More FRFR...is it harmful to use an 8ohm speaker long term?

Yes, the Catalyst 100 is a wonderful thing - but I think we all like such amps for the variety and, when it comes to variety - well, more is more!

I'm getting into IRs, but despite having good KRKs on my desk, I'm not feeling the warmth.

So, as an experiment, I want to try Celestion's FRLR speaker (the F12M-150) in my Cat. The reasoning here is that the speaker is nice and flat for IR's, but also physically behaves like a guitar speaker (LR stands for "live response").

The F12M-150 is however 8ohm. 

There are lots of references on the InterWeb to replacing 4ohm with 8ohm that suggest it is completely safe, but the output is cut. This isn't an issue in my home studio (definitely not my bedroom). My concern is - one guy at a music store that stocks the speakers replied to an email and said that doing the swap would cause damage to the Cat in the long-term. It's a single differing opinion, but now I'm wondering if I'm risking my amp! I could understand the logic if it were a valve amp, but it isn't.

I would appreciate any advice (esp. from rd2rk, coz I love your acronyms ;) )

IIRC, the Cat's amp is a standard ICE module. Probably not a high-end one.

Using an 8ohm speaker probably won't damage it.

Probably.

Why not ask L6 support? They'd know better than some rando internet guitar geek with a cool handle ;-P

FWIW - I once tried a whizzer cone speaker - it sounded like a weird guitar speaker with a lisp. IMO, YMMV etc.

Like little cryptic nuggets...thanks for your reply!

I asked Line 6 for advice and got this:

"Thanks for reaching out. This has not been vetted or tested by our engineers, so we can't comment on any modifications, I'm afraid. Swap speakers at your own risk. All the best, Hodgy Customer Support Team Yamaha Guitar Group"

So, they sell amps with an uncommon speaker impedance that are designed to be a compromise. No frequency curves available. When purchasers wonder if they can get a bit more out of the amp and try an extremely common thing - changing speakers - the entire Tech Dept has never come across such a thing!

The overwhelming results on the web for the change is "decreased output but harmless", so I'm going with that.

One of the reasons for the change is I spent money on another Line 6 product (Helix Native) that has lots of wonderful cabs, includes the Cat amps, and lets me play with top tier IR's. If the speaker works as claimed, then I get the entire Catalyst collection plus everything else in the known guitar universe. 

More Is More (or MIM...)

Actually, that is a very common speaker impedance for MODELING amps.

It's NOT common for straight-up guitar amps where speaker changes are common.

The Catalyst was never intended to be an FRFR amp.

It is what it is advertised as and if that suits your purpose, great.

My recommendation is to buy an amp that's intended for your purpose.

Blackstar has a new FRFR amp that has a whizzer. Check it out.

Fender, Laney and IK Multimedia also have FRFR cabs.

Of course, they all cost at least twice what the Catalyst costs and are closed back cabs.

I wonder why that is? Hmmm....

Good Luck on your whizzer adventure!

I received a direct reply from Celstion - they confirmed that I would get a drop in output, but a solid state amp won't be damaged by using an 8 ohm speaker. 

I'm hoping to get the speaker soon - if guitar sounds better through a 1 x 12" cab than my KRK's then I'll consider that a win!

Nothing against the Cat speaker - it's just that it's ONE speaker, whereas all the goodies in Helix Native and Guitar Rig 7 come with their own (and I've started my York Audio IR collection). The Cat amps can be found in Helix (I notice that none of them are matched with the stock speaker) so it's not like I'm losing anything.