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

[freddi]

Here's tuning for XRK971's single PA130-8 XKi when made of 9mm plywood:

 

[freddi]

Hey X - What was your Beta8cx XKi's tuning ? I'm worried mine are tubed too low and can't be modified. As built by my friend with a long tunnel vent and tight aperture comes in @ ~60Hz - which is well below a target of around 70Hz - then again that may be acceptable as GregB's Karlsonator 8 tuned around 41Hz.

 

[freddi]

I'd like to add my "boombox" made of two PA130 XKi that sit on a carrier has very good sound with a $20 or so Kinter 3118 12 volt supply amp and its tone controls are useful (plus can bypass). It was a total success.

A 10 inch XKi ("Tiny 10") built by a friend has not proven itself yet. Loaded with a Tymphany "pro" 10" woofer, its pink noise graph doesn't even reach 100Hz - and is beaten by an Alpha 10A. The rear chamber is only about 25 liters - but that should be sufficient - with some 10" speakers such as Delta 10A.

Bandpass sim were too optimistic for LF extension - dunno about those pink noise graphs .

If I get this cabinet then will try a couple of different 10 speakers and bass guitar.

 

[freddi]

I'd like to add either a Kube15 or Kube18 in place of Kube12 for higher output capability - and keep sensitivity near 98dB + or so 1W/1M

 

[doug01n]

XKi with A6



Here is the design for an XKi with the A6p:

6in Wide x 10in tall x 6.3in deep (all internal dims) with a 6in wide x 0.5in tall x 11in long vent. Total active volume (front and back) is 5 liters. Make the triangle front chamber 2.5in deep from front. Use 1/2in plywood.

Here is SPL at 2.83v (fb is about 67Hz):

Here is Impedance:

Here is cone displacement at xmax of 5mm and 8,3v drive:

Here is max SPL - about 100dB at 8.3v:

Would it work with the Alpair 5.3?
I have one on the way to a project, and it would be very cool to test it with a full printed version of the XKI. My printer have a build plate for 22cm x 22cm x 250cm, and would be great to fit in one print.

 

[msegel]

This was made in my usual spot inside my lab on top of a 30in tall stool about 3.5ft away from back wall. Mix was about 36in high off the floor. So there are walls for sure but mix is 0.5m away so helps to reduce ceiling and floor bounce.

It’s been a while but I think the above is with EQ applied. Here is difference between raw (red) with high pass filter (green) and with EQ (blue):


Here is typical photos of the setup (different speaker but similar setup).

View attachment 1189815

Hi,

I've kinda started to jump thru this thread.
I saw earlier someone posted about using a B&C 8CXN51 driver.
While a full range, it tops out around 18kHz. (70Hz - 18kHz)

Here you're showing the Tang Band 8" Coax. (Parts Express lists it but you need to buy 50 of them before they'll order it in. )
Got to ask... How would the Tang Band Coax do in this box? I forget the specs but if memory serves. 38Hz to 40kHz.
You'd have to put in an XO ... something around 1.1kHz???

PE recommends a vented cabinet of ~1cubic ft or ~28L

Thoughts?

 

[xrk971]

If you use the Tang Band W8-2314, I have a crossover for it and it would work great in an XKi.

 

[msegel]

Thanks for the response...
I don't have anything yet... I'm kicking the tires... waiting for April to see what new at AXPONA. (I live in Chicago so its a short drive... in traffic)

The larger problem w Tang Band, that coax isn't available at Parts Express unless you want to buy 50 of them. I believe they are the only suppliers in the US?

-Mike

 

[xrk971]

You can get them from Europe. About $300 though - not inexpensive. But it’s a special sounding driver.

https://www.ebay.com/itm/1740058551...Y9mcKZ3Rq-&var=&widget_ver=artemis&media=COPY

 

[freddi]

my kid is using the PA130 XKi with a cheap but cheerful Kinter 3118 amp (~$23 !) with his laptop - its really impressive. Do the double driver XKi sound as good/clear as single driver versions?
- A double driver PA1330 - or double Beta8A with K-tube could be pretty powerful. How should the doulbe Beta8A be done?

 

[msegel]

You can get them from Europe. About $300 though - not inexpensive. But it’s a special sounding driver.

https://www.ebay.com/itm/1740058551...Y9mcKZ3Rq-&var=&widget_ver=artemis&media=COPY

Ok,
So I went to AXPONA yesterday. Stopped by the Parts Express room. Talked to one of the guys...
Seems that sometimes Tang Band can be hard to work with. I get that... Sometimes its hard to work w manufactures who have their agenda and vendors have to face the market ... Not sure I'd buy from E-Bay... would rather pay shipping from Europe. But still while they seem interesting... going w a 2 way tweeter/ woofer may make more sense.

I did like the guys from Madisound and from Parts Express. I'd rather buy from a store where there's customer service.

Since I'm really only planning on building one or maybe two sets of speakers... Going w a kit may be safer. Or if I do go Co-Ax or full range... look at a different speaker.

 

[SredniVashtar]

my kid is using the PA130 XKi with a cheap but cheerful Kinter 3118 amp (~$23 !) with his laptop - its really impressive. Do the double driver XKi sound as good/clear as single driver versions?

I haven't made a single PA130 so can't compare. I think the doubles I made were tuned a little deep. I had to get rid of them when I moved country so am looking at building another pair. If I recall correctly, the Akabak simulation did not account for the right angle bend in the duct and the end effect at one end of the duct (maybe both ends). Both of these serve to increase the effective length of the duct, making it tune too deeply. There was a dip in bass response at about 80 Hz, which picked up below 60 Hz. On some music they sounded amazingly clear and deep.

 

[freddi]

I have some XKi8 - target tuning was around 70Hz" but shelf vent effect plus front aperture plate which effectively lengthens the duct gave tuning at 60Hz- with Eminence Beta8a it plays into the 40's - a good octave deeper than a K12.

It would be interesting to see if NEXO's K-slotted shelf vent concept would work in some XKi which use a relatively long shelf vent. "Gridnstone" posted a picture of a NEXO cabinet

XKi8 with 9 inch long K-tube

 

[L.rivera92172]

A 9in k tube how low does it play too is it a 1in exit I wish I can get a pair

 

[freddi]

not sure how low- - it sounded strong on sine sweeps - beautiful on handbell recordings with a PRV D260 ring radiator compression driver. It was printed for me by Pelanj - so the file may be in one of his folders - if not- I'm sure he could provide it.

 

[freddi]

here's a file for a 9 inch long tube - would not attach at first = message too long

worked this time - I'd like to get some spares printed - if printing costs and shipping isn't too high.

 

[L.rivera92172]

Ok thanks I try asking him

 

[L.rivera92172]

Oh you sent it thanks