Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

TDL Studio 3 crossover upgrade is better and yet worse as well
TDL Studio 3 crossover upgrade is better and yet worse as well
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 23rd February 2017, 05:12 PM   #11
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Location: Portsmouth UK
The schematic helps a lot!

I'm guessing these are 16 ohm polycones, but I don't think my rough sim is much affected. I know this territory.

I can't see much point in messing with the bass filter. It's the sort of thing that works well with polycones, which really don't need much work.

The sim shows the single cap tweeter filter in dotted. Also a conversion to third order and zobel. A 7.5R/0.68uF Zobel is just something I like with metal domes, and tames the top end a tidge, and you can try that without changing the rest of the filter.

You could try 4.7uF/0.3mH second order too, without the 10uF. This sort of thing changes the character of a speaker. But definitely lower tweeter distortion, which can be good for complex orchestral music. You keep the 2.2R at the input, because it protects the amplifier from overly low impedance if the tweeter blows.

So there it is. Things to try.
Attached Images
File Type: png TDL Studio 3 Original Filter.PNG (6.6 KB, 216 views)
File Type: png TDL Studio 3 Suggested Filter 3rd order.PNG (7.0 KB, 160 views)
File Type: png TDL Studio 3 FR.PNG (25.5 KB, 160 views)
__________________
Best Regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 23rd February 2017, 06:05 PM   #12
eriksquires is offline eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
Try returning C1 to it's original.

Usually this cap has a high ESR to begin with. To replace it properly you need to measure the ESR and compensate for it in the series resistor.

This is an unusual case however, as that 10 Ohm resistor in series normally would prevent you from making too big of a mistake. Often this is in the 1-3 Ohm range, and so a change in ESR of a couple of Ohms can make a bid difference.

Best,


E
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.
  Reply With Quote
Old 23rd February 2017, 06:17 PM   #13
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Location: Portsmouth UK
Looking at the schematic, Erik, I wouldn't expect much difference in the bass shunt performance with ANY capacitor type change. With 10 ohms there already.

Click the image to open in full size.

Treble level might jump a dB with a polypropylene replacing a Non Polar.

I used the big ones recently, just because I have them. And they sound good.

Click the image to open in full size.

BTW, if you end up with a glut of 12uF, you could easily use them in a 4.7uF/0.3mH/12uF tweeter filter. These values just aren't very critical.
__________________
Best Regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 23rd February 2017, 06:53 PM   #14
eriksquires is offline eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
Well, I did say it's a very unusual case, but the audible symptoms are kind of similar.

The issue isn't bass, but rather, treble impedance.

Like you point out, with a 10 Ohm resistor in series this would be extremely unusual, but I thought I would mention it just in case.

Best,

E
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.
  Reply With Quote
Old 24th February 2017, 12:13 AM   #15
irishiranian is offline irishiranian  United Kingdom
diyAudio Member
 
Join Date: Mar 2010
Thank you both for getting back so swiftly. Truth be told I only have half or maybe a third of a clue what you have both written but I guess that's how we learn things right!? I can follow the new schematics and have a rough idea of what concepts you are sharing. I'll have another tinker and then report back (probably with more questions)!

Have just put the jenzen 3.9 back on the high pass as the other was too awful to keep in...ever used an iec cap before? Im not a fan... Thanks again for your time.
  Reply With Quote
Old 24th February 2017, 01:01 AM   #16
Dissi is online now Dissi  Switzerland
diyAudio Member
 
Join Date: Sep 2012
Location: Winterthur
Hi Christian,

It's actually quite easy. It's the resistor in the woofer filter that rules the midrange level. With 10 ohms you get a broad dip of 5 dB at 1.7 kHz and the mids are muffled. With 1 ohm the mids possibly are a bit exaggerated. I assume 2.2 ohms is about right.

Please check your original crossover. I don't believe the resistor really is 10 ohms.
  Reply With Quote
Old 24th February 2017, 09:50 AM   #17
irishiranian is offline irishiranian  United Kingdom
diyAudio Member
 
Join Date: Mar 2010
Hiya. Thanks for your help. I double checked the old resistor and it's definitely 10 ohms /5w. I've changed it with a 10w but as I understand it that shouldn't make a difference if the R is the same.

I'm intrigued to see how the 10ohm affects the presence of the midrange so will try a couple of different values. I have a 9 ohm and then some 3s. I presume I can put a couple together in series and just add their respective values?

Will report back!

Thanks all.
  Reply With Quote
Old 24th February 2017, 10:57 AM   #18
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Location: Portsmouth UK
The main event on midrange presence is actually the 12uF capacitor.

Click the image to open in full size.

I just roughly simmed it with a deteriorated bass shunt electrolytic @ say, 4uF. And a 3.9uF electrolytic which we assume has a ESR of 1 ohm. The dotted line.

Once you "upgrade" to polypropylene, you lose a bit of midrange presence with the new 12uF and the tweeter is about 1dB louder. But that may mostly because the original bass shunt capacitor had wandered out of spec, not because it's bad. These are smallish differences.

TBH, I'm winging it a bit on the bass, because I'm using 8 ohm drivers, but the general idea applies. The bass shunt is a very mild but familiar form of impedance correction and added voicecoil damping which I use myself. It doesn't do an awful lot, but tidies everything up around 3kHz, and you can hear the improvement. Troels does something like it here:
CA18RLY/22TAF-G
Attached Images
File Type: png TDL Studio 3 Upgraded Capacitors.PNG (27.0 KB, 28 views)
File Type: png Troels CA18RLY 22 TAF-G speaker.PNG (10.6 KB, 41 views)
__________________
Best Regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 26th October 2017, 10:10 AM   #19
irishiranian is offline irishiranian  United Kingdom
diyAudio Member
 
Join Date: Mar 2010
Good morning. I'm picking up this thread from quite a while ago! Hope you are all well.
I have a couple of questions.

I have just replaced the metal dome tdl tweeter with this soft dome.

AUDAX TW025A0 8 ohm 12 x 8 Tweeter, replaces IMF, Celef, Radford

I like the difference so far but I've had to put quite a big resistor after the cap that's feeding it.

Original value for the metal dome was 2.2. The new one is 10 ohm. It feels like it is at the right db now and was very overbearing with lesser values.

Onto my question!

Should I adjust any other xover components now that I have added such a change in resistance (in series)?

And will such a difference to the original value put a strain on the amp/ resistor/ anything else? (I have a fairly powerful amp. 2 rotel rb981s run as monoblocks -360 w per channel)

(System 7...I bought all of the components for the crossover redesign you kindly did. Haven't put them in yet...will I need to change any of their values now I have this new tweeter? I suspect so. Probably should have tried it before the new tweeter went in!! At least I still have the old ones and now have more options to tinker with!!)

Thanks

Last edited by irishiranian; 26th October 2017 at 10:14 AM.
  Reply With Quote
Old 26th October 2017, 07:45 PM   #20
irishiranian is offline irishiranian  United Kingdom
diyAudio Member
 
Join Date: Mar 2010
Quote:
Originally Posted by system7 View Post
The main event on midrange presence is actually the 12uF capacitor.

Click the image to open in full size.

I just roughly simmed it with a deteriorated bass shunt electrolytic @ say, 4uF. And a 3.9uF electrolytic which we assume has a ESR of 1 ohm. The dotted line.

Once you "upgrade" to polypropylene, you lose a bit of midrange presence with the new 12uF and the tweeter is about 1dB louder. But that may mostly because the original bass shunt capacitor had wandered out of spec, not because it's bad. These are smallish differences.

TBH, I'm winging it a bit on the bass, because I'm using 8 ohm drivers, but the general idea applies. The bass shunt is a very mild but familiar form of impedance correction and added voicecoil damping which I use myself. It doesn't do an awful lot, but tidies everything up around 3kHz, and you can hear the improvement. Troels does something like it here:
CA18RLY/22TAF-G
  Reply With Quote

Reply


TDL Studio 3 crossover upgrade is better and yet worse as wellHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
TDL Studio 3 restoration droeftoeter Multi-Way 8 27th November 2017 10:28 AM
TDL Studio 3s irishiranian Multi-Way 3 24th September 2014 04:55 PM
TDL Studio 0.5- help needed! jonstar78 Multi-Way 0 30th December 2012 02:10 PM
TDL Studio 4 crossovers harwoodspark Multi-Way 2 31st March 2009 12:35 AM
TDL Studio 1 Paul Smith Multi-Way 3 22nd January 2005 12:05 PM


New To Site? Need Help?

All times are GMT. The time now is 01:08 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki