Wish to add clarity and airiness to old Infinitys

[atomiccow]

I want to add some sparkle and clarity to some old Infinity 12" 3 ways that predate the EMIT tweeters. I was fond of EMITs and wondered if adding one of the electrostatic/ribbon tweeter at Parts Express would be a good choice? But maybe it needs to be matched up with a nice transparent midrange. Ive bid on real EMITS without much success.


My speakers are nice but they seem to be planted where they are and lack airiness.

This is my first visit here. Hope this is an appropriate question.

[wintermute]

Welcome atomiccow I think that is a perfectly reasonable question.

You could try my approach of just change it and see how it sounds but this would be frowned upon by most here..... I know why now, I didn't know about the complexities of crossovers back when I used that approach.

The basic problem is that your infinities crossover will have been designed to work well with your particular tweeter, if you replace it with another with different characteristics, you can't tell how it will behave.

due to differences in impedance, the old tweeter may have crossed over at say 3Khz as designed but the new one (with the same crossover) may actually cross at say 4Khz leaving a 1Kz gap... the reason this can happen is that the crossover freq is impedance dependent and two different tweeters though nomimally say 8 ohms can have very different impedances at different frequencies (generally rising with increasing frequency, some more rapidly than others).

Tony.

[atomiccow]

The basic problem is that your Infinities crossover will have been designed to work well with your particular tweeter, if you replace it with another with different characteristics, you can't tell how it will behave.

Don't know if it would help but both the midrange and tweeter have dials for them on the back. Maybe these are more like mini equalizers than changes in crossovers.

I'd probably have to take the try it approach.
It just makes me curious that most of the kits I see favor small dome tweeters even though the ribbon types are not especially expensive.

[scooby1]

hi atomiccow wintermute is right on the money , having read alot of this forum you will certainly get good info from most of the guys and girls ..
My idea however would be to go to perhaps a metal dome with a low fs to give you a wide range of impedence stabilityat probable xover freq eg..3k-4k.... it sounds as though your speakers have L-pads on both mid and tweet these should allow you to lesson or increase output of either
IMHO metal domes can give great SPARKLE to your highs and are well priced ...
One of the reasons ribbons are not used to frequently in two ways are the fact most have to be crossed over quite high, 3k -6k although in your case you could probably get away with it
I am just a newbie so please talk to others to get more and probably better advice
i figure with $30 seas metal dome it is a feasible choice to upgrade such old speakers
goodluck and above all ENJOY!
regards JULES

[wintermute]

If you have Lpads (the dials) then that is going to help somewhat, you at least won't have to worry about level mismatches so much (provided the tweeters are at least as efficient as the 12" which should probably be the case.

You may be lucky with the crossover freq too..... as I understand it the L-Pad presents a constant (usually 8 Ohms) impedance to the crossover so the impeadance of the tweeter may not be such an issue afterall..... Someone jump in if I'm way off here

So...... suck it and see may be ok in this case, but before you do, why don't you try adjusting the level of the tweeter with the L-Pad Dial, if you reduce the amount of attenuation you might just get the high end sparkle you are looking for without replacing the tweeter

Tony.

[atomiccow]

L pads eh?

Thanks guys.


These are pretty old and the tweeters and midrange are essentially paper. The tweeter is coated with a rubbery/plastic/tar looking substance.
I got a hunch it wouldn't be hard to do better.
Speaker tech hasn't improved much but in this case...
I think the lighter materials would make for more shimmery
invisible sound. So these are good tips and gives me some more confidence.

(It sounds ridiculous but I wish I could get an Ebay steal on some speakers JC Penney had for a short while in the eighties in their MCS line. They had soft dome tweeters and midrange. Exactly the sound I am after again and the bass was tight and full and the cabinets were Rosewood finish. Just beautiful. I figure no one wants to buy speakers from JC Penney bit these were up there with the better name audiophile three ways in dedicated stereo stores. Right after these they started selling crap again. I'd recognize them anywhere if I saw them.)

[wintermute]

I guess if the existing tweeters are severly lacking then even with a non optimal crossover (provided it isn't too low or too shallow a rollof) then a good tweeter will likely sound better even if it isn't optimal. Just be aware that there is the potential to sound worse, so don't spend a fortune you might want to check out zaph's tweeter test ---> http://www.zaphaudio.com/tweetermishmash/

If you have previously liked the sound of soft dome tweeters I'd steer away from metal domes. Personally I like soft domes but really don't like the sound of metal domes..... It's one of those preference things Ymmv though

Tony.

[David Lewis]

EMITs are very directional above 10Khz so they are difficult to get sounding 'airy'. I have a pair of Renaissance 90s and I now use an additional rear facing EMIT (as per Epsilon's) to improve overal dispersion. They are now very airy but it was a difficult route and in addition to the rear tweeter I also had to build a new external tweeter HP filter using same values as the internal Xover but with massive copper film inductors and huge ICW polypropylene caps. The much lower Q loss resulted in a whopping 3dB increase in sensitivity (which I corrected via an L pad)
The rear EMIT is actually 8dB down on the main tweeter but its contribution is quite astonishing.

Compared directly with B&W 800Ss my modded Infinty's come very close to matching the openness and air but are way ahead in sweetness and low level detail. (The ribbon strong points)

So yes, EMITs can be made to perform but it's difficult and they also need to be partnered by an EMIM otherwise it's near impossible to get a seamless transition from MF.



DL

[atomiccow]

Thanks for the Zaph tweeter test. I think I am going to abandon my ribbon idea and try their choice $30 solution.


Thanks also to David I am working off a home theater receiver and don't think it delivers the power required for EMITs anyway, so they would probably burn. With all the struggles I have endured putting this little budget, but semi spectacular theater together, I don't want to fight as hard as you had to to get the qualities I am looking for. At this price point I may be able to even bring in a new midrange and quite frankly destroy anything particularly 'Infinity" about these, but will probably end up with a better pair of speakers in the end. Their best quality is in the punch of the bass.

I just received the small SVS sub last night and just from adding that extra bottom it adds a lot to the perception of highs by virtue of contrast.

The help here was just great. I really feel I have something very specific to go after now and it will save me both money and grief.

What more can you ask from a forum?