DavidF

Interesting. Trying to think this through. What would be the design goal? A port is typically used to extend bass response. I got that. But compared to a seal box the woofer output is substantially reduced at a given resonance and replaced by the vent output. In this case though the woofer is horn loaded. Would the vent also be horn loaded to maintain overall sensitivity from both outputs? In other words, aren’t you going to lose some already-limited horn bass response and replace it with the vent response at a substantially lower output level?

H-D and Buell may be a good analogy to brand identification which is, in part, the answer to your question. Paul Klipsch had several engineering principles that he adhered to throughout his involvement with his company. High efficiency provides low distortion and a dynamic sound where both combined form the prime characteristic of the brand over many years. Additionally his speakers were voiced with a flat-to-rising frequency response that was quite the opposite of many of the low efficiency models that allowed a dip in the mid range or falling high-end response to mimic the large symphony hall effect of sound propagation. So, put together all of the design traits Klipsch used and you have a house sound. I suppose that to many the Klipsch house sound seems “bright”. The house sound did not mimic the Altec theater sound (rolled off bass and high end). Nor did it mimic the symphony hall tendency to roll off the highs and add bloom to the mid-to-upper bass. To my ears the overall Klipsch sound provided a quality of reproduction that does remind me of original sound. Original sound has a certain bite and air. I read of people who just don’t like the horn sound, though. So there could many reasons Klipsch don’t appeal to all. H-D certainly has a design and riding experience that all who ride them know and love. Think of H-D and you think of a big twin set into a long low frame. The Buells hardly fit this H-D house design, however. Just as Paul would not continence a low-sensitivity design with an “audiophile” sound I sense also that Willie G. could never bring an upright frame that actually corners into a H-D catalog.

And a box built in this shed... I also agree with Dean. All kidding aside isn't Klipsch one of the few present manufacturers that makes all of their own drivers? Klipsch made some of the drivers and woofers in house but this was not, is not, the same across the entire model line. B&W, Dynaudio, Focal, KEF, TAD just off the top of my head make their own drivers. I am sure there are several out there.

I would offer some caution about using expensive components in a Heresy II. Some in the forum will argue otherwise and might offer advice more in line with your expectations. What works for you is always the key. The drivers of the Heresy are good quality but hardly in the higher end of the engineering/price spectrum. In any event they sum together to work beyond what could be expected of them. Personally I would hesitate at spending more for the crossover than all of the drivers put together. More of a cost/benefit consideration rather than a penny-pincher’s lament. I have the Heresy II and have used a few different component combinations. The only noticeable difference was using a better quality cap in the mid leg of the xover. The effect was to allow for more detail in the mix. Not so much that I could guarantee hearing the difference on any recording, or necessarily at any time. What I am trying to say is that any improvement for me was fleeting. I went with Clarity Caps all round since the component values are small for all legs. I can’t comment on different coils. I use a larger gauge wire with laminate core. I did not notice any difference but I don’t push the Heresy’s that hard. The sound loses coherence and dynamics when the sound levels get high.

Not sure what you expect but that is a really large enclosure for sealed box application. The bass response will droop considerably.

The xover is usually the last significant part of the design process as the designer “voices” the system. An experienced designer knows how to lay out a crossover design pretty much based upon a sense of what will work. Then some empirical testing and measuring is needed to further refine the filter. This is because using actual drivers with their variance in impedance and response at any given test point will not fit the theoretically perfect design based upon a fixed impedance and frequency response. Finally the designer will fine tune the filter components using either a desired measurement criteria or simply by listening. You can see that if even a small tweak in the filter or a driver substitution can upset the finely tuned design. So if you are considering changes, and major changes at that, will it change the timber of the system response? Absolutely. Most times in a negative way. My comments are not to discourage your system tweaking but more to caution against thinking that simply by swapping speaker system components you could expect such change to be an “upgrade”.

Take the system down to basic two channel. Especially go around the room correction equalization. No subs, etc. See if the sound clears up. I would think that the amp section is breaking up for lack of power/current reserves.

Recycled motion picture show seats for the gallery. Very cool...

The horn tweeter is starting to beam above about 8,000 Hz or so. Meaning that the off axis response is falling off faster than directly on axis. This is going on with the mid horn as well. The amount of high frequency energy bouncing off the walls, etc. is therefore less and this makes the overall power response droop depending on your exact listening position. The fix sometimes used is a form of equalization in the passive xover to allow the tweeter response to rise a bit at frequencies above 8-12,000 Hz. Though this helps in the overall power response it can sound harsh and piercing on axis with the drivers. The EV unit used by Klipsch actually performed better in the horizontal plane when the long axis of the horn was up and down. Could be that the horizontal orientation used by Klipsch better blended with the mid horn response so that is why they chose to keep both horns horizontal.

I know the feeling, well. Klipsch won't have a direct replacement. The model they suggest is different. To what extent I can't confirm but you really would need two to ensure matched response from both stereo pairs. Otherwise, you may need to shop on ebay etc for a used replacement for your particular driver from the H 1 series.

Sorry, yes, connect the amp output directly to the woofer. This will take the xover out of the circuit. This may not the answer but just to be sure the xover is not the culprit, here. Always careful not to cross those speaker wires, as you have already determined.

Excessive heat will deform the former, causing an out of condition. Still enough clearance to move with signal changes but some of the coil will rub and catch on metal outside the gap. More power still can cause the coil wire to just blow like a light bulb filament. Shorting the input terminals could cause a burst of DC current to pass through, or drop to very low resistance, but like mentioned above the first thing that may blow is the amp, or the amp fuses. I would also try bypassing the xover and connect the woofer directly to the amp output just to eliminate a bad xover circuit.

A notch filter is really tough to work with without some means to test results. As always you are dealing with changing values in impedance in the circuit.

Double post edit.

Raspy in the treble sounds more like the mid range driver. Some folks just don't like horn/compression driver sound and find ways to express their bias in what they hear. I have heard that for years about "horn sound" and take it as that- a bias. I have not read the article so I better wait before I say more about the review.

The speakers will resonate the same whether on the floor or up on stands. Having a speaker firmly set to the floor often affords the means to shift some of the resonance away from the cabinet to the floor (assuming a wooden floor). That can remove some of mud out of the lower mids. Perhaps that will clear up the bass response by not actually altering the bass response but rather by removing some grunge in a range above the bass. Whether audible or not is going to be arguable. Setting the Cornwall up on wobbly stands can work two ways against you. First it may not act as a resonance sink like a firm fitting on the floor. Second small gaps between the floor and stands, and then between the stands and cabinets, may cause a secondary source of sound from the actual vibrating contact points. So, my first concern is a stable platform. As mentioned by Moray a three point stand is a good way to get even pressure points at the floor and cabinet. You need to factor in stability control, however. Building a stand with mass such as a sand-filled idea will have mixed results. Unless you have the means to actually measure progress. I would concentrate on a stand that is made of sturdy materials with good joinery technique to avoid creating a “new” source of sound.

Clearing out a double post.

This series of the DUAL line used a specially made Ortofon cartridge that was incorporated into the head shell. DUAL named this ULM (ultra low mass) as it was designed to be very lightweight. Just going by memory there was two or three series of the ULM with three levels of cartridge/stylus build quality. Your model had the ULM 60 and replacement stylus DN160E. Original replacement stylus from DUAL are long out of stock much less production. If you are offered a “new” stylus then it will be an aftermarket item and subject to unknown quality and specs. The 714Q (which I use) and the 731Q had a special kit that replaced the head shell to allow mounting a standard ½ inch cartridge. A counter weight plug was part of the kit to add more weight to balance the heavier cartridges. The original cartridge assembly is very lightweight and compliments the low mass arm quite nicely. It may worth trying to track down a good quality aftermarket stylus. I like the sound though I am still using an oem stylus. More on the subject: http://www.audiokarma.org/forums/showthread.php?t=335608&highlight=714Q

Sure won't fit on the back of the terminal cup, will it?

Nice to share this reflection back in time with you. Sounds like one of those bonding moments between sons and fathers that you don't recognize until many years later. With me it was HO train sets with which my Dad helped me. Or, more precise, he allowed me to help him. Images and memories I still carry to this day.

Does the pitch variance light work? Does it show any change in rotation speed? I have not owned the top-of-line BIC but a couple of things come to mind. The belt has likely sat in one position for many years. The rubber tends to dry out and deform so that as it rotates the elasticity varies. Second is the main table bearing that may be gummed up or dry. Not sure how to access but it should be fairly straight forward. Here is a copy of a service manual. You will need to register at the site to get access. http://www.vinylengine.com/library/bic/980.shtml Edit: well there goes JHOAK just a step ahead of me!

I always caution tweakers to take a cautionary approach to active xovers. In better quality speakers the original passive design is engineered for the specific speaker system. The designer knows that “perfect world” theoretical applications of filter design go out the window using actual drivers in actual enclosures. The theoretical design may be a starting point but rarely survives in the final design. Inserting an active filter into the system takes you back to the “perfect world” point though some features allow you some added flexibility such as adjustable slopes and gain controls to match driver sensitivity. If the drivers you use are relatively flat around the xover point you may have good success with off-the-shelf filters. This is often the case crossing a woofer to a mid where each are well behaved an octave or so around the xover point. You may not be so lucky in the case of the RF-7. The passive design likely compensates for the diffraction loss with woofers on a narrow baffle as Ski Bum mentions. The high filter likely has some equalization built in to compensate for the horn response fall off at higher frequencies. I could go on with other examples but you get the point. A xover point is where the frequency response is transitioning. A high pass filter set at 1200Hz means frequencies above 1200 are allowed to pass but roll off below that frequency at a graduated rate. A typical design will have the response already down 3-6 dB in magnitude at the 1200 Hz xover transition point and continue to attenuate going down in frequency so many decibels per octave depending upon the filter configuration. A low pass is the inverse. Tweaking can be fun and I say try it but be honest with yourself in whether this change results in an improvement. [edited for clarity]

I would not be too quick to conclude there is something wrong with the Chorus. It may be simply differences in presentation between the two. From repsonse graphs I have seen the La Scala has some peaks in the high end response, particularly around 5-7K. This will tend to add some "sting" to sibilance and mid harmonics that are more subdued in the Chorus. Try listening a while to the La Scala to allow your hearing to adjust. Then go back and listen to the Chorus for a while.

The us of a car battery for bias purposes may be, hopefully, out of context. The battery applies very little if any current. Why, then, a car battery? Unless this was a power source for a DC pre amp or something else in the chain. Still, what would need the amp potential of a car battery? The link over to the Lansing Heritage forum provides some background on the application of bias in some JBL designs. See post #6. http://www.audioheritage.org/vbulletin/showthread.php?3555-Bypassed-and-Biased-Capacitors

No material in ealier Heresy models. It is a relatively small enclosure to be able to support standing waves but still known to be "lively". The second generation included a sheet of foam bent in semi circle around the woofer. Not sure about the 3rd generation.