Settings for tri-amping an '82 Belle with an active digital crossover

[Chris A]

(See post #50 for using the Belle with a Beyma CP25 tweeter.)

(Here is another link to 3-way "JuBelle" settings that replace the K-500 midrange horn/K55 driver with a K510 horn/K69-A driver)

Here are the settings that I'm currently using on an ElectroVoice Dx38 active crossover for a center Belle (1982). These are not meant to be taken as gospel, just a starting point for those of you thinking about tri-amping your La Scalas or Belles (La Scalas have very similar characteristics, except for a slightly longer midrange horn). If anyone sees any issues with these settings, please let me know.

In order to tri-amp the Belle's drivers, I bypassed the Belle's "AB" passive crossover and connected to each driver using the AB crossover terminal blocks to each amplifier channel.

By the way--the difference in sound quality is pretty significant, IMO.

Belle Klipsch - EV Dx38 Tri-Amp Settings

v1.4 (Final, 8 August 2014 - overhauled settings to simplify PEQs and minimize group delay)

IN1: Master EQ1 -- Type Bypass

IN1: Master EQ2 -- Type PEQ, f: 460 Hz, Q: 0.7, Gain: -6 dB

IN1: Master EQ3 -- Type Bypass

IN1: Master EQ4 -- Type Bypass

IN1: Master EQ5 -- Type Bypass

IN1: Master Delay -- Delay: 1.9ms, Unit: ms

IN2: Master EQ1, Type: Bypass

IN2: Master EQ2, Type: Bypass

IN2: Master EQ3, Type: Bypass

IN2: Master EQ4, Type: Bypass

IN2:Master Delay -- Delay: 1.9ms, Unit: ms

IN1+In2: Master Delay -- Delay: 1.9ms, Unit: ms

_

Out1:Routing, Source IN1, Label LO

Out1: CHANNEL EQ1,Type: PEQ, f: 180Hz, Q: 2.6, Gain: -11dB

Out1: CHANNEL EQ2,Type: PEQ, f: 160Hz, Q: 2.2, Gain: -3dB

Out1: CHANNEL EQ3,Type: PEQ, f: 188Hz, Q: 1.0, Gain: -10dB

Out1: CHANNEL EQ4,Type: PEQ, f: 66Hz, Q: 22, Gain: -3dB

Out1: HIPASS XOVER, Type: thru

Out1: LOPASS XOVER, Type: Linkwitz 24 dB, f: 600Hz, Pol: norm

Out1: CHANNEL DELAY, Delay: 0.0 us, Unit: us

Out1: COMPRESSOR, Thrsh: 0dB, Rat:1/2.0, Attack: 0ms, Rels:100ms

Out1: LIMITER, Thrsh: 0dB, Release: 100ms

Out1: Level: 0dB, Polarity: Normal

_

Out2: Routing, Source IN1, Label MID

Out2: CHANNEL EQ1,Type: Bypass

Out2: CHANNEL EQ2,Type: PEQ, f: 3.4KHz, Q: 1.3, Gain: 6dB

Out2: CHANNEL EQ3,Type: Bypass

Out2: CHANNEL EQ4,Type: Bypass

Out2::HIPASS XOVER, Type: Linkwitz 24 dB, f: 600Hz, Pol: norm

Out2: LOPASS XOVER, Type: Linkwitz 24 dB, f: 4.9KHz, Pol: norm

Out2: CHANNEL DELAY, Delay: 979 us, Unit: us

Out2: COMPRESSOR, Thrsh: 0dB, Rat:1/2.0, Attack: 0ms, Rels:100ms

Out2: LIMITER, Thrsh: 0dB, Release: 100ms

Out2: Level: -17.5dB, Polarity: Normal

_

Out3: Routing, Source IN1, Label HI

Out3: CHANNEL EQ1, BYPASS

Out3: CHANNEL EQ2,Type: PEQ, f: 4.9KHz, Q: 4.5, Gain: -9dB

Out3: CHANNEL EQ3,Type: PEQ f: 12.4KHz, Q: 6.5, Gain: -8dB

Out3: CHANNEL EQ4, BYPASS

Out3: HIPASS XOVER, Type: Linkwitz 24 dB, f: 4.9KHz, Pol: norm

Out3: LOPASS XOVER, Type: thru

Out3: CHANNEL DELAY, Delay: 2167 us, Unit: us

Out3: COMPRESSOR, Thrsh: 0dB, Rat:1/2.0, Attack: 0ms, Rels:100ms

Out3: LIMITER, Thrsh: 0dB, Release: 100ms

Out3: Level: -2.0dB, Polarity: Normal

_

(Channel 4 not used for this application - center channel only)

_

* EV recommends using the same settings for its low pass/high pass filters.

 

[Speakmeister]

Chris, I thought the K500/K55 got knid of nasty up at the top end of it's range. Could you try getting into it at 4K or so like the modern klipschorn or la scala II?

[Chris A]

Not a problem to change the settings. It takes about 10 seconds to change the two filter frequencies. I initially set the frequency higher to match the Belle's actual crossover point. Note that Klipsch Heritage crossovers do not electrically attenuate the midrange on the hf end - it rolls off due to the driver limitations itself. The tweeter is rolled off below the crossover frequency. See Al K's site to verify what I'm saying.

Also note the 24 dB/octave Linkwitz-Riley filters used here to minimize the crossover band between tweeter and midrange: This is pretty important when trying to minimize "lobing" of the tweeter/midrange crossover region.

Chris

Edited May 2, 2014 by Chris A

[Chris A]

By the way, the tri-amped Belle seamlessly integrates with the Jubs. The original Belle AB crossover sounded harsh and its timbre off but once tri-amped and time-aligned, the Belle disappeared acoustically. When she first heard it, my wife spontaneously mentioned the soundstage was continuous and easy on the ears--and that she didn't know that it could be like that.

Note that the advantages of active tri-amping or bi-amping are more than just "it sounds better".

The tri-amped Belle center improves multi-channel SACDs/DVD-As, and HT mode is equally impressive.

Chris

Edited May 2, 2014 by Chris A

[Chris A]

Total upgrade cost to tri-amp the Belle = ~$600 (US) including Dx38 crossover, cables, and Crown D-75A amplifier. (Actually, I already had these items in-hand.)

EDIT: By the way - to upgrade a pair of Belles or La Scalas to the "JuBelle" or "JubScala" configuration via bi-amping, the cost would be the $600 above + the cost of the K-402/K-69-A or K-510/K-69-A horns/compression drivers from Roy Delgado at Klipsch (roy.delgado@klipsch.com).

The difference in sound quality from the JuBelle/JuScala upgrade from their stock configurations is difficult to quantify.

Suffice it to say that you will hear a "really BIG difference".

Chris

Edited May 2, 2014 by Chris A

[Chris A]

Chris, I thought the K500/K55 got kind of nasty up at the top end of it's range. Could you try getting into it at 4K or so like the modern klipschorn or la scala II?

I just found the K-55/K-500 Horn FR.

Edited May 2, 2014 by Chris A

[Chris A]

Here is the equivalent plot for the K-77 tweeter. Divisions on this plot are apparently 2 Khz. I don't see a lot of solid overlap between these two drivers/horns.

[Chris A]

Note that I updated the tweeter delay based on some experimentation - the 0.25 ms decrease in delay was very audible. The Belle now integrates much better with the Jubs in my 5.2 speaker array.

I also updated the crossover filter frequencies to drop the crossover frequencies ~1 Khz. The present values shown in the table above.

Chris

[Chris A]

Bumping this in reference to another thread discussing driver delay correction accuracy. In this case, a further correction at a center frequency of 4.5 KHz of 0.25ms between the Belle tweeter and midrange was such a dramatic improvement that I now have currently shelved plans to upgrade the Belle top section with another horn+driver. The Belle now integrates much more seamlessly. The only thing that gives way the Belle in the front speaker lineup is its smaller apparent source width than the K-402s/TADs, and the lack of extreme low frequency below ~80 Hz.

Note that the character of the Belle changed in a major way when tri-amped and delay-corrected for its three drivers: the Belle was just not able to integrate with the Jubs using its stock passive crossover.

Chris

[Chris A]

Updated 1 May 2014 to reflect new crossover point between midrange and tweeter (lowered in frequency) and the addition of PEQ filters on the midrange and tweeter channels to correct for driver FR irregularities.

The Belle now sounds even closer to the Jubs on each side in terms of timbre and apparent source width.

If there are any comments or suggested updates to these settings, please feel free to list them here.

Chris

Edited May 1, 2014 by Chris A

[The Dude]

I came across this when I was searching for the peq settings of the Jubscala. I know it's completely different,but I used the peq settings you posted for the bass bin. Wow what a difference it made. At first I was doubting the Lascala bit, but do to these settings I have changed my mind.

[DeanG Crossovers]

EDIT: Removed snarky comment. Sorry.

Edited June 21, 2014 by DeanG

[Chris A]

It's interesting to me how much the timbre of the Belle changed after correcting for the time misalignment of its drivers. It's also very easy to demonstrate the difference ( A-B ) with and without this correction.

Also, it's a snap to change any settings in real time to hear their effect. There are available filter slots for fine tuning that are still available for each channel (see settings at the top of this thread). This could provide the functionality to implement MikeTn's (mikebse2a3) "Cello Palette" on two-channel systems, or in my case, center channel in a 5.1.

Chris

Edited May 2, 2014 by Chris A

[jorjen]

It's interesting to me how much the timbre of the Belle changed after correcting for the time misalignment of its drivers. It's also very easy to demonstrate the difference ( A-B ) with and without this correction.

Also, it's a snap to change any settings in real time to hear their effect. There are available filter slots for fine tuning that are still available for each channel (see settings at the top of this thread). This could provide the functionality to implement MikeTn's (mikebse2a3) "Cello Palette" on two-channel systems, or in my case, center channel in a 5.1.

Chris

Chris, what exactly do you hear/not hear when misalignment is corrected? Just how significant a difference is it ?

[Chris A]

It sounds like I've got the wrong speaker between the Jubs when the delays are not corrected: a timbre mismatch.

This is most pronounced between the tweeter and midrange horns/driver if not corrected. Pianos don't sound right and female voices are also disturbed - perhaps "bigger than life" and not well focused within the soundstage image but simultaneously a narrow/thin soundstage image overall.

The midrange-bass bin crossover region sounds disturbed in timbre in the tuning fork "A-440" to middle-C region, and it gets worse/wider in its affected frequency band if using a gentle-slope crossover filter - such as 12 dB/octave Butterworth vs. 24 dB/octave L-R that I'm using now. The uncorrected sound is disjoint and nasal/horn-like in timbre. This is a bit more difficult to hear than the tweeter/midrange crossover distortion, but once you crank the delay correction back in and listen using A-B comparisons, it gets much easier to hear.

The soundstage image is disturbed where I can hear the center channel instead of it blending into one frontal soundstage image with the Jubs on either side (i.e., without delay correction). It also sounds like the Belle is very narrow in its apparent source width without correction, but blends very well when corrected.

The result of the two corrections is fairly extreme in my setup: I couldn't use the Belle between the Jubs without the delay corrections, IMHO.

Chris

Edited May 5, 2014 by Chris A

[sunnysal]

I must admit I ran the active crossover for a while and went back to passives. I am not saying to anyone that is the definitive answer to the often asked question but...I never felt the sound quality was noticeably better, or perhaps not better enough to justify the extra "trouble". I must also admit I still have most of the equipment and watch these threads closely. warm regards, Tony

Edited May 6, 2014 by sunnysal

[Chris A]

I must admit I ran the active crossover for a while and went back to passives. I am not saying to anyone that is the definitive answer to the often asked question but...I never felt the sound quality was noticeably better, or perhaps not better enough to justify the extra "trouble". I must also admit I still have most of the equipment and watch these threads closely. warm regards, Tony

Khorns actually have the most to gain by correcting time delays. Could you describe your equipment and settings used for your active crossover including make/model (a digital crossover...right?), amplifiers and preamplifier used, as well as some idea of the type of music that you typically used to make your decision?

Chris

Edited May 7, 2014 by Chris A

[Chris A]

Tony,

That's too bad that your experience wasn't good - my experiences have been uniformly outstanding using EV Dx38s and the Yamaha SP2060, all three of which I picked up on craigslist for less than $500 (US) each.

I see from earlier posts (31 October 2007 and before) that you were using a DEQX and JBL 2404H "baby cheek" tweeters. Are you still using the JBLs? I haven't used any DEQX crossover units, but I read where there are others that tried it and had trouble with software maturity, programming complexity, and disappointing SQ.

Chris

Edited May 9, 2014 by Chris A

[Chris A]

Updated the settings list to reflect in-room EQ of center channel only using SPL measurements and the Dx38 PEQs and shelf filters (...as in I finally got around tuit... ).

Many changes in this version. I decided to promote it to version 1.0 to reflect the really big improvement in integration with the Jubilees on each side. Now +/- 2 dB from 80 Hz to 16KHz in-room

Chris

[DeanG Crossovers]

Curious about the use of the word "timbre" in this thread. I don't see how a timbre match can be obtained since the Belles are still using phenolic diaphragms. Phenolics have their own character, they don't sound anything like titanium or aluminium -- so I'm guessing they wouldn't sound much like Beryllium either. I associate "timbre" with the character or sonic signature of the driver.

Edited June 21, 2014 by DeanG