Evening everyone.
I couldent find a forum tread for my specific question. So im trying. Bear with me. 🙂
Im building two Aleph 3 and two Aleph 5 in the same chassis. and plan to put an active crossover inside the amplifier chassis as a part of the input stage.
I have 4 toroids 300va and 500va and so on 🙂 and about 576,000UF in total.
.
Question is. my speakers costs 7000$, and i really really really dont want to open them up to bypass the passive crossovers. (they have biwire terminals)
Allso theres both a ribbon and normal tweeter. so i kind have to use the internal crossover. for the highs.
Will there even be a noticeble difference? or would it hurt the sound doing it like this?
.
I was designing the amp with the midset that if the HZ (800) was the same all the internal crossover did, was send the signal on. as there was nothing to filter.
Regards Morten.
I couldent find a forum tread for my specific question. So im trying. Bear with me. 🙂
Im building two Aleph 3 and two Aleph 5 in the same chassis. and plan to put an active crossover inside the amplifier chassis as a part of the input stage.
I have 4 toroids 300va and 500va and so on 🙂 and about 576,000UF in total.
.
Question is. my speakers costs 7000$, and i really really really dont want to open them up to bypass the passive crossovers. (they have biwire terminals)
Allso theres both a ribbon and normal tweeter. so i kind have to use the internal crossover. for the highs.
Will there even be a noticeble difference? or would it hurt the sound doing it like this?
.
I was designing the amp with the midset that if the HZ (800) was the same all the internal crossover did, was send the signal on. as there was nothing to filter.
Regards Morten.
If you do not open the speakers, and use two amplifiers to power each section, while utilizing inner passive crossover, this is called 'biamping'.
This has nothing to do with active crossover.
You need the feed both amplifiers the same signal.
If you place active crossover infront of amplifiers, it will sound weird, because you have two crossovers.
This has nothing to do with active crossover.
You need the feed both amplifiers the same signal.
If you place active crossover infront of amplifiers, it will sound weird, because you have two crossovers.
Passive biamping… not nearly as effective as active biamping, but means you do not need to figure out what was done in the passive that has to be replicated in the active.
dave
I plan to build an acrive crossover into the amplifiers input stage. Så the amps dont have to amplify the signals they dont need to
No, you'll double filter. Filters don't cut the signal like yes and no.. they roll it off on a slope. You'll have increased group delay from the steep slope, and if one of the crossovers isn't tuned properly you'll keep the error.
What you propose is likely to be worse than before if you don't do it as well as it was originally done.. whether you remove the original crossover or not.
If you don’t remove the passives the actives will be more or less useless except for how running the active effectively in series with the passive, the FR will likely get screwed up (what Allen said).
dave
Okay. So in reality. Its pritty pointless having 4 channels in the amp in the first place?
I was told that passive biamping without an active crossover was a waste of money. Even if its class a.
I was told that passive biamping without an active crossover was a waste of money. Even if its class a.
Imho, this is not true. It probably originates from a deaf objectionist. I meant objectivist 🙂
I have built alot of Active Crossovers in years gone by for home equipment & in the PA world learning how they sound & when they blow up due to being over-driven. In the 1990's it was alot harder to calculate the Frequency crossover points, as all I had was the pie formulas, now the are online calculators to work it out for you & each R/C filter is 6db per octave.
If you was going to make an active crossover & you still had the passive crossover inside the speaker then I would choose higher frequency roll off for the bass & a lower frequency for the mid, tops which are away from the the speaker crossover frequencies. I still think it is pointless in doing because of the speaker box crossovers, but the amps would run more efficient with less bandwidth to amplify.
In the picture is one of my older test crossover circuits showing a design layout from above & the only thing missing is the 100k pots, which form part of the output circuit, this incluse a gnd loop isolation transformer as there is alot more ground loops to consider as you add more amps picking up noise...
If you was going to make an active crossover & you still had the passive crossover inside the speaker then I would choose higher frequency roll off for the bass & a lower frequency for the mid, tops which are away from the the speaker crossover frequencies. I still think it is pointless in doing because of the speaker box crossovers, but the amps would run more efficient with less bandwidth to amplify.
In the picture is one of my older test crossover circuits showing a design layout from above & the only thing missing is the 100k pots, which form part of the output circuit, this incluse a gnd loop isolation transformer as there is alot more ground loops to consider as you add more amps picking up noise...
Attachments
So what you are saying is. Get active crossovers that is 1000 ish hz for bass and 700 ish for highs?
Part of the advantage of active crossovers is not wasting amp power on frequencies not needed by the driver. No sense in sending bass to a tweeter so if that range is removed from the amp its power can be used in the high range. It also makes the amp run more easily because it’s not making the bass. If you make your active crossover at the same frequency as the passive you will often get odd unwanted results. By moving the frequency away from the speaker’s internal frequency you are less likely to get an interaction and still get most of the biamp benefits. Make the active crossover have the same slope as the passive so they don’t “run into each other”.
I apriciate the responses. I really do.
The conclusion to this is that im going to buy crossovers that dosent fit the speakers so the bass is 800hz in the speakers so ill pit in a 1200hz crossover. And vise versa. Thank you all
The conclusion to this is that im going to buy crossovers that dosent fit the speakers so the bass is 800hz in the speakers so ill pit in a 1200hz crossover. And vise versa. Thank you all
What is the actual crossover frequency of the speaker as is? You want to make the woofer higher and tweeter lower.
It can maybe make an improvement. Both channels driving the loudspeaker should be identical.
That is the kind of statement made by someone who has actively biamped.
One of the big benefits of active is that it removes all the reactive circuitry inside the loudspeaker. This makes for happier amplifiers.
Information loss will also generally be less for a well designed active XO than for a passive XO.
A passive XO will often have “shaping” components in it, you may have to pay attention to this. This components for shaping the driver’s impedance likely do not matter, FR shaping does.
What $7k loudspeaker are you afraid to pull the XO out of? You actually don’t have to remove it, just bypass it. Disconnect the wires at the terminals and those connected to the drivers. Get some (good) new speaker wire and connect teh drivers directly to the terminals.
dave
A screenshot from here. There is info on the page with power distribution by frequency in a sampling of artists as well.
https://www.t-linespeakers.org/oddsends/biamp/Index.html
dave