Single Capacitor Two Way Crossover -- distortion??

[milezone]

The cutoff frequency is 20khz and there's a 12db difference in sensitivity. You're thinking inside the box... I understand all the basic points you're trying to suggest. Please consider what I'm suggesting. Or don't. If you can contribute to the question presented in my original post I'd be interested.

 

[milezone]

By adding in a inductor and a capacitor you can get a steeper slope but you will have more a complicated phase relationship with the driver. That is all beyond the scope of your ability from what I gather. You're not going to solve the phase relationship issues anyway so I suggest forget about those and just go for the crossover frequency you desire. Perhaps you just want 2 tweeters in each speaker. It will give you lots of brilliance. Parts express has a wide selection of pre-made crossovers for reasonable prices.

Why will two tweeters give more brilliance than one per speaker? Greater sensitivity?

 

[Doodski]

Why will two tweeters give more brilliance than one per speaker? Greater sensitivity?

Just more output. Nothing more than that. Not actually refining the upper top end of the hearing range. Just simply giving more decibels.

 

[March Audio]

The crossover frequency is 20khz and there's a 12db difference in sensitivity. You're thinking inside the box... I understand all the basic points you're trying to suggest. Please consider what I'm suggesting. Or don't. If you can contribute to the question presented in my original post I'd be interested.

Again you have totally lost me.

So you do want a 20kHz crossover, even though you said you didnt.

Oh hang on, do you mean you want the two drivers to play in parallel over a wide range of frequencies?

If so that categorically wont work. You will just have a total mess of summations and cancellations and directivity problems. You would still need to match sensitivities. You cant do this with a single cap.

Im afraid the guy in the audio shop should refrain from advising on subjects he clearly doesnt understand.

 

[milezone]

Again you have totally lost me.

So you do want a 20kHz crossover, even though you said you didnt.

Oh hang on, do you mean you want the two drivers to play in parallel over a wide range of frequencies?

If so that categorically wont work. You will just have a total mess of summations and cancellations and directivity problems. You would still need to match sensitivities. You cant do this with a single cap.

Im afraid the guy in the audio shop should refrain from advising on subjects he clearly doesnt understand.

Thank you. That's a lot clearer. Sorry for my unclear description in that case. So what is the risk of running two drivers in parallel over a wide range? Phase cancellation is the main one? How much of an issue is this audibly in a design like the one I mentioned? And I presume the issue is more audibly pronounced in the lower frequencies though maybe I'm wrong.

I'm still not certain I need to match sensitivities for the reason mentioned earlier, of upper hearing range frequencies being nearly inaudible at listening volumes, and the desire for more 'brilliance.'

 

[Mnyb]

Oh hang on, do you mean you want the two drivers to play in parallel over a wide range of frequencies?

If so that categorically wont work. You will just have a total mess of summations and cancellations and directivity problems. .

+1

The eventual distortion of the cap is the least of your problems. Just buy any .

You should design a real xover and not letting the drivers work in parallel over such a wide range .

You can have parallel drivers in bass because the drivers are very close compared to frequency the reproduce you can do parallel drivers for midrange in to an MTM diapolito arrangement this controls directivity with the correct xover and physical distances between tweeters and midrange drivers .

But the higher the frequency the closer the drivers must be , to avoid cancellations and comb filter effects .

Normal speakers have enough problems when using a real xover between two drivers in the region where both drivers contribute ,

Suppose you do this as a true 2 way with the Full range driver and a tweeter . If the FR driver is well behaved you could use a rather high xover frequency . There is a reason why almost no one uses full range drivers I think you are slowly discovering the reason as you want a tweeter

Suppose in PA speakers they get by with controlled directivity and long distance to the listener as you have stacks of speakers

 

[RayDunzl]

A clever(?) employee at an audio shop in Japan, Koizumi Musen

Im afraid the guy in the audio shop should refrain from advising on subjects he clearly doesnt understand.

Maybe there's a clue here:

http://www.koizumi-musen.com/fea/200221t500amk3/200221t500amk3.php

 

[milezone]

Looks painful... am I missing something?

 

[March Audio]

Thank you. That's a lot clearer. Sorry for my unclear description in that case. So what is the risk of running two drivers in parallel over a wide range? Phase cancellation is the main one? How much of an issue is this audibly in a design like the one I mentioned? And I presume the issue is more audibly pronounced in the lower frequencies though maybe I'm wrong.

I'm still not certain I need to match sensitivities for the reason mentioned earlier, of upper hearing range frequencies being nearly inaudible at listening volumes, and the desire for more 'brilliance.'

Yes phase cancellation as Mnyb describes above. The tweeter is still working at lower frequencies and its much louder than the woofer so you will get a significantly rising high frequency response. Hence sensitivities need to match.

But this is all rather moot as doing this just isnt going to work well. Dont do it

Single "full range" driver systems just dont work and just placing a tweeter in parallel without proper crossovers creates a whole world of problems.

 

[Blumlein 88]

I appreciate the suggestions and I know it's counterintuitive to all you folks. I still plan to explore the idea. And I remain curious about distortion related to capacitors in a crossover? Can adding more components in this context -- a passive crossover -- reduce distortion? Not to my knowledge though I'm not sure?

Just to throw out something why not just EQ your full range speaker to tilt up or shelve up just a bit around 5 khz. At least do it as an experiment to see what you think. A shelving filter would just bump things up around 5 khz and be flat at a higher level at any higher frequency.

I'm assuming something is being lost in translation from the shop worker you are listening to. It sounds like he doesn't know beans about how all this works.

 

[March Audio]

Maybe there's a clue here:

http://www.koizumi-musen.com/fea/200221t500amk3/200221t500amk3.php

....mmmm...the whole "super tweeter" thing.......

What people dont realise is the reason they hear a difference when they slap a super tweeter on top their speakers is not due to the extended ultra sonic response, its due to the super tweeter messing up and adding to the coverage below 20kHz.

 

[March Audio]

Just to throw out something why not just EQ your full range speaker to tilt up or shelve up just a bit around 5 khz. At least do it as an experiment to see what you think. A shelving filter would just bump things up around 5 khz and be flat at a higher level at any higher frequency.

I'm assuming something is being lost in translation from the shop worker you are listening to. It sounds like he doesn't know beans about how all this works.

You will still have directivity problems and most likely a very uneven on axis response.

 

[Blumlein 88]

Also tell us what speaker you have, and what tweeter you are considering to use. We can give more specific advice. And yes, the most likely good advice is don't do this.

 

[Blumlein 88]

You will still have directivity problems and most likely a very uneven on axis response.

Yes, you will. This whole thing is probably a bad idea.

Sounds like if anything the OP wants a 10 khz crossover to a supertweeter. It could even be done, but the insistence on doing it with one pure capacitor crossover is also indicative of the guy in the shop not knowing how things work.

 

[Mnyb]

Yes phase cancellation as Mnyb describes above. The tweeter is still working at lower frequencies and its much louder than the woofer so you will get a rising high frequency response. Hence sensitivities need to match.

But this is all rather moot as doing this just isnt going to work well. Dont do it

Single "full range" driver systems just dont work and just placing a tweeter in parallel without proper crossovers creates a whole world of problems.

I think op wanted a rising response , but the drives mismatch here is quite severe .

FR drivers beams at high frequency’s so unless you toe in and point them straight at you you have quit dull response ( one of many problems with an FR drivers )

 

[milezone]

I thought it was an interesting idea though I admit I was and am a bit skeptical. Still willing to give it a try though... what's the worst that could happen haha? The speaker is a Mark Audio MAOP 11. I may also purchase a Fostex FE168NS to compare the two. The tweeter I was considering is a Visaton G25FFL or for something fancy a Seas T35002. I once owned a pair of FE206EN speakers playing full range with Ribbon tweeters and a single capacitor filtering at around maybe 8000hz I recall. I liked the results quite a bit and am curious to revisit the idea hence my mentioning it in this thread.

In any case it's interesting to me how the cultures of Japan and the US differ so much and it's reflected in their cultural preferences and even things like diy speaker designs. The world would be a very boring place without that sort of variety of preference.

 

[Mnyb]

Yes, you will. This whole thing is probably a bad idea.

Sounds like if anything the OP wants a 10 khz crossover to a supertweeter. It could even be done, but the insistence on doing it with one pure capacitor crossover is also indicative of the guy in the shop not knowing how things work.

If you guys that can do the math , gets what FR driver and tweeter he intends to use ( I understand the general issue but is not an audio engineer) maybe the FR driver dies a natural death rigth about the 10k mark anyway.

 

[Juhazi]

Hey hey - here we have two universes in conflict!

To me it is obvious that milezone is deep in Japanese hifi culture where listening impression is all that matters. All other guys in the thread are thinking in the academic box of mathematics and physics. This dilemma can not be solved, forget it!

milezone - obviously you won't find the best sounding capacitor (or resistor as well) by asking at this forum! Don't waste your time.

Other guys - it just might be that masses of haphazard peaks and dips of interferences in treble, cone resonances and extra distortion can sound better to milezone or others, subjectively. That is an old trick with high-end hifi - remember whizzer cones in fullrages, Manger transducer, BMR, panel speakers, supertweeters of ´70s etc.

Whizzer cone here https://www.stereophile.com/content/rethm-maarga-loudspeaker-measurements

 

[solderdude]

You can safely add a super tweeter. You should, however, realize that the differences you will certainly be hearing do NOT come from your ability to hear ultrasonics but will be because of the added energy below 20kHz, combfilter effects, polar pattern differences and the ability of the tweeter to more accurately (faster) respond to high frequencies.

I am quite certain it will lead to improved SQ when combined with a full range speaker as full range speakers aren't as full range as most people believe it is.

 

[amirm]

milezone - obviously you won't find the best sounding capacitor (or resistor as well) by asking at this forum! Don't waste your time.

??? What is the best sounding capacitor and resistor?