Center Speaker configuration

[billleeder]

Hello,

I am considering ordering parts for a center channel speaker and have the speaker built by someone who recommends the following:

1 DAYTON MTM-1.0BK 1.0 CU FT MTM CABINET
2 Adire Audi Extremis 6.8- 6.5" mid bass speakers
1 MOREL MDT-44 COMPACT SOFT DOME TWEETER
1 DAYTON XO2W-3.5K 2-WAY CROSSOVER 3,500 Hz
1 GOLD HIGH POWER TERMINAL RECTANGLE

After talking to Parts Express, they questioned if this was a good configuration and suggested I post a message on Tech Talk. Does anybody have any opinions. I am a complete rookie at this stuff.
Thank you,
Bill Leeder

[paul_n_oneal]

You were doing good until you hit the text book crossover which will probably not work. You need to hook up with RomanB who has used this woofer before. He recommened that you use two because the efficiency is real low like 80db when BSC is figured in. I'm sure that he will lead you in the right direction. BTW, that woofer, from what he says is just downright awsome for bass reproduction. For a 6.5" it has tremendous bass. His web site is here so you can check out his projects and email him:
<A HREF="http://www.rjbaudio.com/">http://www.rjbaudio.com/</A>

[natman]

> Hello,

> I am considering ordering parts for a center
> channel speaker and have the speaker built
> by someone who recommends the following:

> 1 DAYTON MTM-1.0BK 1.0 CU FT MTM CABINET
> 2 Adire Audi Extremis 6.8- 6.5" mid
> bass speakers
> 1 MOREL MDT-44 COMPACT SOFT DOME TWEETER
> 1 DAYTON XO2W-3.5K 2-WAY CROSSOVER 3,500 Hz
> 1 GOLD HIGH POWER TERMINAL RECTANGLE

> After talking to Parts Express, they
> questioned if this was a good configuration
> and suggested I post a message on Tech Talk.
> Does anybody have any opinions. I am a
> complete rookie at this stuff.
> Thank you,
> Bill Leeder

Let me be the first of many to explain that even though a store bought crossover is an appealing idea, in practice they rarely match the drivers well enough to provide a satisfactory result.

I would suggest that you look for a speaker design in the project page that includes a custom crossover designed by someone who knows what they are doing.

[cjd]

Folks have already hit on the stock crossover which will probably sound pretty bad.

I think the box may be on the small side for the Extremis as well, though keeping it sealed may mean it's not too bad at all.

Regardless, the other issue you will run into is that for a center channel, if you do an MTM you want as LOW a crossover point as you can get. Or you want a WTMW with the TM vertically aligned and the woofers flanking.

With the driver selection you have, you're probably talking 1.2kHz crossover - not sure if that tweeter is up to the task.

C

[romanbednarek]

Provided Link: DIYcable.com Exodus LCR kit


> Hello,

> I am considering ordering parts for a center
> channel speaker and have the speaker built
> by someone who recommends the following:

> 1 DAYTON MTM-1.0BK 1.0 CU FT MTM CABINET
> 2 Adire Audi Extremis 6.8- 6.5" mid
> bass speakers
> 1 MOREL MDT-44 COMPACT SOFT DOME TWEETER
> 1 DAYTON XO2W-3.5K 2-WAY CROSSOVER 3,500 Hz
> 1 GOLD HIGH POWER TERMINAL RECTANGLE

> After talking to Parts Express, they
> questioned if this was a good configuration
> and suggested I post a message on Tech Talk.
> Does anybody have any opinions. I am a
> complete rookie at this stuff.
> Thank you,
> Bill Leeder

As others have pointed out, the odds of getting good results from a premade crossover are very slim. Even if I designed a crossover for you there are issues with the MTM design as a center channel unless you use an extremely low crossover point since the two woofers will cancel out off axis and give you dips in the midrange. Also the Extremis is a bit tricky to work with above 1kHz due to some peaks and dips. I managed to get some decent results with a crossover frequency of 2kHz but the crossover is a bit complex. The best way to build a center channel using those drivers is to add a midrange to the design in the center just below the tweeter.

There is already a very nice kit for this type of design available at DIYcable.com that uses dual Extremis 6.8s along with an Usher tweeter and a WR125 midrange. It is the Exodus Audio LCR kit and the link is below. I have a feeling that this kit will outperform any design that I might come up with using pure simulation tools because the driver set is very nice and it was designed using measurements. It may be a bit bigger that what you were looking for but I bet it sounds great.

So I think you can't go wrong with the Exodus audio LCR kit as a center channel and they have some other kits that might compliment it as well. If you still need further assistance let me know.

[davidyohn]

The Extremis is an amazing woofer. I use them and love them. If you need some crossover design assistance it's possible to get it directly from the manufacturer, send an email to their techincal support folks and outline your plan. They are always willing to help out a DIYer. <A HREF="mailto:techsupport@adireaudio.com">techsuppo rt@adireaudio.com</A>

> Hello,

> I am considering ordering parts for a center
> channel speaker and have the speaker built
> by someone who recommends the following:

> 1 DAYTON MTM-1.0BK 1.0 CU FT MTM CABINET
> 2 Adire Audi Extremis 6.8- 6.5" mid
> bass speakers
> 1 MOREL MDT-44 COMPACT SOFT DOME TWEETER
> 1 DAYTON XO2W-3.5K 2-WAY CROSSOVER 3,500 Hz
> 1 GOLD HIGH POWER TERMINAL RECTANGLE

> After talking to Parts Express, they
> questioned if this was a good configuration
> and suggested I post a message on Tech Talk.
> Does anybody have any opinions. I am a
> complete rookie at this stuff.
> Thank you,
> Bill Leeder