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Discussion Starter · #1 ·
In a previous post I showed a design for the 3 way flax set from focal that turned out to make too much of a blind spot off the a pillar so I decided to make them concentric instead. I want to highlight the power of using 3D printing with ABS to easily transform any set of mid and high, combine it with its respective crossover and delay, and get an absolutely amazing result for the ears and eyes; concentric sources and smaller real estate. The 2nd picture shows a piece that will be wrapped in fabric to act as a grille. It is attached with 4 small magnets around the arches.

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I'm sorry if I missed the other post, but I would like ask if you are willing to share your thoughts about if this mounting method has any sonic tradeoffs with a standard baffle configuration.

Did you see any sonic benefits doing something more of a Bullet shape for the back of the tweeter cup or a classic tear drop shape?

Does it sound different having the tweeter in front? How have you compensated for things like Phase cancellations and anomalies.

Have you thought about doing it Backwards? Say for example using a tear drop shape behind the mid range, and then having the tweeter behind it in a wave guide? That would seem to work better on paper I think as the physics play out that way with some drivers.

Very good work. Now take better photos! LOL! They look like they took some time to make. Show the off!
That's and ORDER!

Good work by the way!



Last question if you will. How does that tweeter sound on and of axis? Do you think the inverted dome is better then the typical dome tweeter, and how does it compare with other tweeters that you have experience with?
 

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sorry, not digging that at all. u plan on mounting that in an a pillar
 

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Discussion Starter · #4 ·
I'm sorry if I missed the other post, but I would like ask if you are willing to share your thoughts about if this mounting method has any sonic tradeoffs with a standard baffle configuration.

Did you see any sonic benefits doing something more of a Bullet shape for the back of the tweeter cup or a classic tear drop shape?

Does it sound different having the tweeter in front? How have you compensated for things like Phase cancellations and anomalies.

Have you thought about doing it Backwards? Say for example using a tear drop shape behind the mid range, and then having the tweeter behind it in a wave guide? That would seem to work better on paper I think as the physics play out that way with some drivers.

Very good work. Now take better photos! LOL! They look like they took some time to make. Show the off!
That's and ORDER!

Good work by the way!



Last question if you will. How does that tweeter sound on and of axis? Do you think the inverted dome is better then the typical dome tweeter, and how does it compare with other tweeters that you have experience with?
Hey Mickey thanks for the comments. As long as you are willing to accept a slightly lower than spec’d xover point for the 3in and tweeter you see here, then there’s really no tradeoffs. With a 3 inch woofer beaming can start to occur around 2k but most people wouldnt notice the effect on an A B comparison till around 3k or higher.

The bullet shape you refer to may help with some turbulence but id have to pull the tweeter even farther away from the 3in to result in the same air space i have in front of it. My main goal was to maximize the front air space and minimize the height of the tweeter, for space reasons. Positioning of the tweeter was done with an initial tweeter baffle print and my ears.

Phase becomes your best friend in this configuration. With this configuration i have, on average, more area in the car to sit where the alignment is good. In a standard side by side baffle configuration your perfect alignment will only ever be in one plane, hopefully it intersects with the driver seat. In this configuration I’ve created an invisible cone which can have correct alignment everywhere inside it.

Personally I think the tweeter must be in front, if you cant see your tweeter with your eyes you aren’t hearing it all with your ears. I’ll never understand why someone would mount a tweeter not only farther away than the mid but lower than the mid as well, unless for space reasons. Tweeters are on the top halves of studio monitors for a reason. The inverted dome is nice and up until recently was mounted far off axis. It works, but if you want audiophile then you need it pointing much more towards you.

And the pics! I know, I’ll have more this week, the 3in baffle is currently fiberglassed into place. Filler coming up but unfortunately i can’t let the house smell like filler on Mother’s Day!
 

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Discussion Starter · #5 ·
sorry, not digging that at all. u plan on mounting that in an a pillar
Really? I like Porsches though!

The final result will look like a half sphere wrapped in black grille cloth. I think it looks different but it should fade away nicely when looking at it dead on from front seats.

More pics to come this week.
 

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Discussion Starter · #9 ·
I love the concept. Any issues with the crossover between the 2?
Haven't noticed with the ears yet, I'm crossing over at 2750 for MF and 3k for the HF. The waveguide I put on the HF boosted the 2-3k range so I had to back it off a little in the crossover. I'll be measuring with RTA next week to really dial in the crossover and delay. I'll ultimately end up going with what my ears like but it's good to get a good reference to at least get me close to the best answer
 

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Discussion Starter · #10 ·
I think the experimentation is awesome...trying new things, especially in a car. It looks like the tweeter covers a large portion of the midrange. How does that affect the sound from the midrange?
It doesn't at all as long as you crossover below the beaming point for the 3 inch woofer. The beaming effects were noticeable at 3k. The 3 inch woofer's crossover is set at 2750 24db/oct but this may change after testing with a microphone.
 

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I really like this idea and would love to see it implemented with a mid bass and a wideband

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That would be tough, a wideband will need to be pretty much directly on axis if you want any sort of high frequency output, which means the midbass will also have to be on axis. It's not super easy to put a 6.5", or similar, sized speaker on axis in a car.
 

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Hey everyone here are the pictures of how it came out! Concentric sources sound amazing and the experience for everyone in the car is much better.
 

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What are your thoughts on a wire mesh grille? I’m not feeling the grill cloth. Would love to see an rta.
 

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Seems like a lot of work to achieve the same thing that has been done before with certain components or coaxials (exact memory eludes me at the moment, but same concept). What say you? Less interference, better way to hide wires, etc.


Concentric... no. Nifty with the right drivers... super small tweet... yes. Essentially a coaxial.... yep.


Man & Machine... Power Extreme!
 

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Discussion Starter · #17 ·
Seems like a lot of work to achieve the same thing that has been done before with certain components or coaxials (exact memory eludes me at the moment, but same concept). What say you? Less interference, better way to hide wires, etc.


Concentric... no. Nifty with the right drivers... super small tweet... yes. Essentially a coaxial.... yep.


Man & Machine... Power Extreme!
Essentially a coax yes, but unfortunately for me with a small dash, they did not come this way from the manufacturer. I already had the speakers so a solution was needed to solve my huge blind spot. Having them side by side was not a good option. They are concentric sources because they are coincident about the same axis. They are also delayed digitally to pull their source of sound to the same plane and make it seem like they are one source. Concentric and coaxial are interchangeable. It just means two axes coincident with each other, the theoretical 2D objects normal to those axes do not need to be on the same plane to be called concentric. The delay is what creates a better sum between the two at the crossover, reducing the effect of the phase issue due to the distance between the drivers. Loudspeaker companies have been doing it for years, nothing new here.

The project in general also became a lot easier when I only had to fiberglass one small baffle into place. That made me a happy camper.
 

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hate to be that guy, but i really cant picture this sounding good
Maybe offer to remote tune it for him at a discount so that you can find out ???

I think its awesome that he is playing around with these ideas...gets back to the roots of diyma, which I sorely miss!!!
 
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