Poly Natalia’s Possible or just crazy?

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I have been considering building the Poly Natalia’s. The design was very close to something I have working on now for sometime and thought that this would be better for me for my first time project then my own design. I have read everything I could about them but everything I see seems to be that they should be used with Tube amps also by the looks of the crossovers it would appear that they are tri-amped. What I need to know is should these work well with transistor amps too. I have both an Adcom GFA 585 and a GFA 5800 now and will most likely be looking for another amp as well which I have not decided on yet. I am building 2 Isobaric subs using 2 Dayton Part # 295-185 dual VC per seal enclosure. I guess my question is simply this can I make all this work and what changes would I have to make in the Poly Natalia’s? Can these be made to work with just the 2 amps I have now by adding to Adcom GFA 565’s to dive my subs with a Paradigm X-30 Subwoofer Crossover or something like it and then either actively crossing the PN’s or modifying the passive crossovers in the PN’s to work with 1,2 or 3 amps. It has even crossed my mind to use a tube amp for the tweeters or Tweeter mid combo. Any help or ideas with this project would be much appreciated before I spend a bunch of money on something that just doesn’t work.
TIA
 
Hi,

seems to me with stereo subs you are planning on building entirely
the wrong sort of loudspeaker - the PNs design implies very good
bass extension with an extended bass alignment to well below 30Hz.

Also the crossover design in no way implies they are tri-amped.

For stereo subs you should be looking at something like a sealed version of this :

http://www.humblehomemadehifi.com/DD8-MkII.html

:) /sreten.
 
Fearless,

I agree with sreten. If you build your good pair of stereo subs all you need to add is a pair of MT speakers.

PolyNatalia was an excellent system in its day and was well introduced and advertised, but it is now ancient history. Audax has stopped selling drivers into the retail/DIY market, the exact Audex drivers used in the PN no longer are available. The Morel MDT-33 tweeters are excellent although many builders now prefer a Seas tweeter which is cheaper.

I built the PN and am still using a version of it. I replaced the orginal HM210ZO drivers with HP210Z2 (they had a better upper range) and am using them with a pair of stereo subs, and the system sounds very good with solid state amplifiers. I am using a series 3-way 1st order xover on them. However, I would not repeat the process to build this system.

Go to Madisound message board or search here for speaker kits from people such as Dennis Murphy. There are lots of projects available and all details are published for free.

My $0.02 ;)
 

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Well the subs are not something I am going to change as the 4 drivers are sitting here on the floor next to me, so I am glad I asked. The main reason I had thought the PN would suit me was mostly design and the drivers have become available used and could be built reasonable. So I think the best thing for me to do now is go back to the drawing board with own design as it was more close to what you have said in the first place. I would also say I would prefer that because of the pride of it being mine. I was just getting frustrated with having limited computer software to model the total enclosure as I only have bass box to work with and nothing to model the crossover.
In my first mid bass design I was using a pair Usher 8945P 7” in about 1 cu.ft ported enclosure as it seemed to roll off on the low side just about where I wanted it to at about 100 hz just where I thought I should cross it over. And it also would extend high enough that making this a two way would be easy enough but the guy here in the trading post that had them turned out to be a bust and sent me looking for the next deal I could find to do this with some kind of a budget. I had also considered 2) Eton 8-800/37 HEX in a VB 0.725 cu.ft sealed box or 2) 7-360/37 HEX in a VB 0.518 cu.ft ported enclosure with 2.5” X 7.75” single port. It would appear to me these should all work well to become part of my total enclosure with my subs. I also thought I would like to top it off with the Vifa XT25TG30-04 tweeters being that these would also keep me the 4 ohm impedance that I had wanted. All of these options here would mean paying the long $ as no deal have yet to found at this point. One more thing as I have been considering the purchase of Winspeakerz to aid me in my efforts to build the better mouse trap. Do you think any of these could do the job I am looking to do?
 
A speaker system is called a "system" because all of its parts must work together in a precise manner. The design of the crossover is the most important part. Unless you have had a lot of experience designing and tweaking crossovers you should build a kit or follow a published design. Without measuring equipment and crossover simulation software your efforts will not be the best. It is better to follow a published design than it is to try and buy this or that driver and get them to work together.

Box modeling software for the woofer's match to the capinet is simple. Designing a xover for the MT or WMT is the difficult part.

Check out the stuff from Dennis Murphy. Again, my $0.02:angel:
 
Dick West

Well this seems to be very discouraging and also lacking adventure and lacks learning as in my life I have taught myself 2 different trades auto mechanic and computer tech and in both I was very good not to blow my own horn but to not try would have brought nothing to my life. I am not in this DIY just to be a kit builder. I would rather take my chances and fail to try again. I have had some great people here help me in the past and I am grateful always, but I have a will so there must be a way!! Hay and what the H*LL maybe I have some fun too. I hope that this project will be the first of many so left over drivers may just end up in some other project I get whim to try. Look I could have built the PN kit and had the same thing but you guys here saved my neck from a disaster but this I can say I learned something. Thanks
 
Unless you have had a lot of experience designing and tweaking crossovers you should build a kit or follow a published design.

Whilst i partially agree, in that a first project should probably be a published design or kit, without getting your feet wet at some point you will never achieve "a lot of experiance designing and tweaking crossovers", however i wouldn't recommend doing this with expensive drivers to begin with.
 
Hi Fearless,

Speaker building can be an itch you've just got to scratch. Aim as high as you like, use whatever drivers you fancy; if you dont you will always be wondering "what if.."

The real experts will get the most out of any given parts, but you can go a hell of a long way with an spl meter, test tones, a good set of ears and the drive to modify, rebuild and constantly tweak.

The advice above is sound- build a dennis murphy design and you'll have an excellent speaker. But it won't give you the fun of your own design from scratch.

A good reality check is to keep a reference speaker for comparison, or compare to a friends. This can show up weaknesses in your design that you can "tune out" thru familiarity.

Go for it:smash:

All the best
 
Nowdays when speaker modeling/measuring/crossover design software is so available and relatively inexpensive it is silly to just forge ahead and build without measurements and simulations.

I understand the thrill of DIY and satisfying an itch, but building the "newbie amateur" may drive one to distraction. Tweaks and concerns about "did I get it right" will eat up endless amounts of time and costs for coils and caps will mount and mount.

If fearless really wants to learn another trade he should begin by studying and obtaining and learning to use the design tools available, then he can make his own speaker systems and know that they are good.

Now, I speak from experience, but currently don't follow my own advice. I purchase drivers known to be very robust and broadband and suitable for serial networks. Then, I use some design tools available to make the first iteration of the crossover. Then, I attach the emergent xover to the drivers with wires long enough to put the xover on my coffee table. Then, I can tweak it by changing values of coils and caps in almost real time. This is my compromise, my performance standards are not that great, and this works for me. I do this only because I already have accumulated lots and lots of parts from my amateur trial and error days. If I were starting over again I would concentrate on cabinet beauty and build kits -- OR -- begin by learning to use the professional tools of the trade that are so readily and cheaply available.

But, a man convinced against his will is of the same opinion still. :idea:
 
Thanks to All: I DO BOTH!

Ok I would like to thank (float) for your encouragement and everybody else for being the Devils advocate so I will do both. I am going to build one kit or plan design for my center channel that I saw on Parts Express
Link http://www.partsexpress.com/projectshowcase/cynosure/index.html
Only for the sake of getting my feet wet and the fact is I need a new one and I am not very concerned with my video equipment as my audio and don’t really have the passion for the design for AV stuff.
But my need to do this for myself in folly or not just has to be. I just hope before I am done that everybody doesn’t want to run for the hills when they see I am asking more questions.
I will need better modeling tools. I have Leap but it’s to advance for me yet at this point and Bass Box just is not complete, while great for box modeling to a point it just can’t model the total enclosure and crossover. I am planning to purchase Winspeakez if anyone thinks this should help or any other software that has at lest a bit of use friendliness to it. I also have RTA for analyzing the prototypes. I am buying whatever books I can get my hands on to learn all I can but I have always had to put what I read in my hands before they sink in. I have been searching the web night and day reading every design I can find hoping to learn all I can from published designs.
I have been into car audio before it was cool or even know much about I have did professional sound work on soundboard for 3 years working 1500 watt system for our band including its repairs. While being new to DIY here I am not new to it in Pro Audio working with Active crossovers so if the crossovers get in my way so be it there is more then one way to skin a cat. I will just go active and use my ears just the way I did on my board. I have also heard that Madisound does offer Leap design for crossover if you use speakers they stock? If this is true then what the worst that can happen?

One more thing is I don’t just need another pair of speakers I need something to ROCK THE HOUSE!!!!! I am used to volumes that would dive most audiophiles out of thier minds for 5 days out of week sometimes. While image and pure sound is so important to most when I hear a bass drum kick I want to feel like my heart just got punched into the next county! Now I am sure this will get raise out of someone but please it’s just the reason I got into DIY because NOBODY DOES IN MY WAY. If I thought there would be some gain to build some kit that handles a 100 watt just for fun then what do I do with them drivers use them for my Ipod even that gets a Hafler dh 500 to drive it for use as my clock radio.. Now if I end up with a pile of high end, high power stuff now my leftovers got some use for something I may want to get real crazy with.

Sorry for the rant but I really want to get down to business.

What do you think about the Eton drivers and Vifa tweets? (System must end up at 4 ohms or less cabinet must handle 250 to 300 watts) Remember my subs are set up to handle 700 each driven with 2 Adcom GFA 565 and I have 2 amps left for this project a GFA 585 and a GFA 5800. I am tending to the 2) Eton 8-800/37 HEX, but the 2) 7-360/37 HEX look just as good to the crossover point I want to have.

What’s the best modeling software you think could help me?

What some good reading, web or books?

The room this will be used in if it helps is about 18 X 22 with 20” ceiling
 
Re: Thanks to All: I DO BOTH!

Fearlessleader1 said:
[B

What do you think about the Eton drivers and Vifa tweets?

What’s the best modeling software you think could help me?

What some good reading, web or books?

The room this will be used in if it helps is about 18 X 22 with 20” ceiling [/B]


I think eton make good woofers and decent but tricky to use mids. The vifa xt25 is a good and popular tweeter.

Search for 'FRD consortium'. Unibox is a good bass tuning program and PCD seems ok for xo's. Haven't used leap, so cant compare. Simulators only give you a starting point anyway; its the measuremnet, tweaking and listening that matters.

As far as reading goes; this forum, htguide, zaphaudio, murphyblaster (all .com) should keep you out of bed for days...:D
 
diyAudio Member
Joined 2004
Another important point is that you don't need to be a dinosaur and prototype an XO using passive components the could take forever to swap around.

Buy a Behringer DCX2496 and use active electronics to make changes in 'proper' realtime ;)

After this you can transfer this to a passive network or maybe you'll be happy leaving the DCX in place.

It sounds like your heart is in this and that's the most important thing. I personally started off with a Visaton Topas kit but all I really learned was cabinet making. Which is the important point - you don't learn about the important design issue's with a kit, its all the pratical stuff you gain knowledge in and the theory remains partially obscure and unpracticed.

Go with a kit if you want an easy life and a point of reference for future home brew design but TBH it sounds like your should just jump in. Get some decent modelling software such as lspCAD, speakeasy or speaker workshop and start modelling potential designs with manufacturer Thiel/Small specs. Play with the XO components to see what happens to the response and what you have there is more hands on experience than ANY kit will offer you. Also buy a couple decent books such as

The Loudspeaker Design Cookbook' by Vance Dickason
Speaker Building 201 by Ray Alden
Introduction to Loudspeaker Design by John L. Murphy

Out of those the most accessable is the the John L. Murphy one. The Loudspeaker Design Cookbook is a great read though so I'd get both if your serious about this.

Like I said build a kit if you want an easy life but go with a home brew if you actually want to learn something about the inner mechanics of a loudspeaker.
 
PCD and Unibox are very fine and very easy to learn and work with. Regarding enclosure calculations, Martin King’s mathcad based models are more precise from Unibox, but Unibox is friendlier if someone has to look after many drivers. FRD consortium has great (mostly excel-based) utilities. Leap is a lot stronger, both the enclosure and crossover workshop. Calsod (for crossovers, Dos-based) is perhaps even stronger (IMO) in some aspects (for instance in the way you can work with power response and off-axis responses), if someone spends some months to learn it, but Leap, as a windows-based program which is also capable of inputting data in various format, is probably the best deal for a professional. For the amateur, I would suggest a look in FRD consortium.

Regards,
Thalis
 
ShinOBIWAN

ShinOBIWAN said:
Another important point is that you don't need to be a dinosaur and prototype an XO using passive components the could take forever to swap around.

Buy a Behringer DCX2496 and use active electronics to make changes in 'proper' realtime ;)

After this you can transfer this to a passive network or maybe you'll be happy leaving the DCX in place.




Now here is some logic I can relate too!! This should do real nice to work with things I know about to aid me with things I don’t. I have seen a few bit lower end models that I would be a bit more familiar with like the BEHRINGER CX3400 and it could be had real cheap but I do see the DCX2496 is a real trick unit for about $250 on the web new. Also from what I could tell it has some import and export software too. Sounds like a computer geek like me could have some fun with that!!

One more thing that seems real good about that is it works for every whim I may get a mood to play without the hassle of having parts on hand just to try a box and driver combo for fun.

I am on the books too!! have some already too.

Thanks sounds like your a person that thinks a bit like me.
 
Re: Re: Thanks to All: I DO BOTH!

float said:



I think eton make good woofers and decent but tricky to use mids. The vifa xt25 is a good and popular tweeter.



With this in mind would you recommend any other driver with good power handling and keeping in the same quality level? What would be better to use as mid bass drivers. I would like to stay with 2) 7” or 2) 8” drivers. I would prefer to stay with sealed box with my first solo effort and with this size driver I won’t need it to go down in the basement on the low side but it’s got to get up high enough on the high side to reach a good point to cross with the tweeter I have chosen. I also need to keep my box size small enough to work out in the end to have a total enclosure at a reasonable height and I would think whether it would be MTM or MMT would both be fine as long as my tweeter stays at ear level. That was some of my reasons to prefer either of the 2 Etons drivers. I have about 16” of bottom cabinet but could be resized easy enough but not less then 13” I would think.
 
thalis said:
PCD and Unibox are very fine and very easy to learn and work with. Regarding enclosure calculations, Martin King’s mathcad based models are more precise from Unibox, but Unibox is friendlier if someone has to look after many drivers.

Regards,
Thalis


Ok I have Mathcad as when I first started into DIY I thought I would build Transmission lines but after seen the cabinet work and the calculations figured I should get that right out of my head at the beginning.

I am looking into Unibox but I can’t find anything about PCD.

I have Leap 5 or 6 I think but when I open the bad boy my eyes hang on my cheek. :bigeyes: I can’t even think where to start to input data and drivers, but I do believe it to be the most robust program that can be had. Just now I need a bit more user friendly.
 
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