Need help with Logitech Z-2300/Polk monitor setup

[LPM]

Hi all, my first post on the forum...hopefully someone can help me out with this and I'm not in the wrong forum section.

I need a bit of help with a bedroom rig connected to my PC. I am running a Logitech Z-2300 powered sub (with a swapped in 8" JL driver) that is also powering a set of Polk Monitor 30s out of its L and R channels on the rear of the sub.

Sounds way better than when it was powering the stock logitech satellites, but I did notice the crossover is kinda high (150hz or so?) and was wondering if there is a way to run an external crossover like the DBX 223 to clear up the boomy low-mids that are overlapping between the monitors and the sub?

Would running an external crossover override the internal crossover in the sub or no? If so, how would I chain this together to have it work properly?

I am using a GO46 firewire audio interface with a couple different channels of inputs and outputs as well. Not sure if its relevant to the situation.

So, in short...can I run an external crossover and have it work properly? Just want to get the most accurate sound I can out of this setup. Thanks.

 

[BoredSysAdmin]

Ok, few things slightly wrong and a few things very wrong.

Let me get this straight - you are feeding your Semi-DIY Logitech/JL sub with stock amp with low level input from your nice GO46 audio interface and then using high level output from sub ??
This is incorrect and shouldn't be connected this way. Ether user high level output and inputs or low-level inputs&outputs.

Changing woofer,but not the case&amp - well, multiple times it's been said on this forums it's incorrect and very sub-optimal. I'll let someone else like TLS pitch in on the reason Why.

What I suggest to get best possible 2.1 with your equipment is to get HK 3490 AVR (possibly used/refub) - it's one of the few stereo receivers with build-in bass management and dedicated output.

Ask/search around this forum to find right box for you 8" JL driver and build it yourself. You'll also need a separate amp to power the sub.

 

[LPM]

Thanks for the response. All things will be taken into consideration...but like I said, this is a little bedroom setup that in general sounds very clear and big with the exception of the crossover region that is slightly muddy.

The JL sub has the same power handling/ohm rating as the original equipment Tang Band driver and sounds much better in the box than the TB did...not really an issue for me at this point. By the same token, the Polk monitors sound much better than the original sats. I'm not entirely sure how the setup is so wrong if the replaced speakers fall within the power ratings of the original components replaced. (I just know what sounds bad or good to my ears I suppose)

Basically, if I could have some control over the crossover I'd be completely happy (be it the "right" or "wrong" way). If not, I can live with it the way it is.

Thank you for your input though...I do appreciate it.

 

[BoredSysAdmin]

Thanks for the response. All things will be taken into consideration...but like I said, this is a little bedroom setup that in general sounds very clear and big with the exception of the crossover region that is slightly muddy.

The JL sub has the same power handling/ohm rating as the original equipment Tang Band driver and sounds much better in the box than the TB did...not really an issue for me at this point. By the same token, the Polk monitors sound much better than the original sats. I'm not entirely sure how the setup is so wrong if the replaced speakers fall within the power ratings of the original components replaced. (I just know what sounds bad or good to my ears I suppose)

Basically, if I could have some control over the crossover I'd be completely happy (be it the "right" or "wrong" way). If not, I can live with it the way it is.

Thank you for your input though...I do appreciate it.

Well, I was thinking of regular subs. In 2.1 systems like z-2300 you were supposed to plug sats to the sub, however all i'm saying only thing you could do is to add DIY high-pass filter, not perfect solution, but should help.
However if crossover is set at about 150hz then the issue is with your sub playing low-mids then it shouldn't. it can't be fixed unless you add external cross AND amp.

 

[LPM]

Well, I was thinking of regular subs. In 2.1 systems like z-2300 you were supposed to plug sats to the sub, however all i'm saying only thing you could do is to add DIY high-pass filter, not perfect solution, but should help.
However if crossover is set at about 150hz then the issue is with your sub playing low-mids then it shouldn't. it can't be fixed unless you add external cross AND amp.

I see what you're saying. Looks like I'm gonna have to drop some dough if I want this particular setup to really shine (what else is new, right?). Thanks for your time.

 

[skers_54]

You've got a couple things going on. First, the boominess is probably from a peak in the sub's response caused by driver misalignment. You need exact calculations of enclosure volume, port diameter and port length for each specific driver. Unless you get REALLY lucky, the response of the sub is going to be suboptimal with boominess being characteristic.

Second, you won't be able to replace the stock crossover by simply adding an active one. If the stock one is passive, you'll have to build a new one specifically for your speakers/sub. If it's active (which it probably is) there is nothing you can do to change it. In the latter case you can use an external active crossover but you'll also need to buy an amp (like BoredSys stated).

The last thing is more an FYI. Power ratings on speakers are pretty much useless because they don't tell you the conditions under which they were obtained. Plus, power rating and impedance will only tell you if the speaker and/or amp will fail/blow up/etc if used together. They don't tell you anything about the sound quality of the resulting match. Using the Polk speakers isn't a problem (besides the crossover issue) but replacing the sub driver is for the reasons stated above.

The best solution would be to scrap/sell the remnants of the Logitech and build an enclosure for the JL driver. You'd need to get several amps and maybe a crossover if your computer doesn't have that function. Otherwise, the next best solution would be to put the original sub driver back in. The least ideal solution would be to try to equalize the sound to your satisfaction but that's a whole other can of worms. Please remember, the Logitech was designed to work as a system without a good way to upgrade individual components.

 

[LPM]

skers...thanks, I am going to play a little swap game with the 2 drivers and see if anything can be made better in the problem area of the low mids. Even if minimal it may be worth it for me to put the Tang Band sub back in the box (even though its pretty ugly compared to the JL...I'll admit that was the main factor for that particular purchase), heh.