[chrisby]

I don't feel like you're diverting the thread.  Your comments are central to the design concerns I have for this system. 

I need to add that offline information I got from Dave (planet10) and TerryO were very important to the box design.  Danny from GR gave me the idea for the cap (which made a world of difference).  They saved me weeks of tweaking.

all in the spirit of community to which these forums aspire

congrats on the success with the project


and then ..... 

[BPoletti]

and then...   ???

Tune the room.  Starting tomorrow.  Or Friday, maybe.  Or next week...  It's nice to be retired.      

[TerryO]

Jeez Bill,

I just looked at the pictures and your "test mules" look nicer than any speaker I ever built...OK, I'm just kidding, as all of mine have been monuments of exquisite beauty.
 
 
I'm surprised that you've moved so quickly in getting these built, but then, you've never let any grass grow under your feet.
 
One thing that needs clarification, is that Bill has been overly generous in giving me credit in regard to this project. Bill is quite knowledgeable himself (an old "Bass List" guy), as is Dave Dlugos (another "Bass Lister" from the old days).
 
I certainly look forward to watching this project progress.
 
Best Regards,
TerryO

[youravhandyman]

I won't pretend to be an expert on this topic but I thing you guys should see what "Hebrew Hammer" has created.  He has expanded on the idea that separate low frequency drivers is the way to go by bi-amping using a programmable electronic crossover.  And the speaker itself is a work of art.  You can see them on this thread:  http://www.audiocircle.com/index.php?topic=88014.0

or check out his website www.soundsbydesign.net

I'm a nube but totally impressed.  A couple of weeks ago I was lucky enough to hear these beauties.  They completely disappear.  Quite a feat in my book.

Matt

[TerryO]

I won't pretend to be an expert on this topic but I thing you guys should see what "Hebrew Hammer" has created.  He has expanded on the idea that separate low frequency drivers is the way to go by bi-amping using a programmable electronic crossover.  And the speaker itself is a work of art.  You can see them on this thread:  http://www.audiocircle.com/index.php?topic=88014.0

or check out his website www.soundsbydesign.net

I'm a nube but totally impressed.  A couple of weeks ago I was lucky enough to hear these beauties.  They completely disappear.  Quite a feat in my book.

Matt

Hi Matt,
As a matter of fact, I have seen several of his speakers and the idea is quite good, but hardly original, as many of us have been doing the same for quite a few years. If I had the time and ability I would post a picture of my arrays which, among other things, uses this concept. As far as a programmable crossover is concerned, I'm sure that Mr. Poletti would be quite at home with that, given the number of patents that he holds.

Best Regards,
TerryO

Just the same, his work is very nice and it wouldn't surprise me that they sound just wonderful.

[planet10]

I thing you guys should see what "Hebrew Hammer" has created.

IMHO, one ugly speaker, but there will always be wildy different opinions on art.

dave

[BPoletti]

IMHO, one ugly speaker, but there will always be wildy different opinions on art.

dave

I agree.  Butt-ugly and no hope for improvement.  Like looking at the wrong side of a blond hippo up too close.  At least they sound OK. 

[TerryO]

I agree.  Butt-ugly and no hope for improvement.  Like looking at the wrong side of a blond hippo up too close.  At least they sound OK.

The blond hippo?
 

Best Regards,
TerryO

[BPoletti]

The blond hippo?
 

Best Regards,
TerryO

When was the last time you were in Walmart?  (     ) 

[TerryO]

When was the last time you were in Walmart?  (     )

 

[chrisby]

When was the last time you were in Walmart?  (     )

or the sample testing line up at Costco?

even with 10ft wide aisles between racking, it's often a tight squeeze to get by


there's no denying the work involved in the soundbydesign stuff, and Terry would certainly approve of the liberal use of MDF and bondo -  although unfortunately covered with high quality paint job

"beauty" of course is in the mind of the beholder, and the fact that some of us remain married to the same / only spouse after over 30yrs,  there's proof of least 2 other cliches 

[TerryO]

or the sample testing line up at Costco?

even with 10ft wide aisles between racking, it's often a tight squeeze to get by

Now that I think about it...Naw, I'd rather not!

there's no denying the work involved in the soundbydesign stuff, and Terry would certainly approve of the liberal use of MDF and bondo -  although unfortunately covered with high quality paint job

Please Chris, I prefer the use-specific term: "Activated Polyester Tone Sauce". Bondo just sounds so......Walmart.   

"beauty" of course is in the mind of the beholder, and the fact that some of us remain married to the same / only spouse after over 30yrs,  there's proof of least 2 other cliches 

It's next summer for "Evil Annie" and henpecked TerryO.
 

Best Regards,
TerryO

[BPoletti]

OK, back on thread....  (but it was so much fun getting off-topic!)

Did the first really serious listening this evening.  The sound is very smooth, detailed and transparent.  I added in a couple of subs (note: not crossed-in, but added) running off of an old Marchand x-over used as a low-pass @ ~ 60Hz 4th order.  Yeah, they will work just fine.  Also, ran the FR125SRs a little too hard.  They repaid the favor with some awful sounds.  Not sure they bottomed-out, but they definitely modulated the highs and were very distorted.  Yeah, the subs are going to help a LOT. 

Played mostly some really excellent vinyl a friend brought over as well as some of my own.  Vocals, wind band (Mercury Fredrick Fennel), full orchestra, solo classical guitar and a couple of Rodrigo guitar concertos (Mercury The Romeros).  Even some London Pinafore. 

Our shared conclusion was that the drivers were good enough to use in a system, and that they DEFINITELY needed a couple of subs crossed-in (take the lows off of the FRs).  There is also a basic box design problem.  We were both hearing imaging problems, particularly with percussion, at the extreme left and right edges when the instruments position was near the speaker.  The instruments jumped to the cone of the driver.  We thought it was likely the wide baffle.

So.......  (any comments on the following?)

Away with those ugly boxes, now nicknamed the blond hippos.  And on to the next test design.  A narrow baffle, maybe 6" - 6 1/2" wide, beveled or rounded to just short of the width of the speaker.  Speaker mounted as close to the top edge as reasonable.  Bipole to help compensate for baffle step loss (adjust cap size across rear-firing driver until reaching the correct).  20 litres sealed (works good / smooth in the current box).  Need to work out some kind of base to keep them from falling.   

A little time in front of SketchIt should do the trick. 

[BPoletti]

It's next summer for "Evil Annie" and henpecked TerryO.
 

Best Regards,
TerryO

Uhhh...  Terry, your wife doesn't follow threads on this forum does she?   

 

[TerryO]

Uhhh...  Terry, your wife doesn't follow threads on this forum does she?   

 

Bill,
How on Earth did you guess? 

[TerryO]

OK, back on thread....  (but it was so much fun getting off-topic!)

Did the first really serious listening this evening.  The sound is very smooth, detailed and transparent.  I added in a couple of subs (note: not crossed-in, but added) running off of an old Marchand x-over used as a low-pass @ ~ 60Hz 4th order.  Yeah, they will work just fine.  Also, ran the FR125SRs a little too hard.  They repaid the favor with some awful sounds.  Not sure they bottomed-out, but they definitely modulated the highs and were very distorted.  Yeah, the subs are going to help a LOT. 

Played mostly some really excellent vinyl a friend brought over as well as some of my own.  Vocals, wind band (Mercury Fredrick Fennel), full orchestra, solo classical guitar and a couple of Rodrigo guitar concertos (Mercury The Romeros).  Even some London Pinafore. 

Our shared conclusion was that the drivers were good enough to use in a system, and that they DEFINITELY needed a couple of subs crossed-in (take the lows off of the FRs).  There is also a basic box design problem.  We were both hearing imaging problems, particularly with percussion, at the extreme left and right edges when the instruments position was near the speaker.  The instruments jumped to the cone of the driver.  We thought it was likely the wide baffle.

So.......  (any comments on the following?)

Away with those ugly boxes, now nicknamed the blond hippos.  And on to the next test design.  A narrow baffle, maybe 6" - 6 1/2" wide, beveled or rounded to just short of the width of the speaker.  Speaker mounted as close to the top edge as reasonable.  Bipole to help compensate for baffle step loss (adjust cap size across rear-firing driver until reaching the correct).  20 litres sealed (works good / smooth in the current box).  Need to work out some kind of base to keep them from falling.   

A little time in front of SketchIt should do the trick.

Bill,

Have you tried a hi-pass on the 125's and turned on the juice? That would give you an idea of what their behavior will be. If the Marchand is 4th order you may want to center the crossover at 100-125 Hz just to give a semblance of reality and then adjust it up or down to where you think it's getting a bit out of hand. Just an idea to while away the time, but it may indicate if your drivers want to live in that neighborhood.

If you're using Sketch-up, can you design a elliptical (as seen from the top) cabinet for the 125's?
It may help to cut down on edge diffraction as it transitions from 2 Pi to 4 Pi and perhaps aid the lateral imaging a bit (perhaps even with the narrow ends truncated). At this point I'm merely speculating and it may turn out to be a real bad idea...which, of course, would be the first time that ever happened.


Best Regards,
Terry

[BPoletti]

I can sorta draw an elliptical cabinet, but I don't have the skills to build it.  I do have a table router, a stand alone router and a plunge router at my disposal, also a bench saw with a blade that can be adjusted to create a nice bevel. 

I haven't tried just throwing a cap in series with the FR125SRs.  I also don't intend to use the Marchand but have that option if the SB12s just suck when they start to get into the midrange.  I have to measure again. 

Also have to step back at the end of next week for a little while.  Then get going again at the end of March. 

[planet10]

Please Chris, I prefer the use-specific term: "Activated Polyester Tone Sauce". Bondo just sounds so......Walmart.

We gonna see some fresh APTS at this year's diyFEST?

[planet10]

Not sure they bottomed-out, but they definitely modulated the highs and were very distorted.

You would know. There is little warning and a very disturbibg fart when they hit the limits. Worst with SE amps (any siz, tube or SS).

dave

[planet10]

So.......  (any comments on the following?)

Picture from the white paper > http://www.grimmaudio.com/news.htm

dave