• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Mach One 4024, 4024A, 4029 Information and Upgrades!

Thanks Sendust - did you cut the holes to expand the internal woofer volume too? I'll have to get a drill bit to do that task.
 
absolve2525 said:
Thanks Sendust - did you cut the holes to expand the internal woofer volume too? I'll have to get a drill bit to do that task.
Click to expand...

I used a 31/2 inch hole saw and made 3 holes but i think the idea is to open the space for more volume, im sure larger holes or smaller is not as much as an issue as the opening itself. Although it was not one of the mods from VL i lined the lower chamber with ice shield and used it on the back of the speaker magnets, also used some on the plastic horn to reduce vibration, i was very pleased with the result...
 
Just wondering , along with all the mods by VL, has anyone also added any internal bracing, as mentioned a way back up in the first few pages of this thread?

Just wondering..

Rob
Montreal, Canada
 
Had a thought about the step of cutting into the midrange section to add cabinet volume. Could another option be to design an open-top box stand of similar length and width of the speaker cabinet, maybe around 8" high - then cut an opening in the bottom of the speaker and somehow fit the speaker over the stand. You'll add the cabinet volume as well as get the speaker up off the floor. I would think you would need some carpentry skill to tie it all together and make it look decent. Just a crazy thought. :scratch2:
 
These speakers have to be on the floor, they are designed to be on the floor, raising them off the floor will give them an undesirable sound... see VideoLady's tests and graphs about this subject a dozen or so pages back...

Its pretty easy to open up the midrange enclosure , simply drill 3 or 4 holes that are 3 or 4 inches wide or cut out a 4x12 section...

all comes to the same result....

if you have the time try and read through the whole thread, its pretty interesting if your really into your Mach One's!

:)

Rob..
Montreal, Canada
 
Last edited:
Actually I have read through the whole thread - don't remember the part about them having to be on the floor though. I thought I remembered reading many times in other threads where people thought the sound improved when they were on stands. Mine are currently on the floor and sound great - but I was hoping to raise them at some point to see the difference.

robmorin said:
These speakers have to be on the floor, they are designed to be on the floor, raising them off the floor will give them an undesirable sound... see VideoLady's tests and graphs about this subject a dozen or so pages back...

Its pretty easy to open up the midrange enclosure , simply drill 3 or 4 holes that are 3 or 4 inches wide or cut out a 4x12 section...

all comes to the same result....

if you have the time try and read through the whole thread, its pretty interesting if your really into your Mach One's!

:)

Rob..
Montreal, Canada
Click to expand...
 
tiga said:
Actually I have read through the whole thread - don't remember the part about them having to be on the floor though. I thought I remembered reading many times in other threads where people thought the sound improved when they were on stands. Mine are currently on the floor and sound great - but I was hoping to raise them at some point to see the difference.
Click to expand...

Look at the tier 1 upgrade report from VL
 
Found it! Scrap my idea then!

Actually there are a few posts in this thread where people said they improve off the floor - see posts 181, 182, 198. That may of started the idea in my head of building stands.

sendust said:
Look at the tier 1 upgrade report from VL
Click to expand...
 
Honestly I think this really will vary with the room. I have hardwood floors (raised floor, no foundation) and they were causing too much reverb so I raised them using generic stands, roughly 6-7" and tilted back a couple degrees (maybe 5?). Big improvement, not boomy like when they were on the floor. Just try it and hear for yourself. Also, the biggest thing for me was space between each speaker and angling them in. Once I had this correct the imaging was amazing.
 
Dude! Get out of my head! Wow. I've been contemplating this ever since reading about drilling holes in the mid chamber. Only my idea was for experimentation rather than executing a tested design change. I figured knocking (4) 2-3" holes situated around the terminals, then building a couple boxes with similarly sized/spaced holes and using PVC to connect the boxes to the Mach's and test different volumes. I have spare cabs that are pretty beat-up but have no leaks, per se, so no harm no foul. This would reduce the risk of improper sealing (on my part) of the mid driver. In fact, if VL, or anyone else for that matter, would like some tests performed and would provide some basic volumes they have in mind I just might be able to carry that out. Only issue left, however, is a means to scientifically capture the results. I've been contemplating buying an RS level meter, which can be pipe into a computer running audio software, just not sure what steps to take. Help???
 
I'd love to hear even more thoughts on the sound of the speakers after Tier 1 modifications. I have a pair of 4029s that are refoamed but have original caps. After listening to ARs, Advents and KLHs, the Machs sound so clear and present for the first couple minutes. Then within 10-15 minutes more, I often swap them back out. I love the presence, but my objections are that they get a bit grating on me. In addition, the highs in particular seem to change a fair amount depending on where I listen (standing, sitting, crouching, to the side). Most speakers do this to some effect, but the Machs seem to do so a bit more.

I think the Tier 1 mods sound like they will cut down on the harshness a bit and improve bass response, but do they do anything to improve dispersion or is that the nature of the horn drivers and the low tweeter placement? Do the Tier 1 mods create a slight improvement or a rather large one? Any Klipsch or Altec comparisons done before and after? Looking forward to seeing the Tier 2 mods and their impacts.
 
Look at my holes...

I have attached a before and after shot of my holes to the mid section of my 4024a. Very easy mod. I used a 6 inch saw and a 2.5 inch saw since thats all I had on hand.
IMG00035-20100905-1652.jpg

IMG00040-20100905-1706.jpg
 
Last edited:
Very well done, nice and clean.....

That is more than sufficient....

Way to go... I also see you have those pesky wooden bracket like i do, not all of us have those...
 
I received a mid driver to replace my toasted unit... many thanks to Copa1934 for his generosity, so I'm ready to complete this project... but as always I have a couple questions!

My originals are 4024A models, the driver Copa sent is from a fluid cooled model... this being the first fluid cooled driver I've ever had apart I have a couple questions before reassembly: The groove in the magnet that the VC slips into is full of the black oily fluid... should I clean it out? The fluid doesn't seem to be contained by anything...normal? Since my other speaker is non-fluid cooled can I just wipe this fluid off and go with it dry?

On another thought, I measured the new caps and they are a bit off: the 14Uf measures 14.88 (I combined 3 caps) the 8.2Uf measures 8.53 ( 2 caps) and the 4Uf measures 4.25 (single)...
Will this make a noticeable difference in the sound? I also measured the old caps and they each measured over a bit as well, could be my meter I suppose.
 
Mach Mods

Buttercup said:
I received a mid driver to replace my toasted unit... many thanks to Copa1934 for his generosity, so I'm ready to complete this project... but as always I have a couple questions!

My originals are 4024A models, the driver Copa sent is from a fluid cooled model... this being the first fluid cooled driver I've ever had apart I have a couple questions before reassembly: The groove in the magnet that the VC slips into is full of the black oily fluid... should I clean it out? The fluid doesn't seem to be contained by anything...normal? Since my other speaker is non-fluid cooled can I just wipe this fluid off and go with it dry?

On another thought, I measured the new caps and they are a bit off: the 14Uf measures 14.88 (I combined 3 caps) the 8.2Uf measures 8.53 ( 2 caps) and the 4Uf measures 4.25 (single)...
Will this make a noticeable difference in the sound? I also measured the old caps and they each measured over a bit as well, could be my meter I suppose.
Click to expand...

Yes, use a paper towel and just soak the fluid from the magnet gap. Once it's out, wipe again with a dry one to clean up what's left. It would be better for the drivers to match. Your caps values are ok. Caps will measure different at different frequencies and yours are close enough.
 
I received my new caps today from MCM, i am excited... i will be assembling my 2 Mach One's this weekend. Probably Sunday a i have to do our annual tomato sauce tomorrow... :)

I went for the simple electrolyte version of 50 volts as per the Tier 1 requirements nothing too fancy. I am sure they will work fine.... Maybe not last another 20 years, but hey i figure my son can take over at that time and upgrade them again... :) I shall leave detailed instructions inside the cabinet in a baggy for safe keeping, with pics and a print out of VLs PDF file.
:)

I shall post back on Sunday after i completed everything...


Wish me luck..
 
videolady201 said:
Yes, use a paper towel and just soak the fluid from the magnet gap. Once it's out, wipe again with a dry one to clean up what's left. It would be better for the drivers to match. Your caps values are ok. Caps will measure different at different frequencies and yours are close enough.
Click to expand...

If it's better for the two drivers to match, should I wipe the fluid from the VC as well as the magnet?
 
Sorry about the fluid mix up. For some reason I thought the tweeters were the only drivers with the ferrofluid. Based on comments thus far sounds like it will all work out anyway. I'll have to pay closer attention to the driver models so I don't make that mistake again.

I do look forward to your thoughts after completing your upgrade, so far their has been nothing but positive comments. Can't wait to start on mine.
 
Copa1934 said:
Sorry about the fluid mix up. For some reason I thought the tweeters were the only drivers with the ferrofluid. Based on comments thus far sounds like it will all work out anyway. I'll have to pay closer attention to the driver models so I don't make that mistake again.

I do look forward to your thoughts after completing your upgrade, so far their has been nothing but positive comments. Can't wait to start on mine.
Click to expand...

No problem Copa... I'm just happy to have found a stock replacement. The drivers are identical except for the fluid so I can't see how wiping the fluid off could be a problem.
 
You must log in or register to reply here.
Back
Top Bottom