Is paying $4,000 for a pair of speakers with one tweeter worth it?, confused

[HTHOLIC]

Hi, everyone audioholic experts, Well I presume after all these years of learning lol.


I have a 3500-4500 cubic feet room and am confused about tweeters

No, I am not confused about what a tweeter is, I do know that a tweeter outputs a high frequency sound, but my confusion is regarding the fact that a lot of speakers may have double or even 3 or 4 woofers but only one tweeter.


My fear is that I will buy a speaker such as the 1266 se from RBH, or you can say the onix reference 3 and one tweeter will not be enough.

To add to the confusion is the fact that many speakers don't have more than one tweeter because of lobing and other concerns.

Every cheap but valuable , ie svs,axiom,onix etc has one tweeter. Is paying for a $4,000 speaker with one tweeter worth it. Note the speakers are floorstanding and come in pairs.

My understanding was that the more drivers, the more output and less stress so that I should get a speaker with more than one tweeter.

Axiom audio suggested the same thing but I am not sure if I need it, because of my room size.

In any case, the RBH center speaker the 661 only has one tweeter also.

So if tweeters are important, ie scanspeak, why do speakers have more woofers than tweeters. Some speakers have mid-woofers and ultra high frequency tweeters for sounds above 20khz, but still only one main tweeter.

The RBH 6000/R has 4 woofers but only one tweeter.

Am I going to lose out?,

 

[Joe Schmoe]

Except for multidirectional speakers (eg Def Tech bipolars), very few speakers at any price have multiple tweeters. One of the only exceptions I can think of is the Macintosh towers.
(FWIW I have heard several speakers costing over $4000/pr, but none that struck me as being worth that much.)

 

[Swerd]

... my confusion is regarding the fact that a lot of speakers may have double or even 3 or 4 woofers but only one tweeter.

...My understanding was that the more drivers, the more output and less stress so that I should get a speaker with more than one tweeter.

...To add to the confusion is the fact that many speakers don't have more than one tweeter because of lobing and other concerns.

The simple explanation is that most tweeters are more sensitive (louder) than most woofers or midwoofers. In a 2-way speaker, the crossover often has resistors added to the tweeter section to reduce its loudness to the same level as the woofer. Another way to deal with uneven woofer and tweeter sensitivity is, as you pointed out, to add one or more woofers. Each additional woofer can add, in theory, about 3-6 dB of response to the bass. Because tweeters are usually louder than woofers, adding extra tweeters isn't needed.

Most speaker designers avoid using multiple tweeters because it introduces complicated interference patterns that can be very difficult to work with and still get smooth treble response. It is much simpler to have one single source of treble sound. This same problem does exist with multiple woofers, but it is not so difficult to deal with, especially if they are in an MTM layout.

It is up to the speaker designer to make sure that the overall balance between woofer(s) and tweeter is even, flat accross the audio range. As long as that is good, you will lose nothing.

 

[HTHOLIC]

I am confused about a tweeter's output

I am confused about output and soundstage.

So, the reason for one tweeter is that it creates a very strong, high spl output and multiple woofers balance that out?

When is one tweeter not enough?

 

[Joe Schmoe]

When is one tweeter not enough?

Never. One tweeter is always enough.

 

[HTHOLIC]

Okay here's the audio explanation, from axiom's president

Adding more tweeters (and midrange drivers) and/or woofers increases a speaker's power handling and ability to play cleanly in bigger rooms at very high playback volume without distortion.

That is the main design reason for increasing the number of drivers in a speaker. For example, if you go to the page for the Axiom M60 v2 tower speaker and scroll down,

http://www.axiomaudio.com/m60ti_main.html

. . you'll note that the M60 has two woofers, one midrange driver and one tweeter, and that its "Maximum Amp Power" (power handling) is rated at 250 watts per channel.
Click on "Compare all Floorstanding Speakers" and you'll see that the Axiom M80 v2 tower adds an additional midrange driver and a second tweeter, for a total of six drivers, thereby increasing its power handling to 400 watts per channel. In fact, the M80 will routinely handle upwards of 700 watts per channel in rooms and play at near deafening levels before dynamic compression kicks in.

All drivers are basically reciprocating electric motors, air pumps if you will, powered by magnets and voice coils of wire that move rapidly back and forth to generate sound waves at appropriate frequencies and loudness. As you increase the power and the drivers have to "work" harder (pump more air, producing greater loudness) they heat up and move farther back and forth.

Eventually, every speaker has a limit both in terms of thermal compression from heat and dynamic compression because the voice coil moves as far as it can from the magnetic gap and can move no further. Thus it can't produce any more volume or output. With the M80 in our test anechoic chamber, that point is reached at about 400 watts of input and 118 dB SPL output. The latter is approaching the threshold of pain in terms of loudness. In a room, it would be significantly higher in output.

Look at our simpler bookshelf speakers like the M2 v2, which uses a single woofer and tweeter. Its power handling is 150 watts. By adding a second identical woofer/midrange unit, the M22 v2 handles more power (200 watts) and plays louder in bigger rooms, although it doesn't approach the M60 or M80 in bass output or power handling.

Lobing occurs when multiple drivers are used and may result in some cancellation of certain frequencies common to both drivers. It is overrated in terms of audible effects.

And yes, if a large tower speaker uses only one tweeter, it will have more limited power handling and output capabilities compared to a similar speaker with more drivers.



The part the confuses me, is that the tweeter on the RBH will probably never go into thermal compression.

SO IS adding a tweeter just to increase the loudness.

 

[Swerd]

I am confused about output and soundstage.

Output and soundstage are not directly related. Output is easily measured and adjusted. In this case, the woofer and tweeter output should always be as even as possible. A frequency response curve readily shows this.

Soundstage is very different. It usually requires a pair of speakers operating in stereo. I don't know of any measurement or graph that can directly show soundstage. What affects soundstage is the off-axis response of all the drivers in the speaker, but most important, in my opinion, is the off-axis response of the woofer(s) at the highest frequencies they operate at before the crossover rolls them off. To understand that, you need to see a graph of the woofer's frequency response, without any crossover in place, measured on-axis, and 15, 30, and 60 degrees off-axis. The crossover frequency should be at a frequency where the woofer's off-axis (let's say 30 degrees off-axis) response is still nearly as good as the on-axis response. If the crossover frequency is too high, where the off-axis response falls off too much, then soundstage suffers.

Manufacturers of woofers usually provide that info for their raw drivers, but completed speaker manufacturers rarely show that info.

Most 1" dome tweeters usually have good off-axis response until you get into the very high frequencies above 15 kHz. The midrange, where the crossing over takes place, is much more important for soundstage.

So, the reason for one tweeter is that it creates a very strong, high spl output and multiple woofers balance that out?

Yes

When is one tweeter not enough?

As far as I'm concerned, never. If a speaker's woofers are too loud for a given tweeter, get a different tweeter that is loud enough. There are some (very few) designers who like playing with large vertical arrays. They are almost always very expensive, and I don't understand what their appeal is.

 

[Swerd]

Adding more tweeters (and midrange drivers) and/or woofers increases a speaker's power handling and ability to play cleanly in bigger rooms at very high playback volume without distortion.

That is the main design reason for increasing the number of drivers in a speaker. For example, if you go to the page for the Axiom M60 v2 tower speaker and scroll down,

http://www.axiomaudio.com/m60ti_main.html

. . you'll note that the M60 has two woofers, one midrange driver and one tweeter, and that its "Maximum Amp Power" (power handling) is rated at 250 watts per channel.
Click on "Compare all Floorstanding Speakers" and you'll see that the Axiom M80 v2 tower adds an additional midrange driver and a second tweeter, for a total of six drivers, thereby increasing its power handling to 400 watts per channel. In fact, the M80 will routinely handle upwards of 700 watts per channel in rooms and play at near deafening levels before dynamic compression kicks in.

All drivers are basically reciprocating electric motors, air pumps if you will, powered by magnets and voice coils of wire that move rapidly back and forth to generate sound waves at appropriate frequencies and loudness. As you increase the power and the drivers have to "work" harder (pump more air, producing greater loudness) they heat up and move farther back and forth.

Eventually, every speaker has a limit both in terms of thermal compression from heat and dynamic compression because the voice coil moves as far as it can from the magnetic gap and can move no further. Thus it can't produce any more volume or output. With the M80 in our test anechoic chamber, that point is reached at about 400 watts of input and 118 dB SPL output. The latter is approaching the threshold of pain in terms of loudness. In a room, it would be significantly higher in output.

Look at our simpler bookshelf speakers like the M2 v2, which uses a single woofer and tweeter. Its power handling is 150 watts. By adding a second identical woofer/midrange unit, the M22 v2 handles more power (200 watts) and plays louder in bigger rooms, although it doesn't approach the M60 or M80 in bass output or power handling.

Lobing occurs when multiple drivers are used and may result in some cancellation of certain frequencies common to both drivers. It is overrated in terms of audible effects.

And yes, if a large tower speaker uses only one tweeter, it will have more limited power handling and output capabilities compared to a similar speaker with more drivers.

The part the confuses me, is that the tweeter on the RBH will probably never go into thermal compression.

SO IS adding a tweeter just to increase the loudness.

While this answer from axiomaudio is correct, pay attention to the very first words "to play cleanly in bigger rooms at very high playback volume without distortion."

Just how big is your room and how loud do you plan on playing your speakers? I think you may be worrying too much about this. The M-60s will be plenty loud enough. Don't go for a design that needs to use two tweeters just to get loud enough.

Remember that 88-90 dB is quite loud, and for most speakers with reasonable sensitivity, that comes at about 1 watt measured at 1 meter away.

 

[WmAx]

What affects soundstage is the off-axis response of all the drivers in the speaker, but most important, in my opinion, is the off-axis response of the woofer(s) at the highest frequencies they operate at before the crossover rolls them off.

If by soundstage, you mean the spatial depth perceptions created by the phantom reflections from walls, then this is probably not correct. The band that has the most effect in this perception is the upper treble bandwidth(10-15khz). This is directly related to the wavelength in air vs. the ear structure size; in relation to directing/filtering high frequencies for such perceptions. The ear structure has insufficient physical dimenions to effectively process midrange to the same degree as compared to treble, in regards to this aspect.

Of course, you may be referring to something else. The term 'soundstage' has always seemed rather ambiguous to me.

Most 1" dome tweeters usually have good off-axis response until you get into the very high frequencies above 15 kHz.

The typical dome tweeter has substantial (5-6 db) roll off by 8-10khz at just 45 degrees off axis.

-Chris

 

[Swerd]

Chris, thanks for your ideas and definitions. They might help to clarify an answer for the OP.

I tend to use the terms soundstage and imaging interchangably. I have never heard a formal definition for either of these terms, so I wasn't sure what the OP was really asking. I tried to answer him by mentioning various things on speakers that can be changed that affect image perception in general.

As far as off-axis tweeter performance, you are right. I was thinking about 30 degrees or less off-axis performance, but I didn't specify that .

 

[Swerd]

HTHOLIC did we answer your question?

Or did we loose you?

Sometimes these threads wander just a bit .

 

[fmw]

I am confused about output and soundstage.

So, the reason for one tweeter is that it creates a very strong, high spl output and multiple woofers balance that out?

When is one tweeter not enough?

When you want to extend the directionality of the high frequencies. As you may know, the high frequencies are very directional so you should have a single tweeter aimed at your head. It is possible to put an array of tweeters pointed in slightly different directions to present a proper mix of frequencies when heard by more than one listener.

I should mention that the price of speaker systems often doesn't reflect their performance. High end speaker makers for the most part are small companies so their products aren't priced based on production costs. They are usually priced to cover overhead with a profit base by simply dividing the number they expect to sell by the revenue they need.

 

[HTHOLIC]

No you didn't lose me, it is a bit confusing though

I am glad that people are responding via audioholics, It was hard to find a answer all over the internet.

I notice there are line-array speakers such as from RBH as I mentioned earlier.

I have to admit its a bit confusing , when talking about sound stage and different frequencies.

Take the RBH 6000/R vs. the RBH 6100/R.

The RBH 6000/R has 2 woofers, a tweeter in the middle and then 2 woofers below it in a vertical line. The RBH 6100/R by contrast has the same layout but 3 tweeters , each sandwiched between the woofers.

Which begs the question, why the huge difference, note that it is an inwall speaker.

Although its inwall, they make the T system with multiple woofers and tweeters.

I wanted to set up a system where the center channel would have 2 woofers, 1 tweeter and the floorstanding left and right would be the same thing but with a subwoofer portion.

The surround sides would be bipole and the surround back normal bookshelfs.

Its a great question because folks like onix are coming out with a floorstanding speaker with 21 drivers

So if the only reason is to point the tweeter to another person why don't people use seperates. I know gene on audioholics prefers line array.

Again, thanks for the advice.

 

[Swerd]

Now I'm confused too

Those RBH inwall models are new to me, and I suspect most other people reading here. I wonder if anyone has heard these. You may be the first, if and when you get them.

I'll admit that I know nothing about inwall speaker design and how similar it is to more standard out-of-wall speakers. I've always wondered whether inwall designs take into account the added bass response that comes from having the speaker's front baffle inline with the wall. I suspect that some of the cheaper "builders' grade" inwall speakers ignore this aspect. None of the inwall speaker systems I've heard are anything like those RBH models.

RBH is considered a respectable manufacturer. You're going to have to take that leap of faith that they have considered the various problems of designing inwall speakers and know what they are doing.

As far as vertical line arrays with multiple tweeters, you are also entering alien territory for most people here - including me.

That 6100 model with the 3 tweeters interspersed among the 6½" drivers is a layout that I have never seen before, and would be considered by most amateur designers as violating some widely accepted principles about tweeter placement. Generally, multiple tweeters should be placed as close to eachother as possible.

However, as I said before, when it comes to inwall speakers, there are some different principles involved, and I am not qualified to give any advice about them.

Good luck and please tell us what come up with.

 

[gene]

Those RBH inwall models are new to me, and I suspect most other people reading here. I wonder if anyone has heard these. You may be the first, if and when you get them.

I'll admit that I know nothing about inwall speaker design and how similar it is to more standard out-of-wall speakers. I've always wondered whether inwall designs take into account the added bass response that comes from having the speaker's front baffle inline with the wall. I suspect that some of the cheaper "builders' grade" inwall speakers ignore this aspect. None of the inwall speaker systems I've heard are anything like those RBH models.

RBH is considered a respectable manufacturer. You're going to have to take that leap of faith that they have considered the various problems of designing inwall speakers and know what they are doing.

As far as vertical line arrays with multiple tweeters, you are also entering alien territory for most people here - including me.

That 6100 model with the 3 tweeters interspersed among the 6½" drivers is a layout that I have never seen before, and would be considered by most amateur designers as violating some widely accepted principles about tweeter placement. Generally, multiple tweeters should be placed as close to eachother as possible.

However, as I said before, when it comes to inwall speakers, there are some different principles involved, and I am not qualified to give any advice about them.

Good luck and please tell us what come up with.

CinemaSITE Review
http://www.audioholics.com/reviews/speakers/floorstanding/rbh-sound-cinemasite

RBH T-2p Review
http://www.audioholics.com/reviews/speakers/floorstanding/rbh-sound-t-2

RBH T-30LSE Review
http://www.audioholics.com/reviews/speakers/floorstanding/rbh-t-30lse

HTHolic, you've started numerous threads on this topic for the past few months making one wonder if you are really serious about this topic and buying speakers, or if you just like to rehash the same topic over and over again.

Why not call the manufacturer in question and ask about their design philosophy. Making sweeping generalizations about how speakers should be designed, the # of drivers that should be used, etc is fruitless. There is no set formula and a designer has to base their design on the least amount of compromises while making a product intended for a specific purpose or market need they are going after.

 

[j_garcia]

I have a room about that large and I have never had a problem with single tweeter speakers. I really REALLY don't get where you are going with this one...

 

[HTHOLIC]

I guess you can say that its a curiousity, but a question that begs to be answered

It begs the question, you know

seeing multiple woofers, so its natural to ask why not multiple tweeters.

I am SERIOUS about obtaining speakers, it just the LCR speakers that I am concerned about having enough output and whatever.

Gene prefers the line array and says is superior to conventional designs although it may be personal preference.

The 6000 has one tweeter while the 6100 has 3 , which begs questions

9 midrange panel/tweeters for the reference 2.

Ya, that wasn't my comment gene about the design of those RBH in wall speakers, however that was a very interesting post.

Maybe I should ask RBH about the difference. Perhaps the 3 tweeters would come in handy IF - you have one person sitting in the theater taller than the other. Again,

if I am going to spend $5500 on 2 floorstandings and a center with one tweeter I just want to make sure its allright, and be curious about the other designs out there and see if its better or an improvment. Keep the discussions rolling.

 

[gene]

You're wasting your time with RBH speakers. You need these:

http://www.kpbj.com/images/general/CoverStory_2001pg10.jpg

They are far superior to any multi tweeter/woofer speaker system on the planet. I am sure they will play plenty loud too

 

[HTHOLIC]

Lol, but its outdoors where room acoustics isnt all that worth it

I remember you saying room acoustics, isnt that important outdoors.

My real question should be about space I guess, 4500 cubic feet and wondering if I should get something other than the 1266 se/r with the 661 SE/R.

My only other RBH option would be the T system or the T in wall.

And the only difference is more tweeters and woofers in the line array. Lol, if it werent for gene's reviews I may have never ask this question.

Now, gene can you shed some light on line array,

I note that the review on the in wall was about the S-6100 not the S-6000 with one tweeter.

Its the Reference series version that I am referring to.

Perhaps audioholics should have a basic introudction article about this tweeters and woofers and directionality and soundtage.

 

[markw]

An alternative

Call/Write RBH with your concerns. Apparently they feel their designers did a good job.

What you're doing is akin to arguing with the pharmacist that this tiny pill looks too small to do any good when the pharmacitucal company produced in in specific dosages and the doctor prescribed it in that dosage.

All in all, I'd say they do a pretty good job of explaining things here. Remember, this isn't a credit course in a college. This is a consumer forum with more emphasis on education than others I've encountered. if you need to get more into the technical ends of this hobby, there are courses in colleges and tech schools abd books in the library that cover this stuff in greater detail.

...but that might require a little more commitment on your part than posting in a forum.

Let us know what RBH says in response to your queries.