XPS MLTL Measurements
I removed some stuffing and it helped a lot.
Mic is at 30 in height and 1 m from speaker. Looks like bass extension matches my prediction of circa 30 Hz. The tweeter doesn't look like it kicks in until 10 kHz though and there is a cone breakup peak at 4 kHz. Not sure what is causing bass peak at 100 Hz - room effect?
The measurement is with tone controls for treble boosted and flat.
Sounds pretty good except that I can hear the difference in lack of clean tight bass articulation (as opposed to Nautaloss) , I can really hear the deep bass but it is a little jumbled as evidenced by ratty looking impulse response.
I removed some stuffing and it helped a lot.
Mic is at 30 in height and 1 m from speaker. Looks like bass extension matches my prediction of circa 30 Hz. The tweeter doesn't look like it kicks in until 10 kHz though and there is a cone breakup peak at 4 kHz. Not sure what is causing bass peak at 100 Hz - room effect?
The measurement is with tone controls for treble boosted and flat.
Sounds pretty good except that I can hear the difference in lack of clean tight bass articulation (as opposed to Nautaloss) , I can really hear the deep bass but it is a little jumbled as evidenced by ratty looking impulse response.
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Did you ever try a pair of the ApexJr tweeters I mentioned. IMHO, they have a price/performance ratio similar to the Vifas.
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I was thinking of the same thing as I recall you used it with the DNA horn with success. I need to get some of these. I also have a cheap Pyle PH44 CD horn tweeter but that will require a bypass cap and some resistors to pad down.
It's a small world wesayso - I have those in the "Coppers" TL project from the PE forum. I agree it's a top shelf driver and a bargain at the current price - I paid the full shot. Though very nice, the ApexJr tweeters don't approach that performance level and X is a true low cost curmudgeon , so......
BTW - I have the same problem X had with too much stuffing in the Coppers. Unfortunately I built them without a removable panel so have to do some MDF surgery to get at the inside. I spent big bucks building up a high gloss piano black finish on those so it will be a real shame to destroy all that work.
, so......BTW - I have the same problem X had with too much stuffing in the Coppers. Unfortunately I built them without a removable panel so have to do some MDF surgery to get at the inside. I spent big bucks building up a high gloss piano black finish on those so it will be a real shame to destroy all that work.
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Crossed at 3-4K I'd pick the Vifa XT25SC90... very good for the money. But it wouldn't be a full range project with helper tweeter anymore
I have been looking at those Vifa's too - nice units and are on sale for $18 at PE. However my entire XPS MLTL project costs $12 ea
I am going to have to build a set of speakers one day that doesn't use budget or blowout drivers. But half the fun for me is to make something that sounds good for almost nothing. My sims and builds seem to compare for the most part so I may try venturing into a real driver build one day soon. Having way too much fun with these drivers for now though. When are you going to fire up those 2 towers?
You mean secondary radiated sound from thin enclosure walls are being picked up in the measurement? I can try wrapping the box with a blanket and see what happens. That may be the cause of that 100 Hz resonance.
It's a small world wesayso - I have those in the "Coppers" TL project from the PE forum. I agree it's a top shelf driver and a bargain at the current price - I paid the full shot. Though very nice, the ApexJr tweeters don't approach that performance level and X is a true low cost curmudgeon
BTW - I have the same problem X had with too much stuffing in the Coppers. Unfortunately I built them without a removable panel so have to do some MDF surgery to get at the inside. I spent big bucks building up a high gloss piano black finish on those so it will be a real shame to destroy all that work.
Can't you just reach into the cabinet through the driver cutout and pull out the stuffing? Use a wire hook for the tight crevice or the bend. Post cabinet surgery is never fun and I have run into the excessive stuffing problem a couple of times now. I am finding that lining the walls surrounding the driver with open cell foam really helps. I am not seeing any big reflection induced problems.
I covered the speaker with a thick -35 deg mummy style sleeping bag. The double zipper was perfect for allowing both the driver faces and port to be exposed while the rest of the cabinet was covered.
I see no difference - which is good from the standpoint of people wondering how much the foam walls contribute to the sound. In this case - negligible. In fact, the covered case seems to have slightly higher SPL?
I am pretty sure the 100 hz peak is a room feature as it shows up when I turn on my other speaker at this same mic position.
I am debating whether or not to build the matching stereo pair. Big speakers are rather time consuming to build with lots of bracing required... Hmmm...
There were some reflections from nearby walls/objects than once removed produces a better impulse response -similar to the standard exponential decay ringing that I saw on the single driver version of the OB. So the impulse response can be cleaned up a bit with placement/room treatments.
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The one on the left shows with and without sleeping bag cover. The one on right is no sleeping bag but placed differently in room to clean up impulse response.
I did not use any ratchet straps - don't have any but was trying to cover up radiated sound from walls of enclosure and not trying to affect the mass/densities of the walls.
Both, as you proved.
Foam core or similar construction can't handle much in the way of pipe TL/horn action. Great for damping high Q systems where the cab's 'breathing' is ~uniform though.GM