JBL 2404 and DSP has someone done this? - 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 20th November 2013, 12:27 AM   #1
colofan is offline colofan  United States
diyAudio Member
 
Join Date: May 2008
Location: Loveland, Colorado
Default JBL 2404 and DSP has someone done this?

I have a set of JBL 2404's that i would like to use in a HT setup again. With the newer DSP solutions available now does anyone have pointers on using DSP with the 2404's?
  Reply With Quote
Old 20th November 2013, 04:58 PM   #2
diyAudio Member
 
Join Date: Jan 2008
Colofan,

Pretty wide open question, the desired crossover point, slope, and delay required are dependent on physical location of the tweeter compared to the mid range, and what type of midrange used. The actual response of the tweeter depends on what size baffle it is on, distance to the edges of the baffle, and what is beneath it- a big horn with reflective surfaces, or a cone/dome midrange are quite different.

Assuming your units both match, and match the usual 2404 response (a big ASSumption), applying about a 4 dB boost near 7,000 Hz and 12,000 Hz would flatten the response, since those dips occur in both on and off axis response.
If you were crossing at 24 dB per octave at 4000 Hz or above, the "bump" in response at 1600 Hz probably won't be audible.
Using a 12 dB per octave crossover below 4000 Hz (not generally advisable) would probably benefit from a low Q cut of around 10 dB at 1600 Hz.

DSP varies so much in definitions of "Q", can't tell you what specific value of "Q" and the exact amount of boost or cut would be required to correct the 2404 response.

Art
Attached Images
File Type: png 2404.png (124.1 KB, 207 views)
  Reply With Quote
Old 20th November 2013, 05:24 PM   #3
diyAudio Member
 
speaker dave's Avatar
 
Join Date: Nov 2009
Location: The Mountain, Framingham
Those curves are from a really good one. The ring radiators vary all over the place. The 3 peaks that make up the response can be quite nasty. They did get somewhat better when they trained a lady to go around the perimeter with a ball point pen to crease the edge just inside the suspension point. (I kid you not. You can usually see the blue ink line.)

Anyhow, DSP on the actual measured individual responses should be a significant improvement. I would measure and average across, say +-15 degrees and EQ to that.

David S.
  Reply With Quote
Old 20th November 2013, 05:42 PM   #4
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by speaker dave View Post
The 3 peaks that make up the response can be quite nasty.
David,

Some would use the word "sparkling" rather than "nasty" .

Creasing the suspension edge with a ball point pen without punching through the aluminum is quite a skill !

Art
  Reply With Quote
Old 20th November 2013, 06:42 PM   #5
pos is offline pos  Europe
diyAudio Member
 
pos's Avatar
 
Join Date: Feb 2008
Location: Paris
Quote:
Originally Posted by speaker dave View Post
Those curves are from a really good one. The ring radiators vary all over the place. The 3 peaks that make up the response can be quite nasty. They did get somewhat better when they trained a lady to go around the perimeter with a ball point pen to crease the edge just inside the suspension point. (I kid you not. You can usually see the blue ink line.)
Good first hand info, thank you!
Is it possible to do the same on existing used drivers?
__________________
No loudspeaker system even approaches real life so there is plenty of room for interpretation - Greg Timbers

Last edited by pos; 20th November 2013 at 06:48 PM.
  Reply With Quote
Old 20th November 2013, 07:43 PM   #6
colofan is offline colofan  United States
diyAudio Member
 
Join Date: May 2008
Location: Loveland, Colorado
I have many different options on midranges and making the enclosure from scratch. I have used driver before in both passive and active crossover systems just wondering about this new stuff with DSP about correcting the challenges out. I like the dispersion and sensitivity just trying to "tame" the driver a bit.

When I get done with the design and in testing mode I will post a bit more info on my specific driver set.

Time to go find my ball point pen. Thanks for the tips.

Also thanks for the tweak I will take apart the drivers and look for the mark.

Last edited by colofan; 20th November 2013 at 07:48 PM.
  Reply With Quote
Old 4th December 2013, 03:35 AM   #7
colofan is offline colofan  United States
diyAudio Member
 
Join Date: May 2008
Location: Loveland, Colorado
One other question is what DSP solution would you consider for "taming" the tweeter. I have seen a number of solution minidsp, dbx driverack...etc.

I already have the LinearXfilershop software so making digital filters not an issue. I can also test each tweeter in box to match up. The midrange I first though of since I have a couple of them is the Audax PR17-TX100 series though there is a new model out. I was also considering a FaitalPRO 6FE200 midrange.

This would be mated with a JBL 2118H for the midbass....I could go back to my passive/active crossover set and biuld a crossover but the thought of using a DSP to do some corrections with a computer and test data is inviting...

Anyone care to share their thoughts on building such a dsp based system?
  Reply With Quote
Old 4th December 2013, 01:57 PM   #8
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
I have a pair of Fane copies of the 2402. They are difficult to match, for sure. I am using digital crossover and EQ at the moment to tame them. It works, more or less.
  Reply With Quote
Old 4th December 2013, 03:58 PM   #9
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by colofan View Post
One other question is what DSP solution would you consider for "taming" the tweeter. I have seen a number of solution minidsp, dbx driverack...etc.

I already have the LinearXfilershop software so making digital filters not an issue. I can also test each tweeter in box to match up.
Other than reading a bit about the Mini DSP, no experience with it, but if the LinearXfilershop software works with it, the cost would be lower than a DBX Driverack. Most reports are the AD/DA sound good.

I use the DriverackPA for my PA systems, I like having a "no computer needed" device. It is nice to be able to save all the settings for the variety of different set ups I use.

The DRPA has 2 PEQ bands for low, and 3 PEQ for mid and high, plus a 1/3 octave L/R EQ, more than enough EQ and delay length for most systems.

One "interesting" detail of the DRPA is it reverses polarity from input to output.
It also puts out a terrible "shotgun" noise when turned off or power lost.

The DRPA+ reverses polarity on the mid output, but may have fixed the turn-off transient.

The more expensive DBX models don't have these "features".

Art
  Reply With Quote
Old 4th December 2013, 07:36 PM   #10
colofan is offline colofan  United States
diyAudio Member
 
Join Date: May 2008
Location: Loveland, Colorado
I am a little touchy about mini-dsp being in business 5 years from now. Maybe not an issue. Thanks for the feedback on the driverack systems and now they have come out with PA2 maybe wait a bit and do that....

Last edited by colofan; 4th December 2013 at 07:36 PM. Reason: spelling
  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
Sale: JBL 16" K145, JBL 8" 2118, JBL 2404 HF, Fane ST-5022 (Edgarhorn), Klipsch K55V ZERO1 Swap Meet 3 3rd February 2013 11:03 PM
2 - JBL 123A-1 -- 12" woofers -- from JBL L88, but also L100 Jimmy154 Swap Meet 3 26th October 2012 07:13 PM
Horn enclosures w/ JBL 2226 and JBL 375. burtcheca Swap Meet 0 2nd August 2010 01:21 PM
specs of jbl 046TI-1S and jbl 726gs panduro Multi-Way 2 21st June 2010 07:45 PM
RS-232 cable for DSP-Amp Digisynthetic DSP-1400 Sabbelbacke Parts 0 9th May 2009 09:33 AM


New To Site? Need Help?

All times are GMT. The time now is 10:16 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