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Rythmik E15 vs HSU ULS-15 MK2 / VTF-3 MK5 for below 20hz feel in large room.

geek101

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optimizing for size Rythmik E15 seems like a choice to have a subwoofer than play below 20hz as Rythmik claims -2db @ 14hz. But as the plot shows it is not +/- 14hz to 150hz etc. no CEA numbers either so I am a bit confused. What does -2db at 14 hz mean here ?.

I am targeting a sub that go below 20hz when placed in a corner and provide the infrasonic goosebumps for movies etc.

The space is large around 5000 cubic ft. But seating is not more than 2 meters from the sub. And folks don’t listen at reference level so it is ok to be -3 to -6db down.

HSU subs have specs listed clearly , FR curves and CEA measurements are on the website.

I could go for HSU ULS-15 MK2. It is small and two of them in same space becomes less harder sell later.

Or is that HSU VTF-3 MK5 is the only viable path to get decent levels @ 16hz in room?.

Any one has experience with either of these subs ?.

I understand that at 20hz and below 3db difference is perceived twice as loud. And HSU VTF MK5 is twice as loud as HSU ULS-15 MK2 for peaks.
 

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Why not the HSU VTF-TN1 Subwoofer
  • Compared to other HSU subs:
    • Larger enclosure than the VTF-3 MK5 HP, so more efficient in the deeper bass
    • Larger ports at a lower tuning than the VTF-3 MK5 HP, so it not only plays louder and cleaner with sub 20 Hz bass (less port noise), but also plays lower
    • Plays significantly louder and cleaner than the VTF-2 MK5 across the board (like having two of the VTF-2 MK5’s put together) with low distortion.
    • Plays significantly louder and cleaner than the ULS-15 MK2 in the deeper bass (like having two ULS-15 MK2’s put together) with low distortion.
    • Among the smallest footprint - similar to the ULS-15 MK2.
It reaches 111db @16Hz according to HSU. If only I could get these subs in Europe...

HSU sub.png
 
Why not the HSU VTF-TN1 Subwoofer
  • Compared to other HSU subs:
    • Larger enclosure than the VTF-3 MK5 HP, so more efficient in the deeper bass
    • Larger ports at a lower tuning than the VTF-3 MK5 HP, so it not only plays louder and cleaner with sub 20 Hz bass (less port noise), but also plays lower
    • Plays significantly louder and cleaner than the VTF-2 MK5 across the board (like having two of the VTF-2 MK5’s put together) with low distortion.
    • Plays significantly louder and cleaner than the ULS-15 MK2 in the deeper bass (like having two ULS-15 MK2’s put together) with low distortion.
    • Among the smallest footprint - similar to the ULS-15 MK2.
It reaches 111db @16Hz according to HSU. If only I could get these subs in Europe...

View attachment 398517
It’s seems it is too large !!. It’s tall enough to draw attention
 
Do you want real loud deep bass or not?

Put a plant on it.
 
Plus if you're near So Cal you can pick the Hsu up and avoid shipping.
 
The TN1 would be my suggestion as well for subs that have published data. I've had both the ULS-15 and VTF 3.5 plus about 25 different subs over the years. If you're looking for a one sub solution you'll have to stick with ported unless your budget can handle something like the JTR RS1.

I personally would look at the Power Sound Audio TV21neo-M or TV1813-M. I had an EV1813-M and it was the best single sub I've ever had.
https://www.powersoundaudio.com/collections/subwoofers/products/tv21neo-m

 

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Do they have a demo room ?
Not sure but I believe they do. Too far for me, haven’t been there. But they’re right off the 91 fwy.
 
Plus if you're near So Cal you can pick the Hsu up and avoid shipping.
I don’t think I will be able to load and unload to/from the car myself . Kind of a road trip for me too, I do like idea of demoing all three models before buying
 
If both are in your price range, I would not hesitate to pick the Rythmik. Ignore any technical data or response chart that will not tell you what the room does to your sub and except that in times of DSP'S you can make any woofer look good on paper.
A servo controlled sub goes deeper and will deliver a much more pronounced bass than a "normal" woofer, just equalized by a DSP. The Rythmik is a real servo system, with a dedicated sensor coil. It's distortion will be a magnitude lower than a that of a conventional driven sub.
The only problem, once you had such a sub in your system, you will never want a conventional one again.
You may ask why there are not more servo systems on the market. Simple answer, as long as the customer buy's "bum-bum" bass, there is no need for a more expensive, special chassis and a control circuit. If you want to know more, look for MFB = Motional Feed Back.
A bonus, Rythmik sells kit's too, which may save a reasonable amount and gives you the option to match it to your taste.
 
If both are in your price range, I would not hesitate to pick the Rythmik. Ignore any technical data or response chart that will not tell you what the room does to your sub and except that in times of DSP'S you can make any woofer look good on paper.

That’s very silly. The room will do effectively the same thing to any sub placed in the same spot. Extra and unnecessary electronic complications don’t play a role in that.

A servo controlled sub goes deeper and will deliver a much more pronounced bass than a "normal" woofer, just equalized by a DSP.

What leads you to that (erroneous) conclusion?

The only problem, once you had such a sub in your system, you will never want a conventional one again.

Bravado is not argument.
 
If both are in your price range, I would not hesitate to pick the Rythmik. Ignore any technical data or response chart that will not tell you what the room does to your sub and except that in times of DSP'S you can make any woofer look good on paper.
A servo controlled sub goes deeper and will deliver a much more pronounced bass than a "normal" woofer, just equalized by a DSP. The Rythmik is a real servo system, with a dedicated sensor coil. It's distortion will be a magnitude lower than a that of a conventional driven sub.
The only problem, once you had such a sub in your system, you will never want a conventional one again.
You may ask why there are not more servo systems on the market. Simple answer, as long as the customer buy's "bum-bum" bass, there is no need for a more expensive, special chassis and a control circuit. If you want to know more, look for MFB = Motional Feed Back.
A bonus, Rythmik sells kit's too, which may save a reasonable amount and gives you the option to match it to your taste.
Rythmik subs do have low distortion but seems like other brands also match them closely. I like the low distortion of Rythmik F18 as tested by data-base.com . I wish third party tests are available for Rythmik E15 so I can compare against HSU 15” subs.
 
What leads you to that (erroneous) conclusion?

Many years of experience with MFB or servo controlled subs. Maybe you should listen to one or two before making insulting replies or at least try to understand how this works and what the results are.
 
room does\will do
the same thing to any sub placed in the same spot. In room responce consists of room transfer function and anechoic subwoofer response. Which frequency response can be different. For example 0 dB\oct for idealised acceleration feedback or 12 dB\oct for textbook sealed box or 6 dB\oct for Q=0.0.. :) sealed box etc.
1729930135969.png

- this is [calculated] anechoic responce of of my subwoofer; in the room they are used without any equalization at all.
 
Got the HSU VTF-TN1 after some consideration. Will be integrating them with Kali in8 v2 using a Denon AVR. Will post REW in room measurements soon. View attachment 403249
Did you consider the Kali WS-12? Was it the fact their spec does not show them going as low as the Hsu or Rythmik? Please comment in some detail.

I am running a pair of Kali in8 v2 in my second system.

BTW I knew Dr. Hsu when we both were in grad school, but Rythmik is closer to me now.
 
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Did you consider the Kali WS-12? Was it the fact their spec does not show them going as low as the Hsu or Rythmik? Please comment in some detail.

I am running a pair of Kali in8 v2 in my second system.

BTW I knew Dr. Hsu when we both were in grad school, but Rythmik is closer to me now.
The space is large like 5000 cubic ft but seating distance for front speakers is 9ft and sub will be in a corner 16ft away.

I went for a sub that has meaningful output at 20hz and below. loud enough for home theater use. With measurements available, reviewed by 3rd part with measurements. Low floor foot print. Good looking with good finish. And cost effective. I personally do not think there is anything in the market which can compete with this sub give the above considerations.

oh wow very cool that you knew Dr Hsu personally was that at MIT?. Tough place too.

Rythmik ported 15” was under my radar but just too larger for where I am setting up this sub.

Personally I may just go for JTR RS1.
 
@geek101, I'm considering a '30Hz and lower woofer' to supplement a single WS-12 in the In8 v2 system. The ws-12 is presently between the IN8s. This room is about the same cubic size as yours. I'd place the '<30Hzer' perhaps in an opposite corner behind the listening position. Considering using the internal woofer low pass only. Any ideas about my options and choices?
 
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@geek101, I'm considering a '30Hz and lower woofer' to supplement a single WS-12 in the In8 v2 system. The ws-12 is presently between the IN8s. This room is about the same cubic size as yours. I'd place the '<30Hzer' perhaps in an opposite corner behind the listening position. Considering using the internal woofer low pass only. Any ideas about my options and choices?
I think mixing subs of different makes is more tricky ?. Do you have Minidsp etc ?

Try REW simulator to find out few ideal spots ?
 
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