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effect of 2.5mh vs 3mh inductor on same load?


Alexander
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Looking at both the Forte I and T-5000's I see that they both share both the K-75 & K-53 drivers.  Also the Forte I k-23 and T-5000 k-28 share the same replacement driver. So this brings me to the point that the two speakers other than the difference in cabinet volume they are essentially the same. So here is the question, the two schematics are the same other than the Forte I a 40 ohm resister and 3mh inductor and the T-5000 has no resistor and a 2.5mh inductor. I understand the resistor but what  is the actual difference created with the two different inductor values?

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My thoughts are:

 

It is bad business for a manufacturer to offer a product to one retailer (say general retailer in the USA) at one price and then offer the same product to another (say military PX system) at a lower price.  The retailers argue for equal lower pricing.

 

My guess is that Klipsch made the Tangent series to sell to the PX system saying that they are a different product even though they are quite similar.  Small differences might be needed to support the argument. Hence we have Tangents in the PX. 

 

Regarding the resistor.  I think it is there to prevent problems if the driver burns out.  As one moderator pointed out, if the load is burned out, the crossover components form an LC series circuit to ground which could be a big problem.  But if you’re not going to failure mode of drive level, you don’t need it.  It has no appreciable affect on normal performance.

 

Why not use it in the Tangent? I don’t know except that wholesale price as established by the bean counters is sensitive to every little extra manufacturing cost.  Therefore an extra 50 cents in parts translates to $20 in retail price, IMHO.  Some buyers will use that in purchase decision making.

 

As far as the value of the inductor.  It should not make a difference and might have been changed to address small variations in the overall design and something which shows up in sophisticated acoustic measurements. I doubt the variation can be heard in any case.    

 

The bottom line is: Don't worry. 

 

WMcD

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  • Thanks WMcD for your reply, the reason for my question is that I will be building a new OEM/Crites  style x over for my t-5000's  but if I were to want to try and sell them at some point down the road there would be virtually no market. On the other hand if  I were to build Forte I x overs I would have a better chance of turning them. Hench the comparison of the two x overs as to how similar they are to each other.
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  • 1 month later...

Alexander, I am very interested in your efforts with the T-5000s.

 

I just lucked into a pair and they are no slouch.

 

In a side by side comparison with my Forte ii’s (un-modified) there is very little difference, with the exception, of course, of that magic tractrix midrange. The Forte ii’s take it a little lower at (very) high volume before distorting, but I think most of that is due to the T-5000’s less than stellar cabinet.

 

The pair I have definately needs crossover work.

 

I owned T-500s a while back and was expecting more (read punch),  the T-5000s have it! As I understand it, they have the same woofer as the Heresy iii. Half the impedance for 3db more in the chest?

 

I had Heresy ii’s and loved them, lack of low end notwithstanding.

 

I see these becoming full range Heresy iii’s that are at the right height.

 

Even just with a little bracing and refreshed crossovers these will shine.

 

Please keep us posted with your progress here and thanks for your post!

 

 

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Do some searching on the internet.  There are some filter modelers that will show you theoretical roll offs by each of the different components.

If you do some digging on crossover design, you can probably extrapolate what the difference would be, sound wise and on the impedance curve by substituting different values and looking at the results.

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Been busy of late but finally got back on task.  Finish building one xo off of the schematic, wanted to have it look real nice but too many goof ups and cruddy soldiering killed that. But none the less it will be functional. Did add a resistor at the tweeter and wired for bi-amp should the desire struck.  Will be building the second one and maybe we can have a better looking version.

T5000xopic1024.jpg

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On ‎10‎/‎28‎/‎2017 at 9:06 AM, geoff. said:

Alexander, I am very interested in your efforts with the T-5000s.

 

I just lucked into a pair and they are no slouch.

 

In a side by side comparison with my Forte ii’s (un-modified) there is very little difference, with the exception, of course, of that magic tractrix midrange. The Forte ii’s take it a little lower at (very) high volume before distorting, but I think most of that is due to the T-5000’s less than stellar cabinet.

 

The pair I have definately needs crossover work.

 

I owned T-500s a while back and was expecting more (read punch),  the T-5000s have it! As I understand it, they have the same woofer as the Heresy iii. Half the impedance for 3db more in the chest?

 

I had Heresy ii’s and loved them, lack of low end notwithstanding.

 

I see these becoming full range Heresy iii’s that are at the right height.

 

Even just with a little bracing and refreshed crossovers these will shine.

 

Please keep us posted with your progress here and thanks for your post!

 

DD77B82A-7885-4BA7-86F6-E0460F497852.jpeg

I agree, the T-5000's are a sleeper value wise - they have the same drivers as the Forte I but in a bigger box. May try building a set of Forte I xo's to see how they sound.  Curious if you have gone into your enclosures yet? Compared to the inside of my Forte II's they look to share all the same reinforcements & wood thickness.

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On ‎10‎/‎28‎/‎2017 at 9:55 AM, pzannucci said:

Do some searching on the internet.  There are some filter modelers that will show you theoretical roll offs by each of the different components.

If you do some digging on crossover design, you can probably extrapolate what the difference would be, sound wise and on the impedance curve by substituting different values and looking at the results.

Any one(s) that you might point me to that is better and/or easier than others?

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Had the T-500s, wanted the 5000s. Should not exclude the 400 or 4000's as major diff. the Passive

versus front ported.

Tangent line a good diy'er or experiment delight. Two diff T models purchased here were from ex-military.

Like the outboard or easy to replace design of XOs.

Happy listening...:emotion-21:

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Alexander, I finally did get inside my T—5000s yesterday. 

 

And if that is your first crack at a DIY crossover it looks damn fine to me! I have yet to knock one out, but I can’t see it looking any different than yours -looks just like the schematic, with lots of room to repiar or upgrade should the need arise. Nice.

 

I like the idea of outboard crossovers too!

 

One thing I have read HERE is that ferrous screws do have an effect on the coils if placed too close. Not sure what you used, but they look like stainless steel which would be fine.

 

The crossover was stamped as T-5000/T-4000. Drivers were k-75/ k-53, but the woofer was not labelled specifically(?). The woofer magnet was vented and heavy. 

 

As I suspected, I could see my maglite through the joints of the front baffle in several spots, and there was dust around the speaker terminal cup as it was loose. One screw was never installed on the woofer(!)- gasket was tight though. The passive was not very tightly fastened either. There are povisions for floor spikes in the bottom I had never noticed.

 

The rest of the speaker was (very) solidly glued and gasketed though! Slight corner bracing was used and the motorboard was thicker than I expected. Two pieces of acoustic foam were on either side vertically.

 

I took another posters advice and used contractors adhesive on the seams that needed it.

 

A great choice as it doesn’t run! I used a piece of cardboard as a putty knife to push it into the seems.

 

I will be adding extra gasketing material to all the drivers when I reassemble them.

 

I plan to cut a couple of small cross-braces before that. I will likely screw and glue them as looks are not paramount with THESE cabinets.

 

 

 

 

 

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Gasketing and gluing used.

 

I wasn’t sure if I would fit a caulking gun inside the cabinet so I bought the small tube of glue.

 

One small tube did one motorboard, not very cost effective. Lol.

 

I will buy the large tube for the next speaker, put a bunch on a board and just spackle it into the seems with a small putty knife. I should have thought of that the first time...

 

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  • 2 weeks later...

Geoff, I have the same xovers and the one missing screw as you have. Your woofer is a 4 ohm k28k, the replacement driver is also shared with the k23k & k25k of the Forte I/II family. I will put a light in the cabinets to look for "leaks" - hadn't thought of that :). In stock form they sound very good and as you mentioned they are very similar to the Forte II's - a great speaker for less than Forte's if you can find them and do not mind the size.  Looking forward to putting the upgraded xovers in and see how they sound, most of the original components were off spec by  well over 10%

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