[DMurphy]

Nice.  I take it that it's the 70-20XR?

Yup.  The main advantage is that the wider ribbon allows for a lower crossover point--around 1900 Hz--which lets the ribbon do its thing over as wide a range as possible. 

[jsalk]

Nice.  I take it that it's the 70-20XR?

Yes.  When you purchase a manufacturing run, you get to specify the sensitivity values.

- Jim

[jtwrace]

Thank you gentlemen.   

[kenreau]

I don't want to run this thread off on a tangent, so feel free to move it as needed and/or if more appropriate in another location 

I've been following this thread for some time and marvel at the art & the science that goes into the creation of a s.o.t.a. speaker such as the HT4. 

Two things I am curious about;

1. The decision to use a TM two driver design vs. a MTM three driver design.  Is it simply to balance speaker size & cost over diminishing performance benefits (in my limited understanding) of the MTM?  At this sota design level, I see numerous examples of each and wonder why I see no apparent consensus.  I'm thinking of the Song Towers, top models of Wilsons, Hansen, Eggleston, YG Acoustics, Magico, Evolution Acoustics (MTMs) vs. (TM) Usher BE, smaller Wilsons, Magico, YG Acoustics, Kharma, etc. 

2. Midrange driver size.  The Accuton ~3"+/-4" diameter midrange.  Wow, that seems like a small diameter.  I understand the desirable benefits of speed and dispersion with smaller driver sizes, but how is the gap between the midranges lower end of ~300 Hz down to the woofer get filled?  There is obviously some juggling of sizes (maybe a 5"-6" midranges) with frequency ranges taking place.

Thanks
Kenreau

[DMurphy]

"1. The decision to use a MT driver design vs. a MTM three driver design.  Is it simply to balance speaker size & cost over diminishing performance benefits (in my limited understanding) of the MTM?  At this sota design level, I see numerous examples of each and wonder why I see no apparent consensus.  I'm thinking of the Song Towers, top models of Wilsons, Hansen, Eggleston, YG Acoustics, Magico, Evolution Acoustics (MTMs) vs. (TM) Usher BE, smaller Wilsons, Magico, YG Acoustics, Kharma, etc."

This really wasn't a close call.  One of the main advantages of an MTM configuration is added sensitivity overall and power handling in the bass.  But that only holds for a 2-way.   In a 3-way with one large woofer capable of plumbing the depths down to 19 Hz, the woofer sensitivity will establish the system sensitivity, and it will be quite low if the woofer can really deliver the bass goods (remember the Iron Law of bass).  So the added midrange senstitivity of an MTM would be completely wasted.  You would have to pad down the mids anyhow.  And the Accuton doesn't have to produce any low bass, so power handling isn't an issue either. 

"2. Midrange driver size.  The Accuton ~3"+/-4" diameter midrange.  Wow, that seems like a small diameter.  I understand the desirable benefits of speed and dispersion with smaller driver sizes, but how is the gap between the midranges lower end of ~300 Hz down to the woofer get filled?  There is obviously some juggling of sizes (maybe a 5"-6" midranges) with frequency ranges taking place."

The Fs (natural bass resonance)of the Accuton is 96 Hz.  It's crossed to the woofer at 350 Hz, so there is no hole in the response to fill.  The Accuton and the Big Hog woof blend together perfectly using 2nd order acoustic slopes.  And by the time the Accuton hits its Fs, it's 24 dB down.  If it were used in a small 2-way,  it could produce substantial output at 96 Hz.  The HT4 design doesn't call on it to produce much of anything there. 

In retrospect, I wish I had thought of the Accuton in the first place.  I had a pair lying around from a previous experiment that didn't work out due to a tweeter with no low end output, and I forgot all about them.  When the FAL driver proved unworkable because of a design defect the factory couldn't fix, the light bulb finally clicked on. 

[Marbles]

Is it time to drop the HT4 designation? 

or 

Is it time to make it part of the name?



The design looks killer, wish I had the $$$$ to get a pair.

[Kris]

Going from a great 3 way (HT3) to a better 3 way (HT4) is not as dramatic as going to a Line Array or a WMTMW, or even a full OB. In my large room (18x22') i only have 2 and 3 ways, i really want to hear all 4 design types side by side in a big room to make sure what i get next is an upgrade.

[kenreau]

Thanks for the excellent explanations, Mr Murphy.

So, my notion is that explains why some of the larger MTM 3-way speakers use an active/built-in subwoofer amp.  It must help jack up the overall assembly sensitivity to align more closely with the MTM array.

Thanks
Ken

"1. The decision to use a MT driver design vs. a MTM three driver design.  Is it simply to balance speaker size & cost over diminishing performance benefits (in my limited understanding) of the MTM?  At this sota design level, I see numerous examples of each and wonder why I see no apparent consensus.  I'm thinking of the Song Towers, top models of Wilsons, Hansen, Eggleston, YG Acoustics, Magico, Evolution Acoustics (MTMs) vs. (TM) Usher BE, smaller Wilsons, Magico, YG Acoustics, Kharma, etc."

This really wasn't a close call.  One of the main advantages of an MTM configuration is added sensitivity overall and power handling in the bass.  But that only holds for a 2-way.   In a 3-way with one large woofer capable of plumbing the depths down to 19 Hz, the woofer sensitivity will establish the system sensitivity, and it will be quite low if the woofer can really deliver the bass goods (remember the Iron Law of bass).  So the added midrange senstitivity of an MTM would be completely wasted.  You would have to pad down the mids anyhow.  And the Accuton doesn't have to produce any low bass, so power handling isn't an issue either. 

"2. Midrange driver size.  The Accuton ~3"+/-4" diameter midrange.  Wow, that seems like a small diameter.  I understand the desirable benefits of speed and dispersion with smaller driver sizes, but how is the gap between the midranges lower end of ~300 Hz down to the woofer get filled?  There is obviously some juggling of sizes (maybe a 5"-6" midranges) with frequency ranges taking place."

The Fs (natural bass resonance)of the Accuton is 96 Hz.  It's crossed to the woofer at 350 Hz, so there is no hole in the response to fill.  The Accuton and the Big Hog woof blend together perfectly using 2nd order acoustic slopes.  And by the time the Accuton hits its Fs, it's 24 dB down.  If it were used in a small 2-way,  it could produce substantial output at 96 Hz.  The HT4 design doesn't call on it to produce much of anything there. 

In retrospect, I wish I had thought of the Accuton in the first place.  I had a pair lying around from a previous experiment that didn't work out due to a tweeter with no low end output, and I forgot all about them.  When the FAL driver proved unworkable because of a design defect the factory couldn't fix, the light bulb finally clicked on.

[DMurphy]

An active bass module would certainly deal with the sensitivity issue, at the cost of some flexibility in the choice of amplifiers and ease of set up.

[jsalk]

Is it time to drop the HT4 designation? 

or 

Is it time to make it part of the name?

Marbles -

You are right.  Time to drop the HT4 code name as it is not in the Veracity line and is a totally different speaker.  I changed the name of this thread to reflect that.

Thanks,

- Jim

[oneinthepipe]

Jim:

What are the amplifier requirements for the SoundScape 10 and SoundScape 12? 

[DMurphy]

Jim:

What are the amplifier requirements for the SoundScape 10 and SoundScape 12?

Since Jim hasn't chimed in, I'll give you my experience.  The SS10 is slightly more sensitive than the HT3, so whatever works for them will work for the 10's.  The 12's are a couple of dB more sensitive, so they would actually need less power.  Both models have almost identical impedance profiles--generally 4 ohms, never below, and somewhat higher in the midrange.

[Nuance]

So something in the 200-250 wpc for solid state should suffice, Dennis?  Obviously the more the better...

[DMurphy]

So something in the 200-250 wpc for solid state should suffice, Dennis?  Obviously the more the better...

I'm using Frank's 120 (?) watter on both, and I haven't had any problems knocking pictrures off the wall.  That's why you buy these things, right?

[oneinthepipe]

I'm using Frank's 120 (?) watter on both, and I haven't had any problems knocking pictrures off the wall.  That's why you buy these things, right?

Dennis, who's wall?  Your wall or your neighbor's wall. 

I wonder how the SoundScape would operate in a 205 square foot room      

Jim, what is the pricing?

[Big Red Machine]

Not if he paints them bright red like the pair of HT2-TL's he brought to RMAF. 

Why 'dis the red?  RED is good.

[WGH]

I loved the red too Big Red. I believe they were painted red so Jim could keep them, at past RMAF's someone always bought the display speakers. His strategy seemed to work because Dennis mentioned them in another thread.

...Jim had a pair of red (very red) HT2 TL's sitting in the corner that I would have loved to have heard alongside the HT4's, but I had to dash back to the airport.

Wayne

[Nuance]

I'm using Frank's 120 (?) watter on both, and I haven't had any problems knocking pictrures off the wall.  That's why you buy these things, right?

Absolutely! 

[titaniumhead]

Well, hopefully you didn't think Jim would try to sell a $10k  speaker that wasn't better than the HT3.  That's kind of what this exercise has been all about.  As for size, the 10" version doesn't look any bigger than the HT3 from the front.   The difference is in the depth--the bass portion of the HT4 is about 7 inches deeper than the HT3.  I don't know the specifics on  weight, but I doubt that the bass portion weighs more than the entire HT3.  And the midrange-tweet module isn't all that heavy.  So I really think the decision between the HT3 and the 10" version of the HT4 is basically one of price, not room size--unless your only alternative is to slam the speaker flat up agains the rear wall.  And that's probably not great for either speaker, though it would be particularly unfortunate for the HT4 since you would lose some of its soundstaging depth

Well that is my problem. I have no choice but to slam them up against a rear wall. Depending on the depth of the SS10 the most I will have is 28" from the back wall to the front of the speaker. At least I will have 4 feet from the sides of the speakers to the walls.And please dont suggest another speaker might work better in my situation. I have been saving my money ever since I heard them at the lincoln city audiofest and now can purchase them and I will not be denied.

[DMurphy]

"Well that is my problem. I have no choice but to slam them up against a rear wall. Depending on the depth of the SS10 the most I will have is 28" from the back wall to the front of the speaker. At least I will have 4 feet from the sides of the speakers to the walls.And please dont suggest another speaker might work better in my situation. I have been saving my money ever since I heard them at the lincoln city audiofest and now can purchase them and I will not be denied."

I better not deny you unless I want Jim to put a hit out on me.  No one in Washington would notice if there were one less economist walking around.  The rear opening of the midrange
cabinet is considerably short of the rear of the bass module.  So you would get some added information and soundstaging depth even if the bottom cabinet were close to the wall.  But it would be better if you bought a new house.