[Bayboy]

Uh oh

 

[turbo5upra]

8's play 50 cycles faster than 18's... What's not to understand?

 

[rton20s]

With a 5" you need the sub to play up higher then most 6" mid basses, that way it's better to have a small and fast front sub which plays the higher bass note's and a 15" in the rear to fill in the low end. And also it can cancel out some room modes so you have a better overall bass response! And easier to dail in a better curve in the low end.

WRONG.

I can see where this is going.

 

[Lanson]

Well not to get in a pissing match but, Tonny, have you read Dan Wiggins white paper on inductance vs. "woofer speed"? I'm not saying Dan had all the answers but the paper may help a great deal if you've not seen it.

And, as an owner of an ultra-low inductance Acoustic Elegance subwoofer, I can tell you that excepting cone breakup, a low inductance subwoofer, even a big one, can play higher frequencies just fine.

But we must first agree on what you meant by "speed", to properly understand what is going on.

 

[Bayboy]

LOL... high inductance won't even excuse that. Never heard a sub of any size have a problem playing above 50hz or even 100hz.

 

[Regus]

The one thing that always strikes me about this is the comparison with home audio. Whereas a typical 2-way bookshelf speaker can have the tweeter and midwoofer centre-to-centre spacing down to a few cm, this is rarely the case for factory car 2-way systems. Moving to 3-way can literally fill the gap between midbass and tweeter with a dedicated midrange and allow you to go to a larger midbass.

That said, I sometimes wonder if we are poorly served by trying to use the same drivers for a car 2-way as a bookshelf speaker - I like the idea of a 2-way with an 8" and 3" combination. If the really high frequencies were lacking, perhaps a small point source driver like that in the Kef hone cinema "eggs" would let you have your cake and eat it i.e. a 3-way that's about as simple as a 2-way in terms of install and time alignment...

 

[rton20s]

I like the idea of a 2-way with an 8" and 3" combination. If the really high frequencies were lacking, perhaps a small point source driver like that in the Kef hone cinema "eggs" would let you have your cake and eat it i.e. a 3-way that's about as simple as a 2-way in terms of install and time alignment...

C3CX + C8 is exactly what you are describing.

There have been quite a few builds documented here on DIYMA using point source drivers from Illusion, Morel, KEF and the like.

 

[Bayboy]

Home audio drivers aren't the problem. It's the room and listening position. Off-axis characteristics can not be denied. Of course there's times when we'd like to use some attractive raw driver that simply won't lend itself to our use, and perhaps some companies concentrate on certain aspects like JBL that supposedly designs with off-axis in mind. That changes things. Yet we also have tools to deal with such issues at a lesser expense than home audio.

 

[DonutHands]

Unless you are going 8, 9 or 10s up front in a 3 way I think its overkill and probably pointless if you select the right drivers.

A good 6.5 and 1" tweeter can cover what you need down till a sub takes over. There will be so much overlap with a 2, 3 or 4" midrange stuck in the middle there.

Also the trouble of driver placement, aiming and tuning.. the tuning is just so much harder with a 3 way in a car.

 

[rton20s]

Unless you are going 8, 9 or 10s up front in a 3 way I think its overkill and probably pointless if you select the right drivers.

A good 6.5 and 1" tweeter can cover what you need down till a sub takes over. There will be so much overlap with a 2, 3 or 4" midrange stuck in the middle there.

Also the trouble of driver placement, aiming and tuning.. the tuning is just so much harder with a 3 way in a car.

I went from a 2 way with a good (read: capable of a fairly low high pass) 1" tweeter and 6.5" mid to the same with the addition of a 3" midrange and it made a significant difference. If limiting yourself to stock locations (save for tweeters), it can be quite tough to get a 2 way to sound as good as a 3 way. Yes, even taking into account the added complication of tuning the 3 way. All of this is, of course, vehicle dependent.

 

[ErinH]

8's play 50 cycles faster than 18's... What's not to understand?

of course!

 

[ErinH]

C3CX + C8 is exactly what you are describing.

There have been quite a few builds documented here on DIYMA using point source drivers from Illusion, Morel, KEF and the like.

look at the termination of the tweeter to the mid on the c3cx.

in a coax/concentric, you want the midrange/tweeter transition to be as smooth as possible and also to not cause the mid to move (thus a high-pass filter).

This termination on the illusion c3cx above is very poor*. the tweeter sticks out above the mid's cone and there is no semblance of an attempted waveguide to help smooth the tweeter's HF response. which guarantees comb filtering issues (akin to what the review of the small bookshelf coax you posted earlier has).


*I'm not saying in X person's car they don't sound good. Lord knows everyone wants to take that out of what I said. I am simply talking about the design of the driver and an obvious flaw. Whether or not that makes an audible difference to people is up to them.

 

[1fishman]

By the way these things are Garbage! FWIW

Edit. you can have mine for $15 if you want to try them yourself.

Go ahead, be the guinea pig, I dare you! They're only $40.
Amazon.com: Micca COVO-S Compact 2-Way Bookshelf Speakers: Electronics

 

[rton20s]

look at the termination of the tweeter to the mid on the c3cx.

in a coax/concentric, you want the midrange/tweeter transition to be as smooth as possible and also to not cause the mid to move (thus a high-pass filter).

This termination on the illusion c3cx above is very poor*. the tweeter sticks out above the mid's cone and there is no semblance of an attempted waveguide to help smooth the tweeter's HF response. which guarantees comb filtering issues (akin to what the review of the small bookshelf coax you posted earlier has).


*I'm not saying in X person's car they don't sound good. Lord knows everyone wants to take that out of what I said. I am simply talking about the design of the driver and an obvious flaw. Whether or not that makes an audible difference to people is up to them.

Understood. And of all of the people on this forum, I would guess that you probably have the most intimate knowledge and experience with concentric drivers.

While I can see that there are shortcomings in the design of the Illusion drivers, in my experience they still perform pretty well. Certainly better than the attempts at tweeterless installs using "fullrange" and midrange drivers.

Maybe if you need a really small concentric, the better options is to buy one of these and crack it open like an egg to get at the good stuff on the inside?

 

[rton20s]

By the way these things are Garbage! FWIW

Tell us how you really feel.

Did you purchase a set or where did you hear them? N/M saw that you ninja edited the answer.

I might be picking up a set of the MB42Xs as a gift for my brother to use in his garage. Much better reviewed speakers than the little COCO-S.

 

[benny z]

While I can see that there are shortcomings in the design of the Illusion drivers, in my experience they still perform pretty well. Certainly better than the attempts at tweeterless installs using "fullrange" and midrange drivers.

*cough*

 

[benny z]

You got any YouTube videos?

 

[turbo5upra]

You got any YouTube videos?

We already know yours is bigger.

 

[rton20s]

*cough*

Someone having a hernia exam?

 

[ErinH]

Why? Put a capable sub up front and call it a day.

Something about such a configuration seem mighty familiar to me. Can't quite put my finger on it.

With all due respect to Linda, that photo is a bit misleading in the context of your post. She got world champion in install in her particular class. Not the sound quality portion event.

Not trying to poo-poo on how she did in the sound Q portion of the event. Just making the clarification to misleading post/photo combination.