Dipole specific woofer by Exodus

[riff.ca]

Seems many here are looking for dipole woofers. I just across this and have not seen it mentioned here yet.

http://www.audiocircle.com/circles/i...?topic=47277.0

[penderaudio]

Haven't seen those yet. They look like a smaller version of my Exodus 15's

[davidallancole]

Am I missing something when he is talking about the low sensitivity?

If you have a baffle cutoff of 100Hz (32.5 inch baffle from the graph on the Single Driver Website), does the system not drop off at 6 db/octave down to Fs and then 12 db/octave below Fs? That would mean with a SPL rating of 81.7dB, it would be at 69.7dB at Fs. That 12dB is a lot of power to put into it to raise it back up to flat with the rest of the system and then still have to put a lot of power into it to get it to play loud. It looks like it may be an all right speaker but I think there are others in the same price range that may do better with less power.

[TerryO]

Originally posted by davidallancole
Am I missing something when he is talking about the low sensitivity?

If you have a baffle cutoff of 100Hz (32.5 inch baffle from the graph on the Single Driver Website), does the system not drop off at 6 db/octave down to Fs and then 12 db/octave below Fs? That would mean with a SPL rating of 81.7dB, it would be at 69.7dB at Fs. That 12dB is a lot of power to put into it to raise it back up to flat with the rest of the system and then still have to put a lot of power into it to get it to play loud. It looks like it may be an all right speaker but I think there are others in the same price range that may do better with less power.

One thing that you didn't mention and is often overlooked is the role of room or cabin gain. Also, placing the driver low on the cabinet near the floor gives a mirror effect that raises the perceived level by nearly two. Placed in a corner raises it even more.

I'm not sure which graph you're speaking of, but I've seen some that are way, way off, as they take an overly simplistic approach that leave so many factors out, that they're basically useless at best and often are totally misleading. I have to say that I think that your example is too dependant on a graph and doesn't reflect the reality of dipole implementation.

High sensitivity drivers usually have a higher FS, not as much x-max and none of them, AFAIK, have an XBL2 motor. It's all about compromises, but you need to evaluate which ones you're willing to live with.

Best Regards,
TerryO

[Kevin Haskins]

The driver is designed to be used two or four in a baffle. We are doing a W baffle and the effective baffle width is much wider than on a flat baffle.

Keep an eye on my forum. I'll explain all the design details and show how they are to be used along with measurements and an explanation of the entire system. Just give me a couple weeks.

[davidallancole]

This is the graph I was referring to:

http://melhuish.org/audio/baffle.html

Thanks for the clarification guys. I will watch this one and see what happens.

[planet10]

Originally posted by davidallancole
This is the graph I was referring to:

http://melhuish.org/audio/baffle.html

At one point (either here or on the FRF, this and other charts were discussed and IIRC this one wasn't particularily accurate and certainly doesn't take the driver Q into consideration.

A better bet is to download Thorsten's baffle spreadsheet.

dave

[davidallancole]

Thanks Dave. I will look that one up.

[Kevin Haskins]

Yes...what Dave said. I don't know what other tools people are using but that graph is of little use.

Linkwitz has the best technical descriptions that I'm aware of.

If you don't want to scratch all the hair off your head, just wait and give me a little time and I'll have some more details on how to use them.

[davidallancole]

Sounds good. I downloaded Thorstens spreadsheet and it looks good.

I have a hard time reading Linkwitz's website. I need things paired down to there most simplest state to understand them until I can continue on to learn the more detail, intrecit parts (if I ever learn them).