Large floorstanding, "Project 110db"

[cujet]

JonMarsh,

I found the M12 at the following site http://estore.websitepros.com/1736754/Detail.bok?no=312
For $105.00. That seems like a good deal, and that price got me thinking.

Also, your suggested tweeters, do they sound nice like a good dome? I have, and have had, a few sets of compression tweeters and they are too harsh for my taste (they remain in the attic). I have all sorts of speaker components at home from past projects. I suppose that is why I have these "Preconceived Notions". I am willing to adjust my thinking when trusted people steer me in the correct direction. After reading your writeup on the M12, I would be willing to go ported to achieve a 23HZ -3db.

cjd, I think a 4 way would be way cool if I could figure out all the issues with the crossover. With the proper help I might be able to do it. However, I have not heard many 4 ways that I liked. I suppose it gets complex (even for the pro's). That is why I was thinking about ribbon tweeters.

Once again, thanks for the suggestions. It sure is fun figuring this stuff out.

Chris

[cjd]

Ribbon still leaves you short in the midrange (or really stretched) since most don't really start to do so well till ~3kHz. Unless you've got a little cash to spend. Find mids that cover that high well and they lose out on sensitivity/max SPL or they mean you have to push the bottom up, which means you're now crunched for woofer size... or you go 4-way again.

4-way would be expensive - three times the complexity of a 2-way...

[JonMarsh]

JonMarsh,

I found the M12 at the following site http://estore.websitepros.com/1736754/Detail.bok?no=312
For $105.00. That seems like a good deal, and that price got me thinking.

Also, your suggested tweeters, do they sound nice like a good dome? I have, and have had, a few sets of compression tweeters and they are too harsh for my taste (they remain in the attic). I have all sorts of speaker components at home from past projects. I suppose that is why I have these "Preconceived Notions". I am willing to adjust my thinking when trusted people steer me in the correct direction. After reading your writeup on the M12, I would be willing to go ported to achieve a 23HZ -3db.

cjd, I think a 4 way would be way cool if I could figure out all the issues with the crossover. With the proper help I might be able to do it. However, I have not heard many 4 ways that I liked. I suppose it gets complex (even for the pro's). That is why I was thinking about ribbon tweeters.

Once again, thanks for the suggestions. It sure is fun figuring this stuff out.

Chris

Most compression drivers are pretty terrible, due to a combination of energy storage, irregular frequency response, and issues with the throat and expansion design of the horns.

As an example of how good a "conventional" horn can sound, I'd reference you to the TAD drivers as well as complete speakers like the JBL K2-S9800.

This particular BMS driver (made in Germany) is rather small and compact, extended frequency response, and low distortion. It's been discussed in some other threads on this and other forums, and it's sourced from BMS by JBL with JBL's own part number.

The other aspect is waveguide design- and I use that term rather deliberately. For a good discussion on waveguides, check out Dr. Geddes books on the topic- available from Gedlee. The big thrust in modern "waveguide/horn" development has been the reduction of throat expansion discontinuities and High Order Modes (reflections) which ocurr as a result of this.

I'm familiar with a lot of conventional direct radiator tweeters, having purchased and tested many of the more expensive SEAS, Scanspeak, and Accuton models. This combination is very comparable in sound, except that it is absolutely effortless at 100 dB levels and higher. Note that this waveguide has very good pattern control- that is, the level falls a bit as you go further off axis, but in a wide operating range the frequency response below 15 kHz does not change- this means that very consistent power response is possible, better than any direct radiator tweeter (look at their off axis plots at 30 degrees).

Just something to think about- when someone comes on boards and raises some lofty goals, we like to respond in kind.

And that is a good price on the M12, will have to keep that in mind if I want to play with them someday. Another thing I like about the Aurasound is the Neo motor and lower weight.

You're not aware, but I have done several designs with the HiVi M8a driver, and I like the inverted done cone structure and it's rigidity a lot.

~Jon

[cujet]

Question, if the Aura is capable of 110db at 50HZ, couple that with room gain, a stereo setup with both sides playing and proper placement have I met my goal with only 1 woofer per side?

If so, at what power level?

Chris

[Scottg]

Question, if the Aura is capable of 110db at 50HZ, couple that with room gain, a stereo setup with both sides playing and proper placement have I met my goal with only 1 woofer per side?

If so, at what power level?

Chris

If you look closely at the bottom Jon says this:


"But you need two if you really want 110 dB or more."

Note that I doubt BSC is considered either - so while you have room and possibly boundary gain, you will also suffer about a -7 to -8 db loss.

Furthermore - the modeling he has done is with a BASS REFLEX design (..not that there is anything particularly wrong with that - just that it IS different than a sealed design and typically exhibits less "punch" than a sealed design.) While I like the design, my thought is that it is *not* primarily what you are looking for. Again, sacrifice low freq. EXTENSION to get what you want (high spl's and high force).

What I find odd is that the driver is spec'ed at a MUCH lower efficiency than what Jon has measured.. (or likely I'm misinterpreting Jon's graphs and comments.) :scratchhead:

Another (and less costly) alternative to the 2 ciare's I mentioned at DIYAudio are a pair of Eminence BP102's per side in a sealed enclosure - BUT high output won't be as great, AND you'll need about 40 liters per driver. (..note that bass guitar people consistently praise this driver for its "punch" quality :T .)

[Jed]

I'd like to see an WWMTMW with dual Aurasound 12 or 10" drivers in series, SEAS ER18RNX, dual RS52 in series, and maybe RS28 or SEAS tweeter in an all out Duntech style enclosure via Duelund style crossover 4 way. That should get you to 110DB.

[Jed]

If
What I find odd is that the driver is spec'ed at a MUCH lower efficiency than what Jon has measured.. (or likely I'm misinterpreting Jon's graphs and comments.) :scratchhead:

:T .)

Jon spec'd it at 2.83V versus 1watt listed by Aurasound. I think that explains the differences.

[Scottg]

Jon spec'd it at 2.83V versus 1watt listed by Aurasound. I think that explains the differences.

I see it now (it was to show differences between it and the HiVi - i.e. at a 2watt input). It does however still seem a bit high - even with a 1 kHz test (perhaps a better driver?)

I look at it inverted (like Aurasound does) i.e. one watt at one meter - guess I'm a "glass is half empty" sort of person.. :B

[Scottg]

I went looking through pricing on the BP102 - almost everyone is 75 per driver. Parts Express however is lower (about 72.50 each or for 4 about 70.50 through email) - then you go over to another supplier that does price matching, AND free shipping! Perhaps even add-in "same day shipping" as well. (..though you always need to make sure they have them in stock for your order.)

All-in-all - about 141 US (per loudspeaker), is a pretty low cost solution. :T

Better yet, it appears that PE is also offering free shipping on orders +99 Us from 7/20/07 to 9/19/07.

[cujet]

Scottg,

You really think the BP102 will sound good? Every pro speaker I have heard in home audio sounds like crap. Is there something I am missing with current pro audio stuff? I would be willing to try this if I was sure the quality of the sound would agree with me.

There is a small local store that has all sorts of pro drivers along with a few HiFi home speakers. There is no comparison, but to be fair, I stopped listening right away. There were even some set up for home use.

Chris

[Dennis H]

Is there something I am missing with current pro audio stuff?

Yes.

[Scottg]

Scottg,

You really think the BP102 will sound good? Every pro speaker I have heard in home audio sounds like crap. Is there something I am missing with current pro audio stuff? I would be willing to try this if I was sure the quality of the sound would agree with me.

There is a small local store that has all sorts of pro drivers along with a few HiFi home speakers. There is no comparison, but to be fair, I stopped listening right away. There were even some set up for home use.

Chris

I *very* much do think it will sound good - if used properly.

Consider that a lot of pro gear sounds like crap simply because it is NOT used properly. Enclosure volumes that are to small for the driver's param's. Poorly constructed enclosures. Occasionally trying to achieve bass extension with a poorly chosen venting freq. (for those designs using bass reflex). And perhaps the worst problem - running drivers full range (or near full range) and crossing over to a REALLY cheap piece of crap.

The sad fact is that most of the lesser pro gear (..and thats most of the stuff you would come across), is not designed for anything like linearity - even their so called "monitors".

So while I can't guarantee that you'll get exactly the sound you are looking for - I am *pretty sure* though that IF you use it from about 300 Hz down with about 40 liters per driver (2 per loudspeaker connected in paralell), AND use a crossover with suitable eq. maximising linearity in-room and with your other drivers, THEN (and only then) you will near (and perhaps surpass) your expectations (..minus near average spl's at freq.s below 50 Hz or so depending on how much you effectively pad down the response with eq.). (..note though that the driver will need some "running in" to loosen up its suspension.)

If it isn't obvious - I'm stressing that you really need to learn how to *DESIGN* a loudspeaker. (..or you need to get help with this.)

Finally, here is a customer comment on the driver's subjective qualities in (mostly) the passband you would use it for:

http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=290-471&vReviewShow=1&vReviewRand=7076867#reviews

Good luck!

[cujet]

I'd like to see an WWMTMW with dual Aurasound 12 or 10" drivers in series, SEAS ER18RNX, dual RS52 in series, and maybe RS28 or SEAS tweeter in an all out Duntech style enclosure via Duelund style crossover 4 way. That should get you to 110DB.

OK, I am considering this theme, I like it! But, why a single SEAS?

Jon, dual Aura 12's wired in series would be how efficient???? Or are you suggesting a 2 ohm setup.

Scottg said "If it isn't obvious - I'm stressing that you really need to learn how to *DESIGN* a loudspeaker." I am learning, every day. I have been building DIY speakers for 30 years. But this is not my field of expertise and I do not do it often.

Chris

[Jed]

Ok, WWWWMTMW or WWMTMWW with dual seas, dual aurasound subs, dual RS52, and ??? tweeter- maybe a H1212 so you can cut the flange to get closer center to center spacing.

[dblotii]

What about the Magna cum laude's?

Can anyone offer a review of the Magna Cum laude's?

Dave

[cjd]

On the MCL's - if serious listening is your thing, they're not gonna cut it. If cranking it up for a party where music isn't the focus, they're not bad. Nothing special though. I believe that's how they're officially billed too.

C

[whoaru99]

I've read this thing and it almost seems there is a hang-up between low end extension and "punch". Isn't the "punch" a bit higher up the scale from the low end extension?

The speakers here are not of the type generally discussed on this forum. But, if high output and "punch" are the desired goal, perhaps something there is worthy of consideration.

[cujet]

I've read this thing and it almost seems there is a hang-up between low end extension and "punch". Isn't the "punch" a bit higher up the scale from the low end extension?

Well, as I mentioned, I am not a speaker building pro. From what I have heard, most speakers that extend low are soft or muddy sounding in the upper bass.

I might as well admit that I want my home stereo to have the punch of my truck stereo.

Chris

[Brian Bunge]

I might as well admit that I want my home stereo to have the punch of my truck stereo.

Sounds like you are going to need much more power and lots more woofers! :twisted:

[Dennis H]

Yeah, Brian's got that right. As mentioned in this thread, punch is related to the ratio of driver swept volume to room volume. Let's say your truck has a volume of 100 cu.ft. and your room has a volume of 2000 cu.ft. Want the same punch in your room as in your truck? No problem, just use 20x the woofers and amps.

[whoaru99]

Sounds like you are going to need much more power and lots more woofers! :twisted:

Or, speakers with high sensitivity to cut down that power requirement...

A couple weeks ago I picked up some Yamaha Club Series PA speakers. They don't go very deep, and their not audiophile grade sound (but more than adequate when you need that loud rock fix), but PLENTY of punch/slam from those 4 x 15" @ 99dB sensitivity driving with only ~70wpc.

[---k---]

But wouldn't you need ungodly loud spl to get there? I mean, simplifying things, if you can get 105db with a single 8" driver, adding a second driver and playing the same 105db will decrease the required movement of both drivers and you end up with the same amount of air moved. To get enough air movement to feel it in a large room, don't you just have to turn it up ungodly loud? Am I missing something?