Jay_WJ said:
..and from what I remember Unibox is a more accurate modeler.
Also,
Ceibal, don't forget that the low freq. response will actually be more "extended" than what Jay has in that graph. With moderate BSC and room gain you are basically flat to 60 Hz with a -3db point somewhere between 40-50 Hz and a lot of near level extension below that.
Ceibal said:
Like many of the people on here, I agree that trying to design the "ultimate" speaker as a first project is a recipe for failure.
Here's how it happened when I tried that.
I was nineteen years old and I discovered Madisound and Old Colony Sound Lab. I spent weeks poring over their catalog, and wound up buying a program called Calsod for designing crossovers. After ingesting the Loudspeaker Design Cookbook, I decided that 4th order crossovers were necessary.
I designed the speaker on the PC using Calsod, purchased the crossover parts from Madisound, put it all together...
And it was unlistenable. It was just complete crap.
So... Believe me, I've been there
Nonetheless, more than a decade later, I'm still at it.
I personally find that the funnest projects are clones. Right now I'm trying to clone a unity horn (again.)
another stab at a unity horn
If you like the Dynaudio designs, you might consider the kits from GR Research. Both companies offer designs with a lot of "slam" and dynamics. Danny, the designer, is also a great and supportive guy.
ScottG said:
Exactly.
The real problem however is that it a re-occurring theme.
With the exception of naïveté with regard to bass extension vs. enclosure volume (sealed vs. vented), what he wants (the end result, NOT a sealed design and some boutique parts selection) is actually do-able at a reasonable price - but I don't know of such a design and I'm not sure there even is one.
Sadly it makes me want to do such a design, BUT I know that I neither have the time nor will I spend the cash on something that I know is no longer what *I* really want.
So the best I can do is offer up a fairly quick suggestion of what I think that person should do based on a guess that *belies* just how much knowledge goes behind that suggestion.
....
What I think is particularly ironic here is that Shin has questioned me on the selection of the Neo 3 pdr. (..don't mind the questioning, but I do appreciate the irony.
It wasn't *that* long ago when he went through something not altogether dissimilar to this poster's dilemma. While he avoided many of the crossover issues by going digital, there were still many costly driver swaps that occurred - driver swaps well beyond the financial abilities of most DIY'ers.
For most people then in a similar situation it means buying these drivers and being stuck with them and no viable loudspeaker (..i.e. the "wanting everything and ending up with nothing").
And seemingly the pinnacle of this "diy driver bane" are the Seas EXCEL magnesium drivers.
Superbly designed,
Superb measurements,
Good looks,
Detailed sound,
..oh, and ultimately worthless for long term enjoyment (..funny how this just doesn't seem to get through
-and so we go round and round again.
Wanted to know why the Seas Mags were not any good for long term enjoyment?
Also, what is your opinion on using Madisound to design the crossover? I figure for $30 it might just be worth letting them do it instead of me investing a grand or more in software. I will still learn allot by putting the crossover together myself.
I am leaning toward the Scanspeak 18w/8535. They have a QTC of .71 in a 1 cubic foot box. Of course, I have not taken into account the damping material. If I am right, this will raise or lower the QTC and FCB?
Ceibal said:
This is not the best way to design and build a speaker - starting with the box and selecting drivers to suit is not optimal. Why not build your own enclosure?
A better approach (if you can't build your own box) is to go with an established design that will work in the box size you want or smaller. You can then add material to the inside of the box to reduce volume.
Jay_WJ said:
More importantly it doesn't take into account higher freq. irregularities (vs. Infinite baffle) caused by the baffle itself.
i.e. its a VERY bad idea..
Again Ceibal, we have given you the only really good short-cut there is - go with a proven design.
The excel drivers are not very dynamic unless your partnering amplifier has a *lot* of current capability. They also sound restrained/constipated, aka - overdamped. Then there are the problems of crossovers with them.
I've given you everything you need to make an informed decision, so I'm done with this thread.
Don't know what the budget is but 2000 euro's get you>
http://www.audax-speaker.de/ibase/module/medienarchiv/dateien/Fotos/pro20d.jpg
http://www.audax-speaker.de/content.php?seite=shop/produkte.php&hauptrubrik=2&details=83
BG neo3, BG neo10, Usher W 8137.
http://www.audax-speaker.de/ibase/module/medienarchiv/dateien/Fotos/pro20d.jpg
http://www.audax-speaker.de/content.php?seite=shop/produkte.php&hauptrubrik=2&details=83
BG neo3, BG neo10, Usher W 8137.
ScottG said:
They use LEAP 5 don't they?
I use this too and its a two fold program - first is Enclosure Shop used to create a 3d representation of the enclosure and second is Crossover Shop which works much like lspCAD, Soundeasy etc. The thing is that Crossover Shop models baffle diffraction, baffle step and so on based on the model of the enclosure done in Enclosure Shop - something no other program does.
Its not infallible but is ahead of the basic crossover modelling capabilities of lesser programs like Soundeasy etc. Only problem is LEAP lacks the ability to measure, it can import data of course. It doesn't really need measurement capabilities though since it aims to provide accurate models without you ever having to build a box - just be sure that the raw data for the drivers your using is sound.
Your probably right though. It takes hours to come up with a fully involved and accurate model. Can't see them taking the time to do that when they're only charging a small amount in the first place.
Two things...for the thread starter
One: As far as the seas mag's are concerned....have you heard them in any commercially available speakers? You site Dynaudio as an interest and like others, I would point you to Audio Technology or Morel for a like cone material and sound. The Seas are different. All speaker cone materials have a sound....and the mag's are going to be way different the poly. If you go poly, Troels and Tony both have good designs. If you go Seas mag, Troels has quite a few there as well.
Two: Going sealed. Many woofers that are "suited" for ported alignment work fine in sealed enclosures. I much prefer the sound of sealed enclosures for bass regardless of the extension (and noise) provided by ported boxes. The rolloff is slower and the sound to my ears is preferable. You can always sacrifice efficiency for extension and have a lower f3 and buy a bigger amplifier. (Quality and quatity) Watts are a lot cheaper than they used to be.
C
One: As far as the seas mag's are concerned....have you heard them in any commercially available speakers? You site Dynaudio as an interest and like others, I would point you to Audio Technology or Morel for a like cone material and sound. The Seas are different. All speaker cone materials have a sound....and the mag's are going to be way different the poly. If you go poly, Troels and Tony both have good designs. If you go Seas mag, Troels has quite a few there as well.
Two: Going sealed. Many woofers that are "suited" for ported alignment work fine in sealed enclosures. I much prefer the sound of sealed enclosures for bass regardless of the extension (and noise) provided by ported boxes. The rolloff is slower and the sound to my ears is preferable. You can always sacrifice efficiency for extension and have a lower f3 and buy a bigger amplifier. (Quality and quatity) Watts are a lot cheaper than they used to be.
C
ShinOBIWAN said:
Its been more than a few years since I last inquired (though they were using LEAP then) - so it could have changed..
BUT when I did, I got the distinct impression that the design process was not nearly so accurate and rigorous as suggested by their advertising "blurb".
Notice that NONE of their 5 questions encompass baffle shape:
1. What drivers are you using? They must be Madisound stock items.
2. What are your box volumes, or do you wish us to determine them for you?
3. Are the drivers surface mounted, or routed into the cabinet for a flush mount?
4. What slopes (6dB, 12dB, 18dB, 24dB) would you like us to design for, or would you prefer we choose?
5. What quality of inductors will you use? We will model using the DCR of the coils.
However, because they also sell cabinets - they might actually integrate their crossover service for those cabinets (..obviously best to ask about that). Their MD20B cabinet *appears* close enough in shape that it should be fairly complementary to the PE curved cab.
ScottG said:
Agreed. The original poster should check to see what the service covers. If its just based on modelling of manufacturer IB FR and Re data then forget about it. You might as well buy one of those generic off the shelf crossovers as it would only be marginally worse.
I hope that isn't the case though, since LEAP is quite capable of an accurate model that encompass virtually all aspects of a design.
ScottG,
Please elaborate on this comment from post #42 regarding volume and damping:
The Neo 3 pdr will provide some of that magic (like the RAAL), that isn't easily "seen". In this case its enclosure volume is fairly critical - other wise it becomes overdamped (if its to large), and you loose that magic (..and you might as well look at something like the Seas at that point).
I thought that the smaller the enclosure the greater the damping. Please elucidate.
Thanks,
Ray
Please elaborate on this comment from post #42 regarding volume and damping:
The Neo 3 pdr will provide some of that magic (like the RAAL), that isn't easily "seen". In this case its enclosure volume is fairly critical - other wise it becomes overdamped (if its to large), and you loose that magic (..and you might as well look at something like the Seas at that point).
I thought that the smaller the enclosure the greater the damping. Please elucidate.
Thanks,
Ray
Ray Collins said:
Basically with overdamped drivers the larger the enclosure volume the less the driver reacts to that volume's air load and the more it reverts to its overdamped nature. That volume air load acts like a cushion that keeps it from returning to it natural position as quickly as it ordinarily would - so the driver has additional "hang time" (or decay).
Ray Collins said:
On tweeters and small midranges its a matter of trial and error - you simply listen for the difference. Same goes with fiberfill quantity and placement - IF ANY. In fact this is THE major area that separates a premium tweeter from a cheap tweeter. More costly tweeters typically take a good cheap tweeter and then tweak its rear chamber to achieve better compliance and airflow in the rear chamber without "hurting" the CSD too much (..i.e. removing fiber almost always "hurts" the CSD).
..and on that note:
I'd be willing to bet that the Peerless HDS tweeter could be improved to the point where it would sound better than just about any normal tweeter on the market regardless of price.
..but this is all kind of off-topic, so I'll stop here.
Ceibal said:
I'm just now getting into this thread and it sounds as if you are catching on to what folks are telling you. I started messing with speakers in the later 60's and have heard just about every brand and configurarion out there. I use SE and several other programs when building and then use my own judgement as to configuration. Some times it works, ans sometimes it doesn't. And I still have all the old time measuring gear, scopes signal generators, meters etc. etc.
The specs alone will rarely get you what your hoping for, takes a lot of tweeking and measurement. Many folks have done that for you, take their design and play with it and go from there. I have a whole room full of drivers some old, many new, no two sound alike, even though the specs may be very close and or simular.
Trying to fit the speakers for the box can be a tough one. I live near a little town called Bridge City here in the Republic of Texas. If you are near enough, I can toss together some boxes for you. I have all the needed gear and don't mind, I spend most of my evenings in the shop making saw dust any how.
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