Jump to content
The Klipsch Audio Community
Sign in to follow this  
djk

PPSL Vented LaScala

Recommended Posts

DJK, as Sargeant Schultz would say "VERY INTERESTING"!

I've got 8 8" Pinnacle subs laying around with poly cone and butyl surrounds with 31Hz fx, .27 qt, .29qe, 56lit vas, 89db 1w/1m, and revc 6.2 ohms. 4db less sensitivity than the Silver Flutes. Any idea how these puppies would work in this application? Thanks.

Share this post


Link to post
Share on other sites

The poor LaScala. It seems its always being bastardized with an idea of some magical Swan Song Bass mod. I can surely appreciate everyone looking for a clear breakthrough in performance and keeping the low distortion, but somewhere PWK has to be smiling at all these attempts that never are a clear winner above his original design, given the cabinet space.

Edited by Max2
  • Like 1

Share this post


Link to post
Share on other sites

Good engineers design to goals that include, among other things, ease of production and cost of production, as well as performance. PWK was an excellent engineer.

DIY folks are not constrained by ease or cost of production. There are many tweaks that can be done to PWK's designs that will produce improvements in frequency response, distortion, efficiency, etc.  To think that if PWK didn't put it into production it's not worthy of consideration by a DIY enthusiast is shortsighted.

GM intended the Roots-type blower for diesel engines in high altitude applications, not to supercharge an engine that Chrysler designed for use in DeSoto sedans. It took hot rodders to squeeze the most out of that combination. Audio has hot rodders too.

YMMV

Share this post


Link to post
Share on other sites

Good engineers design to goals that include, among other things, ease of production and cost of production, as well as performance. PWK was an excellent engineer.

DIY folks are not constrained be ease or cost of production. There are many tweaks that can be done to PWK's designs that will produce improvements in frequency response, distortion , efficiency, etc.. To think that if PWK didn't put it into production it's not worthy of consideration by a DIY enthusiast is shortsighted.

GM intended the Roots-type blower for diesel engines in high altitude applications, not to supercharge an engine that Chrysler designed for use in DeSoto sedans. It took hot rodders to squeeze the most out of that combination. Audio has hot rodders too.

YMMV

The K-horn cab has to be one of the most sophisticated builds out there and a tough one to actually get correct, when it comes to production speakers. Now back to the LaScala, I applaud all the guys out there looking for improvements and a real break through, IMO, nothing has been a clear winner yet. I like your blower reference, it is a good point and shows how not only application uses have changed, but rotor designs have been improved much with new helical rotor designs. However, the LaScala is still the LaScala and just like anything else, if there was some sort of mod that actually made sense, wouldn't we would all be doing it?

Edited by Max2
  • Like 1

Share this post


Link to post
Share on other sites
if there was some sort of mod that actually made sense, wouldn't we would all be doing it?

No, because the majority of people believe something bad will happen if they do anything more than hook up a pair of wires to the speakers. But there exists a small group of people, some with an Engineering background, like myself, that like to make some "tweaks" to please their ears and/or measuring instruments.

As a kid, I built various speakers for 10 years until I could afford Khorns and LaScalas. Lest you think I was being cheap, I used high priced Altec and EV components at my zenith right before the Khorn purchase, which I had to take out a bank loan to do out of college. My quest was over while I raised my kids. Now that has been done for a while, it's been tweakersville for me and the sound I have is better than it ever was with vanilla Khorns, although I still have 80% Klipsch in my sound.

I think John Warren has some of the best Khorn mods, along with Al Klappenberger, Volti, Fastrac, and others who poke their heads in this community once in a while.

Edited by ClaudeJ1
  • Like 1

Share this post


Link to post
Share on other sites

"The poor LaScala. It seems its always being bastardized with an idea of some magical Swan Song Bass mod. I can surely appreciate everyone looking for a clear breakthrough in performance and keeping the low distortion, but somewhere PWK has to be smiling at all these attempts that never are a clear winner above his original design, given the cabinet space."

Well spoken for someone that has not heard it, and probably has no real understanding of the ideas involved.

"Any idea how these puppies would work in this application? "

May be too low in efficiency, especially since they are 8Ω

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the response DJK. I thought the efficiency may be too low. So would it be around 4db less efficient - around 100db horn loaded?

Share this post


Link to post
Share on other sites
The K-horn cab has to be one of the most sophisticated builds out there and a tough one to actually get correct, when it comes to production speakers.

Which is why the preferred bass bin to fit in a corner is the Jubilee. Easier to build and far superior.

Edited by ClaudeJ1

Share this post


Link to post
Share on other sites
The K-horn cab has to be one of the most sophisticated builds out there and a tough one to actually get correct, when it comes to production speakers.

Which is why the preferred bass bin to fit in a corner is the Jubilee. Easier to build and far superior.

I don't know. I like your Q-Pie. It could be a contender...

  • Like 1

Share this post


Link to post
Share on other sites

"The poor LaScala. It seems its always being bastardized with an idea of some magical Swan Song Bass mod. I can surely appreciate everyone looking for a clear breakthrough in performance and keeping the low distortion, but somewhere PWK has to be smiling at all these attempts that never are a clear winner above his original design, given the cabinet space."

Well spoken for someone that has not heard it, and probably has no real understanding of the ideas involved.

"Any idea how these puppies would work in this application? "

May be too low in efficiency, especially since they are 8Ω

Forgive me djk. I didn't mean to belittle your experimentation and design in your thread, which I sort of did in a knee jerk response.

Edited by Max2

Share this post


Link to post
Share on other sites

Good engineers design to goals that include, among other things, ease of production and cost of production, as well as performance. PWK was an excellent engineer.

DIY folks are not constrained by ease or cost of production. There are many tweaks that can be done to PWK's designs that will produce improvements in frequency response, distortion , efficiency, etc.. To think that if PWK didn't put it into production it's not worthy of consideration by a DIY enthusiast is shortsighted.

GM intended the Roots-type blower for diesel engines in high altitude applications, not to supercharge an engine that Chrysler designed for use in DeSoto sedans. It took hot rodders to squeeze the most out of that combination. Audio has hot rodders too.

YMMVThey did

Roots blower is needed to fill the cylinder of 2 stroke deisels at any altitude. The engines would not work without them. I agree with every thing else though.

Share this post


Link to post
Share on other sites

I hate to drag this thread back up again but wouldn't this design be limited in top end bandwidth due to the plenum dimensions. Maybe resonances around 200 or 400 Hz ?

 

Thoughts ?

Thanks

Share this post


Link to post
Share on other sites
On 3/18/2014 at 1:25 AM, mustang guy said:

I don't know. I like your Q-Pie. It could be a contender...

Thanks, but trumpeting my own, highly modified "simplified, baby MWM" design would be too self serving, even for the dyed in the wool audio tweaks. But I do agree with you. LOL.

Share this post


Link to post
Share on other sites

"I hate to drag this thread back up again but wouldn't this design be limited in top end bandwidth due to the plenum dimensions. Maybe resonances around 200 or 400 Hz ?"

 

The limit for a properly built PPSL with 8's is about 500hz (due to the depth).

 

I am going to have to have a custom driver designed, the SEAS originally used was a surplus custom driver, not a stock driver, and is NLA.

 

The Silver Flutes had too low of a Qts, and are NLA anyway.

 

I am going to do a video at some point to hear the difference the PPSL makes, you have to hear it to believe it.

 

(access is limited to the speakers involved due to personal issues involved in the couple that own them (not me)).

 

While I recently bought a house, and planned to build a golden-mean listening room, buy a videocam and post the results, it is not coming together as fast as I would like.

  • Like 1

Share this post


Link to post
Share on other sites
4 hours ago, djk said:

"I hate to drag this thread back up again but wouldn't this design be limited in top end bandwidth due to the plenum dimensions. Maybe resonances around 200 or 400 Hz ?"

 

The limit for a properly built PPSL with 8's is about 500hz (due to the depth).

 

I am going to have to have a custom driver designed, the SEAS originally used was a surplus custom driver, not a stock driver, and is NLA.

 

The Silver Flutes had too low of a Qts, and are NLA anyway.

 

I am going to do a video at some point to hear the difference the PPSL makes, you have to hear it to believe it.

 

(access is limited to the speakers involved due to personal issues involved in the couple that own them (not me)).

 

While I recently bought a house, and planned to build a golden-mean listening room, buy a videocam and post the results, it is not coming together as fast as I would like.

Thanks for responding.

 

These silver flutes? (they are available) https://www.madisoundspeakerstore.com/approx-8-woofers/silver-flute-w20rc38-04-ohm-8-wool-cone/ . The actual  measured Qts "MAY" be a bit higher.

 

Not sure exactly what T/S specs I'm looking for, . but might these work (in theory)?

http://www.parts-express.com/dl840-4-8-heavy-duty-treated-paper-cone-woofer-4-ohm--299-2174

 

http://www.parts-express.com/tc-8034-8-treated-paper-cone-woofer-with-foam-surround-4-ohm--299-2200

 

http://www.parts-express.com/visaton-w200s-4-8-woofer-with-treated-paper-cone-4-ohm--292-570 ( a bit costly considering I would need 8 of these)

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...