I heard Rigma's jubs! nya, nya-ya, nyaan, y***

[Coytee]

I did this on the one in Hope and Richard's (gently[:$])

So THAT is where the knuckle prints came from!!! []

I don't have any scientific basis for my next comment but from a functional point of view, I've always been a bit anti-MDF. Perhaps they made it better now than before but I simply like the strength of the plywood over MDF. I also hate that MDF doesn't mix well with moisture and I've had too many screws either strip out or simply rip through.

Hmm.... I wonder about this... just thinking outside the box a bit... could you take 1/2" plywood and 1/2" MDF, GLUE them together to get 1" material and then make your project out of that laminate?

You'd have some of the strength of the plywood and some of the mass of the MDF. The MDF could be put on the inside of the enclosure so if your stuff is in a basement and you had a leak, the plywood exterior would get wet first, possibly saving the MDF from destruction.... hmm....

As I said...I've got no scientific basis for my preference so it's just that, a preference to plywood.

[Deang]

The structural material contributes to the behavior and voicing of the speaker.

For better or worse, PWK's thoughts on the subject.

[mark1101]

Guys,

Thanks for all the comments. I was out last night and could not answer.

Dr. Who....I undoubtedly do have room issues. I'll leave it at that. You could be right about standing waves. But I know what I hear.

Dean...I screwed up. I DO have measurement equipment, and it's in my system. I have a 31 band DBX 2231 EQ that helps me understand the sound of individual tight bands. I am sure what I hear is below 80 hz. I've had EQs in my homes since I was a teenager. They are a nice tool to learn what certain frequencies sound like. Obviously, much better tools exist.

JC....AlK recalculated the resistor values in the Jub networks for me a few months ago and I am using 10 and 12 ohm resistors now. Already done.

I've tried the different taps on my amps and 4 ohms never sounds as good as 8 to me (Jubs, Khorns, LaScalas, Corns, Hersesys).

Richard.....You could be right about the Khorns in your room. I won't say they work any better in my house. But I do like how they work. []

Question: In 1973 what would "ruggedized" speakers be crafted from besides plywood? Obviously, PWK experimented and knew the performance numbers.

[PrestonTom]

Have you guys noticed that the lowest bass exists in between the speakers (and even slightly behind them if you stand in between them), not in front of them? I have moved my Jub clone cabinets all over the place and this is what I notice. My cornwalls do this to some extent too.

When I say "in between" I mean standing as if you are a center channel speaker. Right in the middle of them in a straight line.

What are the dimensions of your room? I would bet $20 that the frequency you hear is going to correlate to a standing wave in your room. In other words, what you are hearing is room related and has nothing to do with the speaker...You should notice this behavior with every speaker you put in the room, and almost regardless of its position too - which seems to correlate with your perceptions with the cornwall. The only exception will be when you have a speaker that happens to have enough directivity to avoid stimulating the standing wave.

Mike (and Dean), You have hit it on the head. At low frequencies (large wavelengths), there will be a "build up" in SPL near the boundaries (eg walls and especially where the wall intersects another wall, floor or or ceiling). This, of course, is why bass traps and absorbers are best located in these same positions.

Regarding the measurement issue: Yes it is always good to do this. Yes, it easy to hear (without physical measurement) that the bass gets louder near a corner or a wall. However, unless you do this sort of thing on a very regular basis, it is quite difficult to correctly describe the degree of gain (other than the simple description that it is "louder") and even more difficult to accurately judge the frequency content (saying it was low frequency is an easy judgement, saying that it was about 80 Hz is remarkably difficult for most). The problem is further compounded since these informal observations are being made with "music" as a "test" signal.

Good Luck,

-Tom

[Deang]

Question: In 1973 what would "ruggedized" speakers be crafted from besides plywood? Obviously, PWK experimented and knew the performance numbers.

Particle board, more bracing, screws, etc.

[Deang]

"I DO have measurement equipment, and it's in my system. I have a 31 band DBX 2231 EQ that helps me understand the sound of individual tight bands. I am sure what I hear is below 80 hz. I've had EQs in my homes since I was a teenager."

I appreciate what you're saying Mark, but an equalizer is not a measuring tool (unless it has a built in RTA). It's difficiult for me to admit this, because I like to think I hear pretty good too -- but the microphone has made me feel like an idiot on several occasions. Bob and Al always told me that the ears lie, and I always thought they were full of it until I started measuring. You mention "individual tight bands", but your EQ is undoubtably 1/3 octave, and adjusting one of those also moves quite a bit on either side of the designated frequency. Now, you might be 100% correct in what you think you're hearing, but you can't be 100% sure until you stick a microphone in there.

"Mark maybe you tried this but the Jubs LF Horn is pretty much a 4 ohm load and are best driven at 4 0hms on a tube amp in this region. How that balances with what you are using for a HF section will depend though."

Even on the four ohm taps, the improvement in damping will be marginal compared to that of a good SS amp.

[mark1101]

You are right. I won't argue that the test equipment doesn't lie.

[Deang]

I won't argue that the test equipment doesn't lie.

Well, let's not get carried away.

[IndyKlipschFan]

Now now..... Let's not forget personal taste too.. hehehehehehehehehehehe

That EQ, if your going to use one... Is very nice!

I have one myself for PA / Karaoke.. it may not be pretty graph wise.... but trust me, you can find a LOT of bass in La Scala's hahahaha

And yes, I know it does not make it right. LOL

[Deang]

lol, so when you getting a mic? Wanna borrow my rig sometime?

Ha ha. Sure, I would love to borrow it, you gonna teach me how to use it? Al has something for me, but I think I need a crate the size of Rhode Island and a team of Hueys to get it over here. I have a ton of saved email from Shawn on how to set up a system with the right software, but I really want to use a good laptop with external soundcard -- need money. I did have a Behringer unit after I installed Al's Trachorns into the Klipschorns. I learned a lot, and got frustrated a lot too! Measure the speaker, measure the room, measure the speaker, measure the room. Adjust this, adjust that. Back two squares, move three forward. Sounds good with this CD, doesn't sound good with that one. Hmmm, now THAT sounds different -- what did it do? I was finally struck with an epiphany, "You don't know what the hell you're doing". O.K., it wasn't that bad, I did learn a thing or two. The unit was more useful to me for seeing what was happening with network, horn, and driver change outs -- but wasn't really all the useful for "fixing" what I didn't know was broke or not. One of my weaknesses is that when I get frustrated with a piece of gear, it gets a UPS label as soon as I can print it. I do wish I had it now, I would like to know some things. Demands on my time right now make it difficult to dedicate the large blocks of time I need to learn what I want and need to learn. "Daddy, can I have drink?" "No, I'm busy right now, dehydration is good for you."

http://forums.klipsch.com/forums/1/575163/ShowThread.aspx

[IndyKlipschFan]

Dean " I was finally struck with an epiphany, "You don't know what the hell you're doing".

Oh man have I been there and done that... I am still in the woods on some things I have learned and since fogotten.

I know some very flat speakers, that look just fantastic on a graph or paper...to me.... sound like crap!

I also heard some very cool, although not my cup of tea, but I admit pretty cool QUAD (I think + $20,000 something) speakers yesterday. Again someone at that price LOVES em.

[Islander]

The structural material contributes to the behavior and voicing of the speaker.

For better or worse, PWK's thoughts on the subject.

In the letter, it appears that PWK was referring to heavy-duty drivers, not to the cabinets. That letter was dated 1973. Does anyone know if he changed his opinion later, as technology changed (and hopefully improved)?

[Deang]

You're right. I took "loudspeaker" to mean the unit as a whole but, but yeah, I see that now -- he means the driver(s). Nice catch.

That would make for an interesting topic -- '"Things that PK changed his mind about".

[IndyKlipschFan]

"Things that PWK changed his mind about".

I am pretty sure at the Pilgrimage someone said the K horn was changed drivers or mod wise over 60 times.. Something to consider when better drivers and improvements were indeed found. (Yes, the basic concept remained the same though..)

[DrWho]

lol, so when you getting a mic? Wanna borrow my rig sometime?

Ha ha. Sure, I would love to borrow it, you gonna teach me how to

use it? Al has something for me, but I think I need a crate the size of

Rhode Island and a team of Hueys to get it over here. I have a ton of

saved email from Shawn on how to set up a system with the right

software, but I really want to use a good laptop with external

soundcard -- need money. I did have a Behringer unit after I installed

Al's Trachorns into the Klipschorns. I learned a lot, and got

frustrated a lot too! Measure the speaker, measure the room, measure

the speaker, measure the room. Adjust this, adjust that. Back two

squares, move three forward. Sounds good with this CD, doesn't sound

good with that one. Hmmm, now THAT sounds different --

what did it do? I was finally struck with an epiphany, "You don't know

what the hell you're doing". O.K., it wasn't that bad, I did learn a

thing or two. The unit was more useful to me for seeing what was

happening with network, horn, and driver change outs -- but wasn't

really all the useful for "fixing" what I didn't know was broke or not.

One of my weaknesses is that when I get frustrated with a piece of

gear, it gets a UPS label as soon as I can print it. I do

wish I had it now, I would like to know some things. Demands on my time

right now make it difficult to dedicate the large blocks of time I need

to learn what I want and need to learn. "Daddy, can I have drink?"

"No, I'm busy right now, dehydration is good for you."

http://forums.klipsch.com/forums/1/575163/ShowThread.aspx

Wow, I wonder how I missed that thread? If that's the measuring gear

you're referring to, then I can totally see why you felt nothing

correlated to what you heard.

Will you be at the pilgrimage? I plan to bring my measurement rig and

would have no problem showing anyone how it works. Right now I've got

it pre-configured so all you need to do is press go. And if you're

feeling really lazy, you can just send me the file for

interpretation...though I'm more than willing to help explain how to

interpret yourself too. Interpretation is the hardest part - and not

being there to hear it for myself makes it all the more harder to find

things to support what I think I might be hearing. However, one of the

coolest things about measuring is that I can convolve music with the

measured impulse response of your system to get an idea of what you're

hearing - there's a term for this fancy process, but it escapes me at

the moment. It's not perfect because my system will impart its own

colorations onto the signal, but with headphones I should be able to

grow accustomed to their limitations and not have to worry about the

effects of my room.

Hey, maybe I should set it up during the mixer to see how golden everyone's ears are?

[DrWho]

Does anyone know if he changed his opinion later, as technology changed (and hopefully improved)?

I dunno about his opinions, but the bandwidth versus output tradeoff he

was referring to is deeply engrained into the science of loudspeaker

engineering. Newer technology may have widened bandwidths for the same

SPL and similar distortion, but the tradeoff is still there: if you want it to play louder with the same distortion levels, then you need to sacrifice bandwidth.

[Islander]

Does anyone know if he changed his opinion later, as technology changed (and hopefully improved)?

I dunno about his opinions, but the bandwidth versus output tradeoff he was referring to is deeply engrained into the science of loudspeaker engineering. Newer technology may have widened bandwidths for the same SPL and similar distortion, but the tradeoff is still there: if you want it to play louder with the same distortion levels, then you need to sacrifice bandwidth.

I don't often listen at high volume, but I recently bought a Yamaha 500Wpc amp, not for the power, rather because of its really low distortion and noise specs, with its lowest measured distortion in the 6-10 watt operating range. Most of the time, I'm listening at 1 watt or less and I seem to be able to hear further back into the soundstage without turning up the volume, so the extra clarity is appreciated, even if it means I can hear surface noise on LPs a little more clearly, too.

Anyway, the extra power/headroom, even running at 1 watt or less, seems to add solidity to instruments. Instead of just hearing piano strings, I can sense a big wooden thing there across the room, and other instruments benefit, too. I didn't expect that, but I'm liking it more all the time. At high volume, it might be called slam, but at low volume, it's more like presence (and I don't mean a midrange "presence" boost).

It may seem silly to drive La Scalas with 500Wpc, and I have to be careful when changing inputs and always make sure to turn the volume way down before powering off, but the power isn't going to waste. Maybe heavy-duty drivers that would give the Scalas a 500-watt continuous rating instead of 100 watts would have reduced bandwidth (and maybe sound quality), so perhaps the best bet is regular drivers, a big clean amp, and some common sense with the volume control.

[DrWho]

My 2 cents...

All amps are non-linear devices and their level of amplification will

change ever so slightly at different power levels. With typical audio

amplifier topologies, these non-linearities usually become crazier the

closer you get to peak output. I think it would make more sense to

consider the linearity and distortion levels of the amplifier in the

ranges that it will be operated in. The actual peak output capabilities

of the amp don't really matter. But the reason I bring this up is to

point out that transients in music tend to be way above the continuous

levels. So even if you only listen at 1 watt, a 30dB transient will

have peaks on the order of 1000W (yikes). Thats probably an extreme

example, but it's not uncommon in the music I listen to (which is the

only music I've had the ability to measure). Not squishing these

dynamics is going to give things a bit more liveness. Squishing them

nicely can impart attributes similar to what is achieved with a good

compressor/limiter and I suppose some even like this sound.

Another thing to consider though, is that higher output amps

(especially pro amps) tend to have much larger damping factors. This

means the dynamic load of the speaker is going to have less of an

impact on the amplifier. In other words, the speaker always changes the

behavior of the amplifier. The magnitude of this change is going to

depend on a few factors, but the damping factor is a good indicator to

determine the influence of the speaker. Rarely is it the case that the

speaker changes the response of the amplifier in a beneficial way, so

in general it is something to avoid.

I gotta run, but there is one more thing I'd like to comment on...having to do with the distortion levels near 0W power output.