Dave's 8" woofer + 104mm tweeter speaker build

[DaveFred]

Hello,

I am a little late in starting on my InDIYana 2023 build, I spent quite a bit of time testing drivers to see which ones would work best for what I wanted to do. For those who do not know, the Midwest Audio Club has an annual get together in Fort Wayne Indiana in April where one of the things they do is have a friendly theme speaker contest. This years is, Mix a =>8" driver to a tweeter <=104mm inna box <=1.5 cubic feet. My entry will be a Wavecor WF223BD01 8.75" woofer, Seas Prestige 27TBCD/GB-DXT tweeter and Dayton 10" passive radiator in about a 1.3 cubic foot box, about 21" tall, 15" deep and 12" wide.

Enclosure front/back/top/bottom will a pseudo translam with me making translam panels then butt joining them with a lock rebate joint. The baffle itself will start out as a 3" thick panel, but more than half by weight will be removed from it by the time the enclosure is done. Top/bottom/back will be ~1.125" thick panels with the sides being regular 3/4" baltic birch panels with ~1/4" cherry thick veneer applied to them.

BTW, I am soliciting name suggestions for this build, so please suggest some!

 

[DaveFred]

... more pics ...

 

[WhiteDragon]

Interesting build with the stacked ply panel construction.
look forward to seeing more.

Have designed 8" + tweet system myself, cant help
to admire the design concept.

Also thinking of doing passive radiator project.

Seeing a real world project using both concepts
is pretty cool.

Far as names maybe " Against the Grain "
to acknowledge the stacked ply.

Or simply just " Stacker"

I dont always like titles for product names.
Just letters and numbers.
The longer and more confusing the better.

" against the grain as acronym =AG
then use the driver sizes for number.
8" and 104mm

So = AG8104

or Model AG8104

or Stacked Ply so...

SP8104

SP-8-104

etc etc..

 

[A4eaudio]

BTW, I am soliciting name suggestions for this build, so please suggest some!

Prestigious Sea Waves

 

[adason]

Don'tFret bookshelf

 

[system7]

Since the theme is "Tweeter Yoga", Prestigious Sea Waves" woks for me! Very Tai Chi!

Looks an OK woofer, but surely made for reflex?

With a DXT tweeter, it might flow like water. Breakup is a bit horrid though.

I wonder if this sort of modified Harbeth M30.2 XD idea might provide a unique selling point? Forget the cracked bell screw on panel here. But the recessed woofer can make crossovers easier with negative polarity on the tweet. I always suspect Harbeth use BW3, of the 90 degree phase at crossover providing better power response at crossover.

But your project. Hope you win! 🙂

 

[DaveFred]

Looks an OK woofer, but surely made for reflex?

@system7 Not sure what you are saying here, are you suggesting using it with a PR is a bad idea?

 

[Signal lost]

How about "Dust in the wind" for all the sawdust you are making.

 

[Drummer2005]

8.75+ non guide dome, I say name them Fat Bottomed Girls! They could make your rockin' world go round. Glenn.

 

[tktran303]

Dave, from your small tweeter roundover / bevel study, what did you conclude? Are you planning to use any in this speaker?

 

[wolf_teeth]

Looking forward to it, Dave! I have not even cut wood yet, but I built for Bare Minimum in 2 weeks.

I do have one clarification though. While the crew at MAC do usually help out if asked, and Bill's photos additionally go to them for archival (much appreciated for all the help and support to those involved, by the way); InDIYana is not really an MAC sanctioned or directed event. I myself (with help) iron out most of the planning and details. Iowa and Chicago events however tend to be MAC driven events.

To those that have entered, I look forward to the challenge. Just FYI, theme entry is closed. This truly is a labor of love.

 

[Richard Ellis]

According to my simulations, cramming that Wavecor "nine inch" into a sub-sized sealed enclosure is a waste...its performance in a sealed enclosure doesn't work. Passive radiators as substitutes for simple ports really has fallen out of favor.
For a superb performance, I got a simple ported enclosure tweaked to 65 Liters worth, a tuned fb of 31.5 hertz for a response of -3.1 Db @ 28.78 hertz.

-----------------------------------------------------------------------------------------------------------------------------------------------------------Rick...

 

[A4eaudio]

According to my simulations a sealed enclosure is very different than a passive radiator. Ported vs PR, not much difference. (This is just the transfer function, but it is the same for group delay, cone excursion, max SPL, impedance, impedance phase, etc.)

 

[mordikai]

Dave this is awesome can't wait to see the final result. Any idea where youre planning to cross? Also, how does the dxt not qualify as having a waveguide?

 

[system7]

I have checked the rules of the competition, and the Seas DXT and Morel CAT 378 are both eligible despite being shallow waveguides:

wolf_teeth: I do foresee there being some CAT378, Seas 27 DXT, and Wavecor TW030WA14. Maybe some others exist....

It is well-known that such tweeters avoid cabinet edge diffraction problems, albeit at the cost of narrower dispersion.

The rules on ABRs might be open to interpretation. Some might call that a 3-way. Cetainly reflex is cheaper.

To answer the question, Qts= 0.39 and Vas= 45L says reflex 1.5 cubic feet as close to the optimum reflex mark.

 

[wolf_teeth]

They are sold with the waveguide, and are smaller than 4" square or 4.125" diameter.
This is why they apply. There is an SB unit too. No homemade guides.

I am using a PR in mine too.

 

[ernperkins]

Are you going to use XMachina for crossover development?

 

[wolf_teeth]

Me, no.

 

[DaveFred]

This week I cut the driver openings, doesn't sound like much when you say it, but was a bit of work...

 

[DaveFred]

... moar pics ..