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NEW MFW-15 amps (May 2010) *pics* - Page 6

post #151 of 2590
Quote:
Originally Posted by craigsub View Post

From recent reports, it appears the MFW-15 now has added more than just failing amps to its detriment: It also looks as if the response curve is considerably weaker than the original.

Your ratings have had widespread appeal, I think because of their detail and easy to understand ratings. Rather then noting what the latest version looks or appears like, second hand, why don't you test the new subs and publish the results. Not only would that lay to rest any speculation but it would provide a current comparison with the subs you will be selling in the near future.
post #152 of 2590
Quote:
Originally Posted by NicksHitachi View Post

I put something together the data is there for some of you more estute to manipulate.

I DO see the steep roll off after 30Hz, although still >100db well below 20 with the AVR set to -30. Looks like the V3 dips a little in the under 30, and is a little stronger in the 60-80 range. I do want to stress that I was not pushing either amp to their maximum output, but I never do anyways. This is where I would have them integrated for normal theater listening and normally run the AVR at -18 for movies. I backed off the volume since I have fried too many voice coils with test tones and reference output. This set of test tones takes about 15-20 minutes and (in my opinion) thats a lot of demand on any driver.

I did notice while comparing the amplifiers that the capacitors on the V3 are 2200uF and the V2 had 1500, and that the inductor was quite different with the V3 looking nicer and more substantial.

I did not have time to do much demo but I'll do that soon and chime in.

Best Positive- This amp runs COLD even after 20 minutes of test tones it was cold, not cool, or warm, but cold to the touch.

I would recommend anyone replacing their amp to invest in some weather stripping as my new V3 did not have the sealing tape around the amp plate. I also noticed the transformer was a little loose on the bolt, but I left it as it was, I remember reading somewhere you can damage it if you overtighten a toroidal, short out the wires or something.

More to come!

Cheers!

The only thing I could match was the amp runs very cool, I have to agree, no matter how hard you push it, it doesn't even get warm, (of course, mine doesn't produce as much power either). So, I got amplifier dud number 7, great.

Thanks for posting your findings NicksHitachi!
post #153 of 2590
Sorry to go slightly O.T. but this is amp related.

I've had a B stock MFW for about 5 weeks now. Mine has zero hum (my house was wired in '57), and has performed very well. But my amp stays warm/hot all the time. Even if i turn the switch to off for a day, the amp is still warm to the touch. I was getting ready to get a remote controlled power strip to completely cut power to the amp when not in use, but then I read where some of the amps were blowing when powered up.

For those who have blown multiple amps, are you leaving the amp in standby, powering it off with it's power switch, or completely cutting the power to the unit when it's not in use? And the same question for those of you who've had NO issues.
post #154 of 2590
Quote:
Originally Posted by MarauderYak View Post

Sorry to go slightly O.T. but this is amp related.

I've had a B stock MFW for about 5 weeks now. Mine has zero hum (my house was wired in '57), and has performed very well. But my amp stays warm/hot all the time. Even if i turn the switch to off for a day, the amp is still warm to the touch. I was getting ready to get a remote controlled power strip to completely cut power to the amp when not in use, but then I read where some of the amps were blowing when powered up.

For those who have blown multiple amps, are you leaving the amp in standby, powering it off with it's power switch, or completely cutting the power to the unit when it's not in use? And the same question for those of you who've had NO issues.

The heat is "normal" I wouldn't be surprised if the amp failures are not partially attributable to the heat the components of the amp are subjected to. I read somewhere that for every 10 degrees rise in temp was like 20% loss in lifespan of electrical components(or something like that), someone should take a temperature reading on those babies and see just how hot they are getting. Mine is VERY hot to the touch even in standby.

To address your question on powering off, I personally would not, mine make thumps, bumps, or ticks when I power them on from an off state. Because of this behavior I personally would not.

I've actually contemplated blocking off the back plate and moving the V2 amps outboard with wire mesh cages which would solve humm and heat. I may strongly consider this more after seeing how the V3 amps pan out.
post #155 of 2590
Quote:
Originally Posted by MarauderYak View Post

Sorry to go slightly O.T. but this is amp related.

I've had a B stock MFW for about 5 weeks now. Mine has zero hum (my house was wired in '57), and has performed very well. But my amp stays warm/hot all the time. Even if i turn the switch to off for a day, the amp is still warm to the touch. I was getting ready to get a remote controlled power strip to completely cut power to the amp when not in use, but then I read where some of the amps were blowing when powered up.

For those who have blown multiple amps, are you leaving the amp in standby, powering it off with it's power switch, or completely cutting the power to the unit when it's not in use? And the same question for those of you who've had NO issues.

My v2 amps (from Jul '09 forward) had issues with the auto shut off, ran very warm and every one that blew, blew on startup. Either way, I still power them on with a switched outlet to conserve.

I have no idea how long they will last, I have one v2 amp that is still running as designed and 6 that didn't.

Good luck.
post #156 of 2590
Quote:
Originally Posted by NicksHitachi View Post

The heat is "normal" I wouldn't be surprised if the amp failures are not partially attributable to the heat the components of the amp are subjected to. I read somewhere that for every 10 degrees rise in temp was like 20% loss in lifespan of electrical components(or something like that), someone should take a temperature reading on those babies and see just how hot they are getting. Mine is VERY hot to the touch even in standby.

To address your question on powering off, I personally would not, mine make thumps, bumps, or ticks when I power them on from an off state. Because of this behavior I personally would not.

I've actually contemplated blocking off the back plate and moving the V2 amps outboard with wire mesh cages which would solve humm and heat. I may strongly consider this more after seeing how the V3 amps pan out.

I'm very interested in hearing your impressions on sound quality for the v3 amp. I'm going to call Kyle today and let him know I'm going to do the same thing you did tonight, if yours were essentially equal I should be able to post the exact difference at the same settings even if we don't have the same AVR.
post #157 of 2590
Quote:
Originally Posted by David James View Post

Your ratings have had widespread appeal, I think because of their detail and easy to understand ratings. Rather then noting what the latest version looks or appears like, second hand, why don't you test the new subs and publish the results. Not only would that lay to rest any speculation but it would provide a current comparison with the subs you will be selling in the near future.

He's now bringing out his own products. I don't think he wants to open the can of worms of reviewing or facilitating the review of "competitors" subs.
post #158 of 2590
Quote:
Originally Posted by KlipschHead281 View Post

My v2 amps (from Jul '09 forward) had issues with the auto shut off, ran very warm and every one that blew, blew on startup. Either way, I still power them on with a switched outlet to conserve.

I have no idea how long they will last, I have one v2 amp that is still running as designed and 6 that didn't.

Good luck.

I certainly don't like wasting power, or having my amp hot/warm all the time, but your results have me hesitant to completely kill the power supply. I'm going to see if any others have similar results to report.

Maybe finding a way to cool the amp without killing the power will help prevent the failures.
post #159 of 2590
Quote:
Originally Posted by MarauderYak View Post

I certainly don't like wasting power, or having my amp hot/warm all the time, but your results have me hesitant to completely kill the power supply. I'm going to see if any others have similar results to report.

Maybe finding a way to cool the amp without killing the power will help prevent the failures.

When I had my duals I used to shut them off from a switchable power strip. Left both sub amp switches in auto on all the time. During power up no noise, when the subs came on after signal detection no noise. When I shutoff the power strip with the sub amp lights still green I got a very, very slight burble type of noise this is the way I always turned them off. When they were powered off with the sub amp lights red a loud type of noise. Did this because to me the amps were just too warm for my comfort. This is of course how my amps behaved both were v2 models. Like you never had any problems with mine other than the heat while in standby mode. Hope this helps.
post #160 of 2590
Quote:
Originally Posted by MarauderYak View Post

Sorry to go slightly O.T. but this is amp related.

I've had a B stock MFW for about 5 weeks now. Mine has zero hum (my house was wired in '57), and has performed very well. But my amp stays warm/hot all the time. Even if i turn the switch to off for a day, the amp is still warm to the touch. I was getting ready to get a remote controlled power strip to completely cut power to the amp when not in use, but then I read where some of the amps were blowing when powered up.

For those who have blown multiple amps, are you leaving the amp in standby, powering it off with it's power switch, or completely cutting the power to the unit when it's not in use? And the same question for those of you who've had NO issues.

There is basically no difference in power consumption leaving them on or in auto mode. Mine are V2 and I've left both in auto mode since August with no issues.
post #161 of 2590
I have 3 of the older MFW's and have no issues with amps or anything else. I'm home all the time so my system is on for 14 to 16 hours per day what with music, tv, or moves. amps are doing just fine.

Bill
post #162 of 2590
It's good to see people have good experience with theirs and even though my 2nd MFW has been an issue MFW # 1 has been great. I can't use auto shutoff but otherwise it has been fine and sounds fantastic.
post #163 of 2590
Ran some more tests by turning the gain knob on the sub.
And so far the amp and driver look fine to me.
The amp did run cool for the entire 30 minutes I ran the tests.
Test tones were mostly, 40HZ, 30HZ and 20HZ.
No thumping or any other strange noises either from the cabinet or the driver surround.
This is at 31HZ (gain knob on mfw at 2 'o clock, AVR Sub level at +8, no other speakers connected):
post #164 of 2590
I have use an X10 module to turn off my MFW-15. It makes a thunking noise turning off which none of my other subs do/did but I don't want to pay my electric company $22-24 dollars a year to use my sub as a space heater (yes this is what it would cost at 11.5 cents per/KWH). I have had the MFW-15 since January I swapped the first amp because it has transformer hum the second is much better. No problems so far caused by my hard powering off (transformer hum was there from the get go). I don't think you will get good data one way or the other. I'd just pick your bias/poison on whether to turn off or not.
post #165 of 2590
Quote:
Originally Posted by jehanzeb View Post

Ran some more tests by turning the gain knob on the sub.
And so far the amp and driver look fine to me.
The amp did run cool for the entire 30 minutes I ran the tests.
Test tones were mostly, 40HZ, 30HZ and 20HZ.
No thumping or any other strange noises either from the cabinet or the driver surround.
This is at 31HZ (gain knob on mfw at 2 'o clock, AVR Sub level at +8, no other speakers connected):

You're running much hotter than I would at +8 on the AVR, for my v2 MFW I run at -4 in the AVR which nets 75db on the meter at the listening position. What does the meter read using the setup test tone in the AVR for the subwoofer when running this way? Typically people set it for between 70 and 80db.

I'm not saying you're running it wrong, it may need this much to get to 75db on the meter at the listening position.
post #166 of 2590
Quote:
Originally Posted by jehanzeb View Post

Ran some more tests by turning the gain knob on the sub.
And so far the amp and driver look fine to me.
The amp did run cool for the entire 30 minutes I ran the tests.
Test tones were mostly, 40HZ, 30HZ and 20HZ.
No thumping or any other strange noises either from the cabinet or the driver surround.
This is at 31HZ (gain knob on mfw at 2 'o clock, AVR Sub level at +8, no other speakers connected):

Whats your volume setting on your AVR? More importantly what are you reading at 40Hz? 5-7db hotter?
post #167 of 2590
Thread Starter 
+8 on the AVR!!!?? Holy Sh*t! I run 3 MFW's -7 from the AVR and around 10-11 o'clock on the v2 amp subs and I'm at around 80db where I sit.
post #168 of 2590
Quote:
Originally Posted by MarauderYak View Post

Sorry to go slightly O.T. but this is amp related.

For those who have blown multiple amps, are you leaving the amp in standby, powering it off with it's power switch, or completely cutting the power to the unit when it's not in use? And the same question for those of you who've had NO issues.

My Feb 2010-purchased B-stock MFW w/ v2 amp is kept in the AUTO mode, no burps when it powers on to green light (that I can hear), or on power off to red light (though I'm usually out of the room by that time anyways). It's plugged into it's own Panamax M5410 Pro, but will be using a Panamax M2Sub as soon as I take 2 minutes to do so to free up some floor space. I have no idea if the v2 amp is even warm in standby, but will check later tonight.

So far, my v2 amp and MFW have worked just fine since it was delivered , and have only experienced a few moments where it was a bit overdriven by some very challenging LFE passages at higher-than-normal-listening volumes.

Sorry to hear about the inconsistent v3 amp performance. If anything, maybe another reason to consider the Turbo upgrade when it's available. That, or part out your crippled MFW, then chop up the cabinet for firewood when the temps start dropping this fall...

If I knew I could sell my MFW for a decent price, I'd probably just buy a PB13-Ultra and be done with sub upgrades.

Ah, just another tattered page in the continuing MFW novella...too bad, since I have seem to have a pretty darn good working one.
post #169 of 2590
Quote:
Originally Posted by KlipschHead281 View Post

You're running much hotter than I would at +8 on the AVR, for my v2 MFW I run at -4 in the AVR which nets 75db on the meter at the listening position.

Right, I only did this for testing. AVR is usually at +1 or less.

Quote:
Originally Posted by KlipschHead281 View Post

What does the meter read using the setup test tone in the AVR for the subwoofer when running this way? Typically people set it for between 70 and 80db.

I believe it is 75 but I'll check it again.
post #170 of 2590
Quote:
Originally Posted by NicksHitachi View Post

More importantly what are you reading at 40Hz? 5-7db hotter?

More like 3db I think but I will write it down for reference.
post #171 of 2590
Quote:
Originally Posted by crOwcaine View Post

+8 on the AVR!!!?? Holy Sh*t! I run 3 MFW's -7 from the AVR and around 10-11 o'clock on the v2 amp subs and I'm at around 80db where I sit.

Right, this was to test max output only. Not for normal listening.
post #172 of 2590
Quote:
Originally Posted by mak99 View Post

If I knew I could sell my MFW for a decent price, I'd probably just buy a PB13-Ultra and be done with sub upgrades.

Ah, just another tattered page in the continuing MFW novella...too bad, since I have seem to have a pretty darn good working one.


If everybody in this thread who was not happy had purchased an SVS, Hsu, Epik, or what have you, no one would have had any problems to begin with and this thread would not exist. You know, when I was 15 my friend back in California got himself scammed by the white van. I didn't know about it either and if it were me, I would have gotten ripped off. I was lucky it was him and not me, but it was a valuable lesson learned for both of us.
post #173 of 2590
Quote:
Originally Posted by Stereodude View Post

He's now bringing out his own products. I don't think he wants to open the can of worms of reviewing or facilitating the review of "competitors" subs.

I was just thinking posting actual test results would be better then posting 2nd hand information. But you're right, he has subs to sell.
post #174 of 2590
Quote:
Originally Posted by Faceless Rebel View Post

If everybody in this thread who was not happy had purchased an SVS, Hsu, Epik, or what have you, no one would have had any problems to begin with and this thread would not exist. You know, when I was 15 my friend back in California got himself scammed by the white van. I didn't know about it either and if it were me, I would have gotten ripped off. I was lucky it was him and not me, but it was a valuable lesson learned for both of us.

Easier said then done. In the beginning "this" sub out performed "those" subs and many purchased "this" sub before they noticed the white van leaving the parking lot.
post #175 of 2590
Quote:
Originally Posted by craigsub View Post




I adjusted my graph units to be similar with what was used here. The graphs are similar to my eyes15-20db roll off under 20, both have the ~30 dip. The V2/V3 do have some midrange swell not on the old graph though.




Also a couple afterthoughts:
  • Check your phase with the new amps carefully. In other words if the V2s worked great at 180 that doesnt mean the new amps will. They must be set all over again from scratch.
  • Some of the roll off seen in my graph approaching 80Hz might be the AVR crossing over since i set my crossover to 80Hz. I should have set it to like 200Hz or something to rule it out.
  • Still listening for final verdict on this one.

LL
post #176 of 2590
Nick, you got that response "in-room"? I believe Craig's measurements were ground plane. Interesting.
post #177 of 2590
Quote:
Originally Posted by cschang View Post

Nick, you got that response "in-room"? I believe Craig's measurements were ground plane. Interesting.

Yeah, just put the SPL meter about 10-12" from the port laid on the floor.

KH- check your phase, I recall you saying you couldn't hear the new amp when it was playing with the V2, maybe they are out of phase?

Last night I was playing with integrating mine together and was getting poor response. I had transposed the phase setting off my old V2 amp to the new V3(wrong I know). Turns out they were out of phase horribly, reset the phase on the new V3 and netted 10db increase with the two phase matched. I know this is not earth shattering news, and its fundamental when integrating two subs, but seeing the cancellation of two out of phase warranted at least a mention.
post #178 of 2590
NicksHitachi,

I set mine up in a 2 channel rig so the AVR would be completely removed from the equation. Straight from Mac Pro, to mixer to 2 channel amp using the following.

Last night I could only perform listening tests since I worked until midnight.

Running the same song on each config the only adjustments I could make were the volume on the Mac Pro, gain settings on the mixer and gain settings on the plate amp.

V2 plate amp set to 11am, Mac Pro volume set to 50% and mixer channel gain set to 75%, main volume on mixer at 40% netted 100db.

V3 gain set 100% netted 88db, another unscientific test I know but there it is. I am copying my test tones to my Mac Pro and running better tests when I have some time.

I'm in the JP Morgan Chase (I hate the company, but like the event ) corporate challenge tomorrow and Friday going to a Cubs game so not going to have time until this weekend.

I have no doubt the V3 that NicksHitachi got works as designed, unfortunately it looks like the one I got and a few others received doesn't. I am going to prove it as best as I can however I think the basic test conducted so far proves without a doubt my V3 amp is weak compared to the V2.

Quote:


Originally Posted by NicksHitachi - KH- check your phase, I recall you saying you couldn't hear the new amp when it was playing with the V2, maybe they are out of phase?

My ears are very sensitive to phase, this was the first thing I checked for, Kyle mentioned it as well. One thing very noticable between the two is how the driver is pushed, my V3 at max and being pushed hard doesn't move the driver much, the V2 is very capable of blowing the driver out of the box if pushed too hard.
post #179 of 2590
KH- when you pull out the V3 amp, look to see if there was a "tested OK" sticker on the back side of the amp plate. I saw mine somewhere close to the transformer I think. Not that it means anything, just curious.
post #180 of 2590
Quote:
Originally Posted by NicksHitachi View Post

KH- when you pull out the V3 amp, look to see if there was a "tested OK" sticker on the back side of the amp plate. I saw mine somewhere close to the transformer I think. Not that it means anything, just curious.

If memory serves, mine does not have this sticker but I'll verify tonight.
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