Active ZD5s - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 25th February 2008, 09:26 PM   #11
ttan98 is online now ttan98  Australia
diyAudio Member
 
Join Date: Apr 2006
Location: Melb
I am thinking of building ZD5 out of curiousity of comparing the performance of the passive versus active x-over.

valleyman if you have the opportunity to compare the 2 types of x-over I am interested to hear your opinions.
  Reply With Quote
Old 25th February 2008, 11:22 PM   #12
diyAudio Member
 
Join Date: Feb 2008
Well I just put in the order with madisound for the drivers and xo too - should be here in a few days. In around 10 days, my university term finishes and I'll have 24 free hours a day. I'm trying to get all the parts I need before then so I don't have any setbacks. I'll have the panels cut for me so it's just a case of routing the holes, screwing it together and some soldering. I want to get the build over with in a day or 2. Finishing and tweaking will take longer but I want it up and running quickly.

I'm also going to add the buffer that Nuuk recommends as it apparently improves sound dramatically and it wouldn't take much time/effort.

I have a remote volume control on the way from altronics in australia so that is taken care of.

Once I have them built, which will hopefully then be a couple of weeks, I will probably try out elliott's active xo and will certainly report back on my findings.


With regards to the heatsinks... I definitely don't want them stuck to the outside of the cabinet. I plan on finishing it in gloss black so the outside will be completely smooth. I may just put some very large heatsinks on the chips in the compartment and keep a close eye on the temperature to begin with.
  Reply With Quote
Old 26th February 2008, 03:09 AM   #13
ttan98 is online now ttan98  Australia
diyAudio Member
 
Join Date: Apr 2006
Location: Melb
valleyman,

great .... looking forward towards reading your findings...
  Reply With Quote
Old 26th February 2008, 07:04 AM   #14
zdr is offline zdr  Belgium
diyAudio Member
 
zdr's Avatar
 
Join Date: Nov 2005
Location: Brussels
I have built floorstanding version of ZD5 without sand chamber and reduced depth to keep volume constant. However, there are reports that sealed version works a bit better with mids, so you probably made a good choice. I am thinking of reducing mine to closed, pink noise does show some inconsistencies in the area of 100hz, and I do occasionally experience boomy bass.
  Reply With Quote
Old 26th February 2008, 07:34 AM   #15
ttan98 is online now ttan98  Australia
diyAudio Member
 
Join Date: Apr 2006
Location: Melb
Quote:
Originally posted by zdr
I have built floorstanding version of ZD5 without sand chamber and reduced depth to keep volume constant. However, there are reports that sealed version works a bit better with mids, so you probably made a good choice. I am thinking of reducing mine to closed, pink noise does show some inconsistencies in the area of 100hz, and I do occasionally experience boomy bass.

Before you close the port off, stuff the port with socks and listen for any change.
  Reply With Quote
Old 26th February 2008, 04:58 PM   #16
zdr is offline zdr  Belgium
diyAudio Member
 
zdr's Avatar
 
Join Date: Nov 2005
Location: Brussels
I did already, but bass is still a bit boomy at times. They are close to the corners due to space constraints imposed by my beloved wife, so that does not help either. On the other hand, Hatt MKIII in the same position sounds like it has a hidden sub
  Reply With Quote
Old 26th February 2008, 08:47 PM   #17
diyAudio Member
 
Join Date: Feb 2008
I've been consulting the datasheet with regards to my potential heat issues. With 70V Vcc into 8Ohm the max power dissipation is 35W and the max heatsink thermal resistance suggested is then 2.4oC/W at 25oC ambient.
If I were to really err on the safe side and get a <= 1.5oC/W heatsink and leave the back of the compartment open so air can get in and out that would be sufficient.
Thinking about it I doubt anyone will be able to answer this for me so I suppose I'll probably just have to keep an eye on them for a bit. I could always just get a couple of spare 3886s in case
  Reply With Quote
Old 26th February 2008, 08:52 PM   #18
ttan98 is online now ttan98  Australia
diyAudio Member
 
Join Date: Apr 2006
Location: Melb
Quote:
Originally posted by zdr
I did already, but bass is still a bit boomy at times. They are close to the corners due to space constraints imposed by my beloved wife, so that does not help either. On the other hand, Hatt MKIII in the same position sounds like it has a hidden sub

I believe this speaker is design for open space with 3-4 db BSC, if placed close to wall it may sound boomy.

You may have to change the x-over slightly particularly the inductor on the woofer ie reduce BSC to 1-2 db. Sorry, I am no x-over expert. I don't think JK returns email responds either. Ask Jays on this site, he is a friendly person he may help.

cheers.
  Reply With Quote
Old 26th February 2008, 09:32 PM   #19
gfiandy is offline gfiandy  United Kingdom
diyAudio Member
 
gfiandy's Avatar
 
Join Date: Jul 2003
Location: Cambridge UK
The 3886 has thermal overload protection, the sPike protection, so you shouldn't end up damaging the parts. When this starts activating the sound gets very hard and unpleasant to listen to so if you find this happening at high volumes then you probably need a bigger heat sink or more air flow. Don't keep pushing it under these conditions as eventually it can fail.

Regards,
Andrew
  Reply With Quote
Old 1st March 2008, 03:07 PM   #20
diyAudio Member
 
Join Date: Feb 2008
I have found a solution I'm sure will work well for the heatsink issue.

http://uk.rs-online.com/web/search/s...7-5037&x=0&y=0

This heatsink is very low profile, only 15mm tall so I can easily attach it to the back of the speaker without significantly adding to the depth and it should provide overkill heat dissipation if anything.

I also spoke to a friend of mine who i recently discovered builds sound systems for clubs and he told me he has a 70% trade discount at the builders merchant down the road and can get large sheets of birch ply for under 20 so thats a huge bonus. He also has access to a workshop with laser cutting facilities so I can have the panels laser cut and do all the work in the workshop.

Should be getting on with this in 10 days or so, look forward to posting back with the results
  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
Active 3-ways with solen active loudspeaker module soundemon Multi-Way 14 19th March 2009 11:17 AM
Component Suggestion: 2-way active now, 3-way active later CanadianDream Multi-Way 6 3rd August 2007 04:53 AM
Behringer DCX2496 I want to try active biamping using it as the active xover. georgehifi Digital Line Level 3 15th August 2006 07:46 AM
Active 3 Way vs Active 2.1: Too many alignments and too may questions. goldyrathore Multi-Way 1 22nd April 2005 02:42 PM
XVR1 active crossover, discrete active stage promitheus Pass Labs 18 22nd July 2002 01:29 AM


New To Site? Need Help?

All times are GMT. The time now is 09:01 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