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Multi-Way Conventional loudspeakers with crossovers

3 1/2 Way with Sub...My Upgrades
3 1/2 Way with Sub...My Upgrades
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Old 17th May 2020, 09:28 PM   #1
oldspkrguy is offline oldspkrguy  United States
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Default 3 1/2 Way with Sub...My Upgrades

I have MANY drivers and amplifiers. Time to upgrade and re-arrange. On the low end; I have the SB23MFCL45-4 single in a closed box just under 1 ft^3 powered by an older Hypex DS 2.0. I will eventually add a second one but will have to wire them in series for 8 Ohms. The Hypex does great with 4 Ohms but no way could it do 2 Ohms. This won't increase my overall sensitivity I realize but I will still have twice the surface area and I'm guessing I would increase the SPL's because the Amp will have an easier load. I never have to turn the main "gain" control up past the half-way point. With all bass EQ settings, in room response goes all the way down to 14 Hz! Remarkable for a single 9 inch sub. in a small, closed box! The Hypex has a non-defeatable 12 Hz high-pass (I think 4th order?). Moving on up from there...
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Old 17th May 2020, 09:47 PM   #2
oldspkrguy is offline oldspkrguy  United States
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I just received 2 SB29NRX75-6 10 inch woofers. These will go into separate closed boxes for stereo. Box size about 1.2 ft^3 (33 l). This should give me an f3 in the low 40's. I like pipe organ music; including the bigger ones that do 16 Hz. I will use the subs for everything under 40 Hz ONLY (monoral) and the 29NRX for 40 to about 300 Hz or so (to be determined). I have these in test boxes right now for break-in (not ideal but close enough for starters). I am using the Dayton APA 150 amp. for this test. It is actually a very nice amplifier for the money. It can be bridged mono, run stereo or mono, switchable low-pass that has a variable X/O frequency. My next drivers naturally drop off below 150 Hz without any X/O so I set the Dayton for stereo and 150 Hz X/O (3rd order if memory serves). There is an obvious match up problem here as the 150 Hz to 150 Hz doesn't blend very well, a gap if you will. So I set the Dayton for full range and things started to sound better. I have some inductors on order and have many values "in stock" already so I will go passive here. It may just be that the 3rd order rolls off way too quickly; I'll figure that out eventually. I'm going to try the X/O here at 300 Hz first. 1st order then 2nd order if need be. Could be a 1st order on the woofer and 2nd order on the low mid-bass...to be continued; starting a new veggie and flower garden during the Covid stay at home...time to get some much needed Sunshine and fresh air...
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Old 18th May 2020, 12:00 AM   #3
oldspkrguy is offline oldspkrguy  United States
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Break-in period still VERY early. However, my previous "dedicated woofer" were single (one per stereo side) 6 inch Satoris. The new 10 inch SB are not nearly as accurate or focused as the Satoris! This is still way too early to tell obviously but I may have made a major mistake here!?? I was in pursuit of more SPL's in the 40 Hz to maybe 400 Hz range. To be continued as I said earlier...New idea already forming; a pair of 7 1/2 or 9 1/2 Satoris instead of a single 29RNX75??? It just doesn't seem to be nearly as accurate or "musical" as any Satori I have currently...to be continued...
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Old 18th May 2020, 02:04 PM   #4
oldspkrguy is offline oldspkrguy  United States
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Moving on up to mids. I have a Satori 6 inch mid. (MR16P-4) and a MA Pluvia 7PHD (P7PHD). My current system has these running almost full range; no passive or active X/O on the bottom at all. The Satori has a custom 2 nd order low pass with Zobel. I can use the P7P full range or with a small inductor for a low pass (switchable in or out of circuit). These are each powered with separate amplifiers so I can use one or the other or both at the same time and adjust the "volume" of each independently. NOT a typical set up I realize but the Satori and Pluvia used together covering the same wide-band mids. is very satisfying musically. I will stick with this arrangement but now use a passive high pass on each to match up with the new SB29NRX anywhere from 200 to as high as 500 Hz. Most likely I'll end up in the 300 to 400 Hz region. There has been a lot of discussion about comb filtering, etc. having 2 different drivers outputting the same signal but separated in space obviously. I really don't notice this effect very much at all so I am not bothered by the pure science that says otherwise. Remember; I can use the Satori by itself, or the Pluvia by itself or both together and with variable "gain" control over each independently. This is why I am calling this a 3 1/2 way instead of 3 way. 2 different mid range (wide-band, near full range actually is more technically correct) covering the same band width. The upper roll off on these as I am using them is above 6 KHz (natural and/or electrical depending on the Pluvia inductor "mode"). I also realize most people would never use a 6 inch driver all the way up to 6 KHz because of beaming, etc. I am not bothered by this either; a narrower sweet spot is a non issue for me as I am the only listener other than the dog! From there, I go to the Fostex T90A super tweeter with a custom 2 nd order high pass. Details later, still waiting on more parts to arrive...
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Old 18th May 2020, 11:50 PM   #5
oldspkrguy is offline oldspkrguy  United States
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The SB29's are still in the test box; it is obviously too small because the Q is too high. No surprise so I can't judge the sound quality too harshly until these go into their intended box. As for playing around with the X/O; 1st order won't do; 2nd order also won't do so I added a Zobel with the 2nd order. Not bad but there is still plenty of energy well past 2 KHz; I'm hoping to NOT have to go 3rd order but I will if necessary. I have most of the correct L and C parts values on hand to do that; the inductors are 13 and 14 AWG so the DCR is reasonably low. Right now the low pass approximates BE2 with a -3dB at 400 Hz. My Zobel R and C values are a little higher than some calculators suggest but I found that there several different Zobel calculators that give different values so no worries here. I have a hand held DMM with LCR; I think I will try to measure the VC inductance myself. My meter does this at 100 Hz which is OK for woofer frequencies. I wish it would also allow LC testing at 1 KHz and 10 KHz but it's only an inexpensive meter. The SB spec. sheet says the Le is 1.8 mH. Anybody out there know of which Zobel calculator is the best (most accurate)? When I do Zobels for higher frequencies; I usually fudge and raise the R and C values because most spec. sheets give the Le as measured at 1 KHz. For very high X/O's; the inductance is most likely going to be higher (at 10 KHz for example).
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Old 19th May 2020, 12:04 AM   #6
oldspkrguy is offline oldspkrguy  United States
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Quote:
Originally Posted by oldspkrguy View Post
The SB29's are still in the test box; it is obviously too small because the Q is too high. No surprise so I can't judge the sound quality too harshly until these go into their intended box. As for playing around with the X/O; 1st order won't do; 2nd order also won't do so I added a Zobel with the 2nd order. Not bad but there is still plenty of energy well past 2 KHz; I'm hoping to NOT have to go 3rd order but I will if necessary. I have most of the correct L and C parts values on hand to do that; the inductors are 13 and 14 AWG so the DCR is reasonably low. Right now the low pass approximates BE2 with a -3dB at 400 Hz. My Zobel R and C values are a little higher than some calculators suggest but I found that there several different Zobel calculators that give different values so no worries here. I have a hand held DMM with LCR; I think I will try to measure the VC inductance myself. My meter does this at 100 Hz which is OK for woofer frequencies. I wish it would also allow LC testing at 1 KHz and 10 KHz but it's only an inexpensive meter. The SB spec. sheet says the Le is 1.8 mH. Anybody out there know of which Zobel calculator is the best (most accurate)? When I do Zobels for higher frequencies; I usually fudge and raise the R and C values because most spec. sheets give the Le as measured at 1 KHz. For very high X/O's; the inductance is most likely going to be higher (at 10 KHz for example).
I just lowered the R value and raised the C value of the Zobel; closer to ideal now. I am using 4.5 Ohms with 82 uF now; better than 6.0 Ohms with 68 uF
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Old 19th May 2020, 10:18 AM   #7
oldspkrguy is offline oldspkrguy  United States
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I just ordered 2 Scan Speak "Flow Resistors" (Dynaudio called them VarioVents). This is just in case my intended box also has a higher than expected Q. I know I could make my own flow resistors but the ready made ones are a quick, simple fix.

I will line all of the walls with a poly'/felt blend pad and do about 75% stuffing with poly' fill. I can adjust from there; more or less stuffing, with or without flow resistor. The problem is this is a smallish living room and there is really only one location for the speakers that works well. I think there is a room mode right around 40 Hz. The current woofers "excite" the room in this region. With the new woofers; I can tweak this out easier I'm guessing because they will be closed box, not vented. The padding, stuffing and flow resistors give me some flexibilty here. The subwoofer plate amp has multiple bass EQ and management settings so I can null out any deep bass room peaks. It even has a polarity switch which I haven't tried yet.

More parts and materials delivery expected today and throughout the rest of the week. This gives me more break-in time on the SB29NRX's before they go into the final, finished boxes.
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Old 19th May 2020, 10:38 PM   #8
oldspkrguy is offline oldspkrguy  United States
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Tweaking both mids. this afternoon. Received the flat pack boxes for the woofers but that will have wait until the neighbor can help with lifting; carrying, moving, etc.

I think they should probably call the SB29NRX 11 inch instead of 10 inch. These things are massive and built like a tank! I'm sure in the right room; they could SERIOUSLY rock out!

Back to the mids.; The Satori MR16 is one of the best sounding drivers I have ever heard in the 300 Hz to 3 KHz band; The MA P7PHD is one of the best sounding drivers I have ever heard in the 600 Hz to 6 Khz band. Together; they are UNBEATABLE as far as I am concerned! They complement, supplement and blend together "perfectly". Of course, it all comes back to personal tastes but, seriously, for the money, I really think these can't be beat. I have heard the best of the best; these are right up there for sure!

I am currently fine-tuning the balance of these together. I will now use these in parallel with my best amplifier (but still have separate speaker switching available to choose 1 or the other or both); I have very high quality series resistors "in front" of the P7PHD (between the amp and driver). This serves 2 purposes; it attenuates the P7P to better match the MR16 and also keeps the total, parallel impedance of the 2 pairs of drivers within the limits of the amplifier. I have approximately 4.4 dB of attenuation on the P7P; I have also modified the Zobel and custom 2nd order low pass X/O on the MR16 "slightly" (I was very close already; this is just another fine tuning attempt). I am doing this (mids. tweaking) ALL at near field; once the entire system is put in place in the final room configuration, more minor tweaks could be required. The P7P is currently running TRUE full-range; the only thing between the amplifier speaker terminals and the P7P terminals is a short run of OFC twisted, 10 AWG twin lead (ZERO X/O); only the series resistors as I already indicated above.

The only thing left here is to put a series Capacitance in front of the MR16 as a low frequency, high pass filter. The capacitors are still on order and I will need to tweak the values to match the SB29NRX low pass X/O so that is for another day.

I did modify the MR16 boxes slightly as well. These are the PE BR-1 box. I have further modified them so now they are a true SEALED box of about 15 Liters. I capped off the tuning pipe inside; stuffed the pipe with high density foam and pounded in a tapered, rubber stopper from the outside. Before; I only had the foam in the tuning tube so I was getting "some" leakage; the tuning of 37 Hz or so would actually show up! Even though the MR16's are "midrange"; they are very capable of doing 40 Hz! As I said earlier; I am quite sure I have a room mode at about 40 Hz so this killed that particular problem. ( just have to further treat that with the woofers and sub now...to be continued...)...
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Old 23rd May 2020, 02:45 PM   #9
oldspkrguy is offline oldspkrguy  United States
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Starting on boxes; I'm going to try to share some photos. My photo software not the greatest; not sure how this will turn out but here goes:
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Old 23rd May 2020, 02:46 PM   #10
oldspkrguy is offline oldspkrguy  United States
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Originally Posted by oldspkrguy View Post
Starting on boxes; I'm going to try to share some photos. My photo software not the greatest; not sure how this will turn out but here goes:
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File Type: jpg DSCN0656.jpg (655.6 KB, 422 views)
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