What is a pre-processor?

[Rike255]

Sorry I'm really new to all these technical words, I see this one getting thrown around a lot when referring to A/V receivers. What does it mean/do?

Thanks.

[jayman_1975]

reciever without the amps inside....to be blunt.

[venomclan]

A pre-processor or pre/pro is the "control" unit that an amp/s hook up to. Think of a receiver without an amplifier section, that is a pro/pro. The pre/pro controls everything (volume, video switching, sound formats etc.) while the amp just amplifies the speakers.
Venom

[Rike255]

Oh I see. So when someone says a receiver has a good pre-processor they're talking about things like that then? Makes sense to me thanks guys!

[hockeyboy]

There is pretty much a few ways to go. An AVR by itself (audio video receiver), which typically is less power; use an AVR as a pre-processor adding a power amp using the pre-amp outs from the receiver; or a pre-pro where you buy a pre-processor and an amp and use those together.

There are benefits to all, but the most common probably in this forum is a receiver with an amp.

[Rike255]

Does the Onkyo TX-SR805 have pre-amp outs? That's the receiver I bought. Not that I'll be buying an amp anytime soon I just want to know if I can if I decide to in the future.

[hockeyboy]

That is a very nice receiver so the answer is yes. The pre-outs are on the right side when you are looking at the back, just above the front left speaker jacks.

[crd2002]

rike yes it does

[hockeyboy]

Me and crd posted at the exact same time!

[Rike255]

Oh ya I see them now. Sweet thanks a lot for the help I understand better now.

Why is it better to use the pre-outs and a seperate amp? Something about distributing the load or something? Or does the receiver not do a good job of it?

[mwaarna]

Alot of receivers cannot handle a 4ohm load.

And dedicated amps can handle them much easier.

Also when you cram an amp and a processor into one box, some times manufacturers skim on features, power, or any number of things...

i started off with a avr with pre-outs, and switched to a dedicated pre-amp, and the sound quality jumped up quite a bit.

But then again i went from a cheapy HK 235 to a Onkyo Pro Pre-pro, so it was quite a jump.

[Rike255]

A 4ohm load. That depends on the speakers right? Polk Audio RTi8's are 8ohm speakers right? Or am I understanding this wrong?

[ShinAce]

Correct. An 8 ohm speaker is the standard for home audio and any amp will run them.

4 ohm speakers draw more power from the same amp. That can be an advantage, assuming your amp will handle it.

[steveinaz]

Keep in mind that impedance varies across the frequency spectrum, at some frequencies the impedance can dip very low (2-4 ohms)--depending on the speaker. Better amplifiers handle these swings in impedance much easier.

When manufacturers specify impedance on speakers, it is a "nominal" figure; ie "8 ohm." This is the average impedance of the speaker across it's frequency range--but it can (and does) vary.

[tonyb]

Good point Steve,and wish it was brought up more on those "will this receiver be ok on the LSI speakers " threads.

[Rike255]

Oh ok, so even though the RTi8's are "8 ohm" speakers it's a good idea to have a receiver that can handle 4 ohm or even 2 then.

[tonyb]

No,that was not implied.Get a beefier receiver or an amp.Not too many receivers can do 4 ohm let alone 2 ohm.You can run the rti 8's with a receiver just not a bottom of the line one.