Now that the driver will produce over 9db more output at 30hz, its rated efficiency in the low bass is now 3 fold more that what it was! Meaning it only takes about 1/6 the power to drive to the same volume level as before. The driver has a xmax of 3mm. This is 3mm + and 3mm - for a total of 6mm or 1/4". Because the driver does not have any focus ring or pole plate shorting ring, etc., it has a large stray flux field. I have found that the driver, due to this stray flux will yield a total of 9mm, or just over 1/3" of linear travel before modulation occurs. After the mods on the bass driver in Tier 2, the driver is hitting peaks of just over 5mm at 100 watts but producing 3 times as much output!! Now when including the SPL in the lowest octave, to produce a maximum SPL at 30hz, the power handling has actually increased. Running them at 100 watts with the increased efficiency is way to loud and feels like it will tare the house down. So, they are still linear in output at 100 watts RMS. If that is a trade off, it is well worth it because of the performance difference. All and all I think they will do just find!!:yes:
I will back up this information in testing charts when I release the Tier 2 paper!
Modulation is a form of distortion. Most people don't realize how much distortion there is in the bass region (or maybe most do?). We are talking at high output (for that driver), but not pushing it past its xmax, total modulation plus harmonic distortion in the tens of percents. What does this mean. The Mach One can handle at least when the driver was newish over 100 watts RMS and still 'sound' clean.
Because of the nature of human hearing we can't hear distortion in the low bass region very good. Unless its harmonics are high frequency in nature. But that's usually not the case. Or if its modulation that is too high, modulation distortion has been shown to be easier to hear because its not harmonic in nature (its not related to the music, its a secondary type distortion more mechanical in nature; trying to keep things simple...)
Now comes the reality. How much power does it take to really blow the 4029 MachOne woofer, or push it into audible distortion with-en it's usable Fs range (45Hz-20Khz), how much can you use with it. Simple answer is over 100 watts, and its a big reason I respect them so much. I have seen plenty of drivers blow. My friend was into car audio and his PPI amp put out clean RMS power not matched by anything we can buy for the home at under $2000. This was almost 20 year ago. I have seen voice coils nearly start on fire!! From cheaper woofers that used plastic for the Vc.
Once I had a real job and my brother got into Hi-Fi we went through a lot of gear. The Mach Ones sat in storage and would come out for tests and to play with and use if I sold my then speakers to buy another, it would fill in. I had them hooked up to a 200wpc amp playing a Bass Mechanic CD and it was moving a lot, its did get a bit warm. But to my surprise it just kept playing. At frequencies above about 50Hz it could take as much as you threw at it and sounded clean, cleaner than the speakers it was compared to but a few, the JBL CF150 series, and the Bose 10.2 series II.
But the JBL was another 15" driver in a 'much' larger vented box (The horns sounded cleaner however versus its cone mid, and dome tweeter), the Bose was an 8" driver in a Acusticmas enclousure, this loads the driver on the front and back (it uses both for sound) and somehow, someway, it kept up. Well really because as in that ad I posted its 8" driver did not have to move much and could take 200wpc.
Now with respect to the Mach One woofer note I said 200 watts and Video-Lady says 100 watts. Well at 200 watts RMS (or a bit more) playing a pure 35Hz tone you will see a driver moving what looks like 1" (total) and producing nothing but mush. How much xmax you need is a function of the frequency. As the lower you go, the further the driver must move. This is why as is the MachOne driver back in the day was rated for 160 watts of music and you were told you could use 'any' home amp with them. This was written well before the CD, and it was expected Rock lovers would blast them loud. Why do you think they put them in such a small box. They could have made the box 3" deeper. But RS went for max SPL and power handling in the 50Hz and up range. The MachOne (4029) has a big edge-wound 4 layer voice coil that can take some power.
Woofer motion is least at resonance, in this case 65Hz, hmmm right in the middle of where most of the bass is for rock music... but this was over 30 years ago. Now we have much deeper bass coming from speakers that use a 5" driver. The CD/DVD have changed the habits of the studio they now put in much more deeper bass. This mod is needed, bad...
Others can measure the MachOne drivers and so forth. But I have owned a new pair for about 30 years. I have thrown all kinds of amps at them.
I have real world tested them for 3 decades (that's a lot of experience) and know for a 'fact how robust the driver is or is not'. It can take the power of a 150wpc amp played all day without blowing. My MachOnes have such a long history even I forget things... I now remember that for a few years I used them at my works Christmas Party. We have a large, very large room in the building. I had my MachOnes hooked up to my then Pioneer receiver rated for 150 wpc, but really put out 180 wpc as tested by stereo-review. It was hooked up to a ladies electronic piano-organ (she was a piano teacher). This keyboard of hers did have small speakers but of course they were too small for the room... my MachOnes took the output of a live musical instrument at times driven to full volume no problem, and sounded nice for 4 hours, and when she could make those woofer move.
Bottom line the MachOnes have plenty of reserve in the 50hz and up range, its time to move it down to sound better with todays music, and I really like the idea and will do it to mine. What this means is VideoLady is moving the resonance from 65Hz to probably ? say 45Hz, so now they can take more power in the lower notes, but a bit less at higher. As I said it has plenty of reserve to loss some in that range and it won't matter a bit.
All I can offer is the fact that I have been a Hi-Fi buff for over 3 decades. I have owned a brand new pair of MachOne 4029s for 30 years, and had them apart 30 years ago. I have put them through all kinds of tests with different amps, against other speakers, you name it. I have been a fan since I saw them 35 years ago. Saved my money for them and bought them. I am now a Computer Programmer. But since I was in first grade I started to draw and design things. The first thing I drew was an engine but I asked myself how does it work? (it was a simple pic with pistons and rod/crank...). I use to go to the library to read on how things worked. In 5th grade I would design whole cars including where I wanted the engine for best handling. However there was no math or hard science behind my drawings. I had stacks of paper with drawings. At my peak in the 4th - 6th grade some of my ideas latter turned out real. The teach wrote "he always has his nose in a book". My mind was very visual and free to imagine things I put on paper. For example I read everything I could on insulation and architecture. I designed a house with a double wall that had a sealed air tight gap in the walls, this air gap was heated or cooled using solar, and pipes deep into the ground... anyways I latter read of a real house with some of the same concepts. Just one example of many of my designs that latter were real. I stopped drawing in the 8th grade (why?) and went to school to become a Mechanical Engineer. One of the courses I had to take was on programming, back then there was no java. But anyways I found better things to do with my time. When I went back to school some years latter Computer Programming was it and I enjoyed it. I am a very technical person at nature. But have no where near the skill, training or experience VideoLady has with Hi-Fi and speakers
You can't blow them with normal program material, with normal music (not too bass heavy) just as that instruction page said years ago. The Horns are even better at handling power than the woofer. The woofer is just stiff, the stiffest speaker I have ever tried to push. If your speaker does not give a lot of resistance when you try to push it in, its not what it was 30 years ago. Bach then I had to take my hand with my fingers spread out and slowly push it in using a lot of strength. It moved what seems like just over an inch before hitting the back, when you let it go, it would take some time for it to come back to its resting position.
Why do I tell you this like its special? Because many times I was afraid of blowing my MachOnes over the last 30 years. When that lady was playing them at the party. When I hooked them up to a 1000rms (500 into 8 ohms? enough to move them all the way!!!) amp (I could start to smell the Vc heating up so I stopped after some minuets) and many other times, I feared the worse. Almost every speaker I have ever owned for a period of time has blown at least a tweeter. This is my only speaker that has never blown a driver.
This is just one of the reasons I respect them and am happy VideoLady is going to bring them up to date.
