# Need to conceal a center channel... Build it into the matle!



## yamahaSHO (Nov 14, 2007)

Our house always had a mantel that has been way too high which placed the TV much higher than I could stand. I decided to rip it off so I could lower it an mount the TV on the wall above it. It's still not going to be as low as I'd like, but it is what it is. I also took the opportunity to make my own mantle and also make it my center channel speaker.

The start... cutting the wood:









Building:


















Ready for routing and a finish:










Ready to be mounted:









Size comparison:












In the process of tearing the fireplace area apart, I beefed it up, mounted the TV mount, cut some holes, route wires, etc. I also routed wires to the rear speakers, which I also wanted more concealed by doing in-wall speakers.



















What it previously looked like:












































So far I'm really digging this setup! Yes, I'd like the mantel a little lower as well as the TV, but this is what I was working with... And I don't have additional speakers and wire anywhere. I have a buddy coming over to weld up some trim around the fireplace for me, but it's currently looking like this.



















I ran a sweep about a week ago, but I have since picked up a better mic and am going to take a few different measurements tomorrow, before adjusting the crossover. The tweeter is very hot by this sweep, but it could be my mic position as well as I was using a Radio Shack dB meter.











Components used in the mantle are:

Dayton Audio ND140-8 5-1/4" Aluminum Cone Midbass

B&C ME45 1" Exponential Horn 90x40 2-Bolt 294-622

B&C DE120 1" Neodymium Mylar Compression Driver 8 Ohm


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## yamahaSHO (Nov 14, 2007)

I should have a grill done by this week, so once that's done, it should really hide the speaker aspect of the mantle.


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## dreadknot (Jun 9, 2017)

my suggestion it add an extra 1.5in to the front of that speaker baffle flush cut the driver mounts an then mount that center below your fire place with an upward angle of 10 - to 20deg which ever lines up with your head at the sitting position

an bring your tv down flush with the top of the fireplace to the bottom of the screen
plus i wouldnt have gone with that tweeter its sensitivity SPL: 106 dB 1W/1m is way to high the the madbasses 84.5 dB 2.83V/1m 

normaly you really want to have sensitivitys balanced 

if you have the means or know how to add a 21.5db attenuation to that crossover that would most definitely help make the tweeter less hot but the can be difficult and expensive

a simpler option is to return that B&C DE120 for this Dayton Audio DC28F-8 1-1/8" Silk Dome Tweeter


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## yamahaSHO (Nov 14, 2007)

Eh... Not doing any of that. Seriously, based on the goals, why would I put a center channel under the fireplace? It is a mantle! 

The tweeter is the same tweeter I have in my La Scalas, why would I do something different for the tweeter? There are 4 mid-bass drivers and I've stepped the tweeter down in the crossover I built, which is what I'll test more tomorrow. I stated above that the measurement may not be accurate and that I got a proper mic and will make several measurements. Heh... It's pretty common to step a tweeter down. 

The design was done to match exactly how the Klipsch are done/mounted and there will be a grill that sets in that recess.

BTW, it sounds great.


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## dreadknot (Jun 9, 2017)

just to line up the tweeters with ear level i find that most important to my listening position , an i didnt know your fronts spec

btw what are ther


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## yamahaSHO (Nov 14, 2007)

My ear level is not on the ground. In fact, that would put it further from my ear level. I've already done a theater in the past... A living room is a compromise. This was far better for placement, but it rarely got used. 











My specs? Which ones?


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## yamahaSHO (Nov 14, 2007)

Took some new measurements... I knew I might have been too close with the last one showing the tweeter being hot. I always thought it sounds like it may be attenuated too much and it appears I was right. 

1-meter away. 


Listening position. 




I may redesign the crossover a little bit as it's got a 2k hz hump.


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## theJman (Mar 3, 2012)

Very nicely done! I wish I had trade skills like that, it must be nice to see something in your head and then have your hands be able to create it. The look of those Klipsch never gets old...


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## yamahaSHO (Nov 14, 2007)

Thank you. I was pretty happy with how it turned out. I am going to redo the front panel, in that I am going to sand and coat in Duratex. Hopefully I'll have the crossover adjusted nicely soon.


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## fokakis1 (Feb 29, 2012)

Very nice! I've been fighting the urge to move the Cinema 7 down into my mantle. As you can see it's about 9 feet up and above the tv. Doesn't sound bad for a living room setup, but I bet you noticed an improvement when you lowered yours.


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## AEIOU (May 3, 2011)

yamahaSHO said:


> I should have a grill done by this week, so once that's done, it should really hide the speaker aspect of the mantle.


Hopefully you make a GRILLE, because to grill is to cook.


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## AEIOU (May 3, 2011)

yamahaSHO said:


> Our house always had a mantel that has been way too high which placed the TV much higher than I could stand. I decided to rip it off so I could lower it an mount the TV on the wall above it. It's still not going to be as low as I'd like, but it is what it is. I also took the opportunity to make my own mantle and also make it my center channel speaker.
> 
> The start... cutting the wood:
> 
> ...


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## AEIOU (May 3, 2011)

Very nice work, you certainly did a good job, it looks great and hopefully sounds great.


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## yamahaSHO (Nov 14, 2007)

Yeah... That.


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## thescher (Feb 15, 2015)

Man, that's some really nice work & I bet it sounds much better than most centers as in "yes size does matter!!" I used to use 2 JBL L-26s as my centers & what a difference the 10" woofer & a great vintage JBL tweeter made. I know there is not a lot of Sub-lowend frequencies being programmed to the center but it was the low-mid that was so much better with a larger speaker/woofer & center speakers in Cinema duty (movies, TV etc) do 80% of the work that the other speakers do (unless it's music which uses the front buss). All the dialog, which is low-mid to highs, come through the Center buss so the bigger the better, I say! Unfortunately, I do not have the width space to use them anymore so I hung, with plant hangers, 2 JBL Control 5s which sound a little brighter & a little less fuller (only 6" woofer) but do the job nicely. I was wondering why you wouldn't have thought about some built-in shelves to the left from your archway to the chimney instead of that little rack you have to the left side. I have been wanting to do one at my house as I have no mantel or chimney but a desk. Need to build some built-in shelves around the TV & a desk at the bottom with a rack to the side. As you can see I have a lot of **** jammed into a small space & I think built-in shelves around my TV with a rack to replace my old tired metal & glass shelf on the left, would give me places to organize things & prevent it from being so cluttered. Also, I have the JBL Control 5 official wall mounts that I could mount to the wall with the backing board of the built-ins. Right now I have very thin drywall & could only mount/hang the Control 5s where I had a stud. As you can see I have everything is kind of mismatched symmetrically & crammed into a small living room between a Front door/closet door to my right & a wall to my left. Thinking of putting built in shelves where the rack is now & make an access hatch through the side wall underneath where the picture is now, to work on the wiring so I can get behind it easily. The whole wall would be built in desk below & shelves all around the TV for speaker placement & books etc.


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## Mbsaro (Nov 28, 2020)

I was asking why you wouldn't have pondered some underlying racks to one side from your entrance to the stack rather than that little rack you have to one side. I have been needing to do one at my home as I have no shelf or fireplace except for a work area. Need to construct some inherent racks around the TV and a work area at the base with a rack aside. As should be obvious I have a great deal of **** stuck into a little space and I think worked in racks around my TV with a rack to supplant my old tired metal and glass rack on the left, would give me spots to put together things and keep it from being so jumbled. Additionally, I have the JBL Control 5 authority divider mounts that I could mount to the divider with the sponsorship leading group of the fabricated ins. At Tutuapp 9apps Showbox this moment I have meager drywall and could just mount/hang the Control 5s where I had a stud. As should be obvious I have everything is somewhat jumbled evenly and packed into a little lounge between a Front entryway/storage room entryway to my privilege and a divider to one side. Considering putting worked in racks where the rack is currently and make an entrance incubate through the side divider underneath where the image is presently, to deal with the wiring so I can get behind it without any problem.


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## yamahaSHO (Nov 14, 2007)

I have considered a rack, however, I am not sure it will save much aside from getting anything off the floor. I will have time to decide what I want to do before we paint the walls. I think I'd rather put most of it below the floor in the basement as HDMI CEC and apps have made little need to have anything in the room.


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## 123Toid (Mar 21, 2017)

yamahaSHO said:


> Took some new measurements... I knew I might have been too close with the last one showing the tweeter being hot. I always thought it sounds like it may be attenuated too much and it appears I was right.
> 
> 1-meter away.
> 
> ...


Are you using a traditional L-pad? I only ask, because it look like you are having an issue with your R1 being a little too hot. It's really hard to say without seeing the whole crossover design with the separate measurements. Either way, when you run R1 too hot, it will shape the tweeter with a hump at the crossover point and create a downward slope Similar to what you are seeing here. Of course, this is just a guess without seeing the individual measurements and crossover. Here are a few pictures with the peerless corundum tweeter as a reference. 

Notice with R1 set properly, the response stays nice and flat.










When R1 is too high you create that rise in the crossover region with a downward slope. I am only saying this, because it feels like you should be receiving a much better response than you are measuring.









I hope this helps you and if not, someone else.


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## 123Toid (Mar 21, 2017)

123Toid said:


> Are you using a traditional L-pad? I only ask, because it look like you are having an issue with your R1 being a little too hot. It's really hard to say without seeing the whole crossover design with the separate measurements. Either way, when you run R1 too hot, it will shape the tweeter with a hump at the crossover point and create a downward slope Similar to what you are seeing here. Of course, this is just a guess without seeing the individual measurements and crossover. Here are a few pictures with the peerless corundum tweeter as a reference.
> 
> Notice with R1 set properly, the response stays nice and flat.
> View attachment 174818
> ...


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## yamahaSHO (Nov 14, 2007)

That's actually the advertised curve of that driver. The hump is from the bass drivers. I know what I need to tame it, but I got some assistance from one of the pros to help design a different crossover. I've purchased the parts, but have not had time to build it yet. It's about $200 worth of parts and it will crossover much lower and extremely steep on the tweeter. I will be going from an L-pad to an autoformer for stepping the tweeter down this time. 

My tests wouldn't be the most accurate way to do it, but this next crossover should be a bit better. As it stands, I can tame the hump and step the tweeter up to match levels and it'd be fine.


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## 123Toid (Mar 21, 2017)

yamahaSHO said:


> That's actually the advertised curve of that driver.


Not to argue with you. But according to B&C in their tests and waveguide, their response differ significantly from what you are stating as their advertised response curve. It isn't the advertised curve in their spec sheet at least. Of course, putting it in a different horn will affect it. But down 30db at 15Khz shouldn't be normal for this driver.


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## yamahaSHO (Nov 14, 2007)

I can remove the crossover from the equation and that curve does not change... Even in the crossover software. It is what it is. 

That said, the person I worked with on my new crossover had me send him a bass driver to test as he said he can never trust published specs. He already had plenty of data on the tweeter.


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## 123Toid (Mar 21, 2017)

yamahaSHO said:


> I can remove the crossover from the equation and that curve does not change... Even in the crossover software. It is what it is.
> 
> That said, the person I worked with on my new crossover had me send him a bass driver to test as he said he can never trust published specs. He already had plenty of data on the tweeter.


I know you think you have it worked out. However, coming from a loudspeaker designer who does this for a living, what you are saying doesn't make any sense. It is true that you shouldn't trust a manufacturers specs, but when we say that we are typically talking about t/s parameters. Not saying the response won't change, it absolutely can and will, based off the box size and geometry. But generally well known driver manufacturers response graphs are fairly accurate. The response graph that you posted versus B&C's is drastically different. So much so that any designer would and should be asking why. Is it that you are measuring drastically off axis? Is it that you aren't measuring it correctly? Is the measurement microphone bad? Or is it that the driver itself was bad when it came to you? Or is your design so bad it is causing this? Or is it a bad implementation of the crossover? Any and all of these could be an issue. Truthfully what you have posted, from a designers standpoint, doesn't add up. Even if you change woofer, you are still going to have no top end, until you figure out why your measurement is so far off. If you ever want to learn how to implement it correctly, let me know.

Here are some videos that can help you at least make sure you are getting your measurements correct. 




How to di it in Xsim: 




and one by Scott to make sure you have Rew setup correctly.


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## yamahaSHO (Nov 14, 2007)

In regards to the tweeter. It takes the same dive without a crossover... I literally cannot be more clear than that. I have also had help in the new crossover by someone who has been doing this for years and makes crossovers for Klipsch speakers. The design I will build does not reflect what's currently in there. 

I was never stating I'd change the woofer. I can reduce the 2k hz hump with a 12 Ohm 12 uF Zobel. 

I have 5 DE-120's here that I can run a sweep with (La Scala and Heresy). I will be firing up my rebuilt Heresy speakers this weekend and plan to run a sweep. The mic for these sweeps (except the initial) is a brand new UMIK-1. Could I have a bad driver? Possibly. The sound itself doesn't lead me to believe, but I also have one driver that hisses more than the other in installed speakers. 

All that said, the sweeps you are stuck on aren't going to be the crossover used in the final... So I really don't put much thought into it. Please stop trying to chase this one as I've already stated it's a first run and another is being built.


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## yamahaSHO (Nov 14, 2007)

Finally got a chance to put together the new crossover... It's crazy how you set something aside and forget for months. It's not as pretty as I'd like, but it won't matter as it'll be in a box.







I will test it out and take sweeps tomorrow. Hopefully this is where I want it as I'm not really keen to keep messing with it.


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## yamahaSHO (Nov 14, 2007)

Quick sweep after putting in the new crossover. It sounds better! I may try reversing the polarity of the tweeter and seeing how it does.


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## yamahaSHO (Nov 14, 2007)

Finished up the grille, which I was actually tired of looking at the drivers. I'm happy with how it's turned out and now I just have to caulk and finish up the fireplace.


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## dreadknot (Jun 9, 2017)

what color are you going to go with for the concret personaly id go with a burgandy red with a semi gloss even on the speaker cabs


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## yamahaSHO (Nov 14, 2007)

I don't know what you're talking about... And nothing burgundy red is going anywhere here.


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## theJman (Mar 3, 2012)

That looks really nice, and best of all when you show it off you can say it was your design. Glad everything worked out so well.


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