Request for Dipole MTM with Active Crossover

[howburger]

Jon, this is a plea to you for an active dipole MTM using the Behringer DCX2496 that would provide a fairly simply constructed speaker with a downloadable crossover file directly to the DCX. I recall you saying that you were contemplating getting the DCX to mess with and to try to duplicate certain filters. Is anything like this even remotely of any interest to you in the future? I would think that a dipole, easily built by the DIY masses, with a no fuss turnkey active crossover, would be highly desirable :yesnod: . But then again, I could be wrong. After building my 4 15" driver IB, I have 4 left that I would love to build a dipole bass bin with and roll in under the suggested project and over the IB.

Harold

[Dennis H]

I'm not Jon but the DCX isn't currently available and he doesn't have one. And knowing Jon, using a DCX for anything other than a reasearch tool probably wouldn't interest him. If you already have a DCX, you might check out Monte Kay's project.

http://www.mfk-projects.com/rs_dipole.htm

[Doug Lockwood]

Harold;

If you have a DCX, there are several of us that can help.
I have thought of duplicating the Modula MTM with the DCX.
All the concepts have been discussed on the board in various threads.

While the end product would have different strengths and weaknesses than the Modula, my limited experience suggests that its a relatively low risk project that should produce a fine speaker.

Doug

[ThomasW]

Hi Harold.... :B

In the sticky of 'archived reference threads' there is some info about duplicating Jon's CE filters with the DCX.

I have 4 left that I would love to build a dipole bass bin with and roll in under the suggested project and over the IB.

I use a standard active 24dB L/R for the woofers in my Arvo prototypes. So all you'd need would be the MTM part of Jon's XO.

[howburger]

Thanx for your input guys. I'm looking for the lazy man's way through this. I would really like to stick to a MTM dipole and be able to utilize the 4 Atlas 15 drivers I've got for a bass bin. Thomas, I guess I could just use the MTM portion of the ARVO, set my processor main crossover to between 120 and 150 hz +/-, and use a crossover, such as the one you used, to cross the bass bins to the mains and to the IB at about 40 to 50 hz. I'm just a guy that's able to follow directions, I do not have any measuring equipment or design skills. Does this sound like the right path? I also may need help determining what is the final, or best, version of the ARVO.

Harold

[ThomasW]

You want to run the woofers higher than 120-150. The regular Arvo XO point is 175. Since I'm using an IB sub, Jon insisted I raise the XO point because of something about having too small (narrow) a passband wasn't a good idea for getting the best SQ. So I'm using 200 or 225, I can't remember off the top of my head.

Neither Jon nor I have a DCX2496, so we can't do a step by step for creating the MTM XO with it. Perhaps one of the DCX owners can help you there.

[Davey]

I can help you with the initial setup of the DCX for dipole system. If you get to the point of a "final" crossover however, I wouldn't use the DCX. It's compromised in this usage IMHO because of dynamic range considerations if a nominal or greater amount of dipole EQ is required. An analog active crossover is superior in all respects. It's fun to play with as a development tool though.

http://home.comcast.net/~dreite/Davey/Davey.htm

Davey.

[howburger]

Thanx Davey:

I've seen your project a number of times. I'm sure it's something that I would be happy with. I really think that assembling an active crossover circuit board would be over my head at this point. I had not heard that the DCX would limit the dynamic range. I think my best bet at this point is to wait for the ARVO thread to be cleaned up and whittled down to the best options, including the RS28 tweeter option, and take the passive route using just the MTM portion of the ARVO and using an adjustable analog active Rane or Behringer crossover to cross my soon-to-be double Atlas 15" dipole bass bins to the MTM and to my IB Sub. I appreciate the offer to help, I just don't think I'm up to the task at this point.

Thanx again,

Harold :thanku:

[Doug Lockwood]

I wouldn't use the DCX. It's compromised in this usage IMHO because of dynamic range considerations if a nominal or greater amount of dipole EQ is required. An analog active crossover is superior in all respects. It's fun to play with as a development tool though.

I agree with Davey that the DCX2496 has issues with applying more than 10-12 db of dipole Eq. I also think its a great tool to understand design choices with crossovers. And a lot of fun. :T

However, as with most things, there are design choices that can be made to reduce the dependency on Dipole EQ. A wider baffle (and to a lesser extent, a taller one as well) will result in a larger "D", which translates directly into less LF EQ, and higher output capabilities / lower distortion on the mid/base drivers. The trade-off (there are always trade-offs) is lower WAF, and compromised imaging in smaller rooms.
Another is to cross to an Sub, which you are already doing.
A third is to add a supplemental Dipole eq on the output of the DCX2496.

By the way, I consider the AVRO to be first rate. Hats off to Jon. ;x(

I also will be willing to help with DCX setup if you decide to go this way.

Doug