Post Review - HSU vs Rhythmik

[its phillip]

An A7-900 nearfield would probably collapse a lung or something

 

[MarkMM]

Thanks for all the input (this and my other posts.) Just pulled the trigger on the HSU. Would rather save the $400 difference, towards a second VTF if need be in the future.

Suppose I just jinxed the HSU shootout review.

 

[clouso]

Thanks for all the input (this and my other posts.) Just pulled the trigger on the HSU. Would rather save the $400 difference, towards a second VTF if need be in the future.

Suppose I just jinxed the HSU shootout review.

you bastard you ordered it before me...hahaha...congrats and pls let us know about it when you hook it up..........

 

[sholling]

An A7-900 nearfield would probably collapse a lung or something

What a way to go.

Besides my PB12-Plus/2 sits 2' behind the sofa.

 

[clouso]

What a way to go.

Besides my PB12-Plus/2 sits 2' behind the sofa.

I wont tell you the size of my room right now....you would tell me im insane to get a VTF-15H............but we must think long term.. dont we?..........

 

[GranteedEV]

I wont tell you the size of my room right now....you would tell me im insane to get a VTF-15H............but we must think long term.. dont we?..........

From what it sounds like

Get two

Just remember, since it is a ported sub, you might get the best results in a small room if you put it in its sealed or lowest extention modes.

 

[Sputter]

Yeah...i am trying to audition the most i can but in my area i cannot...but i read a lot and learn a lot..and btw GraneedEV...i already bouth and sold stuff online and you are right...lower prices....but HSU will be my first online buy from a true manufaturer...i have been looking for them here in Canada and didnt find any dealers..... yes i will be making a blind purchase...but like i said before here i am trusting you guys and im sure the VTF-15H will be another upgrade in my setup.................

As you found out, there are no dealers in Canada for HSU.

 

[Sputter]

I wont tell you the size of my room right now....you would tell me im insane to get a VTF-15H............but we must think long term.. dont we?..........

umm, are talking bathroom size?

 

[clouso]

From what it sounds like

Get two

Just remember, since it is a ported sub, you might get the best results in a small room if you put it in its sealed or lowest extention modes.

yes exactly..thats what im loving about this sub already without owning it yet...5 tuning modes..............

 

[cschang]

yes exactly..thats what im loving about this sub already without owning it yet...5 tuning modes..............

The Rythmik essentially has 9. Three different extension modes X Three different damping modes.

 

[clouso]

The Rythmik essentially has 9. Three different extension modes X Three different damping modes.

ok the rythmik as 9 tuning modes so its a better sub...thx....

 

[ntrain42]

ok the rythmik as 9 tuning modes so its a better sub...thx....

Actually its more than 9 tuning modes, forgot you have to figure in the port plug modes as well.

But thats not why Rythmik is a better sub. It just uses a much higher quality driver, plate amp and overall is a more refined design IMO. My favorite HSU is the sealed ULS-15, and its a very good sub for the price. But its not quite as clean sounding or detailed in the upper bass frequencies as the F15HP.

 

[billy p]

Wouldn't it be wise just to run the sub in the tune is was designed for and most ported designed are between 18-21?

 

[templemaners]

It just uses a much higher quality driver, plate amp and overall is a more refined design IMO.

Can you please go into more detail with how you came to that opinion? I get that the Rythmik could be called a better design because of the servo technology, but I'm not understanding how the Rythmik has a much higher quality driver & plate amp.

 

[cschang]

ok the rythmik as 9 tuning modes so its a better sub...thx....

ntrain beat me to it, but I will reiterate.....that isn't the point.

 

[ntrain42]

Can you please go into more detail with how you came to that opinion? I get that the Rythmik could be called a better design because of the servo technology, but I'm not understanding how the Rythmik has a much higher quality driver & plate amp.

You ever look at Rythmiks DS1510 driver? Compare it to ANYTHING HSU has out.

A. 3" aluminum former/voice coil w/200oz magnet/shorting ring
B. That same voicecoil is matched to a solid spun one piece anodized aluminum cone that further acts as a natural heatsink to remove heat from the voicecoil FAST reducing natural thermal compression artifacts.(The Fs of this driver is a scant 15hz btw)
C. 40mm peak to peak LINEAR excursion, butyl rubber surround, reinforced dual weave spider with interwoven leads and gold plated high spring tension binding posts.
D. 12 Spoke ridgid cast aluminum frame with VC venting.

This is not exactly a cheap "off the shelf" driver that you would find in a competing product like HSU,Epik or eD.

The plate amp is of similiar quality. Rythmik uses Class A/B or Class H custom plate amps featuring large toroidal power supplies, large secondary capacitance for the rails and use quality OP amps in the singal path. These plate amps have very high S/N ratio and are true analog amps. Not the typical generic run of the mill Class D chip amps you see dropped into alot of subs these days.

The nice thing with Rythmik, the owner(Brian Ding), the website etc. is you can actually get things like the T/S parameters, see plenty of up close quality pics of the drivers and amps used(the innards that is), get real information on the parts used on those said amps etc. the information is put out there and the companies products and designs are open to scrutinizing, improvments and ideas. You can talk theory and physics on audio properties if you want with Brian on how to improve SQ and enjoyment for your own system and products used. It doesn't get any better than this.

Ever try and get information on an eD,Epik or HSU? Like information on their drivers T/S parameters, box enclosure size, port size and length, tuning etc? Its not readily available there and getting that information is like pulling teeth for those who want to really find out what their hard earned dollar spent gets them. Small things like this though along with a killer subwoofer product is why I really love Rythmik and doing business with them. Hell you can even buy the drivers and plate amps seperately for DIY installs. Can't beat that.

 

[templemaners]

Thank you for taking time to respond, ntrain42.

First, let me preface this by saying this is not to be meant as a slam on Rythmik. From what I've seen and read, they look like they make a very high quality product and are good to work with. But I have a couple problems with what you said:

You ever look at Rythmiks DS1510 driver? Compare it to ANYTHING HSU has out.

A. 3" aluminum former/voice coil w/200oz magnet/shorting ring
B. That same voicecoil is matched to a solid spun one piece anodized aluminum cone that further acts as a natural heatsink to remove heat from the voicecoil FAST reducing natural thermal compression artifacts.(The Fs of this driver is a scant 15hz btw)
C. 40mm peak to peak LINEAR excursion, butyl rubber surround, reinforced dual weave spider with interwoven leads and gold plated high spring tension binding posts.
D. 12 Spoke ridgid cast aluminum frame with VC venting.

This is not exactly a cheap "off the shelf" driver that you would find in a competing product like HSU,Epik or eD.

I can understand using an off the shelf driver on a lower level product within their lineups, but Epik and HSU's description of their higher level products seem to contradict that statement:

HSU VTF-15H:

15” front-firing custom-made driver, designed from the ground up for exceptionally flat frequency response and low distortion, best-in-class response linearity

http://forum.hsuresearch.com/showpost.php?p=76547&postcount=1

Epik Empire:

The Empire uses a pair of proprietary 15 inch drivers. They each utilize a Kevlar-reinforced paper pulp cone for maximum stiffness and rigidity while retaining a lightweight cone that reacts quickly to changes in music or movies. The driver’s surround and spider are optimized for our sealed cabinet and provide linear operation throughout their range.

http://www.epiksubwoofers.com/empire.html

It could be marketing word play, but I take those descriptions to mean anything but cheap and off the shelf.

The plate amp is of similiar quality. Rythmik uses Class A/B or Class H custom plate amps featuring large toroidal power supplies, large secondary capacitance for the rails and use quality OP amps in the singal path. These plate amps have very high S/N ratio and are true analog amps. Not the typical generic run of the mill Class D chip amps you see dropped into alot of subs these days.

I will have to do more research for my own benefit, but I didn't think that a Class D amp was a detriment to performance? It leads me to wonder what type of amplifier design works best for subwoofers.... Class D's seem to be pretty prevalent in the industry (SVS, eD, Seaton, Epik and HSU all seem to use them, though HSU does mention that the VTF-15 has a class A/B output stage). I think it would be reasonable that if Class D amps were underwhelming, these companies wouldn't be using them in their higher price range products (defined to me as being ~$2000).

Also, how did you come to the conclusion that these plate amps have a very high S/N ratio? Are there measurements available that you could share with us? I couldn't find anything on the Rythmik website making that claim, although I have not searched the net at large for that information either.

The nice thing with Rythmik, the owner (Brian Ding), the website etc. is you can actually get things like the T/S parameters, see plenty of up close quality pics of the drivers and amps used(the innards that is), get real information on the parts used on those said amps etc. the information is put out there and the companies products and designs are open to scrutinizing, improvments and ideas. You can talk theory and physics on audio properties if you want with Brian on how to improve SQ and enjoyment for your own system and products used. It doesn't get any better than this.

I am glad to hear that Rythmik has a responsive owner that is willing to work with his customers to get the best sound possible from his products. It's certainly not something you would be able to get from a B&M brand...

Ever try and get information on an eD,Epik or HSU? Like information on their drivers T/S parameters, box enclosure size, port size and length, tuning etc? Its not readily available there and getting that information is like pulling teeth for those who want to really find out what their hard earned dollar spent gets them. Small things like this though along with a killer subwoofer product is why I really love Rythmik and doing business with them. Hell you can even buy the drivers and plate amps seperately for DIY installs. Can't beat that.

I don't understand why it is so surprising that these other manufacturers would not be willing to share that information - I'd consider that proprietary info and I would argue those companies have much more to lose by sharing that information to the public than they would in using it to convince the small fraction of the population that basically wants to double check the subwoofer manufacturers work. More disclosure is never a bad thing, but I'd have no complaints if that information was not available with a pre-made product. I guess it's a leap of faith on my part to believe that the people designing my sub are competent.

Rythmik has more of a reason to disclose things like driver T/S parameters, since they sell those products separately. I highly doubt that many DIY'ers would buy a driver without first knowing some specs. Also, in fairness to eD, they list some T/S parameters on their website as well (for the sake of argument, I'll assume those measurements are accurate):

http://www.edesignaudio.com/index.php?cPath=1_21

For example, that fridge sized A7-900 sub by eD states that it is using their Ov.2 subwoofer. It doesn't seem too logicial to me that they would us a woofer that had slightly different specs than the version used in their finished product. Although, I thought I remembered reading at some point that the individual JL Audio W7 subwoofers had slightly different specs than the versions used in their Fathom series...

Anyways, I think that's all I have. Thanks again for the response.

 

[ntrain42]

Thank you for taking time to respond, ntrain42.

First, let me preface this by saying this is not to be meant as a slam on Rythmik. From what I've seen and read, they look like they make a very high quality product and are good to work with. But I have a couple problems with what you said:



I can understand using an off the shelf driver on a lower level product within their lineups, but Epik and HSU's description of their higher level products seem to contradict that statement:

HSU VTF-15H:

http://forum.hsuresearch.com/showpost.php?p=76547&postcount=1

Epik Empire:

http://www.epiksubwoofers.com/empire.html

It could be marketing word play, but I take those descriptions to mean anything but cheap and off the shelf.



I will have to do more research for my own benefit, but I didn't think that a Class D amp was a detriment to performance? It leads me to wonder what type of amplifier design works best for subwoofers.... Class D's seem to be pretty prevalent in the industry (SVS, eD, Seaton, Epik and HSU all seem to use them, though HSU does mention that the VTF-15 has a class A/B output stage). I think it would be reasonable that if Class D amps were underwhelming, these companies wouldn't be using them in their higher price range products (defined to me as being ~$2000).

Also, how did you come to the conclusion that these plate amps have a very high S/N ratio? Are there measurements available that you could share with us? I couldn't find anything on the Rythmik website making that claim, although I have not searched the net at large for that information either.



I am glad to hear that Rythmik has a responsive owner that is willing to work with his customers to get the best sound possible from his products. It's certainly not something you would be able to get from a B&M brand...



I don't understand why it is so surprising that these other manufacturers would not be willing to share that information - I'd consider that proprietary info and I would argue those companies have much more to lose by sharing that information to the public than they would in using it to convince the small fraction of the population that basically wants to double check the subwoofer manufacturers work. More disclosure is never a bad thing, but I'd have no complaints if that information was not available with a pre-made product. I guess it's a leap of faith on my part to believe that the people designing my sub are competent.

Rythmik has more of a reason to disclose things like driver T/S parameters, since they sell those products separately. I highly doubt that many DIY'ers would buy a driver without first knowing some specs. Also, in fairness to eD, they list some T/S parameters on their website as well (for the sake of argument, I'll assume those measurements are accurate):

http://www.edesignaudio.com/index.php?cPath=1_21

For example, that fridge sized A7-900 sub by eD states that it is using their Ov.2 subwoofer. It doesn't seem too logicial to me that they would us a woofer that had slightly different specs than the version used in their finished product. Although, I thought I remembered reading at some point that the individual JL Audio W7 subwoofers had slightly different specs than the versions used in their Fathom series...

Anyways, I think that's all I have. Thanks again for the response.

Ill try and answer this in order from the quotes above.

A. Does Epik even have any "higher" level products?

Can you tell me what the T/S parameters are? WHat size and material the VC is made of? SHorting ring if any? Cast aluminum basket? No, I can tell you Epik's Empire sub uses a pair of pretty cheap drivers that feature a generic stamp steel basket, foam surround, Im not sure what the voice coil size is or what its is made of but Im sure its a kypton former and not aluminum. Here is a link: http://epiksubwoofers.com/empire.html Scroll down to the "drivers" section. Not exactly a high end unit and no T/S parameters are given either. I mean for $799 what do you expect? 2 drivers opposed in a small enclosure to minimize shipping costs and a class D chip amp.
And this is just one example. Same can be said for HSU..........show me some T/S parameters from HSU's website.

HSU is basically all marketing..........and please explain to me what HSU's "best in class" marketing bull is supposed to mean? LOL! Its a joke.

WHat do you REALLY KNOW about the HSU front firing driver? WHat is custom about it? T/S parameters? Pictures? Breakdown of its design and materials used? Funny how none of that stuff is kicking around isn't it? Use your common sense here is all I can say.

And a pulp cone reinforced by kevlar or nylon or a composite of some type is pretty generic these days and very common. Don't let em fool you? Nothing exotic about the driver HSU or Epik uses as an example.

On the amp section. CLass D chip amps are extremely efficient and they are absolutely DIRT CHEAP to mass produce. Mfg's use them because they are dirt cheap to produce, efficient in power usage(so 1000 plus watt amps are common) and work well in subwoofers because the lower frequencies can easily mask the natural SQ deficiencies of most class D amps.

Analog class A/B and G/H amps on the other hand are significantly more expensive to produce. You just don't see many subs with them these days. ANd with the trend towards subwoofers needing a kilowatt of power or more its more practical and much less expensive to make a small compact class D chip amp than a good analog amplifier of the same power. Rythmik's 600 watt Class H(basically a much more efficient class A/B amp with variable voltage rails)plate amp weighs about 25-30 pounds on its own. Its extremely heavy for a sub plate amp.

And yes eD does disclose alot of info on their drivers. Their drivers are decent. I owned a few different ED HT subs, but I just wasn't really impressed with their performance(surprisingly the sealed ones). THe plate amps they use just plain suck and are not relaible at all IMO. Of the 2 pairs I owned over the course of 3 months I had one DOA and 2 failures. And I am the type who keeps the gains very low and does not over drive a product to get output. If I need more output, I buy and daisy chain another sub into the mix.

 

[cschang]

Hsu doesn't use an "off the shelf" driver for any of their subs. They may not be built like the Rythmik, but certainly not off the shelf.

Different philosophies for sure, I have owned both(currently Rythmik), have communicated with both, have actually been to Hsu's shop on a number of occasions, and I have regard for both Brian(Dr. Ding) and Dr. Hsu.

 

[ntrain42]

Hsu doesn't use an "off the shelf" driver for any of their subs. They may not be built like the Rythmik, but certainly not off the shelf.

Different philosophies for sure, I have owned both(currently Rythmik), have communicated with both, have actually been to Hsu's shop on a number of occasions, and I have regard for both Brian(Dr. Ding) and Dr. Hsu.

I politely beg to differ. The ULS-15 driver is made and distributed by who as for one example? I think the word "custom" is a term that is really used loosely in the AV industry.