The new budget speaker king?
- Thread starter oicdn
- Start date
Robie
Live it or live with it.
Just finished the 3uF recap as originally recommended by Analog Addict and Farr Out. Installed 5% Daytons and glued (Household Goop) a piece of waffle foam mattress topper covering the back wall. Port is still open.
Much better highs. Not so sure about the mids. I am going back to Zilch's graphs to see what I'm hearing.
Can't wait to hear from X_25 as to his opinion.
Much better highs. Not so sure about the mids. I am going back to Zilch's graphs to see what I'm hearing.
Can't wait to hear from X_25 as to his opinion.
x_25
Big Vandies!! Mwahahah...
:scratch2: I could have sworn I posted about the mod. Oh well.
Well I did all four of them without a hitch, the highs are defently better, they no longer sound like they are under watter. I still need to track down so wire to make some inductors, but that is pretty far down the list because the speakers will now suffice for what I need them for (surround speakers). Next on my list of things to do is to rebuild my projector. 4 lumens just isn't bright enough.
Well I did all four of them without a hitch, the highs are defently better, they no longer sound like they are under watter. I still need to track down so wire to make some inductors, but that is pretty far down the list because the speakers will now suffice for what I need them for (surround speakers). Next on my list of things to do is to rebuild my projector. 4 lumens just isn't bright enough.
Errmm...thanks for the vote of confidence there. I don't know how much more there is to be done. A conjugate on the woofer might help level out the response a little but I doubt that the results would be worth the expense unless you happen to have the right values on hand. And using a shaping filter to subjectively bring up the bass by pulling down everything else would drop the efficiency into the basement, assuming you're measuring at 1W (or 2.83V). Without having monster power handling a low efficiency would be a killer in that thing as the distortion would be huge as you push it to the limit.
FWIW, when I saw the first set of curves my first thought was to drop the woofer off a whole bunch lower and use the tweeter as low as possible. In other words, I'm not adding anything here as you guys already did that.
Back to sleep for me, gotta sleep off the trip.
Ray
Thanks, Ray, and welcome back!
What I hope everybody ultimately got is that the whole deal was apparent in those initial curves -- what it is, why it is that, and how to upgrade it.
I have one final iteration to post; I got the LF down another 5 Hz to 45 with a different JBL woofer. Just have to put a bit more damping in and verify the measurements, is all.... :thmbsp:
What I hope everybody ultimately got is that the whole deal was apparent in those initial curves -- what it is, why it is that, and how to upgrade it.
I have one final iteration to post; I got the LF down another 5 Hz to 45 with a different JBL woofer. Just have to put a bit more damping in and verify the measurements, is all.... :thmbsp:
Either would be fine; just keep the DCR low, i.e., larger gauge wire. Looking back, I spec'd an air core, actually. Lower DCR "I" core is the same price.
There are some suggestions that more resistance in series with the woofer will lower its Fs and might improve the bass response, but I am not versed in that approach. Gordon or Ray will know about that. I just go for low DCR intuitively to maintain amp damping factor....
archie2
Addicted Member
I have a pair of AR 4X and that's quite a statement.
Well, subject to verification, of course.
Those woofers are available new from Harman Consumer for $108 apiece, BUT, you might find something similar in PE listings, or real ones, used, uhmm, you know where to look.... :thmbsp:
archie2
Addicted Member
Well, subject to verification, of course.
Those woofers are available new from Harman Consumer for $108 apiece, BUT, you might find something similar in PE listings, or real ones, used, uhmm, you know where to look.... :thmbsp:
Well lets see now. My original $15.00 budget speakers are now approaching the vicinity of $300.00. My AR 4X's cost me $50.00 in exceptional shape. So I think I'll come close enough with just 4.7 uF Dayton caps, 1 mH air coils and a little fiberfill for a total of $20.94 both speakers shipped. LOL.
archie2
Addicted Member
Zilch, just a question on the inductor value in your Presidian mod (or more accurately my budget mod. of the Zilch mod). If I used a 1 mH inductor on the woofer wouldn't that take it down a bit too much, to about 1500 Hz, even though it's a 1st order crossover? Would I hear a hole in the mid range?
Indeed, you cannot take the component values of a 2nd-order crossover and use them 1st-order.
Look in the crossover component selection charts in the PE catalog for a 1st-order approximation of what I have done. You'll have to expand the lowpass chart up into the range of interest.
OR, just buy the additional components you need to do the full 2nd-order ZilchMod....
Look in the crossover component selection charts in the PE catalog for a 1st-order approximation of what I have done. You'll have to expand the lowpass chart up into the range of interest.
OR, just buy the additional components you need to do the full 2nd-order ZilchMod....
archie2
Addicted Member
Looks like I would need a 0.20 mH inductor and a 3.3 uF capacitor for a 1st order crossover.
I'm looking at the highpass chart in the PE catalog, 12 dB/octave, 8 ohms, and my 4.7 uF/0.5 mH seems to be in the 3000 - 3500 Hz range, which is 5.7 - 6.6 uF for first order, 6 dB/octave. Frankly, since we're working close to the lower limit of that tweeter, I'd probably use 5.1 or 5.6 uF (maybe even your suggested 4.7 uF) to start.
Then, moving over to the lowpass chart, 3 kHz is going to be 1/10 what is required for 300 Hz, so 0.425 mH, or 0.319 mH for 4 kHz, no? But, looking back at the response curve and recognizing that it's woofer nasties we're trying to shut down, and that there's plenty of them in that region (a peak at 4.5 kHz for starters,) I might take it as low as 2.5 kHz with 0.509 mH (0.5) and see how that sounded.... :yes:
archie2
Addicted Member
A 4.7 uF cap would take the tweeter down to slightly below 4000 Hz. Can it go that far down without accumulative damage? Don't think I'd want to limit the woofer to less than 3500 Hz using a 0.38 mH coil. The shallow roll off of 6 db slope might just seamlessly connect the woofer and tweeter. What do you thikk?
What 3.3 uF does is shown in my most recent post (Cyan).
Consider also that the tweeter impedance is not 8 Ohms in the region of interest here:
Perhaps you'd feel safer with 4.3 uF?
Again, you're wrestling with dilemmas that are best resolved via going 2-pole, in my view....
Consider also that the tweeter impedance is not 8 Ohms in the region of interest here:
Perhaps you'd feel safer with 4.3 uF?
Again, you're wrestling with dilemmas that are best resolved via going 2-pole, in my view....
archie2
Addicted Member
What 3.3 uF does is shown in my most recent post (Cyan).
Consider also that the tweeter impedance is not 8 Ohms in the region of interest here:
Perhaps you'd feel safer with 4.3 uF?
Again, you're wrestling with dilemmas that are best resolved via going 2-pole, in my view....
Oh you are absolutely right about it best being resolve by a 2 pole. But I refuse to commit these budget speakers to the higher priced variety, even if they sounded better. I've got plenty of small speakers that sound better. My local Thrift store has a pair of Baby Advent II's, surrounds intact, for $30.00. Better deal all around. Maybe I'll go buy them. I've never heard a pair although I once had one of their big brothers, the Advent Legacy. Zilch, thanks again for letting me pick your brain.
