Help choosing a design for some towers

[---k---]

It could very well be the receiver is doing it wrong. Don't know.

Incorrect phase will cause things to image incorrectly. You should be able to tell a difference if you flip the wires at the terminals on one speaker.

With the Avia CD, there is a phase check test. It plays what sounds like pink noise. When it is correct, the pink noise sounds like a point source dead center between the speakers. When the phase is incorrect, the pink noise fills the room and sounds dispersed. Get the Sound and Vision test disc out. It should resolve the phase issue quickly. I'm starting to think you probably have it correct.

If your woofers or mids are wired incorrectly, but the same on both speakers, I don't think this would cause the receiver to report a phase error. Someone can correct me here. But, it would cause a very narrow null at the crossover frequency. When you had the mids wired wrong, you had a null around 350hz and 1800hz. The 350hz null will make drums sound weak. The 1800hz will make female vocals lack that bottom end. It can be subtle, but very obvious once you notice it.

I'm still bothered by you saying the crossover was 200hz. Does your receiver select the crossover frequency? Mine doesn't, it just sets them to small and relies upon the user to select the frequency. Did it set it this high with your old speakers.

We're likely worrying over nothing. Maybe though just to be safe, put up some good photos of your crossovers. I'll look at them.

[bf_brock]

I think my receiver doesn't know what it's talking about. It does auto select the crossover frequency but you can over-ride it. I took each speaker out, check all wiring to and from the crossover. It looks correct to me. For the hell of it I swapped ends on the left channel at the receiver and it reported correct phase, but bass output definitely seemed lower. I remember my receiver has an LFE tone generator built into it. It goes down to 39Hz, and the Khans definitely had output at 39Hz.

I'm listening to music right now and they seem fine to me. I'd imagine I have to listen to some really high dollar to hear something better. I'm still sticking to my statement of them being the clearest speakers I've ever heard. So I guess if something is wrong that would be really annoying but nothing sounds wrong to me. The better the recording I put on the better they sound and regardless of what I play they still sound good. So they're staying the way they are...Well until I put the spikes on and move the crossovers (they're just sitting on top of the speakers).

[cjd]

So if I swap the wiring to the mains (even though I know that part is right) and it tells me it's right I should be able to hear a difference, correct? What if it's worst after that? At that point I should probably just ignore it?

You shouldn't hear a difference if you flip both - one, maybe (it's a lot easier with a disc like Avia doing the flip). Some people say they can, and maybe so, but I'm skeptical The problem here is what frequency range is the receiver keying off for phase? Technically, you're 180 backwards in the woofer section, so wiring the mains "backwards" will correct this. However, it'll also flip the relative phase of the whole speaker, and that may ultimately be what is required. It may just be a question of getting the relative phase of your mains and center squared away, and that may take flipping wiring to either the center, or to both mains.

Ryan has a center that I *also* "wired backwards" by suggesting the woofers be wired off.

Also, if the reciever picked 200Hz when the one had its midrange wired backwards, I'm not surprised! It would detect the null and significantly reduced bass output this causes!

C

[bf_brock]

You shouldn't hear a difference if you flip both - one, maybe (it's a lot easier with a disc like Avia doing the flip). Some people say they can, and maybe so, but I'm skeptical The problem here is what frequency range is the receiver keying off for phase? Technically, you're 180 backwards in the woofer section, so wiring the mains "backwards" will correct this. However, it'll also flip the relative phase of the whole speaker, and that may ultimately be what is required. It may just be a question of getting the relative phase of your mains and center squared away, and that may take flipping wiring to either the center, or to both mains.

Ryan has a center that I *also* "wired backwards" by suggesting the woofers be wired off.

Also, if the reciever picked 200Hz when the one had its midrange wired backwards, I'm not surprised! It would detect the null and significantly reduced bass output this causes!

C

Actually I had only swapped the ends of one of the speakers and it said it was correct but it didn't sound right. I'll break out my calibration disk tonight and test the phase with that but it doesn't sound like something is off. After correcting the wiring of the midrange on the left speaker both speakers sound the same to me now.

[cjd]

If you swap only one speaker, it's going to be wrong. Gotta keep both mains matched. And, by that swap, we mean change the leads from the amp to the speaker.

Absolute phase determination in a room can be a nightmare. Too many extra contributions.

[Dennis H]

Ryan has a center that I *also* "wired backwards" by suggesting the woofers be wired off.
C

Why? Do you disagree with the notion that the woofers of all the speakers should be in phase (the old correlated at long wavelengths thing) and let the highs do what they will? Moving your head a few inches is enough to throw the tweeters out of phase so it doesn't make any sense to try to match the phase up high.

Edit: okay I think I get what you are saying -- the center woofers are in phase with the L&R woofers but move backward with a + signal. Still seems backward to me given the standard conventions but, oh well, you're putting designs out there and I'm not so consider me shut up.

[cjd]

Because it's easier in the program to flip one rather than two? :P

Seriously, it doesn't matter, right? You can "wire backwards" to the binding posts and have everything be right again.

The signal range that I personally find most clearly affected by phase changes is covered squarely by the midrange. But it's already probably way wrapped, and it's only relative phase changes in that range not absolute phase changes, that I find easy to hear.

So, I have no idea.

C

[bf_brock]

Last night I watched my first movie with the Khan's in place. It was Next in HD-DVD. Not a great movie but it had decent action and good audio track. Got to say it made me want full range speakers all around. The Khan's sound great with movie sound tracks. There was much more impact than I used to get with the JBL's and they're definitely more "full range". I think it was the first real workout they've had.

[---k---]

:T

When you starting on the center?

[bf_brock]

Not sure when I'll be starting on the center. I'm thinking I may get a new amp before that. I have a Fosgate Audionics amp that has been solely used for sub duty. I was planning on using it to power the Khan's but two of the four channels have stopped working. I'm thinking of repairing it or just getting a new amp but that'll push the center further out on the to-do list.

[---k---]

What are you powering them with now? Receiver? How does it handle them and their bad 4ohm load?

[bf_brock]

I'm powering them with my Yamaha RX-V1500 receiver. Seems to do fine. Even pushing them along with the center and rear channels for a movie soundtrack. What are you powering them with?

[---k---]

Behringer A500. I'm not sure if I would recommend it though. Not that it isn't up to the challenge, but mine has a bit of an overhanging ring to it. I didn't notice it at first, but ever since CJD pointed it out to me, I've been looking for it and now hear it. Especially after being up at his place and doing listening with his different amps. Maybe I got a bad one?

My Pioneer receiver seemed to do fine with them also. It doesn't have the ring. But, the A500 seems to be a bit more dynamic and have more punch. I'm tempted by new amps, but I think I've spent enough this year. Though, I keep looking at the new Emotiva stuff, Outlaw, and also the DIYcable Exodus. But, that is another thread.

[bf_brock]

I've actually been eying the Emotiva stuff too.

[Geoff Gunnell]

The new Emotiva amps maybe -- but not the MPS 1/2 IMO. I bought one and AB-d it against Rotel 1095s through both B&W aluminum domes and Vifa XT25's -- a little on the bright side. A guy at A Very Similar forum PMd me with a similar experience through Dali Helicon 400s. And I've run across a couple reports that with below 4 ohm loads the safety shutdown triggers earlier than one would expect. Hopefully the new models don't have these problems. YMMV etc.

[Jim Holtz]

The new Emotiva amps maybe -- but not the MPS 1/2 IMO. I bought one and AB-d it against Rotel 1095s through both B&W aluminum domes and Vifa XT25's -- a little on the bright side. A guy at A Very Similar forum PMd me with a similar experience through Dali Helicon 400s. And I've run across a couple reports that with below 4 ohm loads the safety shutdown triggers earlier than one would expect. Hopefully the new models don't have these problems. YMMV etc.

I'm not a fan of their class H amps. The LPA-1 and the new XPA series are all class A/B. they definitely aren't bright and have tons of power. When the folks on the Emotiva forum were talking about the IPS and MPS having more detail, bright came to mind. Most of them have either Rockets or Klipschs for speakers. Not exactly the most neutral or accurate, IMHO.

I have the hots for a XPA-5 to replace my LPA-1 for no good reason other than the XPA-5 has balanced out puts and tons of power. It could easily be the last amp I buy. However, The LPA-1 loafs driving my Statements to reference levels so I really don't need more power. I just want it.

Jim

[bf_brock]

Thanks guys for the info on the Emotiva stuff.

Oh, I forgot to mention some I discovered. Remember when I said that my receiver's auto calibration set the Khan's to Small and 200Hz crossover. Well the other day I think I found out why; a bass null right in the area of where I put the calibration mic. I normally don't sit right in that spot so I didn't notice. So messed with the speaker toe-in and now the bass is much more even across all the listening positions.

[bf_brock]

Well I made some amp changes. I found an old Radio Shack 1-channel PA Amp I had and hooked my sub up to that, thus freeing up the two channels still functioning on my Fosgate amp. So I hooked the Khan's up to the Fosgate amp. The result? The Fosgate amp is definitely up to the task. The lower frequency performance is noticeably improved with much more solid and full bass.

[bf_brock]

Ryan,

You wanted me to report on the ported bass after listening to them for awhile. So here's my take on the ported version. I have not listened to the sealed version so I can't make that comparison but this is what I think of the ported version:

Clean and accurate. The bass is tight, not boomy, and I've never noticed the woofers straining on any material. They just seem to have as much bass or as little bass as is in the recording. It just sounds good.

[bf_brock]

So CJD, you got a ported version of the Khancenter to match my ported Khan's?

[cjd]

It's just a box size change, with ports tuned to suit. Crossover doesn't change.

Also, if you've the space, the RS225/RS150/RS28A center will also match this well - at least, the crossover option I posted in that thread will.

C

[bf_brock]

It's just a box size change, with ports tuned to suit. Crossover doesn't change.

Also, if you've the space, the RS225/RS150/RS28A center will also match this well - at least, the crossover option I posted in that thread will.

C

Which thread would that be? I couldn't seem to find the post you were referring to.

[---k---]

Stuff a pair of socks in your ports and report back!

I expected the ported to sound excellent. I'm glad it is working out well for you, and that you're happy.

CJD, you going to let him off that easily with the center? You're not allowed to build the Khancenter, you must build three exactly matched speakers! When C was over at my house, he was measuring up my TV stand and telling me that the regular Khanspire would fit in there on its side! Three perfectly match speakers - the perfect center!

The Khancenter is great. Not sure if it is clear from CJD's post, but this is the other center he is suggesting: http://www.htguide.com/forum/showthread.php4?t=22393 He has a crossover for it. Just bigger bass drivers - RS225 vs. RS180.

If you want to go ported on either of these, I'm sure we can come up with a box size and tunning. A lot will depend on where you plan on placing it.

[bf_brock]

Well heck, if I can just build another Khanspire and turn it on it's side...:idea:

Right now my center channel is on speaker stands in front of my entertainment center. Actually I think that works well and is probably where it'll be located forever. I would like to have a center channel that's pretty full range.

As a side note, does anyone know how the Yamaha RX-V1500 or similar Yamaha models handles the bass management on multi-channel input? Does it just pass the inputted signal or does it apply the bass management settings?

[bf_brock]

How much more output are we looking at when comparing the RS225 vs. RS180?

[bf_brock]

Wow, I'm a jackass. So I finally break out the Sound & Vision calibration DVD. According to the phase test it's agreeing with my receiver in that the front speakers aren't in phase. Well since I've quadruple checked everything something can't be wrong. What the heck is going on here? So I go ahead and re-check everything AGAIN. Guess what?! I wired something wrong. Argh!!! Turns out I had the midrange output wired wrong on the right speaker.

I corrected that and now the phase sounds correct in the tests. As far as how it sounds with music, I'd say the only thing I really notice is that they image better now. It was weird because I had this feeling like the left speaker was always a little more prominent but speaker levels showed they were the same. That's gone now, it was apparently an imaging issue.

[Dennis H]

it was apparently an imaging issue.

Way more than that. You had deep notches in the SPL at the XO frequencies with the reversed mid. It's amazing how crude our ears are at picking out what's wrong -- something doesn't sound quite right but we can't figure out what it is. That's why we measure as well as listen.

[---k---]

Hahahahaha.
I only laugh, because I was right there with you. Wiring these things up isn't easy the first time, or the second time, or.... Someone more experienced than will have to let us know how many speakers it takes before it is second nature.


Dennis,
Some would argue that because our ears are that crude, measuring isn't needed. Measurements are only showing us what we can't hear. :P Though I agree with you completely. But that is an off-topic debate that doesn't belong here.

[Dennis H]

I think our ears can tell us if it sounds right or if something sounds wrong. They just aren't very good at telling us exactly what is wrong.

[cjd]

It took me a couple minutes of listening to Ryans to arrive at the conclusion he'd wired his woofers wrong. It was, as you say, immediately obvious something was wrong, but still a couple minutes to get there. And then hope I was right about what was wrong 'cause otherwise it meant I'd *still* managed to mess u the crossover. Mind, I have a full lifetime of music training (my mom taught and conducted so from before I was born...) so my ears have a little higher percentage of brain cells trained to process data.

Imaging will improve, no surprise there. Stage should be deeper if you've got enough breathing room on these - any spatial properties are ALL about phase relationship(s).

I think ears are superb instruments. I think our brains suck at really understanding the data they provide.

[---k---]

I was going to steal one of your photos and add it to the build thread as an example of a ported enclosure, but the fancy web app doesn't make it obvious to me how I can easily steel it. Can you post a good photo that you would be proud to have everyone see. I'm really interested in the side profile showing the increased depth - I was trying to steel the angled shot you have.

[bf_brock]

I was going to steal one of your photos and add it to the build thread as an example of a ported enclosure, but the fancy web app doesn't make it obvious to me how I can easily steel it. Can you post a good photo that you would be proud to have everyone see. I'm really interested in the side profile showing the increased depth - I was trying to steel the angled shot you have.

Sorry I didn't respond sooner. My back went out and I've been recovering from that. I'll get a photo posted later tonight.

[bf_brock]

Here are a couple photos that you can use. Let me know if there is a different one that you wanted. I couldn't attach them because the file size is too large.

Link to photos

[---k---]

I was thinking about the 5th one down on the right. But, if you prefer a differnt one, okay....

[bf_brock]

I added that pic to the link I posted above.