# Use amp xovers with dsp?



## gumbeelee (Jan 3, 2011)

I was wondering how many of you use amp xovers when using a dsp instead of running full range?


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## percy072 (Feb 13, 2014)

Tweeters and mids are full range through the amp using DSP set crossovers...but I do dial back the LP filter on the sub amp channel to just over 60hz. 

Sub/Mid crossover set @ 90hz 24db slope with an MS-8 but I don't like the sound with the sub trying to go up that high (too much drone). Bit of a gap...but it works.


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## gstokes (Apr 20, 2014)

Using the integrated crossovers on the amplifier defeats the purpose of using the DSP to tailor the sound, the software based crossover/s in the DSP are much more refined, set the crossover/s to ALL FULL or THROUGH or whatever yours has and use the software based crossovers in the DSP..


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## gumbeelee (Jan 3, 2011)

gstokes said:


> Using the integrated crossovers on the amplifier defeats the purpose of using the DSP to tailor the sound, the software based crossover/s in the DSP are much more refined, set the crossover/s to ALL FULL or THROUGH or whatever yours has and use the software based crossovers in the DSP..


Thats what i do, i thanks its pointless to use the amps xoversi; i am just running a poll to see how many do also use the amps xovers as well as using the dsp; i thank u will be surprized at the amount of people that use the amps xovers as well;


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## Kazuhiro (Apr 28, 2015)

Can be an additional safety feature for your tweeter incase you dont have caps or your dsp resets


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## bugsplat (Nov 7, 2014)

DSP only. That's what's it's there for.


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## Shalym (May 13, 2015)

I voted Xovers


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## MetricMuscle (Sep 16, 2013)

If using an MS-8 and fully active, there aren't enough channels to use just the MS-8 crossovers and Andy actually suggests using a 4-channel amp and it's crossovers.
For instance,

MS-8 channel 1 and 2 feed a 4-channel amp which powers L/R tweeter and mid. 
MS-8 handles the HP @ 1KHz.
Amp handles the crossover between the tweeter and mid @ 3KHz.

MS-8 channel 3 and 4 feed a 2-channel amp which powers L/R mid-bass.
MS-8 handles the bandpass @ 80Hz to 1KHz.
Amp is set to pass thru or full range.

You have to make sure the DSP sees each of it's channels properly for TA so the xover points need to be appropriate to make it's job easier.
For instance, 1KHz and below is most important to TA where 3KHz and up is less about TA and more about actual height.

I don't think it's wise to use both DSP and amp crossovers unless you need to.


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## FordEscape (Nov 23, 2014)

*Hybrid XO setup with some on DSP and some on Amp (lacking the option I didn't vote in the poll)* _edit - the situation described by MetricMuscle above_

Here's why and I'd appreciate comments (on topic so I hope not a thread hijack) .... 

I'm testing this having just completed install of 3-way front, 1-way side and subwoofer with an MS-8, all active XO. That's 9 channels so here's what I'm trying using 2 MS-1004 amps and 1 MS 5001 amp:

MS-8 does the XO duty with filters OFF on the amps for channels 1 through 6 out to MS-1004 channels driving the front tweeters, front midrange and sides. Nothing special there.

MS-8 channels 7&8 are configured as Front Lo with output to the MS-5001. The pass-thru from the MS-5001 goes to the two MS-4001 channels driving the Front Lo speakers (call them midbass in this case).

For MS-8 Ch 7-8 the XO is set as a bandpass with the HP at the bottom frequency for the subwoofer and the LP set as the Front Lo/Mid XO (midbass to midrange). I then did the acoustic calibration of the MS-8 with the subwoofer disconnected.

After MS-8 calibration, on the MS-5001 driving the sub I set a LP XO/slope to cut-off the upper frequency sent to the subwoofer. On the MS-1004 channels driving the Midbass (Front Lo) I set a HP at a matching frequency/slope to keep the TM65's from getting too low frequency signal overlapping the subwoofer.

SO, all the XO's are on the DSP/MS-8 except the XO between Subwoofer and Midbass (Front Lo). The (hoped-for) effect is to have 9-channels of active XO with the subwoofer signal on the same timing as the Midbass (as set by MS-8). I felt this was appropriate to get the subwoofer signal routed through the MS-8 so all speakers have the same basic timing (everything gets the same MS-8 latency effect). *Because per Andy W the MS-8 does not do timing for a sub configured as a sub I'm figuring having the rear-mounted sub on the same timing as the front door midbass is OK.* The subwoofer level is then set using the output level control on the MS-5001.

I'm only two-days into this setup and am still listening and tweaking the Subwoofer level and the XO on the amps between the sub and midbass to get the sub blended.

FWIW the speakers are:
Sub - SI BM mkIV
Front Midbass - SI TM65
Front Midrange - HAT L3v2
Front Tweeter - HAT L1v2
Sides - Alpine SPS-610c

Comments / suggestions most welcome.


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## Alrojoca (Oct 5, 2012)

One big issue with sub amplifiers is that, the crossover's can not be defeated and the best you can do is set it to 300 hz and let the DSP take care of the rest.


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## FordEscape (Nov 23, 2014)

Alrojoca said:


> One big issue with sub amplifiers is that, the crossover's can not be defeated and the best you can do is set it to 300 hz and let the DSP take care of the rest.


Not sure if it qualifies as a "sub amplifier" but the XO's on the MS-A5001 can be defeated (Both HP and LP XO setting range is 20-140Hz @ 6, 12 or 24dB slope and "OFF" position). 

Maybe that's not typical but it's what I've got.


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## Alrojoca (Oct 5, 2012)

FordEscape said:


> Not sure if it qualifies as a "sub amplifier" but the XO's on the MS-A5001 can be defeated (Both HP and LP XO setting range is 20-140Hz @ 6, 12 or 24dB slope and "OFF" position).
> 
> Maybe that's not typical but it's what I've got.



Of course, the MSA amps have digital active crossover's built in and can be defeated, too bad they do not have TA and EQ if that was the case, there would not be a need for an external DSP. 

Can the DSP crossovers be defeated and just use EQ, TA etc from it, to use the Amp's crossovers?


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## FordEscape (Nov 23, 2014)

Alrojoca said:


> Of course, the MSA amps have digital active crossover's built in and can be defeated, too bad they do not have TA and EQ if that was the case, there would not be a need for an external DSP....


Yeah, but then we're talking a totally different product. Perhaps something there's a market for but inherently lacking many of the features that make the MS-8 nice for some of us (comprehensive all-channels auto EQ & TA). Granted not for everyone but hey, that's why there's choices in the market. In my case there's no way I'd have ventured into DSP with a unit requiring full-manual TA & EQ setup. That requires more time, learning, effort and tools than I've the patience or funds to acquire.

Yes, that's contradictory to the setup I've described above with my sub 'off of MS-8' in terms of auto EQ. And if I can't get the sub to blend fairly easily with my 'manual' efforts' I'll be altering the setup to put it back on a 'dedicated' MS-8 channel in hopes the MS-8 will manage that for me ;-)



Alrojoca said:


> ....Can the DSP crossovers be defeated and just use EQ, TA etc from it, to use the Amp's crossovers?


If referring to the MS-8, no, the XO's cannot be defeated as far as I know (I've not ventured into the 'hidden menu' searching for an XO-defeat though). The best you can do is carefully consider the channel setup feeding the amp(s) and set the corresponding MS-8 XO/slope outside of the range used on the amp, so the amp XO 'takes precedence' over the MS-8 XO setting. Conceptually the reverse of what you suggested in your earlier post for sub-amps with non-defeatable XO's.

Or, as I did, use a 'cascade' of XO's combining the MS-8 and the amp XO's to create the bandpass bracket desired.


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## Alrojoca (Oct 5, 2012)

It would be nice to have more amp's options without crossovers, and HU's without crossovers, they would cost less


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## subterFUSE (Sep 21, 2009)

No amp crossovers here. All done in DSP.


Sent from my iPhone using Tapatalk


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## mmnjtwa (Apr 6, 2015)

gumbeelee said:


> Thats what i do, i thanks its pointless to use the amps xoversi; i am just running a poll to see how many do also use the amps xovers as well as using the dsp; i thank u will be surprized at the amount of people that use the amps xovers as well;


I was definitely surprised to see 5 out of 17 using the crossover on their amps.


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## Mike Bober (Apr 11, 2013)

I have a Soundstream Ref. 1.1000 and a Ref. 4.920 and a 3sixty.3 and from what the Soundstream manual says its not possible to bypass the in amp x-overs, you can only open them up as wide as they will allow to pass thru. I have noticed while trying to set the dsp x-overs its been a bit difficult to get them working as i had them working amp x-overs only.


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## sienna12 (Mar 31, 2012)

I was JUST thinking about this a week ago! Are there any amps out there that have NO XO's or anything and just deliver, solid, quality power??


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## Alrojoca (Oct 5, 2012)

sienna12 said:


> I was JUST thinking about this a week ago! Are there any amps out there that have NO XO's or anything and just deliver, solid, quality power??




The Zapco LX series


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## subterFUSE (Sep 21, 2009)

My Sinfoni Prestigio class A has no crossovers.


Also, my old PPI Art Series amps had no crossovers.


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## Alrojoca (Oct 5, 2012)

My 80's alphasonik amp has no crossovers either


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## gstokes (Apr 20, 2014)

sienna12 said:


> I was JUST thinking about this a week ago! Are there any amps out there that have NO XO's or anything and just deliver, solid, quality power??


Stop limiting yourself to amps with no crossover, 99% of them have built-in crossover of some type but there is a setting to bypass the built-in crossover..

PPI Black Ice amplifiers deliver solid quality power and are fine choice, they're also very affordable..

Don't over complicate things, choosing an amplifier should be a rather simple process, find one that looks nice, has all the channels you need and the power that you want at ? ohms..

Run with it..


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## gckless (Oct 11, 2012)

I think you have to add an option to the poll of required to have amp crossover on, but set outside of a dsp's more restrictive setting. I know on my Ground Zero amps I can run them true full range, but my SS REF crossover cannot be turned off, rather I have to set the HPF below my actual HP setting.


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## Babs (Jul 6, 2007)

Only reason you'd want to use an amp's crossovers WITH a DSP is if you ran out of channels and used a pair of channels to split into four channels. This is all fine and dandy except you can only time-align and EQ those channels together. I'd only do this if both drivers were physically in alignment to listening position or the two drivers were something like an active coaxial maybe such as a rear-deck fill or something odd.


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## cobb2819 (Jan 13, 2011)

Full range or bypass or what have you on amps, but tweeter caps on tweeters, well outside of the crossover range, typically around the FS of the tweeter...because some protection isn't a bad thing.


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## Libba (Mar 11, 2020)

How about headunits crossovers? Set them through aswell?


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## F150Man (Apr 14, 2017)

percy072 said:


> Tweeters and mids are full range through the amp using DSP set crossovers...but I do dial back the LP filter on the sub amp channel to just over 60hz.
> 
> Sub/Mid crossover set @ 90hz 24db slope with an MS-8 but I don't like the sound with the sub trying to go up that high (too much drone). Bit of a gap...but it works.


Why isn't the sub on the DSP ?


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## Ge0 (Jul 23, 2007)

I have one excellent reason to defeat the amps filters and cross-overs. The analog circuits used to create the filters cause phase delays that the DSP does not compensate for. You are killing your staging if using caps or amplifiers filters and cross-overs.

If you tune your system with these filters and cross-overs active then you may be trying to correct problems in your DSP that normally would not be there. You're adding unnecessary digital filtering.

Ge0


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## Dremgragen (Jul 14, 2008)

I got nothing against Necros, second favorite class after Sorc.

My sub amp crossover can't be defeated, so I have to use it. Wouldn't if I didn't have to.

Sent from my SM-G950U using Tapatalk


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## ribrown (May 2, 2012)

Ge0 said:


> I have one excellent reason to defeat the amps filters and cross-overs. The analog circuits used to create the filters cause phase delays that the DSP does not compensate for. You are killing your staging if using caps or amplifiers filters and cross-overs.
> 
> If you tune your system with these filters and cross-overs active then you may be trying to correct problems in your DSP that normally would not be there. You're adding unnecessary digital filtering.
> 
> Ge0


Very interesting point. So I use my amps high pass crossovers as protection purposes well below the DSPs actual high pass filter for my front midbass, midrange, and tweeters. The DSP crossover filters are all 24dbLR. 
Does this mean that I am affecting the phase of these drivers by adding an additional 12db High Pass even though its outside of my DSPs crossover setting?
Thanks kindly for your input


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