Revel reintroduces their $10,000 sealed 18" sub

[Irvrobinson]

With it being new just wondered if it's a typo of sorts.

Now that I read the brochure again, you might be right. The brochure says it has a 4"x1.75" voice coil, which would imply a peak-to-peak measurement, not really an xmax. That would also put the xmax in the 20-22mm range, which would be more normal. Also, maybe I'm just being a dolt, but that surround doesn't look heroic enough for a 40mm+ xmax. Look at the surrounds on the 5400, the Velodyne DD18 Plus, and the JL Audio products. The Revel's surround looks wimpy by comparison. Perhaps this is a case of a marketing guy that didn't really know what he was talking about.

 

[monkish54]

Features:
» Standard-setting output capability and low distortion
» Massive 18-inch woofer with dual 4-inch x 1.75-inch
voice coils and neodymium motor structures
» Ultralow-distortion motor system with symmetrical
magnetic fields and mirror-image spider design to
cancel distortion; no servo feedback system required
» Two ultrahigh-power amplifiers with a total of 2,000W
RMS and 4,000W peak output for low dynamic
compression at very high output levels
» Sophisticated self-protection circuitry allows
unprecedented dynamics for extraordinarily lifelike bass

» 18-inch cast-frame woofer
» 4-inch-diameter voice coil
» 1.7-inch Xmax
» 2,000WRMS / 4,000W peak power
» Over 115dB acoustic output
» High-resolution DSP room EQ
» Fully configurable electronic crossover
» High-pass room EQ
» PC setup via USB
» Dimensions (H x W x D): 24.6" x 27.9" x 28.1"
(625mm x 709mm x 714mm)
» Product weight: 177 lbs (80kg)

Looks a bit wonky to me...

 

[templemaners]

Looks a bit wonky to me...

1.7 in does equal 43.18 mm (according to google). Good thing it's 1.7 in and not 1.7 mm

 

[monkish54]

LOL

The problem wasn't that 1.75" doesn't equal 44.45mm, our very own Irv converted that for us.

The problem is the math doesn't add up. The formula is:

Xmax= (voice coil length - magnetic gap height)/2

We have 2 of the 3 variables. If the VC length is 1.75", the magnetic gap would have to be -1.75" high to result in an xmax of 1.75".

 

[jinjuku]

I'm putting $$ on ~22mm X-Max one way.

 

[monkish54]

I'll take that bet!

Unfortunately, there's a problem with that too.

If the Xmax is 22.225mm and the VC length is 44.45mm (they said in several different places the VC is 4" X 1.75") the gap would have to be 0mm.

 

[Irvrobinson]

I'll take that bet!

Unfortunately, there's a problem with that too.

If the Xmax is 22.225mm and the VC length is 44.45mm (they said in several different places the VC is 4" X 1.75") the gap would have to be 0mm.

Yeah, xmax is probably 20mm, at best. Maybe this Revel is a 25-30Hz wonder.

 

[jinjuku]

I'll take that bet!

Unfortunately, there's a problem with that too.

If the Xmax is 22.225mm and the VC length is 44.45mm (they said in several different places the VC is 4" X 1.75") the gap would have to be 0mm.

I wasn't looking too hard at the spec. Just that 44mm isn't accurate

 

[GranteedEV]

The problem is the math doesn't add up. The formula is:

Xmax= (voice coil length - magnetic gap height)/2

Not really. that's just a random formula some companies use to give a very generic, and probably useless, xmax number.

A lot of companies are starting to use the 30% down BL for xmax, while others yet more conservatively factor in variations in suspension compliance and inductance. Others just use xmax as a number where mechanical noise is apparent during testing. An Re XXX has a 3" voice coil, yet sports a massive 54mm one way xmax.... That "formula" alone would necessitate a 4.25" "voice coil length - gap length".

 

[monkish54]

very generic, and probably useless, xmax number.

I don't disagree.

A lot of companies are starting to use the 30% down BL for xmax

I said that earlier.

Still, a 4" x 1.75" VC with an xmax of 1.75"...I imagine that would be one small gap even if they were using 70% BL value.

An Re XXX has a 3" voice coil, yet sports a massive 54mm one way xmax.... That "formula" alone would necessitate a 4.25" "voice coil length - gap length".

Isn't 3" the VC diameter not length?

BTW, you have a PM.

 

[gene]

We are working on a preview article on this sub and sending Revel a list of questions to answer.

so far they have given us the following info:

• The rated output is 115dB or greater above 30Hz, and you can set it for “Normal,” at which it is -3dB at 20 Hz, or “Extended,” at which it is -3dB at 16 Hz.
• The baffle is 1.5” thick.
• There is extremely flexible software for high-resolution equalization, with 10 PEQs available for the low-pass.
• It also features true adjustable delay (in contrast to the almost useless phase controls that are ubiquitous), which contributes to its superior ability to be properly integrated with the high-pass loudspeakers.
• It is set up for use with one to four speakers in a chain, making basic equalization easier.
• Significantly, the critical contribution of the high-pass speakers is taken into account in the low-pass equalization. Without such a feature subwoofer EQ is mostly useless.
• The most sophisticated implementation is to use Harman's ARCOS room characterization system with their proprietary algorithms to achieve “Sound Field Management,” drastically reducing seat-to-seat variation at low frequencies.

If you have a list of questions you want answered, try to put them in one concise post and I will submit them. thanks.
<!--[if gte mso 9]><![endif]--><!--[if gte mso 10]> <![endif]-->

 

[monkish54]

If you have a list of questions you want answered, try to put them in one concise post and I will submit them. thanks.
<!--[if gte mso 9]><![endif]--><!--[if gte mso 10]> <![endif]-->

Wow, thanks Gene!

I have a few questions, none of which they will answer:

1. How does Revel determine xmax?
2. What is the Xmax of this subwoofer?
3. How long is the magnetic gap?
4. How many VC layers?
5. Is it possible to see a BL vs Displacement graph?
6. How about VC LE vs displacement/heat?

Thanks, Gene.


Important
To make it easier on you, I propose everyone who submits questions puts the Phrase "Revel Subwoofer Questions" somewhere in the post, that way you can search the thread for those key words and all the questions will appear.

 

[jinjuku]

I have no questions since I'm not a target audience for that sub. Carry on

 

[gene]

I have some new data on the driver mechanics:

• <!--[if gte mso 9]><![endif]--> Mechanical Xmax is 1.7 inches (not peak-to-peak).
• Linear Xmax is approximately 1 inch (not peak-to-peak).
• The brochure should have said 4” diameter dual 1.75”-long voice coils. There are of course also dual magnetic gaps.

Revel also sent us CEA data but I want to clarify how it was measured before we include in the preview article.

 

[Nuance AH]

I have some new data on the driver mechanics:

• <!--[if gte mso 9]><![endif]--> Mechanical Xmax is 1.7 inches (not peak-to-peak).
• Linear Xmax is approximately 1 inch (not peak-to-peak).
• The brochure should have said 4” diameter dual 1.75”-long voice coils. There are of course also dual magnetic gaps.

Revel also sent us CEA data but I want to clarify how it was measured before we include in the preview article.

I have to admit, Revel (one of the "Big Dogs") is being quite open concerning the specifications of this new subwoofer; I applaud them for that. My question to them is the most important of all: When will they be sending me one for beta testing?

 

[Irvrobinson]

We are working on a preview article on this sub and sending Revel a list of questions to answer.

so far they have given us the following info:

• The rated output is 115dB or greater above 30Hz, and you can set it for “Normal,” at which it is -3dB at 20 Hz, or “Extended,” at which it is -3dB at 16 Hz.
• The baffle is 1.5” thick.
• There is extremely flexible software for high-resolution equalization, with 10 PEQs available for the low-pass.
• It also features true adjustable delay (in contrast to the almost useless phase controls that are ubiquitous), which contributes to its superior ability to be properly integrated with the high-pass loudspeakers.
• It is set up for use with one to four speakers in a chain, making basic equalization easier.
• Significantly, the critical contribution of the high-pass speakers is taken into account in the low-pass equalization. Without such a feature subwoofer EQ is mostly useless.
• The most sophisticated implementation is to use Harman's ARCOS room characterization system with their proprietary algorithms to achieve “Sound Field Management,” drastically reducing seat-to-seat variation at low frequencies.

If you have a list of questions you want answered, try to put them in one concise post and I will submit them. thanks.
<!--[if gte mso 9]><![endif]--><!--[if gte mso 10]> <![endif]-->

Some of these specs are very similar to the Velodyne DD18 Plus. It should be interesting to see if Harman's measurement software is better than Velodyne's, which IMO is useless. This looks like a potentially interesting product, but the price still seems high, which is somewhat of a surprise considering that the Salon 2 is actually something of a price-performance bargain, especially at actual street prices. The cabinet appears nicer than Velodyne's, but pictures can be deceiving. Certainly that 177lb net weight implies something special somewhere.

It strikes me as odd that Revel would go for great price performance in a full-range speaker, which is really difficult to do, and get pricey on a subwoofer, where the competition is very deep.

 

[Irvrobinson]

I have some new data on the driver mechanics:

• <!--[if gte mso 9]><![endif]--> Mechanical Xmax is 1.7 inches (not peak-to-peak).
• Linear Xmax is approximately 1 inch (not peak-to-peak).
• The brochure should have said 4” diameter dual 1.75”-long voice coils. There are of course also dual magnetic gaps.

Revel also sent us CEA data but I want to clarify how it was measured before we include in the preview article.

25mm is much more inline with what one would expect, though that surround still looks wimpy even for 25mm. Letting those original xmax and voice coil specs get into a brochure is indicative of a really poor product release process.

 

[AcuDefTechGuy]

Gene, did you ask Revel if they wanted to send you this Sub for review....along with a pair of Salon2 & ML monoblocks?

 

[gene]

Some of these specs are very similar to the Velodyne DD18 Plus. It should be interesting to see if Harman's measurement software is better than Velodyne's, which IMO is useless. This looks like a potentially interesting product, but the price still seems high, which is somewhat of a surprise considering that the Salon 2 is actually something of a price-performance bargain, especially at actual street prices. The cabinet appears nicer than Velodyne's, but pictures can be deceiving. Certainly that 177lb net weight implies something special somewhere.

It strikes me as odd that Revel would go for great price performance in a full-range speaker, which is really difficult to do, and get pricey on a subwoofer, where the competition is very deep.

Agreed with you about the Velodyne measurement software being pretty much a useless endeavor if you even remotely care about accuracy. But the manual EQ is the most flexible I've used and essential in my setup. But I still must use external measurement devices since Velodyne's resolution is limited to 1/3rd Octave.

When I compare the Revel CEA #s to what we measured on the Velodyne DD-18+, the Revel appears to really limit output below 30Hz to pass CEA distortion tests, but it rips above 40Hz with a decisive advantage over the Velodyne. The Velo motor structure is likely more robust than the Revel, but the bigger amp of the Revel is what gives it an output advantage at higher F.

 

[Sheep]

They call it xmax, and Harman is usually pretty good about definitions, but I wondered if there were differences in how xmax could be measured. Like perhaps where the driver is near linear and where it isn't. Not that I'm any sort of expert here, but I don't ever think I've seen a driver spec'd with an xmax that large. Watch, monkish will now produce a list of eight of them.

There is xmax and xsus. Xmas is linear travel. Xsus is the full travel the suspension can do, regardless of linearity.

SheepStar