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Thoughts of Pass XA30.5, 60.5

After having read numerous reviews & rave about XA30.5 versus 60.5, some would prefer a 30.5 over the doubling power 60.5, some would have contraditory point of view, believing higher power always having a merits of getting fuller sound, better soundstage or remarkable improvement of overall presentation.
But i just wondering why there is not much or none would like to try bi-amping two 30.5 to feed your speakers?! That maybe the way still processing the sweetness of 30.5, but never overdriven your speaker. Provided you're not using a full-range unit speaker with one pair of terminal on each side. A friend of mine has told me that should yield a unbelievable improvement over the pair of 60.5.
Firstly, your pair of speakers would be driven with more ease since each unit of 30.5 has just need to serve half of your speaker system.
Secondly, it would be more flexible & easy to sell one out if extra power is not needed anymore for getting an easy driven speaker at a later time. Your speaker wouldn't be over driven as well as receiving a bill of less electricity payment too.
More importantly, driving ability would be better than a pair of 60.5, so you could even have more choice of less sensitivity speakers.

But the drawbacks is, your preamp should possess two pairs of output, in addition you need an extra pair of interconnects & speaker cable.

Please share your comments. Thanks!
samhvcc
almarg's avatar
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almarg
9,670 posts
 
One thing to be careful of is the load impedance that would be seen by the preamp. The XA30.5 has an input impedance of 30K balanced and 20K unbalanced. If the preamp were driving two XA30.5 inputs, and if the preamp has two pairs of outputs that are not individually buffered (as is often the case), it would see only 15K balanced or 10K unbalanced, the same as if a y-adapter were used with a single pair of outputs. Many preamps, especially tube preamps, cannot properly drive that low an impedance.

If the preamp provides two pairs of outputs that are individually buffered (as opposed to simply being wired together inside the rear panel), that would not be a concern (although the 30K/20K is still low enough to be a problem for some preamps).

Regards,
-- Al
don_c55
1,025 posts
 
You also need a very, very good Xover such as the Pass XVR1 which costs $4,000.

You are talking an additional $9,500!!!
danielk141
489 posts
 
Don c55,

All the speakers I mentioned do not need an active crossover.
It is an optional luxury.
jafox
1,461 posts
 
Another option would be to look for a non XA series Pass amp for less money than a second XA 30.5, maybe a 150.5 or 250.5 for the lower frequencies and run a XA 30.5 on the top. As much as a crossover may be of benefit, I would try every technique possible to do this with the existing speakers' crossover. Additional active crossover will likely reduce the system's 3D performance, another pair of ICs and a power cord will be required. That's a lot of money.

Ultimately, I think the XA 60.5 would be better performance than all the extra connectivity to biamp.
samhvcc OP
32 posts
 
Thanks all for your input!
I'm not sure about the impedance issue raised by Almarg.
What would the sound become if the impedance drops to 15K balanced or 10K unbalanced? I've no ideas in the technical issues actually.
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