[captainx0r]

All, I'm pretty new to audiophilism, so bear with me.  I'm catching up on a lot of things, but I think I'm still missing some pretty basic stuff.

1. I'm trying to get my head around this impedance thing.  I gather that the common "low end" speakers are generally 8ohm, while some fancy ones are 4ohm and that there's an issue with any particular amps ability to drive one or the other.  Where can I find a good summary of this?  I've read 3 FAQs and scanned the first few pages of this forum thinking it would be covered, but nothing yet.  I bought decent speakers from a poor college audiophile a few years ago, and they're rated(?) at 6ohm.  Where do they fit into the mix?

2. The speakers came with a fancy bi-wire setup, but the spaded ends don't quite fit with my amp.  The speakers have banana recepticals (don't worry, I'm about to use a few more incorrect terms) that unscrew in half, so you can clamp the spade in, or use bananas.  My amp just has the banana ones, and they unscrew, but there's a plastic collar around them presumably to keep stray cable strands in check and away from other terminals.  The problem is the spade won't fit in the little hole in the collar, so I have some ~12ga. copper wire wrapped around the spade (and taped up real good) and inserted into the hole in the collar and screwed down.  Not a great setup - I've been looking for some kind of a spade to banana converter, but I must be looking in the wrong places.  Or is there a better way.  I'm not too into the idea of redoing the connectors on the cables.

3. What's the deal with setting speakers (the output in the amp I guess) to "large" or "small".  This one is tough to search on.

4. I'm building a super low budget HT setup in the living room that already has builtin shelving.  I know heat could be a concern, and I'm considering some of the new digital amps, specifically the Panny sa-xr70 if it ever materializes.  The kitchen is right on the other side of this wall, and the microwave specifically is about 2 ft. from where everything is going to be.   Is this a concern?

5. How extreme is amp modding?  I don't have a good feel for its usage (widespread or not) yet.  Never even heard of it before I found this site. Seems a bit high-endish, but I don't know. If I was impatient and got the xr45 or xr50 I don't think I could handle those wimpy spring clip speaker connectors.

Thanks.

[Tonto Yoder]

1. Speaker impedance is often called "nominal impedance" since the actual impedance may well vary.  Using 6 ohm speakers would be fairly close to using 8 ohm ones; you just don't want some dangerous impedance dip (down to 1 or 2 ohms) that could damage your amplification.

2. Your description of your binding posts confuses me---generally they are "5-way binding posts" on both speaker and amp. If you actually NEED spade to banana adaptors , they're available.

To use this adaptor with a spade, unscrew the gold section that has the black band, slip spade around the shaft just revealed (left of the plastic section in this pic) and tighten it back up. The hole you see in the pic is for people using bare wire.
3. Certain receivers want to "know" how much bass your connected speakers can handle. I have a Panasonic XR-25 with some small JBL in-wall speakers---setting the Panny to "Large" might well overwhelm the 6" woofers.
4. Not sure.
5. Mods can range from simple to extreme. Changing the spring clips would be relatively easy, but you may want to leave extreme mods to those with experience??

Hope this helps

[jqp]

3. "Large and "Small" are frequency output settings for your A/V preamp/processor or A/V receiver. In a typical HT system, "Large" speakers can handle the full frequency range you would get from your 2-channel amp (20-20kHz). "Small" speakers will only be handling say 100-20k Hz.

Allows you to use cheap plastic speakers to handle the higher frequencies while your cheap subwoofer pretends to handle the LFE (low frequency effects).   This is for the "home theater in a box" scenario.

The Small and Large settings do not reflect on speaker quality, they merely allow for the cheaper quality speakers.

In my HT setup I have 5 speakers that are all set to large, because they can handle the full range. I don't yet have Subwoofers, but I still knocked a mirror off the wall (thankfully in a heavy frame onto the carpet)

This leads us to

4. Shelving is very susceptible to vibrations from your speakers, and can even cause a feedback problem for a DVD player when the vibrations vibrate the DVD player. If you have true HT reference levels,  plan on room.modifications

[bubba966]

Large & Small settings for your speakers have nothing to do with what they cost or if they're cheap or not.

You've got a crossover frequency you can set in your receivers menu. So, if you set it to 80Hz or 100Hz or 150Hz etc. and set your speakers to small, the receiver won't send anything below 80Hz (or whatever you've set your crossover frequency to) to your speakers, it'll send the 20Hz-80Hz info to your sub.

If you set your speakers to large, then the full 20Hz-20KHz signal will get sent to your speakers.

So it just depends on what frequency range your speakers were designed to reproduce. If you've got speakers that are full range speakers, set 'em to large. If your speakers aren't designed for full range use, set them to small and adjust the crossover frequency accordingly.

[captainx0r]

Thanks guys.  I think I've got a handle on large vs small.

So I can use my 6ohm speakers (4ohm min.) with a 6-8 ohm receiver and be ok?  If I'm using an 8ohm amp, do I risk damage to the amp or the speakers?  Or something else?

I didn't really explain the binding posts very well.  Here's a clip from the manual on my Yamaha DSP-A780.



You can see the bare wire going into the hole in the collar I was trying to describe.  The spade won't fit in there.  Thanks Tonto for the link - I guess it's simpler/more common peice than I was expecting.

What can I do about the vibrations my equipment will be experiencing in the builtin shelves?  I'm assuming there's some way to help isolate them - what would this concept be called so I can look into it more?  I haven't seen the topic come up (or recognized it) in my research.

Thanks again.

[Tonto Yoder]

So I can use my 6ohm speakers (4ohm min.) with a 6-8 ohm receiver and be ok?  If I'm using an 8ohm amp, do I risk damage to the amp or the speakers?  Or something else?

I didn't really explain the binding posts very well.  Here's a clip from the manual on my Yamaha DSP-A780.
You can see the bare wire going into the hole in the collar I was trying to describe. ...

You don't really have an 8 ohm amp!  You have an amp rated for a certain power level into 8 ohms and another power level into 4 ohms. I would think the 6 ohm speakers would be fine.

Re: binding posts--spades don't go IN the hole generally. There should be some way of getting the spades flat  BETWEEN the two plastic pieces,
tightening the outermost piece to get a metal-to-metal connection underneath the plastic.  
Addendum: I just looked at an older Onkyo receiver and it has similar posts to those on the Yamaha and they DON'T accept spades in the normal fashion: I guess the options are to cut off the spades and use a bare wire connection or to get spade to banana adaptors.

[bubba966]

What can I do about the vibrations my equipment will be experiencing in the builtin shelves? I'm assuming there's some way to help isolate them - what would this concept be called so I can look into it more?

These are great for killing vibrations. Harbie's gear gets talked about around here once in a while if you need to read up on any of it a bit more. But the Herbie's Audio Lab site explains really well what they do.

And yes, your binding posts do not accept spades (those are pretty standard style posts for recivers). You have to either use bananas, Eichmann Bayonets, or bare wire.

[nathanm]

You'll be SOL with spades on those enclosed plastic connectors unless you feel like snipping off one of the sides.  Tonto's connector suggestion would be your best bet if you don't want to put new plugs on.  If you do want to, these are the coolest bananas I've used:


You could ditch the red and black booties and shrink tube 'em and you'll have a super-compact plug that is no bigger than the wire itself.  It's almost like tinning the end with solder, but better.  Unfortunately, not reusable though.