How much Affect do Crossovers Have

[SteveMKentucky 70]

I have just installed a new (to me) pair of Carver Sunfire CRM-2's.  I'm running them with a Polk PSW-111 subwoofer.  Since I'm driving them with a Carver 900 I connected the receiver directly to the sub, then connected the CRM-2's to the outputs of the sub. 

 

My question is, how much affect does passing the signal through the Polk crossover have on the performance of the Carvers? 

[compwaco 1,129]

I wouldn't do that. The CRM-2's are VERY good speakers and filtering their signal through an inexpensive (built to a price point) subwoofer crossover should significantly degrade their performance.

[PMAT 2,061]

Awesome speakers. Try it several ways and pick what you like. I personally don't care for the setup you described.

[danowood 2,167]

I'm kinda with Paul, thats like buying a Ferrari and putting regular gas in it to me....  I would look for another amp to run them seperate....

[SteveMKentucky 70]

That's what I figured.  So how should I hook them up?  No subwoofer output from the 900, so just run them without a sub for now?

[B-Man 4,784]

 

 

I have just installed a new (to me) pair of Carver Sunfire CRM-2's.  I'm running them with a Polk PSW-111 subwoofer.  Since I'm driving them with a Carver 900 I connected the receiver directly to the sub, then connected the CRM-2's to the outputs of the sub. 

 

My question is, how much affect does passing the signal through the Polk crossover have on the performance of the Carvers? 

 

Without looking at a schematic for the crossover, who knows ??  

 

Try this - listen to them, without the sub, on a song you know well.

 

Hook them to the sub, but leave the sub power cord unplugged. Listen to the same song, AT THE SAME VOLUME LEVEL.

 

Does it sound the same ? I would bet it does - I bet the crossover in the Polk has little to no affect on the signal going to the CRM2s.

 

As a matter of fact, it has been discussed, ad nauseum, in some of the AV forums that running in this fashion cleans up bass coherency because of timing issues eliminated by this configuration.

 

It's worth a try and it won't cost you anything to test it out. 

[Daddyjt 9,858]

I'm with Brian - we often forget to try the obvious (and free) solutions...

[SteveMKentucky 70]

...

 

Try this - listen to them, without the sub, on a song you know well.

 

Hook them to the sub, but leave the sub power cord unplugged. Listen to the same song, AT THE SAME VOLUME LEVEL.

 

Does it sound the same ? I would bet it does - I bet the crossover in the Polk has little to no affect on the signal going to the CRM2s.

 

...

 

Should'a thought of that myself.  Will give it a shot tomorrow. 

[kve777 6,904]

Personally I would run the sub off of the pre-outs. Pull the U connectors out and install a pair of Y-connectors with two males and a female.

 

Run Interconnects to the sub L&R inputs. Resist the urge to Y them together and use the LFE port. It will kill your stereo separation for the CRM-2's.

Then just wire the CRM-2's straight from the A speaker jacks.

As an alternative you can run speaker wires from the B speaker terminals right to the sub. Don't forget to engage A+B speaker selection.

Call me if you need to. 

[fill35U 1,848]

Personally I would run the sub off of the pre-outs. (snip)...Then just wire the CRM-2's straight from the A speaker jacks.

 

But that doesn't protect the CRM-2's from being overdriven at low frequency?:

 

 

 

 

Or is that not an issue, since the 900 will audibly clip before thermal or excursion limits of the CRM-2's? Seems like a substantial tradeoff in headroom if you don't use *some* kind of crossover. Maybe also try line-level passive crossovers in the pre-outs loop(after splitting off the sub's signal!) for cheap comparison? At least you'd have more control. 

[SteveMKentucky 70]

(...)    Or is that not an issue, since the 900 will audibly clip before thermal or excursion limits of the CRM-2's? Seems like a substantial tradeoff in headroom if you don't use *some* kind of crossover. Maybe also try line-level passive crossovers in the pre-outs loop(after splitting off the sub's signal!) for cheap comparison? At least you'd have more control. 

 

It does seem to make sense to have some sort of crossover in line between the receiver outputs and the speakers.  That's the main reason I originally connected the sub between the receiver and the CRM-2's.  I expected that the crossover within the sub would perform that function.  I guess the question is whether or not I need a higher quality crossover to take full advantage of these speakers or not.

 

By the way, the Sunfire sub contains such a crossover.  Correct? 

[SteveMKentucky 70]

OK, so I have another question.

 

When I connect the main speakers to a sub that has an internal amplifier, what is driving the main speakers? In other words, does the sub use its amp to drive the sub only and pass the output from the receiver to the main speakers after stripping off the low freqs (via the crossover)? Or, is the amp of the sub used to drive both the amp and the main speakers?

 

As an example, a Carver True Signature sub that I'm looking at advertises a 750 watt amp. What is that amp driving?

[kve777 6,904]

That amp just drives the sub. Your main speakers are still driven by your main amp.

 

[kve777 6,904]

That's what I figured.  So how should I hook them up?  No subwoofer output from the 900, so just run them without a sub for now?

Personally I would run a couple of Y connectors off the preout of the 900 and run one pair to the sub and one pair to a bigger amp like an M-500t or M-4.0t. There are pieces like the DBX Model 120X that's an active sub crossover, essentially.

 

[LVMAN777 358]

"..The Sunfire subwoofer contains such a crossover. Correct?..."

 

A crossover for "line level" inputs and outputs...

 

Not for a power amplifier...