Looking to run a true 5HZ signal to my Sub woofers but think my anthem receiver will Bottle neck this.

[TLS Guy]

Thanks! At this rate, my daily interrogation session is going to redesign this whole project from scratch. But hey, size matters, right? I'm leaning toward bigger boxes now, just praying I don't send the voice coil into orbit past Xmax

I think you would have to be an idiot to destroy those drivers. Yes, the optimal box volume is 8.2 cu.ft, but you have to add the volume of the driver and bracing to that. Bracing is crucial or it will "ring like a barrel". I must reassure that with the optimal design, those drivers should provide first class low end reproduction. The only caveat is, as long as the specs are correct and honest. Hopefully they are.

Keep us up to date on your progress.

 

[lovinthehd]

The drivers he has ordered are high Qts drivers and are only suitable for sealed alignment. As you know I favor sealed alignments over ported as the drivers are not so stressed. Sealed is probably my least favorite alignment.

My favorite as you know is aperiodic transmission designs. They have the deepest, cleanest bass for much less power. I don't need a lot of power to drive my lines, but when the grandkids come over for a movie night it rattles the crockery downstairs. So there is no trouble capturing the LFE channel in full.

Meh, could just be rattling furnishings from that description rather than actual performance. How much power is needed, what's the sensitivity of your TL stuff?

 

[TLS Guy]

Sometimes it's just not your taste, we get it. Your pre-pro is massively different, your Quad amps are the best, you make the best speakers, only you can setup a bloody cartridge, bla bla bla. Gets tiresome. Depends what OP wants, not what you would do in any case.

SME arms have significant differences to other arms and going though it the first time is very helpful. Don't forget I had to repair that turntable, as it arrived it was unusable.

 

[TLS Guy]

Meh, could just be rattling furnishings from that description rather than actual performance. How much power is needed, what's the sensitivity of your TL stuff?

Since there are two drivers in each of the dual lines, 92 db. You can tell the amps are not pushing hard though, as they barely get warm. With 3,200 watts, I have a lot of reserve.

 

[lovinthehd]

Since there are two drivers in each of the dual lines, 92 db. You can tell the amps are not pushing hard though, as they barely get warm. With 3,200 watts, I have a lot of reserve.

You have 3200 watts to your subs? With those Quad amps?

 

[TLS Guy]

You have 3200 watts to your subs? With those Quad amps?

No! The whole system. There is no sub in the classic sense, both the drivers in the long bass lines handle the LFE signal, but the upper of the two 10" drivers in each speaker, handles the BSC for the mids in the shorter line to offload them. The BSC is also variable, so can be set precisely under instrument control. The power to the four 10" drivers total 600 watts. The power to the shorter lines is 300 watts per channel, for a total of 900 watts to the front left and right speakers. Power to the center is 300 watts. So a total of 1200 watts to the front three speakers.

 

[Allen Vos]

Well Bass Box Pro, is very good at sizing the enclosure correctly and the optimal enclosure size for those drivers is 8.2 cu.ft. You should add the driver volume to that. You can see that from the graphs. It gets the 12 db. point exactly an octave below the 3 db. point which is where it should be. So you will be 10db or so down at 10 Hz with the 12db roll off around 20 Hz. With room gain, which there always is, the bass will be deep and natural.

I have to say the infrasonic range below 20 Hz is really not very important, and it barely makes a wit of difference whether it is there or not, and some say it should not be there. I can tell you it is not worth the trouble to chase it.

This sub craze has been a distraction, and I think in many ways has downgraded systems. By far the most crucial range is between 400 HZ and 5KHz. The reason is that is because it is the speech discrimination band, where the ear is most sensitive to aberrations. This tends to be the band most neglected by loudspeaker designers, especially in the resources devoted to that band. Having enough power and a smooth FR in that band is infinitely more important then whether your system goes below 20 Hz. There are just so many sub optimal designs around it is a scandal. Price is no guide as to whether the speaker is any good or not.

So I would advise you strongly to be many times more concerned about response, and especially the power response above 40 Hz than below it.
That is where the money really needs to go. This sub obsession has set the quality of reproduction for most systems way backwards. A system should sound very good with NO subs, and then a sub just be a little icing on the cake. People really need educating more than ever about the FR range to put most of their financial resources in the optimal place. Things have really gone adrift over the last 20 years or so.

Just to clarify, since I am starting this build from scratch, I want to ensure the system is physically capable of extending down to 5 Hz. I know most LFE tracks rarely drop below 10–12 Hz, but I want that ultra-low headroom built into the design from day one.
I am completely open to your suggestion of increasing the enclosure size. Because these boxes haven't been built yet, going larger will only cost me an extra sheet or two of the 3/4" Baltic Birch veneer plywood I plan to use.

Enclosure Volume & Driver Mechanics
While I noticed the higher output gains offered by the 8.2 ft³ box, I also see that it increases driver excursion. I am trying to determine how critical this is for a 5Hz-capable system. Moving from the 6.2 ft³ box to the 8.2 ft³ box bumps the Xmax by 3.5mm—bringing it to 26.5mm, which is getting uncomfortably close to the driver's 29mm limit. That said, I appreciate that the larger air volume is easier on the driver, creates less voice coil heat under heavy loads, and yields a deeper, more natural bass.
On this note, I have two specific technical questions:

1. Xmax Specifications: Can you clarify how you calculated a 34mm Xmax, compared to the manufacturer’s listed 29mm spec? I am trying to understand that discrepancy.
2. Mid-Bass Impact: How will transitioning from a 6.2 ft³ to an 8.2 ft³ enclosure affect the "punchy" mid-bass frequencies from 40 Hz and up? Will the punch increase, decrease, or remain relatively unchanged?

Cabinet Dimensions & Construction
For construction, my original plan was a 24" x 24" x 24" cube featuring a double-thick front baffle, a central window brace, extensive interlocking bracing throughout, and a dedicated support ring for the driver basket. I will absolutely post build photos once sawdust starts flying!
If I move to the 8.2 ft³ net volume, I will spec the gross internal volume to 8.6 ft³ to account for the 0.4 ft³ displacement of the driver and bracing.

• A 26" x 26" x 26" cube achieves this, but I am wondering if it would be structurally superior to keep the face at 24" x 24" and extend the depth to 31" instead?
• Changing the depth to 31" would actually fit significantly better in my dedicated room layout.

Current System Layout
For context, here is the rest of the audio chain I am integrating these into:

• Receiver: Anthem MRX 1140
• Front L/R: Paradigm Premier 8000F
• Center: Paradigm Premier 600C
• Side Surrounds: Paradigm Monitor 7 v5
• Rear Surrounds: Paradigm Monitor 11
• Atmos: 4x Paradigm Pro PR-80R (In-Ceiling)
• DSP: MiniDSP Flex HTx
• Subwoofers: 4x Sealed FTW-21 drivers
• Amplification: CVR D1004 rack amplifier (capable of 1700W RMS @ 4 ohms, dialed back to 1200W)

 

[Allen Vos]

The supplied microphone in the ARC kit for ARC tuning.

The REW measurements were done with a UMIK-1. I start my measurements at 10Hz only though. The data starts at ~12.5Hz because there is a delay in the PC's audio system. But that's generally below where I'm concerned about trying to tune anyways.




Yes. The lowest correction point in ARC is 15Hz.

I checked my ARC file for that particular room and correction tuning. That sub is using a 15Hz correction setting and a 3rd order roll-off beyond that. It does look like the roll-off below 15Hz is about that but I cannot be entirely certain and it could just be coincidence that the natural roll off of the driver is similar (It's a JL Fathom).

I suspect that the roll-off doesn't apply because in my other system, I use a much higher correction point for that sub and a much steeper roll-off and then let the sub/system do what it does below. The REW measurements clearly show output coming back up after the roll-off point and null it's rolling off into. (If you're curious to see those measurements and the ARC settings for that, you can view them here: https://forums.audioholics.com/forums/threads/living-room-system.128281/post-1687258 )

Also, the above tuning was done on my MRX-540 8k. The REW measurements post tuning also show output down to the same ~12.5Hz point.

OK, so its really looking like all the Anthem reciever/amps will still pass through any signal lower than 15 hz regardless of having ARC correction on or off, and does not utilize any sort of hard cut method, which is good

Im also glad to see the UMIK-1 mic, while it may not be 100% accurate below 20 hz, will still show 5-10 hz for at least the purpose of seeing if an Amp/reciever will pass through lower frequncies.

 

[Allen Vos]

Bigger boxes for ported design or still sealed? You got better results by upping the volume when modeling? What about actual internal volume with bracing, driver, etc?

Definetley sealed drivers. I used Winisd and set output at 1200 watts with both a 6.2 and 8.2 cu box size

Yes output was a bit higher proving the 8.2 cu box is a more effecient size.

Check out my responce to TLS Guy. It has details of the box build

 

[m. zillch]

I know most LFE tracks rarely drop below 10–12 Hz, but I want that ultra-low headroom built into the design from day one.

"10-12Hz"? After analyzing 10's of thousands of movies the people with a focus on infrasonics have located just a handful that technically have some appreciable content below 20Hz (although often what they think it comes from is actually incorrect).

 

[m. zillch]

Percentage of professional commercial cinemas in the US, including THX and Atmos certified, with subwoofers capable of appreciable output below 20Hz: 0%

Of course to cater to the "Mines bigger than yours" market there are home subwoofers that supposedly go even as large as 80 or 100", however the way real deal commercial cinemas approach high output is multiple 18" drivers clustered together to take advantage of a principle called acoustic coupling and they are often mounted just below the screen and slightly off center (so the wall slap reflection from the left wall and right wall will differ rather than reinforce each other)..

In a Dolby Atmos theater, for example, you might be hearing a cluster of these 18" drivers:

 

[Allen Vos]

"10-12Hz"? After analyzing 10's of thousands of movies the people with a focus on infrasonics have located just a handful that technically have some appreciable content below 20Hz (although often what they think it comes from is actually incorrect).

That 10–12 Hz comment was specifically about the legendary, couch-shaking, system-melting movie tracks mentioned earlier in this thread—like Edge of Tomorrow and War of the Worlds. I promise I am not crazy enough to think Peppa Pig or The Notebook has ultra-low frequency bass that drops to single digits.
Man, you guys are like sharks smelling a drop of blood in the water. Remind me never to misplace a decimal point around here, or I might get banned from bass forever!

 

[m. zillch]

That 10–12 Hz comment was specifically about the legendary, couch-shaking, system-melting movie tracks mentioned earlier in this thread—like Edge of Tomorrow

You mean the early releases before they realized they f'd up. . . . so they filtered away the sonically detrimental infrasonics for the subsequent releases to correct their blunder? Nor heard squat from in their own, professional production rooms in the first place? . . . And which now two fellow forum members have indicated they experienced no difference with the newer release UHD filtered version during that critical moment?

One:

. . . it most certainly still has an absurdly deep bass tone going off that is only felt or heard by the walks of the basement creaking and cracking. I've found no difference at all between the BR content and the UHD's.

Two:

I bought the UHD and felt it was identical also.

Sure, maybe the only reason they couldn't notice a difference is because they don't own 100" subwoofers. Or because what you really need is a either a 200" subwoofer or a cluster of more compact ones, but isn't a simpler explanation that what I wrote here is actually correct?

That opening note is deceptive though because exactly when the loud infrasonic tone hits so does a non-controversial loud bass tone around 30Hz !
View attachment 80036

And sure enough, after I wrote this we were shown that full length movie spectral plots indicated that 30Hz tone I specifically warned about was indeed still intact in the later releases:

 

[dolynick]

And sure enough after I wrote this we were shown that full length movie spectral plots indicated that 30Hz tone I specifically warned about was indeed still intact in the later releases:

The explanation for that is simple enough. The new vs old graphs don't show that very low stuff is completely gone, just not as boosted as the first. There would still be that deep rumble and if the system isn't capable of producing it at full intensity anyways, the difference probably isn't that noticeable. In a system with a sub more like the one the OP is constructing, it would probably be much more noticeable.

 

[Allen Vos]

You mean the early releases before they realized they f'd up. . . . so they filtered away the sonically detrimental infrasonics for the subsequent releases to correct their blunder? Nor heard squat from in their own, professional production rooms in the first place? . . . And which now two fellow forum members have indicated they experienced no difference with the newer release UHD filtered version during that critical moment?

One:


Two:

Sure, maybe the only reason they couldn't notice a difference is because they don't own 100" subwoofers. Or because what you really need is a either a 200" subwoofer or a cluster of more compact ones, but isn't a simpler explanation that what I wrote here is actually correct?

And sure enough, after I wrote this we were shown that full length movie spectral plots indicated that 30Hz tone I specifically warned about was indeed still intact in the later releases:

We are beating a dead horse and going in circles. I honestly do not understand the pushback against building a 5Hz-capable system. I have been perfectly clear about my goals, and I should not have to keep reiterating myself: while I will rarely use frequencies that low, I am building this from scratch and want that capability available. Continuing this loop is not productive. Everyone has said their piece, and I am done arguing over opinions.

 

[m. zillch]

The explanation for that is simple enough. The new vs old graphs don't show that very low stuff is completely gone, just not as boosted as the first.

They're effectively gone from human perception.

 

[m. zillch]

View attachment 80033

 

[dolynick]

We are beating a dead horse and going in circles. I honestly do not understand the pushback against building a 5Hz-capable system. I have been perfectly clear about my goals, and I should not have to keep reiterating myself: while I will rarely use frequencies that low, I am building this from scratch and want that capability available. Continuing this loop is not productive. Everyone has said their piece, and I am done arguing over opinions.

If this is what you want to pursue you should. Whether it works out or not, this is a hobby and the pursuit and journey is the point.

There are clearly some here who cannot get out of their own way and forcing their own preference or agenda into every subject. I mostly just ignore them at this point. They also post as though they have any authority over your actual experience or enjoyment of whatever it is that you do hear or feel. There is value in the science and objectivist analysis of things, but ultimately this is a hobby that boils down to your personaly sensory perception of things and whether or not you enjoy it or not.

 

[m. zillch]

If this is what you want to pursue you should. Whether it works out or not, this is a hobby and the pursuit and journey is the point.

Considering infrasonic subs are free, easy to construct, and take up no space I guess that makes sense.

 

[William Lemmerhirt]

You mean the early releases before they realized they f'd up. . . . so they filtered away the sonically detrimental infrasonics for the subsequent releases to correct their blunder? Nor heard squat from in their own, professional production rooms in the first place? . . . And which now two fellow forum members have indicated they experienced no difference with the newer release UHD filtered version during that critical moment?

One:


Two:

Sure, maybe the only reason they couldn't notice a difference is because they don't own 100" subwoofers. Or because what you really need is a either a 200" subwoofer or a cluster of more compact ones, but isn't a simpler explanation that what I wrote here is actually correct?

And sure enough, after I wrote this we were shown that full length movie spectral plots indicated that 30Hz tone I specifically warned about was indeed still intact in the later releases:

I was talking about the square wave. Not the 30hz.