Yes, I have several right now that I could photograph. I'll do that this week.
I should add pics of the subs as those are now complete and being shipped. I am very happy with the new subs. They work very well and are a good match to the rest of the speaker line. I will be posting data soon. They are very very strange looking as I tried some new ideas and they worked great. Seems like all my ideas look different - wonder why that is!?
I should add pics of the subs as those are now complete and being shipped. I am very happy with the new subs. They work very well and are a good match to the rest of the speaker line. I will be posting data soon. They are very very strange looking as I tried some new ideas and they worked great. Seems like all my ideas look different - wonder why that is!?
jdubs said:
The thing about WAF is that so many audiophiles want to compete for the same space as the wife. Not good! (Never happen!) Of course there are those situations where this is unavoidable, (in which case I am not sure how one could actually stay married) but in most cases there is someplace that the wife is willing to relinquish for "your" space. (Mine was the dark dingy corner of the basement. When I was finished with it, it quickly became the most populated room in the house - while we are awake.)
Or the flip side of this is why do audiophiles want to actually see their speakers (or amps for God's sake)!? This too I simply do not understand. Speakers are ugly, I'm mean they are not sculpture or furniture, I love those things, but speakers are functional, utilitarian, they need not (and dare I say it!? - should not) be seen. Amps - don't even get me started. Unlike children, audio equipment should be heard and not seen. In my room it is not easy to see any speakers and no electronics.
That is fine for your opinion. I am much different. I like to see my equipment, and may swap out pieces often. And I am willing to bet that many of the people buying your kits are taking pride in their workmanship on building and painting their new speakers. They might even like showing them off to their friends.
I'd much rather that their friends say - "Wow those speakers sound great!" than "Wow those speakers look great!". To me it's all about the music and not much else. The equipment just does not turn me on.
I am well aware that this is not true of everyone. But they have to live with their choices and I'll live with mine.
And I haven't swaped out any electronics in about five years (video excluded - you can count on having to upgrade something in the video chain about every year or so. Either it fails or its no longer acceptable. Both happen to me on about an equal footing.)
I am well aware that this is not true of everyone. But they have to live with their choices and I'll live with mine.
And I haven't swaped out any electronics in about five years (video excluded - you can count on having to upgrade something in the video chain about every year or so. Either it fails or its no longer acceptable. Both happen to me on about an equal footing.)
yeah, I admit to being a bit of a amp junky. Iv'e swapped out at least 7 in the last year (my system is tri-amped). One thing I have discovered through all the amp swapping though is that running the high efficiency compression driver and waveguide from a Tripath TA2020 powered amp by far surpasses any of the over amps I have tried. It has extremely low noise floor and very precise detailing and imaging. I think it is the best chip Tripath ever made and it is a very good combo with a nice compression driver/waveguide.
col.
col.
I just saw these subwoofers, on sale for today only. They are small, only 8 inch woofer. But they may work for some people who want to setup the multiple sub environment , and are very cheap at $79.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-390
t
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-390
t
I think something like that would be ok if you were trying to see what improvements the multiple subs could offer in improving bass smoothness and eveness throughout the room. However, unless being used in a fairly small bedroom system with the Harpers, I would suspect those subs could not keep up with any of the larger speakers such as the Nathans or Abbey's.
If someone was simply gun shy to the multiple sub idea, but could afford it, and owned the larger more powerful speakers, I would think that buying three subwoofers of appropriate size would be best, then just sell the other two if you really aren't convinced in the end. In some cases you may even be able to take them back to where you bought them from.
As I mentioned earler, and Dr. Geddes seemed to confirm, the area of greatest modal density in a room is going to be the upper end of the bass region (below the transition point that is), and this is the area where most common subwoofers have been comprised the most in output. The larger speakers are capable of very loud levels, and for HT, should be doing 105db's for reference levels, with the subs doing the same at the 80-100hz range, and 115 below that point. The large majority of subs, if not all commercial subs, can not do this. These smaller subs, as mentioned here, certainly can not do this.
My purpose in responding here is that I would not want someone to try this, conclude that the bass response was inferior to his previous much higher end and larger single sub, and write off the entire method. especially those using digital eq's, who probably can get a reasonably flat response in their primary listening position with a single sub. Again though, that would be missing the point of this method.
If someone was simply gun shy to the multiple sub idea, but could afford it, and owned the larger more powerful speakers, I would think that buying three subwoofers of appropriate size would be best, then just sell the other two if you really aren't convinced in the end. In some cases you may even be able to take them back to where you bought them from.
As I mentioned earler, and Dr. Geddes seemed to confirm, the area of greatest modal density in a room is going to be the upper end of the bass region (below the transition point that is), and this is the area where most common subwoofers have been comprised the most in output. The larger speakers are capable of very loud levels, and for HT, should be doing 105db's for reference levels, with the subs doing the same at the 80-100hz range, and 115 below that point. The large majority of subs, if not all commercial subs, can not do this. These smaller subs, as mentioned here, certainly can not do this.
My purpose in responding here is that I would not want someone to try this, conclude that the bass response was inferior to his previous much higher end and larger single sub, and write off the entire method. especially those using digital eq's, who probably can get a reasonably flat response in their primary listening position with a single sub. Again though, that would be missing the point of this method.
Matt
Good points. It always amazes me how inefficient the low-end subs are. That allows to advertise big amps, but these amps and those speakers are not really going to produce high level LFs without overloading badly. I have not been as adamant about this issue in the past focussing on the need for numbers, but output level is s serious consideration. The subs that I have are about 90 dB / watt 1m (free field) which is actually very high since they use the 12TBX100 driver which is very efficient. Many of these subs are down in the low 80's which means that two or three of them is barely the same output as one of mine. It takes two or three of mine to keep up with the larger Geddes speakers.
Good points. It always amazes me how inefficient the low-end subs are. That allows to advertise big amps, but these amps and those speakers are not really going to produce high level LFs without overloading badly. I have not been as adamant about this issue in the past focussing on the need for numbers, but output level is s serious consideration. The subs that I have are about 90 dB / watt 1m (free field) which is actually very high since they use the 12TBX100 driver which is very efficient. Many of these subs are down in the low 80's which means that two or three of them is barely the same output as one of mine. It takes two or three of mine to keep up with the larger Geddes speakers.
I would add to that, while I know little about driver design, it does seem that you are often in a balancing act trying to balance efficiency at lower frequencies vs efficiency at higher frequencies. Well, at least this is what driver manufacturs have either told me or implied, that if you want a driver capable of reproducing very low frequencies, especially in smaller boxes, then you must increase cone mass and excursion, and end up limiting the upper range of the driver. In all fairness to these inexpensive subs, or really any manufactured sub at any price, they are trying to achieve bass into the solid 20hz range in the smallest possible package. Even the very large subs some companies make are still small when compared with the box most pro audio drivers would need to have comparable measured response. The big difference being, it's all at the expense of efficiency.
Dr. Geddes, you can probably clear this up for me. When I model a driver using various programs which can do this. If I keep all other factors the same, but increase the cone mass, what I find is that low end efficiency does not seem to increase. Instead I find that the high end of the driver becomes increasingly rolled off, while the low end stays the same. Looking at the excursion and amplifier draw, they also increase. This would imply that increasing the mass of the cone doesn't seem to have quite the effect one would think based on my initial comment of increasing efficiency at the lowest end. I understand it lowers the fs and mms, and thus has effects on other parameters such as BL. I've tried to take this into account in all my models, and I'm wondering if the models are incorrectly representing what happens, or if infact, this is true. If it is true that it mostly just reduces efficiency in the upper end with little benefit in the low end, then why do this at all, why not just use a filter to balance out the repsonse for more even low end.
Dr. Geddes, you can probably clear this up for me. When I model a driver using various programs which can do this. If I keep all other factors the same, but increase the cone mass, what I find is that low end efficiency does not seem to increase. Instead I find that the high end of the driver becomes increasingly rolled off, while the low end stays the same. Looking at the excursion and amplifier draw, they also increase. This would imply that increasing the mass of the cone doesn't seem to have quite the effect one would think based on my initial comment of increasing efficiency at the lowest end. I understand it lowers the fs and mms, and thus has effects on other parameters such as BL. I've tried to take this into account in all my models, and I'm wondering if the models are incorrectly representing what happens, or if infact, this is true. If it is true that it mostly just reduces efficiency in the upper end with little benefit in the low end, then why do this at all, why not just use a filter to balance out the repsonse for more even low end.
Mass does very little below resonance. In any mass-spring system there are three regions; mass controlled, above resonance; compliance controlled, below resonance; and resistance controlled, near resonance. In each of these three regions only the one parameter has any significant effect. This means that the LF limit of any woofer system is its total compliance and nothing else. Since the compliance also includes the box, the box size tends to be the single factor that "sets" the LF response and nothing else really matters. This is true as long as the drivers compliance is much lower than the box (usually the case). So a given driver in a given box fixes the LF limit and nothing that you do passively can change that.
Do keep in mind that arround resonance the response depends a lot on the box design. For example, a ported box is a HP filter and hence resonance sets the LF limit, But a bandpass has resonance as the center of the passband, so a bandpass is able to go substantially lower in frequency than a ported box in the same package space. But well below resonance everything is limited by the box size even for a bandpass.
Do keep in mind that arround resonance the response depends a lot on the box design. For example, a ported box is a HP filter and hence resonance sets the LF limit, But a bandpass has resonance as the center of the passband, so a bandpass is able to go substantially lower in frequency than a ported box in the same package space. But well below resonance everything is limited by the box size even for a bandpass.
I bought 2 of these to use in broadband application... still experimenting though. I found them on ebay for 140 delivered, each. Don't see them there anymore, but did find a link for them...
http://audiovideodimension.com/jbl-gto1204bp-p-1077.html?zenid=3396e400e74a2f37558305942c016cb8
Bandpass enclosure with GTO Series 12" polypropylene woofer
Medium density fiberboard construction with front-firing slot vent
Sensitivity: 93 dB
Plexiglas front window
Built-in white LED internal lighting
4-ohm impedance
Recommended power: 35-300 watts RMS (500 watts peak power)
Frequency response: 30-150 Hz
20-1/2"W x 17-3/4"H x 14-5/8"D
Doesn't look too bad. My plan is to hide it in a dedicated theater, eventually.
-Tony
http://audiovideodimension.com/jbl-gto1204bp-p-1077.html?zenid=3396e400e74a2f37558305942c016cb8
Bandpass enclosure with GTO Series 12" polypropylene woofer
Medium density fiberboard construction with front-firing slot vent
Sensitivity: 93 dB
Plexiglas front window
Built-in white LED internal lighting
4-ohm impedance
Recommended power: 35-300 watts RMS (500 watts peak power)
Frequency response: 30-150 Hz
20-1/2"W x 17-3/4"H x 14-5/8"D
Doesn't look too bad. My plan is to hide it in a dedicated theater, eventually.
-Tony
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