Advice needed: Muddy sound

[Shhroomm]

First, hi to everbody!
I got myself a Hartke 4.5xl some time ago. I`m playing it through a Trace Elliot ah350 and a Musicman Sterling. Ok, the sound is really crispy and clear, but here is the tricky part: the sound gets a bit muddy and undefined at moments. So, my decision was to buy another speaker.
I am thinking about ampeg svt 115, to add some bass end,
instead of another hartke. (enough of bright tones)
Questions are: is that a good idea? Is mixing cabinet brands (any) good? Em...what to do?
I thought about another 4.5 or 410, but i think i really need a 15", as the sound is low in bass end and dispersed on concerts. I THINK the head does the job fine, and i`m not considering in its replacement for now.
I would be grateful for every advice or comment.
Simon

 

[smogg]

the trick is trying your set up with different bottoms. try different combinations and brands until you hit on the sweet spot you're looking for

 

[gillento]

In the time I used a hartke 410 XL together with another xl 410.
Before that I used a XL 410 with an XL115, thinking to get a better bottom end.

But I was wrong: the 2nd 410 brought the necessary low end but prevented it from becoming boomy (as with the 115)

 

[Hookus]

A healthy dose of EQ experimentation will solve an equally healthy dose of sound problems. An EQ pedal can be an extremely helpful and handy addition to any rig.