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Full Marty Advice

16K views 75 replies 16 participants last post by  Gary Mertz 
#1 ·
Greetings! I am hard at work on building my home theater in a redesigned basement room. I'm looking for a flat pack option for dual subs, particularly at the Full Marty. I'm looking for something that would fit the bill for about 60/40, maybe 70/30 HT/music and I'm interested in good tight punch from the subs. The room will end up being about 2500^ft on concrete slab.



Do you think I'm looking in the right direction for the Full Marty?
 
#3 ·
I should have also asked, what about the driver that would be best suited to my purpose? I would be pairing it with the NX6000D amp.
 
#4 ·
#10 ·
You do know that is an apples to grapefruit comparison right?
Not everyone wants chest thump AND not everyone wants to spend $750 for a driver..... the fact that you can..... yay you...


Juju
 
#7 ·
I don’t think any single sub is going to give you what you’re looking for. Small rooms just don’t work like that, especially on concrete. REW will tell you how many subs you need and where you need to put them. If you do your part with location and placement, um18 Marty’s are absolutely thunderous, and they work great off nx amps.
 
#8 ·
Its pretty hard to guess what people want, chest thump usually pretty standard sensation that individuals want but sometimes it depends on what they listen to or watch or how their room is laid out.


Typically CHEST THUMP is from a major boost in midbass, 30'ish hz and up. If you want that the UM18 won't give it to you. The UM18 will get you a flat response down very low, for a very low price in a medium sized box. If you want chest thump and don't care much about infrasonics you can use a PA 18" or 21" and have enough room to boos the midbass till your ears and your neighbors ears start to bleed. Normally you won't get low end with PA subs, or you can it just requires a lot of additional factors unless you buy a sub like the NSW6021, which 2.5x the price of a UM18.


I have both the NSW and UM18, both are great drivers and the NSW is obviously better as its a lower-priced iPal competitor but really I was super happy with the UM18's (I eventually supplemented them with a pair of 12" mag woofers).
 
#9 ·
I should have specified that I will eventually get dual subs without question, I just don't know if I'll have the budget to do both at the same time. I'm not concerned about the higher price for the NSW if it is indeed worth the price for a good tight bass response.



Back when I was keeping track of these things and generally speaking, a 21" driver was just a boom boom sub with poor control. I take it that the 6021 is able to provide a tight bass output?



They will be driven, I think by the Behringer NX6000D as I've heard some good things about it and has a good price on the GSG website.
 
#11 ·
I can't imagine anyone not wanting the chest slam that comes with a well tuned system both for music and for HT. Of course the price of admission goes up but sometimes you do get what you pay for.
 
#14 ·
Thank you all for the ongoing discussion, it is really helpful.



Can any of you explain in greater detail the differences you experienced between the UM18 and NSW? Certainly the 21 is going to push more air but movement of air doesn't necessarily mean it is clean and tight. I listen to some metal that has very fast punchy double bass and I'm looking for something that can keep up with that without turning the kicks into a jumble of rumbling. A more mainstream band for that would be Five Finger Death Punch. At the same time I enjoy some jazz/fusion that also requires a tighter sound for the bass drum as well as for the bass (instrument) itself. Think about Victor Wooten and his brother when they play with Bela Fleck. And of course movies with lots of things blowing up! Think about any Transformers movie.
 
#15 ·
I have a mini Marty um18 and can tell you first hand it won't give you any chest slam. I added 2 18" vbss subs and they give me tons of chest slam (placed near field).

If I were you I would build a 21" Devastator as it will give you the best of both worlds. That's what I should have built instead my Marty plus vbss subs...

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#16 ·
Very reasonable questions with difficult and subjective answers. I’ll give you a few things to think about and a few resources. First, to use the NSW’s full potential you’re going to want to feed it more sauce than an NX amp can deliver. Nx will work fine but you’ll be leaving some potential on the table. Many here use a clone amp or high-end pro amps like a speaker power amp. Second, check out this vid on “chest slam”



Finally, there’s a great chart on GSG comparing various boxes and drivers:

https://shop.gsgad.com/pages/performance-comparison-table

If money is no object then some NSW drivers driven by speaker power amps would be badass. Heck, if money’s not an issue so would a bunch of JTR subs and speakers. But if it is a consideration I’d bet a pair of WELL PLACED GSG devastators with 21” lavoce drivers driven with an NX6000d would fit the bill very nicely.
 
#17 ·
Tight and clean aren’t characteristics of a sub. Neither is boomy’ness.

What you are describing are typical poor box design OR poor room acoustics. When a sub reaches lower octaves they typically excite a room mode and you get a sudden boost at lower frequencies, this typically results in the “boom” most people think is the fault of the sub (it isn’t). The clean and tight typically results in a sub incapable of hitting certain SPL goals you want. When a sub is fed too much voltage at a frequency it can’t properly produce you get distortion, unclean. When a sub fails to hit a SPL goal it is then said to not be “tight.”

A properly DSP’d sub in a box big enough to allow it to hit SPL goals it will sound perfect.


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#21 ·
Now if you want fast double bass, here's one of the best if not the best in the business. George Kolias is a beast. He plays double bass with a knee twist technique with a metal band called Nile.






But I digress. Lawdogx, would you please point me to some links about potential amp candidates?



Maybe a better description of my room will help. I think I should have posted this first. The room will be double drywall throughout, concrete slab. The walls where it cuts in to the right of the picture are 2x6 staggered stud walls. I have a build thread going on here:


https://www.avsforum.com/forum/19-dedicated-theater-design-construction/3120634-here-we-go.html


As you can see, there are opportunities for bass trap placements, and this is something I am going to pursue, also DIY. Bass traps are not a possibility for that top left corner, there is a small closet outside of the room there that will house amps.
 

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#23 · (Edited)
Never did I say it wouldn’t knock pictures off the wall , it would but between 15-45hz after that I was disappointed in its performance. I have a umik and REW and my subs are in the best placement throughout the room. Trust me I tried to make them work for music. I finally added some pa 460’s and all was good.

I’ve had sealed um 18’s , mini Marty um 18’s , full marty’s, um18’s , sealed pa460’s, vbss 460’s, full Marty eminence 21’s , and now 21” devastators . So I’ve tried about everything.

The um18 mini and full with pa460 was a nice setup.

The devastator’s are just on another level I love them. The best if everything.
 
#24 ·
I'm on a full concrete slab as well. I've had chest compression with my 8 HT18s for several years, but never quite what I was hoping for for music. For movies, the setup was great and exceeded expectations.

I recently added 2 NSW 21s in a Ricci data-bass design (skram). The music impact of these subs is uncanny. They also can be tuned to 31hz, 25hz, 20hz, and 14hz based on different blocking of the 4 available ports to work in the lower bass octaves for movies or different genres of music that utilize the lower octaves (e.g. Guys like Marcus Miller, dance/trance, etc.).

If your music tastes are in the realm of five finger death punch, tool, and the like, I would lean towards the PA driver based on the 60/40 or so usage. Having that double bass drum hit in a room from drivers like being 40 feet from live music on stage was something I was lacking. Not anymore. I think you'll have success as well with an NSW or similar in a skram or similar.
 
#25 ·
Whew, this is a ton of info, all of it good. The amps you are showing me as well as the Behringer amps on the GSG website are pretty alien to me. I get the basic idea but wow, a lot of controls involved. REW with mic will be in hand no question.

The Devastator looks crazy good but I question my building skills with such a complex structure. By contrast, the full Marty looks pretty easy. So many options and I'm just not sure which way to turn. I'm definitely sold going the DIY route though. Even just pricing makes more sense.
 
#27 ·
I'll have to look over the assembly instructions again, I might just be psyching myself out.

Question: If using a pre/pro such as the monolith htp-1, I shouldn't really have to worry about having full dsp functionality on the amp itself as the HTP-1 will handle that. I believe too that the HTP-1 will be implementing Dirac BMM also, so that would further decrease the need for another specific dsp. Do I have the correct train of thought here?
 
#30 ·
I think Dirac does well with the BMM but even without it should have adequate controls to work well to adjust parameters. I don't have mine yet, I'm still about 3 weeks away from having the room completed then I'll start assembling the rest of the system.



Question: With an amp like the Behringer that does not have dsp I assume the downstream equipment would have to include the crossovers, etc, yes? In looking at pics of the unit there don't appear to be any controls other than what looks like volume and of course power. The only other subs I've used have those controls on the plate amp so using a separate amp like this is new territory, hence the seemingly juvenile questions.
 
#33 ·
Okay, super and thank you.


I sent GSG an email last night and to my surprise I received a response from both John and Kevin. To get a response that quickly is just unbelievably fantastic in this day and age where most times you can send an email and not get ANY response. Extremely impressive so, I'm sold. There's no way I'm not going to go with GSG. I'm going to finish the room in the next few weeks and start assembling the system. I have an old but still excellent Velodyne DD15 and that will stay for now since it's all I have.


Perhaps off topic but to flesh out the system, I will be keeping my Paradigm Reference 100v.2 with CC center. There will be new surrounds that will eventually have the matching mains/center. For this I'm going to do a shootout for the surrounds (bookshelves) and will create a thread to document that. The amps are already in place, 2x Bryston 9BST and one Bryston 6BST for the LCR. Processor will be the HTP-1. Height speakers? Well I'm still debating this but the Sonance Mag8r's are the current frontrunners.


Once that system is in place I'll start doing some listening tests for imaging, etc. That should tell me a lot about the room and will drive what subs I can fit in there. I can't fathom how I would be unable to fit Devastators vs. Full Martys. 25x30x48 vs 28x24x42 (just rounding off the dimensions of course) shouldn't make a difference at all in this room and there is no WAF to worry about. She's excited for me!
 
#34 ·
Does anyone happen to have a list of clamps they used for either their Full Marty or Devastator? I'm going to build but not sure if I have the right size and number of clamps available.
 
#38 ·
For GSG subs I wouldn’t go the Kreg/pocket screw route. I’d recommend a surplus of Harbor Freight clamps, depending on which sub you choose (with the deva requiring more and bigger clamps). The way most of us do it is buy an insufficient amount, start building and realize you’re short, run to harbor freight and pick up a few more, then repeat.

Go on Harbor Freight Coupon Database. You’ll see coupons for various sizes for $5-$10 per clamp. I’d grab two 60”, two 48”, a bunch of 36” and a bunch of 24”. The whole lot should run less than $100, and you’ll have them on hand when the sickness takes hold and you decide to replace all your existing speakers with diy.

For the Marty I think the instructions show a method using tape and weights, and if those geniuses say it works then it surely does. I used clamps because I had them and everything felt more precise and tight. For the deva you absolutely need clamps and lots of them. I have a thread for my GSG deva build (including clamp recommendation) so you can see how I did it.

Also, having heard marty’s and devas, the devastators live up to their name! The box is not a very challenging build and it will deliver more of everything than the Marty. Finally, talk with Kevin or John about drivers if you go the deva route. I don’t know how much difference you’ll notice between the various drivers in that box, especially if your using an NX6K amp. John was recommending the LaVoce (and it was what Kevin was using in his own devastators). I don’t know if that’s still the case with the NSW but those guys could tell you for sure.
 
#35 ·
Tape can be used for clamping joints. However it is handy to have a few clamps, make sure they are longer than the longest dimension you will encounter.



A few small ( 6" range ) pistol grip clamps used with a 6"speed square can be used to ensure that corners end up at 90 degrees. Look for speed squares with a large triangular window near the corner for this.
 
#36 ·
Really you just need a few, maybe 4, 24”+ clamps. Bessy makes some cheap ones, small heads, weak screws but get the job done. Harbor Freight has some super cheap ones that won’t last very long or put much clamping power.

There is also the tape method.


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