Danny any reason you don't offer TMM speakers?

AKLegal · « **on:** 30 Aug 2013, 06:54 pm »

in either a 2 way or a 2.5 version? Just curious.

Danny Richie · « **Reply #1 on:** 30 Aug 2013, 09:47 pm »

Quote from: AKLegal on 30 Aug 2013, 06:54 pm

in either a 2 way or a 2.5 version? Just curious.

I have tried the same design as a TMM verses a MTM. The problem with going with the TMM is that the acoustic center of the woofers is a midway point between the two woofers. This pushes the acoustic centers much further apart and would require the crossover point to be much lower.

Ideally you want the crossover point to be a longer wavelength than the wavelength of the spacing. If not then the drivers won't blend very well. You'll get the sound of two separate drivers rather than a seamless blend of the two. Take our A/V Series speakers for instance. The center to center spacing is only 4.75". That is about 2,750 Hz. The crossover point of our A/V Series designs cross between 1,900 and 2kHz. So good shape there.

If the drivers were a TMM then the acoustic center spacing would be 8". That's about 1700Hz. Too far apart and it won't sound good. It also has a big negative effect on the vertical off axis response. The added distance will cause an out of phase drop out in the vertical off axis. And this is with small 5.25" woofers and a frame that allows the woofer to overlap onto the tweeter face plate.

If only the top woofer crossed to the tweeter in a 2.5 way design then the sensitivity would drop quite a bit. Plus putting the lower woofer on its own larger inductor will cause a phase delay, and that doesn't sound as good either.

skalos · « **Reply #2 on:** 30 Aug 2013, 10:37 pm »

Thanks Danny. Your reply was clear and simple to follow.

AKLegal · « **Reply #3 on:** 31 Aug 2013, 12:16 am »

Thanks Danny

Jonathon Janusz · « **Reply #4 on:** 31 Aug 2013, 03:35 pm »

Somewhat related question that came to mind after reading this thread. I read about Duke and James' LCS array project that they will be demonstrating soon, and it got me thinking about your omni speakers, Danny. This thread and your replies put this thought in mind:

Would there be any advantage (power handling? something more?) to a TM arrangement speaker with another woofer on the top? Think like your existing omni designs with an additional woofer on the front baffle. I was thinking on the discussion of the LCS array idea, and that it is utilizing the distance from the driver-ceiling-listener as the delay vehicle in creating the ambiance sound delivery, and that made me think if this is similar to how your omni designs work. I was wondering if augmenting a traditional TM arrangement with an "ambiance" woofer like your omnis could work kind of as an "all in one box" solution to a similar design approach? I remember seeing the speakers you designed that Virtue is offering with the tweeters at a 45 degree angle to the woofers; maybe this is all treading similar ground?

Cheers!

Danny Richie · « **Reply #5 on:** 31 Aug 2013, 04:15 pm »

Yeah, something like this:

It is actually the top woofer that crosses to the tweeter. The lower woofer gives some low frequency reinforcement only. These things image like you wouldn't believe. They create a great life sized sound field.

I think a lot of people have a tough time with the looks though. They don't understand it and it is too far from the norm.

mlundy57 · « **Reply #6 on:** 31 Aug 2013, 04:53 pm »

How particular is a speaker like this on placement?

As for looks, I would think a grill could be designed that would smooth out the angles which would help the speaker blend in better.

Mike

Danny Richie · « **Reply #7 on:** 31 Aug 2013, 04:57 pm »

Quote from: mlundy57 on 31 Aug 2013, 04:53 pm

How particular is a speaker like this on placement?

As for looks, I would think a grill could be designed that would smooth out the angles which would help the speaker blend in better.

Mike

Like any omni speaker it really needs to be at least three feet from any wall.

mlundy57 · « **Reply #8 on:** 31 Aug 2013, 05:35 pm »

Other than that do they need to toe in to a particular sweet spot or do they cast a really wide listening window so you would point them straight into the room?

Mike

Danny Richie · « **Reply #9 on:** 31 Aug 2013, 05:40 pm »

Quote from: mlundy57 on 31 Aug 2013, 05:35 pm

Other than that do they need to toe in to a particular sweet spot or do they cast a really wide listening window so you would point them straight into the room?

Mike

Imaging is really good and really focused regardless of toe in.

mlundy57 · « **Reply #10 on:** 31 Aug 2013, 05:47 pm »

Is that true of any omni and/or OB design?

Mike

Danny Richie · « **Reply #11 on:** 31 Aug 2013, 05:54 pm »

Quote from: mlundy57 on 31 Aug 2013, 05:47 pm

Is that true of any omni and/or OB design?

Mike

Actually the OB designs cancel output at 90 degrees off axis. So the toe in changes the pattern. And some OB designs have really unnecessarily wide baffles and toe in has quite a bit of an effect.

mlundy57 · « **Reply #12 on:** 31 Aug 2013, 07:19 pm »

Thanks

I'm learning, or at least trying to

Mike

Danny Richie · « **Reply #13 on:** 31 Aug 2013, 07:29 pm »

Good questions all of them.

capwkidd · « **Reply #14 on:** 31 Aug 2013, 07:40 pm »

Quote from: Danny Richie on 31 Aug 2013, 04:15 pm

Yeah, something like this:

It is actually the top woofer that crosses to the tweeter. The lower woofer gives some low frequency reinforcement only. These things image like you wouldn't believe. They create a great life sized sound field.

I think a lot of people have a tough time with the looks though. They don't understand it and it is too far from the norm.

What are those speakers called? I would like to hear them....

Can it be scaled up? Say, to the point of using 8's, or maybe as high as 15's?

Danny Richie · « **Reply #15 on:** 31 Aug 2013, 08:57 pm »

Quote from: capwkidd on 31 Aug 2013, 07:40 pm

What are those speakers called? I would like to hear them....

Can it be scaled up? Say, to the point of using 8's, or maybe as high as 15's?

They sound really good and they are a bargain. See them here: http://www.audiocircle.com/index.php?topic=110103.0

When you use an up firing omni driver you have to closely consider the diameter of the driver and where it's off axis response drops off. You have to cross it over to the tweeter in a range before it drops off. It still has to have output at 90 degrees off axis to the crossover point.

So with a 5.25" woofer you really need to cross it over no higher than 2.5kHz.

For a 6.5" woofer that figure drops to 2kHz. So you have to be sure that you have a tweeter capable of crossing as low as 2kHz.

If a woofer size were to shoot up to 8" in diameter then the crossover point would drop down to nearly 1.2kHz or less. Not too many tweeters will handle that.

And a 15" woofer is out of the question.

Jonathon Janusz · « **Reply #16 on:** 1 Sep 2013, 12:10 am »

Danny, I know "everything matters", but is the 45 degree angle on the tweeter baffle a must, or could a similar approach be had with say your x-omni, av-o, or 0-3 to add low frequency energy similarly? It isn't the looks that get me, it is just that the woofers in those just aren't my cup of tea sonically.

. . . and for those interested, here is the thread linking to the above speakers; Like Danny said, crazy good pricing:

http://www.audiocircle.com/index.php?topic=110103.0

Danny Richie · « **Reply #17 on:** 1 Sep 2013, 12:38 am »

Quote from: Jonathon Janusz on 1 Sep 2013, 12:10 am

Danny, I know "everything matters", but is the 45 degree angle on the tweeter baffle a must, or could a similar approach be had with say your x-omni, av-o, or 0-3 to add low frequency energy similarly? It isn't the looks that get me, it is just that the woofers in those just aren't my cup of tea sonically.

. . . and for those interested, here is the thread linking to the above speakers; Like Danny said, crazy good pricing:

http://www.audiocircle.com/index.php?topic=110103.0

The cool thing about the tweeter being laid over is that as you move horizontally the response doesn't change. In the vertical off axis the response doesn't change much either. It's actually pretty amazing how balanced they are off axis in any direction.

Mounting the tweeter at 90 degrees of the upper woofer doesn't have the same effect. It will drop off in the off axis just like any other speaker.

And because the woofers aren't having to play up too high, they actually sound pretty good.

A similar design can be done with other drivers though.

mlundy57 · « **Reply #18 on:** 1 Sep 2013, 02:44 am »

Like say a Neo 3 and M165X?

Mike

capwkidd · « **Reply #19 on:** 1 Sep 2013, 03:26 am »

Quote from: Danny Richie on 31 Aug 2013, 08:57 pm

They sound really good and they are a bargain. See them here: http://www.audiocircle.com/index.php?topic=110103.0

When you use an up firing omni driver you have to closely consider the diameter of the driver and where it's off axis response drops off. You have to cross it over to the tweeter in a range before it drops off. It still has to have output at 90 degrees off axis to the crossover point.

So with a 5.25" woofer you really need to cross it over no higher than 2.5kHz.

For a 6.5" woofer that figure drops to 2kHz. So you have to be sure that you have a tweeter capable of crossing as low as 2kHz.

If a woofer size were to shoot up to 8" in diameter then the crossover point would drop down to nearly 1.2kHz or less. Not too many tweeters will handle that.

And a 15" woofer is out of the question.

What about if you used the Neo 8 for the tweeter? It goes down to 500hz, right?