# center channel tweeter and woofer in-line



## cloudbuster (Apr 22, 2011)

Hello I read that most of the center channels with tweeter inline with the woofer dont sound as good.
but cant seem to find that discussion.
what are you guys toughs.
thanks.


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## robbo266317 (Sep 22, 2008)

Hi, welcome to the shack. 
Do you have any particular drivers/designs in mind for the centre? Or are you looking for commercial units?


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## Jungle Jack (Jul 28, 2009)

cloudbuster said:


> Hello I read that most of the center channels with tweeter inline with the woofer dont sound as good.
> but cant seem to find that discussion.
> what are you guys toughs.
> thanks.


Hello,
Speaker Design is one of those things where not everyone is going to be in agreement. I will say that KEF and TAD (Pioneer's uber expensive Speakers) both use Concentric Drivers in some Models in which the Tweeter is housed inside the Mid Range Driver and are some of the most highly regarded Speakers in the World.
Cheers,
JJ


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## cloudbuster (Apr 22, 2011)

I was looking at commercial units, but I have alot of tabs open on my firefox when I search for stuff and i read something like that the people complaining about their center speaker that they all have everything in-line.
then I got scare away from those unit but I guess is irrelevant. maybe bad setup from their part.


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## Jungle Jack (Jul 28, 2009)

Hello,
If you could provide us with some Center Channels that you are considering, perhaps we can shed more light on the subject. Some Speaker Designs use First Order Crossovers and a staggered Woofer Array so that all of the individual Drivers arrive at the listener at the same time. Thiel uses this approach on their Designs for instance.
Cheers,
JJ


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## drdoan (Aug 30, 2006)

Welcome to the Forum. Have fun. Dennis


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## browndk26 (Jan 3, 2011)

Read this, it may be what you are asking about.

http://forum.blu-ray.com/speakers/8...channel-speakers-why-they-should-avoided.html


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## GranteedEV (Aug 8, 2010)

cloudbuster said:


> Hello I read that most of the center channels with tweeter inline with the woofer dont sound as good.
> but cant seem to find that discussion.
> what are you guys toughs.
> thanks.


Dunno where you heard that. I would say that coaxial drivers make some of the best center channels out there thanks to their controlled, but even dispersion and minimal "crossover lobing". They can be tricky to design because the tweeter, when placed inside the woofer, becomes "acoustically loaded" - like a horn. Most coaxes are thus effectively waveguides, which in turn means that there's a natural shift away from flat response. this can be somewhat rectified mind you, but it takes an experienced designer and lots of measurements. Speaking of experienced designer, how about Mark Seaton, who uses digital, active filters on his sweet sweet speakers?

Here is an owner who said that the Seaton Catalyst is the best Center he's ever heard:

http://www.seaton-sound-forum.com/post?id=3098564

and such a speaker has of course inspired many to try their own hand:

http://www.hometheatershack.com/for...new-3-way-build-ae-woofers-b-c-mid-tweet.html

The Pioneer S-7EX is another sweet coaxial center channel - I'm a big fan of Pioneer speakers and it's kind of surprising they're not all too popular or widely available considering it's by no means a small brand and their products are top-notch. I can only imagine how great TAD speakers sound... I can only dream of buying the $7000/pair beryllium compression driver, never mind the whole speaker :rofl: Either way, the heart of a speaker is the crossover and Pioneer coax speakers sound unbelievably neutral. 

Another speaker which I think is a sweet deal is this guy - the Seas Loki DIY Kit:

https://www.madisound.com/store/product_info.php?cPath=35_40_402_275&products_id=8767

Although a single 6.5" driver may not have the desired midbass output... i'll return to this in a sec.

So what is the main drawback of a coax? I would say it's a function of how loud you plan on pushing the thing. As the cone moves in an out, it creates intermodulation distortion of the tweeter's own output. With only a bit of cone movement, it's essentially inaudible but as the excursion of the coax increases you might get some change in the sound. 

That's why I like the seaton approach of supplementing that 8" coax with some woofers. By letting the woofers handle things like baffle step compensation and upper bass (80hz to 200hz or so for example) you really reduce the excursion of the 8" coax at high volumes. THat's probably the biggest drawback on that seas loki... asking a single 6.5" driver to handle all the way down to a subwoofer crossover is rarely a great idea. A better solution at the very least add a second woofer for a 2.5 way. TLS Guy over at the audioholics boards did this exact thing in his reference level DIY center speaker:

http://mdcarter.smugmug.com/gallery/2424008_RKGvb#127077317_Pufg7

But I don't know how many people could have such an unconventional center (it also happens to be a large transmission line speaker). Such a build is for the experienced DIYer, i'm sure.

If I had to pick a coax driver to build a DIY speaker out of, the B&C used by zeitgiest, and the Seas Prestige above would be my options. The KEF coax driver is good too, but i've already been told the Seas Prestige T18RE measures a bit more cleanly. 

At the end of it all though, the crossover design determines a strong percent (80?) of how a speaker sounds. It's easy to make a coax sound bad with a weak crossover -, just like any other speaker. Either way, if you're not planning on listening at total reference levels, I don't think there's a better solution for a center channel out there than that Seas Loki, at least not until, price-wise you get to the JTR Triple 8, JTR Triple 12, and maybe some more vertical non coax options like a JBL 6328, Geddes Abbey etc. 

To conclude: Good dual concentrics make sweet center channels. They don't have superwide dispersion which interferes with the mains, they don't have crossover lobing like MTMs and even WTMWs, they have reduced ceiling and floor reflections, and the power response can be very good, meaning a wide sweet spot within its dispersion pattern.

Center channels aside, I really, really badly want to hear the KEF 207/2... I've heard it compared to the Revel Salon2 which in my opinion is a world class speaker - so that's extremely high praise.


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## Jungle Jack (Jul 28, 2009)

Hello,
I am a huge fan of Mark Seaton and his Center Channel looks to be an excellent one. If you can afford TAD's, that is the direction I would go however. While Seaton makes excellent products, TAD has the R&D backing of a Multinational Corporation coupled with cost no object Speaker Construction.
Cheers,
JJ


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## GranteedEV (Aug 8, 2010)

Jungle Jack said:


> If you can afford TAD's, that is the direction I would go


The Mortgage Office at the bank supports this :spend: :spend: :spend: :spend: :spend:


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