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 26th December 2012, 12:03 PM   #21
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
That looks pretty close, at first glance. I don't know hornresp well enough to help you.
Of course the best idea is to built it and measure it. Then you will really know what's going on. You could have your active crossover ready to go and just plug in the values you need.

Better yet (IMO) build the passive version to hear if you like it. You may, or may not, want to alter the filter functions of the passive version.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 5th January 2013, 05:32 PM   #22
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
Blog Entries: 1
Okay, I now have acquired the drivers, the wood cuts (in 22mm MDF) and most of the other things I need for the speakers. The drivers are currently breaking in, and will get plenty of hours before being put into the cabinets. I'll also be trying my luck with a router to add chamfered edges to the front baffle and flush mount the drivers.

And I will also get the parts for the (external) passive XO and take my time going active. I'll "design" a 3rd order spread frequency electronic crossover, with an added shelving lowpass for baffle step correction (3dB around 500Hz) in the woofer section, and an allpass in the tweeter section (the latter for time/phase alignment).

I'll keep you posted on my progress, maybe there's something of interest to others to be seen here.
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 7th January 2013, 01:44 PM   #23
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
Blog Entries: 1
Before I go ahead, can someone check my crossover design please?
Like I said, I'm going with the 3rd order Butterworth electronic crossover, low pass at 2.5kHz, high pass at 3.5kHz. I added a 3db baffle step compensation for the woofer at 526Hz (baffle width of 231mm), a 60us time delay for the tweeter, and output buffers with individual level setting potentiometers (Bourns 3386). A DCB1 will act as the input buffer to drive the 1st order low/high pass from a low impedance source.

About the all pass for time alignment of the tweeter: When the drivers are mounted, the woofer's voice coil is approximately 45mm behind the tweeter's, which would translate to about 130us delay. Since the high and low pass are 90 out of phase, then with the right polarity the tweeter will be lambda(3.5kHz)/4=24.5mm~71us behind, which leaves just around 60us for the all pass. Correct?

Do the resistor values look okay in general?
Would you change the level setting and output buffer circuitry? Maybe to a variable gain stage? Or would using the output buffer to drive a lower impedance pot (moving the pot from buffer input to buffer output) result in lower noise?
Attached Images
File Type: jpg xover_full.jpg (42.6 KB, 108 views)
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 7th January 2013, 11:19 PM   #24
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
Blog Entries: 1
Here's a revised version of the crossover.

I made a mistake in calculating the baffle step frequency in my initial design. I made some corrections and calculated the new resistor values according to Baffle Step II.

I'd like to ditch the conventional DC coupled level controls and directly drive a 2k linear potentiometer in series with a 3k resistor with the last stage of the filter. The woofer amp is DC coupled at the input and there will be a large cap (>20uF) in series with the tweeter, so I don't think there is any need for additional DC blocking caps.

Would anything advise against building the circuit on a double sided prototype board (Roth RE321-LF) with a copper ground plane on top?
Attached Images
File Type: jpg xover_dc.jpg (51.5 KB, 82 views)
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 12th January 2013, 09:31 PM   #25
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
Blog Entries: 1
It has begun...



(oh, and the woofer amp is AC coupled at the input...)
Attached Images
File Type: jpg IMG_20130112_170841.jpg (422.4 KB, 73 views)
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 13th January 2013, 03:47 AM   #26
Zoodle is offline Zoodle  Australia
diyAudio Member
 
Join Date: Jun 2009
When/if you want to convert to active, consider the ESP P09 pcb. Excellent, IMHO.
  Reply With Quote
Old 21st January 2013, 09:08 PM   #27
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
Blog Entries: 1
I managed to finish the speakers last weekend, and they are already hooked up to my "new" system.

For now I settled for a 2nd order PLLXO that is being driven by my trusty old BOZ. Since the BOZ has a 5k lin pots at the output, I connected the insertion loss-ridden LP on top of the pot, and the HP via the wiper. This gives a nice level control for high and low frequencies. Global volume is managed via a 25k log pot at the pre's input (R107 100k resistor to ground removed). I've added a schematic. I could also start a new thread on the BOZ PLLXO if someone is interested and go into detail there.

The LP@2400Hz is then fed into a LM4780 stereo amp which has an input impedance of 15k, so with the 10n and 1n caps I had on hands I was left with 6k6 and 66k resistors for the passive XO.
The HP@3500Hz is fed into my lovely Mini Aleph which has an input impedance of approximately 23k1. This input resistance is being used as the second resistor of the passive XO, so with 10n and 2n cap I only needed an additional 5k7 resistor to complete the filter. For details and a nice spreadsheet see TLS.org | Passive Line-Level Crossover

I'm now tinkering with the HP/LP level matching. Any hints on that? I was using pink noise and the real time audio analyzer app of my smartphone to get an idea, and will not see how it matches with what I hear.
The bi-amped system sounds incredibly good so far, crystal clear, fast and punchy. Totally worth the time and effort methinks.
I wonder how big an improvement 3rd order slopes (active), baffle step compensation and proper time alignment could bring additionally...
Attached Images
File Type: jpg BOZ_PLLXO.jpg (41.3 KB, 51 views)
File Type: jpg IMG_20130121_192044.jpg (479.0 KB, 49 views)
File Type: jpg IMG_20130121_192410.jpg (413.7 KB, 19 views)
File Type: jpg IMG_20130121_191331.jpg (445.3 KB, 21 views)
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 23rd January 2013, 02:57 PM   #28
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
Blog Entries: 1
Hm, something just occurred to me: Couldn't I just add a 1st order crossover at the speakers to approximate a 3rd order filter function in total? An inductance (~0.4mH) in series with the woofer, and a smaller cap (~7.5uF, currently 23uF) in series with the tweeter for example. Combined with the 2nd order PLLXO it should have a character closer to 3rd order, no?
__________________
Gravity - Making the G since 13.7 billion B.C.
  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
Basic questions on passive line-level XOs and with bi-amping NebuK Analog Line Level 16 15th December 2011 02:27 PM
Bi amping required active crossovers? xecluded Multi-Way 4 28th April 2011 02:53 PM
A couple of questions re: bi/tri amping, electronic crossovers EmergencyDpt Multi-Way 17 21st December 2008 09:18 PM
SI monoblock/bi-amping questions Reno Class D 1 7th May 2005 12:53 AM
bi-amping through passive crossovers ultrachrome Multi-Way 4 31st March 2005 01:14 AM


New To Site? Need Help?

All times are GMT. The time now is 11:04 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