Amp / Driver Compatability

[patherb]

Hi All,
I am working on a 2 way sealed bookshelf system with a digital crossover and biamped drivers. The digital crossover is the BSS Audio FDS-366. The drivers I was planning on using are RAAL 70-10D and ScanSpeak 18W/8531G. Both drivers are 8 ohm. I am planning on powering these drivers with a pair of Crown XLS 202 amps. Does anyone see any compatability issues between the drivers and the amps? Thanks in advance.
Jim

[sdclc126]

What sort of compatibility issues would there be - are these tube amps? What is their output?

[patherb]

I'm not sure if there would be any issues. I was looking for some feedback to see if there might be any problems. The amps are rated for 200w per channel at 8 ohms.

http://www.crownaudio.com/amp_htm/xls.htm

[sdclc126]

No problems - a lot of people are using commercial/pro amps these days rather than "hi-fi" amps - seem to get a lot more bang for the buck. Some pro amps may have slightly higher levels of distortion but I doubt they are audible.

You have chosen some very sophisticated and pricey drivers for your project, so I would be more concerned with proper crossover design - your digital XO unit should be fairly sophisticated as well, and have more adjustability than just slope and frequency selection.

[patherb]

The BSS unit is pretty badass. My buddy is a Sound Engineer and highly recommended it.

http://www.bssaudio.com/productpg.php?product_id=6

[patherb]

What's the story with optional Amorphous Core on the RAAL. Is this something I might need?

[Iain McNeill]

You might want to test the noise output of the BSS crossover before you buy. Most pro-audio equipment assumes an auditorium/club environment that is more tolerant of system hiss. I've seen a few pro-audio products (no names to protect the innocent) that use 1Hz bandwidth measurements to get their 100dB+ dynamic range specs when in reality, the full band, A-weighted rms signal to noise is barely 80dB.

You need to do an FFT on all filter channels to see what's really going on.

Haven't tried the BSS unit....yet.

[wakibaki]

This is a curious combination of components. Can I ask what prompted your choice?

w

[patherb]

Originally posted by wakibaki
This is a curious combination of components. Can I ask what prompted your choice?

w

This is a secondary system that I'm putting in my 2BR. I use a Squeezebox as my main audio source as I have all my music ripped to FLAC. I thought this was a good opportunity to try to build a whole system around another squeezebox. I'm probably going to get the digital output and PS modifications done through Bolder Cables. From the squeezebox, I'll be running the coax to an M-Audio CO3 digital converter. This will convert the 75 ohm unbalanced SPDIF signal to 110 ohm balanced AES3. This then goes to the digital input of the BSS Crossover.

The BSS piece comes highly recommended. I also think I'll be able to keep the system noise to a minimum by using balanced connections throughout. My main reason for going to a digital crossover is that my electronics backround is limited. I looked at Behringer DCX2496 and a couple of others. The BSS was apparently the unit that Behringer cloned most of their plans from. The BSS unit just has higher quality innards and more features. For the amps, I was looking for quality while keeping the price contained.

As for the loudspeakers, I'm going two-way and sealed, because this is my first construction project. I also want to keep the bass nice and tight. Since two-way / sealed design is kind of vanilla, I thought I could spice up the project with some ribbon tweeters. RAAL seem to be indestructible, so I figured that was right up my alley. ScanSpeak seem to make high quality, not ridiculously priced drivers too. So that's it in a nutshell. I haven't bought the drivers or the amps yet so the design is still flexible.

[Iain McNeill]

It's not necessarily the quality of the parts. They could have 24-bit converters but if the filter algorithms lack math precision they generate a lot of noise, some of it correlated to the signal which is very bad.

Just saying this cause I did the same thing pretty much with another pro-audio crossover and was disappointed with noise level. My listening room is very quiet though.

Nice speakers though and the set up will kick some serious derriere. I'm running a time aligned tri-amp and it really images nicely.