Cynosure Project

[GBBinaural]

Let me start of by saying that I have never built a DIY speaker project. I recently learned about this website so I figured I would bounce a few questions of of the experts to see what kind of feedback I get.

I am leaning towards building the "Cynosure" project that is posted on Parts Express:

http://www.partsexpress.com/projects...sure/index.cfm

I have concerns about the frequency response graph of this project:

Frequency Response

What I am interested in is what you all think of this project. I like the idea of the wide, very low profile enclosure. I am open to other speaker options.

Also, I believe that I will build JUST this center channel at first but what do you all think of possibly mating this speaker with some surrounds? Can I do a MTM or a MMT, or a MMMT using the same drivers? I really don't know what I am doing...YET so I am just hoping that these forums will help me end up with a successful DIY project.

Thanks

[GBBinaural]

Bump...

My concerns about the frequency response is that it varies from ~84db to ~91db. That seems like a bit much but I am a newbie so I am hoping that someone can decipher it a bit for me.

Thanks

[planet10]

My opinion: MTMs already have issues. The person who gave us sideways MTMs shoild be pilloried... This one just makes everything worse. A single one of the TBs should be better sonically.

The FR isn't all that bad... ignore the LF bump and it is ~+/- 3dB

dave

[GBBinaural]

Well...at least you are honest. Do most people feel that way about horizontal MTM's? This particular project does state that it turned out to have exceptional off axis performance. The crossover design is limiting each "pair" of speakers (outside, middle, inside) to a certain range does that help at all with your extra disdain since this is a MMMTMMM design?

I really appreciate the response. I am open to ANYTHING really...I just know that I want a nice sounding center channel that I can incorporate into a fireplace mantle. That is why it needs to be low profile.

As far as the frequency response goes. It may be not be "all that bad" but is it something that should be a good bit better if possible?

[planet10]

Originally posted by GBBinaural
Do most people feel that way about horizontal MTM's? This particular project does state that it turned out to have exceptional off axis performance. The crossover design is limiting each "pair" of speakers (outside, middle, inside) to a certain range does that help at all with your extra disdain since this is a MMMTMMM design?

A lot of people feel the same as i about horizontal MTMs (i'm personally not a fan of vertical MTMs either), but a lot of people are also swayed by the fact that there are so many hirizontal centres out there (only way the manufacturers can fit something that looks like the surrounds on top of the TV. "More drivers has to be better doesn't it..."

The power tapering certianly means the designer thot about the problem, The exceptional off axis is probably in the vertical... the whole idea behind an MTM is to get symetrical and limited vertical dispersion and wide horizontal dispersion... turning it on its side is counter to the whole concept.

I really appreciate the response. I am open to ANYTHING really...I just know that I want a nice sounding center channel that I can incorporate into a fireplace mantle. That is why it needs to be low profile.

I'm a full-range guy. I'd say get an FE127 and put it into the 4.5 liter box... actually i firmly hold that -- given you aren't jamming people into the "poor seats" -- that no centre (ie a virtual centre) is the best centre.

IAs far as the frequency response goes. It may be not be "all that bad" but is it something that should be a good bit better if possible?

Have a look at the real world measurements of some of the big buck speakers in stereophile or hi-fi news... FR is just one of many important parameters in a speakers performance... and in the immortal words of Ed Schilling "i can make the measuremenst look anyway i want"

Further, if that FR is a measure and not a sim, everything below 300 Hz has to be taken with a grain of salt (maybe a whole box given we don't know their context)

Whenever i see a speaker with a passive XO & ruler flat FR i start getting worried... if the XO is simple i consider it excellent design... if it is complex then i wonder how much of the life of the speaker has been sucked out of it.

dave

[Scottmoose]

True. If you really want a centre channel (as a fan of 1970s Quad I'm with Dave -they improve dialogue imaging for off-axis viewers / listeners, beyond that, I can live cheerfully without them), then a 127 or 167 in a sealed box would be a good choice providing you're not trying for 120db peaks. I don't like horizontal arrays of drivers like that -dispersion is not going to be great IMO. Still, YMMV. Some people like them, though that might be because they haven't heard anything else? The 'stretching' of the image can be rather disconcerting, to my ears.

Ed's right about the FR graphs. Admiral John Fisher once commented 'When I was Controller, I had an excellent secretary. When I asked him for facts, he asked me what it was I wanted to prove! There is no doubt facts are most misleading.' Beware taking them at face value, unless you have the background detail / context, and also know how to interpret from that what is happening and why.

[GBBinaural]

I am continuing to learn more and more about loudspeaker design. I appreciate all of the responses so far. I have a new question now. I would like to input this project into a software solution (Speaker Workshop). Would it be possible to actually do that in this free software given the complexities of this speaker? Below is the crossover design:

Crossover - Cynosure

Can this crossover be constructed in Speaker Workshop? I am a total newb so if anyone can walk me through this process that would be great.

Thanks

[badman]

These are typically terrible designs. Most of their 'designers' don't address the serious issues of diffraction, baffle step, other stuff.

Better diy is out there, projects like those at www.zaphaudio.com are a good start.

[Godzilla]

I dont have these anymore but they worked great in a 5.1

http://www.zillaspeak.com/recycledsystem.asp

TB Bamboo's are currently my left and right in my home theater system.

http://www.zillaspeak.com/Bamboo.asp

i would keep them and make a center also using one TB Bamboo driver. They are less fatiguing when used with solid state - like my cheapie Yamaha receiver - than any of the Fostex i have heard.

Just my 2 cents.

Godzilla

[GBBinaural]

I appreciate the fast response. I have taken a look at some of Zaph's projects and they seem to be well executed. I am however in a bit of a spot and I really need the overall style (IE...long short design) of the cynosure project since it is going to actually BE my fireplace mantle. What I am trying to do is get THAT project into a loudspeaker design software package so I can begin to learn what happens to response curves when the crossover and or speakers are altered. I am not dead set on building that exact project but it will be something very similar. Any help on how to build that type of crossover in Speaker Workshop would be great.