amps for the orion

[amo]

Hi-

Is any one familiar enough with SL's Orion design to comment on what effect one might expect if one used a higher-powered set of amps. He suggests that expensive amps will not add to the sound, and recomends 60 watts per channel times 8 chennels. But I can not help but wander what would happen if 150 watt amps are used... I was looking at the Bryston 5 channel THX. These would probably work great as 2 of them would yeld the needed 8 chennals plus 2 more for a pair of the Thor subs . My thinking is that by using a higher power amp, most "normal" work will be done within the bottom 30% of the amp's output, allowing for lower distortion and strain. I know this is a highly unsientific line of reasoning but I would love to hear some comments anyway.

[tl]

Originally posted by amo
My thinking is that by using a higher power amp, most "normal" work will be done within the bottom 30% of the amp's output, allowing for lower distortion and strain. I know this is a highly unsientific line of reasoning but I would love to hear some comments anyway.

Having an amp with more power than the suggested 60watts/8Ohm will give you:

- up to 5 dB more SPL in the 50...100Hz range
- a higher risk of destroying your speakers

See: Linkwitz on max. dipole SPL

There's no need to worry about the amplifiers linear or non-linear distortion. Any "reasonable" amp will have distortions that are at least two orders of magnitude (factor 100) lower than the speaker's distortion.

Thomas

[pinkmouse]

You should have no problems with the Bryston amps as long as you don't run at silly volumes. What blows up 90% of drivers is amplifiers driven into clipping. Just about every speaker I have is driven by an amp bigger than the speaker is rated for, and I have never lost a driver because of this.

Bigger amps will also give you more headroom for transient peaks.

[Ken L]

Originally posted by pinkmouse
Bigger amps will also give you more headroom for transient peaks.

I am also in agreement with Pinkmouse that driver damage is more likely to occur from driving a SS amp into clipping than from having more power on tap.

My general rule of thumb has been that you're better off overpowered than underpowered - Particularly with SS.

If you listen at reasonable levels the higher headroom usually means cleaner sound.

go for it and let us know how they sound.

regards

Ken L

[amt]

Im eventually going to build a pair myself and contemplated the same power question. But I think SLs' qoute speaks for itself:

"The higher power amplifier has the potential to bottom out and damage the woofers below 40 Hz and to overheat midrange and tweeter at excessive volume levels. The extra volume capability around 40 Hz can only be used with caution. I find that it exceeds what I would use for normal listening to various types of music in my large size living space. For these reasons I consider the AT6012 of Opt 01 a better match for the ORION. "

-which has 60 wpc. I think that the ordinary distortion distroying problem due to low wattage isnt an issue with a woofer used in this dipole situation as is too much power allowing too much excursion. I think its a way of helping you keep your foot off the gas pedal and preserving the drivers. If more volumn is needed, the Phoenix will provide more dbs but apparently with less finese.
But thats just my take. Good luck.


amt

[Ken L]

amt makes some excellent points here.

I would like to state that my comments were meant from a frame of reference of general terms and was not taking special considerations of the Orions into account.

regards

Ken L

[sfdoddsy]

The other advantge of the 6012 is that you can use a channel for each bass driver, making a total of eight channels of amplification, which is what SL recommends.

If you want an alternative 6 channel amp for not much money, a used Parasound 6 channel would be ideal, either 806 or the 1206.

This is especially good if you plan on an Orion variation using a digital crossover as they have volume controls for each channel so you maximise the gain structure for the crossover.

Steve

[amo]

One of the reasons I brought this up is because the individual drivers are all rated substantially higher then 60 watts. One way to look at it, however, is that these ratings are meant as "...in a 3-way system, with passive crossovers, where the entire system shares this much power, not just this driver...". But, if each driver can handle more power then I do not see the point of not using it. I also do not understand tl's comments because I thought more mid and treble can be squized out... From what tl is saying, the entire system would just go out of alignment with a 5 db peak in the 50 to 100 hz range... I guess I just do not understand how amplification really works...

Because there seems to be some interest on the Orion, I have another, more theoretical question: What happens when 2 pairs of the Orion are placed in the same room? This of course would be a large room. First, the two left towers are placed next to each other, and so are the two right ones. If not, then one can be placed close to each corner (3 feet away). This is for situation where precise imaging is not vital, but more volume is required...

Thanks!

[catapult]

What happens when 2 pairs of the Orion are placed in the same room?

I'd put them in the 4 corners of the room (or thereabouts). You could use them for multichannel surround sound at sane volume levels or use the "all channel stereo" mode for loud parties. While you're at it, might as well add a 5th one for a center channel.

[MBK]

Since you do DIY already and you managed to put the X-O together, a chip amp such as SL recommends for the Phoenix offers the cheapest and most versatile solution. See "chip amps:, "gainclones" on this forum.

I did that for my Linkwitz type dipoles, using OPA548. Advantage, you get it so cheap that you get a very decent solution right away and still can experiment with different amps later on.

I do that now, and built an Aleph for my midrange. I find the Aleph more pleasant.

If you build separate PSU's for the chips (recommended, to isolate the effects of different current draws in the different bands) you can even recycle the PSU for any new amp topology that you try downstream. Only the PSU costs real money, the chips sell for dollars, and even an Aleph circuit minus PSU can be built for sub-$20.