Monacor SPH-165KEP + DT-25N DIY project

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Hi,

I've also used the Monacor SPH165-KEP. Mine is a 2-way floorstander 18l vented design using the Monacor SPH165-KEP together with a Seas 27TBCFG (Sorry I don't have any pictures of them).

Ok, I based my initial crossover on the Cheap Trick design, but imho this crossover has 2 flaws .

First the bafflestep compensation, as mentioned by others, is not enough to get satisfactory bass and it will leave you with a speaker that sounds "bright". Bsc is not only about getting bass out of a speaker but also about adding warmth to the overall sound. My guess is that this is actually a sub/sat design which just doesn't work on his own.

Second, again imho, the crossoverpoint is too high. This woofer has breakupproblems at 5 kHz which distorts the midrange if crossed over too high.

What have I done with the filter :

Lowpass :
Certainly keep the first notch as this dampens some mild conebreakup at 1kHz which is noticable (and irritating) when the right music comes by. I changed L2 into 2,2mH giving me much more (and needed) bsc and a lower crossoverpoint. Also keep the second notch as this dampens the breakupproblems at 5kHz.

Highpass :
I changed C3 into 6,1µF by adding a 2,2µF cap giving me a lower crossoverpoint for the tweeter. I kept L4 the same. The L-pad is dependant on the efficiency of your tweeter and it's up to you to experiment with this. Also I'd be carefull because some tweeters might not like the lower crossoverpoint! My Seas 27TBCFG certainly does not have any problems with this.

I'm not saying that this is the ultimate filter for this woofer but it works quite well in my case. Maybe give it a try with some cheap crossoverparts.

In hindsight I must say that this woofer, while not being bad perse when filtered decently, is not the super easy and smooth driver it's often said to be. I simply cannot understand how some people can listen to this by just throwing a coil (and maybe cap) in front of it and be done with it, it doesn't work that way.
I still enjoy these speakers, don't get me wrong, but the next design I'm going to do will be much more quality oriented (think Scan-Speak or Seas woofers here). I know these aren't exactly cheap drivers but most of them have exeptionally low distortion figures, behave quite well in their usuable frequencyrange and have a good overall buildquality.

I hope this helps you out a bit.
 
Thank you Bylie for this long answer. From all the things that I've heard about these speakers it's certain that they are not perfect and have some flaws, but I think they will be just fine as my first DIY speakers. And also they are cheap which was important from the beginning. I'll just have to quiet down the treble on the sound controls a bit and I hope the result will be just fine. I contacted the guy that made the speakers like these and he thinks that they are a good sounding speakers even without BSC. I hope maybe one day I'll build something with Scan-Speaks, but until then...
 
OK, my first DIY speakers are finished!!! I'm impressed. They sound great, far better than my Wh. Diamonds 8.3. Richer mids, strong and deep bass from the beginning. I have a few pics here: http://public.fotki.com/iggy888/diy-speakers/. You can see I didn't spend much for the cables nor for the finish, but this was my first time and now I know how and what to improve the next time. The problem with BSC should be fixed, but other than that - my recommendations for Monacor SPH-165KEP. Thank you all for help.
 
Loiti said:
Due to my Diploma-work, I can offer you Impedance and Phase Data from

SPH-165KEP / CP / 200KE / CTC

These Datas are very important for simulating, and for the most DIY builders not measureable.

Just contact me: stefan@imp.cc

Greetings
Loiti


Loiti said:
Also be careful when using original TSP of 165KEP from Monacor website, these are wrong!

I can also offer you measured TSP from the KEP.

Mfg

Thank you, Loiti, that won't be neccessary. I'm satisfied with the sound and I don't need the measurments. I know about the wrong data on the Monacor's site. My satisfaction is what is important and I don't care much about other things. Thanx anyway.
 
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