AE Lambda Midbass 10 Project? - Page 11 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 3rd August 2008, 11:27 PM   #101
SamL is offline SamL  New Zealand
diyAudio Member
 
Join Date: Jun 2004
Location: Wgtn
Default Re: Re: Re: Re: Tang Band W8-1722

Quote:
Originally posted by LineSource



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


This 2.3MB jpg includes T/S specs, SPL vs. freq, and distortion plots.
The DCR impedance is 3.6R. Not too good for those who plan to use two of them. 88db sensitivity is low for an 8".
The Jantzen Ja8008 by Seas has better sensitivity at 94/95db. Paper cone with foam surrounds. No mention about faraday ring. Can't find the price for them.
  Reply With Quote
Old 4th August 2008, 04:19 AM   #102
diyAudio Member
 
Join Date: Jun 2004
Location: Green Bay, WI
Send a message via AIM to John_E_Janowitz Send a message via MSN to John_E_Janowitz Send a message via Yahoo to John_E_Janowitz
Default Re: Re: Re: Re: Re: Tang Band W8-1722

Quote:
Originally posted by SamL

The Jantzen Ja8008 by Seas has better sensitivity at 94/95db. Paper cone with foam surrounds. No mention about faraday ring. Can't find the price for them.
This driver calculates out to 93.05dB 1W. I don't expect any shorting ring is being used, or if it is, it is clearly not effective based on the impedance curve. Also pay attention to the resonance centered about 900hz. It appears as a clear peak in the impedance curve and a dip in the response curve at the same point. Also the PDF file states "Be aware that normal box-simulations do not apply to this kind of driver." I'm curious as to why that would be?

We shouldn't be too far out on the 10" midrange driver. I have lighter samples of the 10" and 12" cones coming with a new material that Nick believes will be be best for the midrange. I will also be working on the 6.5" and 8" drivers soon as well. We really need a good, 95db+ 6.5" driver for 3way systems, and nothing I have tested is really up to par. If the cone samples prove acceptable I'll be on to those soon as well.

John
  Reply With Quote
Old 4th August 2008, 04:22 AM   #103
SunRa is offline SunRa  Romania
diyAudio Member
 
Join Date: Aug 2004
Location: Romania
Good luck with the testing!
  Reply With Quote
Old 4th August 2008, 05:52 AM   #104
diyAudio Member
 
LineSource's Avatar
 
Join Date: Sep 2003
Location: SiliconValley
Default Re: Re: Re: Re: Re: Re: Tang Band W8-1722

Quote:
Originally posted by John_E_Janowitz
We shouldn't be too far out on the 10" midrange driver. I have lighter samples of the 10" and 12" cones coming with a new material that Nick believes will be be best for the midrange. John

John - Nick....Please consider prototyping a 10" underhung motor midrange with a 0.85" thick AlNiCo ring magnet in place of the current ceramic. It sounds like your magnet charger equipment is adequate to handle AlNiCo. The increase in gap flux will acheive the required BL at lower Mms and higher Xmax from a shorter-lighter copper voice coil, and AlNiCo has better resistance to reverse EMF flux drop. Can you prototpye a thicker rear pole steel which seems to saturate first?

SamL...a solid state diy'er could build a 25W super-sym Class-A amp that could easily drive a 1-2 ohm load of two W8-1722 in MTM parallel with 99 db/watt efficiency. This could mate to a 99db/watt diy ribbon tweeter with 2-ohm transformer. Small wattage Class-A bipolar amps sound sweet to my ears.
  Reply With Quote
Old 4th August 2008, 08:34 AM   #105
diyAudio Member
 
Brett's Avatar
 
Join Date: Jan 2002
Default Re: Re: Re: Re: Re: Re: Tang Band W8-1722

Quote:
Originally posted by John_E_Janowitz
We shouldn't be too far out on the 10" midrange driver. I have lighter samples of the 10" and 12" cones coming with a new material that Nick believes will be be best for the midrange. I will also be working on the 6.5" and 8" drivers soon as well. We really need a good, 95db+ 6.5" driver for 3way systems, and nothing I have tested is really up to par. If the cone samples prove acceptable I'll be on to those soon as well.

John
Damn. I haven't even got my 10M's yet and you're coming out with a higher efficiency version. I'm going to have to watch out for those as the 10M's will only be>250Hz in my system.
  Reply With Quote
Old 4th August 2008, 11:39 AM   #106
SamL is offline SamL  New Zealand
diyAudio Member
 
Join Date: Jun 2004
Location: Wgtn
Default Re: Re: Re: Re: Re: Re: Tang Band W8-1722

Quote:
Originally posted by John_E_Janowitz


I will also be working on the 6.5" and 8" drivers soon as well. We really need a good, 95db+ 6.5" driver for 3way systems, and nothing I have tested is really up to par. If the cone samples prove acceptable I'll be on to those soon as well.

John
A 6.5" will go very nicely with one of your TD12 in a 3 way. The 8" will be nice for OB mid ... you going to make us drool.
  Reply With Quote
Old 4th August 2008, 04:36 PM   #107
diyAudio Member
 
Join Date: Jun 2004
Location: Green Bay, WI
Send a message via AIM to John_E_Janowitz Send a message via MSN to John_E_Janowitz Send a message via Yahoo to John_E_Janowitz
Default Re: Re: Re: Re: Re: Re: Re: Tang Band W8-1722

Quote:
Originally posted by LineSource
John - Nick....Please consider prototyping a 10" underhung motor midrange with a 0.85" thick AlNiCo ring magnet in place of the current ceramic. It sounds like your magnet charger equipment is adequate to handle AlNiCo. The increase in gap flux will acheive the required BL at lower Mms and higher Xmax from a shorter-lighter copper voice coil, and AlNiCo has better resistance to reverse EMF flux drop. Can you prototpye a thicker rear pole steel which seems to saturate first?

SamL...a solid state diy'er could build a 25W super-sym Class-A amp that could easily drive a 1-2 ohm load of two W8-1722 in MTM parallel with 99 db/watt efficiency. This could mate to a 99db/watt diy ribbon tweeter with 2-ohm transformer. Small wattage Class-A bipolar amps sound sweet to my ears.

We will be doing Alnico options for all the TD drivers some day. It may be 6-12mos out though. As far as a .85" thick Alnico ring goes, that wouldn't be too practical. Alnico needs to have at least at 4:1 height to diameter ratio or it will short itself out. So if this was the case, you'd only be able to have about .21" thickness to the ring and not be very practical. We have 2 sizes we're working with. One is a 4.5" OD x 3" ID x 1.75" tall. The other is a 3" OD x 2.25" ID x 1.5" tall. These 2 sizes give us many options for both 2" and 2.5" coil drivers. Adding an additional disc of alico to the pole if/when needed gives us further ability to get the correct amount of flux in the gap.

Also, the Alnico won't give us different parameters or increase in flux compared to the ceramics. We can get any parameters or any amount of flux in the gap we want with either the Alnico or ceramic, or neo if we had a magnetizer to do that. The limit is simply the pole saturating before anything else. The only option from there is to go with a larger diameter pole to have more steel available.

Again, in your FEA from before, you are looking at only a 2d snapshot of the driver. You can't use it for BL comparisons between ceramic, neo, alnico. Without a 3d model you will get results like you are showing where the base of the back plate saturates first, but in reality it is the pole that is first to saturate. FEMM is good only to determine how linear your flux will be in the gap, but can't give you absolute flux comparisons for a 3d part.

John
  Reply With Quote
Old 4th August 2008, 04:39 PM   #108
diyAudio Member
 
Join Date: Jun 2004
Location: Green Bay, WI
Send a message via AIM to John_E_Janowitz Send a message via MSN to John_E_Janowitz Send a message via Yahoo to John_E_Janowitz
Default Re: Re: Re: Re: Re: Re: Re: Tang Band W8-1722

Quote:
Originally posted by SamL

A 6.5" will go very nicely with one of your TD12 in a 3 way. The 8" will be nice for OB mid ... you going to make us drool.

The 6.5" was the problem we ran into in doing a 3way as discussed here:

http://www.avsforum.com/avs-vb/showthread.php?t=1035126

We planned on a 6.5" to cover approximately 300hz to 3KHz, but just can't find any 6.5" that can cover the range and sound as good as the TD10M, 12M, or 15M. We simply have to make one as nothing available measures up. We will also be doing some waveguides in the future allowing for some very nice 2way systems. A TD12M mated to the 12" round waveguide for example or a TD15M mated too the 15" round waveguide would be an extremely simple solution.

John
  Reply With Quote
Old 4th August 2008, 10:36 PM   #109
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
I understand the need fore a 6" hifi mid with say 93db sensitivity

But fore a higher sensitivity mid B&C 8PE21 could be the one to beat

http://www.bcspeakers.com/index.php?...e=2&prodotto=3

A smaller neo magnet would be good at making a more open back
Also the B&C has short +/-1mm Xmax, double that would be better or maybe underhung even better
But I like that it rolls off by itself in the 250hz region...I have plans fore that
__________________
sometimes we know very little, and sometimes we know too much
  Reply With Quote
Old 4th August 2008, 11:46 PM   #110
diyAudio Member
 
Join Date: Jun 2004
Location: Green Bay, WI
Send a message via AIM to John_E_Janowitz Send a message via MSN to John_E_Janowitz Send a message via Yahoo to John_E_Janowitz
Quote:
Originally posted by tinitus
I understand the need fore a 6" hifi mid with say 93db sensitivity

But fore a higher sensitivity mid B&C 8PE21 could be the one to beat

http://www.bcspeakers.com/index.php?...e=2&prodotto=3

A smaller neo magnet would be good at making a more open back
Also the B&C has short +/-1mm Xmax, double that would be better or maybe underhung even better
But I like that it rolls off by itself in the 250hz region...I have plans fore that
We looked at the B&C's. In this case, there isn't really a benefit to the 8" B&C over our TD10M. You don't gain much in going from one size to the next in terms of off axis response. The inductance on the B&C is also double that of all the TD drivers and more than 4X what our midrange drivers will be.

If you look at the B&C 8PE21 impedance curve there is a big bump just below 1Khz and another at just under 3KHz. The one at 3KHz corresponds to the bump in the response curve. I'd also like to see what an unsmoothed response looks like. The copper cap helps a little, but not nearly as much as a full copper sleeve because inductance is still going to vary with excursion. The B&C may be better than most but still leaves a lot of room for improvement.

john
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: 1 Lambda TDX15 JoshK Swap Meet 5 10th November 2006 12:05 AM
Sub for Lambda PMD17K100 Grumpy_G Pass Labs 2 7th January 2006 07:49 PM
lambda dipoles jonk Multi-Way 1 6th March 2003 04:04 PM


New To Site? Need Help?

All times are GMT. The time now is 12:29 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2