Axiom Home Page Forums General Discussion Technical Questions Can Low Crossover Damage QS8s?

After two great years with my M60s, I finally got clearance for some QS8s, which I ordered today. (They are the consolation x-mas present my wife offered when she learned how much a 42" plasma costs. Good strategy if anyone's seeking one.) I'm also going to get a receiver to replace my Yamaha RV-1105, which was fine but lacks DPLII and can only crossover all settings at 100. I'll be choosing between an HK (435/635/640) and an Onkyo (703 or thereabouts).

So, what I'm wondering, as I ponder the receiver situation, is can you damage the QS8s if you leave them with a crossover below their range, say at 60? I don't think I'll go much lower than 60.

The answer might sway me between an Onkyo and an HK. The ability to set all speakers individually is very enticing on the HKs, but the Onkyos are definitely more affordable, and if I can get by with a 60 crossover on the QS8s, I could get the Onkyo. (I run my M60s on large with no crossover, b/c I don't like using the sub for music.) At some point in the next year I'll be upgrading my center, either with an Ascend 340c or, if Axiom listens to the buzz, a ported Axiom center that goes down past 90. So I know when I reach that point, I'll want to set the center crossover at 60.

Any thoughts or ideas on how the QS8s will do at 60? Theoretically, can you damage them even if they were set to large? Not that I'd do that, but my understanding is that very little bass gets sent to the surround channels anyway.

Austinbirdman

I don't think you would damage them, but you will probably have a huge sonic hole between the speakers lower limit and the sub's upper cutoff frequency. I'd say if you get a receiver with a global crossover, use 80hz. If you have quadruple crossovers, you can set the 8's to 80-90hz and the 60's to 60hz.

No, you won't damage them. If you send a signal lower than the QS8's can reproduce, it simply won't reproduce those lower frequencies. No damage will be done.

I also highly doubt you'll hear any sort of "hole" in the sound. How much below 80Hz data do you really think is being mixed specificly for the surround channels?

I agree with Spiff as far as mixes for the surrounds. Although I wonder about SACD/DVD-A.

I dunno what the numbers really are in practice; but when we all went from Pro Logic to D-D(and DTS) we also went from limited frequency inputs for the surrounds, to full range.

I do know that my M3s out back put out some pretty low stuff when asked to do so.

Check out some other forums; some folks are even using subs in back to augment their surrounds!

......now if Axiom would consider some QS10s with 6.5"s.....

Changing the crossover won't make the QS8's go any lower though.

It's very likely that whatever below 80Hz frequencies that are being sent to the surround channels are also being sent to the mains and center channel as well.

So the cure to any preceived "hole" in the sound isn't a individual cross over, it's a surround speaker capable of reproducing lower frequencies.

Yup,....that's where a nice set of QS10s with 6.5" drivers in a really Big(or ported!)Box could certainly do the trick!!

Thanks for the input. Spiff as always makes sense - but I'm a bit confused as to the crossover on the qs8s. I'll tool around when they come, but shouldn't it be set at 100, since 95 is their low-end cut-off +/-3db?

If that's the case (100), I may have to go with the HK, knowing my goal for a center is 80 or 60 as a crossover.

On the other hand, if I can compromise with 80 all around, the Onkyo will give me more watts per dollar. I'll set the current center, an Energy eXL-C (rated to 60 Hz, which I don't believe), at 80 along with the new QS8s and leave my m60s on large.

Austinbirdman

Thankfully; crossover points don't cause an instantanious mega db per octave fall off.

They fall off gradually enough that you probably won't hear a hole at all if crossing at 80hz.


Besides.....


....that's what most everybody here on the forum crosses their QS8s at anyway!!!

Works for them!!

Austinbirdman,

I have an older Onkyo 601 and it powers my M60's, VP 150 and 3 QS8's just fine. I have all speakers set to small and my dual SVS subs crossed at 80.

I have used Onkyo over the years and have been very pleased with their performance. Although one shouldn't buy on warranty coverage alone, as with most units if they last 30 days without problems they are usually "in it for the long haul" but the Onkyo's have a 2 year warranty whereas the H/K's only have 1 year.

Best of luck with your choice..
Rick