Room size & Rythmik subs.....

[randyrlee2]

Hey everybody,

Recently set up my first 5.1 HT, with my RAAL Towers, Horizon center, and Luna surrounds. I had a couple of Velodyne 10" subs from a previous stereo setup and threw them into the HT system. I have had them go beyond their ability, sounds a lot like clipping in a regular speaker.

Room size = a recently opened up my basement where I took out doors and walls. Concrete floor with pad and carpet over all. The whole volume is about 6000 cubic feet. Emailed Enrico at Rythmik and he said I would need dual FV18 subs. That is more than I want to spend, and more area than I want to take up with subwoofers. Those things are HUGE!

I can live with dual FV15HP's, but don't want to get them if I needed to upgrade later. What are your ideas? I have lurked and know some of you folks are really, really knowledgeable about this topic.

Thanks in advance.

randy

[davef]

Hey everybody,

Recently set up my first 5.1 HT, with my RAAL Towers, Horizon center, and Luna surrounds. I had a couple of Velodyne 10" subs from a previous stereo setup and threw them into the HT system. I have had them go beyond their ability, sounds a lot like clipping in a regular speaker.

Room size = a recently opened up my basement where I took out doors and walls. Concrete floor with pad and carpet over all. The whole volume is about 6000 cubic feet. Emailed Enrico at Rythmik and he said I would need dual FV18 subs. That is more than I want to spend, and more area than I want to take up with subwoofers. Those things are HUGE!

I can live with dual FV15HP's, but don't want to get them if I needed to upgrade later. What are your ideas? I have lurked and know some of you folks are really, really knowledgeable about this topic.

Thanks in advance.

randy

Hi Randy,

Dual FV15HP subs will be more than fine for your space. You definitely do not need dual 18's. Just this week I heard form a customer of ours who is using dual FV15's in a room that is close to 10K cu ft and he commented that they are perfect for the space....

[N Boros]

To help further ease your concerns about the FV15HPs in your room size, Audioholics reviewed the subwoofer years ago and rated it Bassaholic Extreme, which means that it is suited to room larger than 5000 cubic feet.

https://www.audioholics.com/subwoofer-reviews/hsu-vtf-2-mk5/Audioholics%20Bassaholic%20compilation-111016.pdf

https://www.audioholics.com/loudspeaker-design/subwoofer-room-size

[randyrlee2]

Thank you Dave and N Boros. That's exactly what I needed to know.

It's really nice to have a place to go like this forum where folks with the same stuff as me have experience and are willing to share.

Again, thank you! randy

[Bruce Watson]

Room size = a recently opened up my basement where I took out doors and walls. Concrete floor with pad and carpet over all. The whole volume is about 6000 cubic feet. Emailed Enrico at Rythmik and he said I would need dual FV18 subs. That is more than I want to spend, and more area than I want to take up with subwoofers. Those things are HUGE! I can live with dual FV15HP's, but don't want to get them if I needed to upgrade later. What are your ideas?

Enrico is a good guy, knowledgeable and honest AFAIK. But I suspect he's giving you the worst case scenario -- that is, that you want to produce reference audio (https://www.acousticfrontiers.com/2013314thx-reference-level/) by the book, which means you need sufficient power at 20 Hz to get to around 115-130 dB (depending on which of several theories you believe) because of the Robinson-Dadson equal loudness contours (https://en.wikipedia.org/wiki/Equal-loudness_contour). The power required to do this goes up exponentially with frequency; pressurizing 6k cuft of air at 20 Hz is... difficult. Thus his recommendation of the FV18s.

But... who actually listens at reference levels in a house? Granted, there are people who do. But are you one of those people?

I personally have a sealed room with less than half your volume (and Sierra 2s across the front, Sierra 1s for surround, and a pair of LVX12s subs), and the maximum I normally listen to, even when my wife is out of the house, is around -17.5 dB. Well less than reference, and therefore needing much less from my subs (which still do an admirable job of shaking the walls, couch, doors, etc.).

If it were me, I'd be perfectly happy with a pair of FV15HPs in a room that size. But I'm not you, and I have no idea what you actually want to do. I suggest that rather than emailing Enrico (or Dave for that matter) I'd pick up the phone and call. Have a conversation, answer their questions, and get a reply customized for your room and your needs. Just sayin'.

[white_darren]

But... who actually listens at reference levels in a house? Granted, there are people who do. But are you one of those people?

This is a key consideration.

I am not one to listen at reference levels and I am quite happy with a single E15HP in a space of about 20,000 cu ft. I also lucked out and didn't have any major room integration issues with the single sub (courtesy a large, irregular shaped room with open corners).

[randyrlee2]

Thanks everyone for your input. Very much appreciated.

Don't think I need reference level (if that's incredibly loud) anything. I've actually never heard a good or loud (or actually any other) home theater setup, so I'm just trying to get it done close to right. Ordered one FV15HP to start, and will go from there. Did look at the journal article showing two subs were good and best placement.

Am going to set up the sub per Rythmik's recommendation to start.

Do I need to get an SPL meter and test my room when I get the sub? Is there a reference where I can see what I need to do, or how to test if so?

Thanks again for your help.

[Mahawkma]

Hi,

Assuming that you will be running some kind of room EQ using a receiver, check out this guide from AVSForum on how to dial in Rythmik subs (http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1214550-official-rythmik-audio-subwoofer-thread-538.html#post25314641). I used it when I put in my new F12s. Just did the basics as I don't have a sound meter nor a mike to run REW and got what sounds like good results to my ears. :)

Thanks,

Hawk

[Mag_Neato]

Hi Ascend community,

I have a similar question for my new home theater. The Great room is roughly 3400 cu/ft (The vaulted ceiling makes it really "fun" to try calculating), and is open floor plan, concrete slab with hardwood floors. I had the builder's media guy wire and install a 7.2 setup for ATMOS using in wall speakers front L/C/R, ceiling L/R, and rear L/R. There are two sub hookups in the wall on either side of the TV. Receiver is a DENON X3300 with Audyssey XT32 so it will calibrate and EQ dual subs.

My budget will be about $1K give or take. Was considering dual LV12R's thinking a ported design will give better output to compensate for the open floor plan.

Thoughts/comments/concerns?

[goldark]

Hi Ascend community,

I have a similar question for my new home theater. The Great room is roughly 3400 cu/ft (The vaulted ceiling makes it really "fun" to try calculating), and is open floor plan, concrete slab with hardwood floors. I had the builder's media guy wire and install a 7.2 setup for ATMOS using in wall speakers front L/C/R, ceiling L/R, and rear L/R. There are two sub hookups in the wall on either side of the TV. Receiver is a DENON X3300 with Audyssey XT32 so it will calibrate and EQ dual subs.

My budget will be about $1K give or take. Was considering dual LV12R's thinking a ported design will give better output to compensate for the open floor plan.

Thoughts/comments/concerns?

Let's do some math.

At 3400 cubic feet, you're around a medium/larger room, going by Audioholics subwoofer room guide: https://www.audioholics.com/loudspeaker-design/subwoofer-room-size

They recommend your subwoofer be able to output 103 dB at 25 Hz and 109 dB at 31.5 to 63 Hz for a medium room, and 109 dB/115 dB in a large room. Let's split the difference for your room and set your output goals at 106/112 dB, respectively.

1 FV15HP in 2 port mode can output 113 dB at 25 Hz and averages about 118 dB from 31.5 to 63 Hz by itself: https://data-bass.com/systems

A single LV12R is down about 8 dB in max output from the FV15HP: http://www.rythmikaudio.com/products1.html

The LV12R would give you about 105 dB at 25 Hz and an average of about 110 dB from 31.5 to 63 Hz. 105/110 is just shy of our target output of 106/112. However, adding a second LV12R can add anywhere from 3-6 dB in your room depending on location across the spectrum and has the added bonus of evening out bass response, so you should be fine. All the above assumptions are if you like to listen to near reference volumes as well.

If you listen to more reasonable levels, you are more than fine with dual LV12R in your room.

[Bruce Watson]

I have a similar question for my new home theater. The Great room is roughly 3400 cu/ft (The vaulted ceiling makes it really "fun" to try calculating), and is open floor plan...

When people say "open floor plan" that worries me. To calculate the air volume that the subs are working into, you need the volume out to solid floor-to-ceiling walls in all directions. Out to a couch the defines the boundary between the great room and the next room over isn't sufficient. IOW, the air volume your sub(s) have to work into might actually be far greater -- it might be the entire floor of the open floor plan house that the great room is part of.

In general, the bigger the air volume, the more work the subs have to do to produce the same levels. So bigger air volumes imply bigger drivers, or more drivers.

I can guess (and it's only a guess) that a room that size is going to be a challenge for a sub that small. That said, much depends on what you're listening to, and how loudly you want to play it. Also, how low you want to go. For example, if you're really interested in playing a movie like Ready Player One at reference volume (master volume at 0 dB), and you want to feel all the sub-sonics down to, say, 10 Hz, then the entry level LV12R, or even a pair, isn't going to prove satisfactory. Won't play loud enough, or reach deep enough.

If OTOH, you're more interested in playing Mozart's Piano Concerto #23 while you eat dinner (much quieter than the Ready Player One demo, and the lowest note on a modern 88 key piano is 27.5 Hz IIRC, and Mozart's keyboards didn't go that low), then one or a pair of LV12Rs might work out just fine.

[Mag_Neato]

A few pics of the room/house:

[Mag_Neato]

To comment on Bruce's concerns:

I do not usually listen at or near reference level. The system will be mainly for HT with maybe some occasional music as background noise, but not for critical listening.

[goldark]

You should be fine then. Seems like your room isn't completely open to the kitchen, only half of it is? That should provide extra bass reenforcement than if it was completely open.

Lower bass frequencies (<20 Hz) can only be experienced fully at higher output levels because it takes higher volumes to perceive low bass compared to higher frequencies. At your lower listening levels, a high output sub that can dig well below 20 Hz isn't being used to its full potential anyway.

[Mag_Neato]

Thanks to all who provided feedback.

After speaking with Ascend, I decided to order two of the LV12R's, which are actually discontinued to make way for the LV12F.....front ported version. As the official units are a few months off, I picked up the discounted preliminary units they had available. These, I was told, use the components from the "old" LV12R in the new front ported cabinet, where the new LV12F will use new components. Rythmik says there will be only a slight difference in performance.

When I say "Ascend" I am referring to Dina. She's awesome!

[goldark]

Thanks to all who provided feedback.

After speaking with Ascend, I decided to order two of the LV12R's, which are actually discontinued to make way for the LV12F.....front ported version. As the official units are a few months off, I picked up the discounted preliminary units they had available. These, I was told, use the components from the "old" LV12R in the new front ported cabinet, where the new LV12F will use new components. Rythmik says there will be only a slight difference in performance.

When I say "Ascend" I am referring to Dina. She's awesome!

Interesting. Any reason why they're moving to the LV12F with only a "slight difference in performance?"

[Mag_Neato]

Interesting. Any reason why they're moving to the LV12F with only a "slight difference in performance?"

My understanding is that customers unanimously requested a front ported design. The component swap may just be due to availability, or unavailability of the old parts.

[racrawford65]

When I say "Ascend" I am referring to Dina. She's awesome!

+1 for Dina :-)

[Mag_Neato]

So, a little update:

Received the dual LV12F's on Thursday. Placed them in their designated, non-scientifically chosen locations to either side of the media console on the front wall. Bass extension set to low. Crossovers for L/C/R & rear surrounds at 80Hz, in-ceiling speakers at 60Hz.

I ran Audyssey XT32 to get everything dialed in. I do not have REW or anything to measure the room, nor do I own a laptop to try it, so I'm only going by my ears.

The overall sound is smooth, clear and balanced. Bass not overpowering but rather controlled. It does not say "Hey, look what I can do", but rather blends in as an extension of the speakers. When watching Avengers: Infinity War on 4K Blu-ray in ATMOS the bass will make the explosions explode, and the big alien machinery will shake the room. I did not detect any strain and it sounded dynamic. I am very pleased with the system! The room is large and open to the kitchen/dining/foyer, etc. so there's a lot of volume to fill, and the dual subs handle it well.

[Fast351]

I realize that you have your situation already sorted out, but I figured I'd add this for people that are reading this thread in the same predicament....

I have a LARGE theater room. It's 19x39x9, or 6669 CUFT. I have a pair of FV15HPs in there, and let me tell you, it is plenty. When playing music, it sounds beautiful, with a solid foundation of nothing but tight bass.

When watching movies, it's every bit as good as a theater. It gets loud enough that my wife says she can CLEARLY hear it 500' away at the house across the road. :)

Pic for pic's sake: (subs are about 20' from the front wall)

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