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

[cjd]

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

So I'm sure there are other options out there, but I modeled quite a few woofers this evening. I looked through all of what PE has as well as Madisound and Meniscus. I limited price to $100 or less. I'll post the WBCD graphs FWIW. I've come to the conclusion that the DCS380 sealed or the DCS305 vented are the best option for this. They will both work very well in 100 to 110 liters. The 380 has a couple db more output above 40 hz and the 305 has a bit more from 30 db down. Personally I'd pick the ported 12" but the DCS380 is very appealing as well.

I do understand the concern regarding the need to keep the impedance up to reasonable levels and if that is deemed imperative then the DS315-8 woofer looks pretty good.

So, thoughts or suggestions for other woofer options I've missed?

Here are basic FR graphs for the ones I modelled.

Tune lower. Shoot for the slope to be -6dB before the tuning frequency knee drops it off. What (additional) series impedance are you modeling with?

Also, pay attention to port resonance issues and target crossover region/slopes - make sure your woofer can play comfortably high enough. Higher order slopes can actually push impedance lower than nominal, so a "4ohm" may be 3 or even less (that's the problem I ran into on mine.))

[ngjockey]

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



Above is a quick WinPCD graph using "factory" FRD/ZMA files for a DS315 and a single DS135 (rated 86.9 dB). The tweeter isn't important right now. Since it's not measured in box, BSC is not factored in and has to show on the graph. The crossover is the same as I used for the abandoned "Matterhorns" project I posted recently. Not pushing the DS, but they have FRD/ZMA files.

So, basically, what I'm saying is that you might have to give up some bass for efficiency of the woofer, espescially if you want 2 mids and you don't want to pad them down.

[lorenmjones]

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

Good input. This is the kind of stuff that I have been guilty of overlooking.

So is shooting for a woofer that is good for second order LP at 350hz a good starting point for thinking of something like this.

I wasn't modeling with any additional series impedance. What is a reasonable number assuming iron core coil. 0.3 ohms?

The DCS305 is tuned at 22 hz in the alignment I posted.

Here is a different alignment...smaller box of 90L, walls covered with foam, .3 ohms series imp for crossover, 20 hz tune. Shallower rolloff. F3/6/10 are 24/19/15. Max output is just shy of 108db. Xmax is good at 120 watts down to below 20 hz. Will this work better for most rooms?





Here is DCS380 sealed and stuffed 100 liters. F3/6/10 is 34/27/21. Qtc is .76 and Xmax is exceeded below 30 hz with 150 watts and max output 109db.

Tune lower. Shoot for the slope to be -6dB before the tuning frequency knee drops it off. What (additional) series impedance are you modeling with?

Also, pay attention to port resonance issues and target crossover region/slopes - make sure your woofer can play comfortably high enough. Higher order slopes can actually push impedance lower than nominal, so a "4ohm" may be 3 or even less (that's the problem I ran into on mine.))

[lorenmjones]

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

I'm not attached to two mids. I was thinking two would be needed for efficiency (when I was looking at the 5" mids).

I think most of the woofers are 89 db or thereabouts. I just thought we would need a mid with a little more than that in case some needed to be given up to BSC. But again I don't understand these things all too well.

[ATTACH=CONFIG]48123[/ATTACH]

Above is a quick WinPCD graph using "factory" FRD/ZMA files for a DS315 and a single DS135 (rated 86.9 dB). The tweeter isn't important right now. Since it's not measured in box, BSC is not factored in and has to show on the graph. The crossover is the same as I used for the abandoned "Matterhorns" project I posted recently. Not pushing the DS, but they have FRD/ZMA files.

So, basically, what I'm saying is that you might have to give up some bass for efficiency of the woofer, espescially if you want 2 mids and you don't want to pad them down.

[lorenmjones]

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

We need everyone's input on this. I am thinking the goal is full range over loud. I think 89 db sensitivity, 108 to 110 db max output and good extension to below 30hz is the concept I have in mind. That pushes toward the non-pro woofers. Do others here think the concept fits better going for 45 hz extension and 95 db sensitivity?

Please chime in. Again I vote DCS315 or DCS380 (main downside for either is 4 ohm imp).

For woofage, there are two ways you can go. And both make sense in their own way. If power isn't an issue, something like the Dayton ST would get my vote. This would get into the high 20's, but be fairly power hungry. For a system that will go as loud as possible on a conventional HT receiver, I would stop at 40 Hz with something like a Kappa 15LF. The bad news is that it only takes 200 watts to get to x-max. The good news is that it only takes 200 watts to get to x-max (and peak at 120dB).

[lorenmjones]

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

I looked at the PK165. It just looked a little ragged starting fairly low in it's range.

Have you used the Faital or heard it.

I would think the Faital or the Celestion would be nice.

The Faitals are nice. Really nice.



Dayton PK165. It surpised me just how much better it was than the Alpha 6. Don't know if it will handle the abuse that the Eminence will, but I doubt that's a problem here.

[Erich H]

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

There was a thread started on the AVS forum about a month or so ago for a similar project. The first model was going to be a very big speaker, then work down to smaller models.

Here's the thread: http://www.avsforum.com/forum/155-di...s-maximus.html

It seems most people were hoping for high sensitivity, max ouput, and at least low 30hz range output. So pro woofers were chosen to hit those marks.

[cjd]

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

Undersized box in those models. Bump it up to see why. Then make an educated choice on trade-offs. .3 to .4 is good. 350hz 2nd order takes a special woofer IMO. Target 4th order. May still only take 2 components and a zobel.

20's or sensitivity will drive some of this. To hit a box size and do one or both in addition, you need to up your budget.

[Mayhem13]

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

My apologize...........I meant to nominate the DC380......not the S. When you mentioned 4ohms, I knew I made a mistake somewhere.

[isaeagle4031]

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

I model with .5 to .7 ohms added in for a woofer. I hate to really suggest a crossover point until we know more about the drivers. Generally though, a 350-500hz cross is good for a starting point.

[andy19191]

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

We need everyone's input on this. I am thinking the goal is full range over loud. I think 89 db sensitivity, 108 to 110 db max output and good extension to below 30hz is the concept I have in mind. That pushes toward the non-pro woofers. Do others here think the concept fits better going for 45 hz extension and 95 db sensitivity

A sweeping generalisation:
- if the target is an F3 of 45Hz and a sensitivity of 95dB then it is nearing Econowave 2 way territory.
- if the target is an F3 of 25Hz and a sensitivity of 89dB then it is nearing standard hi-fi territory.
- if the target is an F3 or 35Hz and a sensitivity of 92dB then it is big monitor territory.

[lorenmjones]

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

I did model them larger as well. I've heard Jeff B say before that he's found a gentler rolloff to work better if extension is down in the 30 or below range, a slight hump in response if it rolls off above 60 or so then a kind of max flat alignment in between. I'm sure this is a gross over simplification of his thoughts on the matter. So I think the smaller low tuned box looks ok to me? Others?

Or am I being crazy here and the focus should be on a driver labelled a woofer not a subwoofer.

I have no hard and fast targets. I'm curious what other people think would make a build like this appealing. I feel like 89 db sensitivity, 3-4cf, output into the 20's vented or mid 30's sealed is doable at the price point. Perhaps I'm wrong.

Or perhaps a more broad appeal would include 45hz but 92 db sensitivity with the same box and budget goals?

Undersized box in those models. Bump it up to see why. Then make an educated choice on trade-offs. .3 to .4 is good. 350hz 2nd order takes a special woofer IMO. Target 4th order. May still only take 2 components and a zobel.

20's or sensitivity will drive some of this. To hit a box size and do one or both in addition, you need to up your budget.

[lorenmjones]

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

I think those categorization a make sense. I was always thinking in terms of a hifi type build here.

The higher sensitivity side is very well served by Erich's offerings at diysoundgroup IMHO.
And apparently they are coming up with some to cover the monster 3 way with huge output and efficiency demographic so to speak.

A sweeping generalisation:
- if the target is an F3 of 45Hz and a sensitivity of 95dB then it is nearing Econowave 2 way territory.
- if the target is an F3 of 25Hz and a sensitivity of 89dB then it is nearing standard hi-fi territory.
- if the target is an F3 or 35Hz and a sensitivity of 92dB then it is big monitor territory.

[wg_ski]

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

I looked at the PK165. It just looked a little ragged starting fairly low in it's range.

Have you used the Faital or heard it.

The Dayton "sounds" less ragged than the Alpha 6. For smoothness (among Eminence mids) I prefer the Beta 8, but that's a little big for this. I did a shootout between the three when re-building my truck sound system. I originally has Alpha 6's, and I compared them to the Daytons and the Faitals because I had both. Either one was a step function improvement, and the Faital was a bit better. But the sensitivity was a tad lower on the Fatial, along with the chamber size requirements. The real decision maker was that the Fatial performed so much better on a horn than any other 6" I've tried, so I saved them for that development effort - the Daytons got installed in the truck box.

The Faital will still be plenty sensitive enough to use with a 15 for a project like this - regardless of whether it goes the 89dB or the 95dB route.

[andy19191]

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

I think those categorization a make sense. I was always thinking in terms of a hifi type build here.

I thought you wanted an old fashioned big monitor and so putting some work in to define the objectives as you are doing looks like time well spent.

From my perspective I don't see see any real benefit of an F3 in the 20s but I can see a real loss of efficiency and SPL in order to get it. But that is just one view and others will no doubt have different ones.