RS-P WWMTM 3 Way underway ( pic heavy )

[Jeff B.]

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

While the approach to designing a speaker with flat anechoic response is fairly standard, the approach to designing one that includes the woofer-floor interaction is less standard. Perhaps Jeff B. could explain what his preferred method is.

I still take the gated response on the tweeter axis, which in a room is a bit messy. I also do some modeling. If someone follows my link below and has Excel they can download and use my Diffraction and Boundary Simulator. For the boundary portion I would use the power response and very little, if any, room pressurization. Then look at the combined response with the baffle diffraction simulation included for a reasonable approximation of the low end power response. For a one meter on axis simulation switch the boundary graph to "axial" and then look at the combined graph. It's not perfect, but it helps.

[filmslayer]

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

all measurements from 2 foot ,same amplitude on tweet axis ...

top 125



bottom 125



tweet

[jbruner]

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

Hey, everything looks a lot better when it's flush-mounted!

I think something is causing some top octave loss in the measurements.

Maybe someone who has measured one can confirm, but I believe the Reference silk tweeter has a rising response.

[rpb]

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

Filmslayer.... I know that everyone has there own way of doing things, but what I would do is first make sure that your speaker measurement setup is adequate, and then I'd use gated measurements. Then, I'd take a few measurements of the mids together using a speculated highpass filter. In other words something like 80 uf and 3 mH, and just see what the response looks like. Make a few adjustments, and then add a lowpass to the filter. Something like .6 mH, and 8 uf. If nothing else, you will get some practice, and probably learn a few things as well.

[filmslayer]

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

think i my may have blown up a tweet . i was searching for that top octave this morning and turned the amp up just a bit and ran a sweep , i heard nothing wrong during the sweep but i get no sound out of it now ... gonna finish my coffee before i pull it out and switch it . <sigh>

[filmslayer]

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

switched tweets , other one is ok . putting the suspected bad one back in now ...

**EDIT**

yep , its toast ...

[Chris Roemer]

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

You can just buy new v.c. assemblies for those, I think at about 1/2 the price?

[Thumper Tom]

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

Maybe a NPE cap to put in line to save the tweeter, I think it is 100uf for 4 ohms and 50uf for 8 ohms.

[filmslayer]

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

the pro's and con's of testing un-protected were discussed i made the decision , no big deal , chalk it up to a lesson learned . i'll get a new diaphragm when i order XO parts ...

tried to get more measuring done . took a look between the lower mid and upper woofer , i need to make some changes in Holm to get a better picture . would really like to get some XO parts ordered this week ...

[filmslayer]

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

i'm still trying to get good measurements and just found what may be a problem . my sound card has a microphone boost that was turned up to +24db . will go back and re-measure tonight and see how much of a difference it makes ...

i really can't wait to hear this .

[rpb]

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

Did you by chance miss the HOLM starter guide? Perhaps you can post a picture of your speaker while set up for making measurements.

[filmslayer]

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

not missed (http://techtalk.parts-express.com/sh...-starter-guide) , and thank you !!! its what got me to this point along with their instruction pdf ... i'd rather not post pics of my place , y'all would die of laughter , true story .... Jbruner is privy to my set up and working with me every night as he is the one designing my XO ...

[superspeeder]

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

Great looking build!

I've contemplated a similar design for years, but side-firing the woofers to get a little thinner baffle for improved WAF. If that ever happens (LOL) the RS125P/28F combo would be right at the top of my list. I await your conclusions!

[filmslayer]

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

thankfully i have no WAF .... i have a dog and until she dusts once in a while she has no say !!! :p

[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 ?