Z-5500 Speaker Swap

[Uninvited Guest]

It says not to swap the speaker- right on the product. But ever since I purchased the set (for $250 new) I've really been missing the sound I got from my 2.0 bookshelf speaker setup I had from before. The speakers aren't fantastic - they're taken from a SHARP stereo set. But they work well, having 6" drivers and something inch tweeters, much better that the Z-5500's satellites.

So I'm looking to swap out my speakers, and looking to avoid any pitfalls when I do so. Is there anything major I should consider, besides impedance? I have 4 sets of bookshelf speakers rated at 8 ohms, matching the logitech impedance. I have a 3 way 6X9 Car speaker which I'm probably going to use for centre- but I need to look up its impedance. Hooking all of these up, I don't forsee any problems.

But I also have access to gigantic and ancient Bose 501 redirectional floor speakers. You can find the owner's manual here.. An exerpt from the specifications as follows:

The impedance of the Model 501 speaker system is conservatively rated at 4 ohms. However, since the impedance of the Model 501 is substantially above 4 ohms over all but a small portion of the frequency range, high quality receivers can operate an additional pair of 8-ohm speakers or a second pair of 501's (connected in parallel) with no difficulty.

I'm wondering- can the z-5500 amp handle this? Thanks in advance.

 

[Slick5150]

I had some 4ohms Klipsch GMX speakers hooked up to a Z-5500 system for awhile and it didn't have a problem. But YMMV on that I suppose. Just keep an eye on the heat coming from the amp if you try this.

As for the 8ohms speakers, it would work fine. The only problem is that the Logitech system has a fixed crossover, which is pretty high (I think its around 140Mhz), so the speakers aren't going to extend as low as they probably can. This leaves the Logitech sub doing some of the midrange which hurts the quality. This is ulimately why I scrapped the whole thing and bought a new receiver and subwoofer.

 

[Uninvited Guest]

Thanks for the quick reply.

Would there be anyway to adjust the crossover frequency on the amp? Whether it's set in the receiver or the sub, and what alterations would need to be done?

Or is there a way to bypass it with software. I use the 6 CH direct, so is there anyway to set the crossover on my computer and bypass the signal splitting done by the receiver? (A stretch, I know, and I'm also not too knowledgeable about this, I'm sure it shows.)

 

[YOyoYOhowsDAjello]

140Mhz is rather high for a crossover

The crossover frequency is fixed on the Logitech set at what I think is about 120Hz.

I don't think there's any way around that using the logitech sub to amplify the speakers.

Something else to consider is the sensitivity of all your speakers. Even if they're all able to be driven by the amp, that's not going to prevent issues of level matching. Does your soundcard / integrated sound have the ability to adjust the levels of each speaker independently?

 

[Uninvited Guest]

The z-5500 receiver can control individual volume levels for frot, side, and centre/sub. I believe my motherboard can do the same- it uses the realtek HD audio driver.

 

[YOyoYOhowsDAjello]

Good, you should be able to compensate for any volume differences between speakers due to sensitivity and distance then.

I've hooked up 8ohm bookshelf speakers to the z-560 sub in the past without issue.

Another issue would be the timbre matching of these speakers. They're probably all going to sound really different from one another which is one of the disadvantages of having a mixed setup like this.

With the 501's it would be nice to know where that drop in impedence takes place over the frequency range to see if it's even going to be an issue for you at all. Probably not a big deal.

 

[Uninvited Guest]

Perfect, well as long as I shouldn't be expectng explosions, then I'm happy.

I suppose I'll start another thread about z-5500 crossover adjustment/hacking.

 

[YOyoYOhowsDAjello]

Try googling it first.

 

[Slick5150]

Originally posted by: YOyoYOhowsDAjello
140Mhz is rather high for a crossover

The crossover frequency is fixed on the Logitech set at what I think is about 120Hz.

I don't think there's any way around that using the logitech sub to amplify the speakers.

Something else to consider is the sensitivity of all your speakers. Even if they're all able to be driven by the amp, that's not going to prevent issues of level matching. Does your soundcard / integrated sound have the ability to adjust the levels of each speaker independently?

Woops. Mhz, Hz, what's the difference

But actually, I think it is higher than 120Hz. I assumed it was around there too, but upon doing some searching some people had tested it and it was cutting off closer to 140Hz. I'll dig around and see if I can find that.

 

[YOyoYOhowsDAjello]

Yeah, I've seen reviews say anywhere between 120Hz and 200Hz.

I've never really played with a set beyond checking out one of the BB type displays so I have no personal experience with it.

Whatever it ends up being (which indeed is probably in the 140Hz range), it's going to be higher than you'd like for decent speakers you're using.

 

[alcoholbob]

Logitech subs have a 150hz crossover due to the small size of the satellites. I can't say for the Z-Cinema though, but reviewers have complained about midbass leaking into the sub, it's possible they didn't change it at all.

In the old days Logitech speakers crossed over at 180hz, it was mortifying.