Configure a Pre-Pro as active crossover?

[marten]

I haven't owned a pre-pro.  Is it possible to set up a typical av Pre-Pro to serve as a sort of active crossover?   

 

More specifically configure it to:

1) send two L-R main channels to woofers using e.g. a 24dB/oct low pass filter
2) send two L-R main channels to tweeters using e.g. a 24dB/oct high pass filter

This to serve 2-channel delivery rather than full surround delivery.

 

I know most pre-pro's allow you to set up parametric equalisation filters, but I don't know whether you can set up the far simpler low/high pass filters.
Also you would need some routing configurability to send L-R mains to pre-out ports normally used for surrounds.

 

[cwt]

1 hour ago, marten said:

I haven't owned a pre-pro.  Is it possible to set up a typical av Pre-Pro to serve as a sort of active crossover?   

 

More specifically configure it to:

1) send two L-R main channels to woofers using e.g. a 24dB/oct low pass filter
2) send two L-R main channels to tweeters using e.g. a 24dB/oct high pass filter

This to serve 2-channel delivery rather than full surround delivery.

 

I know most pre-pro's allow you to set up parametric equalisation filters, but I don't know whether you can set up the far simpler low/high pass filters.
Also you would need some routing configurability to send L-R mains to pre-out ports normally used for surrounds.

 

Yes its possible but you would have to spend the dollars atm . A storm audio or trinnov altitude have the comprehensive bass management required . The storm audio 16ch  has very comprehensive b/m but aimed at the full channel compliment 

• Fully configurable speaker management
• Flexible channel mapping and routing
• Unlimited multi-subwoofer channels
• Multi-way active and passive speaker management

It becomes a bit easier if you have an outboard active xover . The new JBL Synthesis sdp55 is around US $6000 and has Dante digital  out over 1 cable[ that can handle 160 odd channels]  so may be compatible with an aes digital crossover ? No expert here though ; dante is just coming over from the pro world Have a look here for an 8ch model

https://www.jblsynthesis.com/products/electronics/equalizers/SDEC-3500-.html?cgid=equalizers&dwvar_SDEC-3500-_color=Black-GLOBAL-Current

 

 

Edited January 16, 2020 by cwt

[andyr]

2 hours ago, marten said:

I haven't owned a pre-pro.  Is it possible to set up a typical av Pre-Pro to serve as a sort of active crossover?   

 

More specifically configure it to:

1) send two L-R main channels to woofers using e.g. a 24dB/oct low pass filter
2) send two L-R main channels to tweeters using e.g. a 24dB/oct high pass filter

This to serve 2-channel delivery rather than full surround delivery.

 

I know most pre-pro's allow you to set up parametric equalisation filters, but I don't know whether you can set up the far simpler low/high pass filters.
Also you would need some routing configurability to send L-R mains to pre-out ports normally used for surrounds.

 

 

WTF is a "pre-pro"? 

 

Andy

 

[Batty]

I believe it is a pre amp and power amp Andy, odd I know.

 

Or even a Pre processor.

Edited January 16, 2020 by Batty

[marten]

An AV Pre-Pro is an AV preamp and surround processor, with pre-outs only (no power amp included like an AV receiver).

 

 

[Batty]

Thanks

[andyr]

11 hours ago, marten said:

An AV Pre-Pro is an AV preamp and surround processor, with pre-outs only (no power amp included like an AV receiver).

 

Aaah, OK.  Thanks. 

 

Back to your original Qu:

 

Is it possible to set up a typical av Pre-Pro to serve as a sort of active crossover?   

 

More specifically configure it to:

1) send two L-R main channels to woofers using e.g. a 24dB/oct low pass filter
2) send two L-R main channels to tweeters using e.g. a 24dB/oct high pass filter

This to serve 2-channel delivery rather than full surround delivery.

 

I think you will have to ask this Qu of the mfr of the specific pre-pro you're interested in.

 

Andy

 

[AudioGeek]

I maybe missing something here but dont virtually all AV processors do this? As in they all have 2.1 or 2.2 stereo modes?

May not have absolute control over crossover type, but then they all have some form of room/bass correction eg. Audyssey, dirac etc.

 

You can set different crossover points for sub and mains - particularly if your mains also have good low output ie. more bass sources

[cwt]

2 hours ago, AudioGeek said:

I maybe missing something here but dont virtually all AV processors do this? As in they all have 2.1 or 2.2 stereo modes?

May not have absolute control over crossover type, but then they all have some form of room/bass correction eg. Audyssey, dirac etc.

 

You can set different crossover points for sub and mains - particularly if your mains also have good low output ie. more bass sources

That's par for the course when splitting up individual channels to hi pass and low pass to suit say2.1; 5.1 or 7.1 but Marten wants to send duplicates of the L/R channels I read to individual drivers [biamping] ; so this requires active crossovers 

Its more of a niche thing for a multichannel device especially when you have dolby atmos 9.1.6 etc to find outlets for. If it doesn't have to be an all in one component the Lyngdorf TDAI2170 also has biamping capabilities

 https://lyngdorf.com/wp-content/uploads/2019/12/lyngdorf-audio-how-to-do-bi-amping-with-the-tdai-2170-and-sda-2400-amplifiers.pdf

[Snoopy8]

21 hours ago, marten said:

I haven't owned a pre-pro.  Is it possible to set up a typical av Pre-Pro to serve as a sort of active crossover?   

 

More specifically configure it to:

1) send two L-R main channels to woofers using e.g. a 24dB/oct low pass filter
2) send two L-R main channels to tweeters using e.g. a 24dB/oct high pass filter

This to serve 2-channel delivery rather than full surround delivery.

 

I know most pre-pro's allow you to set up parametric equalisation filters, but I don't know whether you can set up the far simpler low/high pass filters.
Also you would need some routing configurability to send L-R mains to pre-out ports normally used for surrounds.

I am puzzled by why you want to spend a lot more for a prepro than using say a MiniDSP 2x4HD? 

[andyr]

1 hour ago, Snoopy8 said:

I am puzzled by why you want to spend a lot more for a prepro than using say a MiniDSP 2x4HD? 

 

Agreed, S!    When the 2x4HD will do everything the OP asked - and more!  All for only USD205.

 

See here, @marten:  https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4-hd

 

Andy

 

[AudioGeek]

Ah, i see now. 

Yes a minidsp or deqx would fit the bill.

 

What speaker though?

[marten]

12 hours ago, AudioGeek said:

I maybe missing something here but dont virtually all AV processors do this? As in they all have 2.1 or 2.2 stereo modes?

Could be right, but my understanding of the 2.1 feature of most low/mid priced pre-pros is that they:
1) usually output the subwoofer in mono, whereas the requirement is for stereo woofers
2) often limit the subwoofer cut-off frequency to something under 200Hz, whereas crossing to a woofer may need north of 800Hz.

Know of any one that does subwoofers in stereo with choice of cutoff freq up to 1000Hz?

 

8 hours ago, Snoopy8 said:

I am puzzled by why you want to spend a lot more for a prepro than using say a MiniDSP 2x4HD

Because I have offered to sort out some options for an elderly family member.  It would be nice if he could cover home theatre and 2-channel with one box, and not need to hook up a PC to make adjustments as you do with miniDSP.  

 

I'm just checking in SNA's specialist AV forum to avoid having to read AV manufacturer's manuals.

 

In my own system I don't use miniDSP but I do play with outboard crossovers using a 6-channel usb DAC and also some pro audio 3-way crossovers. I don't do HT.

 

 

To Colin (cwt) - thanks for your informative post.  That JBL Synthesis covers a lot of bases, even throwing in Dirac Live room correction; very impressive.  Though at 6k in the US, it's Australian price is going to be well out of range for my man.

 

I am a bit surprised that, apparently, one cannot do the low/high pass filters for a crossover with a garden variety AV Pre-Pro, given it already has a cpu, operating system and app software to handle more complex functions like parametric eq and surround decoding for DTS, ATMOS etc.   So the hardware and software infrastructure is already all there, just needs an extra bit of application software to do simple high/low filters and route the outputs.  

 

 

Edited January 17, 2020 by marten

[Snoopy8]

7 hours ago, marten said:

Because I have offered to sort out some options for an elderly family member.  It would be nice if he could cover home theatre and 2-channel with one box, and not need to hook up a PC to make adjustments as you do with miniDSP.  

......

 

....  Though at 6k in the US, it's Australian price is going to be well out of range for my man.

It was impossible to guess what your context was based in your initial post!  We now know it is for an elderly family member and budget less than USD9K

7 hours ago, marten said:

Could be right, but my understanding of the 2.1 feature of most low/mid priced pre-pros is that they:
1) usually output the subwoofer in mono, whereas the requirement is for stereo woofers
2) often limit the subwoofer cut-off frequency to something under 200Hz, whereas crossing to a woofer may need north of 800Hz.

Know of any one that does subwoofers in stereo with choice of cutoff freq up to 1000Hz?

 

......

In my own system I don't use miniDSP but I do play with outboard crossovers using a 6-channel usb DAC and also some pro audio 3-way crossovers. I don't do HT.

 

I am a bit surprised that, apparently, one cannot do the low/high pass filters for a crossover with a garden variety AV Pre-Pro, given it already has a cpu, operating system and app software to handle more complex functions like parametric eq and surround decoding for DTS, ATMOS etc.   So the hardware and software infrastructure is already all there, just needs an extra bit of application software to do simple high/low filters and route the outputs.  

Applying what you do with your stereo to a HT system is not the right approach.  Especially for an elderly person to do both HT and stereo.  

 

A garden variety AVR will do the job,  but there are NO AVRs or prepros which can do what you want based on your specs.  

 

Having stereo woofers for HT and cross overs at 800/1000 Hz does not make sense.  There are no stereo bass tracks in movies and bass will not integrate well at such high crossovers.  Integration of  dual subs is best done with mono to improve the bass and easiest with package software like Dirac.  You can use full range speakers for the fronts and not use subs, but subs give the movies the additional punch.

[marten]

3 hours ago, Snoopy8 said:

Having stereo woofers for HT and cross overs at 800/1000 Hz does not make sense.  There are no stereo bass tracks in movies and bass will not integrate well at such high crossovers. 

Thanks for the input Snoopy, but it's not that complicated - he has bought a 5.1 Kef speaker set for HT. 

But, he also has a beloved pair of heavy, active 2-ways, one of which has bad electronics.  So an active crossover will allow us to play around with to see if we can match the sound of the amp-less one with the good one before deciding how to proceed with those.  Even though he lives far away, we look forward to the crossover fiddling.

 

But this thread isn't to delve into his scenarios - as mentioned, I'm just keen to learn about the high/low filter features that may or may not exist on "typical", garden variety AV pre-pros to avoid having to download and read AV manufacturer's manuals.

 

 

[Snoopy8]

13 minutes ago, marten said:

Thanks for the input Snoopy, but it's not that complicated - he has bought a 5.1 Kef speaker set for HT. 

But, he also has a beloved pair of heavy, active 2-ways, one of which has bad electronics.  So an active crossover will allow us to play around with to see if we can match the sound of the amp-less one with the good one before deciding how to proceed with those.  Even though he lives far away, we look forward to the crossover fiddling.

 

But this thread isn't to delve into his scenarios - as mentioned, I'm just keen to learn about the high/low filter features that may or may not exist on "typical", garden variety AV pre-pros to avoid having to download and read AV manufacturer's manuals.

Garden variety AVRs and prepros will have cutover, typically between 80 and 300 Hz, mono sub output, some with dual mono outputs.  The better ones will have room correction software like Dirac, Anthem Room Correction (both which I can recommend).

 

So, to answer your question, filters do exist in all AVRs and prepros and can be set manually.  They will not do 800/1000 Hz cutoff.  The only way to do that is get a seperate DSP device. Or look for a Pro audio processor, which I am not familiar with.