X-MTM and X-CS build

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Tyson

Re: X-MTM and X-CS build
« Reply #60 on: 17 Apr 2021, 12:00 am »
Thanks, I appreciate that.  One thing to clarify is that these are my first build.  You may have me confused with someone else or it took me so long to do it that you thought it was two different builds, which would be entirely understandable.  It was a lot to take on for a first timer, but the risks turned out to be well worth it.

Oh you are right, I am sorry!  I got you mixed up with johnsk2514. 

But that just makes your results even more impressive!  Nice work man.

JWCoffman

Re: X-MTM and X-CS build
« Reply #61 on: 17 Apr 2021, 12:42 am »
Oh you are right, I am sorry!  I got you mixed up with johnsk2514. 

But that just makes your results even more impressive!  Nice work man.
No worries, I can see how that would be confusing.  He popped into this thread quite a bit to provide tips along the way, especially when I was having trouble with the glue ups of the MTM cabinets, so I did learn quite a bit from his build and others.  In fact I have his MTM build along with a couple others from this forum bookmarked so I could quickly reference them if I had a question about something.  That, along with the videos from Danny and Peter, got me a long way.

JWCoffman

Re: X-MTM and X-CS build
« Reply #62 on: 19 Apr 2021, 11:44 pm »
Here's a followup/conclusion after 40+ hours of burn in.  Sorry, long post coming.
tl;dr: These are great.  I'm finding a little boominess at a specific frequency that I'm sure is a result of the room.

After adding sand to the bottom chamber these now weigh in at ~105lbs each :o.  They are on spikes, which are then on the little plate thingies that come with the spikes.  I then had to attach some small furniture sliders to those to get them to move.  It looks a little rinky dink, but seems to work well.  We do need to be able to slide them easily, so I think that might be the permanent solution.

As for sound, wow. I was a little worried that I might not notice a big difference with these.  Turns out that wasn't a problem at all.  Seriously, I know many others on this forum have had this same experience, but these feel like orders of magnitude better than our previous setup.  I can't imagine what the NX series must be like.  My wife's jaw dropped when she heard them the first time as well.

In the first couple hours there was plenty of clarity in the upper registers, but they were a little thin in the midrange and virtually non-existent in the bass.  I was in meetings from home most of the day while they played in the basement, and at some point at 5-10 hours in I started to notice some bass frequencies coming through the floor.  As I checked in to them throughout the day the lower registers started to fill in more and more.  I didn't really start listening to them critically until they had a full 24 hours in them at which point we basically spent all day in the basement listening to music and watching movies.

The bass is deeper and punchier than I anticipated.  While they may not dig to subwoofer levels, "Intergalactic" by Beastie Boys (bass tip from Cheap Audio Man) was not lacking in low end, nor were any of the other bass heavy tracks I played.  I turned off my sub when I started playing these and haven't missed it at all playing music.  It will still be useful for movies, however.

After about 30 hours, I started getting better imaging and soundstage out of them, but that may also have been a result of me playing with the positioning a little.  I found about 2' from the front walls with about 10-20deg of toe in worked in that room as it is right now (no treatments).  I can't bring them out any more than that due to a doorway on the right side and furniture on the left.  Vocalists started really locking in to the center at that point and I had to keep checking that I didn't have the center channel running.

Movies are just as impressive with a far better sense of clarity and location from voices, sounds and effects.  The first movie I played was Pixar's Soul, which was a great showcase for them.  I'm still running the original rears on this setup, so I know there is another level of immersion awaiting us along with getting two servo subs in the mix.

BTW, I'm running these from a Sony STR-ZA810ES AV receiver (good, not outstanding) that I picked up on an open box deal a couple years back and I'm using banana clips in the tube connectors for the time being until I can upgrade the speaker cables (currently, basic 14AWG zipcord style) for a more permanent tube connector setup.  There is still a lot of improvement potential with these, and they still sound amazing.

The only downside I'm hearing is some boom in the bass at a specific frequency which I'm certain this is a room effect.  I tried plugging the ports to see if that mitigated it, but that only helped a bit.  I'm not adept enough to know what that frequency is, but I ordered a UMIK this morning so I can do some measurements with REW to target the offending frequencies (and what I'm sure are some holes in the response I'm not hearing) and start the process of getting some room treatments dialed in.

Finally, huge thanks to Danny and everyone here.  I could not see myself paying retail for what speakers like these would go for, so without DIY communities like this we would have most likely missed out on this great experience.

Tyson

Re: X-MTM and X-CS build
« Reply #63 on: 20 Apr 2021, 03:45 am »
Hell yeah man, that's what it's all about!  Not only do you have a GREAT sounding pair of speakers, but you actually built them yourself.  That's way cooler than just buying a pair online or from an audio shop.  And you are right, you are going to hear more and more improvements as you get the room and the rest of your equipment dialed in.

mlundy57

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Re: X-MTM and X-CS build
« Reply #64 on: 20 Apr 2021, 05:02 am »
These may be Danny’s entry level kits but as you’ve found out, they are anything but entry level.

REW is going to be very useful but it will be even more helpful once you get a servo sub in the system. I’ve found the PEQ in the sub amp very useful in pulling down a bass peak.

I’ve found added bass extension from room gain can be boomy/bloated. My towers play down into the upper 20s in my living room even though they were designed to be -3 at 40Hz. While that may sound like a good thing, the sound quality of the additional bass extension is not as good as it is above 40 Hz. Adding a servo sub and crossing the towers to it at 40Hz got rid of the bloated bass. The sub is way better below 40Hz than the tower is.

jonsk2514

Re: X-MTM and X-CS build
« Reply #65 on: 20 Apr 2021, 11:43 am »
Congratulations on your success.   :thumb:

I got a chuckle from some of your comments about the X-MTMS.  I, too, was worried as to whether these would sound appreciably better than what I had, especially with all of the hype they have and the work I put into them.  It only took a few seconds of playing them to realize what I now have to listen to.  Soul was one of the first things that I played.  My wife’s initial reaction to them was more subtle; she didn’t tell me to turn them down, or worse yet, turn off the music I was playing.  Better yet she sat and listened, wanting more.  For her that was high praise, indeed.

It is interesting that they create boom in the room you are playing them in.  I am sure all who are following this thread will be interested in what you find out and your solution.

JWCoffman

Re: X-MTM and X-CS build
« Reply #66 on: 20 Apr 2021, 01:16 pm »
These may be Danny’s entry level kits but as you’ve found out, they are anything but entry level.

REW is going to be very useful but it will be even more helpful once you get a servo sub in the system. I’ve found the PEQ in the sub amp very useful in pulling down a bass peak.

I’ve found added bass extension from room gain can be boomy/bloated. My towers play down into the upper 20s in my living room even though they were designed to be -3 at 40Hz. While that may sound like a good thing, the sound quality of the additional bass extension is not as good as it is above 40 Hz. Adding a servo sub and crossing the towers to it at 40Hz got rid of the bloated bass. The sub is way better below 40Hz than the tower is.
That's interesting about yours playing down into the 20's, I feel like mine are going pretty darn low as well but I don't have an adept enough ear yet to know how low.  While I'm waiting for my UMIK I may play with the crossover point in the amp to see about taming the room boom.  That at least will help ID that particular issue.  I see bass traps in my future.

Hobbsmeerkat

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Re: X-MTM and X-CS build
« Reply #67 on: 20 Apr 2021, 02:07 pm »
I feel like its a combination of placement and room size/shape.
A narrow/long room will likely allow for deeper bass than a larger or wider room. At least thats how it's been in my experience.

JWCoffman

Re: X-MTM and X-CS build
« Reply #68 on: 20 Apr 2021, 05:14 pm »
I feel like its a combination of placement and room size/shape.
A narrow/long room will likely allow for deeper bass than a larger or wider room. At least thats how it's been in my experience.
I think you are on to something there.
At 18'x27', this room is certainly longer than it is wide.  It's also not a perfect rectangle as there is a nook in the back with a little mini kitchen that extends the room to 32' in that area.  I'm also stuck with the left channel closer to the wall than I would like (about a foot) until I can get a narrower media shelf solution.
I also wonder what effect the sliding closet doors behind the right channel are doing.  They are very basic, lightweight hollow doors hanging from a rail and I wouldn't be surprised if they have a mean resonance to them.

JWCoffman

Re: X-MTM and X-CS build
« Reply #69 on: 30 Apr 2021, 02:50 pm »
Updates after getting my UMIK, fixing some noise floor issues, and realizing the cable from my laptop to the amp was bad.  I have some amateurish measurements.

SPL at listening position:


Waterfall:


Additionally, I took a quick speaker measurement of one of the MTM's with a 4ms time gate, mic 1m away on axis with the tweeter.  BIG CAVEATS: I'm very new to acoustic measurements and I don't trust my testing methodology with this.  So feel free to criticize as you see fit.


There does seem to be a dip at 1500hz which I assume is at the crossover point.  I also took some room measurements of each speaker individually that also showed a similar dip in both with a short time gate.  However, the room response doesn't show a dip there, but rather around 1k.

So...
What am I looking at?  The big thing that jumps out is the room issues below 200hz, but there's also the weird dip around 500-1000.  These are playing well in to the 20's, but it ain't great.  Perhaps couple servo subs could really help tame these, which has been my plan all along.
Thoughts from the peanut gallery?

Tyson

Re: X-MTM and X-CS build
« Reply #70 on: 30 Apr 2021, 02:59 pm »
Those peaks are definitely room mode, I have them too.  Welcome to the world of box speakers :). Fighting that type of stuff is a big reason I went to OB speakers in my downstairs system. 

I still have box speakers in my upstairs system though, and since I use Roon as my source, I just use the digital EQ in Roon to knock down those peaks a bit. 

The other things you can do is get some bass traps and put them in the corners, and subs can also help. 

JWCoffman

Re: X-MTM and X-CS build
« Reply #71 on: 30 Apr 2021, 03:20 pm »
Those peaks are definitely room mode, I have them too.  Welcome to the world of box speakers :). Fighting that type of stuff is a big reason I went to OB speakers in my downstairs system. 

I still have box speakers in my upstairs system though, and since I use Roon as my source, I just use the digital EQ in Roon to knock down those peaks a bit. 

The other things you can do is get some bass traps and put them in the corners, and subs can also help. 
That's my primary takeaway too.  Funny thing is my wife is kind of excited to help me DIY some bass traps for the corners since she can sew some covers out of a mutually agreeable fabric.  The nice thing is we can do that for much cheaper and quicker than putting together a couple servo subs considering those are currently out of stock.  I still have my old 12" sub, but it sounds so terrible with these I can't stand to have it on.
I should also add that some of the FR response above 500hz could very likely be a result of upstream issues with cabling.  Right now I'm using whatever I can find around the house to connect my laptop to the amp, so I should not assume the original signal is flat and free from interference.