Is there interest in a large three way "monkey coffin" collaboration?

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

I've been modelling around 100 liters but smaller would be OK. I'm figuring 42" tall and 15" wide external with depth as needed. That is more tower than Monkey Coffin I guess but I don't see the point of building a 30" tall "floorstander". What do others think about the form factor esp the height.

I think your dollar amounts are right what I had in mind. Agreed that "music speakers" that are full range for music but won't do a JoeyButts HT experience is right on the money. I think it should be fun and affordable.

Most tweeters will "keep-up" with all but the most sensitive woofers with BSC and XO losses figured in. 4 cu. ft. is getting pretty big. That's the size of the "medium" mini-fridges or a keg-cooler (inside). Tossing some rough prices; $100-12" woofer; $45-mid; $30-tweeter, so $350 for drivers for a pair. $75 each for XO parts and misc. doable? I know I'm shooting a little high on drivers (safe).
Mayhem's room gain point is valid too. The lower you go, to about 23Hz or so, the more room gain I get in my living room. If an F3 of ~32 Hz helps the entire project $50-100 worth, which it might, it should be considered.
I think we need to focus on these being "music" speakers, and for home theater, they'll be "large front mains". You still will need a sub if you want the real HT experience. The advantage I see to these is you get an octave lower than most 14-16 liter 6 1/2-7" MT's for way less than a sub and the bookshelf monitors.

[djg]

Re: Is there interest in a large three way "monkey coffin" collaboration?

I've already built a pair of Econowaves in old Pioneer monkey coffin cabs. They sit in the basement unused, just don't need them. I do not need any more speakers and I doubt I will build these, as I am currently laid off.

But, since you asked, my preference would be for a short "proper monkey coffin" with variable L pads for the mid and tweet, like in the old days. They could be put on short stands, even tilted back a bit to get the correct modern ear level tweeter signal. Troels has a Seas 3 way classic design. I won't link it because it's not really like this project, with an 8" woofer, but it is somewhat old style with a compact cab, and looks very nice on a short tilted stand.

You could always make it bigger if you want.

[andy19191]

Re: Is there interest in a large three way "monkey coffin" collaboration?

What do others think? Personally I'd pick 89 db and able to solidly to down close to 20 hz than 92 db and able to go only to 35hz.

This is a choice: a speaker with serious quality bass using a big subwoofer in a big sealed box but with a modest efficiency or a speaker with modest bass extension to 35 Hz and using a port to get there but with higher efficiency and higher SPL. Different types of speaker. If you want the former then I would suggest defining it as the objective. Some have chipped in on the side of deep bass and some have chipped in on the side of efficiency. You are going to lose some interest whichever way you go.

Also as I am not a crossover designer, how much sensitivity do we need from the mid if we have a 92db woofer, a 15" wide baffle and want something approaching full BSC?

It depends on the overlap of the woofer/mid crossover and the transition to omnidirectional radiation. I think someone posted an example earlier in the thread. Once a woofer and mid have been pencilled in I am sure one or two will simulate it and make suggestions.

Andy, where at in Europe are you?

At the moment I am in the UK.

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

I don't need to build these either and assuming I do, I will probably end up giving them to family or friends.

I think the real monkey coffin vs tower style cab does have some appeal. I figure just to fit drivers we are looking at 30" minimum height. For a shorter box it just means a smaller volume available or a deeper enclosure. Reasonable tradeoffs to consider.

Sorry to hear about your employment situation. I hope it improves soon and your input is appreciated regardless of any plans to build this or not.

I've already built a pair of Econowaves in old Pioneer monkey coffin cabs. They sit in the basement unused, just don't need them. I do not need any more speakers and I doubt I will build these, as I am currently laid off.

But, since you asked, my preference would be for a short "proper monkey coffin" with variable L pads for the mid and tweet, like in the old days. They could be put on short stands, even tilted back a bit to get the correct modern ear level tweeter signal. Troels has a Seas 3 way classic design. I won't link it because it's not really like this project, with an 8" woofer, but it is somewhat old style with a compact cab, and looks very nice on a short tilted stand.

You could always make it bigger if you want.

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

I would choose the latter personally and since I have initiated this idea it is I guess my choice in the end but I am still waiting to see if there are lots that have other opinions. I think again that the ST-305 gives a nice balance of LF extension, output capability and efficiency at an affordable price. Once again thanks for pointing in that direction.

My simplistic understanding is that the transition to omni will occur around 300 hz for a 15" baffle width but I could be wrong. I think having a mid with some extra sensitivity that gets padded down is obviously a better situation than having one that just doesn't have enough sensitivity...no real solution for that kind of problem.

This is a choice: a speaker with serious quality bass using a big subwoofer in a big sealed box but with a modest efficiency or a speaker with modest bass extension to 35 Hz and using a port to get there but with higher efficiency and higher SPL. Different types of speaker. If you want the former then I would suggest defining it as the objective. Some have chipped in on the side of deep bass and some have chipped in on the side of efficiency. You are going to lose some interest whichever way you go.


It depends on the overlap of the woofer/mid crossover and the transition to omnidirectional radiation. I think someone posted an example earlier in the thread. Once a woofer and mid have been pencilled in I am sure one or two will simulate it and make suggestions.


At the moment I am in the UK.

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

Thanks Joey. Perhaps I'll find a time that works for you to come by and check them out.

I do. I have yet to play with eq'ing them, but I will tell you that sensitivity and power handling won't be an issue with them. I'll play around with them a bit today to really give you a personal critique.

[thekorvers]

Re: Is there interest in a large three way "monkey coffin" collaboration?

I think the Series II woofer I posted the alignment for above matches your idea of a compromise that is a better 12" woofer in a ported box.

I am all in on the ST305.

Who agrees?

+1

I have used it's larger sibling (ST385) and like it. I consider this series of woofers high value drivers.

[thekorvers]

Re: Is there interest in a large three way "monkey coffin" collaboration?

In light of Andy's tweeter observations here are a couple possibilities

http://www.madisoundspeakerstore.com/sb-acoustics-soft-dome-tweeters/sb-acoustics-sb26stcn-c000-4-tweeter-4-ohms/

This is SB is 4 ohm and costs a fair bit but will have plenty of sensitivity, plenty of power handling and is extremely well regarded lately.

http://www.madisoundspeakerstore.com/seas-soft-dome-tweeters/seas-prestige-h1280-06-22tff-tweeter/

This Seas is 6 ohm and also stretches the budget but should have sensitivity that is in the ballpark and does handle plenty of power.

http://www.madisoundspeakerstore.com/scanspeak-soft-dome-tweeters/scanspeak-discovery-d2606/9200-1-textile-dome-tweeter/

This Scan Disco is also 6 ohm and has probably adequate sensitivity and power handling. Still at the top of the budget.

http://www.parts-express.com/vifa-xt25bg60-04-1-shielded-dual-ring-radiator-tweeter--264-1012

This Vifa would probably fill the bill as well.

What other tweeters might work here on a budget of say $40 max per tweeter?

All valid choices. Don't overlook this one:

http://www.parts-express.com/vifa-dx25tg09-04-1-fabric-dome-tweeter--264-1020

[Squidspeak]

Re: Is there interest in a large three way "monkey coffin" collaboration?

+1

I have used it's larger sibling (ST385) and like it. I consider this series of woofers high value drivers.

I am also a fan of the Series 2 woofers.I used the 10'' ST255-8 for use
in an outdoor sub (sealed),100W dayton plate amp.I built 4 units for family, friends and
my own yard and they have been outstanding for 7yrs. of seasonal use. High power handling
good sensitivity and made in the USA for us patriots,also goes on sale quite regularly.

[djg]

Re: Is there interest in a large three way "monkey coffin" collaboration?

One other thought. If all parts are available at PE, it might become a featured project in a sales brochure.

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

I had thought of that possibility. I think for woofers, PE/Dayton is really almost the only viable player in this high value but reasonably high quality genre. For mids this is somewhat less true. For the tweeter, the advantage for this project probably tilts a little away from Dayton offerings but some of the other lines PE sells (esp Vifa) would offer several excellent options for this project.

There is no reason it couldn't be all from PE supplied parts and I think it would be cool if it was. I don't look around at other suppliers and see a woofer, mid or tweeter that we would look at and say that given the budget constraints and design goals would be dramatically better than an option sold by PE.

One other thought. If all parts are available at PE, it might become a featured project in a sales brochure.

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

Excellent suggestion. There may be no reason to look further. And the slight top ocave dip that it has in its native response may be a desirable voicing feature for this project....

All valid choices. Don't overlook this one:

http://www.parts-express.com/vifa-dx...eter--264-1020

[Mayhem13]

Re: Is there interest in a large three way "monkey coffin" collaboration?

.

So the DC380 in 4 cubic feet would give a Q in the .6 range? I modeled it in 100 liters with walls covered (not stuffed) and it did a Q of .71 or so and had an F3 of 41 hz or something. It would work great from perspective of the response shape. I think it's main limiting factor is the limited xmax. 4mm is pretty meager and the output at 30 hz won't crack 100 db. Perhaps that is loud enough though. The drooping response would make crossover easy. I just wish it had a little more Xmax.

????

Unibox has always been my goto modeling program and been accurate to measured outdoor response but YMMV. Here's my excursion plot at 20w......no where near xmax and 100db at 30hz for a single drive unit. Add a pair and room gain and it's enough to chase anyone out of a room.

Now ive always been practical where space is concerned and never really understood the whole stand mounted thing. In essence, we're taking up the same footprint wether a stand or enclosure so why waste the space and volume?.......just me of course.

There's always been the whoop a$$ factor of a 15" woofer over a 12 in my experience. They just do bass better to my ears. From a size standpoint, a 12" driver is certainly more practical........but a monkey coffin by definition isn't practical either so why dance around with it! lol Go for broke. If there was enough in the budget, i'd suggest TWO 15's per side. BAM!

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

I double checked a couple times but will look again. Perhaps I have a parameter entered wrong. I always used unibox previously but have started using Jeff B's WBCD because of the filter section it includes. My understanding is that they should match exactly because Jeff used unibox as the basis for his. When I get home I'll post my FR and excursion plots and model conditions just to help sort it out.

????

Unibox has always been my goto modeling program and been accurate to measured outdoor response but YMMV. Here's my excursion plot at 20w......no where near xmax and 100db at 30hz for a single drive unit. Add a pair and room gain and it's enough to chase anyone out of a room.[ATTACH=CONFIG]48175[/ATTACH]

[lorenmjones]

Re: Is there interest in a large three way "monkey coffin" collaboration?

Oh!! I modeled sealed. That's the difference.

????

Unibox has always been my goto modeling program and been accurate to measured outdoor response but YMMV. Here's my excursion plot at 20w......no where near xmax and 100db at 30hz for a single drive unit. Add a pair and room gain and it's enough to chase anyone out of a room.[ATTACH=CONFIG]48175[/ATTACH]

Now ive always been practical where space is concerned and never really understood the whole stand mounted thing. In essence, we're taking up the same footprint wether a stand or enclosure so why waste the space and volume?.......just me of course.

There's always been the whoop a$$ factor of a 15" woofer over a 12 in my experience. They just do bass better to my ears. From a size standpoint, a 12" driver is certainly more practical........but a monkey coffin by definition isn't practical either so why dance around with it! lol Go for broke. If there was enough in the budget, i'd suggest TWO 15's per side. BAM!