[ooheadsoo]

Bob!  Should I do a straight inductor swap out, too, with my av series kit?  I don't remember the inductor value any more, though.

[brj]

Bob, thanks for the very educational post!

Any chance you'll be taking some of these upgraded speakers to RMAF this year?  The basic TP we heard in North Texas had a few issues, but I'm still very much interested in hearing some of your more upgraded offerings.

Thanks!

[Double Ugly]

The basic TP we heard in North Texas had a few issues, ...

That was unfortunate to say the least, Brian.  If it was bad enough for me to return my speakers, you know it was bad.   

That said, I wish you could hear them now.  The difference in 'then' vs. 'now' is huge in my room w/ my equipment, as it should be given the issues existing 'then.'  I don't know what Bob's plans are for shows and the like, but you're welcome to stop by my place any time you find yourself in the southeast.

I'll even take you out for the Mississippi version of Tex-Mex. 

Regards,

-Jim

[brj]

The difference in 'then' vs. 'now' is huge in my room w/ my equipment, as it should be given the issues existing 'then.'  I don't know what Bob's plans are for shows and the like, but you're welcome to stop by my place any time you find yourself in the southeast.

Thanks, Jim - I appreciate that!  I had a vague recollection that Bob planned to hit at least one show this year, and I thought it was RMAF.  Of course, an in home demo is likely to be better anyway, as even the best treated hotel room will pose challenges.

I'll even take you out for the Mississippi version of Tex-Mex. 

Ok, at the risk of completely derailing this thread... how does Tex-Mex "evolve" as it heads east?

[Carl V]

Bob!  Should I do a straight inductor swap out, too, with my av series kit?  I don't remember the inductor value any more, though.

Ditto

I have AV-2 Presence speakers.

I've always thought they sounded great at moderate levels & a bit constricted at loud levels.
I nonethelss like the SP AV-2s.

cheers

[Double Ugly]

Thanks, Jim - I appreciate that!  I had a vague recollection that Bob planned to hit at least one show this year, and I thought it was RMAF.  Of course, an in home demo is likely to be better anyway, as even the best treated hotel room will pose challenges.

You're welcome, Brian.  And in case I wasn't clear, the invite is real.

Speaking of rooms, the one thing I *can't* demonstrate well is their ability to image.  My room is a severe LIMFAC in that regard, but the quality of sound emanating from the speakers is unmistakable.

I'll even take you out for the Mississippi version of Tex-Mex. 

Ok, at the risk of completely derailing this thread... how does Tex-Mex "evolve" as it heads east?

Good Tex-Mex (as defined by Texas standards) is virtually impossible to find, but the wife and I found an acceptable alternative about 30 miles west of here.  It isn't the equal of what is readily available throughout most of Tejas, but it's worth the trip of you have a 'jones.' 

[brj]

Thanks, Jim - I appreciate that!  I had a vague recollection that Bob planned to hit at least one show this year, and I thought it was RMAF.  Of course, an in home demo is likely to be better anyway, as even the best treated hotel room will pose challenges.

You're welcome, Brian.  And in case I wasn't clear, the invite is real.

I believed you, Jim!   I had one potential trip to Jackson, MS last year, but it didn't pan out.  I'm not sure when else I might be heading that way, but if I ever do, I'll absolutely give you a call!

Speaking of rooms, the one thing I *can't* demonstrate well is their ability to image.  My room is a severe LIMFAC in that regard, but the quality of sound emanating from the speakers is unmistakable.

I understand completely.  My own listening room improved quite a bit when I put in some 8th Nerve Adapt rectangles along the wall/ceiling edges, but it still rang like a bell and was horribly asymmetrical - so much so that there was a frequency dependant shift in the imaging.  As a center located singer, for example, traversed the octaves, the image would very clearly float left and right depending on how the given frequency interacted with the room.  It drove me nuts!

I've reached the conclusion that proper room treatment may be as important as speaker selection.

Good Tex-Mex (as defined by Texas standards) is virtually impossible to find, but the wife and I found an acceptable alternative about 30 miles west of here.  It isn't the equal of what is readily available throughout most of Tejas, but it's worth the trip of you have a 'jones.' 

[BrunoB]

[The reason I mention it is that in silicon-steel EI cores, an air-gap between the center leg of the "E" section, where it would contact the "I," often will have engineered in an intentional gap.  The gap then prevents the two segments from actually touching one another physically.  If adjusted accurately, the gap will cause the inductor to go into saturation softly, just like in a ferrite.  That's what the Mundorf "Zero-Ohms Inductor" uses.

Just ask me, I'll tell you all about it.

-Bob

Bob,

If you don't mind, I have a technical question for you. I have a pair Mundorf "Zero-Ohms Inductor" in my speakers. Inductance is 5.6 mH. I decided to change the XO and needed to lower the inductance. What I did is to remove the I part of the Zero-Ohms Inductor and got 2.2  mH (E+I : 5.6 mH; E: 2.2 mH).  How do you think this would affect the saturation of the inductor? Do you see any potential sonic problem?


Thanks,

Bruno

[Aether Audio]

ooheadsoo,

Yes, we want to get rid of that inductor if...it happens to be a steel-laminate core device.  I don't remember so I'll have to go back and look at the schematic.  Specifically, if it's a "Sledgehammer" model (marketed by Madisound) - it needs to go.  I'll let you know the value ASAP.

Carl V,

Same as above.  Although, while the woofers of the AV Series are more sensitive than those of our MRS line, they have nowhere the excursion capability of those aluminum cone SEAS units.  That may be part of the problem as the AV stuff was never capable of the same SPLs.  But then, you don't need as much juice to drive them either.  Everything in engineering is a trade-off.  Nevertheless, I can guarantee those inductors aren't helping one bit.  PM or e-mail me and we'll get it all worked out.

Everyone,

FYI & FWIW...Regardless of what speakers you own - manufactured or DIY - and there's any way that you can find out what inductor is used in your woofer's Low Pass circuit - and it happens to be the above type - you might want to investigate replacing it.  I would suspect that there's 100's or even 1000's of those things out there.  While they "work just fine," you might be able to achieve significant improvements by replacing them.

-Bob

[Aether Audio]

Bruno,

What I did is to remove the I part of the Zero-Ohms Inductor and got 2.2  mH (E+I : 5.6 mH; E: 2.2 mH).

Ooops...uh...well, you lost most of what you paid for.  If you look at the links I posted above there's a section that describes the effect of the "air-gap."  By removing the "I" you made that gap REALLY big.  So big in fact that you basically turned the inductor into a standard non-gapped design.  Although in your case the remaining "E" core may be large enough to avoid saturation most of the time, the fact is that if you do approach saturation the inductor will saturate "hard" instead of gradually.

Considering that finding someone to buy them on the used market may have been pretty tough if not impossible, I guess you're not really out anything from a money standpoint.  Of course, if you could have sold them for a reasonable amount and then just bought Mundorf's standard coils, you might have been money ahead.  Other than that, the real issue is one of performance.  If you're not hearing any loss of resolution or degradation in imaging, etc. - I guess you dodged that bullet.  If you suspect though that you may have lost a little "something," that's probably why.  The only way to be certain is to get a new 2.2 mH ZOC and drop it in. It's sort of a shame, but in a pinch a guy's gotta do what a guy's gotta do.  Good luck! 

-Bob

[ooheadsoo]

ooheadsoo,

Yes, we want to get rid of that inductor if...it happens to be a steel-laminate core device.  I don't remember so I'll have to go back and look at the schematic.  Specifically, if it's a "Sledgehammer" model (marketed by Madisound) - it needs to go.  I'll let you know the value ASAP.

Carl V,

Same as above.  Although, while the woofers of the AV Series are more sensitive than those of our MRS line, they have nowhere the excursion capability of those aluminum cone SEAS units.  That may be part of the problem as the AV stuff was never capable of the same SPLs.  But then, you don't need as much juice to drive them either.  Everything in engineering is a trade-off.  Nevertheless, I can guarantee those inductors aren't helping one bit.  PM or e-mail me and we'll get it all worked out.

-Bob

Bob, it does appear to be one of those Madisound sledgehammer steel-laminate inductors.  Both Carl V and I have the AV-2 speakers.

[Aether Audio]

ooheadsoo & Carl V,

That inductor is 1.4mH.  If you're in a hurry you could try a large gauge air-core coil.  It should use at least 16AWG.  That would work fine and then saturation & hysteresis will never be a problem again.  Otherwise, we'll have to wait for the Mundorf pipeline to start flowing.  As soon as they start showing up I let everybody know.

Take care,
-Bob

[ooheadsoo]

Bob, do you personally see any advantage in waiting for the Mundorf inductors?  It also seems that 1.4mH inductors are not readily available, with most being 1.2 or 1.5. 

[Aether Audio]

ooheadsoo,

Nah...No reason to wait.  The inductance value isn't that high that you need to get as low of a DC resistance as needed in the aluminum SEAS woofer case.  We need that steel core for them as, depending on the model, the inductance is almost twice to 4 times the value as what's in the AV-2s.  That makes for too much wire/resistance if you go air-core.

You could use a 1.5mH, it would scarcely make a difference.  Heck, you could take the outer binding tape off and remove about 10 turns and you'd be just about at 1.4mH - if you really want to sneak up on it a little closer.  I say all this because the woofer circuit is nowhere near as sensitive to component value variations as the tweeter circuit.  If we were talking about the High Pass, I'd say you need to be sure to use the exact same values.

-Bob

[Karsten]

I'm not wasting my time here while waiting for the Mundorf components to arrive. Doing quite a bit of capacitor testing. The differences are actually not dramatic, not sure that I would be able to tell in a blind test which is which between the quality ones. The inductor upgrade was dramatic, but that was also a matter of replacing an inferior component, which was not doing a proper job.

So far I'd say that the Sonicaps are doing a pretty good job. Bob has been using these for quite a while and I wont nag him for this 

Those impatient to get the upgrade or a new set of SP speakers would probably not do a whole lot of compromise (If any) in a Sonicap based crossover with the right quality Mundorf series inductor on the woofer circuit.

I'll get back with further findings...

Karsten

[StevenACNJ]

I read this thread with great interest.

My speakers (not SP Tech) have a low pass filter feeding 8" Seas Excel drivers & the low pass filter has the following Madisound Sledgehammer Inductor - 10mh & .376 DCR

I have looked around and can find other types of inductors in the 10mh value but the DCR value is always higher.

I have contacted Madisound &  E-Speakers for another solution but they said no.

Any assistance in sourcing a better inductor will be appreciated.

Thanks

[Karsten]

Steven,

10 mH is ready available from Mundorf as standard value. If you can find the space, the t106 transformer core with a DC resistance of .22 ohm should work great.

Regards,
Karsten

[Aether Audio]

StevenACNJ,

A reliable source has informed me that Parts Express carries a pretty good coil.  Just do a search on their site for "Erse inductors."  I can't vouch for them personally, but they look pretty good.  Then again, so did the Sledgehammers and look what that got us.

As you can verify, finding a good, readily available source for power coils in this country is not easy to do.  Sure...if you want to have one custom made for you by any of the big transformer companies  - no problem-o.  But then, what are you going to do with the other 998 pieces that you have to buy to get them?

Good luck,
-Bob

[StevenACNJ]

Bob & Karsten

Thank you for the valuable information.

Getting the Mundorf T106 inductors will be at the least very expensive - if not impossible.

As you said, not many options out there.

Parts Express does seem to have two possibilities:

Erse 16G Super Q Inductors (specs are close to my current Sledgehammer)
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=312

Jantzen 14 Gauge C-Core Toroidal Inductors (DCR is lower than Erse & Sledgehammer)
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=384

Both seem to variations of an iron core design.

[Rick Craig]

I usually refrain from posting in the circles of other manufacturers but this is something that concerns myself as well as some of the other speaker manufacturers here that use the Sledgehammer inductors. A few years back these inductors as well as several others were tested in an independent magazine review. The Sledgehammer inductors were found to be second to air cores in terms of saturation and distortion. This obviously contradicts what Bob is saying so I've asked him to show some test results. The tests are easy to perform and there's no voodoo involved here - either they work in a linear fashion or not.

If you're considering replacing these inductors keep in mind that any change in d.c. resistance will also change the frequency response and bass tuning of your speaker. The amount of change can easily be modeled and / or measured. In some cases (as Bob noted) the impact may be minimal but there are designs in which it would detract from the speaker's performance.