So here's what I'm thinking for the MAC-04. A 2.5-way, 6" W x 34.5" H x 14" D tower in a TMMMM format to keep the tweeter height right. I always like the idea of separate chambers for each driver when possible to minimize standing wave length and offer better bracing, so that's what I'm gonna do. Each chamber will be 5 x 8 x 13, which is nearly an exact golden ratio, not that it matters, but it's kinda cool. 1/2" MDF all around to keep the size/weight down, but maybe a 3/4" front baffle depending on how much screw grip I can get with a recessed woofer in 1/2" material.
This will give me 0.30 cu ft gross volume for each driver, which with a little added inductor resistance and a 2" x 7" port, should give me:
Fb = 60Hz
F3 = 54Hz
1dB bump at 75Hz
Xmax limited power handling isn't great with this alignment, but a little extra energy in the 50-100Hz region sounds good with a highish F3 to me. I may see how it sounds with a tuning frequency of 50Hz or even lower for a little better cone control. We'll also have to see how they sound beyond Xmax. Port velocity with a 2" ID is a non-issue well over Xmax.
Sensitivity should be right around 90dB with full baffle step comp, so that's baby tube amp territory. Not sure what tweeter I'm going to use yet, but I think I have an MCM Audio Select tweeter that would be a good cosmetic match. Otherwise, I'll see if the DX20 can meet up effectively with the MAC-04.
Measured TS params of my MAC-6, 10 grams added mass, open air:
Fs = 54.50 Hz
Re = 7.80 ohm[dc]
Le = 1054.70 uH
Qt = 0.45
Qes = 0.48
Qms = 6.43
Mms = 26.01 grams
Rms = 1.374073 kg/s
Cms = 0.327843 mm/N
Vas = 8.11 liters
Sd= 132.73 cm^2
Bl = 12.013517 Tm
ETA = 0.26 %
Lp(2.83V/1m) = 86.40 dB
Pretty much right on spec, except FS is notably higher (~48 on spec), but just a little manual break-in moved it down to 52 which makes me suspect with full break-in it'll hit spec admirably well. Very nice!
= Howard Stark: "This is the key to the future. I'm limited by the technology of my time, but one day you'll figure this out."
I got around to breaking in my MAC-04 pair yesterday. I break them in with 60 Hz via a variac and step down transformer. I adjust the variac to achieve ~xmax displacement and let them little buggers hum along for 4+ hours. I let the voice coils cool to ambient for a couple of hours then measure the T/S with my DAT's. I used 15 grams of added mass. Fs was within 1 Hz of each other and 2 Hz of published spec. Re, Qms, Qts, and Vas were all within a couple percent. Better tolerances than I've ever measured from the Dayton Reference Series drivers.
While I am quite excited, my kids were quite disappointed when I opened my package from JuleFidelity today.
I get that Soy Sauce is good, but their level of excitement was on the irrational side.
Of course, they probably thought the same thing about my excitement for my new pair of MAC-05s, as I think I'm quoting verbatim, "another pair of speakers that dad spends all of his money on."
As an aside, I'm actually mildly allergic to tobacco, so that's why I held off on acquiring Rivals until they started showing up on the secondary market.
When my quad of R176-CP-08's showed up from RAD and I opened the box I was hit in the face with the worst/strongest cigarette smoke smell. Like someone was in the box smoking. It took years for the smell to fade off the drivers' soft parts.
Comments
So here's what I'm thinking for the MAC-04. A 2.5-way, 6" W x 34.5" H x 14" D tower in a TMMMM format to keep the tweeter height right. I always like the idea of separate chambers for each driver when possible to minimize standing wave length and offer better bracing, so that's what I'm gonna do. Each chamber will be 5 x 8 x 13, which is nearly an exact golden ratio, not that it matters, but it's kinda cool. 1/2" MDF all around to keep the size/weight down, but maybe a 3/4" front baffle depending on how much screw grip I can get with a recessed woofer in 1/2" material.
This will give me 0.30 cu ft gross volume for each driver, which with a little added inductor resistance and a 2" x 7" port, should give me:
Fb = 60Hz
F3 = 54Hz
1dB bump at 75Hz
Xmax limited power handling isn't great with this alignment, but a little extra energy in the 50-100Hz region sounds good with a highish F3 to me. I may see how it sounds with a tuning frequency of 50Hz or even lower for a little better cone control. We'll also have to see how they sound beyond Xmax. Port velocity with a 2" ID is a non-issue well over Xmax.
Sensitivity should be right around 90dB with full baffle step comp, so that's baby tube amp territory. Not sure what tweeter I'm going to use yet, but I think I have an MCM Audio Select tweeter that would be a good cosmetic match. Otherwise, I'll see if the DX20 can meet up effectively with the MAC-04.
You're a mad man Dan! But I like it!
Cool idea. I thought about stacking cabinets in another project.
Not so sure Dan is stacking cabinets. Looks more like he is just partitioning the air space for each driver.
Would have to hear the midrange on the 5" but sealed sizes don't seem too hateful. Maybe use as a centerpiece/accent mid in a 3-way.
Agreed but it reminded me of that concept.
Ah ok.
Lol that'd be neat. A bunch of brick enclosures with 4" drivers in em all stacking to a tower.
Call it the Lego.
Should be starting on a TMWW using JF tweeter, 4" and dual 6-1/2" soon.
Brad is going to be doing a 2-way with the same tweeter and the 5".
shhhh, not so loud.
They’re waiting their turn today.
Measured TS params of my MAC-6, 10 grams added mass, open air:
Pretty much right on spec, except FS is notably higher (~48 on spec), but just a little manual break-in moved it down to 52 which makes me suspect with full break-in it'll hit spec admirably well. Very nice!
Even those not broken in params model quite well in unibox, and better than the docs suggest:
Someone is doing a good job of QC with those drivers.
For sure to that!
I got around to breaking in my MAC-04 pair yesterday. I break them in with 60 Hz via a variac and step down transformer. I adjust the variac to achieve ~xmax displacement and let them little buggers hum along for 4+ hours. I let the voice coils cool to ambient for a couple of hours then measure the T/S with my DAT's. I used 15 grams of added mass. Fs was within 1 Hz of each other and 2 Hz of published spec. Re, Qms, Qts, and Vas were all within a couple percent. Better tolerances than I've ever measured from the Dayton Reference Series drivers.
Hat's off MAC!
TMWW coming along. Ready for measurements.
Lookin good, JR! Were these "funnner" to construct than MT's alone?
Have to ask Brad
I am going to start another thread on the TMWW.
While I am quite excited, my kids were quite disappointed when I opened my package from JuleFidelity today.
I get that Soy Sauce is good, but their level of excitement was on the irrational side.
Of course, they probably thought the same thing about my excitement for my new pair of MAC-05s, as I think I'm quoting verbatim, "another pair of speakers that dad spends all of his money on."
Sorry, mostly all my boxes are recycled from the grocery store just across the street from me. There’s no use in spending more money on cardboard.
Bet your drivers smell better than anyone else's.
Better than RAD for sure!
Agreed.
As an aside, I'm actually mildly allergic to tobacco, so that's why I held off on acquiring Rivals until they started showing up on the secondary market.
I don't understand the connection here. Did I miss something?
InDIYana Event Website
Me too. Never ordered anything from RAD.
When my quad of R176-CP-08's showed up from RAD and I opened the box I was hit in the face with the worst/strongest cigarette smoke smell. Like someone was in the box smoking. It took years for the smell to fade off the drivers' soft parts.
Wow. I had no idea.
InDIYana Event Website