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Greg Oshiro

I finally got around to triamping my K-horns

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This is my first Klipsch forum post. I've been lurking sporadically for about a year. I think I finally have something to contribute.

I've wanted to triamp a pair of Klipschorns for more than 20 years. I finally got a room with reasonable corners, a pair of vintage K-horns and triamping paraphernalia. The image is the TEF measurents of both channels after I did the alignment.

The measurement was done in the listening room, 12' wide, 17' deep, 9' ceiling. K-horns on the 12' wall. Mic distance was 36" from the baffle, on-axis, height was midway between the lower tweeter edge and upper squawker edge. Two sofa cushions and 2 heavy wool blankets on the floor to attenuate the floor reflection. The measurement has about a 20 milli-second time window, so resolution is 1/3-octave at about 217 Hz, 1/10-octave at about 721 Hz and better as frequency increases. The 8.3% smoothing corresponds to 1/12-octave. I would ignore the data below 250 Hz ( I tend to think in ISO standard frequency increments).

Khorn_left_&_right

I'm pretty sure the dip around 200 Hz is a room mode.

It sounds bass-heavy to me, so I'll be tinkering soon...

post-53989-13819667494942_thumb.jpg

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Guest David H

Very cool, keep up the fine work, and welcome to the forums.

Dont try and equilize the (room modes) dips in the bass region, only the peaks. The dips are probably cancelations, and the more power you throw at it, the more it tends to cancel.

Dave

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The image is the TEF measurements of both channels after I did the alignment.

If you would, posting your crossover frequencies used (i.e., low pass/high pass on each driver, and crossover filter type/steepness), the delays for each channel used, the relative channel gains for each channel, and a picture of your speakers in room - would be really, really nice to have.

By the way: welcome to the forum. It sounds like you have some knowledge of this horn-loaded speaker business. Maybe you could share some of your experiences/background while you're at it.

Whereabouts in Arlington do you live, if I might be so bold?

Chris

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...welcome to the forums.

Dave

Thank you.

Dont try and equilize the (room modes) dips in the bass region, only the peaks...

Dave

Yeah.. I wasn't sure how to EQ the woofer. I did some measurements at the "sweet spot" and didn't get any data that made sense. The mic position used for the pictured data doesn't give sensible data for the woofer either.

What I ended up doing (which could be completely bogus) was placing the mic on the floor, centered on the K-horn, about 1/4" from the K-horn. My *unproven* theory is that the relative frequency response of an acoustic source in a trihedral corner can be measured with a mic near that corner as long as the mic is less than 1/4 wavelength from the source. Now.... in a room with reflections, the reflections will be attenuated relative to the direct (source-to-microphone) sound because they have to travel farther to get to the mic. If the reflected sounds travel 10 times farther than the direct sound, they will be 20 dB lower and contribute little to the measured data. If the direct sound path length is 1/2 the width of the K-horn or about 16 inches, that 1/4-wavelength at 211 Hz and the reflection travel distance for 20 dB loss is 160 inches, so as long as any significant reflector is farther away than 80 inches, *in theory* the data will be meaningful (see earlier warning about the theory).

So I put the mic on the floor, boosted 30 Hz, 1/3-octave bandwidth, 10 dB and flattened out the remaining peaks. I think it sounds better, but I'm biased. If some other forum mavens are willing to try this technique and provide their opinions, I'd love to hear them. Applying an EQ boost to a horn below cutoff is generally a bad idea, but the loudest level I listen at requires about 1 Watt of amplifier output. That 30 Hz 10 dB boost means 10 Watts *if all the power was at 30 Hz*. The K-horn woofer is rated at 100 Watts so I am not expecting smoke. After listening, I dialed the 30 Hz boost down 2 dB.

I did use the pictured data to set the woofer vs. squawker levels. I'm still playing with the woofer level setting and listening. I don't expect to have anything final for a month or two. I also want to get some known "golden ears" to listen....

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Guest David H

I also want to get some known "golden ears" to listen....

Not sure such a person exists. I know a few people that think they are. [:)]

I used my triamped setup for several years and really liked the sound, however I was always tweaking. Fortunately I was using a digital crossover with memory so I could easily reset to my base setting. Now, I am back to my passive crossover for simplicity.

Dave

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<snip> By the way: welcome to the forum.

<snip>

Chris

Thank you. You avatar gave me an idea for mine, although feline. If I can just get the cat to sit for a photo...

<snip>If you would, posting your crossover frequencies used (i.e., low pass/high pass on each driver, and crossover filter type/steepness), the delays for each channel used, the relative channel gains for each channel, and a picture of your speakers in room - would be really, really nice to have.

<snip>

Chris

That's a long list, and some (most?) are unlikely to apply to other folks' systems. Each range was smoothed with EQ while measuring with the TEF25, then filters applied to optimize the crossover, so the tuning is specific to these 2 K-horns. Also, settings from the Yamaha SP2060, when entered into another mfr/model DSP box will probably not provide the same "analog" frequency response.

If there are forum members with time-windowed acoustical measurements systems (TEF, SMAART, Praxis, EASERA, ...?) and DSP crossovers, Ken DeLoria is writing a series of articles for Live Sound Magazine:

http://www.prosoundweb.com/article/making_it_flat_analyzing_loudspeakers_dsp/

I don't know what he's going to write, but the first article looks like he's headed in the same direction that I took with the K-horns.

<snip> It sounds like you have some knowledge of this horn-loaded speaker business. Maybe you could share some of your experiences/background while you're at it.

<snip>

I have some knowledge of other types of speakers as well. I design pro audio speakers and systems professionally. Bass horns are out-of-favor with the pro world these days, especially the touring community, which is where I came from. If you attended a big rock show in the 1990's, there's about a 40% chance you were listening to a crossover system I helped to design. More recently I've designed speakers and systems for Universal Studios Japan in Osaka, as a sub-contractor to the sub-contractor....

<snip> Whereabouts in Arlington do you live, if I might be so bold?

<snip>

Chris

You may... via email. See my profile.

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I also want to get some known "golden ears" to listen....

Not sure such a person exists. I know a few people that think they are. Smile

<snip>

Dave

They do exist, but far fewer than there are pretenders. I know I am not one of them. The motivation for this project was/is to have a good reference system and learn how to listen better..

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Guest " "

so, what are you crossover points and what is the gain / power of each amp? Are you also running an active sub woofer? Do you have naked drivers or are there passives in between the drivers and the amp?.

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so, what are you crossover points and what is the gain / power of each amp? Are you also running an active sub woofer? Do you have naked drivers or are there passives in between the drivers and the amp?.

One of these days I might compile the DSP settings and post them. It's a lot of typing. As I said before in another reply, the DSP settings probably won't work with other DSP boxes or other K-horns.

Amps are 45W/8 ohms IIRC. Check the Crown web site for more data. There are stepped attenuators between the DSP and the amps so I can use more bits in the DSP. I think the attenuation is currently 18 dB. No additional subwoofer. Naked drivers.

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One of these days I might compile the DSP settings and post them. It's a lot of typing.

Really?

forums.klipsch.com/forums/p/143349/1465822.aspx

By the way, I believe that I live about 1 mile north-northeast of your residence (as a crow flies).

Cheers,

Chris

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By the way, I believe that I live about 1 mile north-northeast of your residence (as a crow flies).

That explains all the noise pollution he's been hearing....

[6]

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Well Richard, I HAVE been reading up on recording studio design, and its first requirement is sound isolation...maybe there's a cheap and easy solution to a noise issue in it...[:P]

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Welcome to the forums Greg. You have a great post to start out. I would be interested in knowing your choise of amplifiers. Some pictures of your system would be great.

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One of these days I might compile the DSP settings and post them. It's a lot of typing.

Really?

forums.klipsch.com/forums/p/143349/1465822.aspx

By the way, I believe that I live about 1 mile north-northeast of your residence (as a crow flies).

Cheers,

Chris

How close are you guys to 420 E Lamar or BVR, Sorry big Pantera fan.

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Welcome to the forums Greg. You have a great post to start out. I would be interested in knowing your choise of amplifiers. Some pictures of your system would be great.

Thanks for the warm welcome.

Amps are ancient Crown D-75(not A). Chosen only for low cost on eBay, balanced inputs and low power. At this point I consider them the weak link in the chain. There are balanced stepped attenuators in between the DSP and the amps. That way more bits of the DSP are used. The attenuators are currently set for 30 dB of attenuation, so that's 5 more bits than with no attenuators, for the same listening level.

One of these days I should design & build a "Really good 5-Watt amplifier" times six. I started one on the circuit simulator, but ran into a stability problem I haven't bothered to beat into submission.

I'll post some pix one of these days, when I get a "Round Tuit". Visually, its pretty underwhelming, though.

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How close are you guys to 420 E Lamar or BVR, Sorry big Pantera fan.

I'm about 10 mi from 420 E Lamar. "BVR" threw me for a loop. Googling "BVR" AND Pantera returned some stuff about "Big Vin Records". Is that the BVR of which you speak (er...type)?

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This link took me to an "oops!" page. I assume it's your DSP settings....

I took a look at your profile... Yikes! What *don't* you have?

Here is the correct link I believe. The text was right but the underlying hyperlink was corrupted. I'll fix the one above.

http://forums.klipsch.com/forums/t/143349.aspx

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How close are you guys to 420 E Lamar or BVR, Sorry big Pantera fan.

I'm about 10 mi from 420 E Lamar. "BVR" threw me for a loop. Googling "BVR" AND Pantera returned some stuff about "Big Vin Records". Is that the BVR of which you speak (er...type)?

Yup, Big Vin Records. At least thats the address for the recording studio. I always heard that the Abbott Brothers such as Viny and the late Darrell have lived in that area.

Your Khorns sound like they would sound nice I hope you enjoy them.;

Nick

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I've made a few changes:

  1. Original setup was CD player analog output to DSP box analog input. It's now CD player SPDIF to cheap HOSA SPDIF-to-AES3 converter to DSP box AES3 input. It's louder. Post-DSP-box attenuators changed from 18 dB to 30 dB attenuation. It sounds *much* better. I think it's because the CD player D/A converter and DSP A/D input converter are no longer in the chain. Also, the Yamaha DSP box analog input can take something like 20 volts before it clips. I think the CD player puts out 2 volts at 0dBFS. I think the new connection uses more bits in the DSP box.
  2. The low frequencies around 63 Hz pile up when listening in stereo. there is now a gentle (-2 dB, 63 Hz, Q=2) cut in the overall EQ of both channels that sounds better to my less-than-golden ears.

Other impressions:

  1. Walking around the room, I can plainly hear the polar pattern of the tweeters. In the old passively crossed-over days, this was not so obvious.
  2. The passive crossover had a very"splashy" high-hat sound. It now sounds much more like the real thing.
  3. Reverb tail decay can now be heard in much greater detail. I use Steely Dan's "Babylon Sisters" track for this evaluation.
  4. Drum attack, especially toms, sound better.
  5. The "air" around saxaphones is clearer.
  6. The difference between recordings with/without low-frequency extension is much clearer.
  7. It is easier to listen to individual instruments in a mix.
  8. Pianos sound much more realistic.
  9. I'm listening to Lyle Lovett's "Live in Texas" right now. I can hear him inhaling between phrases.

Over all, I'd say this doesn't suck. ;)

What differences between passive and triamped setups have you folks heard?

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