RS-P WWMTM 3 Way underway ( pic heavy )

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

OK , i got all the measurements i was asked for zipped up and sent to Josh .

my original thought with these being towers was to use out riggers and spikes for a couple of reason . first the tipping factor and second to get the tweeter up a couple more inches . but after putting one together both those are no longer concerns , it is big and stable and the tweet is rite at ear level as it is . i guess my question is , is there any other audible advantages to spikes that i need to consider ?

[joeybutts]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Decoupling, supposed mid-low end clarity improvement, aesthetics (to me they look "complete" rather than just a box on the floor).....

[rpb]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

OK , i got all the measurements i was asked for zipped up and sent to Josh .

my original thought with these being towers was to use out riggers and spikes for a couple of reason . first the tipping factor and second to get the tweeter up a couple more inches . but after putting one together both those are no longer concerns , it is big and stable and the tweet is rite at ear level as it is . i guess my question is , is there any other audible advantages to spikes that i need to consider ?

I would use something on the four corners to support the speaker. The middle portion of the bottom panel can transmit vibrations to the floor, and the floor will amplify them. The edges of the bottom ar not as likely to be moving. I don't think spikes are required on a hardwood floor, or thin carpet. I used to use plastic bottle caps. A metal disc like those found on chair legs could also work. You could even hollow out the box bottom an eigth inch or so, so that only the side panels touch the floor. If you have thick carpet, you may want to use spikes.

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

thanks guys . i kind of like the look of the round spheres in this thread ,http://techtalk.parts-express.com/sh...tions-for-feet what ya think ?

keep in mind finish will be Duratex ....

[jbruner]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

We are working on a prototype parts list. Here is the latest sim with the measured response from the lower mid. I displayed the factory traces for the woofer and tweeter because they are cleaner, but there was very little difference in the model.



Here's the preliminary parts list-

Woofer
6mH 18/19 ga steel laminate
80uf

Mid
75uf
1.3mH 18/19 ga steel laminate
20uf

Tweet
0.04mH 18 ga air core
1.75 Ohms
10uf
0.2mH 18 ga air core
30uf

I'll provide a range of values for fine-tuning later.

Anybody have cap suggestions for the tweeter? We're not looking to go too upscale. We possibly have Erse 250v and 630v, Crosscap, Clarity Px and maybe Dayton. Should we look at the Audyn Q4 instead? Anyone have a preference? Recommendation?

[isaeagle4031]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Clarity or Audyn. Both are very nice.

[rpb]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

We are working on a prototype parts list. Here is the latest sim with the measured response from the lower mid. I displayed the factory traces for the woofer and tweeter because they are cleaner, but there was very little difference in the model.

[ATTACH=CONFIG]49554[/ATTACH][ATTACH=CONFIG]49555[/ATTACH]



Here's the preliminary parts list-

Woofer
6mH 18/19 ga steel laminate
80uf

Mid
75uf
1.3mH 18/19 ga steel laminate
20uf

Tweet
0.04mH 18 ga air core
1.75 Ohms
10uf
0.2mH 18 ga air core
30uf

I'll provide a range of values for fine-tuning later.

Anybody have cap suggestions for the tweeter? We're not looking to go too upscale. We possibly have Erse 250v and 630v, Crosscap, Clarity Px and maybe Dayton. Should we look at the Audyn Q4 instead? Anyone have a preference? Recommendation?

The mids are only about 12 dB lower than the woofers at 80 hz. I would want a steeper rolloff, and would add a coil to the highpass portion of the mid x-over to get a 12 dB slope.

[jbruner]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

The mids are only about 12 dB lower than the woofers at 80 hz. I would want a steeper rolloff, and would add a coil to the highpass portion of the mid x-over to get a 12 dB slope.

I considered that. The bump is caused by the mid's impedance peak, of course. If we were padding the mids, a parallel resistor could be used. However, in this case, I think we can use stuffing to reduce the impedance peak enough to be useable. I'd like to avoid the extra coil, and will only add it if excursion is an issue during use.

[Chris Roemer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

I'd also shoot for a 2nd order HP filter on the bandpass. This coil can usually be quite cheap (i.e. high DCR, like a #20) and is worth it IMO.

[jhollander]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Maybe save a bit of cost with a damped second order on the woofer and shift some of the load off the tweeter by crossing it higher, esp if these are the 125Ps.

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

good stuff guys ... i'm getting really excited .

[Dabspok]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

In your design you have pairs of four ohm drivers instead of pairs of eight ohm speakers. Is that to make the speaker an easier eight ohm load for the amplifier? Why not single eight ohm speakers?
I try to learn something new from each build I see here. Hopefully I can put ti all to use someday soon.

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

yes it is an attempt to be amp friendly and in series they will handle quite a bit of power .

and i think they look cool as he!! ...

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

we have decided to go with Josh's prototype , he is getting most of the coils ready for me and i ordered the rest of the parts today . we went with the Audyn Q4's for the HP and a Dayton 75uF on the mids . i really hope to start voicing this by the weekend ....

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

looks like i just missed with shipping and the holiday weekend , parts won't be here till early next week . i do plan on getting the other box and baffle done over the long weekend though as i'll have the shop to myself ...