HSU VTF-15H Subwoofer Review

[shadyJ]

Thank you for the reply Paul, it was very informative! That seems like odd behavior for a sub, but it looks like it was happening at high outputs at low frequencies. Am I to correct to think this? This sort of behavior doesn't happen in normal use, correct?

 

[Rogozhin]

I don't understand why you tested it on its side in the first place.

 

[templemaners]

I don't understand why you tested it on its side in the first place.

This article explains the how's and the why's of the testing methodology:

http://www.audioholics.com/education/loudspeaker-basics/2010-subwoofer-shootout

 

[Rogozhin]

This article explains the how's and the why's of the testing methodology:

http://www.audioholics.com/education/loudspeaker-basics/2010-subwoofer-shootout

Thanks for the link, I've read through it, but I'm unable to find a reason for testing the HSU on its side, were any of the other subs tested in a such a way, and if so was there a difference.

 

[TLS Guy]

Thanks for the link, I've read through it, but I'm unable to find a reason for testing the HSU on its side, were any of the other subs tested in a such a way, and if so was there a difference.

Read the review slower, with both eyes open. He explains the reason carefully. It has to do with mic port speaker distances.

 

[Rogozhin]

I found it, I had skipped that entire page by accident.

 

[TitanFan]

I am trying to understand these measurements and relate them to a real-world listening experience. Since I have never measured the output of a subwoofer, I'm not sure if an output of 100 dB is a realistic listening level or is that so loud that no one would ever turn it up that high? What would be considered a "normal" output range for a subwoofer? i.e. 80 dB (low) to 100 dB (high).

 

[Ron Temple]

I am trying to understand these measurements and relate them to a real-world listening experience. Since I have never measured the output of a subwoofer, I'm not sure if an output of 100 dB is a realistic listening level or is that so loud that no one would ever turn it up that high? What would be considered a "normal" output range for a subwoofer? i.e. 80 dB (low) to 100 dB (high).

That varies by the individual. Many watch movies at or near Dolby reference level. That's 85dbs average, but allowing for peaks of 20dbs in the main channels and 30dbs in the LFE channel or 105dbs for the main speakers and 115 for the sub at your listening position. That's quite loud for most of us, but as most LPs are approx 3 meters, it takes quite a bit of sub or subs to get there (along with a robust rig). I'd guess most listen anywhere from -15 to -5dbs from reference. So, since everytime you double the distance you lose 6dbs (from 1M to 2 it's -6, from 2M to 3M it's another -3dbs), these subs might or might not be reference level capable in a given room. If you never listen loud, it's a moot point. If you do, it's very germaine.

 

[TitanFan]

That varies by the individual. Many watch movies at or near Dolby reference level. That's 85dbs average, but allowing for peaks of 20dbs in the main channels and 30dbs in the LFE channel or 105dbs for the main speakers and 115 for the sub at your listening position. That's quite loud for most of us, but as most LPs are approx 3 meters, it takes quite a bit of sub or subs to get there (along with a robust rig). I'd guess most listen anywhere from -15 to -5dbs from reference. So, since everytime you double the distance you lose 6dbs (from 1M to 2 it's -6, from 2M to 3M it's another -3dbs), these subs might or might not be reference level capable in a given room. If you never listen loud, it's a moot point. If you do, it's very germaine.

I see, so -5dbs from reference (85dbs) would be a listening level of 80dbs. At a three meter listening position, the sub would need to output an additional 9dbs, so that would be 89dbs with peaks at 119dbs as a high level. A low level would then be about 10dbs lower, or 109dbs peak. Does that sound about right?

 

[sharkman]

I'll just interject one thing, hearing damage starts around the 85db level. I've measured music at that level and I find it too loud for my comfort. I do have some hearing damage though and occasionally suffer from tinnitus.

 

[GranteedEV]

I am trying to understand these measurements and relate them to a real-world listening experience. Since I have never measured the output of a subwoofer, I'm not sure if an output of 100 dB is a realistic listening level or is that so loud that no one would ever turn it up that high? What would be considered a "normal" output range for a subwoofer? i.e. 80 dB (low) to 100 dB (high).

I would like my sub to do around 107db @ 20hz at the seating positions with minimal distortion. this means roughly 8db below reference level average listening volume.

Keep in mind that these measurements are at 1m quasi anechoic.... dispersion loss, boundary gain, etc always come into play in room.

 

[Ron Temple]

I see, so -5dbs from reference (85dbs) would be a listening level of 80dbs. At a three meter listening position, the sub would need to output an additional 9dbs, so that would be 89dbs with peaks at 119dbs as a high level. A low level would then be about 10dbs lower, or 109dbs peak. Does that sound about right?

Figure it this way...you're listening at -5 from reference at your listening position at 80dbs average. Your sub will then be asked to output 110dbs when a 30db peak hits. The distance to your LP and the boundary reinforcement will vary depending on your room. You can calculate what you lose due to distance and gain due to room, but what's important it what the sub can do at your LP.

If you followed the shootout between the ED, Epik, CHT, Rythmik and Hsu subs put on by the brothers. All of the subs hit reference level at 8' from the LP on some material. Probably none of them could do it in that room at 3M. None of them could do it below 30hz from the charts I saw (in that room). All of them are excellent bargains in the sub $1000 range.

 

[billy p]

Figure it this way...you're listening at -5 from reference at your listening position at 80dbs average. Your sub will then be asked to output 110dbs when a 30db peak hits. The distance to your LP and the boundary reinforcement will vary depending on your room. You can calculate what you lose due to distance and gain due to room, but what's important it what the sub can do at your LP.

If you followed the shootout between the ED, Epik, CHT, Rythmik and Hsu subs put on by the brothers. All of the subs hit reference level at 8' from the LP on some material. Probably none of them could do it in that room at 3M. None of them could do it below 30hz from the charts I saw (in that room). All of them are excellent bargains in the sub $1000 range.

Ah...so that would explain why I only reach levels ~105-108 @ reference with my RS sitting about 11 ft away... And all along I thought my RS metre was faulty.....

 

[TitanFan]

Figure it this way...you're listening at -5 from reference at your listening position at 80dbs average. Your sub will then be asked to output 110dbs when a 30db peak hits. The distance to your LP and the boundary reinforcement will vary depending on your room. You can calculate what you lose due to distance and gain due to room, but what's important it what the sub can do at your LP.

If you followed the shootout between the ED, Epik, CHT, Rythmik and Hsu subs put on by the brothers. All of the subs hit reference level at 8' from the LP on some material. Probably none of them could do it in that room at 3M. None of them could do it below 30hz from the charts I saw (in that room). All of them are excellent bargains in the sub $1000 range.

That's a pretty clear explanation, thanks! Now I think I'll look into getting a SPL meter to measure my sub's output in my room. I'm sitting about 10 feet from the sub, but I expect I'll have some room gain, since my sub is in the corner.

I can see now why Audioholics measurement of 110 dB at 20Hz for the HSU VTF-15H is a little low. Ideally you would want it in the 115-120 dB range. Of course, if you don’t listen that loud or have nearfield placement and good room gain, then that output level should be just fine.

 

[cantonguy]

This comes off as a shot at Brian, correct me if I'm wrong. Your review of the Rythmik sub seemed more positive than any of the other subs, so this issue must not be a deal killer? If the issue is not there in real world use with music and home theater, what's the problem?

Maybe I missed it, but do the other subs have limiters?

Someone want to take a shot at addressing my earlier post?

 

[GranteedEV]

Someone want to take a shot at addressing my earlier post?

- He said the issue WAS there in real world listening - obviously his listening tests were done at full capability in a huge room at high spls so other people may not have triggered the limiter anyways in their listening.

The HSU is amplifier limited anyways, plus and the scenarios where it can be damaged were explored. Its response relies on EQing the transfer function relative to the port tuning and intended application rather than a 'limiter'.

the SVS was given such high praise partially BECAUSE of its digital limiting algorithms - that in essense it was a 'foolproof' sub which he couldnt get any issues out of. The raw performance (low distortion, high output, good damping, deep extension) was there too, but the DSP control over its behaviour was a huge part of why it was so commended. Older svs subs with bash amps did not use DSP btw...only the newer sledge based subs.

the funkywaves' electronics are a bit more barebones. If you want dsp you have to likely add it youself in the signal path. with that said it has insane power handling and linear excursion ability so the main thing would just be a well placed high pass filter below port tuning.

 

[AVRat]

To the top again

 

[TitanFan]

In reading the review one more time, I noticed the following statement:

"In our opinion, the best use of this subwoofer is with the Q control set to 0.3, both ports open, the EQ control (also called “operating mode”) set to “EQ2” ONLY."

I understand the recommendation for both ports open, but why the recommendation to set the Q control to 0.3?? Wouldn't a setting of 0.7 provide more output?

 

[sharkman]

I think you need to own one to get a good feel for what the Q control can do. I've tried the Q at .3 and .7 with the same passage of music and .3 gives tighter bass. From what I've read a lot of people are running it with one port plugged for the most bass extension, but I agree that for the most SPL you'd want to have both ports open.

These subs are pretty impressive. Very accurate for a ported sub and in my room (3400 cubic feet) I''m probably using only half of what this thing can do. In room I get a pretty flat response down to 16Hz, which rattles my pocket door! The more expensive subs in the shoot out must be absolute monsters if their GP measurements are any indication.

 

[Sputter]

VTF-15H x2
One Port open/Q=.7/EQ1 NF / EQ2 FF
Room is 4500 cu ft irregular. (retangular with one corner open to wetbar and workout alcove)