Bass distortion before tweeter distortion with a monitor at high volume?


I am looking at getting a set of monitors for a second system in a small room (12' x 10') , but I would also like the flexibility to play them in my main system in a room that is larger (13' x 25') with cathedral ceilings.

Let's assume that the small speaker I end up with won't be able to produce enough volume without distorting in the larger room.  Most of what I have read indicates that a subwoofer would solve the problem.  My understanding is that I would want to high-pass the bass on the speaker before it reaches the point of distortion, solving that issue.

If that is true, that leads me to believe that generally the tweeter would not be distorting unless the volume is at a higher level.  Is this normally the case?  If not, it seems there would be no point to using the sub. 

To restate the question:  With a high quality monitor, is it safe to say that the tweeter can play at higher volume without distorting compared to the woofer?  I am speaking in general terms here - I am sure there are exceptions.  Thanks.
abnerjack

Showing 7 responses by abnerjack

sfall,

Thanks for the response and for the link. 

Here is what I don't understand.  If I try to play a small speaker in a too large room and have to supply too much power to it, it will distort.  True?  It just can't play that loudly.  So simply adding the subwoofer would not relieve the "strain" on the drivers, it would only provide more bass, but I would still have to live with the distortion, both from the woofer and from the tweeter (I'm talking about a two-way speaker).

If I did relieve the speaker of much of the bass load with a high pass filter, you are saying that you believe in most cases the part of the signal that goes to the main speaker would still be distorted?
sboje,


"If your speaker manufacturer uses the same tweeter in a larger 3 or even 4-way design, I would expect it to breeze along just fine."

Thanks for an excellent common sense answer.  To find a real world example, I went to Kef's web site and looked at their Q series, which utilizes the Uni-Q driver in the Q100 bookshelf.  The next speaker up in the line, the Q500, uses the same tweeter along with three other drivers for the frequencies below the tweeter's capability. 

In this example, it seems I could use the bookshelf along with a quality high pass and a sub(s) to achieve the flexibility I am looking for.  Sounds like a great solution.  I know I could take this exercise only so far , but can it be that I am actually having my cake and eating it to?  Thanks again. 
Thanks for all the interesting answers and differing points of view.  I don't have the knowledge of many of the experienced posters here and it is nice to be able to take advantage of it.   It seems it might be a good idea to look for a speaker/tweeter that has a lower THD?  Are there any graphs or measurements available to show this and it be worthwhile?
sboje,

Thanks for the chart and great info.

audiokinesis,

Excellent explanation of woofer distortion.

bob_reynolds,

I have read and appreciated many of your informative posts and your willingness to share your knowledge.

elevick,

I bet the Coincident's are great speakers and play well in a large room, but I am sure there are limits to the db it can achieve before it distorts.

The point of this thread is to discuss whether that distortion, which most seem to agree would occur on the bottom end first, could be relieved by high passing and allowing the sub to take the lowest range.

What do you think?
sfall,

I am not going to be pushing an amp hard.  To the contrary, I will be using a Bryston 4bsst2, which has 300w at 8 ohms, and can coast and drive ( I would think ) any 2 way monitor I choose.  Again, the point is, I want a small speaker that I can use in a small room primarily, and then occasionally  use it in a larger room where it will be driven harder, hence the break-up in the woofer.
sfall,

You once again make some good points, particularly the gap you mention between the reproducible frequencies of the sub vs the speaker and your statement that subwoofers are not woofers.

I use a pair of Rel T5's and they have crossover capability of 30hz to  120hz.  One of the criticisms I have heard regarding the Rels is that they in fact are not true subwoofers, but instead bass extenders.  Maybe that could work to my advantage in this scenario.

I will use the Kef LS50 as an example of what I am thinking.  The specs on the Kef show it going down to 47Hz.  Let's say that the high pass turns the "woofer" duty over to the Rel at 60 or 65 Hz, relieving the Kef of that responsibility.  Might that work?