Understood and agree about the latex
When I say almost all of it is sanded off , I mean there is like trace amounts left. It almost appears like a grainy discoloring (in spots) rather than something you would think is paint. And this last little bit is only still there because it is really tenacious. So I feel good about it.
-Tony
When I say almost all of it is sanded off , I mean there is like trace amounts left. It almost appears like a grainy discoloring (in spots) rather than something you would think is paint. And this last little bit is only still there because it is really tenacious. So I feel good about it.
-Tony
Harper Status?
Earl, what's the latest on the Harper? Any more information and / or pictures?
I'd like a pair for a bedroom system. How much subwoofer do they need? Think a couple of these would do the trick?
Parts Express 8" Sub
Thanks!
Jim
Earl, what's the latest on the Harper? Any more information and / or pictures?
I'd like a pair for a bedroom system. How much subwoofer do they need? Think a couple of these would do the trick?
Parts Express 8" Sub
Thanks!
Jim
Jim,
I'm not Earl
but I do have a PE 8" sub in my bedroom. On that basis you may find 2 of those suitable on an 'entry' level. I don't think they will keep up with the Harpers wrt dynamics or playback level...the PE subs will distort, noticeably, before the Harpers as you crank them up. It depends a lot on your intended listening level.
I'm not Earl
but I do have a PE 8" sub in my bedroom. On that basis you may find 2 of those suitable on an 'entry' level. I don't think they will keep up with the Harpers wrt dynamics or playback level...the PE subs will distort, noticeably, before the Harpers as you crank them up. It depends a lot on your intended listening level.
you might want to read my post from the "Multiple Small Subs - Geddes Approach" thread:
http://www.diyaudio.com/forums/showthread.php?postid=1872613#post1872613
This method enables you to get low bass from a small sealed enclosure, if you have the right drivers.
col.
http://www.diyaudio.com/forums/showthread.php?postid=1872613#post1872613
This method enables you to get low bass from a small sealed enclosure, if you have the right drivers.
col.
Re: Harper Status?
Just finishing up a large batch of Harpers this week and will test this first production lot and ship. The Harpers are no where near as efficient as the bigger speakers, but I do find that the large number of inexpensive subs out there all seem to be very low in efficiency. You can make this up with numbers, but remember that being located about the room they will add more like 3 dB than 6 dB. So lets say your sub is 85 dB efficient, it would take at least three to be competitive with the Harpers, and then they probably wouldn't have the same MaxSPL - efficiency is not MaxSPL. I would think that three subs >90 dB would be best, two if they are say 94 dB. Never use just one.
When I suggest many smaller subs, I was not thinking about the uber-low efficiency that some of these subs seem to have. That can be a problem.
jdubs said:
Just finishing up a large batch of Harpers this week and will test this first production lot and ship. The Harpers are no where near as efficient as the bigger speakers, but I do find that the large number of inexpensive subs out there all seem to be very low in efficiency. You can make this up with numbers, but remember that being located about the room they will add more like 3 dB than 6 dB. So lets say your sub is 85 dB efficient, it would take at least three to be competitive with the Harpers, and then they probably wouldn't have the same MaxSPL - efficiency is not MaxSPL. I would think that three subs >90 dB would be best, two if they are say 94 dB. Never use just one.
When I suggest many smaller subs, I was not thinking about the uber-low efficiency that some of these subs seem to have. That can be a problem.
Many of the inexpensive small subwoofer's out there are trying to achieve very low bass in a very small package by increasing the efficiency at say 25hz at the expense of efficiency at 100hz. It seems to be mostly accomplished through extremely heavy cones and very long excursion. I'd argue that even stuffing the ports on some of the units out there (for ported units) would still not net the type of performance Dr. Geddes was looking for when recommending the multiple bass speakers approach.
I wonder if a clearer recommendation might be to suggest twp bass speakers, which few commercial examples exist for, and a single ultra low bass speaker (I know this is more commensurate with your specific recommendation, but I recall also seeing that it doesn't matter what you use, or that three subs are fine). In other words, I think diying is the best bet for those low bass speaker setups. I'd bet that a few 8" or 10" pro-bass drivers in sealed enclosures, which could offer 94db's of sensitivity and probably handle no more than 150 watts and be doing just fine. In fact', since the recommendation is for two, I'd suggest getting a single amp rated at 2-300 watts, which is optimized for 4 ohm loads anyway, and drive both woofers off that amp, which would net the 4 ohm load.
I had three subs which would be better classified as ULF instead of what I needed, which was more of a bass augmentation speaker. The drivers in two of them were the Dayton RS 12" SQ subs, which have good upper bass extension, so I thought would work great. However I was having a lot of trouble fixing some issues in the upper bass range, and upon closer measurements of those speakers at close range, I found they were more rolled off above 80hz than I had realized. I switched those drivers out with 12" B&C drivers and sure enough the response switched quite drastically to having less of the ultra low stuff, but more efficiency and a flatter response in the upper area of it's usable range. This seemed to improve consistency and smoothness in the room as well. The difference in measurements are relatively small, but I seemed to have a bit of phase cancellation at one part of the range when the subs where in correct acoustic phase in another part. I also had somewhat of a response hole between 70hz and 150hz, with an over-abundance of bass below that point. This seemed to help deal with that problem. The 12" B&C drivers were picked up as recones from a local craigslist add, and are less than ideal long term solutions, but I plan on changing to the bandpass option Dr. Geddes is offering in the future anyway.
Point of this long post is that as I continue to fiddle with my bass response, i find that the closer I get to Dr. Geddes own setup and specific recommendations, the better things are. Initially I had found a pretty sizable improvement in the response just utilizing multiple subs in various parts of the room. However problems still existed, and while it fixed some, it also seemed to create some minor ones. I found that three true subwoofers with response optimized for bass down into the 20-30hz range are less than ideal for this application.
I wonder if a clearer recommendation might be to suggest twp bass speakers, which few commercial examples exist for, and a single ultra low bass speaker (I know this is more commensurate with your specific recommendation, but I recall also seeing that it doesn't matter what you use, or that three subs are fine). In other words, I think diying is the best bet for those low bass speaker setups. I'd bet that a few 8" or 10" pro-bass drivers in sealed enclosures, which could offer 94db's of sensitivity and probably handle no more than 150 watts and be doing just fine. In fact', since the recommendation is for two, I'd suggest getting a single amp rated at 2-300 watts, which is optimized for 4 ohm loads anyway, and drive both woofers off that amp, which would net the 4 ohm load.
I had three subs which would be better classified as ULF instead of what I needed, which was more of a bass augmentation speaker. The drivers in two of them were the Dayton RS 12" SQ subs, which have good upper bass extension, so I thought would work great. However I was having a lot of trouble fixing some issues in the upper bass range, and upon closer measurements of those speakers at close range, I found they were more rolled off above 80hz than I had realized. I switched those drivers out with 12" B&C drivers and sure enough the response switched quite drastically to having less of the ultra low stuff, but more efficiency and a flatter response in the upper area of it's usable range. This seemed to improve consistency and smoothness in the room as well. The difference in measurements are relatively small, but I seemed to have a bit of phase cancellation at one part of the range when the subs where in correct acoustic phase in another part. I also had somewhat of a response hole between 70hz and 150hz, with an over-abundance of bass below that point. This seemed to help deal with that problem. The 12" B&C drivers were picked up as recones from a local craigslist add, and are less than ideal long term solutions, but I plan on changing to the bandpass option Dr. Geddes is offering in the future anyway.
Point of this long post is that as I continue to fiddle with my bass response, i find that the closer I get to Dr. Geddes own setup and specific recommendations, the better things are. Initially I had found a pretty sizable improvement in the response just utilizing multiple subs in various parts of the room. However problems still existed, and while it fixed some, it also seemed to create some minor ones. I found that three true subwoofers with response optimized for bass down into the 20-30hz range are less than ideal for this application.
pjpoes said:
Matt Thats quite true. From an advertising point of view, they can say "28 Hz LF response" and "large excursion capability", both things that ring to the novice as "good". They just forget to note that an 85 dB senitivity makes them pretty useless unless you buy a half dozen of them.
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