Driver choice for center to accompany ScanSpeak fronts

[vin23]

Hi all,

I'm building a center speaker to accompany a pair of fronts with ScanSpeak drivers. (http://www.speakerenco.nl/content/lu...s_zuil_03.html)
The fronts use a D2905/99000 tweeter, 18W8546.01 midrange and 18W8545.00 woofer.
Since it will lay flat (and because of the ever-present WAF, it has to suit the cabinet ) I'd like to use 2 4-6" midranges and a tweeter with a 3-4" outer diameter. I'm thinking about a MTM-alignment with the tweeter slightly above the centerline...

Here comes the problem: I have no idea which drivers sound best with the ones in the fronts...

[sreten]

Hi,

The alleged driver matching required for a centre is mostly myth.

This might be interesting :
http://www.humblehomemadehifi.com/do...Mk-II_copy.pdf

rgds, sreten.

[camaro71]

Originally Posted by vin23

Hi all,

I'm building a center speaker to accompany a pair of fronts with ScanSpeak drivers. (http://www.speakerenco.nl/content/lu...s_zuil_03.html)
The fronts use a D2905/99000 tweeter, 18W8546.01 midrange and 18W8545.00 woofer.
Since it will lay flat (and because of the ever-present WAF, it has to suit the cabinet ) I'd like to use 2 4-6" midranges and a tweeter with a 3-4" outer diameter. I'm thinking about a MTM-alignment with the tweeter slightly above the centerline...

Here comes the problem: I have no idea which drivers sound best with the ones in the fronts...

very nice and interesting links
There are beautiful speakers.
There are projects for the DIY or you can just buy things?

regards Caesar

[vin23]

Wow, beautiful driver and nice speaker!

With the current setup the center speaker is very audibly different from the fronts. The fronts sound very open, clear and slightly warm, while the center (an Eltax Something-center) sound harsh and obtrusive (i hope you catch my drift... ). In any case, you can clearly hear the difference...
While this may be a rather extreme combination of different-sounding speakers, i'dd like to match them integrate them as seamlessly as possible in the sound created by the ScanSpeaks.

This will actuallty be the first speaker i'll design myself... I've built a few kits before, but for this one i'dd like to do the cabinet- and crossover-design myself.

For now I think I'll stick to the MTM-arrangement, since I'm quite a sucker for aesthetics. I will post some renders in a while, then I'lll explain my point further

The fronts are available as drivers, drivers+cut wood and fully assembled. Instructions were clear and sufficient, and the resulting speakers sound awesome. I'dd recommend them to anyone

[sreten]

Hi,

Designing a center has even more pitfalls than normal speakers.
Some decent info about them and discussions in Zaph's site.

Why people even bother with them with good L+R's is beyond me.

rgds, sreten.

undefinition (see if nothing else, the excellent FAQs)
A Speaker project
The Speaker Building Bible - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com
Zaph|Audio
FRD Consortium tools guide
http://web.archive.org/web/200909021...esigningXO.htm
RJB Audio Projects
http://web.archive.org/web/200909022...ve99/Spkrbldg/
Speaker Design Works
HTGuide Forum - A Guide to HTguide.com Completed Speaker Designs.
DIY Loudspeaker Projects Troels Gravesen
Humble Homemade Hifi
Quarter Wavelength Loudspeaker Design
The Frugal-Horns Site -- High Performance, Low Cost DIY Horn Designs
Linkwitz Lab - Loudspeaker Design
Music and Design

Great free SPICE Emulator : SPICE-Based Analog Simulation Program - TINA-TI - TI Tool Folder

[vin23]

Nice, awesome links! I'll study them in detail tomorrow...

The reason why I want to build a center is mainly to improve the 5.1 system that is currently in place. Besides that there is a remarkable difference in soundstage between using just the fronts and the fronts+center. There isn't a fixed listening position in the room (deviation is +- 2 meters) and using the center the sound remains more constant while moving around the sweetspot.

Attached are some renders of a quick mockup...
Final dimensions are higly subject to change, but please feel free to point out any pitfalls you see; To me it seems better to solve them using proper cabinet design than to rely on crossover adjustments.

I'm going for a MTM-design mainly because my clients (read: my dad & his wife) were much more supportive of the MTM in comparison to a Fullrange solution.
Fullrange would definitely be a possibility (audio-wise) but is a lot more difficult to integrate aesthetically. To balance out the lines in the design (of the humblehomemadehifi-center for example) i'dd have to add some detailing to either the top or bottom of the speaker (depending on the placement of the ports). Since I don't want to use much 'fake' paint-decals but rather rely on a form-follows-function-approach, the detailing of the cabinet can't get any more complicated than can be accomplished using hand-guided routing, sawing and bending.

And yes I know, I'm following a bit of a top-down approach But to my limited knowledge (I just started reading the Loudspeaker Cookbook again) it should be possible to make this visually-oriented design sound good

[sreten]

Hi,

Well it certainly seems like its going to look nice if nothing else.

Look at the MTM centre versions of the R+L MTM's in the links, including
Zaph|Audio - ZA5 Speaker Designs with ZA14W08 woofer and Vifa DQ25SC16-04 tweeter

rgds, sreten.

[vin23]

Haha, I think I've got the 'looking nice'-part covered. Now on to the more important parts of loudspeaker design

But damn, the more I look, the more the MTM-center concept seems fundamentally flawed. There seem to be a lot of nice band-aids to correct flaws, but all of them are using concepts I'm only just beginning to understand.
I do like a challenge, but also a good foundation, definitely since this will be my first full design. It does kinda seem like I'll have to get back to the drawing board

The center from Zaph Audio looks really nice though, i'll do some proper reading and interpreting when it's not 1:30 AM

[Shaun]

Originally Posted by vin23

But damn, the more I look, the more the MTM-center concept seems fundamentally flawed

With your stated ambitions, I'd recommend going or a design that is W-TM-W (with tweeter above the mid). I came to the same conclusion as you did, though I never completed my own project.

Here are some examples:

HTGuide Forum - CJD Khancenter - a RS180/RS150/RS28A Center
Mozambique

[RockLeeEV]

I recommend a "CW" 2.5 way or 3-way center.

using This coaxial tweeter/midrange:

Speaker Exchange | KEF 8″ Q900 Coaxial Driver