2-way with a 511/902

[PrestonTom]

I am dreaming of a project for next year (after the batroom is re-done and the back of the house gets painted, etc).

I have become intrigued with a 2 way & time aligned horn loaded cabinet.

May question is two part.

Should I mod my K-Horns and make them 2 way (others have done this with their La Scalas). The possible plan is to make a replacement HF cabinet (I currently have a KCBR, so matching the wood be easily done) so I could sell the old ones if need be. Additionaly I would be moving to an outboard crossover with "steepish" slopes. I would cross at about 400Hz and also use time-alignment (and bi-amping). The adjustable crossover with time alignment is one of the real attractions of this possible project.

My First Question.

I assume the parts would be 511B horns and a 902 driver.

1. Is this the 902 8B driver the correct one. Do these always come with the Loading cap installed (I assume this is to limit excursion). I assume they directly bolt together or a simple adaptor is available.

2. Does the 902 need a fancier diaphragm to get the HF extension (17kHz is sufficient as a half power point).

3. What is the actual efficiency (I believe the 106dB listed is measured at 30 ft or something, I may have mis-read it).

4. If I try and get the driver to go down to 400Hz (not the listed 500Hz) and high-pass with a steepish filter, what probelms will I run into. IOW try to extend it to a lower frequency could potentially damage the driver, but is there an issue of distortion also? I mostly listen to classical and old jazz, but ocassionally I may crank up some rock from my mis-spent youth.

5. Would the depth on the horn & driver be too long to fit into the cabinet?

6. Does the 511/902 get excessively "beamy" in its dispersion if you try and make it go that high in frequency.

My Second Question.

What are the pros & cons of simply building (famous last words ...) a Jubilee bass bin and use its higher frequency extension (and lower distortion). I would still continue with the 511/902 as the upper section and cross them at a higher frequency. Now this would be an exciting project!

Price is a factor, so simply geting a Jubilee is not on the table. Also the HF section on the Jub is also pricey and far too large (my girlfriend would kill me). Seeing the sectorial horn of the 511 will already drive her close to the edge.

1. If one did build a Jub bass bin, which one? Has anyone actually tried the version with the passive radiator? Much of the discussion seems to center on the version from the AES article and that ended up being used in the commercially available Jub cabinet.

Your collective thoughts are appreciated. I suspect some of you are already thnking along the same lines, so I hope this thread is helpful to a number of us.

-Thanks,

-Tom

[Duke Spinner]

ifn' ya want 2 way, horn loaded and time aligned .....

..............VOTT

[]

[IB Slammin]

ifn' ya want 2 way, horn loaded and time aligned .....

..............VOTT

[]

Must agree with the Dukestir, but with Klipsch bins.

Tom, Will get back to you with my inpressions having run 511/902 for a few years in three way and then trying it two way. Have a game to play at this time.[li]

GO HOGS GO !!!!!! SEC!!!!!!

[jwc]

Tom,

I can't really answer alot of your questions. However, your interest parallels mine.

I currently run the 902 8B's on the 511's. These are roughly crossed at 400Hz with 1st order but rolled off at 6000Hz. Running three way with jbl 2404. Now this setup is on my dbb's not a Khorn.

Now I can say with some confidence that the 902 will do fine crossed at 400Hz as myself and Terry are doing it now. However, we both run 3 way. He has tried the two way....I haven't.

Those people out there who have the 902 incorporated into ther Klipsch Heritage may not realize that they are running the 902 from 400Hz all the way out to 20,000Hz. Most of the PWK vintage networks have no band pass on the midrange and just expected the K55 to roll off on its own. I only bring this up because from a "blowing the driver standpoint", the 902 seems to stand up pretty well (non commercially-non pro setup).

Now I am doing just what you have brought up about the Jubilee. I believe you contribued to my "Bass horn thread". One I have the first clone jub bass bin built, it will be mated with the Altec511 and 902 (heresy!). HOWEVER, I will initially run it three way just like I do now with my dbb's. I may find that the jub may not be to my liking as much as I like my dbb's. I therefore will either ditch the jub idea or either build a 15" driver version or port the dual 12" driver like the home jub version was meant to be. The latter will be difficult as there will be a lot of guess work. Not sure I am capable of figuring it out. Speakerfritz I believe has the ported version in mind if he could get his other projects out of the way. I also am not aware if someone has built one yet besides Roy and PWK.

jc

[IB Slammin]

ifn' ya want 2 way, horn loaded and time aligned .....

..............VOTT

[]

Must agree with the Dukestir, but with Klipsch bins.

Tom, Will get back to you with my inpressions having run 511/902 for a few years in three way and then trying it two way. Have a game to play at this time.[li]

GO HOGS GO !!!!!! SEC!!!!!!

.......In reality .....we suck this year too......

[Dylanl]

Don't most active crossovers give you the ability to time align? If so that would be a quick fix.

[IB Slammin]

Tom,

What JC said.

The 902 handles a +/- 400hz cross with ease, even in 1st order. (as long as the plug in)

Not sure that I gave it a valid shot in two-way. Didn't use it that way for long. Could be the room, or could be me, but I needed a little more sparkle at the top.

Terry

[BEC]

Terry,

Did you try taking your hat off for a little more sparkle on top?

Bob

[IB Slammin]

Terry, Did you try taking your hat off for a little more sparkle on top? Bob

That really hurt Bob.[:'(] You know that Fini wouldn't take a cheap shot like that.

Terry

[PrestonTom]

Tom,

I can't really answer alot of your questions. However, your interest parallels mine.

I currently run the 902 8B's on the 511's. These are roughly crossed at 400Hz with 1st order but rolled off at 6000Hz. Running three way with jbl 2404. Now this setup is on my dbb's not a Khorn.

Now I can say with some confidence that the 902 will do fine crossed at 400Hz as myself and Terry are doing it now. However, we both run 3 way. He has tried the two way....I haven't.

Those people out there who have the 902 incorporated into ther Klipsch Heritage may not realize that they are running the 902 from 400Hz all the way out to 20,000Hz. Most of the PWK vintage networks have no band pass on the midrange and just expected the K55 to roll off on its own. I only bring this up because from a "blowing the driver standpoint", the 902 seems to stand up pretty well (non commercially-non pro setup).

Now I am doing just what you have brought up about the Jubilee. I believe you contribued to my "Bass horn thread". One I have the first clone jub bass bin built, it will be mated with the Altec511 and 902 (heresy!). HOWEVER, I will initially run it three way just like I do now with my dbb's. I may find that the jub may not be to my liking as much as I like my dbb's. I therefore will either ditch the jub idea or either build a 15" driver version or port the dual 12" driver like the home jub version was meant to be. The latter will be difficult as there will be a lot of guess work. Not sure I am capable of figuring it out. Speakerfritz I believe has the ported version in mind if he could get his other projects out of the way. I also am not aware if someone has built one yet besides Roy and PWK.

jc

JC,

Thanks for your input. Keep all of us posted. I suspect there could be a great deal of interest in this.

-Tom

[PrestonTom]

.......

Tom, Will get back to you with my inpressions having run 511/902 for a few years in three way and then trying it two way. Have a game to play at this time.[li]

.....

Thanks,

I am interested in your thought on this. Given the reported bandwidth of the 511/902, I can not imagine why one would not go with it as a 2-Way. Is there a possibility of distortion or some problem with dispersion when you run a 511/902 uo to the "tweeter range"?

-Tom

[chops]

Yes, the 902-8B is the correct driver of choice, yes 106dB @ 1W/1M with 511B is correct, yes, I think that most all 902 drivers come with the loading caps installed, there is no adapter needed to mount the 902 to the 511B horn.

If I had to choose between the KHorn bin and Jub bin, I'd go with the Jub, and I will tell you why.

Since the Jub bass bin will get you a little added HF output from the woofer(s), you can cross the 902 drivers higher. As others have mentioned here in other threads and on the Altec User's board, the more you ask the driver to produce lower midrange, the faster it seems to roll off the top end. I'm not exactly sure why or how it does this, but it's true as I have tried many crossover points via my Rane AC-22B. From a range between 400-800Hz, I have found that 600Hz (measured roughly 625Hz through TrueRTA) provided the best possibly midrange sound and from 600Hz on up, the HF output seemed to level off with no real added output above the 600Hz point.

Also, I know people cross the 902/511B rather low. I've read somewhere as low as 365Hz, 2nd order. From playing around with x-over freqs, it sounds to me that the 902 fails to load the 511B horn properly below 500Hz (500Hz being the limit) and the lower midrange begins sounding a little odd. TrueRTA showed some pretty bad jagginess when crossed below 500Hz, and worse the lower I went. However, things seemed to smooth out at 600Hz.

And as for beaminess, I don't hear it at all. Again, it might have something to do with my room and layout, but HF dispersion from side to side seems to be pretty uniform throughout the room. The thing I have noticed about beaming is that these horns don't like to disperse HF energy vertically. I have the horns tilted down to ear level, so when I'm seated in the sweet spot everything sounds fine, but if I stand up, the HF tends to roll off a little. Nothing drastic mind you, but clealy noticable.

The time delay is another one that I would rather be able to adjust on the fly. I never knew it before, but the time alighnment changes with the crossover frequency, so once you figure out the distance between the woofer and 902, you still have to adjust for whatever x-over freq you choose. Even then, there's no set rule as to what will be correct, only guidelines to get you in the ballpark. I had to fine-tune with TrueRTA and lastly/mostly by ear. And you'll know when you get the time delay just right as everything (voicing, imaging, soundstage) will just snap right into place.

I too wouldn't mind going for full-fledged VOTTs, but if space is a concern and you think the KHorns are large, take a look at the A7 bass horns sometime. They're not exactly small. If I had a pair in my room, they would overlap my 9' screen by about 6" on either side, and that's with the cabinets up against the side walls where the CWs are now.

[jwc]

Charles.

I think your "logic" of crossing the 902 higher on the low end at 600 allows better response on the high end is good logic. I have heard this before on more than one occasion.

I think Altec's new A7 has the 902-8T crossed at 900Hz.

As you know, I run the 902-8B/511 three way with a JBL tweeter. Passive. Crossed 1st order at around 400Hz and rolled off at 6000Hz. I had thought that I RTA'ed it but I can't seem to find the file.

At any rate, I think with my setup, the 511 combo with the 902 sounds great at the low mid frequencies. Again, not going out to 20K. So I personally think (no objective proof right now) that the above combo works at the low frequencies but may not do as well with going out to 20K

I'm sure you have seen this before as this is ALK's plot of the 511, Trachorn and K400 with a K55. Now this only proves that the 511 itself is capable of handling down to 400Hz.

Just food for thought. Eventually will give the two way option more of a try later.

jc

[PrestonTom]

I have seen that graph before of the different horns driven by the same K55 driver (it is not clear if this is a K55 or a K55V or K55M driver, I will assume it is the first). Obviously this can not be used in a 2-Way configuration (my ears are not that old).

I get confused when I trace the curves, but the 511 does look better than the K400. I am not sure it looks that much better at the low end however. The take home message appears that the HF extension is determined by the driver and not the horn. Let me phrase it another way what are the half power points of a K400 (or 401) horn with a 902 driver. I have to beleive that someone has tried this before. It would be such an obvious and simple way to convert a K-Horn to a 2-Way.

I must be missing something.

-Tom

[jwc]

Tom yes. The purpose of me posting that image was to show off the low end midrange only. That is a K55V and it rolls off on its own at 6000 w/o a network.

Now I have no experience with this but here is my OPINION.

You could just strap that 902/511 combo on the khorn and do it two way and cross at 400Hz. Please Don't blame me if it blows but I honestly think you could try it out and listen at low levels to try it out. I wouldn't be afraid to do it. I've had the guts to try out all kinds of stuff.

I do think that with that broad frequency range, there will be some "sweetness" lost at the extreme hi and low ends.

Again IMOO

jc

[IB Slammin]

Tom yes. The purpose of me posting that image was to show off the low end midrange only. That is a K55V and it rolls off on its own at 6000 w/o a network.

Now I have no experience with this but here is my OPINION.

You could just strap that 902/511 combo on the khorn and do it two way and cross at 400Hz. Please Don't blame me if it blows but I honestly think you could try it out and listen at low levels to try it out. I wouldn't be afraid to do it. I've had the guts to try out all kinds of stuff.

I do think that with that broad frequency range, there will be some "sweetness" lost at the extreme hi and low ends.

Again IMOO

jc

......... Please Don't blame me if it blows............

Let-er-rip at 400hz Tom. I have some NIB 8ohm diaphragms if you need them. If they hold up for me......they will hold up for anyone[].....(In home use that is)

tc