This is probably a question for Peter or Dr. Hsu,

To my knowledge no detailed measurments are available on the internet for the HSU HO w/ turbo and HSU 3.3 w/turbo. When I say detailed, I mean something along the lines of what Ilkka has done. Craig's measurments are useful too but I need more details. Ilkka's measurements of the 3.2 especially the Max SPL at the threshold of compression and the max spl achievable with compression are in the attachment here. Please take a good look at it and if you can shed some light into what can be expected from the Ho w/turbo and the 3.3 w/turbo, that would be great. In room measurments will not be a good idea to factor in here.

If the attached chart's values are keyed into excel and then based on knowledge if the expected performance of the two other subs can be posted and plotted, it woudl help.
From excel, you can copy the chart to powerpoint (use paste special, windows picture metafile) and then save as jpeg.
As I understand, both the 3.3 and HO deliver more in lower freq and with turbo dig even deeper.
Thanks,
-Jai

This is probably a question for Peter or Dr. Hsu,

To my knowledge no detailed measurments are available on the internet for the HSU HO w/ turbo and HSU 3.3 w/turbo. When I say detailed, I mean something along the lines of what Ilkka has done. Craig's measurments are useful too but I need more details. Ilkka's measurements of the 3.2 especially the Max SPL at the threshold of compression and the max spl achievable with compression are in the attachment here. Please take a good look at it and if you can shed some light into what can be expected from the Ho w/turbo and the 3.3 w/turbo, that would be great. In room measurments will not be a good idea to factor in here.

If the attached chart's values are keyed into excel and then based on knowledge if the expected performance of the two other subs can be posted and plotted, it woudl help.
From excel, you can copy the chart to powerpoint (use paste special, windows picture metafile) and then save as jpeg.
As I understand, both the 3.3 and HO deliver more in lower freq and with turbo dig even deeper.
Thanks,
-Jai

Jai ... Once we get into warm weather, a bunch of subs are going outside for a serious measuring session.

Craig,
That would be awesome.

I am struggling with Howard Ferstler's review on the HSU 3.3 with turbo. There he mentions measuring 114dB at 30Hz. He also talks about the 3.1 hitting 112dB. The measurments were 17ft (about 5m) away in a 3400 cu ft room. Ilkka's measurments were at 2m. The max he measured was 102dB. Accounting for about 6dB loss (moving from 2m to 5m) this translates to 96dB at 30Hz. Maybe he could have pushed it beyond, but appears not, since he stops at the point the sub can't go any further.
The 3.2 should be equal or slightly better than the 3.1. So the 3.1 would have also hit around 96dB. How could it have ever reached 112dB?? A room gain of 16dB?
What am I missing? Any errors in my calculation?
Puzzled.

I heard through PM from a very reliable source that 10-12dB room/boundary gain is possible. Also the SPL to distance loss will be much lesser indoors.
So Ferstler's number makes sense.

Craig,
That would be awesome.

I am struggling with Howard Ferstler's review on the HSU 3.3 with turbo. There he mentions measuring 114dB at 30Hz. He also talks about the 3.1 hitting 112dB. The measurments were 17ft (about 5m) away in a 3400 cu ft room. Ilkka's measurments were at 2m. The max he measured was 102dB. Accounting for about 6dB loss (moving from 2m to 5m) this translates to 96dB at 30Hz. Maybe he could have pushed it beyond, but appears not, since he stops at the point the sub can't go any further.
The 3.2 should be equal or slightly better than the 3.1. So the 3.1 would have also hit around 96dB. How could it have ever reached 112dB?? A room gain of 16dB?
What am I missing? Any errors in my calculation?
Puzzled.

I have hard time understanding this post! Did Illka test any sub in Room? What is the 3.1 (am I missing something?) :confused: ... Moving from 2m to 5m is bit more than 6 db loss (anechoic), but in room, it will all depend on room interaction with location where you may find some frequencies build up or cancel... so I'm not sure :confused: I don't understand do you mean the HSU VTF3MK3 when you say 3.1 :confused: Pls elaborate.

Thanks

No the tests were all done outside. 3.1 is VTF3 MK 1. I think it is an older model. I don't know much about HSU subs, just learning. Yes, the loss is a bit more than 6dB, I approximated.

No the tests were all done outside. 3.1 is VTF3 MK 1. I think it is an older model. I don't know much about HSU subs, just learning. Yes, the loss is a bit more than 6dB, I approximated.

Thanks for your kind reply. Do you have a link for this test pls?

Here (http://www.hometheatershack.com/forums/subwoofer-tests/) you go.

This is what I thought. I know very well this link and know that the MK2 was tested and not the MK1. Then I still don't understand something: you comparing Festler result with the MK3 at 20 Hz to Ilka's MK2 test at 30 Hz? Or is it both 30 Hz, or 20 Hz? Moreover, when you say the MK1 is slightly better than the MK2.... I think you mean the MK3 is slightly better than the MK2....

OK! Look I think I understood what you mean, (IMO)16 db gain is quite possible in moderately sized rooms with concrete walls..., counting roughly 9-10 db boundry gain + 12 db/octave theoretical (which in reality may be less... anywhere from 6 to 12 db/octave) below 30 Hz.... So at 20 Hz it makes approx 9-10 db + 3-7 db could be anywhere from 11 to 17 db...

If Craigsub could give us his opinion it would be great!

Thanks

This is what I thought. I know very well this link and know that the MK2 was tested and not the MK1. Then I still don't understand something: you comparing Festler result with the MK3 at 20 Hz to Ilka's MK2 test at 30 Hz? Or is it both 30 Hz, or 20 Hz? Moreover, when you say the MK1 is slightly better than the MK2.... I think you mean the MK3 is slightly better than the MK2....

OK! Look I think I understood what you mean, (IMO)16 db gain is quite possible in moderately sized rooms with concrete walls..., counting roughly 9-10 db boundry gain + 12 db/octave theoretical (which in reality may be less... anywhere from 6 to 12 db/octave) below 30 Hz.... So at 20 Hz it makes approx 9-10 db + 3-7 db could be anywhere from 11 to 17 db...

If Craigsub could give us his opinion it would be great!

Thanks
I think I said "The 3.2 should be equal or slightly better than the 3.1", so I mean VTF3 MK2 better than VTF3 MK1.
Terminology.

VTF3 MK2 = 3.2
VTF3 MK1 = 3.1

I sometimes tend to be cryptic when I type since I have so much to say and my mind is going exponentially faster than I can type. Multi-tasking several different things at one time, at home now doing home chores, coming here in and out whenever I can, working round the clock. Good thing is making progress on all fronts but this forum thing is going to stop once I finish my upgrade and you guys are going to think I dropped out of the planet :) and then I will be back who knows when!

I plotted the charts for the extrapolation thread while watching superbowl. Now I know this would be heresy :D.

Jai ... Once we get into warm weather, a bunch of subs are going outside for a serious measuring session.

:cool:

...once I finish my upgrade...

Jai, what subs are you considering for your upgrade? Are you thinking of doing dual co-located units?

That new 13" Ultra is going to be very intriguing, as are the new promised killers from TC Audio...

Jai, what subs are you considering for your upgrade? Are you thinking of doing dual co-located units?

That new 13" Ultra is going to be very intriguing, as are the new promised killers from TC Audio...
I haven't made up my mind yet. What would be an upgrade from a Danley DTS-20? :). In the price range I am looking at, it may not be an upgrade but a change. Yes, I am thinking of at least a dual or trio/quarted co-located subs. The DTS-20 thing is a long story. I will start another thread on that once I hear more from Danley Labs. They are still working on it.

There is no easy way to translate indoor numbers to outdoor ones. You have standing waves to deal with as well. When looking at indoor measurements, I would say you can only compare the measurements done by that reviewer in that room. If the same reviewer measures 8 dB higher for one sub compared to another, then that sub has 8 dB more output. You cannot take absolute numbers measured by one reviewer to the absolute numbers measured by another reviewer.

Dr. Hsu,
What a pleasant surprise. We are honored by your presence here!! Yes, I agree about indoor measurments. What are you thoughts about outdoor measurements though?
For example Ilkka's measurements (http://www.hometheatershack.com/forums/subwoofer-tests/971-finnish-subwoofer-tests-explained.html). By far, those are one of the most comprehensive and thorough measurments I have seen to date on the internet.
Again, welcome to the forums.
-Jai

Dr. Hsu,
w.r.t the data presented in my first post in this thread for the VTF3 MK II, what kind of Max SPL can we expect from the HSU VTF3 MKIII and HSU HO with turbo?
Thanks,
-Jai

Dr. Hsu,
w.r.t the data presented in my first post in this thread for the VTF3 MK II, what kind of Max SPL can we expect from the HSU VTF3 MKIII and HSU HO with turbo?
Thanks,
-Jai

Very good question. I hope to have the opinion of Dr. HSU :)

Thank you. I hope to visit this website when I have the time. His measurements are quite comprehensive, but, correct me if I am wrong, does not address the issue of port noise. Port noise will probably stay a subjective criteria.

Dr. Hsu,
I think the spectral contamination results try to capture port noise, driver motor noise and panel vibrations. Yes, this could get subjective. I simply paid more attention to when the compression begins also keeping THD in mind.
-Jai

I wonder when we will get an answer for this question. Even some ball park number will be useful.

I have a feeling that's not the real Dr. Hsu...

I have a feeling that's not the real Dr. Hsu...
That would suck big time :mad: :mad: :mad:
We need to find out.

That would suck big time :mad: :mad: :mad:
We need to find out.

Oh, that's probably the real Dr. Hsu :) Short, technical responses with no flowery embellishments? That's him :)

I had the opportunity to talk to him once on the phone. A very pleasant also sharp gentlman. I thought of calling him and finding out but didn't want to bother him with this.
I think we just have to wait and see.

I bet he gets called a lot with questions like, "where do I plug my subwoofer into my receiver? I put the three prong plug from the sub into the outlet on my receiver, but I'm not getting any sound....."

I'm sure he won't mind a few questions... ;)

I heard through PM from a very reliable source that 10-12dB room/boundary gain is possible. Also the SPL to distance loss will be much lesser indoors.
So Ferstler's number makes sense.

Being retired and looking for something to do via a Google search, I just stumbled onto this thread, and thanks for the comment.

The VTF-3, with the turbo extender, is one heck of a subwoofer and can match just about anything else available in a room that is not airplane-hanger in size. However, the non-turbo version (the supplied test sample of which I continue to use in my smaller AV system) is more than adequate for sane listening-level use. While it has greater measured distortion than, say, a Velodyne servo model, in terms of practical performance the Hsu is absolutely as good. Ditto for the similarly priced SVS models.

People make too much of a big deal out of which sub plays loudest, or even goes decently below 20 Hz the best. Many models by Hsu, SVS, Paradigm, Velodyne, and I suppose a few others can do this just fine, and it makes no sense at all to get into a series of twists about one sub being able to play maybe 2 dB louder than another at 20 Hz, when both can rattle the windows and play loud enough to do justice to any movie soundtrack or music source listened to with a properly equalized sub-sat system response curve.

Sure, some subs are just not all that good (although I never have heard a Hsu or SVS model that did not do justice at its price point), but in most cases, at least with the brands mentioned specifically above, you get what you pay for, and if you pay a reasonable amount you will get all the low bass you should need, unless you are some kind of insane gear head who wants bass louder, thicker, and boomier than any live music ensemble could generate or than any top-tier movie palace could produce.

Howard Ferstler

Howard, this post is over 3 years old!

Bill