NEW MFW-15 amps (May 2010) *pics* - Page 13

Originally Posted by gonk

They are not and never were. At one time Mark Schifter spoke as if Emotiva was an internal brand developed by AV123 (similar to how he described his connection to Onix and their Reference speaker line), but after things went south with the LMC-1 and there was a business disagreement about a batch of bad sub amps the two companies publicly acknowledged that Emotiva was a separate company spun off from Jade Design in Nashville TN. There has been no business relationship between the two that I am aware of for probably three or four years.

Originally Posted by obie_fl

Doesn't sound like transformer hum more like a ground loop. My first thought would be to disconnect your cable connection and or satellite dish feeds. I'm talking the physical coax coming from the street or the dish outside.

Originally Posted by yadfgp

What about their latest MFW-15's? The v3 version. AV123 claims these are now complately built in the USA. There's been speculation I guess that these amps are produced by the same company that makes the amps for emotiva's subs. I guess if you think about it though, wouldn't that maybe be kind of silly? Seeing as how Emotiva is an amp building company?

Originally Posted by yadfgp

The v3's have very similar looking knobs on their amps that the Emotiva subs have on theirs! As seen in page 1 of this thread. Both companies introduced their new knobs at around the same time as well!

Hmm........ I suppose it is possible that AV123 buys their knobs from the same guys that Emotiva does.

Originally Posted by paligap

I posted this in the Emotiva Subs thread:

I currently have two MFW-15s (I know...) in a room of about 5000 cu. ft. I've gone through several amps and one driver, but I haven't had any problems in almost a year. In fact, they perform very well, but I'm a little worried about their long-term successful operation.

How much of a downgrade do you think two Ultra 12s would be?

Originally Posted by paligap

I'm sure the turbo kits are awesome, but to be honest, I don't think I need that much horsepower. My two stock MFWs blow me away as they are. There is also the matter of cost--what, $800 each?

I'm thinking that I could live with a little less horsepower, get a great deal with a good warranty, and maybe unload my MFWs. That's why I'm wondering how much of a downgrade it would be from 2 MFWs to 2 Ultra 12s.

Originally Posted by yadfgp

Well out of boredom, sitting here waiting for a response and thinking over what to do, I went back out and messed around to see if I could fix things at all.

I moved my new v3 sub over to where I am planning to put my other v3 sub that is coming in later this week. And using a different power cable, and a different rca cable, plugged into a different outlet, I plugged the rca into the LFE port and the hum is now gone! If I crank the gain all the way there is absolutely no hum period, using the LFE port.

So I dunno if it was 1 of the cables that was causing the hum, or maybe the outlet, but at least the hum is gone end of story.

The output is noticeably higher to. I ran some test scenes from a movie, and I can now get it as high as where I run my v2 MFW at so I can at least level match the output on both.

Whew! Just wanted to update on my findings in case anyone had read my last thread. Gonna mess around a bit more and see if I can find out what caused that damn hum and see if the output is as good as the v2 is. It's tough to tell which has the better SQ, to me they sound about the same so far.

UPDATE : After some messing around I guess the new sub is ok, gotta get the amp out though, can't be good having that loose bolt in there like that. The hum is non existent with the LFE output and I can get the same level of SPL with the v3 that I have with my v2. Going to bed for now.

Originally Posted by NicksHitachi

I believe that bolt might be the bolt holding the transformer to the back plate. If so the transformer is hanging loose in there resting on who knows what. This could definitely cause and/or contribute to a hum from em interference crossing over into the signal path depending upon what the transformer is resting against. I would recommend gently pulling the amp and not use it any more until you find out, shorting out due to wire stress from the transformer flopping around in there would be BAD. Also don't overtighten the bolt/nut, barely snug, or enough to keep it from moving on the plate, if you tighten it too much you could short out the windings.

Originally Posted by yadfgp

Well out of boredom, sitting here waiting for a response and thinking over what to do, I went back out and messed around to see if I could fix things at all.

I moved my new v3 sub over to where I am planning to put my other v3 sub that is coming in later this week. And using a different power cable, and a different rca cable, plugged into a different outlet, I plugged the rca into the LFE port and the hum is now gone! If I crank the gain all the way there is absolutely no hum period, using the LFE port.

So I dunno if it was 1 of the cables that was causing the hum, or maybe the outlet, but at least the hum is gone end of story.

Originally Posted by Bud84ro

Klipsch have they received your amp yet? Wondering if they found a problem yet

Originally Posted by KlipschHead281

I was promised a label back on 6/25 and have been so busy I haven't asked them why they haven't sent it to me yet.

I just wrote them asking for one now, they'll need to get it to me quick because I plan on being in a campground this Friday through Sunday taking it easy for the first time in a very long time. I'm going to start a fire and pretty much sit there and watch it, go fishing, then watch the fire, pet the dog a bit, watch the fire some more....

Originally Posted by Im2sexy

I think you left out the most important part, DRINK BEER in between watching the fire and fishing, and petting the dog.

Originally Posted by yadfgp

Thanks Nick, that's more or less what I concluded as well. I wasn't sure if that was the transformer due to my lack of knowledge on electronics but I figured it was. I haven't used the sub much just in case due to it's current state. Gonna buy a torx set today and then work on the amp tonight. Till then the subs remained off and unused till this gets taken care of. Thanks for your advice

1 thing I did notice in some of the pictures of the amp, is that it appears as though the transformer does have 4 screws going around it to hold it in place, and the bolt is just there in the middle for extra support or whatsoever so hopefully the transformer isn't just lose in there without that bolt holding it in there like it is supposed to.

Originally Posted by yadfgp

Well out of boredom, sitting here waiting for a response and thinking over what to do, I went back out and messed around to see if I could fix things at all.

I moved my new v3 sub over to where I am planning to put my other v3 sub that is coming in later this week. And using a different power cable, and a different rca cable, plugged into a different outlet, I plugged the rca into the LFE port and the hum is now gone! If I crank the gain all the way there is absolutely no hum period, using the LFE port.

So I dunno if it was 1 of the cables that was causing the hum, or maybe the outlet, but at least the hum is gone end of story.

The output is noticeably higher to. I ran some test scenes from a movie, and I can now get it as high as where I run my v2 MFW at so I can at least level match the output on both.

Whew! Just wanted to update on my findings in case anyone had read my last thread. Gonna mess around a bit more and see if I can find out what caused that damn hum and see if the output is as good as the v2 is. It's tough to tell which has the better SQ, to me they sound about the same so far.

UPDATE : After some messing around I guess the new sub is ok, gotta get the amp out though, can't be good having that loose bolt in there like that. The hum is non existent with the LFE output and I can get the same level of SPL with the v3 that I have with my v2. Going to bed for now.

Originally Posted by yadfgp

So played the same scene I'd been playing before with my v2 and this new v3, and I can match the output db wise for both subs, but my v2 definitely has more head room. The v2 I always leave at 11:30 or so for gain, and to reach that output level db wise, I need to have the v3 at around the 4 o'clock position! So the v2 is only like halfway around the gain knob, and the v3 is just a hair over 3/4 up.

Originally Posted by D.T.MIKE

Yadfgp two things, did you level match both subs prior to testing real world material and if so is there a gain in signal strength by running a splitter using the lt and rt line level in's instead of LFE in on the v3 amp?

Originally Posted by yadfgp

Well, I went ahead and tried level matching, with just the subs running and none of the other speakers, and DAMN!

Before when I had checked the levels, I had basically played the plow scene from The Crazies, cuz it's got a TON of bass and it just hits you hard and gets right to it and seems like a good scene to see how good your sub is.
So previously I had all my speakers running as I normally do, and would run 1 sub by itself and check the levels with my rat shack SL meter, and then make a note of what a good average DB was, then I would turn that subs volume all the way down, and then go do the other sub and just adjust levels on both subs till I got around the same DB reading on both subs. I had the meter positioned from the primary seating area which just happens to be the same distance to each sub, I actually measured.

I know not the most scientific and accurate way to do this, but in real life it should more or less kind of suffice.

Anyways, I had to really crank the v3 as I said before, to get the output in DB as the same as my v2.

I took my rat shack meter and put it within a foot of the v2. Left the gain at its normal, 11:30 position. I turned off my amps to all my speakers so just the v2 was outputting sound. Replayed the plow scene from The Crazies. The DB was reading around 115 DB!!! I was like WOW!

It's really kind of fun just to have your sub going so that you can actually see, and feel what that sucker's doing.

So I turned down the v2, and then go over to the v3, and put the meter about a foot away from that, and then turn the volume up on that, to around the 11:30 position, the same as the v2, I replay the plow scene, and HOLY BLEEP! I was hitting a tad bit lower than the v2, an average of around 112 or so. I then turn the gain up a tiny bit more and am able to achieve the same 115 or so that I was getting from the v2!

I now feel like a complete and total idiot because in reality the v3 does seem to perform just about the same as my v2.

I now realize the importance of level matching each sub without any other speakers going.

So I am also relieved that all is well. The v3 amp gets a thumbs up from me.

So I guess from here, my next step is to just level match them both up to be at the same DB level from a foot away. Even though when watching movies the volume may actually not seem as high on the v3, as it is on the v2. And then just leave it that way. Right?

Just seems weird to me that in a real world situation, watching movies, my v3 was so much quieter than the v2.

Can't wait till my other v3 gets here in a few days.


EDIT : Quick question, now that I think about it, when I was running each sub by itself, with the rat shack meter only a foot away from each sub, I was getting an average of 115 DB's at it's normal gain setting. And that's with the AVR receiver at it's normal gain setting that I would have it at if I were actually just watching this movie. I play my movies pretty loud. In my experience, when playing movies, I usually get peaks of around 105 DB's. Am I at a safe setting if I were to keep it this way? I can push the subs a lot harder, and my v2 at least has never bottomed out.

Originally Posted by yadfgp

Before when I had checked the levels, I had basically played the plow scene from The Crazies, cuz it's got a TON of bass and it just hits you hard and gets right to it and seems like a good scene to see how good your sub is.

Originally Posted by jehanzeb

Maybe I am reading this wrong so help me out.....
if you level match two subs, individually, for 80db, then don't you end up with 80db plus 80db when they are both playing at the same time ?

So, instead, you would set the phase first, as the DB level will fluctuate while setting the phase.

Then, level match the subs playing at the same time from your listening position.

No ?

Originally Posted by D.T.MIKE

I would set the phase first then sub volume one at a time with the other off. With both subs on if they are co-located you should see about a 6db gain or about 3db or so if the subs are spread out. You can then use your sub out trim level on your AVR to level match the subs to your speakers which will adjust both subs together and not mess with your previous level matching. Just one way of doing it. When I ran dual stacked subs used to set them up at 6db summed over center channel volume uncorrected with my rat meter.