Hsu Research VTF-3 HO Turbo & MBM-12

mike c said:

i hope those ports bend inside.

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I know the EP500 doesn't. I hope they do.

SheepStar

But isn't the point of the MBM-12's that you have less distortion in the mid-bass region (also less intermodulation distortion) as well as greater output compared to a normal subwoofer ?

Isn't there a more linear transition between the low bass and the mid-bass ? Besides, you are allowing the subwoofer to handle the low range as it does best and the MBM-12 can handle the mid-bass region far cleaner and with more headroom than most subwoofers.

Aren't those advantages ?

--Regards,

Vaughan Odendaa said:

But isn't the point of the MBM-12's that you have less distortion in the mid-bass region (also less intermodulation distortion) as well as greater output compared to a normal subwoofer ?

Isn't there a more linear transition between the low bass and the mid-bass ? Besides, you are allowing the subwoofer to handle the low range as it does best and the MBM-12 can handle the mid-bass region far cleaner and with more headroom than most subwoofers.

Aren't those advantages ?

--Regards,

Click to expand...

The amount of distortion produced by a decent subwoofer in the mid bass region is already inaudible. You gain nothing. What happens is you have to blend 2 "bass speakers" and make sure they play well together. You might as well get a good EQ and 2 good subwoofers (minimum). You also don't get the added output everywhere. As a matter of fact, by playing the subwoofer and MBM in different frequency ranges, you really don't gain any headroom.

SheepStar

Sheep said:

As a matter of fact, by playing the subwoofer and MBM in different frequency ranges, you really don't gain any headroom.

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Why ? What about improving the speakers mid-bass support ? The MBM is more efficient in the range that it is voicing. It can generate high output levels within the 50-100 hz region than many subwoofers.

Surely utilizing the MBM for proper mid-bass support would allow the main subwoofers to concentrate more on the low stuff ? The main speakers should have even more headroom as they aren't voicing mid-bass that they can't reproduce at high levels properly.

Afterall, isn't the MBM supposed to be very efficient within the mid-bass range. If it isn't more linear and more accurate within that range then what is the point ? I mean, why would HSU bring out a device that was not beneficial in any way ?

I don't own any HSU gear but I can't believe that they would bring some product to market that had no merit whatsoever. To make the claim that there won't be any benefits is just very short-sighted to me.

--Regards,

I won't say the MBM really causes major enhancements or improvements to bass response. But because it's located right behind my seating position, it's far better than any tactile device (and cheaper).

But I'm overkilling anyway.

Vaughan Odendaa said:

Why ? What about improving the speakers mid-bass support ? The MBM is more efficient in the range that it is voicing. It can generate high output levels within the 50-100 hz region than many subwoofers.

Surely utilizing the MBM for proper mid-bass support would allow the main subwoofers to concentrate more on the low stuff ? The main speakers should have even more headroom as they aren't voicing mid-bass that they can't reproduce at high levels properly.

Afterall, isn't the MBM supposed to be very efficient within the mid-bass range. If it isn't more linear and more accurate within that range then what is the point ? I mean, why would HSU bring out a device that was not beneficial in any way ?

I don't own any HSU gear but I can't believe that they would bring some product to market that had no merit whatsoever. To make the claim that there won't be any benefits is just very short-sighted to me.

--Regards,

Click to expand...

So, what you're saying is the MBM can produce more SPL then a subwoofer can. Great, the whole idea is to have them play at the same level. Have you ever seen a subwoofer with a flat FR? It tends to play the mid bass, and deep bass, evenly.

The subwoofer isn't a processor, it doesn't perform 10 times better then you take away part of the frequency spectrum.

Last time I checked Main speakers should be crossed out at 80hz unless they can play to 20hz.

Why, do you keep bringing up efficiency. It doesn't matter if it can play at 150dB. The subwoofer can't, and you will have to tone it down to match. Then there is the problem of getting them to match up well. The distortion of a decent subwoofer is small enough not to make an audible difference between the 2.

Why would HSU make this? The same reason any company makes anything. MONEY.

SheepStar

Sheep,

For someone that has not even listened to my system, how come you try to pick it apart with your "This is better than that, and I've gained nothing by adding am MBM"?

From the HSU RESEARCH website:

The MBM-12 introduces our new patent pending concept of splitting up the bass frequencies. In most moderately sized rooms, mid-bass is best reproduced near the listener, while deep bass is best reproduced in a far corner. The mid bass module allows one to do optimally position the low frequencies nearby, for maximum impact.

The high direct to reflected sound ratio helps reduce room effects, gives excellent headroom (high SPL with low power since you are right next to the woofer), and low distortion. Low bass, on the other hand, is most efficiently reproduced when placed in a front corner.

Just like the VTF concept, a woofer optimized for low bass reproduction is not the best for mid to upper bass reproduction. A heavy cone is best for low bass, but that reduces the mid to upper bass efficiency. The MBM-12 woofer is optimized for mid to upper bass reproduction - a very light cone, low inductance voice coil, and a strong magnet yields extremely quick response with high efficiency. It demonstrates excellent micro-dynamics and an extremely wide dynamic range that no single subwoofer can provide.

Industry Reviews:

"One exhibitor, Hsu Research, had a setup that literally stunned me. In the back of the room where I was sitting, right behind my chair, was one of his new designs, called the MBM-12 Mid-Bass Module, that only reproduces the range from 50 to 150 Hz. He had it set for the range of 50 to 80 Hz. Since it is close to the sitting position, it does not have to be turned up very loud, although it has a 350 watt amplifier. The driver is lightweight, so it responds very quickly. The gunfight scene from Open Range was used for the demo, and the gunshots, because of that special woofer (of course, he had his regular subwoofers in there too, for the really low frequencies), sounded as close to real as I have ever heard in a home theater room. The effect stuck with me all afternoon. Anyway, if you ever have the chance to hear this demo at a local home theater show, be sure to sit in on it. Absolutely unbelievable! "
— Dr. John Johnson, Secrets of Home Theater and Hi Fidelity


Mr. Sheep, my system, using the equipment in my signature kicks butt. And the MBM-12 added even more once installed right by my listening position.

How you can say there is nothing gained, without having tested my system? How can you say I have "No more headroom" when my bass reproduction jumped from 500 watts from a single 12, to 850 watts with two 12's, easing the burdon of recreating the bottom end.

All my friends tend to agree that there is more punch with the MBM-12. Are they biased? No, because they don't have near the system I have, if any at all. But now you wonder, what do they know, they are just listeners, my point exactly.

And your eq suggestion justs adds distortion and less signal to noise ratio to a clean setup. Four subs would nice, but few on this board, and probably you also, can't even afford an VTF-3 HO Turbo, much less four.

From the HSU RESEARCH website:

The MBM-12 introduces our new patent pending concept of splitting up the bass frequencies. In most moderately sized rooms, mid-bass is best reproduced near the listener, while deep bass is best reproduced in a far corner. The mid bass module allows one to do optimally position the low frequencies nearby, for maximum impact.

The high direct to reflected sound ratio helps reduce room effects, gives excellent headroom (high SPL with low power since you are right next to the woofer), and low distortion. Low bass, on the other hand, is most efficiently reproduced when placed in a front corner.

Just like the VTF concept, a woofer optimized for low bass reproduction is not the best for mid to upper bass reproduction. A heavy cone is best for low bass, but that reduces the mid to upper bass efficiency. The MBM-12 woofer is optimized for mid to upper bass reproduction - a very light cone, low inductance voice coil, and a strong magnet yields extremely quick response with high efficiency. It demonstrates excellent micro-dynamics and an extremely wide dynamic range that no single subwoofer can provide.

Click to expand...

Thank you for quoting the manufacture of the product. Heaven forbid they'd have anything to gain from people buying an MBM.

Industry Reviews:

"One exhibitor, Hsu Research, had a setup that literally stunned me. In the back of the room where I was sitting, right behind my chair, was one of his new designs, called the MBM-12 Mid-Bass Module, that only reproduces the range from 50 to 150 Hz. He had it set for the range of 50 to 80 Hz. Since it is close to the sitting position, it does not have to be turned up very loud, although it has a 350 watt amplifier. The driver is lightweight, so it responds very quickly. The gunfight scene from Open Range was used for the demo, and the gunshots, because of that special woofer (of course, he had his regular subwoofers in there too, for the really low frequencies), sounded as close to real as I have ever heard in a home theater room. The effect stuck with me all afternoon. Anyway, if you ever have the chance to hear this demo at a local home theater show, be sure to sit in on it. Absolutely unbelievable! "
— Dr. John Johnson, Secrets of Home Theater and Hi Fidelity

Click to expand...

This guy is almost as valid as the manufacture! Do you know this publication supports break in?

Mr. Sheep, my system, using the equipment in my signature kicks butt. And the MBM-12 added even more once installed right by my listening position.

How you can say there is nothing gained, without having tested my system? How can you say I have "No more headroom" when my bass reproduction jumped from 500 watts from a single 12, to 850 watts with two 12's, easing the burdon of recreating the bottom end.

All my friends tend to agree that there is more punch with the MBM-12. Are they biased? No, because they don't have near the system I have, if any at all. But now you wonder, what do they know, they are just listeners, my point exactly.

And your eq suggestion justs adds distortion and less signal to noise ratio to a clean setup. Four subs would nice, but few on this board, and probably you also, can't even afford an VTF-3 HO Turbo, much less four.

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First of all, I'm not knocking your system, just the MBM. Secondly, in order to gain HEADROOM, you need to add to something. An MBM doesn't play the same frequencies as a subwoofer. It plays down to 50Hz, then the subwoofer takes over. Thusly, the subwoofer is not getting ANY assistance in it's job. I thought I explained this already..

Simple, you're friends either A.) Don't know squat about sound, or B.) Don't want to tell you that an MBM is a waste of 500 dollars. Plus, you can't accurately get an opinion from a listener unless it's blind. Otherwise bias comes into play.

I'm building my subwoofer, and if all goes well, I'll be building another one. I never said you NEED four. I said you NEED 2(4 being optimal).

Have a great day!
SheepStar

majorloser said:

I won't say the MBM really causes major enhancements or improvements to bass response. But because it's located right behind my seating position, it's far better than any tactile device (and cheaper).

But I'm overkilling anyway.

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i think this somes the thread up, it adds feel but doesnt give the sound a major improvement. This should be in the review section

Ric im sure your system is quite nice and i believe sheep was pointing out the correct technical aspects of the unit. IMO the good eq is a good idea. If it gives you satisfaction thats all that matters.

Sheep said:

So, what you're saying is the MBM can produce more SPL then a subwoofer can.

Click to expand...

Within the MBM's bandwidth, it can play back louder than many subwoofers. A 12" woofer cone tuned high with low mass should be able to produce some very high levels within the 50 hz and above region.

Great, the whole idea is to have them play at the same level. Have you ever seen a subwoofer with a flat FR? It tends to play the mid bass, and deep bass, evenly.

Click to expand...

Yes, I have. But one of the weaknesses of many subwoofers is the ability to play back mid-bass at high levels. Having a flat response curve means little when the curve changes dramatically at higher levels due to cone nonlinearities, power compression, etc.

One of the compromises made is to sacrifice output up high in order to gain greater output down low. Many speakers have a tough time trying to produce credible output in the mid-bass region. In this way, it would seem that utilizing one of these devices would lessen the burden on the main speakers and allow even more headroom for higher levels.

Why, do you keep bringing up efficiency.

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Because, like I said, within it's target bandwidth, it can play back louder with less distortion. The high efficiency, low mass (high Fs) driver should give very high output in the upper bass regions where it is tuned.

You simply will have more headroom available. For many people, I'm sure that would count as a benefit.

--Regards,

Vaughan Odendaa said:

But one of the weaknesses of many subwoofers is the ability to play back mid-bass at high levels. Having a flat response curve means little when the curve changes dramatically at higher levels due to cone nonlinearities, power compression, etc.

Click to expand...

i've heard of many subwoofers that have weaknesses at the LOW-bass areas. but to be weak in mid-bass simply means it's a crappy subwoofer in the first place OR too small for your listening tastes.

on a related note: from my playing around with subs, it would seem that the LOW-bass freqs. are actually the ones that shake the couch instead of the MID-bass.

Dance, Trance and AC/DC

I've had stereos in eight different houses, Army barracks, and apartments since I was 17, and am now 43. The equipment includes the good stuff from NAD, Denon, Yamaha, Emotiva, Sony, JBL, Boston Acoustics, Infinity, Aperion, Hsu, MK Sound.

None, NOT ONE was a recording studio. So throw all this horse S*** about flat freq. responce out the window, lets get real world here.

Sheep, chill brother man. We need not argue. We are all here in the pursuit of good audio.

Stereo Review taught me that the perfect amp was a straight wire with gain. And that in a 2.0 setup, 70% of amp power goes to freqs below 150 Hz. 70% is alot of amp, only leaving 30-50 watts for 150 hz. - 20,000 Hz. Lets ease the burdon by adding POWERED subs. Yeah, subs with an s.

Again, remember I'm old fart at 43, but now I can afford what I want. I still love AC/DC, ZZ Top, and anything resonable. the MBM-12 comes into its own when I play old 80's rock at above reference levels. The kick drum is awesome near field. I also have been turned onto modern Dance and Trance style music. Again, the near field beat is very pleasing with the MBM-12.

Did I get ripped off by Hsu Research? I don't think so, and I'm happy which is all that matters Find me an $1500.00 sub system that will out do my current setup, and I might get froggy. The Emotiva system is gaining popular attention from me. Almost as much power, 2 12's, room eq in amp, whats not to like.

Here is a pic of me typing in my hospitol bed. Yeah, I'm a C 3-4 Quadriplegic and type with my mouth. Back ground is my Amateur Station, K4SCI.



Radios without amp in pic. I've got WAY more money in Ham Radio than A/V. The transciever on the left is a $3000.00 Icom 756 Pro III



Here is the back wall, with the Aperion 532s as surrounds. TV looking object is an Apple iMac 24".



Couldn't find system pics, but will get some asap. Life is different in a chair, but except for the wire tangles, it ain't so damn bad

Gimpy Ric

AGREED!

The MBM-12 gives me a kick in the butt like no other sub or speaker I've ever had. Am I too am an old f@rt who's had my fair share of home and car audio gear

The MBM-12 might not be needed and probably is a waste in some people's eyes, but anybody I've had over to my house have said WOW! Mazer even commented how the MBM-12 blends well with music.

So I guess it ain't that bad. At least to my old ears.

Vaughan Odendaa said:

Not all of them can.

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then lets talk about the HSU research 12" subs. do they have "slam"?

removing the LOW bass from a sub will add HEADROOM to the MID bass.
removing MID bass from a CAPABLE sub will add but little headroom to the LOW bass.

subwoofer designers all say that if your sub is capable (like the HSU subs are) there's really no NEED to add headroom to the 50-80hz range.

i've used dual 15's as "mid bass modules" myself ... i did not experience any added headroom from the LOW bass from my 18" subwoofer.

Mike, perhaps I'm misunderstanding you, but I don't think I ever said that improving mid-bass levels would also improve deep bass levels. I am simply trying to say that, for many reasons, speakers don't generally perform too well in the mid-bass passband at very high levels.

I've tried to explain to Sheep that subwoofers generally trade-off upper bass efficiency for deeper bass output. By using a device more capable in that region, you should have better dynamics.

Taking the load off the speakers to concentrate on the "power band" (100 hz-400 hz) should result in better dynamics and less distortion. Using something like the MBM should result in more accurate bass within it's operating bandwidth. Afterall, it only works within that 50 hz -140 hz bandwidth.

--Regards,

Connors 40 Borg 30, out Duece Someone come to the net and put this away

OSHA Mandated Noise Maximums

OSHA Regulations 29 CFR 1910.95, Occupational Noise Exposure require employers to insure that employee noise exposure does not exceed specified limits for three different noise measurements. Noise level is measured in dB SPL ( “dB” stands for decibels, a logarithmic measurement; every increase of 20 dB raises sound pressure level [SPL] by ten times. 0 dB SPL is the threshold of hearing, 70 dB SPL is the approximate level of normal face to
face conversation). These regulations relate to:

• Impulse Noise - The highest maximum noise level permitted relates to noise of very short duration. These noises are described in the regulations as “impact” or “impulsive” noise. Impulsive noises are less than a few thousandths of a second in duration and repeat less than once a second. Examples are noises such as clicks or pops. OSHA regulations limit impulse noise to 140 dB SPL measured with a fast peak-hold sound level meter.

• Continuous Noise - The regulations set a lower limit for noises that are longer in duration than impact noise. Continuous noise is defined as noise extending over seconds, minutes or hours. Continuous noise must not exceed 115 dBA SPL when read on the slow average “A” scale of a sound level meter.

90 dB SPL - 8 hours
95 dB SPL - 4 hours
100 dB SPL - 2 hours
105 dB SPL - 1 hour
110 dB SPL - 30 mins.
115 dB SPL - 15 mins.
115 dB and higher - 0 mins. - (Pain Threshold) - In other words, instant permanent hearing damage.

• Eight-Hour Time-Weighted Average (“TWA”) - OSHA also requires employers to limit the average of all levels of impulsive and continuous noise to which an employee is exposed during an eight hour work day. Time weighting refers to the technique of giving louder noises greater weight in calculating the eight hour average. For example, a one hour exposure at 85 dBA is weighted the same as a two hour exposure at 80 dBA. An upper limit of 85 dBA for an eight-hour TWA is acceptable to OSHA. If employees are exposed to eight-hour TWAs between 85 and 90 dBA, OSHA requires employers to initiate a hearing conservation program which includes annual hearing tests. Eight-hour TWA levels higher than 90 dBA are unacceptable to OSHA.

majorloser said:

OSHA Regulations 29 CFR 1910.95, Occupational Noise Exposure require employers to insure that employee noise exposure does not exceed specified limits for three different noise measurements. Noise level is measured in dB SPL ( “dB” stands for decibels, a logarithmic measurement; every increase of 20 dB raises sound pressure level [SPL] by ten times. 0 dB SPL is the threshold of hearing, 70 dB SPL is the approximate level of normal face to
face conversation). These regulations relate to:

• Impulse Noise - The highest maximum noise level permitted relates to noise of very short duration. These noises are described in the regulations as “impact” or “impulsive” noise. Impulsive noises are less than a few thousandths of a second in duration and repeat less than once a second. Examples are noises such as clicks or pops. OSHA regulations limit impulse noise to 140 dB SPL measured with a fast peak-hold sound level meter.

• Continuous Noise - The regulations set a lower limit for noises that are longer in duration than impact noise. Continuous noise is defined as noise extending over seconds, minutes or hours. Continuous noise must not exceed 115 dBA SPL when read on the slow average “A” scale of a sound level meter.

90 dB SPL - 8 hours
95 dB SPL - 4 hours
100 dB SPL - 2 hours
105 dB SPL - 1 hour
110 dB SPL - 30 mins.
115 dB SPL - 15 mins.
115 dB and higher - 0 mins. - (Pain Threshold) - In other words, instant permanent hearing damage.

• Eight-Hour Time-Weighted Average (“TWA”) - OSHA also requires employers to limit the average of all levels of impulsive and continuous noise to which an employee is exposed during an eight hour work day. Time weighting refers to the technique of giving louder noises greater weight in calculating the eight hour average. For example, a one hour exposure at 85 dBA is weighted the same as a two hour exposure at 80 dBA. An upper limit of 85 dBA for an eight-hour TWA is acceptable to OSHA. If employees are exposed to eight-hour TWAs between 85 and 90 dBA, OSHA requires employers to initiate a hearing conservation program which includes annual hearing tests. Eight-hour TWA levels higher than 90 dBA are unacceptable to OSHA.

Click to expand...

Wow. I guess I better give up beans.

Wow, so my posts were deleted. Cool.

--Regards,

Majorloser, thanks for bringing up that article. Although it doesn't give you enough information. In my previous post that was deleted, I mentioned that our ears naturally taper off at low frequencies acting almost like a high-pass filter. Our sensitivity goes down as frequency is reduced.

What is important is that loudness varies with frequency. 120 dB's at 20 hz is not going to cause hearing damage whatsoever. 130 dB's at 20 hz shouldn't cause hearing damage either but the pressurization effect should be huge.

120 dB's at 100 hz is a different matter as our hearing is more sensitive as frequency increases. Even then, it depends on how long you expose yourself to that level. If it's for a brief second or two then I'm sure you'll be fine but for pro-longed periods, it can cause hearing damage. I don't consider 100 hz to be low in frequency although it does form part of the bass range.

Like I said to Sheep, I'm pretty confident that no subwoofer made my SVS, Epik or ED has the firepower to cause hearing damage within it's operating range unless you put your ear right next to the dustcap playing at full tilt for more than a few seconds.

--Regards,