Wanting to swap my Aaron ATS-5 tweeters for Vifa XT25

[bjc]

Hi all,

 

I'm in need of help in regards to swapping the tweeters in my Aaron ATS-5 main speakers.

This all started when Ditu's Aaron HMF-600's became available for sale and I was the intended buyer until I wrote my car off the following day and funds aren't there atm!

Anyway I had been trying to decide for some time about swapping the tweeters out for the Vifa XT25 which Aaron actually use in there top end (Hyperboloid) model.

The only thing I would like more with my ATS-5's is the tweeter although it is nice and mellow for my liking (newly owned them since 98!) they seem roll off at the top end just a little to much and I would like to try the XT25.

The Dali's I bought are just to bright for me and although they have great detail they are very fatiguing but also are only bookshelf speakers so maybe its a combination of that?

My friends Jamo are similar to me in that they are to bright and although this can seem good for HT with movies it is a killer on my ears very quickly.

 

I thought that if the Vifa's fit the cutout no probs or with little mod I'd be willing to buy a pair and make the crossover separate to match. Aaron use all electro caps so no big dollar stuff needs to be applied but I will need help for what crossover components to use?

 

I have photos of my model of ATS-5 but believe the standard tweeters were crossed at 5khz (as are the HMF's). I can supply pdf's of their crossover layouts as they provide them on there website.

 

Vifa sell a couple of different models in the XT25 though and I'm not sure which ones to use? They have the XT25TG30-04 and the XT25BG60-04 but was thinking of using the TG30?

 

My speakers have the specs are-

 

Freq Resp- (28Hz - 23kHz (+/-3db)

Power-(30 - 200 watts)

Sens-(93db)

Imp-(6 ohms)

and the design is of (Low Q Ratio)! Not sure the 93db sensitivity is correct but they are efficient and at least over 90db using fabric cone surrounds!

 

Can a 4ohm tweeter be used with the 6ohm system no problems though as this is out of my knowledge base?

 

I thought of just copying Aaron's crossover design from there HMF-600 Mk1/Mk2 which is also at 5khz with also what I think is a filter for the resonant freq?

 

Anyway all or any feedback is much appreciated and can add links, schematics or pics if needed.

 

Thanks,

Brett

[davewantsmoore]

You should not change the tweeters in your speaker unless you redesign the crossover filter.

 

The crossover filter also depends on the cabinet shape and mid/woofer response.    So even if you were able to copy the XO from the HMF, you will need to redesign the tweeter filter with respect to the different response of the midrange driver in the ATS-5  (vs the different mid driver in the HMF).

[bjc]

I was going to bypass the existing tweeters filters and make my own separately with speaker cable to the new tweeter if that's what you meant Dave or do you mean redesign the whole 3 way XO network?

 

Will XO the same freq for the XT25 at 5khz then will make no difference?

 

As I said this is outside my understanding but happy to learn basics!

[henry218]

just like to add that, most music information is below 5khz, you actually will hear more detail if the midrange band improves, although the tweeter definitely will add the harmonics and ambiance perception to it.

 

try to put some more bracing in your box (vertical brace where meets all sides of panels is the most effective, even if its just one) and add sound deadener from ebay (2-3mm bitumen pads) and apply it to the walls, you should hear more detail to your speakers than replacing the tweeters would be

[davewantsmoore]

I was going to bypass the existing tweeters filters and make my own separately with speaker cable to the new tweeter if that's what you meant Dave or do you mean redesign the whole 3 way XO network?

 

Ok.  If you're going to design your own tweeter filter to combine the tweeter with your current midrange, then that will be fine.

 

My point was that you cannot copy the tweeter filter from the HMF, as it is designed to blend with a different midrange driver.

 

If you are designing the filter yourself, then the impedance of the tweeter will be accounted for in your design, so it doesn't matter if the XT25 impedance is different from the original tweeter.

[davewantsmoore]

Will XO the same freq for the XT25 at 5khz then will make no difference?

 

Not sure I understand the question ?!

[davewantsmoore]

just like to add that, most music information is below 5khz

 

Don't forget that the rolloff of the tweeter is important here.     If the tweeter rolls off at 12 or less dB / octave below 5khz, then it has significant response in the midrange  (and it amplitude and phase will be very important).

 

 

than replacing the tweeters

 

Yes.   One comment I would make to the OP is while I don't know what tweeter you are changing from ....   it is the crossover filter (and not the tweeter) which will dictate the performance.     If you are thinking you are going upgrade your speaker by putting in an XT25 - then you should know that the performance is going to be all down to the filter which you design for it.    So much so, that assuming that the original tweeter is high quality and has a good filter designed for it  (big assumption) .... that the best you might hope for is to get the same performance.

 

 

(Again, assuming the original tweeter + filter is a good design) ....  If you put in a new tweeter, and you design a filter which is incorrect, then you may hear a very different sound to your old speaker.    You may like it, or hate it... but it won't be correct.

 

 

Sorry... just lots of words to say the tweeter filter is the most important bit in this puzzle.     Not trying to turn you off.

[davewantsmoore]

The BG is shielded, slightly higher sensitivity, and higher Fs

 

 

I've only used the other (TG) version.... but have used it a lot.    It's good for a 2 way speaker as it has a nice low Fs and good response in a waveguide/horn.    Great performance / $

[bjc]

I cant get specs on the original tweeter as its not stamped with anything and can only be bought from Aaron afaik?

 

XO specs though are are attached for both my ATS-5 and the HMF-600 as is the XT25TG30 specs.

 

Thanks for the help and insight so far. Both of you...

ATS-5Xover.pdf

HMF-600Xover.pdf

Vifa_XT25TG30-04.pdf

[bjc]

just like to add that, most music information is below 5khz, you actually will hear more detail if the midrange band improves, although the tweeter definitely will add the harmonics and ambiance perception to it.

 

try to put some more bracing in your box (vertical brace where meets all sides of panels is the most effective, even if its just one) and add sound deadener from ebay (2-3mm bitumen pads) and apply it to the walls, you should hear more detail to your speakers than replacing the tweeters would be

 

Thanks Henry,

 

The Midbass driver is in its own sealed box inside the cabinet and has dacron filling so not sure I can improve on this unless more expensive XO parts are used?

I watched someone elses topic on here with the ATS-5 where he braced the box and thought I may do the same but would prob only use 2-3 hardwood dowels across the cabinet if at all but this would be mainly for flex in the cabinet if there is any? I could always try some vice clamps to see if supporting the sides makes a difference in sound but this would be the bass region up to its 800hz XO or thereabouts.

[henry218]

you would be surprised how the lower distortion to the bass improves your midrange

[Zaphod Beeblebrox]

The ATS-5 is best improved by the following:

* Damping the internal panel walls with Bostik Sound Deadening Panels. Cover every surface.

* Placing some Dacronâ„¢ or wool inside the box.

* Replacing the existing bi-polar electrolytic caps with decent plastic caps.

Forget about replacing the tweeter with something different. The learning curve is too steep and the payoff too small, given the value of the speakers. IOW: You'll need to study up on crossover design, invest in test equipment, learn how to use that test equipment, THEN design your own crossovers.

It ain't worth it.

OTOH, the mods I suggested (which I have performed to dozens of ATS-5 speakers) is guaranteed to return excellent results from top to bottom.

[bjc]

I have most test equipment (calibrated mic, DATS) but the XO change will only be for the tweeter.

 

When you say "some" dacron, do you mean line the walls, half fill, fill lightly packed etc?

 

Do you use sound deadening material instead of braces so there are no visible screws as this does not bother me with the age of them now and would prefer bracing over a deadening material?

I do have plenty of flash tac downstairs also that I could use if need be!

 

I am still leaning towards a tweeter replacement unless a cap/resistor change on the existing tweeter can fix the lack of top end as this is my only real niggle with them after owning for so many years!

I have done a previous change of the resistor and cap on one of the mains as the cap for the tweeter died over a year or so ago which was a costly fault find ($176 a tweeter diaphram) for me destroying two tweeters instantly before I gathered it was the XO...

[henry218]

if you got the gear, then go ahead, we will help you along the way if needed.

while at it its prob better to move the xover freq to 2.5-3khz, as i think the 5khz is prob more on the limited tweeter capability rather than exceptional midrange response

[henry218]

The ATS-5 is best improved by the following:

* Damping the internal panel walls with Bostik Sound Deadening Panels. Cover every surface.

* Placing some Dacronâ„¢ or wool inside the box.

* Replacing the existing bi-polar electrolytic caps with decent plastic caps.

Forget about replacing the tweeter with something different. The learning curve is too steep and the payoff too small, given the value of the speakers. IOW: You'll need to study up on crossover design, invest in test equipment, learn how to use that test equipment, THEN design your own crossovers.

It ain't worth it.

OTOH, the mods I suggested (which I have performed to dozens of ATS-5 speakers) is guaranteed to return excellent results from top to bottom.

i agree, as he already done it before, i would suggest to follow his suggestions

btw, where can we buy the bostik? is it bostik 8104?

[davewantsmoore]

I cant get specs on the original tweeter as its not stamped with anything and can only be bought from Aaron afaik?

 

In order to modify the XO just on paper.... you will also need the data from the original tweeter.

 

Otherwise, you'll need to take acoustic/electrical measurements  (like in normal speaker design)

 

What you're proposing to do is essentially designing a new speaker   (ie.  probably much more complex than you expected).

 

 

Is anything wrong with your current tweeter?

Has anyone else done this 'upgrade' before with documented procedure and results (which you could copy)?

[davewantsmoore]

not sure I can improve on this unless more expensive XO parts are used?

 

 

Hmm....  You should focus on the response of the filter, rather than the quality of the parts.     Parts quality can matter sometime, or a little....  the actual response of the filters matters a lot, always.

 

 

EDIT:   OOoo... Read the whole thread.   Def. change electrolytic caps with new ones (bonus points = different type).

Edited May 19, 2014 by davewantsmoore

[davewantsmoore]

I am still leaning towards a tweeter replacement unless a cap/resistor change on the existing tweeter can fix the lack of top end as this is my only real niggle with them after owning for so many years!

 

Post a measurement on tweeter axis so we can see what you're talking about   

[davewantsmoore]

while at it its prob better to move the xover freq to 2.5-3khz, as i think the 5khz is prob more on the limited tweeter capability rather than exceptional midrange response

 

Woah.    Moving the XO frequency by an octave just on a whim is   

 

5khz was chosen for a good reason  (the tweeter has too wide a response an octave lower)   .....    If you were to move it, you will need to redesign the midrange XO also ....  but you also will be playing with the off axis response of the speaker....   So even if you reproduce the onaxis response of the speaker identically to the original ATS5 .... it will sound completely different.

[henry218]

Woah. Moving the XO frequency by an octave just on a whim is

5khz was chosen for a good reason (the tweeter has too wide a response an octave lower) ..... If you were to move it, you will need to redesign the midrange XO also .... but you also will be playing with the off axis response of the speaker.... So even if you reproduce the onaxis response of the speaker identically to the original ATS5 .... it will sound completely different.

i could be wrong, at that freq, the midrange is on the border of breaking up and losing its comfort

[davewantsmoore]

i could be wrong, at that freq, the midrange is on the border of breaking up and losing its comfort

 

Yes, but that is very much less audible the the large changes to the frequency response you will get by moving the XO downward.   The mid becomes directional above about 1khz.    If you lowered the crossover frequency to 2.5khz .... then because the tweeter has a much wider response than the mid at these frequencies, you are going to be increasing the output offaxis in this octave (2.5-5khz) by many dBs... and this will completely change how the speaker sounds.

 

So, the cone breakup is almost irrelevant.... because you have no choice, if you want this offaxis response, then you must run the mid driver up to 5khz ......    If you want a different off axis response.... then that's fine.... but it will sound quite different the original speaker   (don't make the mistake of blaming the change on reduced cone breakup).     However the offaxis response you'll get my simply moving the MT XO downwards .... will be bad.    The mid will narrow above 1khz.. but widen as it transitions to the wide tweeter at 2.5-3khz ... and then narrow again as the tweeter becomes directional.

 

 

 

FWIW.  I use a 4" midrange driver between 1khz and 6khz.

 

If it does anything to demonstrate just how important the offaxis response of a speaker is ....   the only reason my speaker even has a midrange driver, is to get the correct off axis response.    The lower mid (8") and tweeter (0.75") could meet each other if you really pushed it ..... but the frequency response offaxis would be less than good.

 

 

Sorry.  I'm yammering again   :-W

[Zaphod Beeblebrox]

i agree, as he already done it before, i would suggest to follow his suggestions

btw, where can we buy the bostik? is it bostik 8104?

Yep. 8104 is the stuff. I glue it in place using silicon adhesive. Here in Sydney, I usually buy from Express Industrial, though a call to Bostik Australia may elicit other sources.

[Zaphod Beeblebrox]

I have most test equipment (calibrated mic, DATS) but the XO change will only be for the tweeter.

It's still a big job.

When you say "some" dacron, do you mean line the walls, half fill, fill lightly packed etc?

A light fill is usually adequate.

Do you use sound deadening material instead of braces so there are no visible screws as this does not bother me with the age of them now and would prefer bracing over a deadening material?

Bracing AND Sound Deadening Panels would be ideal, but, IME, the Sound Deadening Panels work extremely well. Thing is, by controlling panel vibration, the sound of the entire speaker is cleaned up (including the HF).

I do have plenty of flash tac downstairs also that I could use if need be!

Good for you. I've never used it on the ATS-5. I have only ever used Bostik Sound Deadening Panels with loudspeakers. I use the product, because it is designed to do exactly what I want it to do. It's well priced and easy to use.

I am still leaning towards a tweeter replacement unless a cap/resistor change on the existing tweeter can fix the lack of top end as this is my only real niggle with them after owning for so many years!

I'll say again: Fix the basic problems with the speaker FIRST, then attend to other issues. By dealing with vibration control, you'll clean up everything in the speaker. It won't cost a fortune and it won't cost you a lot of time and effort and will pay big dividends.

I have done a previous change of the resistor and cap on one of the mains as the cap for the tweeter died over a year or so ago which was a costly fault find ($176 a tweeter diaphram) for me destroying two tweeters instantly before I gathered it was the XO...

Change ALL the crossover caps for plastic film types. You will not be sorry.

[henry218]

Yep. 8104 is the stuff. I glue it in place using silicon adhesive. Here in Sydney, I usually buy from Express Industrial, though a call to Bostik Australia may elicit other sources.

thanks zaph

[BATMAQN]

It's still a big job.

A light fill is usually adequate.

Bracing AND Sound Deadening Panels would be ideal, but, IME, the Sound Deadening Panels work extremely well. Thing is, by controlling panel vibration, the sound of the entire speaker is cleaned up (including the HF).

Good for you. I've never used it on the ATS-5. I have only ever used Bostik Sound Deadening Panels with loudspeakers. I use the product, because it is designed to do exactly what I want it to do. It's well priced and easy to use.

I'll say again: Fix the basic problems with the speaker FIRST, then attend to other issues. By dealing with vibration control, you'll clean up everything in the speaker. It won't cost a fortune and it won't cost you a lot of time and effort and will pay big dividends.

Change ALL the crossover caps for plastic film types. You will not be sorry.

Listen to the Guru he doesn't talk shite.