JubScala?

[Edgar]

Anyone using AES/EBU digital inputs in their digital Xovers and bypassing the A/D conversion??

Not set up at the moment, but back when I had my full system up and running, I ran directly from the SPDIF output of my CD player to the AES/EBU input (yes, they are compatible) of my digital crossover. Had a six-channel passive volume control (two speakers, each triamplified) between the outputs of the DACs and the inputs of the amplifiers.

Wonderful.

Greg

[ClaudeJ1]

OK, so which units do you consider a "modern design."

Anything that does not use a dual-range ADC. Modern monolithic converters are achieving very high dynamic range and SNR, and good sound, without the need for range switching.

I get that, but how does one figure out which brands and models have this feature.....like the EV DC one or Ahsly Protea, or Behringer?

[DrWho]

I believe 90 dB noise floor (linear scale) is good enough.

I'd say that 90dB of dynamic range is good enough, but what is the final SPL of the noise floor? If your 90dB covers 50dB SPL to 140dB SPL, then chances are you're not using about 30dB of that dynamic range, and now you're down to 60dB of dynamic range (ouch)....and at 50dB SPL, you're gonna be above the noise floor of the room so it's not gonna be masked completely.

Btw, even though most music masks the noise of the XTi, not all source material will mask it all the time. I get especially distracted during the rests in music when it should be quiet, but it sounds like there's a flooded river just outside my house...

[mikebse2a3]

If your 90dB covers 50dB SPL to 140dB SPL, then chances are you're not using about 30dB of that dynamic range, and now you're down to 60dB of dynamic range (ouch)....and at 50dB SPL, you're gonna be above the noise floor of the room so it's not gonna be masked completely.

I could be totally wrong here but I'm pretty sure no one here is playing their music at 140db in their home listening room...[]

Again just my opinion but bottom line the EV DX38 is an excellent processor and if it's features meet your requirements and it can be bought at a reasonable price it's well worth using. As I mentioned before the Input/Output analog level controls can prove to be a very good benefit when implementing it into systems that include consumer type amplifiers having possibly high input sensitivity and/or different input sensitivity and no input level controls themselves to adjust for the best signal to noise.

Again in my opinion newer designs by EV and others can offer increased capabilities at lower prices with excellent sound quality as well and the only caution I would give when recommending them (especially when using them with a consumer type amplifier's without the ability to adjust their input levels and/or with different amplifiers having input sensititviy differences) is some method (ie: attenuators) to deal with the high input sensitivity of some amplifiers might be required to optimize the system.

mike tn

[curt248]

I just got home with 4 more la scalas. I drove for 10 hours today. phew.

One of the guys I bought them from had 10 la scalas stored in a room.

It was some sort of sound company that sets up the sound for large venues. One of the guys that worked there said the la scalas sound great when comparted to thier pro equipment. The only problem with them is the ease of moving them and thier non-modern look.

It was a nice little adventure today.

[Islander]

I'd hazard a guess that one of the least objectionable forms of distortion is noise floor--if it is very low as it is here--even if that noise floor is modulated at very high SPL. PWK once commented on the unnaturally "ghost-like quiet" in digital recordings of the 80s.

Could that be due to the low-level limits of 16-bit CD recordings? As I understand it, 1 bit is used for error checking, leaving 15 bits for dynamic range. If the recorded sound falls below the 1-bit threshold, it disappears. Very low-level sounds that might be audible on LPs or DVDs can't be heard on CDs.

Has anyone else seen references to this?

[Islander]

Again just my opinion but bottom line the EV DX38 is an excellent processor and if it's features meet your requirements and it can be bought at a reasonable price it's well worth using. As I mentioned before the Input/Output analog level controls can prove to be a very good benefit when implementing it into systems that include consumer type amplifiers having possibly high input sensitivity and/or different input sensitivity and no input level controls themselves to adjust for the best signal to noise.

Those knobs come in very handy, allowing me to actually eliminate hiss, or just lower it to where it's only audible within a few feet from the speakers, and not at all from across the room. BTW, the hiss is not volume dependent.

That trade-off means the overall volume can still be really high if needed. Those level controls give a useful degree of flexibility.

[Islander]

I just got home with 4 more la scalas.

Once you get your La Scalas decoratively arranged, we'll be wanting to see some pictures. []

[Chris A]

Could that be due to the low-level limits of 16-bit CD recordings?

The linked reference makes several points - one of which is the issue at that time(1984) with digital recording techniques using the then-new CD format. I believe PWK was talking about recordings made at too low level that was suppressing the background noise level at threshold conditions.

But also note that he was talking about relative peak-noise level for real environments - his answer was something more like 50-60 dB as that which exceeds any typical recording environment. That comment was right on the mark for the conversation about Dx38 noise floor, IMHO.

Chris

[Edgar]

As I mentioned before the Input/Output analog level controls can prove to be a very good benefit when implementing it into systems that include consumer type amplifiers having possibly high input sensitivity and/or different input sensitivity and no input level controls themselves to adjust for the best signal to noise.

Again in my opinion newer designs by EV and others can offer increased capabilities at lower prices with excellent sound quality as well and the only caution I would give when recommending them (especially when using them with a consumer type amplifier's without the ability to adjust their input levels and/or with different amplifiers having input sensititviy differences) is some method (ie: attenuators) to deal with the high input sensitivity of some amplifiers might be required to optimize the system.

Absolutely. It can be a problem when using pro equipment in a consumer situation. The expected input and output levels are different, so the output amplification on pro equipment can be so high that what would be a perfectly tolerable noise floor to other pro equipment is intolerably high to consumer equipment, even though there is absolutely nothing wrong with either one. The right way to deal with it is to place some attenuation between the outputs of the pro equipment and the inputs of the consumer equipment.

Greg

[Edgar]

Could that be due to the low-level limits of 16-bit CD recordings? As I understand it, 1 bit is used for error checking, leaving 15 bits for dynamic range. If the recorded sound falls below the 1-bit threshold, it disappears. Very low-level sounds that might be audible on LPs or DVDs can't be heard on CDs.

Oh, good heavens. I'm afraid that you have been misinformed.

First, in a 16 bit CD, all 16 bits are available for dynamic range. Error checking is a completely separate issue, and there are many other bits devoted to that.

Second, with proper dithering, if the recorded sound "falls below the 1-bit threshold", it does not disappear. Modern dithering and noise-shaping schemes can yield 16-bit dynamic range approaching 120 dB, at frequencies below ~10 kHz or so, at the expense of less dynamic range at higher frequencies, where it doesn't matter anyway because we don't hear so well up there.

See, for example, here.

Greg

[curt248]

Back to the Jubscala post.

Does anyone have the crossover settings for the stock la scalas?

I was thinking that while I save up for the big $1000 each k402's, I could buy another dx-38 (I need two since I want my center jubbed out too) and use them with my 2 main speakers with the stock drivers.

I was thinking of recapping my three fronts that have the al-3 crossovers with a kit from bob crites for ~$150, but I could get another dx-38 for $450 and have better sound with the equipment I'm going to eventually need anyway.

What do you guys think?

[edwinr]

Wow! I was trying to read through this thread and ran out of steam at page 12! What about a JubBelle? Similar specs to a LaScala. Anyone got any pics of such a modification?

[fyrpwr]

I have a pic on page 18 of the 510/K69 Belle in my HT.

[Coytee]

Aside from cranking my head 90 degrees, it looks very petite!

Perhaps we should rename it:

The Little Runt?
Heresy?
The Little Bit**?
R2-Jube2?

Just tossing out some ideas.

Back to Curt, I'd imagine some of the engineer type would be able to give you the crossover info you want. Maybe not as exact as the chamber would give but good enough to keep you moving.

I also agree it makes more sense to nab another Dx instead of blowing those funds on passive parts that will get pushed aside when you're done.

[ClaudeJ1]

I'd hazard a guess that one of the least objectionable forms of distortion is noise floor--if it is very low as it is here--even if that noise floor is modulated at very high SPL. PWK once commented on the unnaturally "ghost-like quiet" in digital recordings of the 80s.

Could that be due to the low-level limits of 16-bit CD recordings? As I understand it, 1 bit is used for error checking, leaving 15 bits for dynamic range. If the recorded sound falls below the 1-bit threshold, it disappears. Very low-level sounds that might be audible on LPs or DVDs can't be heard on CDs.

Has anyone else seen references to this?

I actually sent PWK a reel to reel tape of some classical CD's (Telarc), but he never commented. I tried to fool him, maybe I didn't fool him, I'm not sure. I know that we have come a long way in digital processing since 1983. I remember the only thing you could get was a Sony (I was a young AES member and knew the technology was coming in the from all the papers of the late 70's. I experienced DBX compander master recordings with over 90 db dynamic range over Khorns at my local Klipsch dealer. I coudn't wait for digital to come to the masses. Klipschorns were "digital ready" since day one, and everyone else had to catch up, eh?

[ClaudeJ1]

If your 90dB covers 50dB SPL to 140dB SPL, then chances are you're not using about 30dB of that dynamic range, and now you're down to 60dB of dynamic range (ouch)....and at 50dB SPL, you're gonna be above the noise floor of the room so it's not gonna be masked completely.

I could be totally wrong here but I'm pretty sure no one here is playing their music at 140db in their home listening room...

Again just my opinion but bottom line the EV DX38 is an excellent processor and if it's features meet your requirements and it can be bought at a reasonable price it's well worth using. As I mentioned before the Input/Output analog level controls can prove to be a very good benefit when implementing it into systems that include consumer type amplifiers having possibly high input sensitivity and/or different input sensitivity and no input level controls themselves to adjust for the best signal to noise.

Again in my opinion newer designs by EV and others can offer increased capabilities at lower prices with excellent sound quality as well and the only caution I would give when recommending them (especially when using them with a consumer type amplifier's without the ability to adjust their input levels and/or with different amplifiers having input sensititviy differences) is some method (ie: attenuators) to deal with the high input sensitivity of some amplifiers might be required to optimize the system.

mike tn

Thanks for emphasizing this point. It's not just a relative gain/front end sensitivity issue of the power amplifiers, but one of each section. The 2-way guys have it much easier than the 4-way guys like me (Mark Fragnito is going 5-way with his MCM stack and subs, yikes). But, hey the guys that have the KP 600 stacks are 5-way right out of the gate, so it's not for the squeamish, eh?

Either way, the bigger the horn, the better the horn, but you gotta control it and stop somewhere. I still like the Italian engineer who built his own amps and poured concrete sub horns with an Fc of 10 Hz. under his house and driven with only a 6W amplifier in ordr not to blow the walls out of his house (8-18" horn loaded drivers x2 channels will do that ya know.).

Jub Scalas represent a truly "miniature" compromise and probably gets everyone who does it the very best sound in a small, easy to build, all horn setup. I still believe in time delays and horn subs to go with it, and the only way to get there is active Xovers.

[edwinr]

Thanks fyrpwr. I checked your system profile. It answered all my questions regarding the horn, crossover etc on one hit: Belle/510/K69 Delgado/Crites Passive Xover.

[edwinr]

... and I read the rest of this thread discussing the K510/K69, particularly page 18 with the excellent pic of fyrpwr's JubBelle center channel. Phew!!!

[SSnyder]

Cost no bject Patrican (see dicsusson elsewher} is truely ultemate speaker. Desinged by inventer of all Klipsch (TM[] but with no holes barred all out. Class act not ugly cienema industrail