How to ease into this

[dacodo]

Just out of curiosity..... for those of you that run an HT setup with a center channel....

How do you amp the 4-ohm center? (since so many receivers are underpowered to run 4-ohm speakers, and most designed here are 4-ohm)

Does your receiver power it? Do you run a monoblock (like: AudioSource 5.1A monoblock). Or do you just use a stereo amp? or some other method I don't know about?

Just thinking and planing down the road (so I keep an eye out for deals).

[Blktre]

Does your receiver have preouts? If so, you can buy a multi channel amp and run all your speakers off the amp and not worry about it. Your receiver will become a pre/pro then. The cool thing about that is you can be on your way to running quality seperates, if a serious HT is in your plan. Outlaw and Emotiva carry some budget/hi performance 5-7 channel amps.

[Geoff Gunnell]

Dacodo, what receiver do you have? What speakers?

Many (most?) receivers may not have the internal power supplies to push the same RMS watts to 5 or more 4 ohm speakers simultaneously as to just a stereo pair, but this is often a moot point in actual practice unless you have a combination of small receiver, large room, and/or very inefficient speakers.

This is not to say adding an external power amp might not sound better; however, (and I'm obviously shooting in the dark here since I don't know what equipment you have), if your current receiver won't drive a 4 ohm load you might get more out of an upgrade to a current model receiver that will.

[dacodo]

sorry. it was mostly just a curiosity question on how most of you did your stuff.

Just doing research. and lot's of "what if's" for the future.

I have a 5.1 receiver (a cheap Pioneer Multi-Channel Receiver VSX-D412S that I only have $30 invested in), and it has no preouts. I may consider that a $30 learning burn. (maybe I'll drive some outdoor speakers with it)

I'm looking at building a pair of Curt's Triune or TriTrix and a sub to start a 2.1 system, then add a center channel later (and eventually 2 rears when we move in 2 years).

I'm mostly trying to ease into this and trying to future proof myself as much a possible as I get into this. I don't really have any firm plans right now.

Just learning and plotting.

[mlamp]

i would second the suggestion of making sure to get a receiver with pre-outs. i bought a used outlaw 1050 that had them, and one of the amplifier channels started flaking out. instead of spending money replacing the entire receiver, i found an adcom 5 channel amp on ebay for what that would have cost me. major upgrade in sound quality, 4 ohm stable, great amp. now if i ever need to replace the outlaw, i'm just buying a pre-pro, not an entire receiver again. much more flexible, and a great way to ease into separates, or use an HTPC as a preamp if you want to go that route in the future.

[dacodo]

I have a media center PC also (with 2 SD tuners), and at this point that would be my only source of multi channel audio (SD DVD's), but will probably pick up a PS3 in the future for blue ray.

We are getting our first HDTV in a few weeks.

Any suggestions on a pre/pro to took at? I would like to stay sub $200 if possible. (and I'm not afraid of ebay/used).

You would think that by removing the amp from the receiver it would be more inexpensive... but somehow I'm guessing that is not going to be the case.

Or should I just hunt for a used /refurbish receiver with preouts, then upgrade that once I start dealing with more HD and surround sources?

HK sells their referbs on ebay so picking up a HK AVR 247 (has preouts) for $100-150 shouldn't be that much trouble.
-nik

[dacodo]

Ok all of you feel free to laugh at me on this one. What would building something like this do? (hey I'm just trying to learn at this point.)

http://www.epanorama.net/circuits/speaker_to_line.html

Or would that just create an utter disaster of a signal? I'm guessing any crap created by the HT amp would then get amped again going into a 2ch amp.

In theory couldn't you just run your HT amp at really low volume and accomplish the same thing?

Solder surface mount components I can do... Build computer from components I've been doing since I was 16.... Digital & basic voltage stuff I understand. (I'm typing this on a heavily modded EEE PC right now - EEE Modding)

This analog stuff just confuses me though. Sorry, trying my best to wrap my head around it.

[Gir]

All it's doing is knocking down the speaker level voltage to a line level voltage. I've seen this used a few times in car audio since it's hard to get the line level sometimes. You'll probably want a 1/2W for the extra safety margin, but 1/4W should work.

[EDIT]
Going through the math, if you have a 100W amp going into a 4 Ohm load, then that amp can output 20V (P=V*V/R). Now looking at your proposed modification, assuming you have very little current flowing into your new power amp since they're a fairly high impedance (read negligible because I'm lazy), you roughly have 20V going across 11k Ohm. This leaves you with about 1.82mA. Now just looking at the drop across the 10k resistor, which is dissipating the most power, we can use P=I*I*R, which gives us 33.1mW. 1/4W is 250mW, so it's perfectly safe to use that. Hope this helps you understand a bit.

[dacodo]

Yea thanks. I'm still looking into the pre/pro thing if anyone has any recommendations.

But I think I'll go ahead and order the parts for the Triune's so this whole ohm thing doesn't hold me up. (I picked up a behringer a500 today for $140 as a starter amp for my fronts).

I'll work in stereo for a bit and just enjoy the build. I have some bamboo laying around that is dieing for a woodworking project.

(of course that's all after I polyurethane my floors this weekend, thank God this 1.5 year home renovation project is winding down.)

[ThomasW]

But I think I'll go ahead and order the parts for the Triune's so this whole ohm thing doesn't hold me up.

Might want to spend the extra cash and build the TriTrix

[dacodo]

Isn't the Triune '07s the slightly better design? or are the 8ohm TriTrix better? I really have no preference. Just assumed the newer Triune '07s were the better design.

I'm definitely getting a receiver that can preout or a pre/pro at some point in the next little bit. Just trying to get started soon without dumping a couple grand on to. I tend to like to build slowly.

My plans now are 2.1 to 3.1 to 5.1. Build and upgrade as I go.

But really I'll build either set. I just assumed the newer design was the better to go with. But please let me know if I'm incorrect!!! I'll do whichever (both seem pretty strait forward and in my budget).