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Active Crossover [message #46894]

Sun, 15 May 2005 11:12

Malcolms
Messages: 6
Registered: May 2009

Esquire

Hello, I finished building a pair of stage 4pi's using the eminence drivers. I just aquired a behringer dcx2496 digital crossover. I would like some info as to where to set the crossover points. I will be bi-amping using 60w tube mono blocs for the highs and a bryston 4b for lows. Any help would be greatly appreciated. I will post pics of speaks soon. Speak are finished in solid cherry and baltic birch.

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Re: Active Crossover [message #46895 is a reply to message #46894]

Sun, 15 May 2005 11:23

spkrman57
Messages: 522
Registered: May 2009

Illuminati (1st Degree)

60 watts of power for the horns, what stadium are you using these in?

Seriously, I run my 4 pi-pro on SEP EL34(9 watts/chnl) and when I need the serious output, I use my MC-240(40WPC) and it threatens to blow the windows out.

Keep us posted on the results!

Ron

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Re: Active Crossover [message #46898 is a reply to message #46894]

Sun, 15 May 2005 20:18

Wayne Parham
Messages: 18787
Registered: January 2001

Illuminati (33rd Degree)

Set it between 1.2kHz and 1.6kHz, no lower for the PSD2002. You want to be able to set the LF and HF points independently, if possible. Also, you'll want to be sure to use tweeter compensation or it will not sound good.

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Re: Active Crossover [message #46903 is a reply to message #46895]

Mon, 16 May 2005 06:35

Eric J
Messages: 71
Registered: May 2009

Viscount

As someone who is building a system at the moment with active crosses, its damn difficult to find any power amp with left than 50 watts per channel unless you buy Vellum and build them yourself.

So if you put in horns, its over kill. I'm currently leaning to using Fostex 100HT's in my new system, andf the smallest power amp I could find to power the tweets is 34 watts RMS per channel. Luckily with an active system I can turn the gain on the crossover way down to at least get the amp out of that bad power range below 1 watt.

You will need to do that. Many amps cannot run adequately below 1 watt without serious distortion. Of course use a tube amp, you may actually like the qualities of its distortion. I'm using transister amps purchased from ebay.

Eric J.

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Why Independent? [message #46904 is a reply to message #46898]

Mon, 16 May 2005 09:16

GarMan
Messages: 960
Registered: May 2009

Illuminati (2nd Degree)

Hi Wayne,

Can you explain why it would be better if crossover frequency can be set independently for LF and HF? Wouldn't Low-pass and High-pass use the same frequency?

gar.

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Some examples [message #46906 is a reply to message #46903]

Mon, 16 May 2005 15:04

spkrman57
Messages: 522
Registered: May 2009

Illuminati (1st Degree)

NOrh SE-9 Single ended EL34 pentode for 9 WPC
Almorro A205 6BQ5 Single ended 6BQ5 5 WPC
Yamamoto 45 Single ended triode 2 WPC

Just to name a few, these are very good amps with horns, I use them to power the entire system though.

For more power, try the Cayin push-pull EL34 for 35 WPC

Ron

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I stand on my statement [message #46907 is a reply to message #46906]

Mon, 16 May 2005 15:36

Eric J
Messages: 71
Registered: May 2009

Viscount

A cursory perusal through google gave me no idication of where I might locate one of these exotic little beasts except for the NOrh SE-9 which I found for $400(and you have to like tubes, which I don't), which obliterates 2/3 of what I need to spend on my DIY speaker upgrade to Electronic crossovers.

Appreciate the thought though. Sort of out of the question for those of us who have other things to buy such as shoes for the kids, or books for their fall semester, and don't have huge salaries.

But just wondering, where would I find one? Certainly not on ebay.

eric j

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Chip amp [message #46908 is a reply to message #46907]

Mon, 16 May 2005 17:00

colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas

Illuminati (3rd Degree)

Eric, Have you looked at the chip amps. They are getting quite rave reviews (see below for one) They list for $39 but can be picked up for $20-25. You could bi-amp your system for around $100. There are also tons of mods on the net that really do make this a "giant killer."

I had the pleasure of listening to Ron's Norh last Friday. For $400 this is a nice tube. I have a Cayin TA-30 that was a steal at $550, but I don't think it's available anymore.....Colin

http://www.6moons.com/audioreviews/sonicimpact/t.html

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Re: Why Independent? [message #46911 is a reply to message #46904]

Mon, 16 May 2005 19:11

Wayne Parham
Messages: 18787
Registered: January 2001

Illuminati (33rd Degree)

Sometimes the best summing comes from an asymmetrical crossover having different slopes and crossover points. This is often the case when the drivers themselves have very different positions and characteristics, as most are. In the passive π crossover circuit, slopes are asymmetrical and tweeter response is shifted by the inclusion of components R1 and R2, moving its crossover point and overall response. But frequency and slope are fixed by the components chosen. With an active crossover, it is nice to have some flexibility.

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Re: Chip amp [message #46917 is a reply to message #46908]

Tue, 17 May 2005 15:01

Eric J
Messages: 71
Registered: May 2009

Viscount

Colin,

How much additional is the power supply?

Actually you can pick up a couple of good power amps on ebay for maybe 60 bucks USD.

But actually there are lots more expenses, as you know if you have done it. You need a preamp if you are currently using a receiver. You need to buy new speakers if you don't know what the frequency response curve of the ones you have are. You need to purchase an appropriate 24 db slope linkwitz Riley crossover device. You need a separate crossover for the sub if you have one. Finally you need a condenser mic and preamp and RTA program for your laptop, or at least a radio shack sound level meter to balance the different speakers and amps.

its a lot of fun but you have to gear up for it.

Eric J.

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