Biamping with analogue crossover and TWO crossover points?!

[Psilonaught]

As some of you in this section will know, I'm running a 2-way bi-amp setup into a sublime audio crossover. Yesterday the high-level section of my system stopped working when I powered up the system. I eventually ruled out all hardware up to the crossover, so it looks like it has developed a fault I so i need to ship it back to the US for repair/warrantee replacement. This crossover has a resistor card system to apply the filter.

When I opened the unit, I was reminded that inside, you have space for two crossover cards, one for low pass and one for mid/high pass. As per the instructions in the magnepan 20.1 manual, I bought 100Hz and 300Hz cards, one for each slot.

But the system is a 2-way bi-amp setup, so inside the unit I set the crossover to (2-way). This presumably means the 300Hz crossover point is ignored I've just realised?!

Furthermore, looking at the front and back of a dbx crossover 234xs that I intend to buy as a stand-in, again I would need to set the crossover the 2-way and I would only be able to apply a single low-pass at 100Hz

Therefore my question is, why does magnepan state the need to apply low AND high pass filters in a 2-way setup- no analogue crossover would allow you to do that right? I could only apply ONE low pass filter

See this section of the manual

 

[Psilonaught]

I think I have answered my own question, I saw on another forum that a fellow 20.1 owner uses a marchand crossover

This crossover can apply multiple BANDS on 2-way. I didn't realise you can buy analogue crossovers with multiple bands

crossover design that provides individual outputs for 1, 2, 3 or 4 frequency bands on the 1- 2- 3- and 4-way models respectively

 

[Sumdumgi]

The latest post pane on an iPhone puts a different light on your question 😂

 

[dave]

Therefore my question is, why does magnepan state the need to apply low AND high pass filters in a 2-way setup- no analogue crossover would allow you to do that right? I could only apply ONE low pass filter

A crossover for a two way speaker consists typically of a high pass filter for the upper range, and a low pass filter for the lower range.

Where is that Tuga when we need him with a handy graph.

 

[Tony_J]

A crossover for a two way speaker consists typically of a high pass filter for the upper range, and a low pass filter for the lower range.

That is correct. It is possible and sometimes desirable for the high pass and low pass frequencies and/or slopes to be different, but your typical analogue crossover with dials on the front to select crossover freq don't allow this.

 

[Non-Smoking Man]

Hi James..
In a 2 way stereo crossover only 1 module is required as you only get 2 channels - one channel above the crossover point and one channel below.
In this arrangement your bass speaker is allowed to play down to its Fs or put another way it is playing freely as low as it can go. As Tony says this is standard stuff and all most 2 ways can do. But in a more adjustable 2 way it seems its possible to stop the low frequency driver playing itself as low as it can go by putting another filter in to stop subsonics on warped records etc. But that's neither common nor really necessary. That might be at , say, 30 Hz.

So, it looks like you have installed 2 crossovers where there is only provision for one. So you may have confused the unit.

Pick the frequency you want to suit your drivers and insert that 'card' and extract the other one.
It will be obvious to you which one to choose - 100Hz or 300 Hz. (If the bass is a direct radiator it will most likely be 300Hz, but if you are running a subwoofer below a full frequency mid/bass its probaly 100Hz (where subs are usually crossed - at least if they are horns!)

I use the Marchand DX9 2 way stereo (U.S.A.) which uses modules you insert instead of cards (just the one!). Its actually piggybacked with a 4 way Ashly to make 5 channels, but that's irrelevant to this thread..

Jack

 

[newlash09]

Hi @Psilonaught ..fondly hope you won't mind me hijacking your post for a little while sir. As I think it might benefit a larger audience, with an interest in active crossovers.

@Non-Smoking Man ..can you please explain the implementation of your crossovers sir. Ive been considering going active with the latest Deqx processors, yet to be launched this last quarter, probably just in time for Christmas 😂

But I will admit that iam paranoid about the ADC conversion from my turn table, besides I also fear they will be very steeply priced. . So I was considering stitching up a few crossovers I have at hand. Two are digital, ( a DSpeaker antimode 2.0 and a minidsp SHD). These will only be doing the 10inch bass driver in my speaker, and the dual 15inch ripole subs iam building for the lower bass.

Then I have a fully analogue alpine 3672, for the mid and tweeter. With the idea that mids and treble remain unmolested from the ADC conversion. But the issue is that, being digital both the minidsp SHD and DSpeaker can add substantial time lag to the bass, due to their processing latency in the time domain. Thanks in advance to kindly let me know sir.

 

[Non-Smoking Man]

Eek, Mano, that's a toughie, especially as I'm not competent to discuss digital crossovers as I haven't researched them, dont like them, dont need them and dont rate them. (And I have heard them - the Nadja is a separate case..)

Its analogue all the way..
(No analogue to digital - its against my religion!)


(The Alpine? What's that?)

If your source is a turntable and you have multiway speakers with separate amps then you need an active analogue crossover, such as an Ashly, or a Rane or Sony, or Marchand. etc.

You acquire the model that suits your system e.g., 3 way stereo, 4 way stereo etc.

Have a look at my 'A 5 way horn system' for more background and more detail as to how Ive gone about it.

There's more than one way to do it, but this is my way. What I dont and cant have with ANALOGUE active crossovers is precise TIME ALIGNMENT, but there are always trade offs and I'm happy with a completely balanced (and you will have to be balanced throughout to use such crossovers) analogue system, that has vertical and side alignment by eye - and so are my guests, it seems..

An active system doesn't have to be horns of course..many domestically acceptable speaker systems use direct radiators for bass (spacesaving) and horns for mids and tops - but you know this Mano..(I know you read my posts).

I could be accused of being oldfashioned, not up with current trends, but I specialise and apply the knowledge and experience Ive accrued over the years within a restricted budget and shrewd purchases.

Jack

 

[Non-Smoking Man]

I think I have answered my own question, I saw on another forum that a fellow 20.1 owner uses a marchand crossover

This crossover can apply multiple BANDS on 2-way. I didn't realise you can buy analogue crossovers with multiple bands

crossover design that provides individual outputs for 1, 2, 3 or 4 frequency bands on the 1- 2- 3- and 4-way models respectively

All this means is that you can buy different modules that provide different crossover points - e.g., 80 Hz to use a subwoofer, 1.5 Khz to introduce a supertweeter etc. You still only insert ONE module in a 2-way crossover to give you 2 channels. 2-way crossovers are typically used for supertweeters or subs. For a wholesale multiway system you go for a 4 way unit, or 2 x 3 ways monos to provide 5 ways, or piggyback for 5 ways.

Jack

 

[Psilonaught]

Its analogue all the way..
(No analogue to digital - its against my religion!)

Snap, I'll never use a digital crossover for that reason. I apply by EQ upstream of my DAC at the audio processing stage, you definitely don't need a digital crossover to apply EQ!

Sublime Audio said I've got a bad opamp so my crossover is on the way to the US for repair.

For simple 2-way active crossover Sublime Audio is top of the tree.

https://sublimeacoustic.com/products/k231-stereo-3-way-active-crossover