PE dayton 2-way Xover NOOB Question

[dyonge]

Hi guys I love this site, so much to read. I am attempting to build some speakers that are incorporating 2 Aursound 3in drivers and 2 dayton audio 3/4in neo-dome tweeters in each cabinet (bipole design). My question is, I have some dayton audio 2-way crossovers that cross at 4.5k and was wondering about the low pass section. It allows the use of 4 ohm or 8 ohm woofers and I am planning on wiring 2 woofers in series so they appear as an 8ohm load. However I Stupidly ordered the 8ohm versions of the auras not thinking that I needed the 4ohm ones for some dumb reason. This may be a dumb question but if I wire the 8ohm auras in parallel so they become a 4ohm load, how does that work out in terms of what the amp sees. The entire configuration is as follows per speaker: (2) 3/4 dome tweeters, 4ohms ea. wired into 8ohms. (2) Aura 3in. at 8ohms ea. wired in to 4ohm. Im a noob to all of this so im guessing that the impedance mismatch between the low and high pass sections is a problem. I dont know how the amp "sees" the speaker configuration so I do not know if the xover combines the two different loads or if the amo sees each driver and has to handle each load. Heh, I'm an artist trying to be an engineer....please be kind!! I'm not sure If im even asking all of this right.
Thanks in advance,
dyonge

 

[Kent Smith]

I think I understand what you're asking here.... If you're using a transistor amp, no problem, as the amplifier will dump whatever current the load needs, even if that load impedance varies over frequency. Truth is, all speakers have an impedance that varies vs Freq.! Even just a single full-range driver has a rising impedance at the high end, and big impedance bump at resonance (low end).

Now if you're using a tube amp, it gets a bit more complicated....

 

[sreten]

Hi,

ditch the stock crossovers and use the info here :

http://www.zaphaudio.com/audio-speaker20b.html

You should get a bipole suited to free space use.

/sreten.

 

[dyonge]

Thanks for the link, I have been to zaphs site before, lots of good info. In a bipole configuration, would I have to change his crossover design to accomodate the bipole setup. Would I be building a xover for each set of drivers in the speaker or would zaphs xover be able to accomodate the extra drivers. Sorry, im a little confused as to how they arrive at the nominal 4 or 8 ohm impedance seen on store bought speakers. I need these to be 8ohm over all because my current stereo cant drive 4ohm loads. (onkyo tx-ds-575). I am wondering how the xover bombines the loads. Am I correct in thinking that Zaph's xover is in parallel? Sorry if im asking dumb questions. Thanks to anyone who takes time to answer!
Time to read some books.
dyonge

 

[AnthonyPT]

Hi
A bit off topic but cannot start new thread. Was a nice
xover design I believe!
I am looking for a crossover schematic and or board
layout for the Electronics Australia loudspeaker kit
that was available from Jaycar as the JC30. The Jaycar
6.5inch driver and maybe the D19 Vifa are almost history
so I don't think it will be stepping on toes to get it.
I have one JC30 crossover but it is well glued in
the inductor department. I want to get a stereo pair
going. Can anybody out there help?

regards

AnthonyPT

 

[sreten]

Hi
A bit off topic but cannot start new thread. Was a nice
xover design I believe!
I am looking for a crossover schematic and or board
layout for the Electronics Australia loudspeaker kit
that was available from Jaycar as the JC30. The Jaycar
6.5inch driver and maybe the D19 Vifa are almost history
so I don't think it will be stepping on toes to get it.
I have one JC30 crossover but it is well glued in
the inductor department. I want to get a stereo pair
going. Can anybody out there help?

regards

AnthonyPT

Huh ? what do you mean you cannot start a new thread ? /sreten.

 

[sreten]

Thanks for the link, I have been to zaphs site before, lots of good info. In a bipole configuration, would I have to change his crossover design to accomodate the bipole setup. Would I be building a xover for each set of drivers in the speaker or would zaphs xover be able to accomodate the extra drivers. Sorry, im a little confused as to how they arrive at the nominal 4 or 8 ohm impedance seen on store bought speakers. I need these to be 8ohm over all because my current stereo cant drive 4ohm loads. (onkyo tx-ds-575). I am wondering how the xover bombines the loads. Am I correct in thinking that Zaph's xover is in parallel? Sorry if im asking dumb questions. Thanks to anyone who takes time to answer!
Time to read some books.
dyonge

Hi,

Zaphs crossover is for near wall with minimal BSC.

so if you redesign for 4ohms, i.e. drivers in parallel, you will be fairly near.

To do this halve all resistor and inductors values, double capacitors.

But you want 8 ohms and a bipole, sigh ..........

Nevermind, wire the driver pairs in series :
double all resistor and inductors values, halve capacitors.
You will get an easy to drive speaker.

/sreten.

 

[dyonge]

Thanks for your posts sreten. As I am reading more and more, I have realized I kinda paid the idiot tax on those dayton xovers. Oh well no worries, I'll use them for something. I should have bought kit speakers first. I will try what you told me and see what I get. By the way I tried the little 3in auras in some mahogony cigar boxs and they sound pretty amazing for their size an cost. Thanks again! I have to learn this stuff so I can attempt a project with the fostex drivers or maybe some of those jordan metal drivers. This stuff is very addicting!!! And now I need a better amp!!

 

[dyonge]

I forgot to ask, If im doubling the inductor values, one iends up as 1.6mh and the closest value madisound has is 1.5 or 1.8, Is it ok to use one with a close value to what you need? sorry I dont know this stuff. I am resaerching to find answers as well..I'm not trying to get you guys to do the work for me.

 

[sreten]

I forgot to ask, If im doubling the inductor values, one iends up as 1.6mh and the closest value madisound has is 1.5 or 1.8, Is it ok to use one with a close value to what you need? sorry I dont know this stuff. I am resaerching to find answers as well..I'm not trying to get you guys to do the work for me.

Hi,

It depends what the component is used for how near you need to get.

1.5mH should be ok in this case, though you could unwind the 1.8,
(if madisound can tell you how many turns it actually has).

/sreten.

 

[dyonge]

Hi Sreten, thanks for your response! What about caps. By halving the values for those, I end up with non common values. If I have a 1.65uF value, can I use a 1.5uF etc...? or a 4.3 or 3.9 for a 4.1 value. Also, I am guessing that you want have all the caps be from the same manufacturer as well, correct? I am finding that the different manufactures have different values. Some have a few really close to what I need while missing other values by a few tenths of a uF which points to the mixing of capictor brands, which doesnt sound like a good idea to me. Im thinking that i may just scrap this design and just make those little mini wall mounts that zaph built. The cabinets I built are modded cyburg needles as I was originally looking at full range drivers.
Thanks for any response, happy holidays!
Dyonge

 

[sreten]

Hi,

For capacitors you can parallel different values and quality.

/sreten.