Dual Sub Setup for my room - Seeking Advice

[Talley]

So a few details:

Room size: 14.3'W x 20.75'L with sides of room at 8' and peak at 12'. I've measured exactly 3,000cu-ft of space.


I've since placed my homemade rack in the dead center of screen and my center channel sits on it. I have a single HSU VTF-15 mk2 sub and it sits between the center channel and right speaker. There is space for one more sub at the same location but left speaker. Symmetrical.

This is the current room response on my single sub:

The response is with the HSU sub in 1 port open 16hz tune mode. It's dead on at -3db at 16hz and -5db at 14hz but falls off after that. What I'm really chasing is single digits in a reasonable thought out manner. I really want dual subs so I can have stereo subs for music. I can easily get a second VTF-15mk2 for $1086 delivered and that would give me better response and maybe a few db more output but extension will be the same. My goal here is headroom and low distortion. Since I have a single sub I could easily buy a dual sub of another brand. I thought about dual SVS PB-16 Ultras, Dual PSA V3601's, or Dual Rythmik FV25HP. Another idea would be to have dual ULS-15 MK2 subs since they are much smaller and more space friendly but I can work with that. My current subs literally sit about 1" higher than my screen projects. I can move the screen up but it doesn't bother me since I mostly watch movies and most movies are letterbox anyway. The center channel sits inside the screen viewing area for anything 16:9 but again I deal with it... doesn't bother me. I wanted my 135" size screen and so this is what I have to deal with. My projected 16:9 screen bottom is exactly 24" from the floor. Doesn't leave much room to work with. I have to have my room setup like the image. Wife orders. So I deal with certain things like this.

Either way... I thought about just adding the second VTF15mk2 sub for the cost to get me into the dual sub quick.... then later this year say october getting replacements for big and angry.

Any thoughts?

 

[chrapladm]

The easiest way to get more bass from your current setup is to move your sub to the corner. When searching for single digits you are going to need Vd. Or lots of cone area. So a single large ported cabinet could be nice for around 12hz possibly.

If wanting single digits though you will most likely need to rethink your approach.

So as an example needing single digits may require four 18's in dual opposed cabinets with a large amplifier. (DIY setup) BUT if not needing exactly 5hz you could use a pair of ported 18's tuned to about 12hz and be quite happy to 10hz. Then depending on your room possibly happy down to 7hz.

This is all of coarse from a DIY point of view. JTR has some nice subs and so does Seaton.

BUT if you like what you have then more of the same and corner placement may be an easy answer for you.

 

[Tony V.]

Stereo subs for music is a waste of money as anything below 100hz would never be heard in stereo as the wavelength gets too big and becomes nondirectional. Most if not all recordings abandon mixing stereo below around 150hz

 

[Talley]

Have you tried it?....

I’m sure most would agree two is better for one especially for headroom. My issue is I can localize Subs in my room due to the various harmonics of the room vibrations or floor vibrating. Duals keeps everything uniform. Also helps eliminate room modes.

Thanks for your input though.

 

[Hlam]

Four subs are better.
My system is in the living room so no room treatments of any kind allowed. I find that four subs give me great results.
I could never get any benefit with just two. I always got a better response with one sub.
By the way Talley that is a beautiful room you have there.

 

[Tony V.]

I never said multiple subs was not recommended, I just said running them in a stereo configuration was not. Ideally you want to use the sub out if your running a receiver or per/pro setup witch is not stereo

 

[chrapladm]

I never said multiple subs was not recommended, I just said running them in a stereo configuration was not. Ideally you want to use the sub out if your running a receiver or per/pro setup witch is not stereo

And to further add running stereo subs would not normally be useful because wavelength size. BUT as I know Tony knows you can use your subs up to 200hz if lacking in your mains. So having them located under your mains would be helpful.

Four subs are great if you have the room. A single sub is great also if you can only accommodate one. But to help even out the sweet spot or listening area with even bass across multiple seats having more than one subs is most needed.

Four subs in completely different places would be most helpful for room modes. BUT lets get back to OP's wants.

So are you wanting to a OEM sub that is small and under $1000?

And how low do you actually want to reach?

I can hit 5hz just fine in my room but I honestly need a few mores subs to really be able to experience it properly. So just trying to understand exactly what your after.

 

[Tony V.]

Is there many if any movies that really have anything below 10hz, many movies even filter it at 20hz or even higher. As long as you can reach a nice solid 15hz there is no need for deeper.
Tally, you need to look at matching what you currently have for a sub.

 

[Talley]

Tony,

Your right. And honestly adding a second vtf-15 mk2 would be the cheapest route forward. I’ve been really impressed with the single hsu. For the price I paid for the first one and the current sale my total cost would be $2,050 which is a cost effective solution. Would allow me to plays with duals and help me figure out my room more. Find the sweet spots and such.

Also... I’ve already placed my order for the second hsu so I’ll keep y’all informed as to the differences I experience.

I have more to comment later but I’m out right now shopping.

 

[Talley]

Now that I'm at home...

I think in the end I'll end up selling the dual HSU subs and going with dual Rythmik FV25HP subs. I can do a local pickup option for two of them for $4500 but for right now spending 1k to add a second sub is more reasonable. Something about those Rythmiks just turn me on. They will also without a doubt give me more headroom and lower extension. Till then I'll enjoy the HSU until that time comes. I think I'll be able to sell the dual HSU setup for 1400 rather easily then it'll just be a 3100 upgrade cost to the dual rythmiks.

 

[chrapladm]

Is there many if any movies that really have anything below 10hz, many movies even filter it at 20hz or even higher. As long as you can reach a nice solid 15hz there is no need for deeper.
Tally, you need to look at matching what you currently have for a sub.

There are movies out that have plenty of ULF below 15hz. That being said majority of movies do have the ULF filtered out.

When wanting <10hz you also have to have the amp power and electronics that dont roll off at 10hz. So its not as simple as adding a second sub.

I am sure you will be much happier once you have your second subs setup either way.

 

[tesseract]

Chasing single digit FR is fraught with problems, as we can see, not to mention the creaks and groans that will become audible as the house complains loudly. I have experienced a capable dual IB, four 15" Acoustic Elegance drivers per manifold (8 total) system reproduce a high level 5 Hz signal. All I heard was the home sound like it might cave in, lol. We walked it up to 20 Hz and it sounded much cleaner.

Personally, I am happy to get to a clean 16 Hz. Single digit is cool to say you have, but the effort to get there will only be rewarded a small percentage of the time the system is used.

 

[Talley]

Single digits would be nice of course and sure I'd love to chase for just that but that is actually 3rd on the list of my desires. The first two are as I said "My goal here is headroom and low distortion."

What I want is huge dynamics. Either way I think I'm sold on ending up with dual Rythmiks FV25HP's but for now the dual HSU will most likely be ample enough and will make me desire no more.

 

[Talley]

Dual HSU subs are in!!!

What a dramatic difference having two subs are.... wow. So much more impact and they never felt stressed and boy do they really shake the room now. I should of never waited this long. I couldn't imagine more bass than this... these things are scary.

 

[Hlam]

Congrats. Glade the new addition is making you happy.

 

[Hlam]

Not to rain on your parade. But.
The subs seem to be setup more for aesthetics than performance. Do you have any other options for placement. You could be leaving some performance on the table.
On the other hand you are happy with this setup. It may be best to leave well enough alone.
Do not fall into the rabbit hole.
It leads to a lot of moving and measuring. Also could lead to more subs.

 

[Talley]

Not to rain on your parade. But.
The subs seem to be setup more for aesthetics than performance. Do you have any other options for placement. You could be leaving some performance on the table.
On the other hand you are happy with this setup. It may be best to leave well enough alone.
Do not fall into the rabbit hole.
It leads to a lot of moving and measuring. Also could lead to more subs.

No other room for placement. My room is not conventional. Honestly the single sub gave me a really smooth response. Just need to get REW working again so I can see where dual subs put me.

 

[Hlam]

Good luck.
I have a very similar setup.
Two SVS SB13's that are setting under my ascend acoustics sierra 2 bookshelf speakers. The SVS subs replaced a paradigm servo 15.
It is a living room setup so no room treatments and no where else to move the subs. WAF.
Using the sub under the left speaker gave me a very flat response. Adding the second sub in really messed hings up.
Being a typical man I would never admit to my wife that she was right all along and I did not need a second sub.
I left the one under the right speaker turned off for 5 years. LOL.
I added a pair of PSA S1500's to the back of the room and this put me in bass heaven. I went with the PSA's because they were small enough to fit under the end tables.
Hope you have better luck getting your pair to work together than I did.

 

[Todd Anderson]

Dual HSU subs are in!!!

What a dramatic difference having two subs are.... wow. So much more impact and they never felt stressed and boy do they really shake the room now. I should of never waited this long. I couldn't imagine more bass than this... these things are scary.

View attachment 5741

Looking GREAT!

Now it's time to add 2 more and go quad!

 

[Talley]

Looking GREAT!

Now it's time to add 2 more and go quad!

I'll more than likely end up doing just that. I'll just add two more VTF-15's. I've been super pleased with one... barely cranking out the second one but super impressed now. I've never had issues with my screen moving but I can get the screen to shake now with the second added.

The other two would be near field setup on the opposite end one on each end of my sofa. I'd build a custom end table to go over it. This would put me two in corners in the rear of my room and two up front.

For basically $4200 spent for four of these it would be hard to match that. I mean I guess I could go with dual PB-16Ultra for more money but I think the quad setup would be better in the end.

 

[Todd Anderson]

You'll just need to make sure you have the right gear to manage quads (right now in my HT, I'm splitting front and rear dual subs out of two sub outputs and letting Audyssey manage them). You just have to find a way to let your system appropriately set delays and volume.

 

[Talley]

Well I finally got around to testing my stereo subs. One thing I didn't know is when you select the subs as stereo on the XMC-1 then the left channels only use the left sub... the right channels front/rear uses the right sub... the center uses both subs.

I wonder if I should be selecting dual mono option so both subs run together all the time

This chart is just the subwoofer LFE channel so for the LFE they both run together. The blue is the Q.70 setting while the green is the .55 setting. Yes my 73hz null is forever existing... however if I manually select crossover to 50hz on the subs the speakers typically have a really smooth response. The setting of 80hz is a poor choice but I can't seem to figure out how to change this in the Dirac selection on the xmc-1...

 

[tesseract]

I am not sure how, or if it is possible to set the Dirac XO on the XMC-1, would be nice to accomplish. Running dual mono should not matter for localization at frequencies below 80 Hz, especially if the slope is 4th order. If it can help with the null, go for it. The null is pretty narrow, so audibility is minimized.

 

[Talley]

I am not sure how, or if it is possible to set the Dirac XO on the XMC-1, would be nice to accomplish. Running dual mono should not matter for localization at frequencies below 80 Hz, especially if the slope is 4th order. If it can help with the bill, go for it. The null is pretty narrow, so audibility is minimized.

That 73hz is a pain in the rear frequency for my room. No matter where the sub is located it's there. I found only one place where the sub removed that and it was middle of the room in front of the left main. Can't really put it there though.

Crossing over at 50hz eliminates it with audessy but I no longer use the x4300... it sits in a box ever since I put the xmc-1.

Dual mono should give a bit more output since each sub would be matched in output... the output should be a bit higher. I'll have to play with it.

 

[Tony V.]

That 73hz dip would be almost impossible to hear, your annualizing the issue too much.