You can never have too much power......

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Originally Posted By: OVERK1LL

The range for the woofers (subs) that I'm using is 25Hz - 2,800Hz if that helps?


There's NO WAY that driver is reaching 2.8khz in an effective sense. If that driver was still flat at 500hz, I'd be shocked. And it's not designed for those frequencies, either.

That may be its advertized absolute frequency range. But +/- 3db from nominal, which is how speakers are employed - NO WAY. Many tweeters are capable of emitting a 20hz signal, but at levels so far below their nominal that they are virtually inaudible. That's the roll off point of which I was referring above. And you don't want that driver working that far down, even if it could. The same applies to LF drivers.

What a crossover does is roll off the signal electronically, so the driver is not forced to reproduce frequencies that it is not designed for, and which adversely affects output at design frequencies. You don't want tweeters working bass, and you don't want woofers working treble. You certainly don't want a subwoofer working at 2.8khz . . . or even 280hz for that matter.

The original CV woofer I'm sure didn't extend as low, but was able to reach higher, to cover the Xover gap into the mids a little better. I suspect that the designer gave up a little on the bottom, like good designers do with their budget.

The best speaker designers will tell you that the only difference from their entry level models and their better ones are added extension at the bottom. Building a seamless QUALITY response in a single array from 20khz to 20hz is very expensive. Bass extension in particular is expensive to achieve. Cheaper speakers attempting it usually fail miserably everywhere - the "jack of all trades" syndrome, if you will. A good two-way design will sacrifice the bottom to cover the middle better. At the end of the day, most speaker systems are a controlled exercise in compromises.

Fact is, few people can reliably hear 20khz. And 20hz is more felt than heard. As I said before, when people hear "bass" they are hearing 100-250hz. What I always try to steer folks to is the midrange, where most of the music takes place. If on a budget, it is sometimes best to get a very capable bookshelf/monitor with a strong midrange (good treble is usually included, as it is relatively inexpensive). If more bass is needed, a subwoofer can then be considered. You'd be surprised that most are very happy without the latter.

You've already got an outboard subwoofer working the sub 100hz range. I'm still scratching my head over why you are using two more in your main speakers. The upper bass and mids are shortchanged as a result.

On top of everything else discussed, if these speakers are really that important to you, if you wish to invest more into them than they are worth (which is ok), might I suggest also upgrading/correcting the one element that is doing the most work, and which you haven't touched - the midrange.
 
Originally Posted By: Volvohead
Originally Posted By: OVERK1LL

The range for the woofers (subs) that I'm using is 25Hz - 2,800Hz if that helps?


There's NO WAY that driver is reaching 2.8khz in an effective sense. If that driver was still flat at 500hz, I'd be shocked. And it's not designed for those frequencies, either.

That may be its advertized absolute frequency range. But +/- 3db from nominal, which is how speakers are employed - NO WAY. Many tweeters are capable of emitting a 20hz signal, but at levels so far below their nominal that they are virtually inaudible. That's the roll off point of which I was referring above. And you don't want that driver working that far down, even if it could. The same applies to LF drivers.

What a crossover does is roll off the signal electronically, so the driver is not forced to reproduce frequencies that it is not designed for, and which adversely affects output at design frequencies. You don't want tweeters working bass, and you don't want woofers working treble. You certainly don't want a subwoofer working at 2.8khz . . . or even 280hz for that matter.

The original CV woofer I'm sure didn't extend as low, but was able to reach higher, to cover the Xover gap into the mids a little better. I suspect that the designer gave up a little on the bottom, like good designers do with their budget.

The best speaker designers will tell you that the only difference from their entry level models and their better ones are added extension at the bottom. Building a seamless QUALITY response in a single array from 20khz to 20hz is very expensive. Bass extension in particular is expensive to achieve. Cheaper speakers attempting it usually fail miserably everywhere - the "jack of all trades" syndrome, if you will. A good two-way design will sacrifice the bottom to cover the middle better. At the end of the day, most speaker systems are a controlled exercise in compromises.

Fact is, few people can reliably hear 20khz. And 20hz is more felt than heard. As I said before, when people hear "bass" they are hearing 100-250hz. What I always try to steer folks to is the midrange, where most of the music takes place. If on a budget, it is sometimes best to get a very capable bookshelf/monitor with a strong midrange (good treble is usually included, as it is relatively inexpensive). If more bass is needed, a subwoofer can then be considered. You'd be surprised that most are very happy without the latter.

You've already got an outboard subwoofer working the sub 100hz range. I'm still scratching my head over why you are using two more in your main speakers. The upper bass and mids are shortchanged as a result.

On top of everything else discussed, if these speakers are really that important to you, if you wish to invest more into them than they are worth (which is ok), might I suggest also upgrading/correcting the one element that is doing the most work, and which you haven't touched - the midrange.


If you have a suggestion for the midrange speaker, I'm all ears! (tee hee!)

Regarding the dedicated vs woofer subs, the dedicated is a sealed box 15" unit, and handles the REALLY low frequencies better than these 10" ones (in vented enclosures) do.

And yes, that range is the "absolute" range given by the manufacturer, but I was still surprised to see them list 2.8Khz as the ceiling
21.gif
 
A few points on your LS's:

1. You really don't have CV's anymore. Both woofer & tweeter are wildly different than OEM. The three cornerstones of any LS are: Cabinet, XO & drivers. All designed around each other. That harmony no longer exists.

2. The PS in your HK receiver reveals its weakness if you look at the power ratings between 8 and 4 Ohms. Plus the THD levels rise > 180%. That being said, you'll never use all that for more than a few mS, like when you drop a tone arm onto a record with the volume at max...

3. Don't confuse DC resistance with AC impedance! The latter is frequency dependant, the former isn't. Just because you wired both VC's in series to get 4 Ohms doesn't mean your HK will tolerate it. What you really need is a Z vs. freq plot (which might have some really wild swings in it).

4. Power isn't everything!

5. +1 on Volvospeeds comment #2647370 re: "Frankenspeaker".

6. If your cabinets are 75mm particleboard, no doubt they're pretty heavy. (Vented or Sealed?) You can make or buy spikes, just be sure you don't drill all the way though the cabinet when installing the t-inserts else you'll greatly affect the alignment (even though it's all wrong as it is...)

A quick, cheap, effective alternative is to pickup 8 of those triangular finger cushions that slide over pencils and enough pencils to equal 8x the length of one, without counting the erasers. Get real pencils too, with graphite 'leads'. Also make sure they fit snugly.

Measure the length of a cushion and cut a pencil to fit flush on both ends. Put one at each corner of your walking-cabinets. No more movement, nor damaged hardwood floors. Such a cheap thing works surprisingly well because of the materials used: gooey/gummy rubber/plastic, wood and graphite. Experiment with the orientation. Try a test with one cabinet 'treated' and the other original. Hear any difference? All depends.

7. Re: Spiked, mass-loaded stands. As a woodworker, I've used wooden tops & bottoms and Sch40 (thick-wall) PVC in large diameters to connect the two, filled with sand. I route a dado in top/bottom to accept the pipe dia and use a long threaded rod to keep the whole thing together once assembled.
Ideally, tweeters need to be at ear height when sitting. However, it's not always practical with a large cabinet. So you might want a stand about 30-60cm high.
You'll also need pvc 15-25cm in dia. The big stuff. I've had good luck finding scraps of this at construction sites. To cut it straight, wrap a sheet of long paper around the circumference, line up the ends and tape. Then draw your line. Cut carefully. Hopefully you know someone with a bandsaw. Attach a full sheet of sandpaper to something flat and use it to sand the edges smooth. Cut your dados with a router.
Large pvc gives you a round column, you can prime & paint any color you wish or you can easily veneer and you can hold a lot of sand as the area rises with the sqr of the radius. Thus my suggestion of large dia. which are appropriate given your situation.
As VolvoHead recommended, you can use his suggestion with this technique by bolting your cabinets to these heavy stands. Your car sub will now have A LOT more mass to move around. I'll leave you to work out the details.
This is the text-book definition of a high-mass stand with spikes. If you spike the base of these stands, with sand and your cabinets on top the psi on the tips of the spikes will be very high indeed.


Originally Posted By: OVERK1LL
The range for the woofers (subs) that I'm using is 25Hz - 2,800Hz if that helps?
That's a laughable spec! No -3dB down corners, no response plot, nothing. No offense, but it's laughable.

In summary, I'd try the triangle dampers. They're cheap, quick and effective. Second, it's a waste of $$$ to put $$$$ XO parts in a XO that isn't appropriate. Third, I'd encourage you to continue playing around with this, but with the caution that it's a mistake to put Prius tires on your M5 expecting true performance! If you want to read up on this, I'd suggest Speaker Building 201 by Ray Alden and The Loudspeaker Design Cookbook by Vance Dickason.
 
Originally Posted By: sleddriver

3. Don't confuse DC resistance with AC impedance! The latter is frequency dependant, the former isn't. Just because you wired both VC's in series to get 4 Ohms doesn't mean your HK will tolerate it. What you really need is a Z vs. freq plot (which might have some really wild swings in it).



They are wired for 8ohms, they are the DVC 4ohm version.





Quote:
That's a laughable spec! No -3dB down corners, no response plot, nothing. No offense, but it's laughable.


Well, perhaps you are more keen at deciphering the information they provide on their site than I.

http://www.bravoxaudio.com/pxw.asp

There's a .zip with the manual for them there. These are the PXW10D4's.

Quote:
In summary, I'd try the triangle dampers. They're cheap, quick and effective. Second, it's a waste of $$$ to put $$$$ XO parts in a XO that isn't appropriate. Third, I'd encourage you to continue playing around with this, but with the caution that it's a mistake to put Prius tires on your M5 expecting true performance! If you want to read up on this, I'd suggest Speaker Building 201 by Ray Alden and The Loudspeaker Design Cookbook by Vance Dickason.


WELL played sir
wink.gif


The latter publication is actually recommended in the manual for the speakers. Whether that means anything of significance to you or not?
21.gif
 
I just want to note here that it is quite obvious I'm not an audiophile of any sort and I hope I made that clear with my first post in this thread. If it wasn't, I'm sure my questions asked since then have made it so.

But I don't mind learning! And this is a lot of fun, I think the suggestions given are great
thumbsup2.gif


I'll play around with them when I have some time and certainly post back my results
smile.gif


-Chris
 
Originally Posted By: OVERK1LL
I just want to note here that it is quite obvious I'm not an audiophile of any sort and I hope I made that clear with my first post in this thread. If it wasn't, I'm sure my questions asked since then have made it so.

But I don't mind learning! And this is a lot of fun, I think the suggestions given are great
thumbsup2.gif


I'll play around with them when I have some time and certainly post back my results
smile.gif


-Chris


Who and what you are are your choices. You define yourself. There are no tests for admission to the hobby. Some have spent many years in it and yet know very little. Others not so much but are very sage indeed. Just like everything else in life. I don't consider myself an "audiophile", either. I just like great sounding music that is right THERE, when I want it.

Nobody's audio system is perfect, because there is no single formula for perfection. Just have fun with what you have and with what you want to put into it. If you think something sounds great, it sounds great. You're the only listener that needs to be satisfied.

Again, just enjoy yourself and have fun with it. Be open-minded (which you appear) and willing to share your experiences if possible. Sometimes the journey is more fun than the destination. Only if you stop having fun with it are you off the path.
 
Originally Posted By: SteveSRT8
And you CAN be an audiophile. Anyone can.

You obviously are passionate about your music. That's enough for membership.


Thanks Steve
smile.gif
I want to learn! I LOVE music (I play bass guitar as well) but I've never been much into the "science of sound" so to speak until very recently. So much of the terminology used in this thread is somewhat new to me.
 
Originally Posted By: OVERK1LL

They are wired for 8ohms, they are the DVC 4ohm version.
OK. Sometimes XO's have some rather wild swings in the impedance curve as the freqency varies. This drives some amps nuts. A Pro amp would be more tolerant of this. That's the short answer!

Quote:
In summary, I'd try the triangle dampers. They're cheap, quick and effective. Second, it's a waste of $$$ to put $$$$ XO parts in a XO that isn't appropriate. Third, I'd encourage you to continue playing around with this, but with the caution that it's a mistake to put Prius tires on your M5 expecting true performance! If you want to read up on this, I'd suggest Speaker Building 201 by Ray Alden and The Loudspeaker Design Cookbook by Vance Dickason.


Quote:
WELL played sir
wink.gif


The latter publication is actually recommended in the manual for the speakers. Whether that means anything of significance to you or not?
21.gif

I did note the mention of LDC when I looked at the driver specs. Not sure what you mean by "Whether that means anything of significance to you or not?" It is a great reference and well worth reading. That's why I included it in my post.
 
Originally Posted By: OVERK1LL
I just want to note here that it is quite obvious I'm not an audiophile of any sort and I hope I made that clear with my first post in this thread. If it wasn't, I'm sure my questions asked since then have made it so.

But I don't mind learning! And this is a lot of fun, I think the suggestions given are great
thumbsup2.gif


I'll play around with them when I have some time and certainly post back my results
smile.gif


-Chris


By all means, have fun experimenting!
 
Originally Posted By: sleddriver
Originally Posted By: OVERK1LL

They are wired for 8ohms, they are the DVC 4ohm version.
OK. Sometimes XO's have some rather wild swings in the impedance curve as the freqency varies. This drives some amps nuts. A Pro amp would be more tolerant of this. That's the short answer!

Quote:
In summary, I'd try the triangle dampers. They're cheap, quick and effective. Second, it's a waste of $$$ to put $$$$ XO parts in a XO that isn't appropriate. Third, I'd encourage you to continue playing around with this, but with the caution that it's a mistake to put Prius tires on your M5 expecting true performance! If you want to read up on this, I'd suggest Speaker Building 201 by Ray Alden and The Loudspeaker Design Cookbook by Vance Dickason.


Quote:
WELL played sir
wink.gif


The latter publication is actually recommended in the manual for the speakers. Whether that means anything of significance to you or not?
21.gif

I did note the mention of LDC when I looked at the driver specs. Not sure what you mean by "Whether that means anything of significance to you or not?" It is a great reference and well worth reading. That's why I included it in my post.


I meant about the fact the speaker company mentions that publication in their own documentation for these woofers, if that meant anything of significance to you RE: Bravox as a company.
 
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