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Discussion Starter #1 (Edited)
UPDATE 7/13/19

Decided to go with AE drivers for the MidBassModules for the Quested Audio LT-20 LCRs.

2 Custom Built 18s per LCR in Face to Face alignment based on the TDH+ driver. He is constructing them in a different way where the venting and phase plug connect to the cone is my understanding.

I think I can fit 4 of my 6 SI Mkiii 24s in face to face alignment as well to help reduce cone surface area behind the screen.

Drivers officially paid for and being built. He listed the changes to the TDH+ design in the invoice as far as what he calls them. He said the specs are the same except a couple grams of mass are added in this configuration.



Now I need to power these suckers with something nice and clean!!! I haven’t decided yet if will use 240V or 120V. I’m running out of 240V amperage so most likely will give them 120. Upgrading my 240 sub panel is not out of the question though. All it will take is aprox 40’ of whatever gauge wire I want to pull larger than what’s there now so not a huge deal at all.





Hi everyone.

I’ve been planning and planning for the past 5 years or so on my front Baffle Wall/Room Design and am finally about to start construction once I have this last piece of the puzzle figured out, and whenever Nick finishes last years Black Friday 24” delivery.

Ok. I need Sealed MBMs for the LCRs and have narrowed it down to 3 options but would be happy if an option was possible that fit better for sure.

All options are sealed!

Option #1 Dual AE 18s in a dual V/U shaped manifold cabinet.

Option #2 if will work Dual Eminence 4018 18s in the same type V/U shaped manifold.

Option #3 Dual Eminence 21” in V/U shaped manifold.


I have attached very crude drawings showing my space to work with. You will notice that the 36” width will not fit on the same baffle as the L/R speakers so part of the enclosure will be nested into the center section of the baffle wall. This is doable but will make it difficult accessing the cabinet if something happens to the drivers once the baffle wall is sealed up.

Second issue is the 36” width also makes mounting my ULF 21” and 24” drivers flush with the L/R baffles impossible. I would have to mount them parallel with the side walls. I don’t mind sliding the 21”/24” subs perpendicular to the MLP at all as long as the loading on the drivers will be okay in this orientation?

I need to figure out a way to house six 21” and six 24” subs on my baffle wall along with the LCR mid bass modules.

Here are some pics of the space I have to work with. The overall baffle wall can be manipulated to an extent but the locations of the LCRs and Lc/Rc cannot be moved at all. I would rather not mess with the baffle wall design because renders of the entire room are being made and the “behind the screen” subs have been left out of the renderings for obvious reasons. But, I have designed an elaborate web type of front screen wall that will mount to the baffle wall how I have it drawn in these pics so changes would really be taking more than a tiny step backwards. Anyone that has been following my build knows that it has been in the design phase for about 3-4 years too long now lol. But it’s finally coming together and have my next order of Quested speakers on the way so am anxious to finally utilize my Altitude32 with 3D sound instead of only ear level speakers.

Sorry for the ramble.

Here is what we have to work with and what designs @Mark Seaton has helped with in the manifold suggestions.





Bests
Alex


Here are Mark’s suggestions regarding a manifold that will fit but obviously my initial space of 26” opening with even more space to the sides SHRUNK quite a bit once the all the screen cabinets were placed exactly where they had to be located.



Per Mark-
A 26" wide opening is much easier than a 26" wide box. You can either just build them on a flat face with the drivers set back slightly with only 4" of the edge of the woofer concealed, or you can angle the drivers at 30 degree on the manifold with a ~22" wide opening, 36" wide box, 18" deep, 26" tall and you will have the right volume (figuring ~0.75" material).
With the 30 deg/22" wide manifold or flat mounting with 26" square window over the drivers there's not really anything to worry about in the loading.
So far as the shallow 18s, I have the sample of our upcoming production cabinet here that is 12" deep, 26" x 30". E-mail me if you need further info.


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Discussion Starter #2
Here is what concerns me about the space left for the 21”/24” sealed subs to the left and to the right of the L/R MBMs.





The pic of the baffle wall was just to see how the 21”/24” subs could fit flush to the baffle wall. The 21” subs above and below the LCRs are being represented as Eminence 21s but I don’t like how they have to be “above and below” the Mains cabinets. Would this affect how they all perform together or would it be just as good as having a manifold with both grouped below the LCRs? This would be the easiest way to go being that they could all fit very easily and accessing each separate sub/mbm cabinet would be very simple.




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Discussion Starter #3
This pic shows three 24” drivers on the far left and right baffles for a total of six 24” ULF subs.




It has 8 FTW Mach 5 21” ULF subs.

And it has 6 Eminence 21” drivers for the LCR extension/MBM but they have to be placed above and below each LCR so am hesitant if this would be optimal?

Will placing the drivers above and below the LCRs create any negative effects? I assume they are still close enough together that they will act in summation? The LCRs are 27” tall so after shelving aprox 28.5” then add center to center of each 21” and that would be a spacing of 51”. This would create 51” from center of the lower 21” to the center of the upper 21”.


I’m scatter brained and keep thinking of other stuff I need to add. Sorry!

Bests
Alex


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Questions. In one drawing it looks like you only have 19.9" of width to play with and the subs are mounted on the side of the cabinet, shooting toward the 6" wall. In the drawing below that, it shows the subs mounted on the front of the baffle wall, but 21" or 24" drivers will not fit in a 19.9" space? Also I assume the manifold for the MBM's is made like a sideways "U" so that you have a recess to place the left and right Quested LCR? Looks like you have more depth behind the MBM. Why can't you make it deeper and then make it narrower on the side toward the sub. That way the sub box can be wider on the front and fit the drivers on the front face of the baffle wall? As for drivers for the MBM, my vote would be for the AE TD18's. I use them in my LCR's. Great drivers.
 

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I don't think the bass coming from that front wall will be a problem.
I'm more worried about your screen flexing to the point of being blurry.
Also, those front tops are gonna have different dispersion than the rest of them.

The above/below is a fairly far distance, hopefully with your LPF that won't cause comb filtering.
 

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Discussion Starter #6
Questions. In one drawing it looks like you only have 19.9" of width to play with and the subs are mounted on the side of the cabinet, shooting toward the 6" wall. In the drawing below that, it shows the subs mounted on the front of the baffle wall, but 21" or 24" drivers will not fit in a 19.9" space? Also I assume the manifold for the MBM's is made like a sideways "U" so that you have a recess to place the left and right Quested LCR? Looks like you have more depth behind the MBM. Why can't you make it deeper and then make it narrower on the side toward the sub. That way the sub box can be wider on the front and fit the drivers on the front face of the baffle wall? As for drivers for the MBM, my vote would be for the AE TD18's. I use them in my LCR's. Great drivers.


Hi Mike been a while. Hope you are doing well man!

Yes on the image with the all the drivers flush the 24s will fit because the U/V style cabinet is not intruding into that space.

I might could do exactly as you suggest that’s why I’m asking for help as I don’t know all that tech stuff about pushing impedance into the passband and such so wouldn’t have a clue if my model was good or bad.

Mark Seaton Gabe me those dimensions for the 36”x26”x2(x)” cabinet for the AE driver but never mentioned the Eminence drivers in the manifold type cabinet.

Obviously flush mounting all the drivers like in that mockup pic I did just to see if they could be flush mounted would be easiest but like I mentioned I don’t know how spreading the two MBM drivers to above and below each LCR would work.

I will draw you a pic and add it to this reply in just a minute. I will actually just reply twice so you see notification on second thought.

Bests
Alex


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Discussion Starter #7
Questions. In one drawing it looks like you only have 19.9" of width to play with and the subs are mounted on the side of the cabinet, shooting toward the 6" wall. In the drawing below that, it shows the subs mounted on the front of the baffle wall, but 21" or 24" drivers will not fit in a 19.9" space? Also I assume the manifold for the MBM's is made like a sideways "U" so that you have a recess to place the left and right Quested LCR? Looks like you have more depth behind the MBM. Why can't you make it deeper and then make it narrower on the side toward the sub. That way the sub box can be wider on the front and fit the drivers on the front face of the baffle wall? As for drivers for the MBM, my vote would be for the AE TD18's. I use them in my LCR's. Great drivers.


Ok here I have the Right LT20 shown from above sitting on top of the U/V type cabinet.

I drew another more detailed drawing from above of how it would look if the LT20 wasn’t in the way.

It’s basically like Rob Hahn’s Uber Subs, Procella, and a few other brands. Two drivers facing each other either on an angle or parallel to each other.



Hope that helps.

Bests
Alex


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Discussion Starter #8
I don't think the bass coming from that front wall will be a problem.

I'm more worried about your screen flexing to the point of being blurry.

Also, those front tops are gonna have different dispersion than the rest of them.



The above/below is a fairly far distance, hopefully with your LPF that won't cause comb filtering.


Yea I’m rotating the LT10s on their side which will match my custom Z8s which are also oriented as side by side design with AMT tweeter and 8” driver so not worried about that. The AMT is oriented the exact same on “ALL” the speaker cabinets (have been rotated on the custom Z8s and LT10s) so not a huge deal. The AMT drivers have such a narrow horizontal dispersion which is why they are all being aimed directly towards the MLP.

Now the Above/Below distance regarding the MBMs that I am obviously worried about.

Tell me more Bass...

Bests
Alex


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Discussion Starter #9
I am trying to manipulate the enclosure like Mike G said so that the side closest to the wall can house the 24” subs and am running into mounting depth issues of the AE TD18H+.

Only info I can find says the driver is 12” deep. Does anyone know the actual mounting depth of the driver?

Bests
Alex


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Discussion Starter #10 (Edited)
Here is what I have drawn up real quick with Mark’s figures. These were based on the AE drivers.




This is aprox 96 Liters per driver before wood, driver, and bracing.


Anyone have any tweaks or changes they would make?

What about the “V” where the baffles meet the back of the cabinet, would anyone suggest a more “U” shape or space between the baffles?

Bests
Alex


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I am trying to manipulate the enclosure like Mike G said so that the side closest to the wall can house the 24” subs and am running into mounting depth issues of the AE TD18H+.

Only info I can find says the driver is 12” deep. Does anyone know the actual mounting depth of the driver?

Bests
Alex


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Here is a drawing.
http://aespeakers.com/pdfs/TD18_dimensional.pdf
 

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What about placing the MBM under the left and right speaker. You would need to move the lower two 24" subs closer to the top 24" driver. Make it angled like Mark shows it, but reduce the total width a few inches. Whatever volume you lose by reducing the width, add depth to pick it back up.
 

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Discussion Starter #13
What about placing the MBM under the left and right speaker. You would need to move the lower two 24" subs closer to the top 24" driver. Make it angled like Mark shows it, but reduce the total width a few inches. Whatever volume you lose by reducing the width, add depth to pick it back up.


That’s exactly what I’m working on now. I emailed them for the mounting depth but now have that info from your post. Thanks!

I am also trying to find the mounting depth of the SI Mkiii if your able to find it or know it with another idea I am toying with as well. I’m also trying to squeeze space across the bottom with 24s or 21s in face to face alignments if anyone can give the okay to cut wood with these types of alignments.

I think it would be better having the majority of the drivers along the bottom for both ease of construction and acoustically. When I had all 10 21s along the bottom before the FR was easily managed.

I’ll work with the MBMs and post pics of what can come up with.

Thanks again!

Bests
Alex


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That’s exactly what I’m working on now. I emailed them for the mounting depth but now have that info from your post. Thanks!

I am also trying to find the mounting depth of the SI Mkiii if your able to find it or know it with another idea I am toying with as well. I’m also trying to squeeze space across the bottom with 24s or 21s in face to face alignments if anyone can give the okay to cut wood with these types of alignments.

I think it would be better having the majority of the drivers along the bottom for both ease of construction and acoustically. When I had all 10 21s along the bottom before the FR was easily managed.

I’ll work with the MBMs and post pics of what can come up with.

Thanks again!

Bests
Alex


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I have the TD18H+ info because I needed it for setting up delay with my TD12M's and TPL-150H AMT tweeter.
 

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Discussion Starter #16
I just wanna salute this total overkill effort. I have 2 24” sealed, six is gonna be cool. What’s the dimensions of the room/room volume?


The foundation/original room is 33.75’ x 17.85’ x 10’ but the baffle wall takes up space as well. Its new interior dimensions will be roughly 29’ x 16’ x 10’. I’m making all the walls flush with the acoustic plan basically which will house speaker cabinets inside the walls.

And it’s six 24s and eight 21s just on the screen wall for ULF. That’s without the MBMs and other subs scattered throughout the room.

Bests
Alex


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Discussion Starter #17
Here is best I can squeeze the cabinet while also feeling comfortable getting the drivers screwed into place without dramatically angling the screws closest to the “V” in the rear of the enclosure.

I come up with aprox 96 liters per driver without driver displacement and bracing.

The cabinet is 23” deep on the inside and 26” tall. I don’t know how these dimensions affect 1/4 wavelengths etc... but assume I just take a wavelength that is equal to 23” and 26” multiplied by 4.

130hz equal 104” so 26” would make it the the 1/4 wavelength?

Is that a bad thing being that I will run these up to 100hz maybe higher?

Any changes anyone see that may need to be made?



Bests
Alex


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Discussion Starter #19
With that wild wall of woofers, is there any particular reason you don't go for a proper SBA and be done with the bass once and for all? In case you never seen a SBA take a look at mikela's HT: https://www.avsforum.com/forum/19-dedicated-theater-design-construction/1946625-mikela-s-sba-trinnov-theater-build.html


Yea there actually is a reason. The LCRs are required to be in those locations exactly so the subs won’t fit where they would need to be for a SBA.

Bests
Alex


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Discussion Starter #20
With that wild wall of woofers, is there any particular reason you don't go for a proper SBA and be done with the bass once and for all? In case you never seen a SBA take a look at mikela's HT: https://www.avsforum.com/forum/19-dedicated-theater-design-construction/1946625-mikela-s-sba-trinnov-theater-build.html


Mashie that was just to see if they would fit. I’m hoping someone will tell me if the manifold MBM will work like I have it then will play around with the wall again.

I’m going to have quite a few flush faced subs on the wall unless someone chimes in and explains how these face to face enclosures work. I know how to model them in hornresp no problem but that doesn’t do me any good when I don’t know what to look for in the graphs.

I’ve actually posted about these types of enclosures twice and how to model them but nobody ever really breaks the concept down. People have taught me how to properly model them which I’m more than thankful but with that alone it’s not providing much data.

I’d much rather have all the subs in manifolds on the wall just for acoustic reasons. But, if nobody shows up I’m just going to try to space them out flush so that as much space behind the screen as possible will be covered in material rather than cones.

The SBA would have been cool and all but I’d still add more subs around the room regardless so not a big deal. With this many subs on the wall I’m betting it will still have quite a few characteristics of a SBA once the final measurements start rolling in. Will see when get there for sure.

When I had ten subs along the front the seat to seat was pretty spot on but the row to row was different which is pretty similar to a SBA and that was only with drivers along the bottom.

Will see what I come up with. Sealed flush mounted will be the easiest for many reasons but if can use face to face will try to for sure.

Bests
Alex


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