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LCR RC-7 Hybrid TMM configuration Or MTM


ClintonH

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Decided a few weeks ago to try a build with matching LCR speakers behind a AT screen. Wanted to go RF-7's but they are just too large for my space and finding a used trio in Canada is pretty much not going to happen. So I have been buying parts to build my own in a size that fits my space better, here's what I'm working with.

 

3 - K-87-KV CD's with horns attached (ebay)

3 - RF-3 crossovers modded to RF-7/RC-7 crossovers (ebay)

6 - K-1122-OB 8" drivers which is the replacement for RC-7 8"

 

They will be mounted on the wall behind my screen and ran with 3 subs so 80hz and below is not a concern with this build.

Will be mounted upside down so the horn is at the base centered approx 38" off the ground.

Dimensions will be 36" tall 10.5" deep and 10" wide wich gives a internal volume after drivers etc of 1.35 cubic feet, approx 47% larger than a RC-7

Will be tuned to approx 55 hz.

Have the 8" driver measurements from the 120841 (RC-7) and the K-1122-OB driver (RF-35), WinISD has them within .5dB from 80 hz up. I'm guess the difference would be the test procedure I used to measure opposed to how the 120841 was done.

 

I went with 3 RC-3 crossovers for a few reasons, I got all 3 as well as all the upgraded parts (new caps and resistors) for less than I could find 2 RF-7 crossovers. And I was planning to upgrade the pieces anyway so it seemed easy enough to just that right off.

 

Few pics of the first one I built, if anyone sees anything wrong please post up and LMK as this is the first crossover I have ever touched. I have since put a few nylon tie wraps on the resistors to hold them to the top add on board. Took me about 3 hours from start to finish so I'm prety slow at this. LOL

 

RF_3_1_zpsvtaluhz2.jpg

RF_3_2_zpsmetcbon1.jpg

RF_3_3_zpslki3ajub.jpg

RF_3_6_zpsf25ofao4.jpg

RF_3_7_zpsdgxgkuar.jpg

 

Edited by ClintonH
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So thinking about it more I'm not 100% if I should be going with TMM or MTM, anyone have any thoughts on this?

 

I had time at lunch to do up a few baffles , pretty simple since they will be out of sight anyway. These will be cut out on my CNC router, I can easily do the either of the first 2 and they would be fully behind my screen. If I go the 3rd option the bottom would be just under the screen, not a deal breaker but it wouldn't be as clean.

Don't mind the blue cylinder in the pics, used my 3D printer slicing program for screen shots. lol

 

Hopefully I can get a port designed tonight and on the 3D printer in the morning, going with a rectangle flared top and small flare bottom if all works well.

 

Baffle_TMM_zpsqs6ameei.jpg

Baffle_MTM_L_zpsfpcyjnkd.jpg

Baffle_MTM_C_zps212laxyf.jpg

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My vote is MTM, make the baffle symmetrical.

 

I'm a fan of D' Apolito designs anyway, I think the sound coming from them sounds very blended.  My CF-4's are MTM and I turned one sideways once just for giggles and the sound was fantastic.  If you go MTM you will always have the option of going vertical or horizontal.

Edited by wvu80
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My vote is MTM, make the baffle symmetrical.

 

I'm a fan of D' Apolito designs anyway, I think the sound coming from them sounds very blended.  My CF-4's are MTM and I turned one sideways once just for giggles and the sound was fantastic.  If you go MTM you will always have the option of going vertical or horizontal.

 

Well you were the only vote other than myself. lol I decided to go with the MTM configuration but I could not center the layout, I forgot my new sceen wont allow the space to go below. :/

 

So here is what I ended up doing for the baffle layout, my CNC seems to have a messed up driver so I had to do these by had last night. I am 100% not a wood worker so don't judge. :P

Took about 3 hours to cut all the boxes holes etc and put this one together to the point the front baffle and braces are all that are left, need to go get some foam to line them with before I can go any further.

I will have a 2" wide cross brace front to back side to side on each side of the horn and on the last woofer, so 3 in total. I think that will be fine, about 6X what is in my RF-35. :o

Ended up with a internal volume of 1.4 cubic feet and a port tune of approx 54 hz, don't mine the cutting mistakes I will be filling those when the box is fully assembled. Like I say not a wood worker but I am a Autobody tech so I fan fill/finish NP.

How they will sit on the shelf behind the screen.

 

192016135449_zpszcuzqcsw.jpg

 

Test fitting the Horn in

 

19201613543_zps0no1pgia.jpg

192016135432_zpstmiv1eib.jpg

 

And a comparison for the RF-7 horn and the RF-35 just cause I had it out on the weekend.

 

RF-7_RF-35_zpsgzi2fk8w.jpg

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Last update on this until I measure in room responce since I'm talking to myself anyway. LOL :lol: But I'll be sure to close it off with how it all worked out, or didn't. 

 

Braces in, the top is braced by the port as it sits tight against the sides.  And one with it all together with a quick rolled out coat of primer, need to do a few more but shouldn't take long. The center speaker is all ready to brace up and put the front baffle on as well but no woofers yet.

 

111201694139_zpsaqxqzihk.jpg

 

111201694046_zpsx5umybjp.jpg

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Last update on this until I measure in room responce since I'm talking to myself anyway. LOL :lol:

 

I am with you my friend, and I bet a lot of other people are too.  

 

I'm not tech savy enough to advise, but it's fun to watch you work.  I have an idea for a "super center" as well, but I don't have the knowledge or equipment to make that happen.

 

Seriously, even though you may think you are talking to yourself what you are actually doing is adding to the general knowledge of the collective.  How cool is that.  B)

Edited by wvu80
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Last update on this until I measure in room responce since I'm talking to myself anyway. LOL :lol:

 

I am with you my friend, and I bet a lot of other people are too.  

 

I'm not tech savy enough to advise, but it's fun to watch you work.  I have an idea for a "super center" as well, but I don't have the knowledge or equipment to make that happen.

 

Seriously, even though you may think you are talking to yourself what you are actually doing is adding to the general knowledge of the collective.  How cool is that.  B)

 

 

Yep that's why I said I would report back with the outcome. :)

 

Couldn't wait so I put one together at luch, these will be using the woofers out of my RF-35's so I have to take one apart then assemble so I was only able to get one done. I lined the box with foam and a bit of poly in the top above the port and behind the CD driver, no poly behind the woofers only 1" open cell foam.

 

So here is what it looks like compared to my RF-35, not near as deep but not tiny either.  Agian don't mind the finish as this is just to see if they are actually going to work or not, also the angle on speaker is the basement concrete is super out of level. ;)

 

1112016144051_zpse2ijtnud.jpg

111201614400_zpsbybn6dol.jpg

 

And a quick measurement, I placed my RF-35 center of my screen yesterday and took a measurement raw that is the purple line. And one today witht he new speaker in as close of spot as I could raised off the floor with a chair, the yellow line. 

Both 36" back, not sure if this is useful at all to anyone but to me it looks like a winner and should just get better with a little Audyssey action. 

 

RC_7_RF_35_comp_zps7qgbveit.jpg

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Follow up on how the pair sound in place of my RF-35's.

I'm in the middle of redoing my theater setup to more of a open space rather than the dark dungeon I had going on so it's a WIP right now.

Watched American Sniper for the first time with these last night and They sounded fantastic, sound stage was far more dynamic and open.

I tried them without the Subwoofers on and can say for sure they don't dig as deep as the RF-35's but with the crossover on and subs on it's a non issue.  I cannot wait to have the matching center done and all behind a AT screen.

 

And just to see how the crossover mods worked I one with a stock RC-7 crossover and one with my current modded RF-3 and the sounds is so much smoother, I think that is the resistor mod that everyone loves so much so worth it. B)

 

11220169911_zps8um0yb20.jpg

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Interesting build and looking really good.  What did you do with the 35's?  I've been looking to pick up a single RF7 for a center too, or a ragged out pair to pull the components out of since I would redo the box.  Is that an inuke sitting on the floor?  I have one and the fan noise is over the top.

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Interesting build and looking really good.  What did you do with the 35's?  I've been looking to pick up a single RF7 for a center too, or a ragged out pair to pull the components out of since I would redo the box.  Is that an inuke sitting on the floor?  I have one and the fan noise is over the top.

 

Thanks. The RF-35's were used as donors for the build, so the 8" woofers out of these went into the new build. They are the replacement drivers for the RC-7's and measure very close (within 1/2dB through the range) for the original woofer. I am still waiting on the 2 new 8" for the center, everything else is ready. :)

 

Yeah that is a iNuke 6000DSP, it is currently running my JL 13W7 (seen on the left) and a near feild 12W7. I have a 2nd 13W7 that is also being used but I'm currently finishing the veneer on now. It has been fan moded and you can't hear it at all from 1' away.

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Is that an inuke sitting on the floor? I have one and the fan noise is over the top.

 

There are many threads on AVS.com on replacing that noisy fan that is quick and easy.  Let me know and I'll look it up if you have any interest.

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Interesting build and looking really good.  What did you do with the 35's?  I've been looking to pick up a single RF7 for a center too, or a ragged out pair to pull the components out of since I would redo the box.  Is that an inuke sitting on the floor?  I have one and the fan noise is over the top.

 

Thanks. The RF-35's were used as donors for the build, so the 8" woofers out of these went into the new build. They are the replacement drivers for the RC-7's and measure very close (within 1/2dB through the range) for the original woofer. I am still waiting on the 2 new 8" for the center, everything else is ready. :)

 

Yeah that is a iNuke 6000DSP, it is currently running my JL 13W7 (seen on the left) and a near feild 12W7. I have a 2nd 13W7 that is also being used but I'm currently finishing the veneer on now. It has been fan moded and you can't hear it at all from 1' away.

 

 

 

 

Is that an inuke sitting on the floor? I have one and the fan noise is over the top.

 

There are many threads on AVS.com on replacing that noisy fan that is quick and easy.  Let me know and I'll look it up if you have any interest.

 

I'll check out the fan mod, thanks for the tip, although I think that my inuke will stay in the shop rig and it may be a non issue out there, but if I bring it inside, I will absolutely have to do the mod, or give it to Denise to use as a blow dryer.

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I'll check out the fan mod, thanks for the tip, although I think that my inuke will stay in the shop rig and it may be a non issue out there, but if I bring it inside, I will absolutely have to do the mod, or give it to Denise to use as a blow dryer.

 

LOL!  I knew by reputation it was loud, but I never heard it put that way before!  :lol:

 

http://www.avsforum.com/forum/155-diy-speakers-subs/2300554-nu3000dsp-fan-mod.html

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I'll check out the fan mod, thanks for the tip, although I think that my inuke will stay in the shop rig and it may be a non issue out there, but if I bring it inside, I will absolutely have to do the mod, or give it to Denise to use as a blow dryer.

 

LOL!  I knew by reputation it was loud, but I never heard it put that way before!  :lol:

 

http://www.avsforum.com/forum/155-diy-speakers-subs/2300554-nu3000dsp-fan-mod.html

 

 

LOL you think the 6000 is loud you should hear the old EP2500 I had before, souded like a helicopter lifting off when it got going. :P

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