ported heresy mod...

[DrWho]

Dr. Who, did you ever port that heresy?

Yes.

[Rockets]

Mike Colter... my crossovers look a lot like these posted by BC http://forums.klipsch.com/forums/t/76053.aspx?PageIndex=1 with the round cup. They may be E2's, but I'm not sure. I was trying to avoid tearing them apart to measure them, before I had a schematic, but may reverse engineer anyway.

Marvel... I could kill you! [] I really was trying to avoid getting deep into another project. All I wanted to do was change a driver, drill a hole and be done with it. Then you had to throw that teaser out there...Now you've got me dreaming....adding a 1 cu. ft basement might not be that time consuming. (this is how I get myself into trouble time and time again) What size ports do you think those are on the Tangent 400, about 2" ??

Would using the 200w K-42 kill the bottom end by much??? I don't need that much power, but now I'm thinking about thise guy I work with that's in a band, who's looking for some midsize, full range portable speakers.

Thanks!

TC

[Marvel]

Marvel... I could kill you! I really was trying to avoid getting deep into another project. All I wanted to do was change a driver, drill a hole and be done with it. Then you had to throw that teaser out there...Now you've got me dreaming....adding a 1 cu. ft basement might not be that time consuming. (this is how I get myself into trouble time and time again) What size ports do you think those are on the Tangent 400, about 2" ??

That's what I'm here for...glad to oblige. [:|] A co-worker picked up a pair of Tangent 400s in Atlanta last year. He lives five minutes from work, next door to my son (who also works with me). I keep meaning to get measurements...

I don't know about the K-42... Maybe Dennis could chime in.

I'll do it next week if you want... all I need is the excuse...

Bruce

ps Fs on a JBL123A is 25Hz, but the xmax is also on .31" which is greater than the K22. Also has a pleated surround which is a plus in my book.

[Rockets]

Marvel, no real rush. I am curious though, but I also need time to think about it anyway.

Do I add a cubic ft to the existing cabinet, port and stick with the K-22 for a bottom end of 38hz and 100w capability? Or do I port the cabinet as is, and add either a JBL 123a @ 50 watts or JBL 2213H @75 watts for a possible low of 25 hz?

Decisions, decisions...

Actually I've use the JBL123a before on my back porch speakers. I knew they had some bass, but never knew how low. These were and absolute nightmare for me to install. I know they look simple, but I SUCK at wood working. The other problems were i ASSumed my walls were square and I pre-cut my pieces. Then, a couple of compound angles popped up that I had to deal with. I ended up putting in a zillion stainless screws to draw everthing together...and I never finished painting their sorry little heads!

[Marvel]

Compound angles... that' swhat makes the Khorn harder to make.

Well, the Fs on the 123A is 25 Hz, but my JBL 4311s are only rated to 45Hz, and that is a ported cabinet close to the size of the Heresy. The Heresy II in the bigger box would be more of a proven product, and handle more power.

I was intending to take the parts out of my HIIs and build new cabinets that have the dimensions of the Tangent. Seems like another project on the horizon, doesn't it? I'm trying to dig up the money for the wood to build some MWM boxes, but it will take a lot. And the price for 4x8 birch has about doubled over the summer.

Bruce

[Rockets]

Marvel, I pulled this off the Altec site.

An original L100 (with the LE20 tweeter), has a 2" diameter vent in the front baffle, with no tube (1" vent length, due to the 1" thick baffle). This gave a tuning frequency of right at 41 Hz.

The L100A (with the LE25 tweeter, and the "elbowed" vent tube) had a vent frequency of right at 31 Hz.

The dimensions of these HP-1's are about 667 cu In bigger than the L100a. So I guess if I were to go that route w/ a JBL 123a3 I'd need a 9" cubed brick...or something close! in any case 31 hz ain't too shabby.

[Marvel]

I never tested/measured the 4311s to see the tuning. JBL just spec'd it 45-15k plus or minus 3db. Mine have the elbowed port. I have some JBL 2025H drivers (12 inch), that I had thought of using for a project, but they are for sale. Their Fs is only 48Hz, but they are rated at 400 wattts.

Since I have a pretty nice pair of HIIs, I know how they sound, and new cabinets for them would be pretty easy.

Bruce

[Rockets]

I hear ya. If my woofers were not toast, I'd follow your path. However, since I need to replace them...I may diverge over to the dark side and marry part of theirs with Klipsch. It's just less work for me!

THANKS for all of your input!

TC

[dtel]

Dr. Who, did you ever port that heresy?

Yes.

Way to drag it out Doc. []

[Marvel]

Way to drag it out Doc.

He's just averaging it out... [:#]

[Rockets]

I can recall no previous issues w/ the Doc, so I don't know what to think,

Way to go Dtel...just keep stirring that pot...I was going to let it go, and then you had to go go there[](just kidding) TC

.

[DrWho]

Way to drag it out Doc.

He's just averaging it out...

lol, oops! I meant to post a link... [:$]
http://forums.klipsch.com/forums/p/56006/541948.aspx#541948

Man, I've learned a lot since I did that a bajillion years ago...I still do all my CAD in MS Word though.

[Rockets]

Thanks for the link Doc, it was interesting.

I have a confession to make though. I'm a Heretic... not only am I a heritic, but I'm also a hack. I replaced the blown K-24's with JBL 2213h's...the pro version of the JBL 123a3, but rated at 75 watts continious. http://www.jblproservice.com/pdf/Thiele%20Small%20Parameters/Theile%20Parameters.pdf I ported the boxes, rebuilt the crossovers, stiffiened the walls, added some fluff inside the box and dampened the carry handles...would have done the horns, but I ran out of material. I wish I had some measuring equipment so I could quantify what I'm hearing, but I don't. I'm going to do a search online to see if I can find a audio test track that I can play through them. If need be I'll hook up my tone generator, but still won't be able to plot the waveform.

If anyone has the spare time and software to predict the waveform using the JBL 2213h in a Heresey box, w/ a 3" X 10" port and the only real change to the crossover was letting the woofer roll off on its own...no 2nd order .. http://forums.klipsch.com/forums/p/39682/361064.aspx#361064 I'd APPRECIATE it. I should have asked before I dorked around with it...[:$] I have to tell you I am curious though.

As Mike noted in his thread the horns seem to slightly overdrive the woofers, I think I'd agree with him. Most people wouldn't notice, but a -3 db midrange cut would be nice.

Anyway, I have a new problem of sorts. When I crank the crap out of the speakers, the woofers really come to life and you can feel the thumps of the bass. The bad news is the ( K-53?...definitely not the k-55) midrange begins to sound like you're in a concert hall. I don't know if it's the horns resonating or if I'm pushing the diaphrams to their limits. Before I open these things back up and start doping them with rope caulk...any thoughts?? My amp is clean and w/o distortion, so I'm going to discount that as a cause.

One other comment, these can't hold a candle to my LaScalas, no surprise there, but even when I did an A/B and had the Lascala channel cut down -10db, they were still noticeably louder and had more bass. (there's a shock) I wish I had another pair of Heresies to compare with, or at least another K-24.

Once I solve the Hall effect, I'm going to call this project done! Over all I'm pretty happy with them. The overall sound quality is pretty damn good, just slightly out of balance to my ear...which may be a characteristic of the Hersey...not sure. I plan on using these on my deck, so it's not that big of a deal.

Any thoughts on the Hall effect, and the proper amount of polyester fluff to use woould be appreciated.

Anybody need any K-24 spiders? You can have them for FREE. Just pay the freight, and cost of materials for packing.

Thanks

TC

[Marvel]

I replaced the blown K-24's with JBL 2213h's...the pro version of the JBL 123a3, but rated at 75 watts continious.

Hmmm... my JBL literature gives the same T/S specs for the 123A and the 2213, but have PE at 50 watts. Since the Fs is only 25Hz, I can imagine they would do pretty well. My 4311s, to my own ears, compare well to my H IIs, although the HIIs have a lot higher sensitivity..

Bruce

[Rockets]

Marvel the 2213 is 50 watts from what I can tell, but the 2213H is 75 watts.

TC

[Marvel]

That would be an OOPS on my part. You are correct. I just looked at the sheets again. Every other parameter is the same...[:^)]

Bruce

[djk]

The 'H' has a Kapton former, the 'A' is paper.

You can use them with a 150W amp without a problem.

[DrWho]

I had the Hall effect with my ported Heresy too. I think the problem is that the port is actually too large, which introduces two problems: the port resonance moves into the passband of the woofer, and there is enough HF energy inside the box that bounces around and makes its way out the port.

Btw, when you say 3"x10", is that a 3" diameter port that is 10" long, or a 3" x 10" slot that has a certain depth to it?

As far as xover mods to the Heresy, I did a bunch of measurements a while ago and determined that bringing the squawker level down or even the tweeter was not necessary. However, there should be a lowpass for the squawker - and if there is one, it should be moved lower in frequency. I was measuring an extra 6dB or so at frequencies right before it crosses over to the tweeter. I never got around to fixing the problem (college budgets and all), but I might get around to fixing it someday. I've got a pretty detailed thread on that too - dunno where it is though. The problem is low passing the squawker will shift its phase around, which can screw up the transition to the tweeter (so the tweeter high pass might need tweaking too).

Regarding absorption in the rear chamber...keep in mind that it's essentially like adding ESR to the effective capacitance of the rear chamber volume...basically, it will change the Q of the cabinet influence (make it wider) which will widen, but lessen the LF reinforcement. Also, in order for absorption to be effective, it needs to be wider than 1/4 wavelength of the frequencies in question. 1/4 wavelength of 1kHz is about 3 inches as a point of reference - so 3" is kinda useless when crossing over to the woofer at 600Hz (where you'd need 5 to 6 inches).

[Rockets]

Thanks Mike for the reply.

As far as porting, I stole from others. For instance Gordon, over on the 'other' forum said this

"I currently have a pair of 123A-1 drivers in about this exact cabinet- 2.4 cubic feet (66 liters, plus or minus), tuned to about 30 Hz with a 4" diameter, 8" long port. They definitely do have prodigious output, and don't require a lot of power to do it! Not "hi-fi flat" exactly, but lots of bass slam. Just the ticket for DJ/small PA...
Regards,
Gordon."

If anything, I should probably not add any Poly, but add a brick as Gordon further states: Use the L100 box... 1.6 cubic feet (~44 liters), with a 3" (~75mm) diameter round port, about 9 inches (~180mm) total length. Tuning of about 30-31 Hz, f3 of about 43 Hz, nice "fat" midbass that will pound the #*&^% out of you at 80 Hz... If he's looking for power handling as an ultimate goal, the ported design with the 9" long port in the 44liter box will out-slam every other option using this driver, and will have good control over the driver with respect to excursion, down to port resonance. I'd use a 25 or 30 Hz rumble filter on it (just below port resonance)... with that, you'd be hard-pressed to damage it, unless you simply tried to slam over 200 watts into the cabinet continuously or something (ie, sheer over-power, burning it to the ground and whatnot)...

Frankly, I was afraid to cut a 4" hole in the cabinet. I was afraid that I'd have interference issues mounting the horn, which looking back may not have been the case, but when you're looking at a piece of 4" tube w/ an elbow, they're giant looking compared to the small Heresy box.

As far as the hall effect... I've read no where else of anyone having a similar issue, and when I thump the horn lens, it leaves a lot to be desired. Don't get me wrong, I think you may be on to something, but I'm not sure if downsizing the port is the answer. In my case, listening to Jim Morrison at a moderately high level, (Ok, My ears were later ringing) his vocals are such, that he sounds like he's singing in a hall. Since the midrange produces most of these frequencies, it led me to think the horn was resonating, or the diaphram was near it's limit. If the horn is resonating, then I can see where those frequencies would indeed bounce around inside the cabinet and out the port. (normally I don't crank the amp up this loud, but I plan to use these speakers outside on my deck, and the party mode may require it...before the cops show up) Why would the horn resonate when ported and not when sealed is the question.

Just for S&G's I'm going to dampen the horns and see if it makes any difference at all. I mean they should be the only source of the problem. I can't see the comprssion driver body/magnet resonating enough to cause it. If not then, I'll partially plug the ports...maybe use some of my wife's excess Turkey stuffing.... I'll let you know... Short of messing with the port, adding rope caulk to the horns, is there another solution to dampen the internal resonance? Ideally, you should treat the source first, but if that's not possible.... I've been told lining the cabinet w/dense foam like neoprene isn't the answer, so what is?

As far as the poly question, originally these HP-1's I have lived a hard, hard life. When I brought them home they REEEEEEEEKED of smoke from living in bars, and hanging out with tramps that only liked them because of the size of their horn. Inside they had a 1" by 12" by 18" foam pad that layed in the bottom of the cabinet, which also stunk. Knowing I was probably just shy of the 2.4 cu. ft internal measurements used above, I thought adding some poly would help improve things, but I didn't really know how much was too much. Reading your comment above, I gather the box ain't big enough for me to get all of the required stuffing...If I understand you correctly. If anything, using any at all, may hurt me given my trade off with the smaller diameter port, and I may need to reduce the internal cabinet size.

I'll probably leave the crossover alone. They killed my lab at work, so access to the necessary test equipment is gone. W/O being able to see the changes being made I'd be there forever playing an expensive guessing game...which I'm already playing now! The only difference now is I'm adapting the knowledge of others..and it's still biting me!.

Home Despot is closed today, so tomorrow will be the earliest for me to play. I'll let you know my results.

Thanks for the help,

TC

[Rockets]

150 watts is good to know. I don't have an amp that big, which is a good thing, otherwise the cops would visit me for sure. Once I have some of these other issues ironed out, I was thinking of loaning these out to a friend that plays in a band as he's been looking for some easy to transport speakers for smaller gigs. I'll need to verify w/ him what he has and if it's clean before these go out of my door.

Thanks