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HT Subwoofer project - Page 2

post #31 of 78
And I was thinking to stand it backside down so the driver is near 1/4 room height.smile.gifsmile.gif
post #32 of 78
Thread Starter 
Okay, I'm ordering up parts now.

I'm starting with the inuke 3000dsp discussed in the EP4000 thread. Too good to pass up. I'm going to run 2 MartySubs off of it. Hopefully that will be plenty with the size of my room. (620wpc RMS ~ 115dB@20Hz and 110dB@15Hz before eq)

Also, I'm going to do a pair of SI HT18 D2 so I'm at 4Ohms per channel on the inuke.

Any red flags with this plan?

Will be getting wood and bits over the next week.

Thanks for the help!
-Paul
post #33 of 78
I like where you are headed...



...but might consider d4's in parallel for 2 ohms per channel for 2x the power. ack ack.
post #34 of 78
Thread Starter 
I was unsure of using 2Ohm loads because some amps (this one excluded I think) have difficulty at that level. Certainly would be cheaper than getting a second amp to up the power.

Do you think there's any risk at 2Ohm? I've been known to overthink things....
post #35 of 78
just like the ep2500/ep4000 amp, 2 ohms *per channel* is fine on the 3000. in bridge mode, 4 ohms would be the min.

the 6000 is a little different in that it is essentially two bridged 3000's in one box. so for that one, it cannot be run bridged and a minimum of 4 ohms per channel is where you'd want to be.

all these get discussed so much that it can get a little confusing.
post #36 of 78
Thread Starter 
No worries on the confusion. The audiophile nomenclature doesn't help either. If it was all fundamental units and LaPlace transforms, it would make sense to me, but no one else... smile.gif

Anyways, at 2Ohms, 1040wpc yields 116dB@20Hz and 113dB@15Hz, so there is what one would call a "noticeable" (3dB) gain at 15Hz. Worth it in my opinion, since sub20Hz output (extension?) is why I'm doing this.

Next is wood selection. My better half approved Duratex for the living room, so that seems the no-brainer. I haven't built a cabinet in 25 years, so its nice to know minor mistakes can be hidden.

I'm thinking of going plywood instead of mdf for sawdust and weight. If I cut my own handy panels from a 4x8 sheet, the cost is a wash. Plus, living in Florida, water is always a (minor) risk, but I think ply would survive incidental water contact better than MDF.

Thanks!
-Paul
post #37 of 78
Thread Starter 
And so it begins.....


iNuke 3000dsp from uniquesquared on ebay


Subwoofer inspection. SI HT18D4... the size of the shipping boxes made me grin.... smile.gif

I found a local shop to cut the wood for me. $130 to cut up 4 sheets of MDF to LTD's cutlist. I'll just have to do the baffle cutouts and glue together.

The Duratex is here and I'm just waiting for Monoprice and Parts Express to arrive.

Any suggestions for making a grill? I ordered speaker cloth, but didn't plan out a frame just yet. We have 3 cats, so a cover is in order. Also, I did order neodymium magnets from Amazon. They are quite strong...
post #38 of 78
awesome!

the easiest way to make a grill would likely be to just cut another baffle board (slightly smaller to allow for cloth wrapped around the edges, but with a larger hole in it. the corner blocks provide for driver clearance.
post #39 of 78
Thread Starter 
Thanks LTD.

What about stuffing? I saw the guys lined their MartySubs, but it seems like an inexact science and I don't recall the discussion in the other thread coming to a definite conclusion....

Should I line the inside the box with 2" of insulation?

Also, when making the double baffle, should I put a clearance hole (18.5"DIA) in the top layer and a mounting hole (16.7"DIA)+bolt circle(17.5"DIA x 8 holes) in the bottom layer? Or just do the clearance+bolt in both to have the driver sit on top? Just wondering about the MDF supporting the 40lb driver.

-Paul
post #40 of 78
What type of EQ do you plan on doing? I know that traditionally people EQ sealed subs, but I have not seen many folks EQ a ported sub.
post #41 of 78
Thread Starter 
I have an inuke 3000DSP, so I'll use that if eq is needed.

-Paul
post #42 of 78
Quote:
Originally Posted by Atredeis View Post

Thanks LTD.

What about stuffing? I saw the guys lined their MartySubs, but it seems like an inexact science and I don't recall the discussion in the other thread coming to a definite conclusion....

Should I line the inside the box with 2" of insulation?

Also, when making the double baffle, should I put a clearance hole (18.5"DIA) in the top layer and a mounting hole (16.7"DIA)+bolt circle(17.5"DIA x 8 holes) in the bottom layer? Or just do the clearance+bolt in both to have the driver sit on top? Just wondering about the MDF supporting the 40lb driver.

-Paul
I think you mean mounting+bolt?

If you do clearance+bolt the driver will drop straight through the hole tongue.gif lol
post #43 of 78
Thread Starter 
You're right. I am asking about having the driver recessed into the first layer and mounted to the second.
post #44 of 78
Thread Starter 
Progress report. These things go together pretty easily.

Cut Lumber...


Just need baffles and bracing, then lining and priming...


Gluing baffles together, have to get longer bolts to mount the inserts and subs...


Any recommendations on liner material? I'm thinking of spray gluing insulation in there.
post #45 of 78
Quote:
Originally Posted by Atredeis View Post

Progress report. These things go together pretty easily.

Cut Lumber...


Just need baffles and bracing, then lining and priming...


Gluing baffles together, have to get longer bolts to mount the inserts and subs...


Any recommendations on liner material? I'm thinking of spray gluing insulation in there.

I put 2" of regular foam all around and sound is clean. Looking good. Two Martys will be thunderous . Be sure to give us listening impressions . smile.gif
post #46 of 78
Thread Starter 
Quote:
Originally Posted by chalugadp View Post

I put 2" of regular foam all around and sound is clean. Looking good. Two Martys will be thunderous . Be sure to give us listening impressions . smile.gif

Thanks man. I have to leave it alone for tonight. Tomorrow will be bracing, internal painting and trying to get at least the first coat of duratex on.
post #47 of 78
^^ think you will be bit by the diy bug and make more speakers ? I'm looking at building some seos offerings .
post #48 of 78
Thread Starter 
Great minds think alike. I've been reading all of the SEOS threads and am considering them for my next project. The MartySub will likely overwhelm my HTDs.

After these are done and set up, sizing up a good SEOS set will begin. The thing right now is the center channel as mine has to go under the TV.
post #49 of 78
The tux 1099 is coming out in the next couple of months and it looks like the perfect lcr . Seos based center channel . You are right the Martys will overwhelm your htd at very loud levels. Thing with Marty is they sound so good that I listen louder then before.
post #50 of 78
Quote:
Originally Posted by chalugadp View Post

The tux 1099 is coming out in the next couple of months

I sure hope you're wrong about this prediction !
post #51 of 78
Just a guess ^^. Tough to complain when prices are so good.
post #52 of 78
"Cut Lumber..."

i love that picture. :-)

to answer your question that i missed from earlier, no need to recess the driver unless you would like to. the blocks in the corners on the front of the baffle provide the spacing so that the driver will not hit the grill. the double baffle idea was for extra rigidity and to give the mounting bolts a little more board in which to bite reducing the risk of stripping a hole. the driver should actually hold in a single layer of mdf if mounted properly, but the double gives a little more margin for error.

a little stuffing will help reduce standing waves inside the box. a couple walmart pillows in there would be fine. the key is to not stuff it so tight that the air can't move. for a technical read, ricci has a nice discussion here: http://www.data-bass.com/data?page=content&id=79
post #53 of 78
Thread Starter 
Another question, I followed the One Cut variant of the MartySub and have a 32" port length. Is this correct? I saw the original had a 36" to hit the 17Hz tune. There is leftover material to adjust the length if I need to.
post #54 of 78
Thread Starter 
Bracing pictures. Don't think this skill will go on my resume.... ugly but effective....





Having breakfast while glue dries, then painting the insides....
post #55 of 78
Thread Starter 
Lid on, insides painted. Couldn't see what i was doing with the paint....

Got some R19 to put in there... I can add more, but hopefully this will be enough to damp any unwanted reflections.


What's better than a MartySub?



TWO MartySubs!
post #56 of 78
Thread Starter 
Has anyone used the Parts Express speaker grill kit?

http://www.parts-express.com/pe/showdetl.cfm?partnumber=260-346

I like the idea of these rather than trying to fit a piece of MDF in the front of the cabinet. (I don't have the tools to trim the MDF accurately)
post #57 of 78
Thread Starter 


DuraTex is great stuff. Coming right along. Hopefully I can power them up this weekend.
post #58 of 78
Looking good. Almost ready to rumble !
post #59 of 78
Alright, looking good! COOL!
post #60 of 78
Thread Starter 
MartySubs are done and online.


First listening impression... be careful with the gain knob. Made my eyes cross with some EDM.....

Have them calibrated with Audyssey and it is excellent. A definite improvement over the 12" HTD... reminds me I have to update my sig.

There is a hum when the input gain is cranked. I'll have to hunt that down.... hopefully it will be something simple like grounding the AVR chassis.
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