Introducing Helios - 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 26th May 2003, 06:04 AM   #1
Thunau is offline Thunau  United States
diyAudio Member
 
Thunau's Avatar
 
Join Date: Mar 2001
Location: PA USA
Cool Introducing Helios

My latest creation is almost done. I put together a couple of pages showing the speaker and the design. Comments/critique welcome.
Helios Project pages
__________________
"Most people just say what they know, the wise ones know just what to say."
  Reply With Quote
Old 27th May 2003, 08:32 AM   #2
diyAudio Member
 
Join Date: May 2003
Location: Washington State, USA
That looks brilliant, and it sounds like you're very pleased with the sound as well so congratulations!

I'm not experienced in reading polar response charts, but my impression is the dispersion is quite wide and smooth, with only a dip at the upper crossover region - something I wouldn't necessarily expect from the Neo8. Has that been your experience when listening? I've been considering the Neo8 for a project of my own, but have been hesitant because the tight/small sweet spot I usually associate with planar drivers doesn't match very well with my listening habits. I suppose crossing it over to a discrete tweeter helps eliminate any tendency toward beaming, but I'd be very interested in your impression after listening.

Also, any chance you might be willing to share your crossover strategy? It looks like you have your drivers aligned physically, any details you'd be willing to share would be much appreciated!
  Reply With Quote
Old 27th May 2003, 11:00 PM   #3
Thunau is offline Thunau  United States
diyAudio Member
 
Thunau's Avatar
 
Join Date: Mar 2001
Location: PA USA
Quote:
Originally posted by HeatMiser
That looks brilliant, and it sounds like you're very pleased with the sound as well so congratulations!

I'm not experienced in reading polar response charts, but my impression is the dispersion is quite wide and smooth, with only a dip at the upper crossover region - something I wouldn't necessarily expect from the Neo8. Has that been your experience when listening? I've been considering the Neo8 for a project of my own, but have been hesitant because the tight/small sweet spot I usually associate with planar drivers doesn't match very well with my listening habits. I suppose crossing it over to a discrete tweeter helps eliminate any tendency toward beaming, but I'd be very interested in your impression after listening.

Also, any chance you might be willing to share your crossover strategy? It looks like you have your drivers aligned physically, any details you'd be willing to share would be much appreciated!
Thanks. Yes, you are right about the discrete tweeter. It does help with the power response. It helps the speaker sound smoother off axis. The XT25 doesn't start to beam as early as the Neo8, therefore you get a much wider physical area where most frequencies are heard. Plus a small tweeter radiates in a similar pattern to the woofer and midrange drivers.

As to the polar plots. The dip you see in the 5000Hz curve is caused by negative interference between the tweeter and midrange driver. It is normal and is called lobing. The null points to your belly when seated in the sweet spot. You would have to lower your head to notice a suck-out of upper midrange. Other than that, the plot fluctuates mostly in a 10dB window at most frequencies, which makes the speaker sound even and balanced in the room.
The drivers are not aligned perfectly. That is the reason I had to tweak the LP and HP slopes to a non textbook slope. The phase was not tracking right at all with textbook slopes.
I started with textbook 3rd order Bessel acoustic response at 700Hz and 5000Hz for the mid and went from there.
I think I will post this complete design once I'm finished. I'm in the phase of ordering parts for the crossover. Once I solder them and verify that the speaker actually measures (and sounds) the same way as the sim suggests, I'll make it available for download. Keep in mind that:
1. it is an active crossover design
2. Dynaudio drivers are not very easy to come by.
so making it is not going to be very straight forward.
__________________
"Most people just say what they know, the wise ones know just what to say."
  Reply With Quote
Old 28th May 2003, 01:36 AM   #4
diyAudio Member
 
Join Date: May 2003
Location: Washington State, USA
Thunau -

Thanks very much for your additional comments. I realize the speaker you are building is fairly complex, and the Dynaudio is not exactly available from Parts Express , so it's not my intention to try and get enough details from you to copy your design. Rather, I'm interested in your crossover choices as a learning experience - particularly since the mid and tweeter are available at reasonable prices and are generally well-regarded, and you seem to be doing a fine job of matching them to each other.
  Reply With Quote
Old 28th May 2003, 07:55 AM   #5
diyAudio Member
 
Join Date: May 2003
Location: Washington State, USA
Also I re-read my first post and realized I wasn't very clear and may have been misunderstood - it isn't the lobing at the crossover point that I found surprising, it's the overall smoothness of the power response in general. In other words, I'm impressed with the way you've created a speaker with wide, smooth dispersion using the Neo and hope that I can learn some things by following the progress of your project.
  Reply With Quote
Old 28th May 2003, 07:53 PM   #6
Thunau is offline Thunau  United States
diyAudio Member
 
Thunau's Avatar
 
Join Date: Mar 2001
Location: PA USA
Default Neo8 directionality

Neo8, if you look at the polar plots posted by manufacturer, gets progressively more directional from about 7kHz. I use it up to 5kHz with 3rd order LP slope. That assures that the beaming comes mostly at frequencies reproduced by the tweeter, which is what we are all acustomed to. XT25 is not the best at dispersion, there are other tweeters, especially 3/4" models, that disperse high frequencies in much nicer fashion. My choice of that tweeter was dictated more by the low distortion figures and extended frequency response, plus the sound of it is complementary to the planar driver. I have a few tweeters on hand and this one gels with the Neo8 the best.

If you are planning on trying the Neo8, I would say go for it. It's as good a midrange driver as you'll find anywhere. Marry it with a small tweeter at 5000Hz and you got a very nice speaker.
__________________
"Most people just say what they know, the wise ones know just what to say."
  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
Introducing Myself - Greetings! brucedog Introductions 3 30th October 2007 03:59 AM
Helios X5000 Media Server mike_mcf Digital Source 0 27th January 2007 02:50 AM
introducing... lecky Introductions 3 2nd May 2006 09:51 PM
Introducing Myself C.Jackson Introductions 3 19th April 2006 02:47 AM
Just introducing myself. 3beanlimit Introductions 0 5th August 2001 04:23 AM


New To Site? Need Help?

All times are GMT. The time now is 02:58 PM.


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