a two way design out of it. But we are still using this driver as a wide band driver just like everyone else. We are just supplementing it in an area below what it is capable of playing anyway.

The real key though is what the digital correct will do for the response. Just have a look at the factory specs on the driver that we choose to test this with:  http://www.parts-express.com/pedocs/brochures/295-346-dayton-audio-ps220-8-brochure-9530.pdf

It's response has a 14db swing from 400Hz to 4kHz. And when mounted in a narrow baffle the baffle step loss will further increase that as output levels below 6 or 700 hundred Hz really drops off.

Now what if the entire range was +/-.5db or less?

It could go from being a speaker that burns a hole in your head to a very accurate speaker.

[Danny Richie]

Another of the issues being raised pertains to cabinet vibrations when placing a speaker on top of a subwoofer causing unwanted vibrations which in turn introduces problems to the soundstage.
So, question number 2: Why is this worse then tying them together in the same frame? Aren't vibrations vibrations?

Imagine mounting a speaker over a large drum. Now imagine the difference if it were mounted to the frame of the drum verses mounted on the playing surface of a drum.

It is not hard to envision the differences between this:



And this:



Now see the before and after. Before:



And after:



Comments from the owner:

Well I removed the AV-2's from the subs and placed them back on the stands I made when I built the speakers. I listened to the same pieces that I had listened to before and I could not believe the difference. Before I used the 1/4" rods the anchor the AV-2's to subs as I tried Spikes but the AV-2's would rattle on the spikes during some low passages so I firmly anchored them with the 1/4" bolts with brass tubing to make it look finished.

Danny! you were right and I just cannot believe what that little difference makes.

Panel resonances are not your friend. They exists in all speaker to some degree. Minimizing them in any way possible is a huge plus. 

[Danny Richie]

Lumping these thoughts together...

As far as a single driver full range speaker goes: I can remember going into the Emerald Physics room at one of the shows (think it was T.H.E Show Newport) and they were playing a simple piece - Iz singing Over the rainbow. Just his clear voice and a Ukelele. I was astounded by the quality and how natural it sounded (conversely: came home and threw it on my setup and realized how far I had to go - mind you, it's better since then  ).
But then they threw on a different piece with more range and dynamics........ left the room very quickly thereafter.

What is the frequency range that should be considered anyway" I know that 20-20k is usually the standard that is used.

I know for a fact that I can no longer "Hear" above 15k, and when my tinnitus/ringing in my ears is acting up (somewhere around 10-13k), I doubt I can hear anything above that.

Yet I KNOW I can sense (feel) anything above 0 Hz - from earthquakes to subsonic things (rocket lifting off), and that if a speaker doesn't go above what I can actually hear, things sound wrong. The decay of cymbals being the one I notice most easily.
So, next question: What is the upper limit on this design? (I figure the "subwoofer section of this speaker will be very good  )

I've got more questions, but I think I can tailor them better after hearing back on these.

 

Some full range drivers do some ranges really well. And many people love them just for those vocal ranges, and that is all they want to listen to. They don't care that the top end is really hot, or that they have no bass.

Some people can't get past those things and their favorite music may cause the shortcomings to just be too glaring.

If all of this works out like I think it will then these are going to be real hard to knock. There will literally be no shortcomings. Even if the customer picks a favorite full range driver that rolls off some above 15kHz or so. That too can be gained back to some degree as those ranges will simply see more output to increase the output where it was naturally rolling off. So if a driver has some reasonable output to 20kHz then it could actually be corrected to be flat to 20kHz. And the peaks that a driver may have up top can be attenuated to a much lower level. So those problems can go away as well.

[DaveC113]

If all of this works out like I think it will then these are going to be real hard to knock. There will literally be no shortcomings.

My biggest issue with a single driver (assuming it is decent to begin with) is related to SPL and transient impact. The maximum SPLs are rather limited and there isn't enough impact in the mid bass. I don't see any design that truly uses one single driver overcoming these limitations, even with subwoofers. There just isn't enough surface area....

[Danny Richie]

My biggest issue with a single driver (assuming it is decent to begin with) is related to SPL and transient impact. The maximum SPLs are rather limited and there isn't enough impact in the mid bass. I don't see any design that truly uses one single driver overcoming these limitations, even with subwoofers. There just isn't enough surface area....

That's true, but in this case the mid-bass is being covered by three 8" woofers with servo control.

[DaveC113]

That's true, but in this case the mid-bass is being covered by three 8" woofers with servo control.

Whats the x-over freq looking like? Didn't look like those drivers would extend up into the mid-bass but if so maybe that will work out... of course then you have more integration issues like with a conventional speaker as well vs. using subwoofers at ~60 Hz and lower which aren't too hard to integrate.

[SoCalWJS]

Imagine mounting a speaker over a large drum. Now imagine the difference if it were mounted to the frame of the drum verses mounted on the playing surface of a drum.

It is not hard to envision the differences between this:



And this:



Now see the before and after. Before:



And after:



Comments from the owner:

Panel resonances are not your friend. They exists in all speaker to some degree. Minimizing them in any way possible is a huge plus.

Maybe I need to rephrase and clarify the purpose of my question.

I can easily see by example of setting a speaker on the surface of a drum is a bad thing. I would never consider doing so. If you were to place a speaker on top of a truly inert subwoofer cabinet (I'm thinking of something similar to your sand-filled cabinet plans that I've seen posted), it seems that there would be very little, if any, vibrations present.

However, if I take a piece of wood or MDF and support it on either side with another piece of wood or MDF (the support columns in this case), and then mount 4 drivers (3 Subwoofers and the full range driver) in that piece of wood or MDF, it seems that there is a greater potential for vibrations unless additional bracing is used.

(not sure if I'm painting a clear, or for that matter accurate, picture  )

I guess another way of putting it is that the piture I see of the test enclosure would be somewhat inclined to vibrate w/o some additional bracing (which I readily admit could be a completely wrong conclusion without knowing more info)

[DaveC113]

I agree the pic at the bottom is far more ideal but there's a lot of people out there that want a full range loudspeaker, think bigger is better, and don't want to place subwoofers. It's not like subs are a new idea, but I think many people are only starting to see that bass coming from symmetrically set-up speakers in a rectangular room just doesn't work out so well. Certainly better with the dipole design of many GR products, but I think many people are going to start preferring smaller main speakers with multiple subs, it is technically a better solution and doesn't require huge and expensive main speakers.

[Danny Richie]

I guess another way of putting it is that the piture I see of the test enclosure would be somewhat inclined to vibrate w/o some additional bracing (which I readily admit could be a completely wrong conclusion without knowing more info)

This one is 1.5" thick with a brace down each side. And a large section of the baffle has four large holes cut through it and drivers mounted in it.



So what you really end up with is a frame work as much as a baffle. There really isn't enough baffle left for there to have any resonance issues. If it were a solid baffle with no holes then it would be pretty easy to start a resonance at some frequency range relative to its size.

So the important issue then really becomes stability and anchoring the speaker well with floor spikes so that the speaker isn't allowed to rock as it would if just placed on a carpeted floor. Of coarse this is a common issue with any speaker and not just this one.

I think many people are going to start preferring smaller main speakers with multiple subs, it is technically a better solution and doesn't require huge and expensive main speakers.

This is very true.

[persisting1]

My biggest issue with a single driver (assuming it is decent to begin with) is related to SPL and transient impact. The maximum SPLs are rather limited and there isn't enough impact in the mid bass. I don't see any design that truly uses one single driver overcoming these limitations, even with subwoofers. There just isn't enough surface area....

This is also a concern for me. Placed in a large room and playing loud, a full range driver just doesn't cut it. The x mas looks pretty decent on the full range. How will these play at high SPLs?