[Guy 13]

Hi all.
For all of you that know me, you know I like to experiment, test, evaluate and compare and here is a side by side comparaison I did a few days ago and I am now sharing the results with whoever is interested by such tests...
Guy 13



Equipment tested :
A pair of V-2 (Modified a la Guy 13)
A pair of GR/Rythmik 12" servo sealed subwoofer.
A pair of Audio Nirvana 8" full range standard drivers in an open baffle enclosure (Design and built by Guy 13)
A switch box (Design and built by Guy 13) to give an instant comparaison of the different speakers. To me, it's the best way to compare the sound difference between the two enclosures.
A Niteshade Audio SE 15 (10wpc)
A Rega Apollo CD player.
A zillion different type of well recorded CD music.
The GR/Rythmik subwoofer have the more natural bass.
The V-2 woofer give more presence and go or give the impression of going deeper.
The V-2 - 8" coaxial sound natural, but veilled compare to the full range Audio Nirvana 8", however, even if the highs with the full range sounds more matural, they also sound more or less agressive depending on the type of music played.
There is no winner, only two different type of music and I like both speakers, however, I could listen to the V-2 for a longer time, because they are less agressive.





With or without damping material, not much difference, but I suspect that my living room needs further acoustic treatment. I will be back with more results.
Guy 13

[jtwrace]

There is no winner,
Guy 13

 

[Guy 13]

Hi.
Do you agree or disagree with me ? ? ? ? ?
Guy 13

[jtwrace]

Hi.
Do you agree or disagree with me ? ? ? ? ?
Guy 13

The name of the thread "The winner: V-2!"   

[Guy 13]

The name of the thread "The winner: V-2!"   

Hi.
Sorry about that, despite what I wrote in my thread, the winner is really the V-2 since I could listen to them all day long...
Guy 13.

[jtwrace]

Hi.
Sorry about that, despite what I wrote in my thread, the winner is really the V-2 since I could listen to them all day long...
Guy 13.

No need to be sorry.  I just thought it was funny.   

[Guy 13]

No need to be sorry.  I just thought it was funny.   

Well... You are funny !
Keep the good (Funny) work.
Guy 13

[Danny Richie]

That Audio Nirvana driver is being held back quite a bit.

For one the baffle is so large that all the imaging will be very compromised. That is a LOT of surface reflections.

Secondly, it has an aggressive rising response that puts the top end up there about 10 or more db above the midrange. It needs an aggressive compensation circuit to balance out the response.

The Super 12 that I measured on an open baffle needed a compensation filter and two notch filters to get it to a range where it can be tolerated. The response was still a little rough though, and not in the same category as the P-Audio drivers that I was using. So don't expect the improvements to move them that far, but it is still a big improvement.

[Guy 13]

That Audio Nirvana driver is being held back quite a bit.

For one the baffle is so large that all the imaging will be very compromised. That is a LOT of surface reflections.

Secondly, it has an aggressive rising response that puts the top end up there about 10 or more db above the midrange. It needs an aggressive compensation circuit to balance out the response.

The Super 12 that I measured on an open baffle needed a compensation filter and two notch filters to get it to a range where it can be tolerated. The response was still a little rough though, and not in the same category as the P-Audio drivers that I was using. So don't expect the improvements to move them that far, but it is still a big improvement.

Hi all.
What do you do you mean by :
Audio Nirvana driver is being held back quite a bit.
Yes, a lot of surface, but no reflection, look again at the picture, because  the back is fully lined with absorbing material. It might not be NoRez, but it does absorb the sound waves... The baffle is made with 1'' thick MDF.



You say and I quote : It needs an aggressive compensation circuit to balance out the response.
Unquote.
There we go again ! More parts...
The idea for using a full range driver, it's because of it's simplicity.
The way I see it, even the most expensive full range Lowther driver need somekind of correction. I would say, without having any proof, that 99% of the Lowether owners enjoy their drivers without any passive correction circuit. Are they all missing something ?
I know : No pain - no gain.
In this case : No extra parts (Crossover) no sound improvement.
My Audio Nirvana 8" full range drivers are paid for and I will keep them and use them to compare them with different other make and models of drivers.
You don't like my ideas = You don't like me.
You don't need to like my ideas to like me.
I am who I am, like it or not !
I have my ideas and you have yours...
Lets share and exchange our different ideas, but always in a friendly way.
Have a nice day.
Guy 13.
 

[Danny Richie]

I like you very well. I didn't share my findings with you to criticize, but to help you. Don't take it personal.

Your surface reflections are not from the back side of the driver that will be an issue. It is the surface reflections on the front side. A smaller baffle will improve imaging. That's a given.

As for full range drivers and corrective circuits... Most do need something. The only exception that I know of is the FR125's from CSS. With those drivers the XBL^ motor design adds so much output gain to the lower region that it tends to mirror image the baffle step loss.

I used 8 parts in the circuit to compensate for the response problems in the Super 12 model. I also shared it with the owner of the company David Dicks. I don't think he felt it needed any of that. He liked it the way it was. I couldn't listen to it the way it was. It was burning a hole in my head with the top end that hot. We don't have to agree and I am still on great terms with David. I have helped him with various designs and he has helped me too. He was the one that insisted I try the P-Audiio driver that I used in the Super-V. He was right. It really was excellent. But I liked it much better with a more aggressive network. He liked it with the woofer playing wide open and just a cap on the tweeter. His way made an extremely rough response and hot top end. But that is the way he liked it.

One of the great things about this hobby is that you can do it your way.

It's all good.

[jtwrace]

One of the great things about this hobby is that you can do it your way.

Oh and he did it his way for sure.   

[Guy 13]

I like you very well. I didn't share my findings with you to criticize, but to help you. Don't take it personal.

Your surface reflections are not from the back side of the driver that will be an issue. It is the surface reflections on the front side. A smaller baffle will improve imaging. That's a given.

As for full range drivers and corrective circuits... Most do need something. The only exception that I know of is the FR125's from CSS. With those drivers the XBL^ motor design adds so much output gain to the lower region that it tends to mirror image the baffle step loss.

I used 8 parts in the circuit to compensate for the response problems in the Super 12 model. I also shared it with the owner of the company David Dicks. I don't think he felt it needed any of that. He liked it the way it was. I couldn't listen to it the way it was. It was burning a hole in my head with the top end that hot. We don't have to agree and I am still on great terms with David. I have helped him with various designs and he has helped me too. He was the one that insisted I try the P-Audiio driver that I used in the Super-V. He was right. It really was excellent. But I liked it much better with a more aggressive network. He liked it with the woofer playing wide open and just a cap on the tweeter. His way made an extremely rough response and hot top end. But that is the way he liked it.

One of the great things about this hobby is that you can do it your way.

It's all good.

Hi Danny.
It's good to know that you like me well.... (Ha, ha...)
If you want to help me, that's good, I will try not to take it personally !
This weekend, I will do a test with my Audio Nirvana 8" fullrange drivers, I will cut some MDF board and make the front baffle as per the dimensions of your V-2. Of course I will share the results with you and all the AC members and I will not hesitate telling you that you were right with your recommendations.
I found the information for the FR125's from CSS and I might order some drivers from them. I think I might have to go with four (04) drivers per channel to get the same cone surface as one 8" driver, what do you think ?
One thing I would like to see available from GR Research is a cross over board fully assembled, something like the picture below. I am sure you can do it, get it done by Skiing Ninja is way too expensive for me.



Yes, I can do it my way, but as I learn with my mystakes, I listen more to the experts...
Have a nice week end.
Guy 13.

[Guy 13]

Oh and he did it his way for sure.   

Hi JTW,
I am sure you also sometime do it your way, am I right ?
If every AC members would do it according to the book or to the specs, it would be boring. Yes, no or maybe ?
Guy 13

[S Clark]

Guy, one of the main reasons for not doing it "your" way is that you have purchased a kit from a professional designer with 10's of thousands of hours of experience.  Also, the V2 kit is the result of perhaps hundreds of hours of his work, using that experience, with state of the art measuring equipment.  If you take his design, change the dimensions, move the drivers, or alter the crossover without that experience or measuring ability, you end up with an amateur diy speaker that has little to do with the sound of the original design or designer. 
My advice to any amateur that wants to design their own speakers, it to start with a great kit.  Build it and treat your room.  That gives you a reference point against which you can measure your own creations.   If you are seriously going to build, then purchase a quality measuring system including a properly calibrated microphone, and a hundred of so resistors, capacitors, and inductors. 
Although designing speakers is not exactly rocket science anymore, it still is involved and more difficult than the average beginner recognizes.  For example, by changing the baffle dimensions, you change the point at which woofers begin to diffract, which in turn affects how the crossover is built to controlling the interaction with the mids.  There are good simulation programs out there to predict these effects, or you can see if for yourself with a measuring system.  With simulation or measurement, you can make your changes in ways that allow you to predict or measure the outcomes- which doesn't always lead to success, but definitely improves your chance. 
You have an excellent set of kits with the V2 and the servo sub.  My recommendation is to scrap the mis-measured cabinets, and build according to the designers plans.
Sorry Guy, I have no doubt that this is not what you want to hear, but I have absolutely no doubt that it would result in the best sound that you can get out of those kits rather than randomly trying improve on the original design.  And lose the egg crate foam.  Best of luck with your project.
Scott

[jhm731]

Guy 13-

FYI, here's a measurement I took of the Audio Nirvana 'Super 8 Alnico' on the OB shown below.





 

[Danny Richie]

This weekend, I will do a test with my Audio Nirvana 8" fullrange drivers, I will cut some MDF board and make the front baffle as per the dimensions of your V-2. Of course I will share the results with you and all the AC members and I will not hesitate telling you that you were right with your recommendations.

The small baffle will improve the imaging quite a bit but will also decrease output across the bottom end. You'll need to put about a 1.5mH inductor in line with it and by pass it with a resistor value of between 4 and 8 ohms.

I could give the same advice for jhm731. That's a pretty good response curve for that driver, but while the large baffle brought up the response below 800Hz it also really hurt the imaging.

I found the information for the FR125's from CSS and I might order some drivers from them. I think I might have to go with four (04) drivers per channel to get the same cone surface as one 8" driver, what do you think ?

They are great divers within their limitations. I have a pair on my desk as computer speakers right now.

You can't line up a bunch of full range drivers and let them play full range though. What happens then is they cancel each other out all over the place. There is a way to make it work, but only one can play full range. The rest have to be wired so that they only share the load in the lower ranges where wavelengths are longer. You are still stuck with the 83 to 84db sensitivity of a single unit though.

One thing I would like to see available from GR Research is a cross over board fully assembled, something like the picture below. I am sure you can do it, get it done by Skiing Ninja is way too expensive for me.

It would be even more expensive if I assembled them. I really can't be allocating my time right now to do assembly work.

[jhm731]

I could give the same advice for jhm731. That's a pretty good response curve for that driver, but while the large baffle brought up the response below 800Hz it also really hurt the imaging.

Danny-

Thanks, but don't need the advice. Sent the ANS8As back to David for a refund.

[Danny Richie]

Danny-

Thanks, but don't need the advice. Sent the ANS8As back to David for a refund.

So what have you settled on? Or have you settled?

[jhm731]

So what have you settled on? Or have you settled?

I'm currently using a pair of GMA EOS.

[Rclark]

Guy, one of the main reasons for not doing it "your" way is that you have purchased a kit from a professional designer with 10's of thousands of hours of experience.  Also, the V2 kit is the result of perhaps hundreds of hours of his work, using that experience, with state of the art measuring equipment.  If you take his design, change the dimensions, move the drivers, or alter the crossover without that experience or measuring ability, you end up with an amateur diy speaker that has little to do with the sound of the original design or designer. 
My advice to any amateur that wants to design their own speakers, it to start with a great kit.  Build it and treat your room.  That gives you a reference point against which you can measure your own creations.   If you are seriously going to build, then purchase a quality measuring system including a properly calibrated microphone, and a hundred of so resistors, capacitors, and inductors. 
Although designing speakers is not exactly rocket science anymore, it still is involved and more difficult than the average beginner recognizes.  For example, by changing the baffle dimensions, you change the point at which woofers begin to diffract, which in turn affects how the crossover is built to controlling the interaction with the mids.  There are good simulation programs out there to predict these effects, or you can see if for yourself with a measuring system.  With simulation or measurement, you can make your changes in ways that allow you to predict or measure the outcomes- which doesn't always lead to success, but definitely improves your chance. 
You have an excellent set of kits with the V2 and the servo sub.  My recommendation is to scrap the mis-measured cabinets, and build according to the designers plans.
Sorry Guy, I have no doubt that this is not what you want to hear, but I have absolutely no doubt that it would result in the best sound that you can get out of those kits rather than randomly trying improve on the original design.  And lose the egg crate foam.  Best of luck with your project.
Scott

yeah, what he said.