KPT-904 as a 3 way, which xovers and horns?

[mustang guy]

I am considering replacing my front 3 LaScalas with 3 KPT-904's, and my 2 THT's with KPT-684's. I have the 904 bass bins, but no networks or horns. Rigma mentioned that there was somebody in this forum who had great success with this mod. I'm not sure if they used the crossovers and horns of the Jubilee 535. It seems to me that the 904 bass bin would have trouble keeping up with the jube bin, but I'm unsure.

Can somebody guide me as to what configuration I would need?

[bhendrix]

Hi Mustang Guy,

I'll give it a shot, having owned all three, but in two-way configuration. I'm not sure exactly what you mean by the KPT-904-LF having trouble keeping up with the KPT-KHJ-LF (Jub).

Here are some specs:

KPT-KHJ-LF - sensitivity 105db, -10db at 34Hz (half-space, I believe)

KPT-904-LF - sensitivity 104db, -10db at 32Hz (half-space, I believe)

LaScala LF - sensitivity 104db, -4db at 53Hz (not sure whether half-space or 1/8th space)

As you can see, all three will play equally loud with the same input. The Jub and the LaScala will have the wicked-fast, low-distortion, horn-loaded character. The 904 is a bass reflex. The difference between the 904 and the Jub will be somewhat similar to the Cornwall (bass reflex K-33) vs the K-horn (horn-loaded K-33).

With active EQ, the Jub LF response can be improved somewhat with minimal increase in distortion.

My experience with the HF side is limited to K-402 and K-510 horns (lenses) and the K-69 and KDE-75 (B&C DE75) drivers, all in two-way configuration.

The 402 is the better of the two horns, but the 510 is no slouch. The 510 is excellent.

The KDE-75 is the better of the two drivers by a fairly significant margin, imho.

The configuration you "need" will depend on a number of variables including, but not limited to:

WAF, Budget, Active vs passive, size and configuration of listening space, etc.

My Jubs (402 w/ k-69) were powered by Crown XTi 1000 with active EQ, delay, and crossover.

My 904s (510 w/ KDE-75) are powered with a simple Denon receiver and sound fantastic. The 904s use the simple, 4-component, 12db/oct crossover that came with them in 1999.

The HF sections of both options will run 3-4db hotter than the LF. You can compensate with active EQ or, as I discovered, the Audessey XT-32 in the Denon recognized the hotter HF and compensated automatically. It's magic!

[mustang guy]

Thanks for your response. My Integra DHC-80.3 has all the modern Audessey suite including the X-32. What I don't have is the 904 crossover, as my 904 is not the "N" model. I can bi-amp the mains with this pre-amp, but not the center. This seems odd, as it implies that Onkyo must not think timbre matching is all that important. Finding a processor for the center which is identical to the one used in the integra for the bi-amping the mains would be impossible. I cannot understand why they wouldn't provide a way to also bi-amp the center channel. I am only using 3 of the 9 channels of my Integra DTA-70.1 amp, so I could find a processor to go between my pre-amp and amp which could split the signal and allow me to bi-amp

I am getting to the point where I think I might leave well enough alone. The 904 isn't going to outperform the LaScala in any way except max volume. In fact, the LS may be better in every way except max volume.

[Speakmeister]

The 904 isn't going to outperform the LaScala in any way except max volume. In fact, the LS may be better in every way except max volume.

I think most that have the KPT-904 will disagree with that statement. I for one own both and think the 904 out performs the LaScala by a significant margin. It is well worth the time to set the 904 up properly. Many hours were spend dialing mine in and the results are very pleasing.

[bhendrix]

The 904 isn't going to outperform the LaScala in any way except max volume. In fact, the LS may be better in every way except max volume.

I think most that have the KPT-904 will disagree with that statement. I for one own both and think the 904 out performs the LaScala by a significant margin. It is well worth the time to set the 904 up properly. Many hours were spend dialing mine in and the results are very pleasing.

+1 on the disagree

Sent you PM, MG

[Marvel]

If you are talking about the LS in your HUGE room, compared to the 90s in the same room, I would take the horn loaded bottom end, even if the response of the 904s is lower in freq.

[davis419b]

I am getting to the point where I think I might leave well enough alone. The 904 isn't going to outperform the LaScala in any way except max volume. In fact, the LS may be better in every way except max volume.

Had you heard the 904,s when you made this statement ?

[mustang guy]

I am getting to the point where I think I might leave well enough alone. The 904 isn't going to outperform the LaScala in any way except max volume. In fact, the LS may be better in every way except max volume.

Had you heard the 904,s when you made this statement ?

Nope

They are still on the trailer. I was jumping to uneducated and unfounded conclusions. []

Thanks for all the feedback folks! This space is indeed huge. The listening area is 50' wide by 60' deep, with 24' ceilings.

I could build a private theater with all the stuff I have. It may sound crazy, but the theater here in Parkersburg is awful. It's out of focus, the seats are crappy (non-stadium), overpriced, and the sound is absolutely pathetic. We drive 40 miles to go to the movies in a whole different state. It is sad.... []

It would be awesome to install about a 20-30 seat theater into a vacant store or something. I would just have to find a distressed property for cheap, and start acquiring all the things I would need. Perhaps in a year, I could put the puzzle together. Who knows??

[IB Slammin]

I am getting to the point where I think I might leave well enough alone. The 904 isn't going to outperform the LaScala in any way except max volume. In fact, the LS may be better in every way except max volume.

Had you heard the 904,s when you made this statement ?

I have heard the 904's in two way with the K402 horn. I am a reflex guy but didn't like them very much. I would keep the LaS. JMHO.

tc

[mustang guy]

I am going to test the bass bins, and if they are sound (pardon the pun), I might order the KPT-904-HF's, and order some parts for the simple network from BEC. I would try them in place of the LS's, and if they don't sound good, I will list them for sale for about $1,000 each. The HF's cost about $650 ea new from the cinema dealer. In fully restored condition, with brand new networks and brand new top-horns, they should be worth that. KPT stuff hardly ever hits Ebay, and when it does, it usually gets a lot of attention.

[ZombieWoof]

so are you out to flip them ? Or keep them if they sound good ?

Wow I'd love to find a set like them ,I'd bet they would sound great with Dave's ElipTrac as a HF horn & a decent compression driver

[Guest " "]

Standard solution for 3 way KPT-904 is the KPT-535 top section which consist of a k-510 horn with a k-69 driver and a 70X horn with a k-70-g driver. comes with a passive crossover. The k-1133/32 driver would also work. and if the tweeter horn you want to use is 4 way bolt on instead of screw on you can use the k-71-G driver.

[Coytee]

I like that more & more are working their way into the big toys.

[Y]

[mustang guy]

Standard solution for 3 way KPT-904 is the KPT-535 top section which consist of a k-510 horn with a k-69 driver and a 70X horn with a k-70-g driver. comes with a passive crossover. The k-1133/32 driver would also work. and if the tweeter horn you want to use is 4 way bolt on instead of screw on you can use the k-71-G driver.

Sadly, I can't use the 535 way because the overall height is 81". The 904LF/HF way is only 55.5". As you can see in the pics, the LaScala at 35.5" I don't have the 45.5" needed for the 535 to fit. I would have to raise the screen by about 20", and that is something I don't want to do.

I have been thinking a lot about getting a larger screen. The one in the pic is 130". With some additional side framing, I could easily go 200", and that would be much more appropriate for seating back 20-30'.

[davis419b]

Why not just go 2-way ?

[mustang guy]

Why not just go 2-way ?

That is precisely what I intend to do with the 904HF. I know the 535 system would sound better and more like a LaScala on steroids, but I am not placing the speakers behind a screen, so I don't want the bottom of the screen to have to be 7' high. Actually, having the 904 horn at just below screen level should make movies more realistic than where the horns are on the LaScalas in relation to the screen.

[Y]

[davis419b]

I am getting to the point where I think I might leave well enough alone. The 904 isn't going to outperform the LaScala in any way except max volume. In fact, the LS may be better in every way except max volume.

Had you heard the 904,s when you made this statement ?

I have heard the 904's in two way with the K402 horn. I am a reflex guy but didn't like them very much. I would keep the LaS. JMHO.

tc

I have the KPT-904 with the 402/K69 horn and an active crossover that Rudy81 set up for me with 2 RSW-15's and I have yet to hear anything that sounds better to MY ears . Thanks Again Rudy ! My Jubilee's are sitting idle.

[mustang guy]

Can you tell me about the active crossover?

[Rudy81]

Don,

Glad to hear you are still enjoying the original setup. I know the RSW-15's put you in 'the zone' you were looking for. As you know, I have been become partial to direct radiators and the 904's are perfect for your room.

Unless it has been changed, we just set up a Behringer DCX-2496 as a three way, but not in the conventional sense. It is three way with the subwoofers picking up the low end. I have a similar setup at my place with the Oris horns, open baffle lower-mid bass and dual RSW-15's for the very low end.