Canuck Audio Mart Hifi and Audio ForumCanuck Audio Mart Hifi and Audio Forum
It is currently Thu Apr 26, 2018 4:56 pm

All times are UTC - 8 hours




Post new topic Reply to topic  [ 32 posts ]  Go to page 1, 2, 3  Next
Author Message
PostPosted: Mon Apr 16, 2018 12:10 pm 
Offline

Joined: Mon Oct 26, 2015 10:53 am
Posts: 5
Location: Guelph, ON, CA
I've been tinkering with an old pair of Leigh speakers i picked up a couple years ago and found them to be a little muddy. The drivers are in good shape thankfully, so I started in on the crossovers. Opening them up revealed a pair of capacitors but no crossover. I replaced the capacitors with some Solen metal/poly and found the was a huge improvement.

Being new to the electronics side of audio, would it be worth building an actual crossover?

Sent from my SM-G955W using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 12:21 pm 
Offline

Joined: Tue Jul 05, 2005 3:09 pm
Posts: 1383
Location: Sherbrooke, QC, CA
Maybe you could provide details concerning the number of drivers in these speakers?

I dunno, but I think a two way speaker that is vintage could have had something entirely minimalist to divide upper from lower frequencies.

Some more technically astute members will probably provide you with more elaborate explanations.

Hope you enjoy your speakers as this hobby is all about fun is it not?


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 12:24 pm 
Offline
User avatar

Joined: Mon Jun 12, 2006 8:20 am
Posts: 4984
Location: London, ON, CA
Those capacitors ARE the crossover. Changing it would change the sound, and you might not like the difference.
There are a number of speaker designs that use a simple capacitor crossover. Leave them as they are.

_________________
1978 Rickenbacker 4001, 2010 Gibson Thunderbird, and Dean Fretless Basses;
1987 Guild Nightbird, 2000 Taylor 310KCE, and Godin 5th Avenue Guitars.

If you can use one of those newfangled Internets, you can post photos in your damn classified ads. :roll:


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 12:25 pm 
Offline

Joined: Thu Aug 03, 2006 4:43 pm
Posts: 663
Location: Ottawa, ON, CA
Arguably, you do have a cross-over, it's just a very simple one (full range on the woofer, first order on the tweeter).
It would be helpful to know the exact model, but at first thought, if they cheaped out on the cross-over, how good are the drivers? Adding a more complex cross-over might help smooth the frequency response... but as you ask, would it be worth it?

Dave


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 12:38 pm 
Offline

Joined: Fri Jun 01, 2012 8:18 pm
Posts: 995
Location: Richmond Hill, ON, CA
If you still have some unwanted resonance (cup your hands around your mouth and speak), you can add some fiberglass insulationto the inside.
Leigh Marsland speakers would not warrant much more.

Cheers,
Alec


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 1:08 pm 
Offline

Joined: Wed Feb 27, 2013 8:43 am
Posts: 1018
Location: Stratford, ON, CA
Hi,

First order cross-overs in a two way speaker only need a single capacitor - so. as others mention above, there is a cross-over just not a very technically complex one. The woofer effectively runs full range and the tweeter's lower end slopes down from the X-over point which is set by the caps value, and I think that slope is around 12 db per octave (corrected to 6 db per octave - see below), so the two drivers actually do i]cross-over[/i].

Some designers think first order is the holy grail (EPOS say) and chose drivers with immense care in order to achieve it and thus get a coherent mid-range. You can assume that level of fanatical care was probably not applied in the case of your pair.

Cheers,
David Neice

_________________
Chinese Proverb: 'Man who waits for roast duck to fly into mouth, waits very, very long time'.


Last edited by buybye88 on Mon Apr 16, 2018 3:38 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 1:55 pm 
Offline

Joined: Mon Jun 01, 2015 4:49 pm
Posts: 381
Location: Coquitlam, BC, CA
As the King of making a silk purse from a sow's ear, I can say you should be content with what you've done. New and/or better caps make all the difference, and while you're doing that some wiring upgrades wouldn't hurt. Then maybe change the dampening material and you might have a vastly improved speaker. Or, like, start with good ones...


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 2:50 pm 
Offline

Joined: Tue Oct 11, 2005 2:12 pm
Posts: 693
Location: Waterdown, ON, CA
buybye88 wrote:
Hi,

First order cross-overs in a two way speaker only need a single capacitor - so. as others mention above, there is a cross-over just not a very technically complex one. The woofer effectively runs full range and the tweeter's lower end slopes down from the X-over point which is set by the caps value, and I think that slope is around 12 db per octave, so the two drivers actually cross-over.

Some designers think first order is the holy grail (EPOS say) and chose drivers with immense care in order to achieve it and thus get a coherent mid-range. You can assume that level of fanatical care was probably not applied in the case of your pair.

Cheers,
David Neice


David. In a first order alignment with a single capacitor on the tweeter the slope would be descending at a 6db per octave.


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 3:26 pm 
Offline

Joined: Tue Jul 05, 2005 3:09 pm
Posts: 1383
Location: Sherbrooke, QC, CA
Quadzilla wrote:
Those capacitors ARE the crossover. Changing it would change the sound, and you might not like the difference.
There are a number of speaker designs that use a simple capacitor crossover. Leave them as they are.



That is what I was alluding to by using the word "minimalist" and I was also going to suggest to leave well enough alone.

I am trying to be nice and polite and still get myself into trouble. :wink:

-- 16 Apr 2018 23:30 --

Well one thing you can be sure is that this crossover was not the brainchild of the late Jim Thiel.


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 3:37 pm 
Offline

Joined: Wed Feb 27, 2013 8:43 am
Posts: 1018
Location: Stratford, ON, CA
Hi,

eclectique wrote: 'In a first order alignment with a single capacitor on the tweeter the slope would be descending at 6 db per octave'.

I wrote wrongly: 'at around 12 db per octave.'

Eclectique is dead right. I stand corrected. 12 db per octave would be second order. Thank god for science and group based knowledge!

Cheers,
David Neice

_________________
Chinese Proverb: 'Man who waits for roast duck to fly into mouth, waits very, very long time'.


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 4:11 pm 
Offline
User avatar

Joined: Sun Aug 15, 2010 11:02 am
Posts: 1176
Location: Brandon, MB, CA
Ignore all previous advice.

Slap in some dilithium crystals and you'll be amazed at the difference! 8)

_________________
"It is the mark of an educated mind to be able to entertain a thought without accepting it." (Aristotle, 384-322 BCE)


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 4:19 pm 
Offline
User avatar

Joined: Mon Jun 12, 2006 8:20 am
Posts: 4984
Location: London, ON, CA
NordicNorm wrote:
Ignore all previous advice.

Slap in some dilithium crystals and you'll be amazed at the difference! 8)


If it's not Scotty, it's CRAP !!!


Attachments:
Scotty.jpg
Scotty.jpg [ 91.16 KiB | Viewed 759 times ]

_________________
1978 Rickenbacker 4001, 2010 Gibson Thunderbird, and Dean Fretless Basses;
1987 Guild Nightbird, 2000 Taylor 310KCE, and Godin 5th Avenue Guitars.

If you can use one of those newfangled Internets, you can post photos in your damn classified ads. :roll:
Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 4:36 pm 
Offline

Joined: Mon Jun 01, 2015 4:49 pm
Posts: 381
Location: Coquitlam, BC, CA
Oh, yes, it could be worth it to build/buy a more sophisticated crossover, sorry.


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 5:11 pm 
Offline

Joined: Tue Oct 11, 2005 2:12 pm
Posts: 693
Location: Waterdown, ON, CA
rustee wrote:
Oh, yes, it could be worth it to build/buy a more sophisticated crossover, sorry.


No Sir. Replacing the old lytics in series with the tweeter is all that's needed.


Top
 Profile  
Reply with quote  
PostPosted: Mon Apr 16, 2018 5:57 pm 
Offline
User avatar

Joined: Mon Jun 12, 2006 8:20 am
Posts: 4984
Location: London, ON, CA
ecclectique wrote:
rustee wrote:
Oh, yes, it could be worth it to build/buy a more sophisticated crossover, sorry.


No Sir. Replacing the old lytics in series with the tweeter is all that's needed.


Yep. There are so many variables to consider when designing a crossover that just dropping a generic one into a speaker is a random exercise, at best. Also, the more complex the crossover design, the more amplifier power it usually requires.

_________________
1978 Rickenbacker 4001, 2010 Gibson Thunderbird, and Dean Fretless Basses;
1987 Guild Nightbird, 2000 Taylor 310KCE, and Godin 5th Avenue Guitars.

If you can use one of those newfangled Internets, you can post photos in your damn classified ads. :roll:


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 32 posts ]  Go to page 1, 2, 3  Next

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group