Advice on a nice stereo setup? - Page 3

Here's my theory (which might be completely inaccurate) about the realistic-sounding vocals (or lack thereof):

 

You will probably notice a dramatic improvement in this area in particular once you get some proper speaker stands. You mentioned that even when you sit on the floor, the midrange still sounds recessed. This is probably because some of the sound is hitting the carpet before it reaches your ears, and therefore some of it is getting absorbed.

 

I had a similar problem with my nearfield setup when I was setting the speakers on my desk, except the sound was getting reflected off the surface of the desk instead of being absorbed. The treble in particular was very sibilant and the bass was slightly distorted. However, once I got my new desk, which has a higher shelf for my monitor and speakers (about 10" above the surface of the desk), I was able to place my speakers at the edge of the shelf. This eliminated nearly all of the reflection problems I was having.

 

Different situation, I know. But I have a feeling this principle is the cause of the flaws in your setup. Don't worry though, you are moving in the right direction! 

For the time being maybe angling the speakers up and directed at a sitting position in the chair with perhaps phone books would help with the reflectance floor cancellation and allow you to sit in the chair which is probably more comfortable than the floor.

Don't worry so much about too much power.  Worry about too little - it's what really damages speakers.  Hard clipping of a transistor amplifier is lethal to tweeters, and if you push an underpowered (for the speakers) amp too hard, it's easy to cause it.

 

More vulnerable speakers often have fuses or protection circuits - the Polks don't.  They're not as easy to damage compared to planar drivers, though.

 

Also, how far the volume knob is turned isn't a good indicator of what percentage of the amplifier's power (well, voltage anyway) is being output.  Receivers and preamps usually have a ton of extra gain so that any particularly quiet (i.e. low voltage) source will be able to get loud enough.  That means when you have a relatively loud (i.e. normal-to-high voltage) line-level signal, you won't have to turn the knob very far to get as loud as you want.

 

As for too much power - well, just don't be stupid.  Play as loud as you want and when you hear audible distortion of any sort, turn it down.  Polk claims the Monitor 10 will handle up to 250 Watts/channel - don't worry about it too much, in other words.

 

Don't worry, the surrounds will almost certainly hold - there's a much stronger internal spider that is actually the primary structural support inside.  My educated guess is that you'll hear distortion from nonlinearities when nearing the extension limits; and audible warning before you go too far.  Anyway, mechanical failure is only one failure mode, and it's relatively unlikely.

 

The other is thermal damage from sustained output - too much power for a long time.  This is when the voice coil gets really hot and melts or deforms in some way - whether it is the coil insulation, adhesive, or former that actually melts.

 

A real danger, however, is an old, cracked or disintegrating surround.  Deteriorating surrounds not only lose the air seal of the speaker, but eventually can't perform their main purpose - ensuring that the cone is centered as it pumps in and out.  If a bad surround isn't replaced, it will eventually cause the voice coil to become mis-aligned and rub against the magnet, ruining the driver.

 

You shouldn't have to worry about this though - the rubber surrounds on your Polks will last a very, very long time.  Foam surrounds however, like those on most Infinity speakers, deteriorate within 25 years or so.  Newer foams are probably better, but most decent new drivers are designed for rubber surrounds now anyway.

 

As for clipping - the reason that it is so dangerous for tweeters is that if you drive your amplifier into clipping on midrange or bass frequencies that the bigger drivers should handle, the clipping actually is made of a whole bunch of higher frequency harmonics that add up to create the square wave.  Those high frequency harmonics can be very powerful, causing the tweeter to overheat very quickly.

 

Remember - worst case scenario, you blow one or two of the drivers.  These drivers are very common and very cheap compared to other vintage speakers - I see an MW6500 driver for $30 in eBay right now.  I'm holding one in my hand, too - a spare for my dad's Monitor 7 - or was it the bad one he replaced?  I can't remember.

 

Compare that to $250 each - minimum - for the EMIM High Energy midrange drivers that go in my Renaissance 90 speakers - and they're rare as hen's teeth, especially in the US.  In fact, I have a saved search on e-Bay set to e-mail me if any ever come up for sale in the US, and I've only ever seen one.  I think it sold for about $300.  There are more in Germany, but often the sellers there (like here) won't ship internationally.

 

Actually, when you say "second ring of rubber", do you mean the inner part that curves opposite of the main curve in the surround?  As I'm playing with the driver I have, I can feel that the stiffness of the spider is actually what is limiting the extension - all the way out, the rubber is still loose.  Inwards, the surround is the limiting factor, but that's at a ridiculous   If you're worried about the surround itself, don't.

Tell us more - check the fuses.  That may be your only problem, although with a smoke smell I'm not hopeful.

 

Was it a tweeter or a woofer?

 

Which receiver were you using?  Did you have the volume maxed out at the stop?  What was your source?

 

If you're playing so loud to blow a driver with a 100 Watt receiver, you're driving it into clipping.  That's the only way you will put enough power through with one of those receivers to cause it to blow.  Clipped waveforms have much higher power density than sine waves - it's all about the area under the curve.

 

If you're worried about your hearing - and playing that loud, I would be - you NEED to get an SPL meter, and you should get earplugs like these.  As loud as you must have been playing, you will damage your hearing over time.  Remember, quality sound isn't about volume.

 

As for assessing your hearing - you can do an initial test with headphones.  That will tell you right away if one ear is more sensitive than the other.  It isn't necessarily damage to your hearing even if there is a difference - wax blockage can have the same result.  That said, there's a good chance there's a channel imbalance in your receiver instead, although attenuation from the sectional is even more likely.

Okay, to me it sounded like you had blown one of your Polks to me.

 

It sounds like you ought to go to an audiologist to have your hearing checked.  Maybe they'll even have you bring your DAP and headphones to see how loud you're listening.

I say, with 1000$ and some free time, start some DIY. 

 

These are highly regarded bookshelf speakers for their clarity

https://sites.google.com/site/undefinition/overnightsensationmtm

 

Design is rather simple, and the parts can all be bought as a kit. Don't be fooled by their size, bookshelves can be as accurate, if not more, than floor standers and rather than spending 300-400$ for prebuilt speakers, you can build and buy these for around 125$. Ask around here if you get stuck.

http://techtalk.parts-express.com/forumdisplay.php?f=2

 

For a bit more of a challange you can try

http://www.parts-express.com/project-gallery/speaker-projects/

 

As for a reciver, Gainclones are regarded highly as speaker amps and for their miniscule price of <100$. You may not get the features of a decdicated reciver but it will destroy and reciver <200$ at doing what an amp should. Power your speakers.

http://www.diyaudioprojects.com/Chip/Beast/

http://www.audiosector.com/lm3875.shtml

http://www.audiosector.com/nigc_kit-users_guide.pdf

 

Add 25$ for material for DIY Speaker stand and ~50$ for high quality DIY speaker cables and spend the rest on upgrading your furnashings, cd/vinyl collection or headphone equipment.