Crossover Settings

[zyepod]

I know this is not a new topic but I'm confused about where the crossover on my reciever (yamaha RX-V650) and my Sub. (Velodyne CHT-10) should be set. Right now the YPAO on my yammie set the the Sub at both L/R and 160. I've got Sub. set at (with 90 being 12:00 postition) 100 or so or about the 1:30 postion. It sounds fine but I was wondering if there can be some fine tuning. Should the Sub, or reciever be set to crossover at the mains lowest frequincy? Or am I totally confused here?

[richinlr]

I am new to this as well. I have a Yamaha HTR-5760 and have been experimenting with several sub settings. What I can tell you is this:

When you set any one of the speakers to small, the low bass from that channel goes to the sub. How much goes to the sub depends on the receiver's (not the sub's) crossover setting. As you set more speakers to small, more bass goes to the sub.

On my setup, changing the center speaker to small (the fronts have always been set to large) resulted in a significant increase in sub out put. The sub output changes very little, if any at all, by changing the surrounds to small. Since my RB-25's (surrounds) go down to 49 Hz, I have elected to keep them large as they sound the best that way. This was after testing with a movie with a LOT of LFE and making sure I wasn't getting a lot of cone excursion (the ported design of the RB-25 must have a steep roll-off below 49 Hz).

I also found, in my setup (yours may be different) that a 60Hz crossover in the receiver is best when paired with my current speakers.

Rules of thumb:

1. Use the crossover in the receiver and set the sub crossover as high as it will go.

2. Fiddle with large and small settings for speakers to see what effect these have on the sub output. Always pay attention to how you like the sound!

[ygmn]

HOW IS SUB HOOKED UP?

Through normal l/r outputs or sub output....

sub output would be the best as the receiver would only direct the frequencies 80hz and lower.....

then set sub on yammy to BOTH...then the mains and sub will play below 80 and IMO sound the best...depending on main speakers...

[richinlr]

My sub (Klipsch RW-12) is connected to my receiver via a single coax from the LFE out on the Yamaha. It is then split at the sub and goes into the L & R jacks. Seems to work well - I have enough output from the sub to be able to control it and balance it with the rest of the system.

Now, I am not like some folks who want their sub to sound like the subs I hear in cars - I only want the sub to fill-in what's missing and round out the bottom end. In that regard the RW-12 is plenty sufficient for that. Depending on the movie, I STILL have a LOT of output in the LFE region (my wife complained about it the other day on one particular mivie).

[zyepod]

Thanks richinir...

That pretty much answers my question, except you said leave your Sub crossover as high as it will go... What about the volume on the Sub... Do you leave that as high as it will go also and do the controlling with the reciever as well?

[Ki Choi]

Alan:

Not to confuse you further but I would recommend the following:

1) At your normal listening position, you need to find out what your main L&R speaker will go down to. I did not see the make and model of your main speakers. Without the sub playing, you'd need to play series of low frequency tones. I am not certain if your receiver has low frequency generator built in. I do recall one of the older Yam RX-V1 receivers had it. If your receiver can not produce the low tones, I'd play test CD's with low frequency tones starting at 20Hz and goes up 1/3 oct. at a time. My guess is that majority of speakers will roll off drastically at 50Hz.

2) Use one of the Radio Shack's sound meters to measure whereyour main speakers are getting weak producing the low frequency.. They are not expensive but very useful as you get further into the HT setup (for proper sound level of your center and rear speakers, etc.)

3) Knowing your mainl speakers' low frequency limitations, I would then move over to optimizing your sub location. I would play the same test CD or any recording with good kick drums (not necessarily the low organ recordings). Disconnect your main speakers so that you are only hearing your sub. Move the sub around until you hear the maxium output without distortions. In general, corner placement works the best in most cases.

4) If you have a chioce of crossover slope, I would select the highest number for the steepest cut offs. I would pick "Small" as your main speaker selection and set the receiver crossover point to your main speaker low frequency drop off points. Set your sub crossover point to at least twice the receiver's sub crossover point.

5) Play the same test CD and adjust your sub level according to the sound pressure you would measure from your listening position.

If you'd like to borrow the low frequency tones for your trial, send me a PM.

Hope it helps.

Ki

[richinlr]

Thanks for the input Ki. You have gone more in depth than I did. I just don't have my RS SPL meter yet...

My recommendation on setting the crossover on the sub as high as possible was to make sure that I didn't have any intraction between the sub's crossover and the receiver's crossover. However, with some tinkering, you could get a really steep slope but I am leery of that because of potential phase problems.

Your recommendation on twice the receiver's crossover point is probably more than adequate.

Alan;

I run the level on my sub at about 2/3s - this makes about mid level in the receiver after YPAO. Some will tell you you should set the sub at full tilt and control it with the receiver (The theory behind this is good). In my case I believe it would be a problem because I would, no doubt, have to seriously cut the receiver's sub output and possibly have no range left for lowering the output on the receiver.

[zyepod]

Thanks for the great info... No dought I've learned more from both of you (Ki Choi, and richinlr) than a month of reading. Ki Choi your a little to high tech right now for me... maybe in a few months. (I will get those tones though) richinlr, you've come through again. I'm going to make some ajustments tonight while watching Master and Commander (excellent movie for working out your system) imo...

[Olorin]

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On 7/28/2004 12:59:34 PM richinlr wrote:

Some will tell you you should set the sub at full tilt and control it with the receiver (The theory behind this is good). In my case I believe it would be a problem because I would, no doubt, have to seriously cut the receiver's sub output and possibly have no range left for lowering the output on the receiver.

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Hi Rich,

Can you elaborate on what the theory is? I don't mean to challenge you or anything, but that seems counterintuitive to me. If I turn the sub way up and the receiver output way down, I'm asking the sub to apply lots of boost to a relatively weak signal. For my part, I don't like to turn an input signal down. Is there something I'm missing?

[richinlr]

Olorin,

Actually, I am in your camp on this point. I feel the same way about lowering the input signal level.

If I actually knew the level setting on my Yamaha reciever that resulted in the standard line out level, I would set the receivers level at that point and then do all the level controlling on the sub itself (actually makes more sense to me because that's, in essence, what we all do with CD players, DVD players, tape decks and so on).

Somewhere on this forum is an explanation of the other logic but I can't remember where it is.

In the case of my Yamaha receiver, I note that every level scale on the OSD has a middle point at which two bars appear. Is this the reference level? I don't know because the Yamaha manual has no information on this.

Brings me to a pet peeve of mine. Nowdays every instruction book for everything seems to be written with emphasis on the user being a total idiot. No one seems to put any meat in the manual. A good example of this is the contrast between a Klipsch Reference owner's manual and the manual for my ET LFT-VIII's - the Klipsch manual is about two pages (the English part) and the Eminent Technology manual is about 50 pages of all English! Extensive information on setup & placement, all the technical info (including design criteria and testing data - right down to the Thiel-Small parameters, crossover design and even the component values for the crossover).

I don't know about you but I like to have this data because it helps me make informed decisions on my own about how to set things up.