Zigmahornet follow up

Hi folks.

First, thanks to those who brought plans and needed infos for this project.

Initial thread was "Zigmahornets on their way".For those who haven't read the thread, first impressions went like this :bawling:

I used the Foster 10RG11. My living room is medium sized, but I got almost no bass at all, and quite a hot and peaky treble. Dragging the speakers close to the back walls brought a better balance, but still hot mids and treble, almost no bass. Same with 4.5" Philips, but with a more civilised and extended treble.

I got unexpected good results with a little 4" of unknown maker. Model YDD-103.

A little less treble extension and details, but great midrange clarity, good highs, and articulate bass, though not big bass. But what's there is decent.

Next, I want to try the Fosters again and try to live with them. Hey, Planet 10, could the phase plug trick bring some balance with them? Then, probably try the Bipole config.

Any suggestions? experiences to share??

Oh, I was forgetting. It's always a bit difficult to describe with words the emotions a speaker can cary or not.. My Zigs are not perfect, that's for sure, but though I still have strong reservations about them, there's lot of positive things I like about them. With the YDD drivers, they are lively, coherent, quite 3D and fun to listen to.

For now, all what is missing, is a wee bit of treble extension, not much, (could I add a phase plug?) an slightly more solid, or more believable lows.. but for that, I'd have to go for the Swan 101, and it seems to represent so much work, I'd need to have a listen to a pair first, before starting the project.

Not so bad for a starter project. What's next??

Could a 12" Tannoy HPD be put in a Zigmatower?? (this time I'm sure I'd get real kicking bass.. he he;) )
 

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Fosters 10RG11 VS Fostex 103?

I'd like to know if someone here did compare both of these drivers. I got a ragged peaky treble from the 10RG11. Is the Fostex 103 like this too?

And has someone tried the "phase plug" mod with it and compare the results?

Any suggestions welcomed.

And is stuffing a major factor in the treble/mid response of the drivers?
 
MJK said:
Sylver300B,

I did not follow the initial discussion. From your description of the sound, it would appear that a BSC filter would help your speakers become better balanced. The mids and highs would be tamed so that the bass was in proportion. Have you considered trying this type of filter?

No, I didn't think of it, but it rather makes sense.. The drivers I wished to use are the Fosters 10RG11. Is a BSC filter common use with these drivers??

Used "as is" it reminds me of my former Lowther academy. Not my type of sound. Detailed and fast, but hot and spicy, un-natural with lots of peaks and dips.

And how does one calculate such a filter? And isn't it any danger to loose the transparency of the original drivers?
 
YDD-103 driver

jemraid said:
Hi Sylvain,

I've been following the thread about this and was disappointed with you after you'd made such a good job of the boxes, they look great!

I found some info about the YDD-103's here;
http://www.linanwindow.com/speaker/big/ydd103-4.htm

It's the LINAN EURO-CHINA Co., Ltd. They make a whole range of drive units.

Regards - Jem

Thanks for your positive comments on my boxes! :D You're the first one to compliment me and yes, I worked quite hard on them. Remember, I'm a beginer. :cannotbe:

About the "unknown" drivers, thanks for the link. A friend of mine sent me this:
http://www.addison-electronique.com/catalog/advanced_search_result.php?keywords=ydd&x=0&y=0

You'll get the pic of the drivers.

May be the Fosters with a BSC filter could make the job in the Zigmas, but I must say that I've been surprised at how nice these YDD drivers sound good as is. All is missing is a slightly more extended treble, but what is there is quite promising, even the bass.
 
BSC filtering

sklimek said:
Hi, I love the look of the Zigmas and have watched your journey w/ them. Myself, I am new with the speaker part of diy but studying hard and would love to see your Ziggies make it for you. You've done a great job. Maybe this link can help you w/ the BSC, baffle step correction if you have not already spotted it.

Stan

Hi Stan,

Listening to Shirley Horn right now, and I must say it sounds quite good. Just lacking some sparks in the highs. So, there is hope.

As for the BSC filtering link, thanks for that. I'll try it with the Fosters.

I'm distracted by the Zigmas right now. As I write you, there is a trumpet in the intro and the bass comes in gently. Beautiful. I think the Zigmas deserve that I learn more about them, the BSC filters..

Sure, my ignorance is in the way, and it's not always evident where to look, and what to look for.. But right now, what I hear tells me it's not time to give up.

;)
 
Is a BSC filter common use with these drivers??

BSC filters are not commonly used with single driver systems. For years the purist philosophy has been to place nothing between the amp and the driver that might corrupt the sound. My experience has been that the uncorrupted sound can be so midrange dominant that quite frankly the speakers sound terrible. With very few exceptions, my opinion is that almost all single driver systems would benefit from some amount of baffle step correction. To much correction and you have the other problem of loud bass and muffled midrange. It takes some trial and error tweaking to get it right.


Used "as is" it reminds me of my former Lowther academy. Not my type of sound. Detailed and fast, but hot and spicy, un-natural with lots of peaks and dips.

Exactly, great description. Try a BSC filter with these also, I use one on my Lowthers and really like the results.


And how does one calculate such a filter?

A link was provided above to one sizing method that I wrote a while back, personally I like to design the filter using actual measurements. The sizing calculations should get you in the right ballpark.


And isn't it any danger to loose the transparency of the original drivers?

If done incorrectly, the performance will suffer. If done correctly I do not believe anything is lost. All the filter does is adjust the relative volume levels of the mid and high frequencies downward to match the bass. You do loose a few dB of efficiency, I don't believe this is a big issue even with low power tube amps. The filter is a frequency dependent volume adjustment, nothing more.

Hope that helps,
 
BSC filter

MJK said:


If done incorrectly, the performance will suffer. If done correctly I do not believe anything is lost. All the filter does is adjust the relative volume levels of the mid and high frequencies downward to match the bass.

You do loose a few dB of efficiency :dead:
I don't believe this is a big issue even with low power tube amps. The filter is a frequency dependent volume adjustment, nothing more.

Hope that helps,

Yes it helps.

After my first listening tests, I was so disapointed that I tried my Behringer Ultracurve to see what's going on and try some correction. There were peaks and dips around the treble area, and as well, a suck out in the mid bass, leading to the perception of lack of "foundation" for the tonal balance. The low piano keys would sound "hollow" and thin. Not like a real piano. And the voice (Diana Krall for example) seemed like shouting at you with lots of sibilance.

My source is my ol' pal Meridian 506, and my tube amp is my homebuilt 300B SE, wich I use for the last 8 years, and that I know it is transparent and silky in the highs.

Using the Behringer sure was quite a bit like putting a BLC in the path. (no?)

Would adding a second driver at the pack (bipole) be another solution?

I might try that as well.

Last question: and what makes the YDD-103 driver sound so different of the 10RG11? Then the BSC calculation should be different from one driver model to another?
 
Would adding a second driver at the pack (bipole) be another solution?

That is a potential solution for baffle step but it needs to be designed into the speaker before it is built. A second driver will require the enclosure volume to be doubled, the cross-sectional area needs to be doubled. So adding a second driver later is probably not a feasible for an already finished project.
 
BSC

MJK said:


That is a potential solution for baffle step but it needs to be designed into the speaker before it is built. A second driver will require the enclosure volume to be doubled, the cross-sectional area needs to be doubled. So adding a second driver later is probably not a feasible for an already finished project.


Well, I agree with you, but as well, I took the initiative to make a second opening for a second driver at the back, and I have extra pairs of drivers... so, why wouldn't I give it a try and see?
 
The phase plugs on the FE103A extend the top end, give better HF dispersion, and are the final nail in the coffin of a midrange coloration most noticable in male vocals (ie the phase plug playing one of its major roles of filling th ehole after the dustcap is removed.

For myself i don't do it without the other tweaks 1st, they all fit together to make this driver much better than stock.

Martin makes a very good point about BSC. The Zs are going to have a BS depression below about 960 Hz, which makes everything above that too prominant. All the speakers we have used and built with the FE103A have been bipoles or horns where, with the highish Q, the bass is naturally lifted, so a BSC filter was not required. So well worth trying in your application.

As for the bass, just looking at the dimensions of the Z, it is designed for a driver with an Fs on the order of 65 Hz. The FE103s i have measured run between 80 & 130 Hz, with 90 to 105 predominating. Here for instance is a pr of 10RG11s with a particularily low Fs. With tweaks one might get these in the range of that optimal for a stock Z.

Here a bit of mass loading may help (sacrifice efficiency for a bit lower Fs). For example in a recent set of RS 40-1197s, coating the cones with puzzlecoat (primamrily to improve their sonics) also resulted in a lowering of the Fs a bit more than 10 Hz (from 104 to 93 Hz) with the sacrifice of 1.5 dB of efficiency.

The treatments also seem to raise the driver Q (ie reduce midband efficiency without lowering bass efficeincy), which will also lift the bottom a bit.

As to trying a bi-pole, since it seems the Z was designed by rote, and how a driver works in it is hit or miss, you may get lucky. From the ML-TLs that have emerged since Martin put these designs on the map (he didn't invent them, but did provide science to design them and really made people sit up & pay attention to them), my initial impression of the Z is that it is generally too long and not fat enuff, so adding a 2nd driver (ie a situation where it should be twice as fat) is intuitively going the wrong way (still do try it).

The elegance of the Z is its tallish slim appearance. My concerns could easily be met by making it deeper, and shortening the line by moving the port up, and leaving a sand-filled cavity at the bottom -- i suspect the mass loading of the bottom would have a beneficial effect all on its own.

For each driver you want to try a fresh line should be calculated using Martin's SW (we could have a whole family of Zigma-inspired designs)

dave
 
Lots of thinking..

Lots of suggestions, and more thinking for me to follow you guy.. (Planet 10)

Right now, I'll be off to a trip to New-England. Cant resist to the appeal of the sea..

It must be over 90'f right now. Whew..

Back to the Zigmahornets later. I'm not disappearing, just taking a vacation..

I'm still interested by the Foster horn tweeter..

Bye