Paging JKrutke- ZD5- Now's that what I call a 2-way XO!

[tktran]

Hi John,

You've really outdone yourself this time.

Holy guacamole! I like it!

(Cringing of having to buy US$250 worth of crossover parts, but laughing at the prospect of how I'll fit this crossover into the cabinet :rofl:

[Jonasz]

The ZD5 will be my next project after finishing the NatP for my sister. :P

:T

[jkrutke]

(Cringing of having to buy US$250 worth of crossover parts, but laughing at the prospect of how I'll fit this crossover into the cabinet :rofl:

Oh yeah, I forgot to mention that all coils need to be 12 ga Goertz foil and all inductors need to be Mundorf Supreme. For C10, you might have to buy several and parallel them. Ok, now how much does it cost? Just kidding of course. :alol:

I forgot to mention that a couple of electrolytics in there for the big caps will be fine. I haven't really looked at the cost of the crossover, probably because I don't want to know. I had to seriously raid my bin of crossover parts just to hear the prototype.

[Martyn]

Zaph ZD5

John, there are several XT25 variants. The two most likely would seem to be the SC3004 and the TG3004. Which are you using? (and does it matter?)

[jkrutke]

John, there are several XT25 variants. The two most likely would seem to be the SC3004 and the TG3004. Which are you using? (and does it matter?)

Good point, yes it does matter seriously. It's the TG-30-04. Fixing up the page now. I'm sure over the next few days this page will get fleshed out a bit. I usually forget to detail a few things. Already fixed about 30 spelling and grammar errors.

[fjhuerta]

John,

I often hear designers say "I always tilt the response curve down." To that I say "I shape the response curve as required based on a balance of the audibility of distortion artifacts, the power response and the on axis response." Take note that always adhering to a certain on-axis response shape will result in a system design that sometimes works well. There is much more to it than what you see in an on-axis response curve.

I can't thank you enough for the time you take in posting your designs. I have learned a lot from them. In particular, that paragraph helped me a lot right now!

[Steve1655]

What is your reference speaker?

Thank you so much for sharing this and all your other designs with us.

Would you please tell us and post on your website what is your current reference speaker system? It looks like your main speakers are your 2.5 waveguide TMM speakers with the Seas CA18RNX and 27TDFC drivers. It would be helpful to understand if you prefer these over your Seas L18 / 27TBFCG speakers, and why. Then we could better understand your evaluation of your new ZD5 speakers.
Thanks, Steve1655

[John W]

Hi John,

Great project, spent several hours going over it last night and working on cabinet design which raised a couple of questions. Why did you decide in such a deep cabinet especially with the 25litre ported design when comsiderable volume is filled or used for the XO? Is the bracing adequate with so much area on the side walls supported by cross braces?

I am considering using your design and retaining the baffel and XO but modifying the cabinet by reducing its depth using a doubled-up baffel, a full length vertical brace and using the full volume of the cabinet, resulting in a higher WAF. Some lead sheeting would be used in the base to aid stability and the XOs would be external. External dimensions, excluding the base, would be 7" x 10" x 40"

I already have both drivers and most of the XO parts. I will have the wood cut this week if I'm not compromising your design.

I thank you for posting this project.

John

[ThomasW]

Some lead sheeting would be used in the base to aid stability and the XOs would be external.

Toxic speakers ......... :roll:

[John W]

Lead

Hi Thomas,

Umm... yes well err... perhaps not my brightest idea - another form of mass loading the base will be used instead, perhaps stone or a steel plate.

Strangely I was reading (on another forum???) of a manufacturer who lead-lined their speakers, but the obvious impact of using lead to mass load the cabinet passed without comment.

Thanks for pointing out what should have been obvious.

John

[jonathanb3478]

I read the paragraph on crossover components a couple days ago, and following all his recommendations (the serious ones, that is ), I came up with a crossover BOM of <$120 for the pair of them. Me likey! :T

Well, I did source all the caps and the 14ga air core inductor between Madisound and PE, depending on who was cheaper for the same thing:

Unit Value DCR Source Model # Qty Each Total
R0 (a) 5ohm n/a Madisound Eagle 2 $1.20 $2.40
R0 (b) 7ohm n/a Madisound Eagle 2 $1.20 $2.40
R3 2.5ohm n/a Madisound Eagle 2 $1.20 $2.40
R12 4.7ohm n/a Madisound Eagle 2 $1.20 $2.40
R19 6ohm n/a Madisound Eagle 2 $1.20 $2.40
R22 4ohm n/a Madisound Eagle 2 $1.20 $2.40
L2 .25mH 0.2 Madisound 19AWG 2 $2.75 $5.50
L4 0.5mH 0.35 Madisound 19AWG 2 $3.35 $6.70
L8 0.5mH 0.35 Madisound 19AWG 2 $3.35 $6.70
L11 1mH 0.5 Madisound 19AWG 2 $4.70 $9.40
L14 1.8mH <0.3 PE 266-365 2 $17.63 $35.26
L18 0.15mH 0.1 Madisound 19AWG 2 $2.50 $5.00
L21 0.3mH 0.3 Madisound 19AWG 2 $2.95 $5.90
C1-1 3.3uF n/a Madisound Bennic 2 $1.60 $3.20
C1-2 1uF n/a Madisound Bennic 2 $0.65 $1.30
C6 12uF n/a PE 027-430 2 $3.55 $7.10
C7 12uF n/a PE 027-430 2 $3.55 $7.10
C10 100uF n/a PE 027-360 2 $1.85 $3.70
C17 4.7uF n/a PE 027-422 2 $1.89 $3.78
C20 80uF n/a PE 027-358 2 $1.80 $3.60
$118.64

[jkrutke]

Would you please tell us and post on your website what is your current reference speaker system?

Well, reference implies a speaker that I keep around as a base of comparison. At this point for me that would be the Waveguide TMM. I really like the sound of it, and I see myself keeping it around for a while. I don't have a pair of L18/27TBFCG's in the house at the moment, otherwise I'd consider that the base of comparison.

I read the paragraph on crossover components a couple days ago, and following all his recommendations (the serious ones, that is ), I came up with a crossover BOM of <$120 for the pair of them. Me likey! :T

Thanks for throwing together that list. A couple notes: R12 should probably be a 4.0 ohm, considering the resistance of L11. That's what the green note means on the schematic. The other thing is that for L14 Madisound will custom wind an inductor for the cost of 20% above the next largest size. That means a Sledgehammer Steel Laminate 15AWG 1.80 will cost $12.36 based on the price of a 2.0 +20%.

On the other hand, the ERSE SUPER Q 1.8mH 16 GA at PE are nice with a DCR of 1.4 and only $13, but most people like to get all their crossover parts at the same place. PE's Part # is 266-902.

I think the Sledgehammer Steel Laminate is the best low DCR option. Power handling is high enough that saturation would never be an issue for this system, and the DCR is a nice low .15 ohms. I use those almost exclusively when I need low DCR, and I like the holes in the end of the steel cores for screwing them into a cabinet or mounting board.

[tktran]

Hi John,

I just thought I would give some feedback on this great crossover design.

I like the acoustic LR2 design, with great symmetrical vertical off axis response.

I couldn't find any mention of wall deadening and damping materials, in either the vented or sealed box versions. Is there any?

[jkrutke]

Hi John,

I just thought I would give some feedback on this great crossover design.

I like the acoustic LR2 design, with great symmetrical vertical off axis response.

I couldn't find any mention of wall deadening and damping materials, in either the vented or sealed box versions. Is there any?

With this project, I don't go into too much detail about damping materials, cabinet construction or any of the more common building issues. This project is meant for people with some speaker building experience. It goes without saying that some absorbtive material is required, but I leave that up to the builder.

The only thing I do note is that more absorbtive material is required at the ends of the longer dimensions to help keep the response smooth at the wavelengths related to the longest internet dimensions.

Actually, most of the stuff I'd normally recommend for insulation isn't available down under, such as Whispermat or Sonic Barrier from PE. It's hard to say if something not designed with acoustic properties in mind will be sufficient in it's absorbtion. If the it's not sufficient, it's easy enough to see in the impedance curve though, showing up as little bumps at related frequencies.

Also, for those who asked, I thought I'd mention the front to rear dimension is not important and can be modified to suit requirements, provided the internal volume is the same. The width should stay close to 7" though.

[Dave Littel]

ZD5 Damping

Hi John,

I just thought I would give some feedback on this great crossover design.

I like the acoustic LR2 design, with great symmetrical vertical off axis response.

I couldn't find any mention of wall deadening and damping materials, in either the vented or sealed box versions. Is there any?

For what it's worth, the sealed box John worked with while designing the crossover was damped with a combination of acoustastuf and semi-rigid fiberglass (SRF). SRF comes in panels of different densities. The one best for most speaker application is 3lbs. per Ft3. You can get 4' by 8' panels at any commercial insulation supplier for $7-8 per panel. What's the advantage? It stays pefectly in form and allows you to damp the box panels easily. It cuts very easily with a serated knife and you just snug the panels into place against the sides, top, etc. In this case I also placed some loose acoustastuff in the middle of the box. This combination has worked for me before in a situation where I did some detailed listening comparisons of different stuffing methods.

I'm currently putting together two new test boxes for the ported version and a transmission line. The boxes will be done this weekend but It'll be after that before I start any listening. (Yeah, getting the crossovers done has something to do with that.) I'll post here on my progress.

[Dave Littel]

P.S. The SRF panels are 1" thick. For this box I trimmed the side SRF panels to 1/2" thick because the box is so narrow.

[dCraig]

... Actually, most of the stuff I'd normally recommend for insulation isn't available down under, such as Whispermat or Sonic Barrier from PE...

jKrutke, you live in Australia? I will be in Sydney starting November 14th. If so, I would love to see your stuff if you are close by.

[ThomasW]

jKrutke, you live in Australia? I will be in Sydney starting November 14th. If so, I would love to see your stuff if you are close by.

Might be easier to touch base with him in Wisconsin... :T

[dCraig]

Oops! The "down under" reference threw me. Time for a shot of granola! ugh!. ops:

[jkrutke]

P.S. The SRF panels are 1" thick. For this box I trimmed the side SRF panels to 1/2" thick because the box is so narrow.

Dave,

How "nasty" is that stuff to work with? Gloves and respirator required? It seemed to work very well in the prototype.

Oops! The "down under" reference threw me. Time for a shot of granola! ugh!. ops:

I was responding to Tktran, who lives down under. :B Just fixed my location in my settings.

[Dave Littel]

The SRF is no nastier than fiberglass batting. I did have some itching going on last weekend after I worked with it.

Tonight I routed out the driver cutouts in the padauk baffles. That stuff (the wood) is drop dead gorgeous. These baffles are 40" long and will be used for both test boxes. We're getting there.

[marsel]

Hey any one(especially you Jkrutke ;x( ) can tell me where J can find some info of

a ladder delay network.

I could find only some general papers on this topic but nothin really precise.
I want to get into this topic :roll:

It is really a hi-end project especially concernig the solutions.

[jkrutke]

Hey any one(especially you Jkrutke ;x( ) can tell me where J can find some info of a ladder delay network.

I could find only some general papers on this topic but nothin really precise.
I want to get into this topic :roll:

It is really a hi-end project especially concernig the solutions.

I made a minor website update that goes into it in a little more detail.

[dlr]

You do have SoundEasy, don't you?

I had to seriously raid my bin of crossover parts just to hear the prototype.

You really need to use the Digital Filter in SoundEasy. It's fantastic for auditioning. Forget constructing prototypes. I go through literally a dozen or so versions of various orders/Fc/topologies playing with any system.

Get a decent 6-channel amp and you're in business. There are quite a few varieties on ebay. The Kenwood KM-X1 is a sleeper IMO. 100W/ch., all 6 channels are full-range and it's built solidly. In 2-channel mode it's got 130W/ch.

[jdybnis]

Trusting that the low-end performance of the scanspeak is excellent. Do you notice any coloration from the paper cone?

[jkrutke]

You really need to use the Digital Filter in SoundEasy.

Yup, I've used it a few times and I should probably use it more. I'm more limited by my current sound card, which only seems to do 2 channels at a time, limiting me to a single 2-way channel. Otherwise I love the card, since it's very low noise and flat right out to 44khz. I do keep a "noah's ark" of crossover components though (2 of everything) and a huge pile of alligator clips, so most of the time it's easy enough to just lay stuff out on the floor and get it working.

Trusting that the low-end performance of the scanspeak is excellent. Do you notice any coloration from the paper cone?

The Scan Speak has very little sound of it's own. There's a bunch of people out there who think they know what "paper sound" is, probably the same crowd who thinks they know what "metal sound" is. Drivers do have their particular character, but it's simply based on the distortion profile. All paper and all metal cones should not be lumped into the same categories as there are vast differences among them.

[xmax]

paper sound?

well, I think slits in the cone make them very different sounding
then other paper cones, but John has a point, there are many
diffent paper cone speakers out there and some have huge
stiff dust caps, some big metal phase plugs. all very diffent.
but the non-coated version are a little more papery?

Oh, and thanks John your work on this ZD5 has helped me
with a 8545k/XT-25 project I just finished (I know not the
best combo, but had to clear some room in the driver locker)
also I added a neat trick, I added some extra posts on the
back of the box that are hooked right to the leads on the
pad resistor, I put a 8ohm, but the posts allow me to
lower the resistance to taste or stick a small cap
on there to add some "air". COOL SITE, Norm

[TacoD]

Sliced cones from Scan Speak are easy the recognize. I think it is wise to hear those units first, before you buy them.

[ThomasW]

:agree:......I think they tend to 'homogenize' the sound.

[tktran]

<sigh>

And I use to think that only the hifi rags were culprits of waxing lyrical.

"more papery"
"homogenize"
"engineered"
"snap"
"intimate presentation"

What the?

[augerpro]

:agree:......I think they tend to 'homogenize' the sound.

expound please...

[TacoD]

The sliced cone, has a strong mid bass, male voices have a lot of chest. Besides this feature there is nothing special. When you correct for the hump in the FR, the sound is not that spectacular anymore. It has simply not the resolution, snap of other types of cones.

I have to admit that you can make a very nice sounding loudspeaker (done that myself), but the sound is far from being neutral. The stage is compact and you'll get a intimate presentation. It's like the Scanspeak 7000 tweeter, it sounds very nice but you can hear that the sound is "engineered", like almost every Scanspeak unit.

[jkrutke]

The sliced cone, has a strong mid bass, male voices have a lot of chest. Besides this feature there is nothing special. When you correct for the hump in the FR, the sound is not that spectacular anymore. It has simply not the resolution, snap of other types of cones.

I have to admit that you can make a very nice sounding loudspeaker (done that myself), but the sound is far from being neutral. The stage is compact and you'll get a intimate presentation. It's like the Scanspeak 7000 tweeter, it sounds very nice but you can hear that the sound is "engineered", like almost every Scanspeak unit.

When the discussion starts to get too subjective, I like to wear these:



:rofl: :B

[TacoD]

You're right I am subjective, and I tried answering a question of augerpro. My reaction was about the sound of the sliced cone, I did not say that the ZD5 is a bad sounding loudspeaker. My excuses if I offended you.

I used many Scanspeak drivers in the past (8543, 8544, 8546, 8535, 8550, 8530, 8531, 9800, 9900, 6600, 7000, 2010) in several designs and also using some drivers more than once in different configurations. So I wanted to share my experiences with some drivers, I thought that is what a forum is all about.

[subjective mode on]
Sometimes measurements are not conclusive and drivers with comparable FR can sound differently. Also if you're new to this hobby it's hard to relate distortion plots to sound. And even a lot of pro's can only show a distortion plot without correlating this to sound perception.
[subjective mode off]

[SoundEngine355]

I read the paragraph on crossover components a couple days ago, and following all his recommendations (the serious ones, that is ), I came up with a crossover BOM of <$120 for the pair of them. Me likey! :T

Well, I did source all the caps and the 14ga air core inductor between Madisound and PE, depending on who was cheaper for the same thing:

Unit Value DCR Source Model # Qty Each Total
R0 (a) 5ohm n/a Madisound Eagle 2 $1.20 $2.40
R0 (b) 7ohm n/a Madisound Eagle 2 $1.20 $2.40
R3 2.5ohm n/a Madisound Eagle 2 $1.20 $2.40
R12 4.7ohm n/a Madisound Eagle 2 $1.20 $2.40
R19 6ohm n/a Madisound Eagle 2 $1.20 $2.40
R22 4ohm n/a Madisound Eagle 2 $1.20 $2.40
L2 .25mH 0.2 Madisound 19AWG 2 $2.75 $5.50
L4 0.5mH 0.35 Madisound 19AWG 2 $3.35 $6.70
L8 0.5mH 0.35 Madisound 19AWG 2 $3.35 $6.70
L11 1mH 0.5 Madisound 19AWG 2 $4.70 $9.40
L14 1.8mH <0.3 PE 266-365 2 $17.63 $35.26
L18 0.15mH 0.1 Madisound 19AWG 2 $2.50 $5.00
L21 0.3mH 0.3 Madisound 19AWG 2 $2.95 $5.90
C1-1 3.3uF n/a Madisound Bennic 2 $1.60 $3.20
C1-2 1uF n/a Madisound Bennic 2 $0.65 $1.30
C6 12uF n/a PE 027-430 2 $3.55 $7.10
C7 12uF n/a PE 027-430 2 $3.55 $7.10
C10 100uF n/a PE 027-360 2 $1.85 $3.70
C17 4.7uF n/a PE 027-422 2 $1.89 $3.78
C20 80uF n/a PE 027-358 2 $1.80 $3.60
$118.64

I have some Jantzen Audio Air Cored Coils which are 18AWG and 20AWG, which would be best to use for the L2,4,8,11,14,18,21?