Help with speaker cable recommendations please

@grm I understand that you have some improvements in sound you'd like for your system. How have you concluded that the speaker cable alone is responsible for the shortcomings and a different set is the solution? The purpose of a cable ideally wouldn't be tone control or equalizer, any flaws in the system are most likely due to components, transducers and room acoustics, not caused by the cable per se. Just wanted to caution going down an expensive and time consuming path with limited rewards.

2 suggestions ,
if you can shorten the cable run your choice of used cables go up ,
and the cost go down .
If you like the sound of the AudioQuest cables then stick with them and move up their hierarchy , larger gauge and shorter runs will increase your bass response .

I personally use Cardas cables , have gone from Quad Link up to 
Neutral Reference , I am looking to move up to Golden Reference .

@grm 
what you just described of the Type 4 is a common theme. What you are looking for is exactly where Audio Art Cable excels and in my system the soundstage really opened up as well.  At least read some of the testimonials on his site and see that it sure seems to run in the same vane as what you're looking to accomplish.

I'd move up in AQ to their best copper and gauge that I could afford. You'll definitely find it used. Castle rock is a good example and is a strong move up with no risk of screwing up what you already like. Good luck..

Thanks to all who have responded!
I have tried 4 different speaker cables and did some research, this is what I have learned AND heard.

Gage/AWG, my 15' length of Audioquest type 4 is only 15 AWG, when you begin to turn up the volume to really enjoy the live experience, the sound becomes compressed as if the cable was saturated where it just lost control of the speakers. I tried another $500 set of cables that were around 18 AWG, they sounded sublime at lower levels but suffered the same problem when you turned up the volume. I did learn something with this cable, and that was termination - go nude!! When I dissected the Amp end spade connectors they were soldered to the wire with a large amount of solder, so I cut off the spades, the results were dramatic! My next test was with a very inexpensive cable I purchased from Amazon, $24 for 50 feet of 12 Gage Pure Copper, Oxygen Free, Stranded wire. I connected the wire "Nude) on both the Amp end and Speaker end, WOW, bested the two other wires in terms of detail and ability to go loud without saturating the wire! In fact, I did not need to turn the Amp up nearly as high to get the same output on the speakers! In the end, I went with the last cable in the test, Blue Jeans Cable! I ordered a 30' run of their 10 AWG cable in white and terminated it myself, just stripping the wire and going nude - fantastic! The lessons I learned from this little experiment were this:

1. Price does not necessarily equate to performance
2. For longer runs, the Gage/Resistance of the wire is paramount
3. For terminations, unless they are "Welded" or "screwed" onto copper connectors, you are not getting the best sound out of you cables! Silver Solder still contains a significant amount of LEAD! If your cables are soldered, re-terminate them.
4. Solid wire is not necessarily better than stranded
5. There is a lot of Snake Oil out there, try different stuff if you can before you buy, you may just be surprised with what you can get without spending a small fortune.

I digress - thanks for reading!

grm