My turbocharger is here =)

[jwill242004]

I recieved the turbocharger for my VTF3MK3 today and I will hook it up when I get home from work and post my thoughts.

Just a note:

I sent an email to HSU tech support regarding a faulty sub cable that I ordered from them, and never recieved an email back. To my surprise, HSU provided another sub cable free of charge and stuffed it inside of my sealed turbocharger box. Hows that for customer service!

[DNelms]

And you though no one was listening to you.......:rolleyes:

[jwill242004]

I know you guys are listening

[lradden]

Yep we're here how do you like it compared to not using it?

[Pete_Hsu]

jwill, we are all looking forward to your initial impressions!

[jwill242004]

To be honest, I am not as happy with the turbo as I thought I would be. The turbo has completely changed the sound of the sub IMO. I originally preferred the sound of the sub in max output mode with both ports open. With the turbo installed (which was a breeze by the way) and both ports open set to max extension mode, I find that the sub seems to be much more mellow with all mid to upper frequency bass. Low bass does seem to be a little cleaner though. A good way to describe the difference in sound would be to cover the sub with no turbo with a blanket, and listen. This is the best way I can describe it. If you did this low bass wouldnt be affected much but the impact of mid and high bass might be reduced slightly.

With Music:

I did kind of an A/B test with and without the turbo. I picked a CD that I was familiar with that had some really good low extension as well as tight kick drums and double bass kicks, something good all around for bass. I played it back over and over with the turbo installed, and then took it off, flipped the switch to max output mode and replayed the same track over and over. The difference was very significant. It sounds like a completely different sub with the turbo on. Next I popped in the test CD that came with the sub and played the Pipe Organ Track1. I figured that this is what the turbo was meant for anyway right? Again I didnt notice all that much difference in performance between my previous listening test without the turbo, although port noise was reduced some. Overall you can definately tell that the sub plays louder on the bass below 35 or 40 hz, but its not a complete difference that I was expecting. I had a friend over and he completely agreed. I prefer this sub without the turbo for music, set with both ports open in max output mode.

With Movies:

I did the same A/B type test with Star Wars Episode 2 and LOTR 3. This is where the turbo can add a little oomph to your setup. The opening scene in Attack of the clones when the ship comes in for a landing was intense with the turbo, but it was intense before also. This scene just seemed to play louder with the turbo installed. I found this to be the case with almost every scene I played with the turbo on. No improvement unless you dip into some extremely low bass. I know thats what the turbo was meant to do anyway so all in all I am pleased. I just didnt expect the bass that you get 95% of the time to be reduced like it was ( so this brings disappointment right up to the top of my priority list)

I have made the decision to remove the turbo if when I'm wanting to rock out to music. Put it on when I am watching a movie. Not a big deal since the install of the turbo is extremely easy. Those of you that are into rock, metal, or any kind of music for that fact, will probably prefer sound with no turbo. If this sub is used strictly for HT I dont think you will ever need to remove the turbo.

More opinions to come im sure.

[JHixson]

JWill,

Interesting post I have an HO with turbo and I must say I really did not experiment much with the sub without the turbo. I think what you are stating is true but I have a question. Did you recalibrate the sub when you added and removed the turbo, the upper bass is probably hotter in max extension mode and a part of your experience may be that the sub is just playng louder at those frequencies.

I use an SMS-1 and in my room have to boost the upper bass to get a flat response with turbo and am hoping to soon have the MBM in hand to play with.

[jwill242004]

No I didnt recalibrate with turbo installed. I originally did no calibration of this sub, just audibly with the recievers test tones. I found that I preferred the sub louder than the rest of the speakers. Just the other day I finally calibrated with a meter to 80db and still preferred the sub to play higher than the rest. You should remove the turbo on your HO and do a little comparison, you will be surprised at the difference in sound between max output mode and max extension mode, even without the turbo. How large is your room?? If I do have the sub running hot with the turbo it will affect output in mid to upper bass frequencies??

[JHixson]

I run mine a little hot also, my thought was that it was louder in MAX output mode and if you ran it a little hotter in max extension with the turbo it may have minimized some of the differences. I may play with mine without the turbo this weekend just had surgery and can't play golf.

When I first used the SMS-1 my first thought was man does this sound different but one of the big issues was I had to use some cuts in the lower bass so when I bypasses the SMS-1 those frequencies were much hotter and gave me the impression of much more bass. Once I adjusted the SMS volume so the bypass and the EQed were the same there was still a difference but it was a good difference without the hot spots and dips in the bypassed signal.

It is amazing how much time we can waste playing with our toys.

[will95]

So, are you saying for music and most HT, skip the turbo? When you say more "mellow" with the turbo, does that mean less accuracy or weaker transient response on drums? I was about to place an order for the VTF-3 Mk3, so your further experience and feedback would be helpful. Based on what you have said so far, it sounds like your conclusion is - skip the turbo since it alters the overall sound, making it (at least to your ears) less musical and that the only thing missing is a little bit of very deep base volume.

[jwill242004]

No, I am saying for most music you will not need the turbo. I would recommend it for use with all Home Theater. You are misunderstanding me. what I found with music is that it didnt make much of a difference, and somewhat took away from the original sound I was getting from the sub when it was set to max output mode. Without the turbo set to max extension mode I still wasnt overall pleased with the sub when I first got it, which is why I kept it running in Max output mode and was amazed at its performance. Adding the turbo and keeping it in max extension mode gave me the same initial impressions as I had before I got the turbo. It just isnt as loud in Max Ext mode, thats all there is to it.

With the turbo added the bass didnt seem as tight, punchy and forceful as I would like it to be with bass drum kicks. I believe this is a direct result of the 18hz tune. I fixed this immediately by setting it to max output mode and the performance was nothing short of amazing. Now with the turbo I am forced to keep it in max ext mode and still feel like its lacking somewhat. It DOES NOT lack in low frequency extension however, and will absolutely smoke any sub out there in its price range in this regard.

I would recommend you to get the turbo for sure, just figure on using it on movies, and music that has some really low bass in the mix. Heck you might prefer the way the bass sounds with it installed all of the time, our ears are different bro!

[lradden]

To be honest, I am not as happy with the turbo as I thought I would be. The turbo has completely changed the sound of the sub IMO. I originally preferred the sound of the sub in max output mode with both ports open. With the turbo installed (which was a breeze by the way) and both ports open set to max extension mode, I find that the sub seems to be much more mellow with all mid to upper frequency bass. Low bass does seem to be a little cleaner though. A good way to describe the difference in sound would be to cover the sub with no turbo with a blanket, and listen. This is the best way I can describe it. If you did this low bass wouldnt be affected much but the impact of mid and high bass might be reduced slightly.
I did some graphs once of the HO with and without turbo to see if there was a change in the mid bass. I recalibrated the HO with and without turbo so it was an apples to apples comparison. If I didn't recalibrate I had a 3dB difference between with and without turbo.

Here's the graphs, as you can see when level matched the HO with and without turbo have pretty much the same mid bass. The graphs show how the turbo really allows the HO to leave the non turbo behind below 20Hz, other than that they are almost identical. These graphs are sub only no other speakers.
http://pages.cthome.net/lradden/ht/VTF-3%20HO%20Comparisons.htm

[will95]

No, I am saying for most music you will not need the turbo. I would recommend it for use with all Home Theater. You are misunderstanding me. what I found with music is that it didnt make much of a difference, and somewhat took away from the original sound I was getting from the sub when it was set to max output mode. Without the turbo set to max extension mode I still wasnt overall pleased with the sub when I first got it, which is why I kept it running in Max output mode and was amazed at its performance. Adding the turbo and keeping it in max extension mode gave me the same initial impressions as I had before I got the turbo. It just isnt as loud in Max Ext mode, thats all there is to it.

With the turbo added the bass didnt seem as tight, punchy and forceful as I would like it to be with bass drum kicks. I believe this is a direct result of the 18hz tune. I fixed this immediately by setting it to max output mode and the performance was nothing short of amazing. Now with the turbo I am forced to keep it in max ext mode and still feel like its lacking somewhat. It DOES NOT lack in low frequency extension however, and will absolutely smoke any sub out there in its price range in this regard.

I would recommend you to get the turbo for sure, just figure on using it on movies, and music that has some really low bass in the mix. Heck you might prefer the way the bass sounds with it installed all of the time, our ears are different bro!

jwill242004, thanks for the clarification.

The HO curves from lradden help. Don't really see any significant mid-bass difference. Its probably a very reasonable assumption that the VTF-3 Mk3 would have a similar result with versus without the turbo. For a calibrated set-up, the turbo doesn't appear to alter the mid-bass response at all.

[jwill242004]

in my room, mid and upper frequency bass notes sound very laid back when the turbo is installed. Much more so than they did without the turbo, even when it was set to max extension mode with no turbo.

[spyboy]

I did some graphs once of the HO with and without turbo to see if there was a change in the mid bass. I recalibrated the HO with and without turbo so it was an apples to apples comparison. If I didn't recalibrate I had a 3dB difference between with and without turbo.

Here's the graphs, as you can see when level matched the HO with and without turbo have pretty much the same mid bass. The graphs show how the turbo really allows the HO to leave the non turbo behind below 20Hz, other than that they are almost identical. These graphs are sub only no other speakers.
http://pages.cthome.net/lradden/ht/VTF-3%20HO%20Comparisons.htm


Listen guys: lradden has this exactly correct...look closely at the bottom graph, there is almost no difference at all...people who really want to kick some butt get a pair of '3HOs and with or without Turbos they have every range of the bass spectrum in spades...jwill, don't know exactly what you are hearing, however, there is not 5 cents worth of difference in reality, of course, that is my humble opinion...with my 2 '3HOs even without Turbos i get an incredible amount of bass with the X-Over set to 80Hz...what do you have your X-Over set at?

keep in touch

[jwill242004]

I have my x-over set to 80hz. I'm sure Iradden is correct with his graph, Im not saying he isnt. What I am telling you is that there is a definite audible difference in the bass that is played with and without the turbo. I have had 2 more people listen and we all are in agreement. In fact the last 2 people I have let listen felt the sub sounded better overall without the turbo and set into max output mode, just like I had it before. Im not knocking the turbo, or what it is capable of doing, or the thought behind it. It all makes perfect sense. It is good for just what it says on the box, doubles the amount of air moved in low frequency bass. This is a great thought, however in my room and in my setup this is relavent about 2 % of the time.

[Pete_Hsu]

A couple points I would like to make here. First, I feel that if mid-bass output is higher relative to low bass output before the onset of output compression, then the subwoofer may sound more punchy. That is one of the advantages of maximum output mode, in that it tends to have a punchier sound, since the ratio of mid-to-deep bass output is higher than extended bass mode. Second, at some frequencies (say 25Hz in this case), distortion will be lower in maximum output mode vs extended bass mode. Note that the higher the box is tuned, the more efficient it will be at moving air over the most common bass frequencies at and above 25Hz. Clearly in the deepest bass (at and below 20Hz), turbocharger will make a very big difference. The tradeoff between the variable tuning modes is maximum output/widest dynamic range vs. maximum extension/deepest bass.

The nice thing about the MBM-12 is that is allows you to have your cake and eat it too. One can run a VTF-3 HO (or VTF-3 Mk3) with turbocharger to excel in the deeper bass, while having huge headroom in the mid/upper bass as well.

[lradden]

Guys I should also mention that I've been building a house curve in with my BFD so that's why the SPL rises as the frequency gets lower in the graphs. I added a fourth graph at the bottom of the page that shows performance down to 12Hz instead of just 16Hz. The 16Hz turbo has about a 6-7 dB advantage below 16Hz down to 12Hz over the 16Hz non turbo. For me this makes the turbo well work it and shows how the turbo in my room is clearly providing the extra headroom I want. to get this kind of extra headroom I'd need a second HO, but the turbo gives the extra output for $200 or $100 if ordered with a sub.http://pages.cthome.net/lradden/ht/VTF-3%20HO%20Comparisons.htm

The feeling with the turbo is more tactile, I'm guessing because there's a lot more air moving with two ports open vs. one in 16Hz mode. The other thing is how effortlessly the sub plays with the turbo below 20Hz. Graphs just can't show this but even though they seem close the turbo just makes the sub seem to be loafing at volumes a lot higher than the graphs show. The SPL in the graphs are a peice of cake for the HO with or without the turbo, but at higher volumes your ears and butt can easily hear and feel the turbo is superior to the non turbo. The turbo just sounds cleaner at higher volumes. Your ears just tell so much more than any graph can show.

[JimLely]

Could you please clarify what these graphs represent. Are these curves taken at the threshold of compression at a particular frequency? (frequency?@??Hx)

Thanks,

Jim

[lradden]

Could you please clarify what these graphs represent. Are these curves taken at the threshold of compression at a particular frequency?

Thanks,

Jim

Hi Jim,
No they are not at the threshold of compression at a particular frequency. The original poster had stated that he felt in his room there seemed to be less mid bass with the turbo attached. All they show is how similar the response is with and without the turbo in "my room". The graphs show absolutely nothing about compression or max output at any frequency.

All I did was calibrate with AVIA, I set my pre amp's MV to -15, removed all speakers from my sytsem through the pre amp's menu so that only the sub was playing and took the measurements with the turbo. Then I repeated the process starting with the AVIA calibration, but this time without the turbo.

All I was trying to figure out is whether or not removing the turbo would result in an increase or decrease in bass at any frequency when level matched. I had already performed the first three graphs earleir in the week and then when I saw this post I figured I'd post them since my findings showed the mid bass at a certain MV (-15) setting on my system did not show a reduction in mid bass with the turbo.

There very well could be an increase or decrease at higher or lower SPL levers I don't know, but at this SPL in my room there isn't. The graphs have nothing to do with max output or compression in anyway since at the level I tested at the sub was just loafing with or without the turbo and had plenty left in the tank.

The last graph just shows the benefit of the turbo in my room below 16Hz. Really if you look at the graphs they show that in my room there is no penalty for adding the turbo in mid bass at this SPL at all, but there is a benefit to having it below 16Hz. Of couse graphs say nothing about sound and to me graphs are fun, but trust your ears. Mine say to leave the turbo on, it's a great addition to the sub and doesn't effect the sound in a negative way at all in my room.

[SeattleDucks]

As Peter mentioned, max extension vs. max ouput mode involves an inevitable tradeoff. My home theater is open to another room and totals 6900 cu. ft. and yet I am simply AMAZED at the dynamics of my single VTF-3 MK3 in max output mode (curently placed nearfield which gives very big grins :D).

Switching to max extension does provide a bit more bass below 22hz and the Turbo really helps in this mode to allow higher output at these deepest frequencies, but after much listening to both I'm preferring the max output mode (no Turbo) for everything, especially movies, because the dynamic headroom in the mid/upper bass adds tremendously to explosive LFE effects. My room is tough to drive and if it were not as large I may very well have preferred the Turbo with max extension.

After moving around and measuring my sub in a dozen different locations, and having recently become addicted to the kick-in-the-pants visceral impact of nearfield placement, I am now seeing Dr. Hsu's wisdom in creating the MBM-12 for nearfield slam coupled with a Turbo-charged 3mk3 or 3HO near a corner for max deep extension...hmm, when it comes to the wife is it easier to ask for permission, or forgiveness?? ;) "Honey, I am so sorry I bought that MBM-12 without discussing it with you first, I am a very bad man - how can I make it up to you?" :D

[jwill242004]

Seattle,

I am in the same position as you. My room is open to another room and my square footage is around the same as yours. I prefer the max output mode with no turbo also. As you said, the MBM nearfield is a great fit with the addition of the turbo, if you want to spend that extra money. For those on a budget, I feel you can get plenty of bass without the turbo and will be satisfied without it.

I am going to be completely honest with you guys, as I am sure you would expect nothing less. As you all know I am a big fan of my new sub and I will never purchase another brand of subwoofer. However.....if I didnt have to pay the shipping charge to send the turbo back, and still get a full refund, I would do it. I just dont think it adds many benefits to the subwoofer. I feel the turbo is only a good addition if you plan on adding the mid bass unit also. Sacraficing mid and high bass output to get a little more low extension is not worth it IMHO. With the MK3 you get plenty of low extension anyway. You can display all the graphs you want showing that the mid and higher frequency bass doesnt change, I can tell you it DOES change. There is an immediate difference in sound when you add the turbo.

The variable tuning mode is a great idea, but when you add the turbo you are basically turning your sub into a Single tuning mode sub, and you are forced to leave the sub in max extension mode. Which means you get that max extension sound, which I initially did not prefer. You do not have a choice of modes anymore (if you choose to leave the turbo on).

[Pete_Hsu]

jwill, technically you can run the subwoofer with maximum output (22Hz) mode set on the amplifier, and turbocharger installed (or with one port plugged). This will give an overdamped response. On the other hand, it would not be a good idea to run the subwoofer with both ports open (no turbo) and extended bass mode (16Hz) set on the amplifier.

It seems that you just prefer the maximum output mode (vs extended bass mode via port plug or via turbocharger), and that is not surprising, because the subwoofer is very strong even down to 20Hz in maximum output mode. You should try selling the turbocharger, you may even make some money in the process!

[jwill242004]

I do not plan on selling it. As I said before, I will continue to use it during movies, and take it off for music listening. It has its benefits, but overall I think it performs best without it, well 98% of the time.

[SeattleDucks]

jwill, I understand where you are coming from - the Turbo is not the perfect fit for everyone depending on personal preferences and room size. I do still think it is a great economical way to extend the ouput of the very low frequencies for many users, but like you I prefer the amazingly dynamic max output mode of my -3MK3. Tonight I had my neighbors over for drinks and a kick-butt demo of the home theater, and they were simply floored by the performance of the -3MK3 (along with the Ascend speakers) on selected scenes from War Of The Worlds, Master And Commander, Finding Nemo, Flight Of The Phoenix, and Jurassic Park III. I will continue to buy them off with beer & pizza in order to maintain their tolerance for the rumbles they hear in their own home from my mighty HSU sub :D

[rman222]

Peter,
You indicated above that technically you can run the VTF3MKIII in the max output mode with the turbo installed, but will get an overdamped response. What does that mean and what would the sonic and other effects be?
Thanks,
Joe H

[SeattleDucks]

Today I was watching the train arrival scene in The Polar Express with my VTF-3 MK3 in max output mode, and it did not seem to have the full weight and realism of an actual train even though it was plenty powerful. So I switched to maximum extension mode and hooked up the Turbo, recalibrated (needed to up the sub volume w/max ext.), and watched the scene again, and this time...WOW! It felt like an actual steam train had just pulled up to my family room, with an amazing sense of realism and naturalness. Surprising what those few extra frequencies from 16hz to 20hz can do when the source material calls for it.

I'm going to watch several more demanding scenes from a variety of DVDs with the Turbo on to see which ones work best in max extension mode. I love how easy the Turbo is to take on and off so I can customize my HT sound to suit the movie or the mood. It definitely makes a positive difference when you compensate with increased sub volume when going with Turbo/max extension mode.

[jwill242004]

how much of an increase in volume are we talking about here. Increasing the volume on the reciever or gain control on the amp?

[lradden]

Today I was watching the train arrival scene in The Polar Express with my VTF-3 MK3 in max output mode, and it did not seem to have the full weight and realism of an actual train even though it was plenty powerful. So I switched to maximum extension mode and hooked up the Turbo, recalibrated (needed to up the sub volume w/max ext.), and watched the scene again, and this time...WOW! It felt like an actual steam train had just pulled up to my family room, with an amazing sense of realism and naturalness. Surprising what those few extra frequencies from 16hz to 20hz can do when the source material calls for it.This is why I love the turbo. It's also why I say the graphs I posted may not show a difference with and without the turbo, but the tactile feeling with the turbo make a a hugh difference. It's also why I say graphs can’t make up for the seat of the pants and listening experience, the turbo just moves so much air and pressurizes the room so much more than running without it. Adding the turbo really does turn it into a different sub.

[jwill242004]

Im hear all this, but now Im thinking im not getting this effect simply because i am running it at the same volume with and without the turbo. Do I need to crank up the volume on the sub to get this feeing. If so, then whats the real benefit, wouldnt I just be able to crank it up with the turbo off and get the same increase in bass? If you have to increase the volume level for the turbo to perform doesnt that defeat the purpose?

[RatFarm]

Food for thought: The ports and turbo don't really come into play until the port tuning frequency is met. At that frequency and lower, the ports (turbo) are moving air (literally too). With the addition of the turbo, the port orientation changes and so the room reflections and tuning frequency change also, assuming you run with the max extension mode. It seems that the adjustment to the subs volume control is to offset the loss of room reflection (where in the case the non-turbo'd ports were firing into a wall previously). It is unlikely that the turbo'd ports are firing into a wall unless the whole front of the sub is facing a wall. Whether the turbo is installed or not, the mid-bass frequency is mostly eminating from the woofer itself.

So I guess the bottom line is that since the port length, port orientation (direction) and room reflection pattern changes with the turbo, a recalibration of the volume and crossover point is needed to adjust for the differences. You also might consider lowering the low freq crossover with your main L/R speakers to bring back some of that punch if your speakers are capable.

Hope this makes sense.

[lradden]

Absolutey when I ran the graphs with and without the turbo I had to re-calibrated because there was about a 2dB difference.

[SeattleDucks]

how much of an increase in volume are we talking about here. Increasing the volume on the reciever or gain control on the amp?

I like to keep my receiver trim at -5 and so I increase the gain on the sub when recalibrating. In my room it calibrates properly in max output mode with the gain control set at 9 o'clock, and with max extension/Turbo mode my measurments definitely show reduced volume by about 3db or so and I just increase the sub gain to about 9:30-ish.

It may be hard for you to turn yours up much more because if I recall you are running your sub pretty hot with your gain control about halfway up, correct? At some point you are simply going to run out of amplifier headroom.

[SeattleDucks]

Food for thought: The ports and turbo don't really come into play until the port tuning frequency is met. At that frequency and lower, the ports (turbo) are moving air (literally too). With the addition of the turbo, the port orientation changes and so the room reflections and tuning frequency change also, assuming you run with the max extension mode. It seems that the adjustment to the subs volume control is to offset the loss of room reflection (where in the case the non-turbo'd ports were firing into a wall previously). It is unlikely that the turbo'd ports are firing into a wall unless the whole front of the sub is facing a wall. Whether the turbo is installed or not, the mid-bass frequency is mostly eminating from the woofer itself.

So I guess the bottom line is that since the port length, port orientation (direction) and room reflection pattern changes with the turbo, a recalibration of the volume and crossover point is needed to adjust for the differences. You also might consider lowering the low freq crossover with your main L/R speakers to bring back some of that punch if your speakers are capable.

Hope this makes sense.

Good points RatFarm. Getting the very best fine-tuned sound does get complicated at times due to placement/room interactions and for me requires a ton of experimenting, measuring, and listening.

[SeattleDucks]

Im hear all this, but now Im thinking im not getting this effect simply because i am running it at the same volume with and without the turbo. Do I need to crank up the volume on the sub to get this feeing. If so, then whats the real benefit, wouldnt I just be able to crank it up with the turbo off and get the same increase in bass? If you have to increase the volume level for the turbo to perform doesnt that defeat the purpose?

The benefit of the Turbo only comes into play when using max extenson mode, allowing higher volume at the deepest frequnces under 22hz than what you would achieve with one port plugged, and whether with or without Turbo the max extension mode (on any sub) always comes at the expense of some mid-bass dynamic impact. It's an inevitable tradeoff, but so cool that HSU gives us the ability to choose for ourselves based on personal preference.