A port for the Heresy

[lorcoll]

I would increase the output of the K-22E and I need to know what can be the dimensions of a port (like the Cornwall)in the Heresy's cabinet.

Can anyone help me?

Lorenzo.

[krustyoldsarge]

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On 5/1/2005 3:16:31 AM lorcoll wrote:

I would increase the output of the K-22E and I need to know what can be the dimensions of a port (like the Cornwall)in the Heresy's cabinet.

Can anyone help me?

Lorenzo.

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Check out this thread:

http://forums.klipsch.com/idealbb/view.asp?topicID=64777&sessionID={9CFDF914-BEE6-43C0-850C-FD4ADF3BFE5E}

[J.4knee]

I just bumped that thread back up in 2CH ...still awating Waynes A/B results.

[DrWho]

To properly port the heresy, you need to also increase the cabinet size to a total of 3.5 cubic feet. Two 4" ports with a length of 12" then extends your -3dB point down to 40Hz (111dB max acoustic output at 40Hz). When doing this, you may want to implement a high pass filter to cut out frequencies below 30Hz in order to control the cone excursion (which will exceed the capabilities of the driver if you push it too hard).

There really is no big advantage to simply porting the current cabinet. The -3dB point moves to 55Hz and you get a slight bump in the response above 80Hz. You will still have the same excursion problems (just to a lesser degree).

I'm working on building a totally reversable heresy port mod right now that uses a slot port underneathe the speaker (dimensions of the port are: 14 x 2 x 13.2 inches). The whole port and rear chamber will screw on the same way the current rear panel screws on. With a little modification, you could probably even use the current rear panel as the rear panel of the extended rear chamber/port. I will be adding T-Nuts so that the screw joints can be stronger (and so that the screw holes won't wear down changing back and forth between sealed and ported).

Here's a rough to scale sketch:

Sometimes these pics can be hard to understand, but just picture building a big chair for the original heresy to sit on. I'm thinking some sort of gasket should be implemented to help seal the two sections.

[bhendrix]

Interesting concept, Dr. Who. What would be the ideal dimensions of the cabinet if one were to build a new cabinet from scratch using the Heresy components? It seems a taller cabinet would help get the mid and tweet closer to ear level as well. An increase to 3.5 cu ft would not-quite double the height if you retained width and depth. That would put the tweeter about 35" off the floor.

[Daddy Dee]

Dr.Who.

Hope you get that project finished soon so you can post on the results. Looks most interesting.

What method did you use to determine the port and cab dimensions?

[DrWho]

djk gave me the T/S parameters for the K-22E and I plugged them into WinISD and modeled everything there. He also ran through the calculations himself and recommended adding 1.5 cubic feet to the volume (for a total of 3.4 which is basically 3.5). He also recommended a corresponding port length, but I forget what he said. Basically, the ports need to be tuned around 35-40Hz (the difference between the tuning isn't that huge...building irregularities will have a larger effect...at least with me building it, lol). Different port lengths and diameters can be used for the same tuning, so it's just a matter of finding a combination that fits the best in the cabinet that keeps the air velocity low enough to not be audible.

I'll see if I can't dig up that thread, he also posted the T/S parameters for the new woofer in the heresy II and recommended a drop-in replacement from a driver available at partsexpress (which allows for larger XMax which means lower highpass cutoff). I believe Formica also has this information as well.

Right now I only have a single center channel heresy to experiment on. In fact, I bought it to A/B the difference between the ported heresy and my chorus II mains (they spec out to be about the same). If it sounds better, then I'll find myself purchasing another pair of heresies and using 3 of them ported across the front. Dunno what I'll do with the chorus II's yet.

[Marvel]

Al K. posted info quite some time ago, for his "Heresy on Steroids."

20.75" deep x 16.5" wide

Bass box was about 27" high.

Mid and tweeter moved to box on top, with a different Mid and Tweeter.

It was ported.

Marvel

[jwc]

You know Al got that thing down to 30 HZ with the K-24 driver. However, the Cabinet was 4.3 cubic foot not including the HF section. Heck, the Cornwall is just over 6 cubic foot. If I were to have a cabinet that big, I would just stick to the cornwall.

However, 30 HZ sounds nice.

[Daddy Dee]

DrWho.

Thanks. Can't wait til you get it built.

[Olorin]

Dr. Who, you should just just buy a pair of Tangent 400s and be done with it.

OTOH, if you want Heresys, I have four of them available now.

[DrWho]

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On 5/2/2005 11:11:24 AM Olorin wrote:

Dr. Who, you should just just buy a pair of Tangent 400s and be done with it.

OTOH, if you want Heresys, I have four of them available now.

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I just looked it up on the site:

http://www.klipsch.com/product/product.aspx?cid=156&s=specs

How come there isn't that much talk about the Tangent series around here? Were they only around for a short time? I can't believe that it's totally a ported heresy (same drivers and everything). Has anyone ever had the chance to compare the Tangent 400 to the Cornwall, chorus, or forte?

The only advantage I can see left to doing the mod is that it's reversable and it has a different footprint, which in my situation is a big plus.

[Olorin]

It uses the same driver complement and crossover points as the Heresy II, so it seems to me that it should fall right between the Heresy II and the Cornwall II. Unfortunately I have not had the opportunity to hear one, so I'm speculating right along with you. That said, I would definitely expect it to sound more like a Cornwall, especially a II, than like a Chorus or a Forte.

Incidentally the Tangent 500 also uses the same driver set, but it uses the Quartet's passive radiator in place of a regular tubed port. The passive is on the front, yielding a very tall speaker. Of course, the 400 is not especially small either.

[eq_shadimar]

If you want to port your Heresy here is an example of how Klipsch did it from the factory:

Another view mounted and painted:

This is a HIP-II (Heresy II - Industrial and Ported Version) model that I use for my center channel in my Home Theater. I emailed the guys at Klipsch when I first got the speaker and they told me that it was made for nice clear voice projection and rolls off at about 60Hz. It makes an awesome center channel for HT since the true bass can be handled elsewhere. All the dialogue is crystal clear. Here is a link to my web page with the full specs

http://www.madtomstudios.com/HomeTheater/klipsch_heresy_hip_ii.htm

I would not use this speaker as a main or in a 2 channel only setup.

I hope this helps you out.

*** EDIT ***

The guys at Klipsch were not 100% sure about the drivers and I have neve removed them to find out what they really are.

Laters,

Jeff

[lorcoll]

Hi Jeff,

could you measure the diameter and the length of one port? (It would be easy take that from the front of the motorboard).

Thanks.

Lorenzo.

[DrWho]

The HIP-II uses a different woofer than the consumer versions so the same port tuning isn't going to work. The pro versions is probably tuned closer to 60Hz because they're more after power handling and SPL rather than lower extension. Heck, looking at the specs the sealed consumer heresy II is 63Hz-20kHz ± 3dB and the pro ported version is 60Hz - 20kHz ± 4dB.

If you really wanted to port the existing Heresy cabinet then you need to go with a different tuning from the pro heresy. Two 2.5" diameter ports with a 10" length tunes the existing cabinet to 35Hz. I find it interesting that when going this route, the ported K-22E (H-I woofer) performs the same as the sealed K-24K (H-II woofer). So this is basically a pointless mod because you can get the same performace from a sealed cabinet with the better woofer.

[Olorin]

IOW, drop in K-24s and you're done?

[DrWho]

ya basically, but this is when you keep the original heresy cabinet size.

In the bigger cabinet, the K-22 will still outperform the K-24. But then again, the K-24 in a bigger cabinet will outperform the K-22. The K-24 basically will always go 5-10Hz lower.

[eq_shadimar]

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On 5/4/2005 12:19:54 PM lorcoll wrote:

Hi Jeff,

could you measure the diameter and the length of one port? (It would be easy take that from the front of the motorboard).

Thanks.

Lorenzo.

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Sure I will try and do that for you in the next couple of days.

Laters,

Jeff