2. tech-talk
  3. 1380031366

Question of the day for speaker guru's. Parallel o

I was noting there are quite a few good 2-way and 3-way designs on the market, but in general many suffer from lower efficiency or low frequency deficiency.

What does this have to do with anything? I guess I am curious as to why it would not work to buy 2 of a cheaper speaker that has an 8 ohm nominal load and simply run them in parallel?

It would seem that takes them back to the more common these days 4 ohm load, adds a little efficiency, power handling etc…

I realize that the 2 tweeters in the system and acoustic alignment would suffer.
However, I happened to see this design from Daedulus called the “Ulysses”.

http://www.daedalusaudio.com/Ulysses.html

I guess my point is prove me why not with just taking a design from the 8 ohm styles and double it?

Yes there is 2 crossovers and essentially you end up with 2 “Stereo Pairs” of speakers, but seems like in this Ulysses design specifically the way it’s is oriented in the cabinet it would not be of any significant issue.

It seems the giveaway that something like this ulyssesthis is simply a separated or 2 mirrored with 2 crossover design inside is that it uses not only 2 primary tweeters, but 2 ambient tweeters as well saying to me this is some type of Dual 3-way or dual 4-way system in one cabinet on their own networks?

Would the extra entire crossover run in parallel like this have any detrimental effects to your amp? Seems it would just be a higher power handling / thermal handling, and efficiency per channel?

Also, out of the many 8 ohm monitors that you could essentially stack with the the tweeters flipped to the middle why not using the same theory?

This is more of a hypothetical and technical question over putting it in physical action as of course as in many cases there will be challenges to this, but why not just design a good stable 8 ohm speaker and simply use two crossovers to parallel them together into one cabinet? Seems a bit more efficient and cost effective than many of the exotic designs out there.

Thanks
undertow
mapman's avatar
mapman
22,189 posts
 
I know there are other far more qualified "speaker gurus" out there", but anyhow, be sure to account somehow for the lower impedance that would be in play with 2 "8 ohm" speakers connected in parallel, and make sure everything is wired in phase, and technically I think you should be golden. If done correctly, including good driver symmetry, I think 2X the speaker should almost always be better than 1 (on paper at least), though sometimes with certain room acoustics, less can turn out to be more. Also, there can often be a big discrepancy between theory and practice for many reasons. Try it and let us know how it works out.
jjrenman
279 posts
 
Stacking two identical speakers, with the upper being inverted, gained some popularity in the 70's. You do gain about 6db in (effective) efficiency.

In practice though it does present some challenges. First, the amp is presented a much lower impedance. Often around 2 ohms at some frequencies. Second, the two tweeters are far enough apart that they do not act as a point source over much of the range that they handle which leads to some 'venetian blind' effect.
ngjockey
1,042 posts
 
Since inductor and capacitor values are larger for higher impedance, two 8 ohm speakers wired in parallel for 4 ohms would use extra, bigger and more expensive crossover components than a single 4 ohm speaker like the Ulysses. "Conjoined twin speakers" is possible but not very practical.

In a recent test, I found that two parallel drivers added +4 db over a single driver with a hefty SS amp. Series drivers reduced -1.5 dB. Series/parallel (4 drivers, 8 ohms) added +1.7 dB.

I forget exactly, is it 3, 6 or 10 dB that requires a doubling of power?
More to discover