Some insight before making any purchases

[xThehavok]

Hey all (noob warning) just joined to get a bit of insight before i make any purchases.

Ill get right to the point, i was looking at using the dayton audio PT2C-8 planer tweeter with 2 dayton audio's DSA270-8 10" woofers per side for the front 2 floorstanding speakers with a 3-4 khz or so crossover and L pad for the tweeter.

Dayton Audio PT2C-8 Planar Tweeter

Dayton Audio DSA270-8 10" Designer Series Aluminum Cone Woofer

I like the woofers but they dont make a 4 ohm version so i can make a 8 ohm load to match the tweeter.

Question is this, can i use the woofers wired in a paralleled 4 ohm load with the 8 ohm tweeter? Some people are saying yes from some google searches but what total speaker ohms would that be? Any other dangers of doing this?

I have a B&K 125.5 that is 4 ohm stable but runs hot enough in 8 ohms for me to want to stay away from that, i already cooked the mosfets (i think) on one channel one night having a 4 ohm sub hooked up and having my system cranked for hours partying my face oof.

Thanks all

 

[Galu]

Question is this, can i use the woofers wired in a paralleled 4 ohm load with the 8 ohm tweeter? Some people are saying yes from some google searches but what total speaker ohms would that be? Any other dangers of doing this?

The total speaker ohms will, to all intents and purposes, be equal to 4 ohms - the sum of the two 8 ohm drivers in parallel. The tweeter's impedance only comes into play at very high frequencies where very little power is consumed relative to bass/mid frequencies.

The combination you have suggested can be made to work with a suitably designed crossover network, but your amplifier must be able to continuously power a 4 ohm load.

 

[freddi]

not including lowpass inductance + DCR, two drivers dips below 3 0hms

 

[Galu]

Thanks freddi!

The impedance curve suggests that xThehavok would be unwise to parallel two of these particular woofers.

 

[ICG]

If you parallel wire 2 drivers, it will halve the impedance (as already said) and therefore it will draw double the power (+3dB). The double cone surface adds another 3dB, that means, you'll always have to check first if your tweeter is loud enough (the Dayton PT2C is). That ofcourse does not apply at an active setup.

 

[cspieker]

That woofer will "beam" at the crossover frequency. Meaning the sound it radiates to the sides will be quieter than straight forward. The tweeter does not beam much at all at 3k. With the radiation pattern being different at the crossover, it will lead to a ragged frequency response curve off axis. Its not that it's not doable, but almost everyone would consider it not ideal. The solution is a smaller woofer. To 3k, many would consider a 6 1/2" ideal. Separate subwoofer to fill out the bass?

 

[xThehavok]

Thanks for the quick replies! I have my heart set on a twin 10" woofer set up with a planer tweeter in a 2 way configuration but if that set up is going to hit the 3 ohm mark sometimes, thats too much. I was looking at 2 of the Goldwood GW-10PC-4 10" woofers with the same tweeter and was looking like it might work but with the RMS of 140 per woofer might be too much for my B&K 125.5 can deliver.

Goldwood GW-10PC-4 10" Heavy Duty Woofer 4 Ohm

What about these Dayton Audio SD270A-88 10" 's? Or is that frequency response not going to cut it.

Dayton Audio SD270A-88 10" DVC Subwoofer

Thanks again guys.

 

[xThehavok]

I know these are both cutting it really close on the frequency side but iw as thinking because theres 2 in each cabinet it might smooth out the response enough to work with a 3 khz crossover. What do you guys think?

 

[jmproductions]

That woofer will "beam" at the crossover frequency. Meaning the sound it radiates to the sides will be quieter than straight forward. The tweeter does not beam much at all at 3k. With the radiation pattern being different at the crossover, it will lead to a ragged frequency response curve off axis. Its not that it's not doable, but almost everyone would consider it not ideal. The solution is a smaller woofer. To 3k, many would consider a 6 1/2" ideal. Separate subwoofer to fill out the bass?

I agree 100%. A 10" 2-way config requires a lot of compromise.

 

[xThehavok]

Oh yes i forgot to reply about the subs, yes im thinking about using 2 classic dayton subs with 2 of daytons SPA250DSP plate amps. Currently im saving my money to buy the house im living in and am only spending enough to get me my 2 fronts up and running and im holding off for about 6 monthes or so before i do the 2 subs, centers and surrounds. What ever i come up with for the fronts ill be matching with the center and surrounds.

Dayton Audio DCS450-4 18" Classic Subwoofer 4 Ohm

Dayton Audio SPA250DSP 250W Subwoofer Plate Amplifier with DSP

 

[wolf_teeth]

You'll need a different tweeter if you want a 10" 2-way.
The tweeter will have to be able to play to around 1kHz cleanly. To get that low requires a very robust dome unit, a compression driver, or a very large ribbon/planar. The candidates in the ribbon/dome areas I could likely count on one hand, and literally dwarf the budget you likely have given yourself.

In short- please don't do this.
Later,
Wolf

 

[jmproductions]

Oh yes i forgot to reply about the subs, yes im thinking about using 2 classic dayton subs with 2 of daytons SPA250DSP plate amps.

In that case you could look at some midwoofer type drivers, giving up a little low freq extension because you'll get it back later. This way you'll get a faster driver that will play mids more accurately, can xo at 2-3khz, and probably also pick up some efficiency. Something more like a pro audio driver would make sense plus you'll not have trouble finding 4ohm.

 

[mashaffer]

I wonder if 9ne could overcome the beaming issue by having the two 10s angled slightly toward opposite sides. How bout having one rear firing so that reflected sound can fill in the dispersion pattern?

 

[Galu]

I was looking at 2 of the Goldwood GW-10PC-4 10" woofers with the same tweeter and was looking like it might work but with the RMS of 140 per woofer might be too much for my B&K 125.5 can deliver.

There appears to be a misunderstanding of power ratings here. The 140W RMS power rating of the woofer simply indicates the maximum power it can handle.

Your B&K AV 125.5 amp of power rating 125W RMS @ 8 ohm per channel will not be overloaded by the speaker.

 

[xThehavok]

Alright guys if anyone is still following this, i went ahead and bought 2 of the PT2-c planer's and 4 of the SD270A-88 10" woofers. On the website they call these woofers subwoofers for some reason even though they hit well past 2000hz. My original idea was i wanted to mimic the Klipche towers that have the 2 10" woofers. I thought for sure i would have less mids and a brighter high but with warmer bass to it, thats not what happened. On my Asus Xonar DX program i have to drop everything past 250 hz on quite a bit. These things scream in the mids and highs but the bass is nice and deep. I planned on getting these and learning hands on what i can learn and i think ive learned this. My next tower build i want to use the same planer's and maybe the same woofers but with a higher tune then 28hz, and maybe put in mids just to segregate the sound a bit better. I went with a rear firing port because i really liked my Cerwin Vega e715's when it comes to their bass. I think i might stick with a front firing port for the next build for easier placement.

All in all these do sound quite good but the mids are a bit much. I can hear things ive never heard before in music and movies. These speakers do alot better with movies with there clearity then music (i like warmth in music)

 

[TBTL]

What did you use as a crossover? From your description it appears that the tweeter is not padded and there is no baffle step compensation (yet? ).

 

[xThehavok]

I have the L pads, just havnt put them in yet, ive been using the digital equilizer on my Xonar sound card program to pad it a little bit, but honestly its the mids around 1-2 khz that are too high.

I just used a out of the box dayton audio 3 khz 2nd order crossover to get up and running, so nothing fancy there. I plan on making my own crossover soon with some baffle compensation. I need to learn a lot more about crossovers before i jump into that though.

Side note, going through some different kinds of music to hear how the speakers performed. Going from rock and metal to han zimmer and a couple rap songs (just to see how the bass was responding). One rap song i was sitting close to my speaker to listen for air leaking from the box and noticed the planars were flexing at the low bass part (20hz or so) had me a bit worried.