ZDT3.5 or Mini statement

[pierre666]

Hi you all,

I am still juggling with my next project choice. I have 2 candidates; Zaph's ZDT3.5 and Curt's Mini statement.

I know the the mini statement might be more expensive to build but I do not want to put that into consideration. If it is worth it, this speaker will stay a while in my living room so...

Is the TB W4 a better performer then the RS52 ?

I guest that the Fountek tweeter is a more Hi-end driver then the ND20 (by the price) but what about the sound ? What is the sound of a ribbon like ?

For those who have already built Statement or projects using these drivers, what king of sound do you like ? ( i guest what kind of music do you listen to ?)

And anyone has built the ZDT 3.5 around ?


Thanks for your comments,

Regards

Pierre

[JonMarsh]

That's a pretty open ended question. There are pro's and cons all around. I can address or comment on a few topics or issues, based on my own experience designing and building and living with a speaker somewhat similar to the ZDT 3.5, but ultimately it comes down to what's important for you.

For reference, my own design is described in this thread:

Modula NeoD CC Center/Mains


This design was started mainly as a compact center channel, but without modification has been pressed into service as a "mains" speaker with very pleasing results. Small size was a prime consideration, which is part of why the RS52 midrange driver was selected, as it doesn't require a sub enclosure, and the whole design could be done in a 1 cu ft pre-made enclosure, for ease of construction for other builders. Driver selection was focussed on low midrange distortion and excellent CSD behavior; the RS52 is quite low in distortion and consistent across a wide range of frequencies, and has good CSD behavior in the critical range from 1 kHz to 10 kHz. A Deulund style crossover was planned, so a wide usable response was necessary for the midrange, as well as a clean well behaved midwoofer with T/S parameters suited to a smallish box. The W4-1337 as used in the Statements is one of the few cone mids that would have been clean enough for this in the top end, but it still required a sub enclosure, of course. The tweeter I selected was the Vifa D26NC55; it's CSD and distortion behavior are pretty much unmatched by any other small form factor tweeter, and few larger more expensive tweeters, and in practice with the RS52 and a good crossover (the Duelund), they both pull a disappearing act thats hard to match (hear the recording, not the speaker).

With the Duelund style crossover, and the driver clustering implemented, this system has very wide dispersion in every direction, which is why it works well as both a center channel laid down, and as a "mains" type speaker standing up on stands. Unlike most conventional designs, which have fairly good sized crossover nulls in the mid-tweeter crossover range as you move vertically, this system has very uniform power response vertically (they work great in my family room even when I'm standing on my Nordic Track Elliptic trainer and my head is up at around 8 ft off the floor), and with the mid drivers towards the inside, the dispersion and uniformity is wide for stereo listening, too.

There are two things to keep in mind with regard to the Statement style systems. First, they do use rear radiation through the midrange tunnel, somewhat filtered acoustically, and this is factored into the crossover, and has some bearing on how they sound with regards to rear wall placement- follow Jim's and Curt's recommendations. 2nd, the Fountek is a good moderate cost ribbon tweeter, skillfully used in this design; the weakness of ribbons tends to be in how low they can go, and the W4-1337 helps with this, as it goes higher than most cone midrange driver; the statement systems use a 5 kHz crossover point. This high a crossover point mandates that the drivers must have as small a C-C distance as possible; in this regard, the smaller Statement monitor probably does a better job than the stacked MTM version, unless you value the more restricted vertical dispersion. Also, the height of a ribbon tweeter will tend to limit the vertical dispersion window, so the power response will tend to be wide above 5 kHz, as for a 3/4" tweeter, but somewhat narrower than typical vertically. The only way I know to remedy that is either by variable density acoustical foam to limit the height of the area radiating in the higher frequencies (as RAAL does), or by using a line array of drivers (that's why I've got boxes with 16 4" Fountek tweeters in storage... :W

One of my friends likes to listen to music or watch TV/movies lying down on the floor (good for his back), so this kind of system wouldn't be for him.

Ribbons tend to be free of upper end resonances that can cause distortion amplification in more conventional drivers, but as in all things, no generality is worth a dang, including this one- that Vifa D26NC55 has very low high order distortion, very low distortion in general, and no upper end resonance from it's soft dome design. (it does beat out the ND20 in pretty much all regards, but then you get what you pay for- OTOH, availability has been intermittent- currently in stock again at Madisound). So, I'd just say a lot depends on the specific driver execution AND the complete crossover and system design. There's a lot of very satisfied owners of the Statement systems in their various incarnations and sizes, and clear they offer very good value relative to the expense and construction difficulty.

Since I've heard neither the ZDT 3.5 or the Statements, at this point, I think I'm done commenting! Either could probably be adapted with good results to your proposed TL configuration; both having the same LF drivers will have the same considerations regarding line size and damping. In your shoes, I'd prototype some LF cabinets and make sure that's sorted out before doing the "official build" cabinets.

[Jim Holtz]

Just one minor correction to John's excellent summary. The Statements series speakers are crossed from the W4-1337 to the ribbon between 3750 Hz. and 4000 Hz. depending on the design. That does allow for CTC spacing within one wave length due to a ribbons unique advantage of emitting sound from the full length rather than only the center. Anyway, that helps vertical dispersion greatly.

I'll let others comment on sound quality etc. I think I'd probably be a bit biased.

HTH

Jim

[JonMarsh]

The equivalent to the ZDT 3.5 which Pierre could be using in a TMWW TL is the Statement Mini or Center, for which Curt's published LspCAD data is as follows:




Dat shore do look like a 5 kHz crossover to me! Here the C-C distance of interest is the W4-1337 to Fountek.

In the case of the bigger statements, the critical distance is the C-C distance between the two W4, with the tweeter in between;



as can be seen, the crossover point has been lowered to 3.5 kHz, and the slope increased on the tweeter a teensy bit.

The wavelength at 3.5 kHz is about 3.9", so the source height (C-C is 9-3/4") at the crossover frequency will be a bit high for the statements, but will probably give vertical dispersion in the crossover region similar to what the tweeter does higher up on it's own.

[pierre666]

Efficiency....

According to the graph, afficiency shouldn't be very high...

Tell me why we are never able to get good efficiency (+90db)?!!!!!!

Since the woofers are in parallele, shouldn't they be more efficient?

Pierre

[pierre666]

Just one minor correction to John's excellent summary. The Statements series speakers are crossed from the W4-1337 to the ribbon between 3750 Hz. and 4000 Hz. depending on the design. That does allow for CTC spacing within one wave length due to a ribbons unique advantage of emitting sound from the full length rather than only the center. Anyway, that helps vertical dispersion greatly.

I'll let others comment on sound quality etc. I think I'd probably be a bit biased.

HTH

Jim

I was looking at the cad drawing...no mention of damping (alsp pad or carpet underlay or acousta foam)? Is there any?

Pierre

[JonMarsh]

Pierre, the RS180 is about 87 dB/2.8s VRMS to begin with- but that's IB response- 180 inlcuded angle. In a free standing cabinet, you must provide baffle step transition compensation, because in the upper midrange and above, the driver radiates into a 180 degree angle; below some lower point determined by baffle size, (typically 150-250 Hz) it's 360 degrees, and 6 dB lower.

So, paralleling two RS180 results in IB sensitivity of 93 db, but after applying 4-5 dB of BSC (few designs use a full 6 dB), you wind up with a net voltage sensitivity of 88 dB/2.83V, and that is before considering inductor resistance losses- for a three way with a lower crossover point this can be a dB or so.

Last, consider the reality of physics and Hoffman's iron law- there is an inviolate relationship between efficiency and enclosure volume and LF cutoff- drivers with high efficiency require much larger enclosures to get the same LF cut-off - go model the RS270 Dayton if you'd like to see a good example. Yes, you can build a high efficiency system with extended bass using two of the Dayton RS270 10's in parallel, but it winds up being rather large, compared to the size needed for say, a Seas L26ROY or an Aurasound NS10-513, which even with 4 ohm load impedance instead of 8 give up 2 dB or more voltage sensitivity. RS180's are a sensible design balancing sensitivity and LF extension and enclosure size. My usual recommendation for two of them is a 40-50 liter enclosure tuned to 30-32 Hz with a 3" ID port, and not with the drivers off to one end, but located about 1/3 to 2/5 from one end.

[cjd]

Yes, you can build a high efficiency system with extended bass using two of the Dayton RS270 10's in parallel, but it winds up being rather large

Pshhh. that's not large. (so you don't have to dig it up, 14x24x50 with 1.5" baffle and 1" walls, minus mid enclosure) They sure sound good though. Not that those other drivers don't similarly sound good.

[Jim Holtz]

Hi Jon,

Curt explained this to me a long time ago. So, I'm going to let Curt respond to your remarks about crossover points, spacing etc. I can tell you the full sized Statements have excellent vertical dispersion and almost give a "walk around" type image. No head in the vice listening positions. :T

Jim

[Jim Holtz]

I was looking at the cad drawing...no mention of damping (alsp pad or carpet underlay or acousta foam)? Is there any?

Pierre

Hi Pierre,

Sorry, you'll have to read the thread or go to Curt's website for more detailed info. The short of it is, I used 2" wedge foam in the woofer compartments and 1" flat foam in the mid tunnels. There are specific recommendations on the mid tunnels.

Jim

[savage25xtreme]

Hi Jon,

Curt explained this to me a long time ago. So, I'm going to let Curt respond to your remarks about crossover points, spacing etc. I can tell you the full sized Statements have excellent vertical dispersion and almost give a "walk around" type image. No head in the vice listening positions. :T

Jim

I would agree with Jim here, not sure how they did it with a ribbon, but I sat on Jim's couch and walked all around that room and unless you put your head about 6 inches from a side wall I really couldn't hear a difference...not to say that the dispersion couldn't be measured and see the difference in on and off axis and vertical, but I couldn't hear it. on the other hand I didn't listen to many tracks that I can remember with a lot of symbols to work out the ribbons. I am just chasing my tail here :roll: , but you get the idea, I listen to the Statements for 2 hours and watched some of Iron Man. Very good sound stage and imagining, but then again I am just a padawan, and not well versed in the ways of the force. To date, the Statements are the best I have heard....I have not heard the mini-statements.

[Brian Walter]

Pierre, I have listened to both the mini statements and the ZDT3.5, although it was about a year between the listening sessions so my recollection might be a little off. I heard the ZDT3.5 (both tweeter versions) last fall and I must admit I was a little disappointed, maybe I was expecting too much. I'm not the only one who had that impression either as they didn't finish all that high in their class. On the other hand, I was very impressed with the mini-statements when I listened to them a year earlier.

I have a need to build some new smaller speakers, similar to the ZDT3.5 and even though I have all the drivers to build the ZDT3.5 I'm doubt I'm going to build them. I will probably end up building either the mini-statements or the Selah Audio 35F. The 35F uses 2 - RS180', the Morel MDM55 dome mid and a Seas 3/4" dome tweeter and happens to match my center channel.

Brian

[pierre666]

I will probably end up building either the mini-statements or the Selah Audio 35F. The 35F uses 2 - RS180', the Morel MDM55 dome mid and a Seas 3/4" dome tweeter and happens to match my center channel.

Brian

Do you have all that it takes to build the 35F (cad et/or crossover schematics etc)?

Pierre

[Brian Walter]

Do you have all that it takes to build the 35F (cad et/or crossover schematics etc)?

Pierre

Hi Pierre, no I don't have all I need to build the 35F. This is a proprietary design so I would need to go through Selah Audio to buy the kit. I haven't checked with Rick, but I might be able to get a discount as I already have the RS 180's. Then again, I could try my own hand at designing the crossover, but that's probably more work than I have time for and I'm sure my results would be nowhere near as good as Rick's.

Brian

[pierre666]

Hi Pierre, no I don't have all I need to build the 35F. This is a proprietary design so I would need to go through Selah Audio to buy the kit. I haven't checked with Rick, but I might be able to get a discount as I already have the RS 180's. Then again, I could try my own hand at designing the crossover, but that's probably more work than I have time for and I'm sure my results would be nowhere near as good as Rick's.

Brian

Does Selah sells the plans? or you have to buy the kit ?

Pierre

[bemis23]

Pierre, I have listened to both the mini statements and the ZDT3.5, although it was about a year between the listening sessions so my recollection might be a little off. I heard the ZDT3.5 (both tweeter versions) last fall and I must admit I was a little disappointed, maybe I was expecting too much. I'm not the only one who had that impression either as they didn't finish all that high in their class. On the other hand, I was very impressed with the mini-statements when I listened to them a year earlier.

I have a need to build some new smaller speakers, similar to the ZDT3.5 and even though I have all the drivers to build the ZDT3.5 I'm doubt I'm going to build them. I will probably end up building either the mini-statements or the Selah Audio 35F. The 35F uses 2 - RS180', the Morel MDM55 dome mid and a Seas 3/4" dome tweeter and happens to match my center channel.

Brian

Can anyone else comment on this? i was looking to build a pair of ZDT3.5s soon, but if the Mini-statements are a better choice. I might need to hit the drawing board again.

[Jim Holtz]

Can anyone else comment on this? i was looking to build a pair of ZDT3.5s soon, but if the Mini-statements are a better choice. I might need to hit the drawing board again.

Here is a link to the 2007 Iowa DIY results. You decide.

Jim

[Jed]

Can anyone else comment on this? i was looking to build a pair of ZDT3.5s soon, but if the Mini-statements are a better choice. I might need to hit the drawing board again.

I'm sure they are both very good. My personal preference would be a design with the W4 1337. I used it in the Lineup Series and have had positive feedback on those designs. The little titanium cone sounds very good for the money, and they have performance to back it up. Then again someone could argue the same about the RS52. I've used both and the W4 implementations I've tried always please my ears.

That said, JonMarsh and John Krutke aren't exactly amateurs in crossover design, and I'm sure they can get the RS52 to sing.

[Curt C]

The equivalent to the ZDT 3.5 which Pierre could be using in a TMWW TL is the Statement Mini or Center, for which Curt's published LspCAD data is as follows: Dat shore do look like a 5 kHz crossover to me! Here the C-C distance of interest is the W4-1337 to Fountek.

John the reponse plot for the Mini Statements and Statement CC are significantly different as far as the tweeter fc. Here is the MiniStatements response plots, which cross much lower than the center:



Why is the CC ribbon crossed so high? 'Cause the darn thing wanted to be up there, and if it was going to be so stubborn about it, I wasn't going to force it into submission.:B

In the case of the bigger statements, the critical distance is the C-C distance between the two W4, with the tweeter in between;



as can be seen, the crossover point has been lowered to 3.5 kHz, and the slope increased on the tweeter a teensy bit.

The wavelength at 3.5 kHz is about 3.9", so the source height (C-C is 9-3/4") at the crossover frequency will be a bit high for the statements, but will probably give vertical dispersion in the crossover region similar to what the tweeter does higher up on it's own.

The crossover frequency of the Statement mid/ribbon was a careful compromise between the vertical polar response of the drivers and the distortion characteristics of the Fountek. The modeled vertical polar response around the crossover frequency has an acceptably sized lobe of +/- 10 to 15 degrees from the design axis before the lobe is down -3 dB. I didn't notice any audible aberrations with vertical variations in listening position during the voicing of the speaker.

C

[bemis23]

Here is a link to the 2007 Iowa DIY results. You decide.

Jim

*groan* 'Ya just can't get a straight answer around here ;P

Those are some great pics. I apparently have some soul searching to do now since i'm going to be budget limited to just one project for quite a while.

That said, i've added structured wiring to my house to allow for a 5.2 system to be wired in preparation for running a sealed zdt3.5 w/ the bamtm sub included below that (as in, each of the mains' outlets have a pair of binding posts).

I don't want to just leave those wires rotting in the wall and good for nothing, right? Maybe i'll consider adding some bassbins to the bottom of a pair of Ministatements?

Geez, I'm already back to the drawing board and i've not even made one scrap of sawdust yet. If anyone has any ideas send me some PM's, I've threadjacked too many people today already.

[DeathMonk]

Either one you build I think you will be happy.

I built the ZDT3.5s for my dad and I am going to build the big ole statements for myself (as soon as I get this bose buster 5.1 setup off my plate!)

[Blktre]

Here is a link to the 2007 Iowa DIY results. You decide.

Jim

Yup......less than 1 point from top to bottom. Also remember i was running a hotter tweeter that day on the 3.5. Since then, there has been more ZDT3.5 builds and everyone has agreed not to use the 2ohm resistor on the tweeter. With that said, i thought all the designs sounded great!

Whooops Jim....Im a year off. Im talking 2008 and the Mini Statements. Fwiw, i got to listen to Jims big ones on the way home. Nice indeed.

[Brian Walter]

Yup......less than 1 point from top to bottom. Also remember i was running a hotter tweeter that day on the 3.5. Since then, there has been more ZDT3.5 builds and everyone has agreed not to use the 2ohm resistor on the tweeter. With that said, i thought all the designs sounded great!

Whooops Jim....Im a year off. Im talking 2008 and the Mini Statements. Fwiw, i got to listen to Jims big ones on the way home. Nice indeed.

Actually, I think your are talking about the Statement Monitors, not the Mini-Statements. The Minni's use dual RS180's as opposed to a single RS180 in the Monitors. Both are excellent sounding speakers, but there is definitely more weight to the bass in the Minni's. If Jim wasn't so modest he'd tell you what he really thinks.

There's no doubt in my mind that Jon Marsh, John Krute and Curt are excellent crossover designers, any of which are capable of producing excellent designs. It may be that in balancing the trade offs between cost and performance John Krute may have sacrificed a little more performance for cost in the design of the ZDT3.5's than Curt did with the design of the Mini-Statements. This may be why the Mini-Statements sound better to me, but then again it may just be a person preference.
Brian

[Jim Holtz]

If Jim wasn't so modest he'd tell you what he really thinks.

Brian

Thanks for the kind words Brian but my wife would definitely disagree with you. :rofl:

Actually, I posted my thoughts in the beginning of each of the Statements designs main threads so I thought I'd let others like yourself offer your thoughts. You're less biased than I am.

Jim

[Blktre]

Brian, you are so correct. Thanks for the correction. Jim was nice enough to open his house up to us for a private listening session. After hearing all three designs, all i can say is what a package. Ive always heard ribbon tweets could sound harsh. But this is just not true as Curt and Jim proved so well with the Statement lineup.

Owning the ZDT3.5, i am very pleased with the accuracy, imaging, and sound stage of these speakers. Best Ive ever owned. But without spending some serious time with the Statements, Its hard for me to justify how far apart these speakers are against the ZDT3.5. All i know is you wont get hurt on either design. But the beauty of the Statement lineup is just that. You can pick and choose which one will fit your room and budget. And that right there is a huge benefit over the ZDT's.....

[agrippa]

Data mining turned this up.
3 questions:
1. What is the recommended distance from a wall for both of these designs?
2. Am I correct in that the ZDT3.5 has been improved since 2009? I have heard several people rave about them...as well as the mini statements.
3. Has anyone heard the ZA5 series at a event? How do they measure up?
Thanks

[Jim Holtz]

Data mining turned this up.
3 questions:
1. What is the recommended distance from a wall for both of these designs?
2. Am I correct in that the ZDT3.5 has been improved since 2009? I have heard several people rave about them...as well as the mini statements.
3. Has anyone heard the ZA5 series at a event? How do they measure up?
Thanks

18"from the back of the speaker to the wall behind for all versions of the Statements except the near wall version of the Monitors.

Jim

[oneplustwo]

Data mining turned this up.
3 questions:
1. What is the recommended distance from a wall for both of these designs?
2. Am I correct in that the ZDT3.5 has been improved since 2009? I have heard several people rave about them...as well as the mini statements.
3. Has anyone heard the ZA5 series at a event? How do they measure up?
Thanks

I love my ZDT3.5. I do not remember them being improved upon and don't think there's reference to that on the site. I built mine in 2010 I think. That said, I'm building the full statements next. More for fun and curiosity for the ribbon than anything else.