RBH Sound 21" Monster 4kwatt Sub First to Meet our Maximus Bassaholic Rating!

[gene]

RBH Sound’s Unrivaled 21-SF/R is a 300+ lbs. monster that uses a 21” carbon fiber driver powered by a 4,000 watt amplifier. This bruiser is so powerful that it forced us to create a whole new category of performance for our Bassaholics room rating called Maximus. This 21” behemoth uses a carbon fiber cone that attaches to a massive cast aluminum basket with a correspondingly large half-roll rubber surround. It has a staggering 38mm of Xmax (one-way linear travel) and 50mm of Xmech (one-way mechanically limited travel). The motor uses eight neodymium slugs for the magnet since iron ferrite would have been too large and heavy to support within the enclosure. Even though neodymium is very expensive, RBH did not want to compromise on their performance targets for the 21-SF/R, and the resultant magnetic flux is tremendously powerful at 35 Tesla Meters.

I just got this beast integrated into my theater room and getting flat 10Hz in-room bass response with little boost needed. I am literally measuring bass down to the limit of my microphone (5Hz).

Read: RBH Sound 21-SF/R 4kWatt Subwoofer Overview

Note: This is the official thread for the RBH 21-SF/R subwoofer and I will be showing measurements and linking up the formal review once completed. Bassaholics will want to bookmark this thread.

 

[isolar8001]

Holy Moly !!!
Mold broken....new standard achieved. This sure doesn't happen very often.

 

[Danzilla31]

Gene rocking it with the shades!!!!

You know you were feeling badass sir sitting there with that sexy beast.

When I say sexy beast I was talking about you not the subwoofer

 

[kini]

For that price I would much rather go with Funk or Harbottle.

 

[corey]

So, along with your recent article on WaveForming, I guess the correct way to go would be 5 of these, hung on the walls.

 

[vader540is]

For that price I would much rather go with Funk or Harbottle.

I agree.

 

[gene]

For that price I would much rather go with Funk or Harbottle.

And for the price of those I'm sure someone would rather go with another brand

For that price I would much rather go with Funk or Harbottle.

I'm sure you would. and someone else that hasn't heard any of these subs would want to go with another brand they also never heard before too

 

[Trell]

Not easy to move an 151 kg subwoofer around.

 

[Mr._Clark]

Gene, do you know why RBH decided on a sealed design?

My question is not meant to imply that this was the "wrong" choice. I'm just interested in learning about the factors that go into a design like this.

 

[ryanosaur]

RBH is well regarded for many of their upper tier product. In a way I'm surprised that they committed to a 21" product, but this is becoming territory that is sought after by more and more people. Granted, a majority of them are falling into the category of using Pro Drivers in Flat Pack kits.
I am very interested to see how the numbers stack up for this Sub. I have little doubt that it will measure very well and stand up to scrutiny as that is pretty much expected for a product in this class.

Gene, do you know why RBH decided on a sealed design?

I'm certain he may have more info to share, but there are many Drivers on the market that are designed specifically for smaller Sealed enclosures with ample Voltage applied through a very capable Amp. Likewise, the companies which are building finished product are also facing that same market...
While larger cabinets both Ported and Sealed make sense, the simple fact remains that space is always at a premium in any HT and many folk are putting 3-8 Subs into their rooms.
(Mind, I'm not making a judgement here on the choice of quantity, however there are many who will say that the more Subs you have chugging along buys you greater ability to quash room modes and boost SPL to the levels they want with +10 Subwoofer House Curves and the like. And there are many! who are into this. Again... not staking out a claim that this is the best choice... just reporting on the people doing it. )

 

[Verdinut]

I'm not impressed at all with this driver which sells at $10K. Expensive to buy and expensive to drive! You need an extra 20 amp 240 volt circuit to use it.

I can get 20 Hz at -3dB without any boosting with each of my Dayton RSS390-HF4 subs while this one gets down to that frequency at -7dB. Moreover, I don't need massive amplifier power because my subs are ported.

 

[AcuDefTechGuy]

First, I love the name “Maximus Bassaholic” - definitely sounds serious bada$$.

2nd, as with anything else, there is a subwoofer for everyone. If you own a bada$$ RBH SVTRS system, and somehow you still desire (definitely not Need) another subwoofer, then naturally you’ll probably want a RBH 21” Maximus Bassaholic subwoofer monster.

But there is a system for everyone.

 

[gene]

Gene, do you know why RBH decided on a sealed design?

My question is not meant to imply that this was the "wrong" choice. I'm just interested in learning about the factors that go into a design like this.

There are many advantages to sealed vs ported for large high output, high excursion subs. The room gain for infrasonic bass in a sealed sub is superior compared to the ported sub below tuning. They will be offering a ported version but the enclosure is massive and I wouldn't put that in my theater room

 

[gene]

First, I love the name “Maximus Bassaholic” - definitely sounds serious bada$$.

2nd, as with anything else, there is a subwoofer for everyone. If you own a bada$$ RBH SVTRS system, and somehow you still desire (definitely not Need) another subwoofer, then naturally you’ll probably want a RBH 21” Maximus Bassaholic subwoofer monster.

But there is a system for everyone.

I absolutely don't need this sub but I definitely want it

 

[gene]

I'm not impressed at all with this driver which sells at $10K. Expensive to buy and expensive to drive! You need an extra 20 amp 240 volt circuit to use it.

I can get 20 Hz at -3dB without any boosting with each of my Dayton RSS390-HF4 subs while this one gets down to that frequency at -7dB. Moreover, I don't need massive amplifier power because my subs are ported.

The driver RBH is using is one of the best if NOT the best 21" on the market. We get it, you don't like subs that cost $10k. Just imagine someone now responding to you that they can get 20 BIC subs for the price of your Dayton's that will be "Better"

 

[Verdinut]

There are many advantages to sealed vs ported for large high output, high excursion subs. The room gain for infrasonic bass in a sealed sub is superior compared to the ported sub below tuning. They will be offering a ported version but the enclosure is massive and I wouldn't put that in my theater room

When ported sub cabinets are tuned at 16 Hz as in the case of my three front subs, With the program material that I use, I never have to worry about over driving them below that frequency.

 

[shadyJ]

... 20 BIC subs for the price of your Dayton's that will be "Better"

To be fair, that would be a pretty fun and hilarious system.

 

[isolar8001]

20 BIC F12's would equal a BIC 240.....which would be the infamous "BIC BASSISINNAYOUFACE" configuration.

 

[lovinthehd]

LOL while I am not in the market, $10k apiece is some serious coin but still want to see what they do for a ported! Wonder how Deep Sea Sound's would compare.

 

[TLS Guy]

There are many advantages to sealed vs ported for large high output, high excursion subs. The room gain for infrasonic bass in a sealed sub is superior compared to the ported sub below tuning. They will be offering a ported version but the enclosure is massive and I wouldn't put that in my theater room

Yes, a ported sub with that driver, would likely be huge. Have RBH tested that sub to full power out of doors? I ask, as I think there is a serious risk that sub could produce a sonic boom. That could do a lot of damage. This phenomenon has occurred with people experimenting with devices like that. If they have not, they had better test it in open space. If it is possible someone will do it, and the law suits will come in.

I do find it hard to justify such a device in the home. I suppose it might be required for the odd effect, in a movie. However it has no practical application for any music I am aware of. I certainly never felt the need for increased bass output in my system and have at times in movies been concerned about structural damage. So I think this unit probably does get into the pointless realm. I could see that it might have an application in large cinemas, but not in any home I am aware of.