celestion 66 needs Mid-range - Page 43 - 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 6th March 2010, 05:12 PM   #421
diyAudio Member
 
Join Date: Apr 2006
Location: Midlands
Default use as follows:-

Quote:
Originally Posted by dloper View Post
Hello again Alan - got my Solen poly caps from Falcon, measured as follows: 70.1, 70.34, 70.43 and 70.7 uF. They are BIG - 65mm long and 50mm diameter, but they'll fit my boards ok.

Also added some more soft furnishings to the room, and can reduce the mid attenution quite a lot now. Won't post figures until I've experimented again after fitting the new bass caps.

Stuart
Hello Stuart,

If you want to get as close as possible to a matched pair of 66s in the low midrange measure the DC resistance of both woofers, then:-

With the lower resistance woofer put the 70.34uF as the cap at the output of the filter, and the 70.7uF as the cap in between the inductors.

With the higher resistance woofer put the 70.1uF cap in the output position and the 70.43uF in the between inductors position.

Yes, with such small uF differences this is being a bit obsessive, but I do that, and you may hear the benefit ... hopefully the woofers will have similarly small differences in ohms.

Listen for several sessions, then post your impressions of whatever changes these caps have made to the sound, and then the two resistance measurements within each L-pad.
__________________
Alan

Last edited by alan-1-b; 6th March 2010 at 05:13 PM. Reason: to add a phrase
  Reply With Quote
Old 22nd April 2010, 03:54 PM   #422
diyAudio Member
 
Join Date: Apr 2010
Default ESR Resistor Locations?

This is truly an informative post, I’ve spent the last few days reading through its entirety. Being totally new to all this, it has been quite the task trying to grasp all the information being posted.
My Celestions were purchased new by me in 1980 or so and have been a great sounding speaker in my view over the years. Although, as of late they seem to be lacking and given their age, are probably in need of a refurbish/update to the crossovers. All drivers appear to be OK and in good working order.
My crossovers are the PCB versions, so my plan to update is as follows…

Replace caps with Solen 250v PA series as outlined…
C1, C2 = 6.2uF
C3, C4 = 3.9uF
C5 = 3.9uF
C6 = 2*36uF for 72uF
C7 = 24uF
C8 = 2*36uF for 72uF
May consider a 68uF @ C6 and 75uF @ C8 ??

ESR Resistors, Mills MRA-5 as outlined…
C1, C2 – 6.2uF = 0.5R
C5 – 3.9uF = 3.3R
C6 – 72uF = 1.5R
C7 – 24uF = 1.5R
C8 – 72uF = 1.0R

What I do not totally understand and has me puzzled, is how and where to physically place the ESR resistors, given the compactness of the PCB crossover layout.
Eg. For the 2*36uF caps at C8, I need to raise them above the 2 inductors, using the caps legs to support themselves. So how should the 1.0R be placed; as part of the leg supporting the caps and will it be stout enough to support the caps over the inductors?
As I stated, I’m new to all of this, so any help, explanation would be greatly appreciated. If anyone with the PCB version crossovers, has some pics they could post of their updated crossovers, that would be awesome.

Thanks, Dave
  Reply With Quote
Old 3rd May 2010, 06:14 PM   #423
diyAudio Member
 
Join Date: Apr 2010
Default Seas Tweeter

Quote:
Originally Posted by alan-1-b View Post
Continuing from my Post # 409:-

The SEAS tweeter I listed also in a couple of posts will be better sound than the HF2000 and the Coles, and what I recommend to use at reasonable price - and that is better value than buying old HF2000s from ebay sellers !

The SEAS will require a parallel connected resistor to match its Impedance to the crossover, and a slightly larger capacitance for the output cap of the treble filter in the crossover instead of the 6uF or 6.2uf in the originals.
6.8uF may be sufficient, but I would listen first with 8.2uF.
I will explain the reason for the larger capacitance if anyone decides on this option.
.
Alan, don't know if you're still watching this thread, it's been awhile since any activity, but I'll ask anyhow.

I'm considering replacing my HF2000 tweeters with the Seas H0737 19TFF1 tweeters, could you explain the reason for the cap change?
Also, what resistors would you recommend?

My 66s are the PCB versions.

Thanks Dave

Last edited by damaltor; 3rd May 2010 at 06:35 PM.
  Reply With Quote
Old 6th May 2010, 11:58 PM   #424
diyAudio Member
 
Join Date: Feb 2009
Location: Alberta
Default Md500

Quote:
Originally Posted by alan-1-b View Post
Doug,

the best option would be to buy a pair of as-new MD500 domes from tonedef2, and keep your OK sounding MD500 as a spare.

MF500 seems to have a different Impedance characteristic at its low frequency end than MD500, and is not as cleverly controlled in design.
This will be part of the reason for its lower power handling, as well as the heat capacity of its voice-coil.

If the MF500s are in good condition they can be got to work, and better with another resistor added to the crossover, but I would use MD500.
Consider the price you are asked for a pair of MD500.
Don't pay a lot for MF500 - they are old and condition and life expectancy is not known.
Picked up 2 used MD500's today. A 2 hr drive one way, vs shipping. Left my low vol 500 with the person I bought the *good* ones from. He has a friend who is a Tannoy *expert* ,who he might get to have a look at. Both 66's are singing again!!!! Been so long without that second mid, when it fired up I was almost sscared! Sounding good after 3 hrs of music coming from star choice. (blues channel)
  Reply With Quote
Old 7th May 2010, 12:07 AM   #425
diyAudio Member
 
Join Date: Feb 2009
Location: Alberta
Quote:
Originally Posted by damaltor View Post
This is truly an informative post, I’ve spent the last few days reading through its entirety. Being totally new to all this, it has been quite the task trying to grasp all the information being posted.
My Celestions were purchased new by me in 1980 or so and have been a great sounding speaker in my view over the years. Although, as of late they seem to be lacking and given their age, are probably in need of a refurbish/update to the crossovers. All drivers appear to be OK and in good working order.
My crossovers are the PCB versions, so my plan to update is as follows…

Replace caps with Solen 250v PA series as outlined…
C1, C2 = 6.2uF
C3, C4 = 3.9uF
C5 = 3.9uF
C6 = 2*36uF for 72uF
C7 = 24uF
C8 = 2*36uF for 72uF
May consider a 68uF @ C6 and 75uF @ C8 ??

ESR Resistors, Mills MRA-5 as outlined…
C1, C2 – 6.2uF = 0.5R
C5 – 3.9uF = 3.3R
C6 – 72uF = 1.5R
C7 – 24uF = 1.5R
C8 – 72uF = 1.0R

What I do not totally understand and has me puzzled, is how and where to physically place the ESR resistors, given the compactness of the PCB crossover layout.
Eg. For the 2*36uF caps at C8, I need to raise them above the 2 inductors, using the caps legs to support themselves. So how should the 1.0R be placed; as part of the leg supporting the caps and will it be stout enough to support the caps over the inductors?
As I stated, I’m new to all of this, so any help, explanation would be greatly appreciated. If anyone with the PCB version crossovers, has some pics they could post of their updated crossovers, that would be awesome.

Thanks, Dave

Believe I threw out all the files of the components I used to update my PCB boards, unless they are listed in this forum. I will borrow a digital cam & take some pics of how I mounted everything & post for you as soon as I can. I am an old timer & still shoot pics using film.
  Reply With Quote
Old 7th May 2010, 01:11 AM   #426
diyAudio Member
 
Join Date: Apr 2010
Thanks Moermusic, I'd appreciate that. Pretty sure I know which way I'm going to proceed, but it'll help alot to see others upgrades. These PCB boards are pretty tight.
  Reply With Quote
Old 8th May 2010, 05:32 PM   #427
diyAudio Member
 
Join Date: Apr 2006
Location: Midlands
Default worth the patience !

Quote:
Originally Posted by moermusic View Post
Picked up 2 used MD500's today. A 2 hr drive one way, vs shipping. Left my low vol 500 with the person I bought the *good* ones from. He has a friend who is a Tannoy *expert* ,who he might get to have a look at. Both 66's are singing again!!!! Been so long without that second mid, when it fired up I was almost sscared! Sounding good after 3 hrs of music coming from star choice. (blues channel)
Hi Doug,

I'm very pleased to read that you have a pair of working MD500.
Indeed it is worth the effort required to persevere to get the best result possible.

Post later and tell us what the Tannoy "expert" found in your low output MD500.

************************************************** *********

There is a way to adapt the 66 crossover for the current Morel EM 1308 mid-dome to work
- if readers cannot find working MD500s at reasonable prices -
but that will include spending a bit of time listening and fine-tuning by changing 1 resistor at least, and perhaps 2 resistors ...
I will post about this only if someone asks.
__________________
Alan
  Reply With Quote
Old 8th May 2010, 05:50 PM   #428
diyAudio Member
 
Join Date: Apr 2006
Location: Midlands
Default another Thread to look in

Quote:
Originally Posted by damaltor View Post


What I do not totally understand and has me puzzled, is how and where to physically place the ESR resistors, given the compactness of the PCB crossover layout.

Eg. For the 2*36uF caps at C8, I need to raise them above the 2 inductors, using the caps legs to support themselves. So how should the 1.0R be placed; as part of the leg supporting the caps and will it be stout enough to support the caps over the inductors?
As I stated, I’m new to all of this, so any help, explanation would be greatly appreciated. If anyone with the PCB version crossovers, has some pics they could post of their updated crossovers, that would be awesome.

Thanks, Dave
Hi Dave,

I thought I had posted details somewhere in this thread about the placement and mounting of both the capacitors and the resistors ...
but if such is not here-in, then go to the thread titled:

Crossover nightmare!!!!!!!

started by lorienblack .

It is about Celestion Ditton 44, which has a very similar crossover to 66.

I posted some things in there which may be relevant to other things you are wondering about also.

{There is stuff in there that is irrelevant - I think you will easily identify and be able to evalute or ignore.}

Best is to make new, larger boards to mount the components on, and hardwire everything
- directly connect the components to each other via their own leads, and to a centrally located Ground terminal for the returns to -ive.

There are some photos of large board constuctions in this thread,
but if you want to keep your pcbs, then first look through all the thread again,
because it is very time consuming to type detailed explanations,
and currently I have very little time available for DIY,
but I will look at this thread again in a few days to see what you have found, and what you may need to know next.

For questions that may arise after you read the other thread, post here, not there, if they are 66 related.
__________________
Alan
  Reply With Quote
Old 8th May 2010, 06:00 PM   #429
diyAudio Member
 
Join Date: Feb 2009
Location: Alberta
Default 66's

Alan: If I do find out what he figures, I will for sure let all know.

Now to try & show 2 pics of my finished xovers.

xover 2.jpg

xover 1.jpg
  Reply With Quote
Old 8th May 2010, 06:13 PM   #430
diyAudio Member
 
Join Date: Apr 2006
Location: Midlands
Default Capacitor choices

Quote:
Originally Posted by damaltor View Post

I'm considering replacing my HF2000 tweeters with the Seas H0737 19TFF1 tweeters, could you explain the reason for the cap change?
Also, what resistors would you recommend?

Thanks Dave
Hi again Dave,

basically changing the Capacitance is to allow for the different Impedance of the SEAS to the HF2000 or Coles 4001 in the region of its response where the crossover has to roll off the signal to the tweeter in the same way as Celestion chose so that the tweeter output and mid-dome output will add to flat response, or at least to not cause any peaks or dips in the response that were not in the original.
I will explain more detail when I have time available, if you want to know more about it.

I will post the values for resistors then - 2 for each tweeter - and the cap will have to be larger than 6.2uF ... but for now,
as you are considering changing your tweeters for sonically better, it really is worth using sonically better caps for the tweeter and mids.
The Solen 250 volts are OK for the bass circuit ...
and if dloper posts about listening results with his Solens in there now, we can consider whether to stay with 36 + 36 = 72uF or use 68uF and 75uF.

As you have to buy internationally to obtain Mills MRA-5,
then it is worth buying ClarityCap PX, at least, for the mids and treble,
or Sonicap if the extra price seems OK to you.

If you cannot buy caps Mailorder from USA, then consider the Jantzen Cross Caps available in UK that I posted about in the other thread,
and where there is listener feedback posted ...
but they are larger physical size than ClarityCap.

Given various listener reports, use Jantzen if you want a little more brightness as well as better detail to the sound,
but if you don't want additional brightness, then try to obtain ClarityCap or Sonicap.

Yes, one cannot decide fully about aspects of brightness till after replacing the old caps,
but consider what you are currently hearing, and what you would like to acheive,
and post here so that I know what to recommend worth trying.

***********************************************

Hah, look at what Doug has just posted whilst I was typing !
Thankyou Doug - a picture says a thousand words, and two pictures say ... more !!

The other thread is still worth reading Dave, as it includes matters about Impedance in crossovers ...
and you'll find Doug was there also !
__________________
Alan

Last edited by alan-1-b; 8th May 2010 at 06:20 PM. Reason: to add a paragraph
  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



New To Site? Need Help?

All times are GMT. The time now is 08:29 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