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Multi-Way Conventional loudspeakers with crossovers

AE Lambda Midbass 10 Project?
AE Lambda Midbass 10 Project?
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Old 29th July 2008, 08:50 PM   #91
John_E_Janowitz is offline John_E_Janowitz  United States
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I looked into the Hiperco50(permendur) for the poles. It is VERY expensive. For 2" diameter bar stock it is around $230 per INCH! That means for the typical pole in the TD drivers we are at about $920 in raw material alone! It is also extremely difficult to machine and work with as it shatters and cracks easily.

For all practical purposes, the copper sleeve works well. Another option is to use powdered iron as it is magnetically permeable(although about 20% less than 1010steel) and non conductive electrically. Since we have more BL than needed in the higher diameter coil drivers, this can be a possible option as we get to those. The drawback is that you don't get the heatsinking ability with the powdered iron that you do with the copper sleeve.

John
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Old 29th July 2008, 08:59 PM   #92
SunRa is offline SunRa  Romania
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Quote:
I looked into the Hiperco50(permendur) for the poles. It is VERY expensive. For 2" diameter bar stock it is around $230 per INCH! That means for the typical pole in the TD drivers we are at about $920 in raw material alone! It is also extremely difficult to machine and work with as it shatters and cracks easily.
Crazy! And Feastrex is making monocoque motors entirely out of permadur. Of course, those units cost 7000 or so per piece.

Quote:
For all practical purposes, the copper sleeve works well. Another option is to use powdered iron as it is magnetically permeable(although about 20% less than 1010steel) and non conductive electrically. Since we have more BL than needed in the higher diameter coil drivers, this can be a possible option as we get to those. The drawback is that you don't get the heatsinking ability with the powdered iron that you do with the copper sleeve.
Just to understand. Moving magnetic field in the gap is an issue only when using conductive metals like steel as pole pieces? Or is it the fact that low content carbon materials like powdered iron, permadur have a better magnetic permeability? I guess any material used would benefit from the use of a copper sleeve, right?
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Old 29th July 2008, 09:22 PM   #93
SunRa is offline SunRa  Romania
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Am I getting close HERE ?

The yoke is 39mm or so, the VC would be 40mm. As you can see the yoke is larger at the base, and is copper plated. I can "cite" some of the sources for this design, but I couldn't test it yet with a FEM simulator. Don't have the time/knowledge.

The gap is 15 mm in length. This would qualify for an underhung design I guess. The yoke and the top plate ideally would be made of permadur. The rest is iron or soft steel. The outer iron rods are there for closing the magnetic circuit. The yellow ring would be the electromagnet. The cone is 12".

I drew these just for fun. I have to finish school first, get a home, and maybe then I'll try to build something . Until then, I'd rather purchase a TD midrange if I'll ever save some money .


EDIT: The yellow thin bar that exists the yoke is a heatpipe, as in CPU coolers. This would take the heat around the voice coil even faster than copper, and disipate it through a copper/al phase plug. Haven't seen this ideea yet. Maybe I'll patent it . Heat pipes can be used, if properly positioned, to greatly dissipate the heat in a motor like this.
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Old 29th July 2008, 11:48 PM   #94
tinitus is offline tinitus  Europe
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AE Lambda Midbass 10 Project?
Seems there is news on AE site
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Old 30th July 2008, 08:20 PM   #95
SunRa is offline SunRa  Romania
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I still found the TD series to be of great value after getting some details about them. Maybe the 10" drivers are a bit overpriced but still if you compare this with some of the European manufacturers pricing...
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Old 30th July 2008, 08:26 PM   #96
tinitus is offline tinitus  Europe
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AE Lambda Midbass 10 Project?
No no, with the care and technology going into these drivers I think they are very fairly priced, and should not be compared to TB drivers
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Old 3rd August 2008, 08:32 AM   #97
fivestring is offline fivestring  Slovenia
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Default Tang Band W8-1722

Quote:
Originally posted by LineSource

Here is the SPL graph for the Tang Band W8-1722 from the TB home site. There are some web reports that TB data is very optimistic, but it still seems useful to look at the 0, 30, 60 degree curves for this 8" for this discussion. The SPL looks like 87 db from the graph, but I don't know if this is "per watt" or at 2.83V. ...not high efficiency like Lambda target. This is a 4 ohm speaker. There is a diyAudio thread on these new TB underhung speakers and Zaph is starting measurements.
Hi linesource,

I can`t seem to find the data for Tang Band W8-1722, could you send me the link, please? Do you know who is selling them?

thanks
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Old 3rd August 2008, 11:34 AM   #98
LineSource is offline LineSource  United States
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Default Re: Tang Band W8-1722

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Originally posted by fivestring

Hi linesource,

I can`t seem to find the data for Tang Band W8-1722, could you send me the link, please? Do you know who is selling them?

thanks

http://tang-band.com/index.php?page=...3&lang=english


This site lists a 2 month delay until the W8-1722 ships. Listed at 89 Euros. zaphaudio.com is testing the 6.5" W6-1721 which Parts Express sells in the US
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Old 3rd August 2008, 03:30 PM   #99
fivestring is offline fivestring  Slovenia
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Default Re: Re: Tang Band W8-1722

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Originally posted by LineSource



http://tang-band.com/index.php?page=...3&lang=english


This site lists a 2 month delay until the W8-1722 ships. Listed at 89 Euros. zaphaudio.com is testing the 6.5" W6-1721 which Parts Express sells in the US
Thanks, but following the link I can`t seem to find any technical data nor graphs. Where did you find them?

regards
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Old 3rd August 2008, 04:44 PM   #100
LineSource is offline LineSource  United States
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Default Re: Re: Re: Tang Band W8-1722

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Originally posted by fivestring


Thanks, but following the link I can`t seem to find any technical data nor graphs. Where did you find them?

regards

http://attlid.eu/spam/W8-1722.jpg


This 2.3MB jpg includes T/S specs, SPL vs. freq, and distortion plots.
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