OK I will add HQ large pics of the 4029 for refereance and make it easy for people to see whats what without taking apart thier own speakers. And add all I know about them for this post.
Also this shows the foam rot area on the midrange cover that must be looked at and fixed if need be according to user Videolady201. Again thanks to her/him for the info and graphs and let us know...
Also Videolady201 findings have collaborated with the 4029 being 6ohm driver; the 4029 is 6ohms and not 4. Videolady201 has measured the impedance difference between the 4029 and 4024; the 4029 do have a valley in the 1Khz range compared to the 4024, this is why they use different crossovers (of course
). I think a lot of the 4029 stickers that say 6 ohms must have fallen off over the last 30 years...
My Mach One 4029 Pics external and internal, original owner of 30 years. taken just weeks ago (April 2010).
Midrange is in the top sealed off from the woofer. The woofer is in a very small cabinet! This midrange today would cost a lot. Its made up of many solid and thick plastic parts. And its just huge for a mid-range horn. More in-line with older JBLs types.
Critical, according to Videolady201 the felt/foam seal here must be intact as its the only thing that presses the midrange plate down against the magnet. If its worn away distortion can/will occur. Could be why some did not like the Mach ones!!!
Large woofer and decent magnet. The vent was stuffed with fiberglass 30 years ago, by design. Well at age 16 I had better ideas I pulled off the cloth filter and removed the fiberglass so it could vent the woofer better. There is also an inner filter as well so its not exposed. I glued the outer filter back on but it most have fallen off. I won't use fiberglass when I finish restoring them but something more solid. Anyways after all these years no fiber glass has been sucked into the inner filter (that I know of). The Vc was large 2.25" or 2.5" and took some serious abuse... like pumping a few hundred watts into them of bass program material and you could smell them heating up but they did not give.:thmbsp:
BTW: This trick does work, as logic would lead you to believe and as I felt with my hand the woofer ran cooler removing the fiberglass, I heard no sound difference, why they plugged it I don't know. But it made the vent useless.
BTW.
To aid in removal of the 4029 bezel around the woofer the 4024s don't have use a hair dryer and carefully heat it up and work it off. Mine had clips but was also glued?.
On to the bullet tweeter and standard but heavy duty liquid cooled 1" dome, with a decent magnet. The midrange did not have a high cut off so the horn tweeter came in with a 2nd order Xover to fill in the highs and did so nicely. It might be a horn, but it did not have that fatiguing etchy highs of some metal domes. the highs as You can see by the graphs were nicely done.
Compared to a Vifa 1" soft dome used in many, speakers.
And the cross-over the resistors are 1ohm and 2ohms. The lower inductor is 1.0mH, the top 2.7mH; all other values should be easy to see. The Lpads are 50 volt 8 ohm heavy duty types.