# carver 48" ribbon based center channel



## angelod307 (Oct 18, 2007)

hello all, i am looking to build a center channel to compliment the al-III ribbon dipole speakers that i have in the rest of the system. just for kicks, i took one of the six that i have and laid it sideways for a center channel trail. well, it failed horribly. it sounded like nothing more than a over glorified tv speaker. thin is an understatement here. so, at the very least, my thoughts are a couple of 10" maybe even 12" midbass drivers in a ported cabinet that has the ribbon in a sealed back enclosure with a wide dispersion horn for the treble that needs to have a little sizzle for the movies like in the theaters. anyhow, any body else have any experince with the carver amazings and a center that matches the timber closer than not. cheers, angelo


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## Lucky7! (Jan 7, 2008)

Could you please add a link for your current speakers as I'm not sure I've ever heard of them and it would be easier to make suggestions on your centre channel if we knew what you were working with.

I'm guessing you want to use the 48" tall ribbon elements as part of the CC design; is that correct?


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## angelod307 (Oct 18, 2007)

yes, the 48" driver mounted sideways under my screen. let me look for my stereo link here.


http://www.hometheatershack.com/for...-equipment/7063-old-school-theater-power.html


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## angelod307 (Oct 18, 2007)

here is my link. although the equipment has been updated to use two tfm55's and two tfm35's as well as a carver 490t cd player with a jolida jd700mkII dvd player to replace the yamaha dvd. soon i am gonna put back my 2 channel system as well. a sonic frontier sfl-1, jolida jd100se cd player with a set of homemade 7" and ribbon transmission line speakers played from another two tfm35's. but for now, the center channel is what i need to focus on. i am tired of the eye sore that i get from the 6 klh speakers with the boston acoustic center and a horn. i think it will end up being an experiment from start to finish as i have not seen anybody do it and document it as well.


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## 1Michael (Nov 2, 2006)

Where is the link?


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## engtaz (Jul 9, 2010)

Link is in post 3.


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## mdrake (Jan 31, 2008)

Those ribbons are NICE. I am not sure how well a compression driver would blend with a ribbon. You might be better off getting a high quailty ribbon tweeter like a Raven to build a DIY center. 

Matt


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## angelod307 (Oct 18, 2007)

mdrake said:


> Those ribbons are NICE. I am not sure how well a compression driver would blend with a ribbon. You might be better off getting a high quailty ribbon tweeter like a Raven to build a DIY center.
> 
> Matt


yes, i might / might not. i find that movies just do not sound right without a horn there. seem kinda flat. domes tend to be soft, metal type tend to sizzle, but horns just add the right crisp sound. crossed over past 4k though. i think the piezo horn i have now is even higher than that, with a cotton ball or two stuffed in the throut to make it blend better. i just installed some dayton poly caps in my mains today, wow. i can't wait for them to break in. even now they are so much more relaxed than the originals. more musical and laid back. effortless come to mind. 75ufx2 for the high pass wwith another 75uf in the notch/step filter. cost a bill, but again, wow.


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## angelod307 (Oct 18, 2007)

also, i have a set of the newer ribbons that bob carver designed. they might take over that duty as well. so i am not 100% on the horn. i shall see.


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## maxserg (Dec 11, 2008)

I don't understand!

You want to use a long ribbon in the horizontal position under the screen?
The ribbon when used vertically has a good horizontal dispersion and a verry narrow vertical dispersion. When put sideways it sucks.

What is the freq response of this ribbon without flanges?

There is a good chance that the bass/low mid are missing.

Just my thinking...


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## angelod307 (Oct 18, 2007)

you are correct on all. this is why i am curious if anybody elso has attempted such a task. as i have said, the ribbon will be closed back, and i might even try to use a newer style 6" ribbon and/or many of them to accomplish my goal. all i know is that there is not any kind of cohersion from left to center to right otherwise. you know the saying, i want my cake and....i wanna eat it too. the only plus on the horizontal mount of a 48" driver is that it is 48" so the vertical is kinda covered. just laying it like it is really sucks. there is no depth to it at all. it sounds very hollow and thin. at the moment with 6 - 8",4",cone tweeters plus the 5.25 mtm center and a horn to top it off, it sounds nice, but not the same as the other speakers. r&d is needed to remidy the situation.


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## maxserg (Dec 11, 2008)

So maybe the Raven ribbon (shorter) *vertically mounted* with low/mid end speakers.

Anyway I think that the use of a ribbon tweeter as a center channel can be tricky to implement(dispersion wise) with cones

My 2 cents


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## maxserg (Dec 11, 2008)

If you want "ribbon" sound on a center channel(3way) look here: http://www.speakerhobby.com/centerspeaker.htm


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## Lucky7! (Jan 7, 2008)

angelod307 said:


> you are correct on all. this is why i am curious if anybody elso has attempted such a task.


Not that I've ever seen, but it's not the best way to go about it anyway. As you move off axis comb filtering will occur, which is what you're getting with the "there is no depth to it at all. it sounds very hollow and thin" comment. Either mount and use it vertically behind an AT screen, or look for another approach. 

I'm not even sure at the moment what approach to suggest to get a similar tonal balance, especially power response to what you have for the L/R. Phantom centre might be the best option.


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## angelod307 (Oct 18, 2007)

yeah, phantom is good, but even the center i use now sounds more like the theater sound. the link to the center with a ribbon tweeter is a thought as well. the little ribbons i am refering to are made by hifi/swan. they are the ones that sunfire uses. dayton offers one of them as well as others. i think that using some papaer drivers, 2 to 4 - 12"s crossed over around 200-300hz in a ported box tuned around 40-50 hz, with the 48 ribbon doing the rest in a sealed back enclosure. then maybe a horn or little swan ribbon to add some of that crisp timber that you hear at the big screen. the only person thin will impress is me, as i sit in the sweet spot at all times. now with all those drivers spead across the bottom of the screen, i just get one full sounding center. for that matter, the 12's may even stay in a sealed box. other thoughts include puting 2 of the 12" woofers firing foward with the other 2 firing backwards with the ribbon in a dipole cofiguration. lots of research to be done on my end. this has been a though since i bought the ribbons in the early 90's.


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## Lucky7! (Jan 7, 2008)

Even sitting dead centre and not moving, you are going the have combing issues with a wide radiator' the path length differences between the sound radiated from the centre of the diaphragm (shortest path to your ears) and the ends (longest path). If you move around slightly, it will vary even more.

The centre linked a few pots back looks like a good design and would be a better choice than the Carver laid horizontal. No guarantee it will sound remotely like your L/R, but neither will the other design you suggested.


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## angelod307 (Oct 18, 2007)

yeah, the other option is using some 30" ribbons in a vertical mount or the smaller 6" ribbons in a simular way.


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