Building the best loudspeakers

[ShinOBIWAN]

Originally posted by Ceibal



Ok, then is there a good dual woofer design that I could start with? I did not see one from some of the links people have posted or maybe I just missed it.

Dual woofer? Are you still talking about an MTM or some like a TMWW?

[Ceibal]

Is x over 3 pro any good? Has anyone used it?

[Ceibal]

Originally posted by ShinOBIWAN


Dual woofer? Are you still talking about an MTM or some like a TMWW?

still talking MTM

[Ceibal]

http://www.partsexpress.com/pe/showd...number=302-751


above is the box I am looking at from Parts Express.

[ttan98]

Originally posted by HiFiNutNut


The 18W8531G00 is highly recommended. It is obviously better than the 18W8545 I previously worked with. The T330D is no doubt much better than the Seas Millenium I used.

I am thinking of using 8545 and you say 8531 is better at the same time more expensive. It is better by big or small margin, and in what way it is better? Please explain.

[ScottG]

Originally posted by Ceibal
Is x over 3 pro any good? Has anyone used it?

..modeling without measurement capability (for actually building a loudspeaker), is of little worth.

The current favorite seems to be SoundEasy. It would of course also require numerous other things:

http://www.zaphaudio.com/setup.html



Anyway, doing without the design work..

This is your best bet in stand mounted MTM designs:

http://www.zaphaudio.com/BAMTM.html

As long as the baffle is the same exact dimensions then you should get a very similar upper freq. response.

This particular cabinet is the curved version of the 1 cubic foot pre-fab partsexpress box - with the same baffle dimensions.. so it should work for the sealed design without any problems.

[Ceibal]

Originally posted by ScottG



..modeling without measurement capability (for actually building a loudspeaker), is of little worth.

The current favorite seems to be SoundEasy. It would of course also require numerous other things:

http://www.zaphaudio.com/setup.html



Anyway, doing without the design work..

This is your best bet in stand mounted MTM designs:

http://www.zaphaudio.com/BAMTM.html

As long as the baffle is the same exact dimensions then you should get a very similar upper freq. response.

This particular cabinet is the curved version of the 1 cubic foot pre-fab partsexpress box - with the same baffle dimensions.. so it should work for the sealed design without any problems.

I really appreciate the help. I know some of these questions are stupid but I am just learning. I did buy Daytons woofer tester knowing I would need some way of testing the speakers once I got them. Will this work or did I just wast my money?

[ScottG]

Originally posted by Ceibal



I really appreciate the help. I know some of these questions are stupid but I am just learning. I did buy Daytons woofer tester knowing I would need some way of testing the speakers once I got them. Will this work or did I just wast my money?

Not a waste.. if you really get into this hobby, then a quick way of testing the driver's TS parameters, (not its impulse response derivatives like freq. response), can be very useful. Its also good just to check that those parameters are within spec. quickly - so you aren't using a damaged or poorly made driver.

If you aren't really into the hobby, then you can always sell it on the secondary market (..prob. less than half the purchase price though).

Again though, IF you aren't throughly committed to the hobby then SERIOUSLY consider a proven design. Again, Troels, Tony Gee, and yes even Zaph have some very good designs.

Note that the major reason I suggested the BAMTM from Zaph is that it "fits" with the MTM you wanted and in the enclosure you specified. It most certainly is NOT a design I'd recommend as a 5K speaker beater.. not that it couldn't, but rather when I think of such a design I tend to look for several outstanding features. The BAMTM doesn't have this - its just a really good stand mount with the one excellent feature of extended bass in a sealed enclosure of a very small size. (EDIT: Actually it has one other outstanding feature: price.) Now IF you are more particular about your crossover components and can measure the values to make sure they match what Zaph spec.s - then you might well be able to enhance the design, but that really depends on if YOU hear a difference between different components. Still though, its a good place to *start*.

My suggestion then really depends on your preference:

1. If you want to design your own loudspeaker and a willing to put in a lot of time, effort, and money - then start with learning how to use SoundEasy. Note that you don't even have to purchase the program to get a "taste" for this.. instead read and re-read the owner's online manual and/or first purchase JohnK's excellent primer on SoundEasy:

http://www.musicanddesign.com/Guide.html

http://www.interdomain.net.au/~bodzio/

2. If you want a design that fits within the MTM and cabinet selection you have made then stick with the BAMTM. After making it, then consider crossover parts upgrade (Goertz foil inductors, capacitors taken for value and performance from TonyGee's Capacitor test, and perhaps winding your own resistors - do a search for that on diyaudio). IMO though, your best bet here is to make use of an outboard crossover (i.e. do not stick the crossover in the cabinet (for a visual, look at the Wilson audio Duette).

i.e the box at the bottom of the stand:

http://www.wilsonaudio.com/images/du...less-Grill.jpg

3. If you want a design that does have several "wow" features, then consider something like:

http://www.humblehomemadehifi.com/Humble_Statement.html

http://www.troelsgravesen.dk/JA8008.htm

http://www.troelsgravesen.dk/AcapellaNEXT.htm

http://www.troelsgravesen.dk/AT-R.htm

Jim Griffin's JX92S designs

http://www.creativesound.ca/details.php?model=AlphaLS

4. If you want something thats different (and again has "wow" features), but can be more of a "turn-key" solution - then consider the LinkwitzLab Orion or JohnK's Nao.

5. If you want something that pushes the envelope of design then perhaps you should wait until Lynn Olsen finalizes his next design (..though it could be a substantial wait).

With the exception of the JA8008, all will be costly - but all should give you "state of the art" in several respects, (though note that several have significant limitations particularly with respect to low freq. extension and power handling). Hey, its all given-and-take.

Note though that there are LOTS of other solutions as well.. for instance you could skip a lot of the complexity surrounding crossovers by using an active digital crossover (and more amplifiers). (..and of course there are compromises there as well.)

Best thing is to research it, give it a lot more thought - and then make a decision. The one thing I would counsel you on is that IF you aren't into wood working, and you DO want to pursue the hobby, then strongly consider finding some one who does that professionally near you - and paying them to do what you might not be able to.

One final "word" of advice:

If all of this puts you off, (which it certainly wasn't intended to), then seriously consider this:

A reason NOT to DIY..

[planet10]

Originally posted by ScottG
.. for instance you could skip a lot of the complexity surrounding crossovers by using an active digital crossover (and more amplifiers). (..and of course there are compromises there as well.)

You could also just skip the crossover and go with a 1-way.

dave

[rabbitz]

Originally posted by HiFiNutNut
Rabbitz,

The 8531 is planned to be used as a mid and upper base to cover 150Hz to 2000Hz. Below that I have the 8561. I have not built the active XO yet so the 8531 is being run from 20Hz-2000Hz without EQ in an OB stuffed U-frame, with a simulated XO to cross over to the tweeter, in MTM. This arrangement is for running-in the drivers only before taking acoustic measurement.

It sounds very good indeed. Distortion arises when playing loud bass materials but that will be gone once the 8561 comes into the picture. It is not 100% accurate as I can hear the dipole peak making the music a bit chesty but overall gives a very satisfactory sound. I can imagine how good the system sounds when completed.

I am totally happy with the 8531 used as mid or bass driver. Its bass quality is very surprising (good).

By the way, with the drivers and cabinets I have, in theory the XO point should be at 2kHz (1 wavelength between the tweeter and midrange) and should not be higher. However, I have modelled some gentler asymetrical slops for the two drivers and I believe the XO would sound excellent but with a XO point at 2.6kHz. That is too high in theory. I am not sure if I will try that.

Do you use MTM? how does your 8531 sound with 2.4kHz XO? at what slop?

Regards,
Bill

Thanks for the reply Bill.

I just run the single driver in partnership with the S2905 and M22WR and find the sound exceptional with great inner detail and natural tonal quality..... a lot due to the OB. The driver is still however acoustically loaded with some damping material. Power handling is not a problem even with the rated 60W so 1 driver is enough. I'm not huge on the volume control but do like a decent SPL.

Checked my info and the xo is just under 2600Hz (not 2400Hz... sorry my mistake) and 2nd order acoustic slopes with a tad less on the woofer. I did try some low xo points down to 1800Hz and higher orders on the tweeter but didn't sound as good for me.... tended to suck out some of the life. In theory, I'm running them too high but in real life it sounds better for my tastes.

I'm surprised at the amount of bass the 8531 was producing in the OB and is aided by a series resistor which brings the mid level down a tad but helps the bottom end. The odd bass I was referring to was in a vented enclosure and could never get it right but in OB, don't need it as the M22WR does the job. I did try a 22W8851T00 but was bettered by the M22WR in this instance but would have been better with steeper slopes but still not as good IMO. The M22WR is a freak and better than it has a right to be.

Sounds like yours is going to be a cracker. Good luck with it.