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

[andy19191]

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

I would only add that the old three ways from Pioneer, Sansui, Scott, etc were pretty efficient systems. They were tuned higher for midbass slam and we're very impressive with classic rock and pop of the era.

Me, personally........my take for something like this is go big or go home......and that includes efficiency and bass extension. I'm happy with the DX25. It's an awesome tweeter at a great price if used correctly. Use it in a small waveguide and you can do LR2 at 1.8khz. That would allow for a nice directivity match to a 6" mid.

I think the design of the speaker is/has moved away from those old 3 ways which is my interest and more towards your big. If the design does switch to a 15" then all 3 drivers will be different, in a different sized cabinet with different sensitivities and bass extenstion with only a shared target price point.

I am not happy with the DX25 for a monitor because of the 4 ohms but appreciate if this big speaker drops to 90dB efficiency or less as suggested by current discussion then it will become less of an issue. The tweeter I have lightly pencilled in is the old Vifa H26TG-35-06 which is currently available locally but whether that will persist I do not know.

The FaitalPro 6FE100 would look a good choice if it was a dB or two more sensitive than 90dB. The current tentative choice is still the well priced, sensitive but more ragged FaitalPro 6FE200. I am still looking for alternatives that do not cost twice the price.

[isaeagle4031]

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

Andy what is the issue you have with a 4ohm tweeter? After series resistance, the top end will probably still be in the 6ohm area and NO amp will have a problem driving that.

[lorenmjones]

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

That would definitely get the job done here. I'm sure it is extremely clean sounding given the sensitivity, FR and power handling. Distortion measurements by Zaph for it were very good too.

Agreed on bass extension.......always low as you can go!

I've used the BC as a dedicated mid only in several projects crossed as low as 1.4khz and as high as 3.5khz where it begins to beam a bit. It's low pass sweet spot for me has been 250hz.

[lorenmjones]

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

Again, I would be fine with a suitable 15" driver...I'd love that. The closest thing I've seen is the DC380-8 sealed. It takes 100 liters just like I've been modelling the ST305 and gives a sealed F3 of about 42 which is very similar in terms of overall bass extension to a vented F3 around 30 esp when room gain is figured in. If we chose that the sensitivity might be 2db higher than the ST305, but again the overall output capability is less due to xmax limited power handling problems in the LF. A vented cab for the DC380 would help a little with excursion problems down low but the cabinet size gets HUGE.

I think the ST305 was your suggestion IIRC. In a competent three way the woofer should clearly be the limiting factor in regards to sensitivity. By choosing the ST305 the sensitivity is higher than it would have been with the DCS 12" or the 15" DCS woofer and I would guess we will end up around 90 db for 1 watt.

I agree the 6FE200 trades sensitivity for a more ragged response compared to 6FE100. The B&C that Mayhem suggested costs twice as much. The ScanSpeak Discovery 15M is a great looking mid driver but is $70 vs $41 for the Faital. I appreciate you searching for a more sensitive mid with a nice smooth response that doesn't cost too much. I think in the overall budget scheme here a mid in the $45 range give or take a few bucks would be good. I linked a TB 6" mid above that has a smooth response and adequate sensitivity but only 15w rms power handling which seems a bit low for this speaker. If you find any great mids for this, please let us know.

Anyway I still think the ST305 is the sweet spot for this project. If you have a woofer that we haven't considered that will be better at a similar price then by all means that would be great to hear about.

Currently I'm still on board for ST305, Fe100, DX25. I think the mid will just match the woofer sensitivity and will avoid the need for burning up amp power with padding resistors on the mids.

I think the design of the speaker is/has moved away from those old 3 ways which is my interest and more towards your big. If the design does switch to a 15" then all 3 drivers will be different, in a different sized cabinet with different sensitivities and bass extenstion with only a shared target price point.

I am not happy with the DX25 for a monitor because of the 4 ohms but appreciate if this big speaker drops to 90dB efficiency or less as suggested by current discussion then it will become less of an issue. The tweeter I have lightly pencilled in is the old Vifa H26TG-35-06 which is currently available locally but whether that will persist I do not know.

The FaitalPro 6FE100 would look a good choice if it was a dB or two more sensitive than 90dB. The current tentative choice is still the well priced, sensitive but more ragged FaitalPro 6FE200. I am still looking for alternatives that do not cost twice the price.

[lorenmjones]

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

I agree on the tweeter.

Hey, isaeagle4031, is there any chance you could accurately measure the real world sensitivity of one of your ST305's at say 200 to 300 hz which would give us a pretty accurate reflection of the sensitivity the mid will need to match?

Andy what is the issue you have with a 4ohm tweeter? After series resistance, the top end will probably still be in the 6ohm area and NO amp will have a problem driving that.

[isaeagle4031]

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

I can pull t/s numbers on them, sure.

[andy19191]

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

Andy what is the issue you have with a 4ohm tweeter? After series resistance, the top end will probably still be in the 6ohm area and NO amp will have a problem driving that.

For the less sensitive design Loren seems to be working towards not much. For a more sensitive, easy to drive, big monitor with the flexibility (i.e. pots and/or switches) to be placed against a wall then approaching the 4.1 ohms of the "Rockin It Old School" monitor is the concern. Since there are alternative tweeters that do not have a low impedance, have a few dB less sensitivity to be closer to the woofer, can handle the power, possibly with a bit of waveguide loading and are close enough in price then picking one seems the right move.

Has picking drivers from PE become one of the objectives?

[isaeagle4031]

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

It would seem so

[jhollander]

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

I can pull t/s numbers on them, sure.

Chuck, the question is what's the sensitivity near the x-o point. If you can't measure SPL directly you can compare with a well known tweeter on a large baffle.

I've got a big piece of cardboard for these types of measurements.

[isaeagle4031]

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

True John. Somehow I deleted the 2nd part of my post and did not notice it.

[speedle]

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

Are we settled on the height? I sure wish it was just a few inches shorter and wider. Like those old AR's and ADS speakers that you'd set on the floor most of the time, but put on 4" stands or maybe a little more, to be hifi correct.

[lorenmjones]

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

I think with this woofer if we set a baffle width at say 15" a person could build it 30" or 32" tall and deep enough to get 70 liters for the woofer and not lose too much LF. Or a person could build it 42" tall and the same width with less depth of the cabinet and get around 100 liters. That will give a slightly deeper LF cutoff. Build it how you like. The only thing I see being an issue with that is how far is the woofer from the floor and how far is it from the mid and how would changes in those parameters with different build heights may affect the system.

Are we settled on the height? I sure wish it was just a few inches shorter and wider. Like those old AR's and ADS speakers that you'd set on the floor most of the time, but put on 4" stands or maybe a little more, to be hifi correct.

[lorenmjones]

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

Andy, what sensitivity and LF extension would you have in mind for this sort of speaker? What woofer would you suggest to meet that goal since woofer will determine sensitivity of the system.

For the less sensitive design Loren seems to be working towards not much. For a more sensitive, easy to drive, big monitor with the flexibility (i.e. pots and/or switches) to be placed against a wall then approaching the 4.1 ohms of the "Rockin It Old School" monitor is the concern. Since there are alternative tweeters that do not have a low impedance, have a few dB less sensitivity to be closer to the woofer, can handle the power, possibly with a bit of waveguide loading and are close enough in price then picking one seems the right move.

Has picking drivers from PE become one of the objectives?

[andy19191]

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

Andy, what sensitivity and LF extension would you have in mind for this sort of speaker? What woofer would you suggest to meet that goal since woofer will determine sensitivity of the system.

For a monitor: target sensitivity about 92dB 8 ohm, F3 about 35Hz ported, box size about 75 litres, SPL of 115dB but settle for >110dB, price £500 total. The woofer at the moment is the ST305-8 despite the price problem but I am looking for an alternative.

For a big floor standing tower: I would want more bass extension, accept less efficiency, easy load less important, accept bigger box, SPL about the same, high fidelity response more important, price perhaps a bit higher because more likely first rather than second speaker. Target sensitivity 89dB 4 ohm, F3 25Hz ported, box size about 125 litres, SPL >110dB, price £600. The ST385-8 15" looks about right but in truth I have not looked closely because, although of interest, I do not intend to build such a speaker in the near future.

[lorenmjones]

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

Well that makes sense and I think what it looks like we are aiming at is a bit of a compromise. ST305 woofer is more sensitive than some other possibilities but prob won't give 92 db, and it's F3 is at 29 as I am modeling it currently. I would think this design could be built in a shorter "monitor" shape box and still easily give you an F3 of 32 or 33 hz with 90 or 91 db sensitivity and adequate power handling to sustain 110 db or a little better. The only one of your monitor criteria that would fall short on would be the sensitivity by 1-2 db. I think you will need to spend a bit more on a woofer that can really give you 92 db, and F3 of 35 in 70 liters. Again there certainly could be drivers under $100 that will do that but I just don't know which. Also your budget at 500 pounds for parts is quite a bit higher than $400. But I do know some parts are pricier there.

For a monitor: target sensitivity about 92dB 8 ohm, F3 about 35Hz ported, box size about 75 litres, SPL of 115dB but settle for >110dB, price £500 total. The woofer at the moment is the ST305-8 despite the price problem but I am looking for an alternative.

For a big floor standing tower: I would want more bass extension, accept less efficiency, easy load less important, accept bigger box, SPL about the same, high fidelity response more important, price perhaps a bit higher because more likely first rather than second speaker. Target sensitivity 89dB 4 ohm, F3 25Hz ported, box size about 125 litres, SPL >110dB, price £600. The ST385-8 15" looks about right but in truth I have not looked closely because, although of interest, I do not intend to build such a speaker in the near future.