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

Thoughts on DSP multiamp/attenuator setup?
Thoughts on DSP multiamp/attenuator setup?
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 8th January 2018, 10:26 PM   #1
badman is offline badman  United States
diyAudio Member
 
badman's Avatar
 
Join Date: Sep 2003
Location: Sunny Tustin, SoCal
Default Thoughts on DSP multiamp/attenuator setup?

I'm looking at my options for DSP crossovers, and the DBX Driverack Venu360 seems my strongest option.

DriveRack VENU360 | dbx Professional Audio

The problem with that option is that because it's for a triamp setup, and I'm not running a mixer and matching levels etc, I need a volume control post-unit. Pre-unit would lead to low input levels and lead to noisy/truncated performance.

Right now I'm leaning towards this minimalist solution-

Overview

Combined with the breakout cables needed, that puts me at around $1500 all-in- not a piddling investment but having a good volume control and full DSP with either line-level analog or AES/EBU inputs will be extremely flexible and ensure that I'm not feeding the driverack with low-level signals that will underperform when I'm using the analog input.

I don't really want to build a 6ch volume control using premium goodies, or turn more than one knob, so the SPL Volume 8 seems to be a solid choice (knowing that it's single-ended on the potentiometer).

Any thoughts? Anyone found a solid 6ch balanced volume control option besides this? Is there a $1500 DSP I'm missing that would do stereo 3 ways, well, and not require the additional box? One alternative is analog XOs, but I like the power and flex that the Venu affords me for other uses besides this project.
__________________
"The dawn of Bose created the "Man Cave" and reduced testoterone levels worldwide by 18.5 per cent" Peteleoni
  Reply With Quote
Old 8th January 2018, 10:32 PM   #2
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
This a dubious claim from their blurb :

"In contrast to passive volume controls which alter the phase and frequency response there is no alteration in sound with an active volume control"

I use this Alps Rk16816mg 6-way High-end Motor Potentiometer 10k Logarithmic | eBay with a Behringer DCX2496
__________________
Woofer Assisted Wideband is the New Testament renounce the anachronistic acronym FAST

Last edited by scottjoplin; 8th January 2018 at 10:56 PM.
  Reply With Quote
Old 9th January 2018, 12:58 AM   #3
mark100 is offline mark100  United States
diyAudio Member
 
Join Date: Dec 2010
Hi, I can't really tell what you're going for...
The venue 360 should have input gain control , as well as output levels...
.......and with the remote apps, doesn't that give you all the volume control you need?
  Reply With Quote
Old 9th January 2018, 03:16 AM   #4
CharlieLaub is offline CharlieLaub  United States
diyAudio Member
 
Join Date: Mar 2007
Location: Michigan
Quote:
Originally Posted by badman View Post
I'm looking at my options for DSP crossovers, and the DBX Driverack Venu360 seems my strongest option.

DriveRack VENU360 | dbx Professional Audio

The problem with that option is that because it's for a triamp setup, and I'm not running a mixer and matching levels etc, I need a volume control post-unit. Pre-unit would lead to low input levels and lead to noisy/truncated performance.

Right now I'm leaning towards this minimalist solution-

Overview

Combined with the breakout cables needed, that puts me at around $1500 all-in- not a piddling investment but having a good volume control and full DSP with either line-level analog or AES/EBU inputs will be extremely flexible and ensure that I'm not feeding the driverack with low-level signals that will underperform when I'm using the analog input.

I don't really want to build a 6ch volume control using premium goodies, or turn more than one knob, so the SPL Volume 8 seems to be a solid choice (knowing that it's single-ended on the potentiometer).

Any thoughts? Anyone found a solid 6ch balanced volume control option besides this? Is there a $1500 DSP I'm missing that would do stereo 3 ways, well, and not require the additional box? One alternative is analog XOs, but I like the power and flex that the Venu affords me for other uses besides this project.
If instead of using HARDWARE to do DSP you used SOFTWARE you could pay a fraction of the cost, and do the volume control/balance in software, even interface to an external knob if you want to set global volume levels. Ten years ago this was the way to go, but not anymore. You now need a small, low cost linux computer, some free software, a multichannel onboard sound card or external USB multichannel DAC (and ADC if you want to process the audio from other analog components), and some time to bring it all together. This page is an example of what you can do:
Digital Crossover/EQ with Open-Source Software: HOWTO | Richard's Stuff

I only use this approach now for loudspeaker crossovers and DSP where I previously (10 years back) used a Behringer DCX2496 and then (5 years back) some different miniDSP boxes. I can do more and different stuff under linux, and that makes it a more powerful and versatile solution for my systems.
__________________
Visit my Audio Web Page <<--CLICK TO LEARN MORE-->> Get my LADSPA plugins
  Reply With Quote
Old 9th January 2018, 07:43 AM   #5
xandresen is offline xandresen
diyAudio Member
 
Join Date: Feb 2014
If you want a self-contained, ready to roll solution (which the Linux way is not), then check out miniDSP products.

I use their 4x10 to do a stereo three way crossover (it can handle four way). There is a master digital volume at the digital processing output, controlled with any IR remote or the front panel knob. See their website for products/info.

Creating a DSP crossover requires different software tools than passive xover and ideally these tools match the hardware you buy. There is an excellent Excel based program to do almost all the work with the family of miniDSP products I use.

Interestingly the author of this program is (wait for it) Charlie Laub!

Charlie have you written a page somewhere with the tradeoffs between miniDSP and the Linux box solution?
  Reply With Quote
Old 9th January 2018, 02:44 PM   #6
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: SW Florida
Thoughts on DSP multiamp/attenuator setup?
Quote:
Originally Posted by badman View Post
I need a volume control post-unit. Pre-unit would lead to low input levels and lead to noisy/truncated performance.
Not really, if you set it up right. I've run that way for years and it's every bit as good, if not better, than analog control post x-over.

If you set up your gain structure properly, you'll only need about 10dB of volume control. Since most software will be working in 32 or 64 bit float, that's not a problem. Your DAC might be 24 bit (still no problem) with an effective 20 bits of S/N. That's still huge.

Digital attenuation is a problem I worried about for years, until I actually listened to it and measured it. Doing it right isn't difficult and the results are worth it.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 9th January 2018, 03:34 PM   #7
badman is offline badman  United States
diyAudio Member
 
badman's Avatar
 
Join Date: Sep 2003
Location: Sunny Tustin, SoCal
Thanks for the thoughts guys. Pano, I need this to be relatively flexible for different configs- I can't always run a decent input voltage IF I'm controlling level on the input side. 10dB won't cut it for me on control range.

Charlie, PC based is stronk for sure- I get hung up on a good multichannel balanced dac/sound card, as well as concerns on noise etc, but I guess those can be mitigated in a modern setup. I'd want something I can leave up to enable the wifely unit to operate things without too many headaches.

Mark: I haven't seen a good master gain solution in the venu documentation anywhere. The presence of that would go a long way, I'll keep looking.

MiniDSP doesn't quite meet what I think I want in terms of power and flexibility, same with behringer and a vol pot.

So PC needs some more review, I'm not sure I'm okay with adding the SPL unit just to have a decent VC, even though it seems well-suited to this app.
__________________
"The dawn of Bose created the "Man Cave" and reduced testoterone levels worldwide by 18.5 per cent" Peteleoni
  Reply With Quote
Old 9th January 2018, 04:03 PM   #8
mark100 is offline mark100  United States
diyAudio Member
 
Join Date: Dec 2010
Quote:
Originally Posted by badman View Post

Mark: I haven't seen a good master gain solution in the venu documentation anywhere. The presence of that would go a long way, I'll keep looking.
Yeah, that Venue360 manual is one bugger to figure out IMO !!

It's a bit more $$, but I have a Danley SC-48 (Linea-Reseach ASC-48) that I can highly recommend. 4x8 analog or aes3. Great global/individual control/routing, rms and peak limiting, and the equivalent of linear phase LR24s that can be moved on the fly, with timing staying in place between output channels. it's pretty slick...
  Reply With Quote
Old 9th January 2018, 04:17 PM   #9
neo2015 is offline neo2015
diyAudio Member
 
Join Date: Jan 2015
The dB-Mark XCA48 has some interesting specs and its cheaper (485) than the Venue 360:
  • DAC Chip: Texas Instruments PCM1798
  • ADC Chip: Asahi Kasei AK5388
  • DSP Chip: Texas Instruments TM320C6726
  • Op Amps: Texas Instruments MC33078, ST Microelectronics MC33079

I have a miniDSP 2x4HD that i will use for a 2 way crossover for a TPL-150H + AE TD12M, but some users have reported some hiss with high sensitivity CD's, so if face the same with the miniDSP i'm considering trying the dB-Mark.
  Reply With Quote
Old 9th January 2018, 05:19 PM   #10
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: SW Florida
Thoughts on DSP multiamp/attenuator setup?
Quote:
Originally Posted by badman View Post
Thanks for the thoughts guys. Pano, I need this to be relatively flexible for different configs- I can't always run a decent input voltage IF I'm controlling level on the input side. 10dB won't cut it for me on control range.
Understandable, it can be source dependent.

I don't use a CD player, doing all file playback from hard drive via a software player. For phono I used a preamp with volume control, then a stand alone audio card to go from analog to SPDIF, then on to the crossover. With all that I was surprised to find that a range of 10dB was plenty. I expected maybe 20dB or more.

IME, getting the system set up so that every source can be used over a volume range of ~12dB is well worth the effort. Digital volume control is super clean.
__________________
Take the Speaker Voltage Test!
  Reply With Quote

Reply


Thoughts on DSP multiamp/attenuator setup?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
Thoughts on a unique OB setup badman Multi-Way 4 18th August 2017 10:22 PM
Thoughts/ideas for car audio setup santiu Car Audio 3 17th April 2017 07:35 AM
Need some thoughts on setup with multi-subs. apocalypseon Multi-Way 1 1st December 2013 06:12 PM
New NAS-PC Setup - Thoughts, comments? BadgerManSG PC Based 1 22nd January 2013 08:47 PM
which amp for multiamp patriz Solid State 0 4th June 2002 10:53 PM


New To Site? Need Help?

All times are GMT. The time now is 07:20 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