And Now For Something REALLY BIG - Page 40 - 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 15th October 2012, 09:22 PM   #391
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
NOtice how differently the Tad performs on different horns.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 18th October 2012, 08:06 AM   #392
diyAudio Member
 
theophile's Avatar
 
Join Date: Sep 2006
Location: Sunshine Coast Queensland Australia
Quote:
Originally Posted by ScottG View Post
But it IS!

JBL 4355 speakers restored by Kenrick Sound has been delivered to Mr. Abe's room - YouTube

Ok.. not really, but it's not exactly large either.


..I don't know Japanese (at all), but I suspect the movers (just before unwrapping the 1st one) were saying something along the lines of:

"you want us to put this where?"
Interesting YouTube clip.

One turntable is the Yamaha GT 2000. I think that the other possibly might be the Yamaha GT 2000x.
  Reply With Quote
Old 20th October 2012, 09:21 AM   #393
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
Interesting Q from Ed & answer from jzagaja about the pros/cons of E-JMLC 600 and Iwata 600 (from this thread Waveguides and horns)

Quote:
Originally Posted by Ed LaFontaine View Post
A system I am working on would benefit from some input......My project will be a "poor man's" effort and favor an elliptical format for the horn. I want a smaller form factor for the horn. My crossover point will be determined. I would like any input for the relative merits to choose between the E-JMLC 600....or the Iwata 600
Quote:
Originally Posted by jzagaja View Post
Ejmlc has twice as wide HF dispersion. Use it with DE500 or similar. Disadvantage? Carefully measure power reponse and equalize otherwise at some angles and higher loudnesses you can hear some midrange tonal abberrations. Much like waveguides. Iwata is easier to work with.
What thinks you?
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 20th October 2012, 06:03 PM   #394
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
From what I've heard others say, that pretty much sums it up.
  Reply With Quote
Old 20th October 2012, 11:12 PM   #395
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
ok, so I think I'm left with the Iwata-600 and maybe the JMLC-400. Iwata doing well until dying dramatically some time before 20khz. JMLC looks to have controlled dispersion but with a drop out after 10khz (eq fixable?) but continues past 20khz all be it at reduced levels.


__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 20th October 2012, 11:33 PM   #396
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Im gonna buy the jmlc400 ot tractrix 350, and diy a wood iwata. Got some jbl 2446 15". Now looking to get the horns.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 21st October 2012, 08:09 AM   #397
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
Hey hey! buzzforb is first to a decision!! Similar responses for the tractrix & JMLC. A penny for your reasons behind these choices (circular horns over Iwata etc)?

The response graphs show the Tractrix to be smoother but there is the same sort of droop (as the JMLC) of -10.0 from its peak at 2khz to 20khz. Of course this set of response measurements are made with different drivers - BMS - not the Faital Pro we are looking at. And as I learned earlier, dispersion is a physical characteristic of the horn and cant be changed, response can be

I assume (insert appropriate saying) the JMLC-400 would have a similar polar response to the JMLC-350 as no polar measurement is given for the 400? TBH the Iwata looks to have the better response, but the big kid in me loves the idea of a 48cm diameter horn in the livingroom!! (When people ask if we have kids I answer, 'yes me')

ooo ooo another question!!!! do you align the CD diaphragm/voice coil with the bass drivers voice coil OR the horn end with the cone?
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 21st October 2012, 10:04 AM   #398
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Hi guys

I would suggest the JMLC horns. Have a look at Lynn Olson's comments in the 'Beyond the Ariel' thread. Here are some of his comments.

Quote:
Originally Posted by Lynn Olson View Post
Here's one of Bjorn Kolbrek's simulations comparing the power factor of a T=0.707 LeCleac'h horn that is exit-angle-matched to the Altec 288 (8 degrees) compared to a conical horn. (Both horns are simulated in free air, not mounted in a cabinet.)

The thin black trace shows the resistance term seen by the 288 driver with the LeCleac'h horn, and the thin red trace shows the reactance (or reflection) of the LeCleac'h horn. Like an antenna at RF frequencies, the goal is to get signal out of the antenna and radiated into free space, not reflected back to the transmitter. For an RF system, the wasted power heats up the power tube and could potentially damage it, and for an audio system, the reflected power bounces off the diaphragm and phase plug and re-emerges 2 milliseconds or so later.

Reflections in horns are quite undesirable, since they result in significant reflections in the time domain. Since they are reflections and not resonances, conventional frequency-domain equalization does not improve the time-domain response - it makes it worse.

The heavy black trace shows the resistance term seen by the 288 driver with a conical horn, and the heavy red trace shows the reactance (or reflection) of a conical horn. (The simulated conical uses a smoothed Quadratic Throat transition region between the compression driver and the horn expansion.)

Note much poorer diaphragm loading in the critical 1 to 5 kHz region, despite the conical being the same size as the LeCleac'h horn. More significantly, the reflections are much stronger as well. The LeCleac'h has reflected energy down to 10% at 700 Hz, while the conical only drops into the 10~20% region at frequencies above 5 kHz. The "lower efficiency" of the conical in the 1 to 5 kHz region is actually energy bouncing around in the horn. Sure, you can solve the energy-loss problem with more input power, but what does that do for all that reflected energy bouncing around inside?

Why am I not a fan of conical and near-conical horns? This is why. The combination of Newell and Holland's direct measurements (shown in previous posts) combined with Bjorn's simulations, showed the problems with uniform diaphragm loading are quite severe, and not responsive to equalization. Yes, the gross FR aberrations can be corrected with notch filters, and/or active EQ. But that has no effect on a reflection series, and coloration in the 1 to 5 kHz range is the worst possible spectral place for problems to happen in a loudspeaker. If you've wondered why commercial constant-directivity loudspeakers used in PA systems and theaters have an unpleasant fatiguing quality in the midrange, this is the reason.
These comments are from post #8108. These is plenty more comments is the previous pages. Have a look. So my vote is for the JMLC.

Enjoy,
Deon
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 21st October 2012, 11:12 AM   #399
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
FWIW, i am getting different 15" driverd. Two veryreliable sources tell me that despite their reputation for quality, the 2226 are not best idea for home based hifi, because they liked to br pushed to really open up. At 97dB efficiency, we cant push anything, in a home, or our ears will bleed. I will be choosing between Altec 515, 416, TD15M, or some older JBL, like e130,e140, me15a. These are rated for less power, tend to hav elighter diaghrams, big VAS, and low Le. I tmeans they will nee dbig boxes to go low, but should have good transient attack and clarity in midbass, which most people are talking about when they talk about bass.

For the horns, i am choosing Iwata, becaus ei can diy one failry easily and will basically amount to cost of wood and time. Jmlc vs tractric is just a decision. Kohlbreck, the guy who measured the jmlc for lynn, is now listening to another horn. That tells me that the jmlc is not the undisputed end of th eline. Also, i fyou look at the ETF article i linked, while the JMLC and Kulwegen horns measured well, they were not chosen first in terms of sound. Go figure.

Fo rth ecompression driver, i am looking at the 288 or jbl2440/1. These are fairly well regardedand can b eha dfor similar price as larger Faital. I know lots of fplks immediately go fo flatresponse, claimin gthis is how it should be done, but time has proven over and over, that the theory is just that, theory. Our brains are not computers and they hear things differently. Whil ei belive it is very importan tto try to understand what we are hearing, i dont believe in shapon gwhat i hear, by what i see on a graph. I have enjoyed Lynns thread, mainly because he tweaks based on listening and soun dover measuremwnts. There are many newer compression drivers that will measure far superioir to th e288, an dsom epeople like them, bu tjust as many like the 288. Truth is, we won tknow till we try.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 21st October 2012, 11:38 AM   #400
diyAudio Member
 
Join Date: Nov 2009
Location: Birmingham, UK
Quote:
Originally Posted by JRKO View Post
ooo ooo another question!!!! do you align the CD diaphragm/voice coil with the bass drivers voice coil OR the horn end with the cone?
Align the coils.
  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
Transformers: How big is TO big?? dfdye Power Supplies 39 4th September 2010 02:30 PM
Big Toroids & Big Caps K-amps Swap Meet 10 25th June 2009 07:43 PM
Having problems with port size... how big is far too big? fjhuerta Multi-Way 10 30th August 2005 06:20 PM
Big Big hum ??? vlljpior Tubes / Valves 4 26th August 2005 03:53 AM


New To Site? Need Help?

All times are GMT. The time now is 03:39 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