2 HSU over 1 Rythmik

S

shadyJ

Speaker of the House
Staff member
Just to update everything. I pulled the trigger on the Dual HSU subs.
Nice. If you live in an apartment, make contingency plans for your inevitable eviction. It'll be worth it though.

Properly blending in those subs with your speakers won't be altogether easy since you are using speaker level connections, but it is doable. Like I said before, you will want to plug the ports on your speakers. Make sure you get an airtight seal.

Make sure that the 'crossover' switch is flipped to 'in'.

After that, raise the 'crossover frequency' knob to where the subs bass meets the speaker's bass. You can kind of do this by ear but it helps to have a measuring device like a USB mic. If you do it by ear, use a test tone generator like this one.

Once the bass from the subs meet the speaker's output, flip the 'phase' switch back a forth between 0 degrees and 180 degrees, and listen for a lowering of loudness at the crossover frequency that you set using a test tone (btw, Hsu may send a disc with sample tracks and test tones in the packing sleeve of the shipping box). Leave the phase switch to whatever sounds the loudest at the crossover frequency. It will probably be 0 degrees, but it doesn't take much effort to check that. once you get the subs phase matched at the crossover frequency, you are set.

All you have to do then is determine how loud you want to run the subs. Again, if you don't have any measurements software, you can do this by ear by just setting the subwoofer's gain level to whatever sound most natural to your ear, however it can be more precisely done with measurement gear and software.
 
3db

3db

Audioholic Slumlord
Keep in mind that unless you use the line level inputs (which you won't be doing), the subs from Rythmik do not have a very extended high frequency response. This is some kind of odd consequence of their servo system. Not such a big deal if you intend to crossover at 80 Hz or lower, but the high end roll off starts like at 70 Hz:

That doesn't give you much flexibility for integration, and you will want all the flexibility you can get since you will have no bass management. The Hsu subs are flat out to 200 Hz with any connectivity. And two subs can give you a much better response and a much better sound than one sub. Two subs can also greatly reduce localization that happens with a single sub.

Something else to think about that will help integration is sealing the ports on your main speakers if they are ported models. That will provide a much more predictable low end and make phase matching between speakers and subs much easier. It's a bit like applying a more controlled high-pass filter to your speakers. What speakers are you using?
Wow Shady, you do have a nack for being stastician only revealing half truths to support your arguement. I call BS on your latest post and the previous Rythmik post which is also in error. Its no secret for your love affair of HSU but be fair and STOP telling half truths. Its getting rather disgusting. You seem to be on anti Rthymic kick just like you were a few years back with PSA and everyone remembers to what extreme you tried to discredit PSA.
 
S

shadyJ

Speaker of the House
Staff member
Wow Shady, you do have a nack for being stastician only revealing half truths to support your arguement. I call BS on your latest post and the previous Rythmik post which is also in error. Its no secret for your love affair of HSU but be fair and STOP telling half truths. Its getting rather disgusting.
Where am I in error?
 
ematthews

ematthews

Audioholic General
Nice. If you live in an apartment, make contingency plans for your inevitable eviction. It'll be worth it though.

Properly blending in those subs with your speakers won't be altogether easy since you are using speaker level connections, but it is doable. Like I said before, you will want to plug the ports on your speakers. Make sure you get an airtight seal.

Make sure that the 'crossover' switch is flipped to 'in'.

After that, raise the 'crossover frequency' knob to where the subs bass meets the speaker's bass. You can kind of do this by ear but it helps to have a measuring device like a USB mic. If you do it by ear, use a test tone generator like this one.

Once the bass from the subs meet the speaker's output, flip the 'phase' switch back a forth between 0 degrees and 180 degrees, and listen for a lowering of loudness at the crossover frequency that you set using a test tone (btw, Hsu may send a disc with sample tracks and test tones in the packing sleeve of the shipping box). Leave the phase switch to whatever sounds the loudest at the crossover frequency. It will probably be 0 degrees, but it doesn't take much effort to check that. once you get the subs phase matched at the crossover frequency, you are set.

All you have to do then is determine how loud you want to run the subs. Again, if you don't have any measurements software, you can do this by ear by just setting the subwoofer's gain level to whatever sound most natural to your ear, however it can be more precisely done with measurement gear and software.
Thanks for all the good info. The canton’s will be hard to plug as I would have to remove the baseplate to get to it. All my other speakers would be easy. And they come with plugs. The cantons don’t.
 
3db

3db

Audioholic Slumlord
Where am I in error?
Where did you get that graph for starters? Rythmik's F15HP starts to roll off at 70 but not the F18, or the F25 according to DBASE. Just because one rolls of doesnt mean all Rythmiks sub do. Rythmik amps do have selectable slopes but the way you worded that in the SVS comparison came across as Rythmik not having that option. Present all the facts or dont present any at all because selective or omission of facts comes across as nothing but personal bias.
 
S

shadyJ

Speaker of the House
Staff member
Thanks for all the good info. The canton’s will be hard to plug as I would have to remove the baseplate to get to it. All my other speakers would be easy. And they come with plugs. The cantons don’t.
You can still do all of that without plugging the port, but the problem is that the Cantons will probably have pretty deep extension, maybe down to 30 Hz. If you only had the subs play where the Canton's are rolling off, you would hardly get half an octave of use out of them. If you decide to use the subs to higher frequencies, then they will be outputting bass along with the Cantons, which is going to add up to a lot of bass if you run the Hsu subs at more the quiet levels.

However, I am looking at a product page for the speakers you have (these are them, right?), and it doesn't look like the baseplate would be blocking the port? Normally, tower speakers that have down-firing ports have this kind of arrangement:

But there is no spacing between the baseplate and cabinet that I can see in your Canton speakers. In fact, the bottom of the Canton speakers look like they would be so low to the ground that they would inhibit the functionality of any down-firing ports. Do you know if there is a picture of the bottom of that speaker that I could look at anywhere?
 
Pogre

Pogre

Audioholic Slumlord
Wow Shady, you do have a nack for being stastician only revealing half truths to support your arguement. I call BS on your latest post and the previous Rythmik post which is also in error. Its no secret for your love affair of HSU but be fair and STOP telling half truths. Its getting rather disgusting. You seem to be on anti Rthymic kick just like you were a few years back with PSA and everyone remembers to what extreme you tried to discredit PSA.
Disgusting? Perhaps your attitude. You seem to be disproportionately angry... are you personally invested in Rythmik or something..?

Shady helped me get set up with what I have right now and I greatly appreciated his help! I love what I have now and credit Shady a ton for helping me put it together! He puts real time and effort into helping others here as well. While you may disagree, which is fine, I think you could be a little less... douchey, and present your counter argument like a big boy. I've never seen Shady address anyone the way you just did.
 
S

shadyJ

Speaker of the House
Staff member
Where did you get that graph for starters? Rythmik's F15HP starts to roll off at 70 but not the F18, or the F25 according to DBASE. Just because one rolls of doesnt mean all Rythmiks sub do. Rythmik amps do have selectable slopes but the way you worded that in the SVS comparison came across as Rythmik not having that option. Present all the facts or dont present any at all because selective or omission of facts comes across as nothing but personal bias.
You are right that not all the Rythmik subs have low upper frequency roll-off points, but most of them do- so long as you are using inputs other then the LFE in. ematthews is using a speaker level input, not the LFE in. Look at the response graphs for the models you mentioned when not using the LFE input:
F18:

LV12R:

F25HP:


The F25HP isn't that bad at the high end, but we still see the upper end roll-off at 70 Hz. It probably wouldn't be very audible though, however the F18 could be a problem. The fundamental performance of the Rythmik subs are good, but they are not subs I would recommend if you are not going to use the LFE input and may be crossing them over higher than 80 Hz.

However you are right that Rythmik has selectable low-end slopes, I must have forgotten about that. However the degree of flexibility is not nearly as much as what SVS offers.
 
S

shadyJ

Speaker of the House
Staff member
I was wrong. The base plate is part of the port.
It shouldn't be very difficult to plug then? If you have polyurethane foam lying around, an easy port plug to make would be to just cut out a circular part that is the diameter of the port, so long as it is a couple inches thick. You could even used a rolled-up towel, so long as you have a snug fit and it occupies enough of the port length.
 
3db

3db

Audioholic Slumlord
You are right that not all the Rythmik subs have low upper frequency roll-off points, but most of them do- so long as you are using inputs other then the LFE in. ematthews is using a speaker level input, not the LFE in. Look at the response graphs for the models you mentioned when not using the LFE input:
F18:

LV12R:

F25HP:


The F25HP isn't that bad at the high end, but we still see the upper end roll-off at 70 Hz. It probably wouldn't be very audible though, however the F18 could be a problem. The fundamental performance of the Rythmik subs are good, but they are not subs I would recommend if you are not going to use the LFE input and may be crossing them over higher than 80 Hz.

However you are right that Rythmik has selectable low-end slopes, I must have forgotten about that. However the degree of flexibility is not nearly as much as what SVS offers.
Ryhmik subs are not subs? What are they then other than just another PSA target? When Rythmik released their HP15 back in the day, nothing from SVS nor HSU could outperform it. So does that mean HSU and SVS didnt make subs back then?

It took me calling you out again .....One input is band limited, the other goes to 200 Hz but you failed to mention this. Ematthews made the right choice not because of what Rythmik can or cant do but because he can get 2 HSU subs for the price of a single Rythmik whose performance is to close to tge HSU to call one better than the other.
 
Last edited:
KEW

KEW

Audioholic Overlord
Just to update everything. I pulled the trigger on the Dual HSU subs.
Congratulations!
You brought the Outlaw sub upstairs to establish that a sub was a good upgrade for your music system and ended up getting dual ULS-15's!
Enjoy the honeymoon while it lasts!
However, it is obvious that you have not followed this to its logical conclusion!
Then, you need to set up the dual Hsu subs downstairs to establish the benefit of dual subs in your HT room.
After you have bought the second Outlaw, then and only then will you be done and able to rest!
Such is the way of subwoofers!
 
S

shadyJ

Speaker of the House
Staff member
Ryhmik subs are not subs? What are they then other than just another PSA target? When Rythmik released their HP15 back in the day, nothing from SVS nor HSU could outperform it. So does that mean HSU and SVS didnt make subs back then?
It's a bit of an overstatement to say that the PB13 would not outperform the FV15Hp back in the day. Those subs are going for different performance targets. SVS generally aims for pristine performance down to port tuning. Their subs are typically very low distortion. Compare the CEA-2010 distortion quantities of the FV15HP vs the PB13. Rythmik allows more distortion. SVS also tend to exceed competing sub's output at around port tuning. Historically they have done this at the expense of mid-bass output, but with the introduction of the 3000 series, that looks like its changing. You might argue that Rythmik's allowed distortion, which isn't bad, is good enough and that SVS goes for overkill in that respect, but that is a different discussion.

As for Hsu, their VTF15h subs was much less expensive, so it doesn't make as much sense to compare to Rythmik's then flagship sub. If Hsu did want to make a monster sub to compete with the other flagships from SVS, Monolith, PSA, JTR, Rythmik, etc., I am sure they could. But I think they would rather users just buy multiples of their existing subs and consider that a monster sub system.
 
ematthews

ematthews

Audioholic General
You can still do all of that without plugging the port, but the problem is that the Cantons will probably have pretty deep extension, maybe down to 30 Hz. If you only had the subs play where the Canton's are rolling off, you would hardly get half an octave of use out of them. If you decide to use the subs to higher frequencies, then they will be outputting bass along with the Cantons, which is going to add up to a lot of bass if you run the Hsu subs at more the quiet levels.

However, I am looking at a product page for the speakers you have (these are them, right?), and it doesn't look like the baseplate would be blocking the port? Normally, tower speakers that have down-firing ports have this kind of arrangement:

But there is no spacing between the baseplate and cabinet that I can see in your Canton speakers. In fact, the bottom of the Canton speakers look like they would be so low to the ground that they would inhibit the functionality of any down-firing ports. Do you know if there is a picture of the bottom of that speaker that I could look at anywhere?
Hey. Am I correct in reading this that the subs would be easier to blend with Bookshelf speakers. I have a few of them that would do the trick. Kef LS50. JBL Studio 530. Polk LSi.
I do love my Cantons however.
 
S

shadyJ

Speaker of the House
Staff member
Hey. Am I correct in reading this that the subs would be easier to blend with Bookshelf speakers. I have a few of them that would do the trick. Kef LS50. JBL Studio 530. Polk LSi.
I do love my Cantons however.
They are not easier to blend in with bookshelf speakers exactly, its just that, with the way you are hooking them up via speaker level connection. they get to do more with bookshelf speakers since bookshelf speakers don''t have as much low-frequency extension, especially if you plug the bookshelf speaker ports. If you plug the ports on many bookshelf speakers you are looking at maybe a 90 or 100 Hz extension till the response knee. On the typical tower speaker, that might be 60 Hz. It can vary wildly though, depending on design.
 
Pogre

Pogre

Audioholic Slumlord
They are not easier to blend in with bookshelf speakers exactly, its just that, with the way you are hooking them up via speaker level connection. they get to do more with bookshelf speakers since bookshelf speakers don''t have as much low-frequency extension, especially if you plug the bookshelf speaker ports. If you plug the ports on many bookshelf speakers you are looking at maybe a 90 or 100 Hz extension till the response knee. On the typical tower speaker, that might be 60 Hz. It can vary wildly though, depending on design.
So plugging a ported speaker pretty much just changes the bass response and doesn't affect midrange or cause any otherwise unwanted behavior? I've always wondered about that.
 
S

shadyJ

Speaker of the House
Staff member
So plugging a ported speaker pretty much just changes the bass response and doesn't affect midrange or cause any otherwise unwanted behavior? I've always wondered about that.
Plugging a port can alter the response above low frequencies, but it wouldn't normally do so by much. It might take out some odd high-Q resonance that would scarcely have been audible in the first place. In many loudspeakers, plugging the port would probably do more good than harm for midrange frequencies, but more so in an acoustic measurement than anything you would actually hear.
 
3db

3db

Audioholic Slumlord
It's a bit of an overstatement to say that the PB13 would not outperform the FV15Hp back in the day. Those subs are going for different performance targets. SVS generally aims for pristine performance down to port tuning. Their subs are typically very low distortion. Compare the CEA-2010 distortion quantities of the FV15HP vs the PB13. Rythmik allows more distortion. SVS also tend to exceed competing sub's output at around port tuning. Historically they have done this at the expense of mid-bass output, but with the introduction of the 3000 series, that looks like its changing. You might argue that Rythmik's allowed distortion, which isn't bad, is good enough and that SVS goes for overkill in that respect, but that is a different discussion.
What are the two different markets here Shady? Im really curious to know. As far as distortion goes, as long as its inaudible, who cares. The analogy of chasing the lowest distortion levels to well past the point of inaudible is a waste of time and resources. You might argue that SVS is wasting their resources on a zero point gain.


As for Hsu, their VTF15h subs was much less expensive, so it doesn't make as much sense to compare to Rythmik's then flagship sub. If Hsu did want to make a monster sub to compete with the other flagships from SVS, Monolith, PSA, JTR, Rythmik, etc., I am sure they could. But I think they would rather users just buy multiples of their existing subs and consider that a monster sub system.
[/QUOTE]
As you know, Rythmik makes many models, so one can say that Rythmik is also in the game off offering multiple cheaper subs and are more than a monster sub company.
 
S

shadyJ

Speaker of the House
Staff member
What are the two different markets here Shady? Im really curious to know. As far as distortion goes, as long as its inaudible, who cares. The analogy of chasing the lowest distortion levels to well past the point of inaudible is a waste of time and resources. You might argue that SVS is wasting their resources on a zero point gain.
I would say the SVS sub was a bit more 'high-end' mostly due to its crazy build-quality. The thing is like a boulder. If you haven't come into contact with one, you should. The Rythmik subs also have good build quality, but they just don't match the higher end of what SVS does. This has both an advantage and disadvantage because those SVS subs are painful to have to move around. I agree that distortion doesn't matter so long as it is inaudible, but it is a performance metric, and in this respect the PB13-Ultra was and still is a superb performer that is not matched by the FV15HP. You said that nothing could outperform the FV15HP, but that is a blanket statement since there is more to performance than raw SPL.
 
Pogre

Pogre

Audioholic Slumlord
Plugging a port can alter the response above low frequencies, but it wouldn't normally do so by much. It might take out some odd high-Q resonance that would scarcely have been audible in the first place. In many loudspeakers, plugging the port would probably do more good than harm for midrange frequencies, but more so in an acoustic measurement than anything you would actually hear.
This tempts me to plug my towers and run another calibration just to experiment. I don't expect any big improvements or anything. Just a time killer to satisfy my curiosity. I've been staying busy through all this but we may end up on lock down sooner than later and the distraction would be welcome.
 

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