Law of diminished returns

[Scrappydue]

Since I got the La Scala IIs a couple of years ago

may i ask what makes a la scala ii a jubscala? i see it has a 510 horn on it but there are a few different cinema speakers that have the 510 horn so i was wondering what it has to do with a jubilee? 

[Schu]

to that point, how do you guys manage this stuff against your home owner's insurance? Absolutely none of my gear was purchased from a brick and mortar, most of it is used, and half of it was through trade.

 

 

THAT, good sir, is a very good question.

 

at the moment I am flying by the seat of my pants and only have Photographs of everything. I would be interested in everyone's opinion on that subject matter seeing as everything was made or purchased second hand.

[joessportster]

My current system is more resolving in all but 1 way of anything I had in the past.........................Soundstage is the biggest drawback with headphones I have come to accept that compromise 

 

this system cost 2200.00 and outshines some 20k systems I built B-4.  Even though I have 1/10th the amount of money tied up I can still see that any improvement will be minor at best  (except that Metrum Octave 2 Dac)

[oldtimer]

It's covered under contents.  Just make sure contents equal the value covered.  Otherwise make sure you have a replacement at cost clause.

[oldtimer]

Or don't worry and be happy.  If you have less than ten grand involved and contents covers that you can probably do better for the same ten grand next time.  Or maybe you want apocalypse insurance.  Good luck collecting, it was an apocalypse! 

[TJIann]

I listened to The Doors "Waiting for the Sun" today on vinyl through my vintage McIntosh/Klipsch system.  It sounded the way I remembered hearing it as a teenager on vinyl through the Technics/Pioneer system my parents bought me.  I was in bliss.  Some of the best produced recordings ever, and while many of the CD versions are inferior, the original vinyl sourcing is just incredible.   =music bliss to me.  No equipment improvements needed.  

[Islander]

 

Since I got the La Scala IIs a couple of years ago

may i ask what makes a la scala ii a jubscala? i see it has a 510 horn on it but there are a few different cinema speakers that have the 510 horn so i was wondering what it has to do with a jubilee? 

 

 

The Jubilee, in its original form, is a KHJ bass bin with a K402 or K510 tweeter horn with a K-69 tweeter attached to either one of those horns.  It is bi-amped, and is EQ'd by an active electronic crossover, an EV Dx38.  This provides a higher degree of accuracy in correcting the frequency response, plus it allows the woofer and tweeter to be time-aligned.  With the large difference in the length of the bass and treble horns, this improves the sound noticeably.

 

The Jubilee is usually driven by a pair of matching power amps, because the low 480 Hertz crossover point means that the tweeter actually uses a bit more power than the woofer.  The matching amps ensure that the timbre of the bass section matches that of the treble section.

 

The JubScala is an economy version of the Jubilee.  Like the Jubilee, it can have a K402 or K510 tweeter horn.  It uses a La Scala or La Scala II bass bin, but is also bi-amped with an active electronic crossover.  Going from 3-way to 2-way eliminates one crossover point, but is only possible with modern wide-range tweeters like the K-69 or the much more expensive TAD 4002.  There is always a phase shift at the crossover point, so if one can be eliminated, that's a good thing.  It reduces distortion.

 

Very low distortion is the strong point of the Jubilee and the JubScala.  Their high sensitivity also allows for more realistic dynamics than many other speakers.

Edited June 17, 2015 by Islander

[Marvel]

because the low 480 Hertz crossover point means that the tweeter actually uses a bit more power than the woofer.

You sure about that? The compression drivers a way more efficient than the drivers/woofers in the bass bins. Most every setup I've seen has a much more powerful amp on the bottom than what is driving the tweeters.

 

Bruce

[Islander]

 

because the low 480 Hertz crossover point means that the tweeter actually uses a bit more power than the woofer.

You sure about that? The compression drivers a way more efficient than the drivers/woofers in the bass bins. Most every setup I've seen has a much more powerful amp on the bottom than what is driving the tweeters.

 

Bruce

 

 

I'm very sure about that.  Most setups are as you describe, but Jubilees and JubScalas are unusual.  Most speaker systems have much higher crossover points than Jubilees or JubScalas.  1200 or even 1800 Hz is not unusual.  In that situation, the woofers are reproducing most of the audio range, and therefore use most of the power required by the speaker.  There was a chart on here some time ago that showed the effect of different crossover points on the "load-sharing" between woofers and tweeters, but I haven't seen it for some time.  Seeing the concept rendered visually is a big help in making it more clear.

 

Think of the audio frequency range in terms of octaves (20-40 Hz, 40-80 Hz, etc.).  There are 10 octaves between 20 Hz and 20,480 Hz.

 

With La Scalas, you can ignore the 20-40 Hz octave, so you can say their operating range starts at 40 (or 50) Hertz.  That takes it down to 9 octaves.

 

With a crossover point of 480 Hz, the woofers are covering the bottom 3-1/2 octaves, while the tweeters cover the top 4-1/2 octaves.  Each octave represents about the same amount of power, so the 160-320 octave requires as much power as the 2560-5120 octave, and the same as the 10,240-20,480 octave.  Naturally, music does not have an equal distribution of content from bottom to top frequencies, but an ideal speaker system should be able to reproduce whatever content is sent to it.

 

The advantage of the 480 Hz crossover is that most of the vocals are reproduced by the tweeters, which makes for better sound.  I don't know all the reasons, but I've read on the forum that having vocals reproduced by woofers is not the best way to go.

 

My setup has the speakers driven by a pair of dual-mono Yamaha MX-D1 power amps.  One 2-channel amplifier drives the left and right woofers, and the other one drives the left and right tweeters.  In operation, the tweeter amp does run a little bit warmer than the woofer amp.  I may get a power meter one day and confirm this with actual numbers, but you can see the principles involved.

 

As for the difference in efficiency between the tweeters and woofers, this is true in most speaker systems.  The usual solution is to reduce, or "pad down", the output of the tweeters to match the output of the woofers.  This is done in the crossover, whether it's active or passive.

Edited June 17, 2015 by Islander

[Islander]

joessportster, it looks like I may have unintentionally hijacked your thread. I didn't mean to, and I apologize for it.

[jacksonbart]

I like to listen to music

[joessportster]

joessportster, it looks like I may have unintentionally hijacked your thread. I didn't mean to, and I apologize for it.

Hijack away, its all about audio in the end

 

Cheers  

[Deang]

No it's not, it's about going broke.

[derrickdj1]

I'm very sure about that. Most setups are as you describe, but Jubilees and JubScalas are unusual. Most speaker systems have much higher crossover points than Jubilees or JubScalas. 1200 or even 1800 Hz is not unusual. In that situation, the woofers are reproducing most of the audio range, and therefore use most of the power required by the speaker. There was a chart on here some time ago that showed the effect of different crossover points on the "load-sharing" between woofers and tweeters, but I haven't seen it for some time. Seeing the concept rendered visually is a big help in making it more clear.

 

It would be nice to see some chart.  Just thinking about the equal loudness curve and the increase power needed to make a 40 Hz note sound as loud as a 1 kHz, this does not sound correct.  For example:

 

Bass frequencies don't take any more power than any other frequencies at the same SPL, but we are much less sensitive to bass frequencies so for a low note to sound/feel as loud as a midrange or high note (until our hearing drops off) it takes much more power. For example, to sound as loud as a 1 kHz tone at 70 dB SPL, a 40 Hz tone must be at 90 dB. That extra 20 dB is 100 times the power! So if your speakers only need 1 W to produce that 70 dB, 1 kHz tone, then a 40 Hz tone requires 100 W to sound as loud.

[Islander]

It took some searching, but here's the chart I referred to. It's actually a table, not a chart. It shows the power distribution at different crossover frequencies and is from a speaker design manual.

http://sound.westhost.com/bi-amp.htm#power_dist

Scroll down to "1.3 - Power Distribution and SPL" to see it.

The chart shows the "equal power" frequency to be 350Hz. As other posters have pointed out, the relative sensitivity of the bass and treble drivers would produce different numbers in certain cases. The paragraphs after the chart mention this.

With the Jubilee and JubScala, the nominal 480Hz crossover point makes the tweeters need a bit more power than the woofers. I'd be guessing if I were to try to put numbers to it. I just know that the treble amp runs a bit warmer than the bass amp at typical living room listening levels.

Edited June 20, 2015 by Islander

[AllenTacey]

When the sound is exactly what it is supposed to sound like, reproduces an excellent sound field where you can recognize for instance in classical music the woodwinds sound like they are isolated into their proper position string section where it belongs a piano does not sound weak in is tones, horns can be individually identified french horn from trumpet, saxophones, tubas and trombones all distinct. Cello, viola and violins from the highs to the lows remain seated not moving left and right on the stage. Rock music has a stage? Of course and if you know the group you know their positions drum set always in the middle Bass guitar on left, lead guitar centered while rhythm guitar is on the right. Guitars are crisp can rip can sound like Chuck Berry's "ringing a bell" while Country has "chicken picking" and hip-hop, rap, jazz or soul the bass needs to be very clear not that muddy shit pouring out of an overdriven car speaker. Listen to Stanly Clarke for Bass. Listen to Dave Brubeck for jazz. Listen to Muddy Waters BB King and/or Eric Clapton for Electric Blues. Paul Butterfield or Sonny Boy Williamson for harmonica. Frank Sinatra sang in perfect pitch as did George Jones. If you have a wide variety of music but just two speakers reproducing the sound between 20Hz to 35Hz for the low range up to a high range between 20kHz to 24kHz +/- 0 to 3dbs (I have an unhearable 1Hz to an unhearable 250kHz +0 -3 {and hearable from 30Hz to 24kHz +/-0}) THD .5 preferably .05 (.005 in my case) you probably have unbeatable reference sound. Earspeakers are usually sonically perfect and put out about 115dBs of sound pressure. Klipschcorns put out 114dBs @ 1 watt and can be deafening with a 1000 watt per channel amp. I am driving 2 speakers producing 98dBs each at 1 watt with a 2.5 dynamic range, somewhere over 600 watts @ a total harmonic distortion of .0005 above 1800Hz and .05 under 1800Hz. So what you need is achievable. I invested over a thirty five year period around $3000. Currently have $378 into amplifier, $300 into preamp, $540 (cost now $1800) into a turntable, $1000 into speakers, $350 into earspeakers. The sound is extremely close to a $75,000 system who's sound I used as a goal. Hope this helps!

Edited July 15, 2015 by AllenTacey

[AllenTacey]

I am retired from everything. I am happy that my 2 speaker system creates and maintains a sound stage. I am dumb but I know how each instrument sounds and where it is placed. So my system reproduces sound where "Is it Live or is it Memorex" is the theme. I am no longer looking to change anything about my share. I have arched ceilings so the speakers go on the side where the wall is the shortest. The floor is hard and reflective so my ceiling absorbs. Behind the speakers it is flat smooth and hard while the wall behind my listening position has shelves. The wall on the right is vacant and smooth while the wall to my left possesses all of my media. Between the speakers sets my antique equipment cabinet having removed the 1950 tube system replacement circa 1980 solid state equipment that delivers the maximum power my new Klipsch R-28F's are supposed to accept. This was the finishing touch an acoustic environment for the hobby I love. This has to be the best hobby a man can have. Hot damn time to get back to tweaking my ears...