K510 Jubilee little HF horn....

[sfogg]

The comparison setup. Run two way (with subs) in mono. Both upper
horns matched to .1dB using broadband noise from the horn itself as
measured by an Audio Control RTA-3051 with no weighting.

Also, as a side note... I tried to compare distortion between the two
drivers referenced to 88dB. The measurements I was doing were coming up
*identical* between the two drivers. Which leads me to believe I was
measuring the distortion of something else which was higher then
whatever the drivers were doing themselves. For example it could have
been the mic distorting..etc..etc. Which could mean my distortion
measurement shown earlier on the 44xt might not mean much.

Again by a couple of clicks on the mouse while
sitting at the listening position I am able to switch between the
K510/902 combo and the K510/44xt combo live while listening to music.

Shawn

[Bonder]

That's a scary set up there Shawn (in a good way)!! I can almost feel my chest compress just looking at those subs...

So how does the 902 compare? I've been trying to buy a pair of 902's on E-bay for the last month and keep getting shut out.... perhaps there's something better or easier to score?

[jacksonbart]

This is the K510 compared to an Altec 288 driver. It either shows how small the horn is or how large the driver is depending upon your point of view....

How much for that rug?

[sfogg]

This is the K510 compared to an Altec 288 driver. It either shows how small the horn is or how large the driver is depending upon your point of view....

How much for that rug?

$339 and free shipping if you use your L.L. Bean visa card....

http://www.llbean.com/webapp/wcs/stores/servlet/CategoryDisplay?page=braided-rugs&categoryId=39827&storeId=1&catalogId=1&langId=-1&parentCategory=4071&cat4=1151&shop_method=pp&feat=4071-tn

Shawn

[sfogg]

" I can almost feel my chest compress just looking at those subs..."

You can't see it but there is also a ContraBass subwoofer behind the screen. And all seats have 2 bass shakers in each of them.

"So how does the 902 compare? "

It doesn't, not on this setup at least.

I have a feeling the 902 doesn't play well with the 1" to 2" adapter and/or the K510. It sounds pretty much like it measures... pretty ragged and uneven. I don't know if it is simply the FR of that combo or if something else is going on (diffractions in the adapter?) but the K510/902 combo sounds very 'horny' and not in the fun way... in the honk kind of way. By comparison the K510/44xt sounds much smoother and more refined without the honk. It was so different I was wondering if something was going on in the horns. The horn that the 44xt was on had been smoothed by the metal mounting ring and the throat of the horn. The horn that the 902 was on had a sort of an edge from the horn sticking out over the mounting ring slightly. I was thinking maybe that was causing diffractions so I swapped the horn off the 44xt for another like the horn on the 902 but the 44xt still sounded smooth and refined in comparison.

I ran the same 902s on 511b for about two years and they didn't sound like that on that setup so I'd think it just doesn't like the adapter and/or horn.

Keep watching for the 902s. They come up enough that you should be able to grab a pair eventually. Also consider new drivers from Great Plains. They are basically 902 clones. Obviously they cost more but then you end up with known good drivers with brand new diaphragms. The diaphragms for the 902 are around $165 a pair so if you buy used and end up needing a pair you get pretty close to the cost of what new drivers from Great Plains would have cost.

Shawn

[Bonder]

Thanks for the feedback Shawn, appreciate the comments....

I have 511B's I'm using so I'm going to give those a try with the 902's.... if and when I try a K510 I'll look for a different driver [Y]

[sfogg]

I ended up ordering 2 more Peaveys which should be here in a couple of more days. Looking forward to getting all three front channels up and running with the K510/44xt.

Tonight I worked on getting the levels out of the Behringer proper for the K510/44xt to maximize SNR without clipping the DACs on the crossover while balancing the signal with the woofers. When I was testing the K510/44xt I was using a stock Teac which still had the input pots installed on it which were used to get the output levels fairly closely dialed in. The extra Teac allowed me to have both the old and new setups running to be able to switch back and forth easy to compare.

The efficiency of the 44xt itself is pretty close to that of the 288 but because of the EQ boost needed on the K510/44xt the output levels of the DCX at Ref. level would now clip where it wouldn't in the old setup before.

As such I figured I needed about 5dB more gain through the Teac. That would in turn allow me to turn down the output of the DCX by the same amount to keep relative driver levels the same but with more headroom in the crossover for the required EQ boost.

So I hooked up the stock Teac I was using to the analyzer and fed a 1kHz 1v RMS signal into it and measured its output in dBs on the analyzer. That gave me a baseline of where I was starting from. I wanted the gain for the K510/44xt channel in the modded Teacs to be basically 5dB higher then the baseline.

I had put fixed input attenuation on the modded units so each channel on each amp (each driver IOW) would be exactly matched while maximizing SNR out of the DACs. Also the operating parameters of the amps were changed to lower the amps self noise which also altered the gain (and max power) through the amps. Thread with info at:

http://forums.klipsch.com/forums/thread/652637.aspx

I ended up lucking out. After running the same measurements on one of the modded units it turned out one of the channels in the Teac ended up being 4.8dB higher in gain that the test amp was. So I didn't need to do any more work on the amps. I wired the K510/44xt into that channel and then dropped 4.8dB of signal on the output for that channel in the DCX. Acoustic levels matched up just right between the LaScala bass bin and the K510/44xt.

After that I spent the next hour or so trying different material to see how close I was to clipping on the K510/44xt output channel of the DCX. I got it to clip once or twice on very loud HF sound effects (EQ boost is highest at the top end) but it looks about right to me. I transfered the settings to the other DCXs so when the Peaveys arrive I pretty much just pull out the old drives, wire in the Peaveys and load different presets on the crossovers and I can start listening. The other thing I want to verify is how much power I'm using in the Teac's. The woofer channel has full power available (about 30w) but the noise mods dropped power for the K510/44xt channel to about 9w. 9w was plenty for the 288 but I want to be sure that ends up being enough power with the EQ boost on the 44xt. If not I can increase power (and need to rebalance levels) at the expense of a little more hiss.

Shawn

[sfogg]

Grrr... little hickup in the plan... one of the Peaveys arrived today.

The other one apparently never made it out of the warehouse. The place I bought them from generated a shipping label but it seems that Fedex never picked up the package. So of course the warehouse has to run a trace to see if they ever actually shipped the second unit or not which will take at least a few days and then about a week transit time to me. That is best case.

Meanwhile, expecting a pair of drivers today I already pulled apart my existing setup and shipped out a pair of tweeters.

So for a couple of weeks I'm either going to be running stereo up front with the K510/44xt and a phantom center or L/R K510/44xt with the old three way setup for the center. I am going to miss having the K510/44xt on the center as I have spent the last week or so just listening in mono with the K510/44xt there and it just sounds so good with vocals.

One other thing I want to measure with this setup is the coverage of the hron/driver. When you walk around the room as you stay in the pattern the sound sounds very even. When you get near the limits of the horns coverage you can here where its pattern control breaks down. Vocals sound pretty close to the same but the high end drops off. This happens just outside the width of my front row of seats so the coverage pattern is well matched there. With the larger K402 the dropoff should go lower in frequency then the K510.

I also spent some time working on my external sound card. After installing about 80megs of Sound Blaster updates (just for the soundcard... insane... I remember the days when the sound card driver was around 14k...) it looks like I was able to record with it again. Something is still screwy in that setup though as anything played out to the line out (tone/noise generators and such) is automatically coming back in the Line In even with no cables plugged in so it is looping it in software somewhere. I need to get that shut off to be able to make measurements with the software.

Shawn

[bodcaw boy]

sooooo shawn,

where you at on this?

roy delgado

[sfogg]

Hi Roy,

I hooked up the other 44xt and put the K510/44xt on the L/R channels and put the center back as it was. I haven't had as much time to listen as I would like but I was able to get a few good hours in anyway listening in stereo. Sounds good, the combo images well, the phasing/mixing tricks on 'The Division Bell' come in very clearly for example. Tonally the speakers sound very even from all of my seats which is great.

I have the K510s toed in as it was needed to get coverage to the whole front row. I want to play with that a bit more to get the toe in such that the horns cutoff is aimed right down each side wall. I was able to do that with the multicells by filling the outer cells on the L/Rs and that was pretty effective.

Still want that third unit to hear the setup in the way I normally listen to music.

Thanks,

Shawn

[Erik Mandaville]

Shawn:

Do you listen to music in full surround? How do these new horns image in the stereo setup you're using until the third driver arrives?

Erik

[sfogg]

Erik,

Yes, normally in full surround. Since I don't have the third driver yet for the K510 I have just been listening in stereo. I haven't tried surround with a phantom center yet. From what I have heard so far they image very well.

Shawn

[sfogg]

After too much delay I finally got the third speaker up and running. It took the place I ordered from about a week (and three phone calls) before they would ship me a replacement driver for the one that never made it out of their warehouse. Just to make things more complex right after shipping that third driver the missing driver turned up in their warehouse so they then turned around and credited me for it. I had paid by Paypal so they refunded the cost of the driver which they shouldn't have done as they had shipped that replacement driver. After another 45 minute phone call trying to explain to them I owed *them* money I finally got that (hopefully) squared away. Couldn't pay by paypal so they are invoicing me for that last driver.

So anyway.... the third driver arrived. Took a couple of days before I had any time to install it. I finally was able this weekend. I pulled out the 805b/288 and disconnected the 2404 from the center channel. Bolted the K510 to the 44xt and wired it all up and reprogrammed the center channels Behringer for the two way setup.

Finally... after weeks of delay I was going to be able to hear the system with K510/44xt across the front three speakers......

..... or was I?

Turned on the system and it immediately sounded very very wrong. I was getting no output at all from the center channel K510/44xt. Double checked my wiring, double checked the Behringer. Everything looked OK.... still no sound. I swapped the left K510/44xt to the center just to verify that it should play and it was working fine there. So I then preceeded to check the latest 44xt with a multi-meter...... open circuit.... that would explain things.

At this point I just had to laugh.

So I opened up the bad 44xt (my what a big diaphragm you have.....) and neither lead was connected to the diaphragm. They are just push on terminals and they either both came off in shipping or where never connected from the factory. After reconnecting them and closing up the driver again everything was working.

When the L/Rs were two way with the K510/44xt and the center was three way with 805b/288/2404 the center was a poor match to the L/Rs. It was screwing up the clarity of the L/Rs so I was mostly just running without the center while I was waiting for that last 44xt.

I have only spent a few hours listening but it is good to get back to three speakers up front again. The great vocal clarity I had while just listening in mono to the single K510/44xt is back and now the front stage all matches again. The front three speakers do a great job of imaging and sound very consistant in all my seats. I had originally moved to the 805B from the 511B to get better coverage over my seating area. The 511B (2 way with 902s) sounded good in the sweet spot but in the seats not directly on axis they were progressivly more rolled off. The K510/44xt has what sounds like even better coverage then I was getting from the 805B and it is doing that two way.

On the extreme top end the difference between the K510/44xt and the 2404Hs is interesting. The 2404H had a touch more sparkle but they also sounded a little more noticeable as being 'hifi'. The K510/44xt sounds a little more natural in that regard. It is sort of hard to explain.... things like tape hiss sort of had a somewhat more obvious all around you sound with the 2404H while with the K510/44xt it is more subdued and more 'on stage'. That is probably due to a combination of dispersion (the K510 has far less dispersion then the 2404H, though my room is very dead so that in theory would reduce that difference), FR and maybe just level balancing of the 2404H in the system.

I have not been able to listen/watch any movies on the system with the matching L/C/Rs. I sold my projector this weekend and it will be a few weeks at least before the new unit comes in. From what I have heard with music though I expect the L/C/Rs will do very well on movies.

Shawn

[DrWho]

So would you say an improvement or just different?

[Deang]

I thought those were the same thing:)

[sfogg]

Something can't be an improvement if it is not different....

Shawn

[mark1101]

Leave everything the same and change the listener. The sound could get better or worse.

[PrestonTom]

Shawn,

I am interested in your comparisons of the Altec 511/902 to the K510/PeavyXT44. If this is more appropriate for a another thread we can do that also.

There may be a bit of apples and oranges here, but tell me if I have got it right. The application would be a two way with something like a Jubilee bass bin with a crossover (steepish with time alighnment) at 650 -850 or so depending on the stability of the phase, frequency response and dispersion

From what I gather are these the highlights?

Altec 511/902:

Beamy at the high end. Larger horn so may have better controlled dispersion at the low end. I assume it is less able to handle power at the low end given the smaller driver (diaphragm). May need some EQ boost at the higher frequencies, perhaps 3-6dB per octave above 4-6 kHz or so. Not sure about the dispersion at the lower end. Not sure about how clean the sound is (distortion of the driver and with this loading). Not sure about the efficiency of this combination. I assume the best strategy is to get a used horn for about 100 per side and a new driver (clone) from Great Plains with the appropriate diaphragm (I assume aluminum, light) for the extended highs for about $250 per side although I am not absolutely sure about the price and I am not sure about the longevity of these diaphragms.

K510/ PeavyXT44:

Less beamy since it is somewhat of a CD horn. Advantages of the Tractrix geometry (less planar wavefront at exit and I assume a different pattern of diffraction at the exit). I assume this also effects the dispersion control at the lower freqs (although the horn seems so small to give much control, but I am ignorant). I assume less beamy at higher frequencies, but will also require EQ (perhaps a greater degree of EQing since it is CD). Not sure about the dispersion at the crossover range. Not sure about how clean the sound is from this driver, although the larger diapragm should better handle the lows especially at higher power levels. Not sure about the efficiency of this combination The price of the driver is about $300 per side I believe, and I assume arangements would need to be made for purchasing the horn.

Do I have it right? Are there other big considerations that I have forgotten? Obviously there are a number of variables, I am most worried about the major ones.

I really have asked quite a few questions (I beg your indulgence). But you are in a unique position in that you have heard and measured two of the prime candidates (you also appreciate the utility of a spectrum analyzer). There are a number of price/performance trade-offs in the final choice. I hope these questions will be useful for other forum members as well.

Thanks,

-Tom

[sfogg]

Tom,

"I am interested in your comparisons of the Altec 511/902 to the K510/PeavyXT44. If this is more appropriate for a another thread we can do that also."

OK, I'll give it a shot but this is going from memory as I haven't compared the 511/902 directly side by side to the K510/44XT.

"From what I gather are these the highlights? "

Yes, it looks like you have that pretty close. A few additional comments on the combos...

For the 511/902....

Yes, it tends to beam more and more up top. In the sweet spot it sounds fine ( likely depends upon the room for what the reflections do to the sound) but off axis it gets softer. This wasn't a problem in my old setup (further away from the speaker...less coverage angle needed) but in the theater it became a larger problem as I basically needed wider coverage for all the seats that were closer to the speakers.

Probably needs less EQ then you suggested. I just boosted the top end 2 or 3 dB using the treble control in the Lexicon and that sounded pretty close. And I didn't always run the boost either the combo could be used without EQ. The collapsing dispersion of the 511 is basically a form of EQ boost up top.

You can problably get a pair of 511B for $150. New drivers from Great Plains are $200 each I believe. The 902s are rated for something like 15w with 500hz crossovers. Having said that I ran them first order at 400hz with an ALK Type A for awhile and had no problems. They are tougher then the specs might have you believe. The 902/511B goes a little lower then the K510/44xt. Efficiency is slightly higher then a K55... probably around 105/106dB/w/m. Replacement diaphragms are around $90.

For the K510/ PeavyXT44:

Much less beamy. The sound is very even over its coverage area. Will require EQ. I think the settings I ended up using resulted in around 12dB of boost at the very top end. The driver is rated for around 111dB/w/m. Very smooth both audibly and measurably, the 511b/902 I don't think is as smooth. The driver is rated for 80w or 100w of power continuous with a 500hz crossover with peaks of 200 or so watts. Ferrofluid in the gap which might help damp the diaphragm. I would think on a suitable horn it should have no power related problems going lower in a home setup. Factory replacement diaphragms are around $100. There are also aftermarket units including a JBL 'ribbed' variety. I suspect the diaphragm sizing in the Peavey is a clone of the 4" JBLs, which potentially could mean some of the aftermarket JBL BE diaphragms might fit the Peavey.

"But you are in a unique position in that you have heard and measured two of the prime candidates (you also appreciate the utility of a spectrum analyzer)."

Like I said I haven't run them side by side but I think the above is pretty close. If you really end up narrowing down your choices to those two and feel like making a road trip we can try and set something up sometime. I only have one 511B now though so the comparison would have to be in mono... with the added advantage of being able to switch between the two setups live with the click of a mouse.

Shawn

[Erik Mandaville]

Shawn:

"I only have one 511B now though so the comparison would have to be in mono... "

I know of another one! If you and Tom decide to get together, I'll ship it. Just let me know.

Erik