XKi - X's ab initio Karlson 6th Order Bandpass

[xrk971]

XKi W5-876SE Sub RTA measurements and Sound Clips

Here are some distortion measurements at 2.83V and 1m for 31Hz, 60Hz, 120Hz, and 200Hz. Also some bass heavy sound clips that I know generally tax the performance of woofers and subs. Clips are from a TC9FD Dagger TL in a FAST with XO at 250Hz. Sub is giving a pretty wide bandwidth performance - about 3 octaves.

RTA was produced using Sine generator in REW and RTA function in REW with 16-sample average. HD is typically less than 1% at 1 watt input and circa 85dB to 90dB.

30Hz:

60Hz:

120Hz:

200Hz:

Let me know what your impressions are after listening to the bass...

 

[BYRTT]

Truly a work of art , gorgeous FC build X !

Agree looking the five build pictures #252 say it all.

xrk971,
Thanks sound clips though i hate to say not so good this time, they too bass heavy kind of dull and kind of boxy. Know system setup actually can sound great in your room and to analyze reason ask if you have changed recording setup because use to be 44,1kHz these are 48kHz files.

 

[xrk971]

Hi Byrtt,
Thanks for the honest assessment. The clips were chosen to excercise the bass extension - I did not work too hard on getting the tops to be integrated well enough. Let me try them with another top (maybe Nautaloss with PRV 5MR450NDY) - I think the TC9FD may have been under powered relative to sub SPL. Also pick a clip you know well for relative comparison.

 

[freddi]

re: 3 clips, I'm not familiar with this type music - the first two clips seem to have a "hit" edge somewhere in the midrane - the third with vocal is interesting and bass sounds deep and solid for today's mixes - I didn't hear much "gargle". Considering such a high crossover to the DaggerTL, its pretty good. There did seem to be a digital artifact (?) in the mp3s. Do you have suggestions for this sub with larger drivers - say two 10 or 12" ?

 

[xrk971]

I have a dual SWS 10D4 design that hits 35Hz at 125dB in a 2.8 cu ft external box.

 

[freddi]

2.8CF sounds great - wonder how good the thermal performance on those 10s holds up at high spl? can it do much at say 200 watts in? do you think the design lends itself to higher cutoff for some bass guitar duty with lower mass speakers rated say 96-100dB at 1W?

btw - Ray Brown's bass on the cut below doesn't sound very good - I'm still on gaming headphones which have too much adjustment capability - between "sub" "front", etc.
- don't know if its clean or not - mids are good

https://www.youtube.com/watch?v=pf45Y7TuFRk

 

[BYRTT]

That's a great explanation that focus was put to bass extension where i focused on hole sound picture especially because that TC9FD in dagger TL and combined FAST system have before made one of the best quality sound clips of yours.

With that in mind the three sound clips are fine and prove low extension .

 

[BYRTT]

.....btw - Ray Brown's bass on the cut below doesn't sound very good - I'm still on gaming headphones which have too much adjustment capability - between "sub" "front", etc.
- don't know if its clean or not - mids are good

https://www.youtube.com/watch?v=pf45Y7TuFRk

Hi freddi at my place on main speakers and headphones the bass guitar signature is fine and close to natural but its level in the hole mix is too loud. Listening at my small full range speakers for desktop computer which have a higher low end f3 point than above setups the hole mix sounds fine.

EDIT forgot to say it's good music .

 

[freddi]

hi BYRTT - thanks for the balance comments on that track - - Oscar was almost too fluent for blues

 

[xrk971]

2.8CF sounds great - wonder how good the thermal performance on those 10s holds up at high spl? can it do much at say 200 watts in? do you think the design lends itself to higher cutoff for some bass guitar duty with lower mass speakers rated say 96-100dB at 1W?

btw - Ray Brown's bass on the cut below doesn't sound very good - I'm still on gaming headphones which have too much adjustment capability - between "sub" "front", etc.
- don't know if its clean or not - mids are good

https://www.youtube.com/watch?v=pf45Y7TuFRk

I agree Freddi, that bass sounds very one-note and distorted - almost like the mic is too close and is clipping. Sounded awful on my speakers and just as bad on my Sony MDR-v6 monitor headphones. The rest of the ensemble sounds good as well as the ambient sounds of a night club.

 

[BYRTT]

I agree Freddi, that bass sounds very one-note and distorted - almost like the mic is too close and is clipping. Sounded awful on my speakers and just as bad on my Sony MDR-v6 monitor headphones. The rest of the ensemble sounds good as well as the ambient sounds of a night club.

Because we have different experience listening the track think take a listen again tomorrow with fresh ears. Agree sounds like a close mic ing on the bass and not other instruments and sometimes down the track but only sometimes it's clipping and in general too loud in the mix. Bass is very dynamic sounds free clean of compression/limiter/gate.

 

[freddi]

its unusual for Ray Brown's bass to be that screwed up - he had impeccable technique and shadings - it may be a difficult instrument to mic/isolate in practice. Some of those Joe Fick videos with old-school slapped upright bass are good for comparing speakers.

 

[xrk971]

I will listen with fresh ears and also on my reference system for comparison. Maybe I did not give it a long enough play time and it gets better?

 

[freddi]

it sounded screwed up to me on my headphones - like improperly mic-ed - generally Ray Brown's bass sounded good in the 1950's onwards - maybe Telarc botched that live recording

here's a nice ensemble - Slam Stewart's bass is kinda muffled but its a lot of fun to hear his typical unison singing with the bowed bass https://www.youtube.com/watch?v=gwnBn-EFaI8

5/4 Maple Leaf Rag https://www.youtube.com/watch?v=lHXxgC_ddbw

 

[xrk971]

Look at what a K-aperture can do for a messy polar

I did a careful study of some 3in drivers here (http://www.diyaudio.com/forums/full-range/270094-objective-comparison-3in-4in-class-full-range-drivers.html) and took a polar of the new PS95-8 driver from Dayton. It is a nicely built 3in paper cone full range with cast basket.

Here is the polar in an open faced Nautaloss at 0.5m with 4ms gate:

Putting that driver in the XKi I built for the RS100-4 and you get this - quite an amazing improvement in polar uniformity at the cost of a few sharp dips. Less than a 5dB variation between o dg and 45 deg at 10kHz and less than a 2dB variation up to 30 deg, and the mess at 15kHz really cleaned up to a consistent peak rather than wide variability - this means applying EQ can work as it is angularly independent:

Here is the bass extension and HD, not bad - very listenable and with some "air" due to the enhanced response above 10kHz - like having a super tweeter:

I think I can recommend this new driver - at $23 it's a bargain.

 

[freddi]

yes - that's quite even coverage - nearly perfect - re:dip - there may be a combination of dimensions to avoid/reduce it - in practice I think the only time it would be a problem would be when sine is applied at the dip frequency. Can you hear "it"? btw - I'm looking for a higher efficiency tweeter to use behind a K-slot - haven't yet measured a GRS 1005 - a transformer would bring nominal sensitivity of a 0.13uF piezo up to around 103dB at 2.8v - I'm not sure what happens when the wavefront from a little round horn hits a K-slot.
Also, I'm looking for a K-slot midrange with high 90's tp 100dB sensitivity.

what might the K-slot do to CHN-50's elevated area?

 

[xrk971]

I can't hear the dip at 2.4khz when listening to music. It is there when the sine sweep is performed of course. 2.4kHz corresponds to 2.8in which may be the distance from cone to K wing. Perhaps some damping pads glued to backside of K aperture? Even though the XKi was tuned for the RS100, it performs very well with the PS95. Clearly audible 60Hz bass extension. The higher Qts and larger Vas means the cabinet could be bigger and the bass SPL might be brought up a bit. The super tweeter effect is nice - not fatiguing as above 10kHz.

The CHN-70 is too big to put in the same box, besides the Vas is much bigger and means a new box will be needed. I would imagine the 600Hz to 7kHz plateau might be somewhat smoothed but I fear the amplitude may actually increase. That would sound worse.

 

[xrk971]

XKi with 3FE22r16

I stuck the 16ohm 3FE22's in the same XKi cabinet and it worked almost as good as the PS95's. Less bass but the output above was very smooth. Again, the polar response uniformity is exceptional.

Here is polar response, again 5dB variation over 45 deg at 10kHz:

For comparison, here is what the polar response of the 3FE22r16 looks like in an open face Nautaloss:

Here is the frequency response and harmonic distortion. I think there is a loose screw on the K-aperture that cause a rattle which shows up at 300Hz-400Hz:

I definitely think that if you are looking for a speaker with a wide sweetspot, this is it. For example, a speaker for listening in the kitchen or workshop where you are walking around and want the sound to be uniform.

 

[freddi]

at some point you might give this its own little thread with a catchy title touting its relatively wide and even horizontal dispersion up to 10KHz and beyond. Besides being good for areas where people are moving, that evenness can sometimes be an advantage for those seated. The builds would be inexpensive and fun for some people. Would the 2K2 dip look the same if the cabinet is tilted so the baffle is perpendicular to the floor? - guess that's a silly thing to think when the mic could be moved.

 

[Barleywater]

I stuck the 16ohm 3FE22's in the same XKi cabinet and it worked almost as good as the PS95's. Less bass but the output above was very smooth. Again, the polar response uniformity is exceptional.

Here is polar response, again 5dB variation over 45 deg at 10kHz:

For comparison, here is what the polar response of the 3FE22r16 looks like in an open face Nautaloss:

Here is the frequency response and harmonic distortion. I think there is a loose screw on the K-aperture that cause a rattle which shows up at 300Hz-400Hz:

I definitely think that if you are looking for a speaker with a wide sweetspot, this is it. For example, a speaker for listening in the kitchen or workshop where you are walking around and want the sound to be uniform.

What are phase responses for these two enclosures?