A crossover question (1 Viewer)

[Roman Ortega]

Hello to every one in this forum, since last December these are the components of my home theater:


Receiver: Pioneer VSX-D710S
Speakers: Sony: SAVE-325
Subwoofer: Sony SAWM40
DVD Player: Panasonic DVD-RV30
And a 4:3 CRT 29” Samsung tv

I have the main speakers connected to the level input of de SAVE´s subwoofer and from there to my front left and right output of my receiver, the wm40 is connected by the subwoofer pre out of the 710 and all my speakers are set as small.

Well this is my problem, I have recently downloaded the NCH tone generator to make some test on my subwoofer (Just wanted to know if there was any frequency disappearing because I doesn’t have an spl meter yet) and see how the crossover was working, so I connected my computer to an analogical A/V input and run my tests from there, the tests for the subwoofer were fine, all the frequencies were present but not at the same level and after a while I find why, the crossover wasn’t working at all, it doesn’t matter what was the value of the crossover, the tones were always in the wma40 and in the front speakers. After that I connected the main speakers to the level inputs of the wma40, configure them as large, and turned off the subwoofer in the receiver setup, I run the tones again but playing with the sub crossover and this time it works in the opposite way, the tones disappeared from the sub but not from the speakers, I don’t know what is happening, Does my receiver has a problem with the crossover or there is something that I made wrong?, Why is the sub crossover letting frequencies go to the speakers?, can you also recommend me which of the two speakers arrangements that I have described will work better. I will appreciate any help you could give me thanks.

 

[Roman Ortega]

Come on somebody I don’t think it’s a foolish question and its really tearing my sleep away

P.S. sorry to those who have read my "this are" mistake, Take in count that I think in Spanish and English is not my "every day language" so I make this mistakes more often that I like, anyway I promise to do my best to improve my self:b

 

[Greg*go]

If you just want to use the receivers crossover, just plug the l/r speakers into the the l/r outputs of the receiver. Since you have them plugged into the sub right now, it's hard to determine wether it's the sub's crossover or receiver's crossover that's giving you problems. Once you put the speakers directly into the receiver, set them to small, which should also automatically turn the subwoofer output on (if it's off). If you try your test tones again, you should get better results.

 

[Greg*go]

sorry to those who have read my "this are" mistake

Don't worry about it Roman, I wish I could speak another language as well as you.

 

[Cees Alons]

"This are" isn't a problem to us, but requesting an answer within a day is. Please don't do this again - give members some time (1) to awake if on another continent, (2) think your problem over and then (3) allow someone who thinks he/she knows what's going on in your HT to formulate an answer.

The problem you're posing is this: it shouldn't work that way, so everyone who wants to help you is thinking hard what can be going on.

Are you really sure the lower frequencies were still coming (with the same strength!) from your "small" speakers? What was the setting of your receiver: Dolby Pro-Logic (I can't think of any other setting to work from an analogue signal)? I suppose you had a sub setting in your receiver set to "sub present", whatever it is called?

These questions arise from the fact that we don't understand - not because we think you don't know what you're doing.

Cees

 

[Roman Ortega]

Thanks a lot Greg you really take me out of my trouble, I think I have already figured out what was going on. Since the sub that I was connecting to my speakers is an active one, and the crossover’s cutoff frequencies are not absolute but just a reference number (I’ve heard that in the simple filters is the point where the signal has the 0.7% of its original value) the signals that were supposed to be barely audible were amplified by the sub, making the impression that the crossover wasn’t working.

Any way, I’ve found the “Fall Time” off the crossover very coarse and its throwing frequencies from 100 to 150 Hz to the subwoofer (at the receiver’s minimum crossover frequencies that is 100Hz) so I’ve been thinking in adjusting it whit my sub’s crossover but, Do you think that it will means that I loose some information in the LFE channel?

Again Thanks a lot To Greg and to any one who can answer my questions

P.S. Sorry for the rush but I made this same post in the speakers forum three days ago and there was no answer so I was expecting the same here, for me it wasn’t a day they were four, But sorry anyway

 

[Greg*go]

If the subs crossover is 100Hz, and it's receivng stuff up to 150Hz, then your speakers should also be receiving the stuff between 100-150. Manually turn off your sub's amplifier and give the test to see how low of a frequency your speakers go. It should go a little lower then 100Hz (it might go a lot lower, but the volume of the sound should greatly diminish making it a non-factor). So when you turn your sub back on, and you adjust the crossover on the sub to 100Hz, my guess would be that you shouldn't lose any info. Since your speakers are outputing that info as well.

Some sound is going to leak past the crossover both ways, but it shouldn't be significant. Is the sub giving an output at 150Hz that is equally as loud at 50Hz? If that's the case, then your receiver doesn't have a very good crossover in it.

Plus as Cees said, since you have an analog connection, you will only be able to get Dolby Pro-logic. So all these tests you are doing won't really help you set up your Dolby Digital for movie watching. They're more along the lines of general interest since a DD connection through a digital cable will have a different result. Anyway, hope this makes sense and helps.