Hello,
I have really enjoyed this thread and have a similar situation trying too get a 85-90 dynamic swing about 7ft away without break up. Measuring with a sound tools DB meter on an HTC Sensation Android I get driver distortion @ 82-83 DB's 7ft away on Alpair 7's in OB.
So today I ordered the last gold pair Madisound had in stock. I mostly listen to medieval,chamber, symphonic and jazz. I plan on adding one more driver too OB shown in photo too hopefully get those wide vocal swings with early music and Bruckner quadruple fortissimos with little effort. Subs are currently x over at 130Hz.
Have had a hard time over many years hearing a driver that I prefer over the Alpair 7, that includes my Altec A7's which currently sit in garage!
Ramon
I have really enjoyed this thread and have a similar situation trying too get a 85-90 dynamic swing about 7ft away without break up. Measuring with a sound tools DB meter on an HTC Sensation Android I get driver distortion @ 82-83 DB's 7ft away on Alpair 7's in OB.
So today I ordered the last gold pair Madisound had in stock. I mostly listen to medieval,chamber, symphonic and jazz. I plan on adding one more driver too OB shown in photo too hopefully get those wide vocal swings with early music and Bruckner quadruple fortissimos with little effort. Subs are currently x over at 130Hz.
Have had a hard time over many years hearing a driver that I prefer over the Alpair 7, that includes my Altec A7's which currently sit in garage!
Ramon
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+1 to Monte Verdi. I'm also excited at Bob Brines working to make a successful FAST system with the Alpair 7.3. Bob if you think these will be suitable for a 5.1 or 7.1 home theater set up, maybe some considerations or recommendations for acceptable distance to the rear wall. Forgive me if that is rushing the process when you haven't even proposed your design yet but it seems to me to be a continuing issue at least in my humble home where space just doesn't allow the speakers to come out too far into the room. In any event I'm following your progress with anticipation!
Maybe this is opening an unwanted can of worms but it might be worth considering not only the two 8 inch drivers but also a second 7.3 driver. Wouldn't that help with dynamics? Wouldn't an up firing 7.3 could support ambiance and dynamics? Benefits of the ceiling boundary effect with a front firing driver to keep image and focus intact. I don't know enough to say if it would muck up phase or how any drawbacks would be handled but it would give more Sd and move more air.
Using two drivers in the same frequency band is fraught with difficulties. The comb filtering will destroy the top end. I have not and will not consider doubling the A7's. This does not apply to the bass drivers because the wave lengths are substantially larger than the driver CTC dimension.
Also note that I am not trying to build a death metal speaker. Regardless of whether the A7's can do a continuous 95dB, and that combined with the output of the bass drivers should give at least 85dB 2m out. That's ear damage territory. If the A7's can actually produce 90dB 2m out, then there should be ~40dB dynamic range with an average home's noise floor.
The fact that the twin 8's ar more efficient than a single A7 is irrelevant as I consider bi-amping mandatory. The use of two 8's is produce a large surface area and therefore a sharper wave front on bass transients.
Bob
Also note that I am not trying to build a death metal speaker. Regardless of whether the A7's can do a continuous 95dB, and that combined with the output of the bass drivers should give at least 85dB 2m out. That's ear damage territory. If the A7's can actually produce 90dB 2m out, then there should be ~40dB dynamic range with an average home's noise floor.
The fact that the twin 8's ar more efficient than a single A7 is irrelevant as I consider bi-amping mandatory. The use of two 8's is produce a large surface area and therefore a sharper wave front on bass transients.
Bob
Where would we be without worms? There are some who are quite happy with their dual driver full rangers. I think it's worth a try. You could build 4 dMar-Ken7.3s for example and try different configurations like top and side firing or both front facing. You could switch the second driver in and out for testing. Might try adding a 1.5uf or so cap to the top driver. At worst you'd have a second set of speakers for another purpose.
I fought a D'Appolito system for years and never got it right. Measured OK, but never quite sounded right, never imaged up to my standards. Single drivers (within a frequency range) work much better. I have not heard a better imaging system than a single full-range driver (in stereo pair).
Bob,
I respect and understand your point here but as we both know " The math shows a bumble bee should not fly, but it does". I listen primarily too classical not Death Metal and in my naivete I must try it and hear for myself if I like it, or do I hear a phase/delay anomaly that is intolerable. Just trying to get choral and symphonic swings too manage better not constant ear splitting volumes. I will try it and let everyone know if it works for me!
Also, drivers are rolled off @ 12db starting at 100hz and subs entering at 120-140 Hz and go down to 25Hz.
Thanks, Ramon
The subs are NHT Sub Two's with two 10 inch driveers and one 250 watt Carver/Sunfire
plate amp per cabinet. They also come with a separate cross over box that allows vol, phase, and freq adjustments in low, high and fixed frequencies. They have been extremely useful and sound quite good from 21-200 Hz.
plate amp per cabinet. They also come with a separate cross over box that allows vol, phase, and freq adjustments in low, high and fixed frequencies. They have been extremely useful and sound quite good from 21-200 Hz.
Found a digital Radioshack SPL-meter for sale cheaply in Stockholm. Will take a few weeks for me to get it but when I do we'll see how loud I actually play with my EL70. It will be very interesting to find out
don't be surprised if C weighted fast averages clock in not much above lower 90's -
This, of course, is exactly my problem. I like to set my speakers in an 8' equilateral triangle, and that's pretty close to 2.5m. As a reference, yesterday I had Dvorak's 7&8 playing. I took out the SPL meter on my trusty iPhone and got just under 80dB for the forte's. Another 10dB is what I am looking for to handle transients.
The A10's will make this volume in spades, but we have already had that discussion. I suppose I will have to get a pair of A12p's once they are available.
Bob
Hi Bob, did the alpair play full range? And playing louder than that caused, what? Audible distortion?
I agree that this seems to be the critical question. Bob's scenario pretty much matches my typical listening w/ classical or jazz and I wouldn't consider it very demanding or unusual.
If the 7.3s can't handle this type of music/listening, what exactly is their expected "mission"?
If the 7.3s can't handle this type of music/listening, what exactly is their expected "mission"?
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