Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Suitable midrange cone, for bandpass mid in Unity horn.
Suitable midrange cone, for bandpass mid in Unity horn.
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 9th April 2013, 04:11 PM   #701
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by Hrmmf View Post
1. Since the geometry of the Beyma faceplate allows me to place the midrange, thus the mid-holes very close to the throat, why not just use one 2 compression driver >500Hz. Are compression mid-drivers just plain no-no? (I have a pair of Community M200 + JBL 2482 on layaway)
2. Why not use a pair of large, say 3 dome midranges, is this related to dome geometry?
3. Is the Beyma a bad choice altogether, Synergy-wise?
Thomas,
1. A single compression driver in an offset mounting will not "illuminate" the horn area, dispersion will not be uniform.
The distance from the 2482 diaphragm to the exit is around 90mm, the HF would need to be delayed to compensate for the added path length of the mid driver.
A 2482 would still need another pair of drivers between it and the LF.
2.The contained volume between the cone and the exit port makes an acoustic low pass filter, domes would make for a more difficult construction.
Most domes have little excursion, so output would be less than cones typically used for midrange in a Synergy horn.
3.Considering a compression driver would load better, have greater sensitivity, and cost less, one could say that the Beyma TPL-150 AMT is not a good choice.
Tape together a cardboard horn of the desired dispersion pattern and see how well (or poorly) the TPL-150 does in it.
If it does well, consider using a pair of 6.5" cones for the mids, then all you would need to complete the system would be sub woofers, which could be in separate cabinets.

Art
  Reply With Quote
Old 9th April 2013, 04:19 PM   #702
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by rvrazvan View Post
12 hf drivers in one horn. that's a wow!
In the horn pictured below, there is one HF driver at the horn throat, four mid cones with two exit holes for each, and two low cones, also with a pair of exit holes.

Tom Danley's layered combiner does allow for multiple HF drivers on a single horn, but multiple HF drivers are not generally required for home use other than for persons with severe hearing impairment .

Art
Attached Images
File Type: png Six drivers.png (33.9 KB, 575 views)
  Reply With Quote
Old 9th April 2013, 04:38 PM   #703
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by Patrick Bateman View Post
Come to think of it, another interesting option might be to simply subdivide a Unity horn into four horns. For instance, instead of using a Unity horn that measures 50 degrees by 50 degrees, one might use *four* Unity horns that are each 25 degrees by 25 degrees.
Patrick,

Your "simple" option would require four times the cabinet work, and four times the drivers as a normal Synergy horn uses for the same coverage.

In addition to that complexity and expense, to avoid comb filtering the four horns need to be angled away from each other in both the vertical and horizontal planes, requiring some rather "interesting" filler pieces between the mouths.

And though if done perfectly, four conical horns can provide fairly "seamless" coverage, believe me (I have tried it) a single conical horn of the same coverage angle will have more even coverage.

Art
  Reply With Quote
Old 9th April 2013, 06:38 PM   #704
Hrmmf is offline Hrmmf  Denmark
diyAudio Member
 
Join Date: Dec 2008
Location: Bramming
Thank you, Art.

Quote:
Originally Posted by weltersys View Post
Thomas,
1. A single compression driver in an offset mounting will not "illuminate" the horn area, dispersion will not be uniform.
The distance from the 2482 diaphragm to the exit is around 90mm, the HF would need to be delayed to compensate for the added path length of the mid driver.
A 2482 would still need another pair of drivers between it and the LF.
What a shame, I kinda liked the idea of compression mids. It should be noted that I intend to do a 3-way Synergy, I'm just starting from the top!

Quote:
Originally Posted by weltersys View Post
2.The contained volume between the cone and the exit port makes an acoustic low pass filter, domes would make for a more difficult construction.
Most domes have little excursion, so output would be less than cones typically used for midrange in a Synergy horn.
Hmm, that eliminates the use of domes...

Quote:
Originally Posted by weltersys View Post
3.Considering a compression driver would load better, have greater sensitivity, and cost less, one could say that the Beyma TPL-150 AMT is not a good choice.
Tape together a cardboard horn of the desired dispersion pattern and see how well (or poorly) the TPL-150 does in it.
If it does well, consider using a pair of 6.5" cones for the mids, then all you would need to complete the system would be sub woofers, which could be in separate cabinets.
I already have a pair of TPL's so price is somewhat unimportant. Having build a pair of 7Pi cornerhorns with the well regarded B&C DE250 compression driver I must say that the Beyma is just in another league. I have owned several pairs of speakers which employs compression driver tweeters, and they're just not of my taste. They fail in the naturalness and resolution department compared to the AMT.

I've modelled with the closed back Eminence LA6-CBMR, and it looks good. My only concern is that the model show best performance with very small holes (~2x10mm = ~2x4cm^2). I'm worried that it will sound squeezed when forcing
133cm^2 through the small band-pass holes?

/Thomas

Last edited by Hrmmf; 9th April 2013 at 07:02 PM. Reason: spelling
  Reply With Quote
Old 9th April 2013, 11:46 PM   #705
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by Hrmmf View Post
Thank you, Art.
What a shame, I kinda liked the idea of compression mids. It should be noted that I intend to do a 3-way Synergy, I'm just starting from the top!

I've modelled with the closed back Eminence LA6-CBMR, and it looks good. My only concern is that the model show best performance with very small holes (~2x10mm = ~2x4cm^2). I'm worried that it will sound squeezed when forcing
133cm^2 through the small band-pass holes?
Thomas,

Cone drivers on an offset horn are "compression drivers" though they don't usually have as high of a compression ratio as most HF compression drivers (less "squeezing"). You are proposing a compression ratio of 16/1 (higher than most HF compression drivers) for the LA6-CBMR, at high power levels that would probably break the cone.

I am using Eminence Alpha 8" and 6" with relatively small (less than a 5/1 compression ratio) exit holes, they sound and measure well.

I'm not sure what a "squeezed" sound would look or measure like though...

Art
Attached Images
File Type: png Alpha 8 cutout.png (46.6 KB, 559 views)
  Reply With Quote
Old 10th April 2013, 12:17 AM   #706
Patrick Bateman is offline Patrick Bateman  United States
diyAudio Member
 
Patrick Bateman's Avatar
 
Join Date: Oct 2006
Location: San Diego
Are you sure?

Off the top of my head, here's the cost of a couple of options.
The first option is the 'traditional' one; it uses a three way Unity horn to cover nine octaves:

Click the image to open in full size.
Lambda Unity Horn
tweeter : B&C DE25 ($125)
midrange : 4 x Misco JC5RTF-B ($120)
woofer : Lambda something-or-another ($200)
crossover : very complex three way crossover. Minimum $100 per channel
total : $545 per channel, plus a big ol' cabinet

versus
An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.

Yorkville PSA1
tweeter : dual BMS 4550 ($300)
midrange/woofer : 4 x 18 Sound 6ND430 ($600)
crossover : relatively simple two-way DSP xover. $100 per channel.
Total : $1000

Admittedly, the Paraline option is more expensive. By almost a hundred percent.
But it's also simpler for the DIY'er, and it's smaller.
I have a PILE of Unity horns in the garage that just didn't work.
I'm not 100% sure that my idea will work, but if I'm correct, it seems that we can reduce the complexity of a Untiy horn from a three-way to a two-way, and I think that will be a lot easier to get right. The passive xover in a Unity horn is fairly hideous to get right.

I think the easiest way to reduce the cost of the second option is to use a midrange with much lower power handling. The main reason the 18Sound midranges cost $150 a pop is that they handle very high power. (I wonder if Yorkville has their own version of the 6ND430? I noticed that their speaker is rated for lower power than the driver that's for sale at ussspeaker.com (Eighteen Sound Speakers - 18 Sound speakers - Eighteen Sound speaker partss - 18 Sound woofers, 18 Sound high frequency drivers and 18 Sound lightweight neodymium low frequency woofers and midrange speakers available here. 18 Sound speaker components))
  Reply With Quote
Old 10th April 2013, 11:35 AM   #707
Hrmmf is offline Hrmmf  Denmark
diyAudio Member
 
Join Date: Dec 2008
Location: Bramming
Thanks Art!

Quote:
Originally Posted by weltersys View Post
Thomas,

Cone drivers on an offset horn are "compression drivers."
Obviously

Quote:
Originally Posted by weltersys View Post
I am using Eminence Alpha 8" and 6" with relatively small (less than a 5/1 compression ratio) exit holes, they sound and measure well.
Maybe I'm doing it wrong, with 5/1 ratio my sims look like (see pics). The larger entry hole/s also gives me a spike at ~3000Hz.
Attached Images
File Type: png Eminence LA6CBMR 5-1 ratio (SPL).PNG (58.7 KB, 485 views)
File Type: png Eminence LA6CBMR 5-1 ratio.PNG (82.1 KB, 474 views)
  Reply With Quote
Old 10th April 2013, 03:32 PM   #708
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Originally Posted by weltersys
Patrick,

Your "simple" option would require four times the cabinet work, and four times the drivers as a normal Synergy horn uses for the same coverage.

In addition to that complexity and expense, to avoid comb filtering the four horns need to be angled away from each other in both the vertical and horizontal planes, requiring some rather "interesting" filler pieces between the mouths.

And though if done perfectly, four conical horns can provide fairly "seamless" coverage, believe me (I have tried it) a single conical horn of the same coverage angle will have more even coverage.

Art
Quote:
Originally Posted by Patrick Bateman View Post
Are you sure?
Yes, I'm sure. I converted my PA from multiple narrow conical horns to 90 degree horizontal conical horns, the coverage is far more smooth now.

Having built both types, I am also quite sure that a simple square or rectangular conical horn is far simpler to build, takes up about an inch less depth and has much smoother frequency response, and more extended HF than a Paraline.

I am also sure that most any single 1" exit driver with diaphragms in the 1.5 to 1.75 inch diameter range is more than capable of clean response down to the point where they are fully usable with a pair of 6.5" or even 8" cones for home use level on a horn with an exit size of around 2 x 2 foot.

Using two cones and a 1" compression driver, driver costs for the above 100 Hz range could be less than $200, with sub woofers added per taste.

Art
  Reply With Quote
Old 10th April 2013, 04:13 PM   #709
weltersys is offline weltersys  United States
diyAudio Member
 
weltersys's Avatar
 
Join Date: Jan 2008
Location: Florida
Quote:
Originally Posted by Hrmmf View Post
Maybe I'm doing it wrong, with 5/1 ratio my sims look like (see pics). The larger entry hole/s also gives me a spike at ~3000Hz.
Hornresp exaggerates the peaks and dips, the spike at 3K may hardly be audible or measurable.
Hornresp also does not take cone breakup into account, the upper response may not follow the sim all that well.
Hornresp will get you in the ballpark, as you can see from your sim, a crossover in the 1000 to 1500 range will work OK.

Last edited by weltersys; 10th April 2013 at 04:17 PM.
  Reply With Quote
Old 10th April 2013, 05:12 PM   #710
bwaslo is offline bwaslo  United States
Old guy with soldering iron
diyAudio Member
 
bwaslo's Avatar
 
Join Date: May 2006
Location: Portland, Oregon!
Suitable midrange cone, for bandpass mid in Unity horn.
the spike looks like the ports aren't close enough to the throat to cover that high.
  Reply With Quote

Reply


Suitable midrange cone, for bandpass mid in Unity horn.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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bandpass Woofer/Midrange? m@ Multi-Way 5 25th March 2006 02:10 AM
looking for 6.5inch woofers suitable for a 30 - 35Hz horn... and a small horn too :P SkinnyBoy Multi-Way 24 13th February 2004 05:06 AM


New To Site? Need Help?

All times are GMT. The time now is 07:08 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki