Anyone know the crossover for Ultra 5.1s? Or the ohms

[nightcabbage]

Alright, so after reading through these two threads: http://forums.klipsch.com/forums/p/131464/1334739.aspx http://community.klipsch.com/forums/t/127610.aspx , I'm fairly certain I'll be purchasing a new plate amp and a receiver to bring my ProMedia 5.1 Ultras back to life. A few questions remain though:

#1) CROSSOVER: The old amp in the back of the Ultra's sub did crossover... but does anyone actually know what it was set at? I mean, not a guess... does anyone really know? Since I'm going to have to set the crossover manually now on my X-Fi sound card (I'm doing multi-channel in on my receiver because I want my X-Fi doing all the work for various reasons), I would like to match it up perfectly with what the system was set at before.

#2) PLATE AMP RANGE: Also, user nashbridges (which posted in both of the above threads) used this 300W BASH plate amp for his sub: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-750 . The only problem I see in that is that the plate amp's low end is 50Hz, but in the Ultra's spec page: http://www.klipsch.com/na-en/products/promedia-ultra-5-1-specifications/ it shows that the entire system's low end goes all the way down to 25Hz. Does that mean if I use this 300W BASH plate amp, I'll loose that 25Hz on the low end that I had before my system crapped out?

#3) OHMS/RECEIVER?: Does anyone know the ohms impedance for the Ultra 5.1 satellites, center channel, and sub? (I thought I saw somewhere on these forums someone said they thought they were 6 ohms, but how do they know for sure?) I need to know so I get a receiver that will match it right? I know next to nothing about ohms impedance and what that means or how it will effect which receiver I choose to power the satellites. Any help there would be appreciated. Basically I've heard that if you have a receiver that has 8 ohms output, you want your speakers to match. I heard if your speakers' ohms impedance are below the receiver's range that is bad? If they are a bit above it, no big deal?

[nightcabbage]

Well, I think I answered my own question for #2. The 50Hz is the lowest the CROSSOVER can do on that BASH amp, not the lowest it puts out. There's a filter that will drop off at around 17Hz - 18Hz on that BASH amp. So no, I wouldn't lose the extra 25Hz that the dual 8" Ultra sub can do. Woohoo! (Though I'm now wondering if that BASH amp will be sending too low of a frequency to the sub drivers... I don't want to damage them! Meh, maybe 8Hz lower isn't that big of a deal?) I'm also unsure of how ohms works for subs/sub amps. Did you need to do any matching there nash?

If anyone has any more info on that I'd love to hear it though. I really need to figure out #1 and #3 now...

[nashbridges]

Me again. They are 6-8 Ohms for the satellites, at least from this site: http://www.pcabusers.com/klipsch/klipsch.html. The back of the original Ultra amp was stamped with "4 Ohms minimum" on the satellite jack section. Most home receivers are rated for 8 ohms, but you can get by with 6 ohm speakers if you don't push it. Here's a decent article on it:

http://www.hometoys.com/htinews/feb04/articles/polk/impedence.htm

I was worried about it before I bought the amp and receiver, but the general advice of not running everything at full power seems to be pretty good advice. The side effect of running lower ohm speakers against a too powerful amp is overheating of the amp (sound familiar?), so make sure your receiver has some room to breathe. I thought my cheap *** Sony receiver would overheat at loud volumes because the Klipsch satellites were closer to the 6 ohm end of the range but its been fine, even at loud volumes. If you are going to run your system at 100% all the time, then there probably isn't a home receiver out there that will work well with the Ultra 5.1 satellites.

Still, I'm chilling listening to iTunes from the last test I posted in the other thread, and the speakers are working fine. My Sony receiver specifies "nominal 8ohm impedance" for satellite speakers. The Klipsch satellites fall into that range.

[nashbridges]

#1) CROSSOVER:

If Klipsch is to be believed, then this should give you your answer:

http://www.klipsch.com/na-en/products/promedia-ultra-5-1-specifications/

Looks like low frequency was set at 120 Hz, I think.

[nightcabbage]

Me again. They are 6-8 Ohms for the satellites, at least from this site: http://www.pcabusers.com/klipsch/klipsch.html. The back of the original Ultra amp was stamped with "4 Ohms minimum" on the satellite jack section. Most home receivers are rated for 8 ohms, but you can get by with 6 ohm speakers if you don't push it. Here's a decent article on it:

http://www.hometoys.com/htinews/feb04/articles/polk/impedence.htm

I was worried about it before I bought the amp and receiver, but the general advice of not running everything at full power seems to be pretty good advice. The side effect of running lower ohm speakers against a too powerful amp is overheating of the amp (sound familiar?), so make sure your receiver has some room to breathe. I thought my cheap *** Sony receiver would overheat at loud volumes because the Klipsch satellites were closer to the 6 ohm end of the range but its been fine, even at loud volumes. If you are going to run your system at 100% all the time, then there probably isn't a home receiver out there that will work well with the Ultra 5.1 satellites.

Still, I'm chilling listening to iTunes from the last test I posted in the other thread, and the speakers are working fine. My Sony receiver specifies "nominal 8ohm impedance" for satellite speakers. The Klipsch satellites fall into that range.

Hmm... that third party page is listing specs for the original ProMedia 5.1s, not the Ultras. They COULD be the same specs, but I'm not sure I trust them. Dang I wish I could find a reliable source somehow!

Can speakers have ohm "ranges" (like some receivers) or are they a specific ohm number? I don't get the 6-8 ohms, as most other speakers I've seen just have one number. Either way, it is probably better to hook up higher ohm speakers to a lower ohm receiver than the other way around (though I understand your suggestion of just keeping the volume down to prevent problems)? Given all that, I think I may go with this cheap 6 ohm receiver with multi-channel in:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=252-107&FTR=Sherwood%20RD-6513&CFID=24465151&CFTOKEN=14647453

I'm still wondering about the ohms for the combination of those two subs... but I think that BASH 300W is 4ohm, so it will probably be ok. I doubt a pair of subs will be below that (or if it is even possible). They are probably somewhere between 4 and 8. Well, YOU'VE been using it nash and nothing bad has happened, so maybe that is proof enough right there

#1) CROSSOVER:

If Klipsch is to be believed, then this should give you your answer:

http://www.klipsch.com/na-en/products/promedia-ultra-5-1-specifications/

Looks like low frequency was set at 120 Hz, I think.

Hmmm, I saw that and wondered if that "LF" 120Hz was indeed the crossover from sub/satellites, but since the Klipsch guy on the phone told me he thought it was 100Hz I got confused. 120Hz sounds more plausible given the size of the satellites though. I guess that's what I'll set my crossover to then!

[nashbridges]

Can speakers have ohm "ranges" (like some receivers) or are they a specific ohm number?

That article I linked to explains that speaker resistance varies with the frequency, so the number they give is usually the average over the normal range of frequencies. That's why you can get away with using lower rated speakers on an 8ohm receiver. Everything I read before I bought the receiver indicated that the problem with using speakers with a low ohm rating (low resistance) is that your amp in the receiver might have to work too hard at higher volumes, which can lead to burnout of the amp.

I just cranked up the new sub to see how loud I could get it but I quit around 60% just because it was too loud. I think if I maxed it out I might blow the speakers in the sub, but I'm not sure the maximum amount of power the original amp sent to the sub. If it reserved 60 watts each for the sats, then that would leave 200 watts left over for the sub.

Really, the biggest trick in all of this has been fine tuning the receiver. Klipsch did a great job with the original amp (design flaws notwithstanding) because the system always sounded great with minimal fuss. It's been a lot of work to get it sounding like it used to, and I 've found that I usually like to bump up the volume knob on the new plate amp when I'm playing computer games just for more "thump-thump". For regular TV watching, I like to keep it scaled back a little bit.

And on the crossover - I had my receiver set at 140 Hz until I found that link, then I bumped it back down to 120 Hz. It did sound better, at least as far as TV was concerned. Voices sounded more natural.

[nightcabbage]

Well, someone else at Klipsch confirmed that they thought the crossover in the Ultra's amp was probably 120Hz and not 100Hz, which makes sense given the size of the satellites really. I think that meshes with the specs page for the Ultras anyway, as I'm almost sure that's what the LF was.

This same person at Klipsch said the Ultra's satellites were 8 ohms. The receiver I'm getting (http://www.newegg.com/Product/Product.aspx?Item=N82E16882115193) can switch between 8 and 6 though, so I'll be good either way. Weird that the speaker outs on the back of the Ultra amp said minimum 4 ohms though... why provide such low support when you know your sats are 8?

He had no idea about the ohms for the sub, but since the two woofers are wired in series, I doubt it will be BELOW 4 (speakers wired in series add their individual ohm numbers together, so two 4 ohm woofers wired in series has a total of 8 ohms). So if anything, it might be all the way up to 8. I'll probably only get a bit over 150W out of that BASH amp if that is true, but I'm sure that's enough. My main concern was going under and hurting something.

I'll be getting everything soon except the BASH amp, which is on backorder at Parts express until the beginning of April. I'll let you know how it goes. I'm excited!