Low freq. from small drivers? Is it possible


Can you get really low freq. (lets say 30 and down) from a small driver (~6 inch? What is the relationship between driver size and frequency? Most speakers today have went away from a large base driver (10 inches or more). Have we really come that far or is it really a compermize?

Any recomendations for smaller floor standers with good bass?

Thanks,

Dr. Ken
drken
Eldartford.....the reason many enthusiasts buy 3 way speakers is for "good bass" ,not for good midrange.Misconception, of course.A point I think we would agree on.
Sogood51: I liked your post. The comment about ports adding quantity but lacking quality is right on the money. The analogy of a smaller woofers vs bigger woofers and the boy / man comparison was also quite good.

Drew: very nice posts that are based on both common sense and science. Those two factors rarely meet when it comes to audio and audio forums. I applaud the efforts that you put forth in your post.

Michael: Drew never said that other speakers weren't deficient in providing usable spec's. I'm quite certain that he feels that most manufacturers don't provide anywhere near the amount of info that they should about their products, especially speakers. He just said that this speaker lacked the spec's that one really needs to properly judge a speaker on paper.

Given the claims being made for this speaker and the amount of technology that supposedly went into it, one would think that the manufacturer would want to "testify" to the actual performance of the product as much as possible. Your level of involvement / personal emotions seem to be clouding your response on this one. Then again, that seems to be a common situation when it comes to products that you endorse.

Karls: I want to highlight two of your statements. Here's the first one: "It still can't break the laws of physics, but if used within its linear excursion limits, will give extraordinary performance regardless of volume level or frequency".

The only way to maintain "extraordinary performance" with this speaker contradicts the "regardless of volume level or frequency" part of that sentence. That's because as either frequency is reduced or volume is increased, excursion also escalates. As such, what you've said is that "this speaker kicks ass / remains quite linear so long as the volume is kept to a reasonable level and one doesn't expect the deepest bass". As a few posts have pointed out above, you can't maintain high spl's and / or deep bass extension with lower levels of distortion without resorting to larger drivers.

Here's the other statement that i think requires further commentary / clarification: "The issue of the extra power required by the BOMB is more of a problem for the amplifier than for the speaker. The reason for this is that there is surprisingly little energy (on a continuous basis) in the deep bass. But when it appears, it can make very heavy transient demands on the power amplifier. The BOMB has a maximum boost of 10dB at 24Hz, which equals a factor of 10 in amplifier power".

The added power requirement of the amp is most definitely a problem that the speaker shares too. That is, the 10 dB increase in power that the amp must generate has to be dissipated. ALL of that dissipation takes place within the speaker itself. I think that this is why Drew mentioned thermal compression and power handling coming into play more rapidly with this approach than when using a larger driver with less requirement for EQ.

As a side note and to somewhat respond to Drew's comments, my thoughts are that the effects of thermal compression would be somewhat reduced with this design. This is due to the design of the driver itself and the fact that it will make use of the 2" thick metal baffle acting as a heatsink for the basket of the driver. While it is true that the voice coil & coil former are doing most of the dissipation in a driver, the basket and magnet structure also enter into the picture in this area. Given that the basket is mounted to a metal structure that should be quite excellent at dispersing heat, it probably has a sizeable advantage over other designs.

Other than that, this looks to be a very well designed speaker. I remember looking at it previously and thought it was pretty nice, but also way too costly. I do understand that there is a LOT of custom machining taking place here, but $10K for a "little" speaker is still a LOT of money. Then again, $10K for a "big" speaker is still a LOT of money in my book. I do applaud your efforts and appreciate the fact that you didn't try to push some type of bass reflex design on the public in the name of "more is better" bass response.

Bluebull: Actually, if properly done, relieving the midrange driver of the longer excursions necessary for low frequency reproduction, midrange response should be improved. Given that many two ways are a compromised design, it stands to reason that the same engineers would be even more confused when adding another driver, two more crossover points and a lot more parts to the equation. Sean
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I gather that the BOMB speaker utilizes heavy electronic equalization to flatten the response of drivers mounted in a too small enclosure. This is a neat idea, and one that Dr Bose came up with about forty years ago. I hope that patent issues have been resolved. The requirement for a powerful amplifier is less of a problem now than it was back then.

I am unimpressed by the reported difficulty of making the massive aluminum baffle (or whatever it's called). A numerically-controlled milling machine could knock these off at high speed to tight tolerances. Probably cheaper than a fine furniture grade wooden enclosure.
Sean, it is so good to see that you took time out of your busy schedule to go through the above posts and do your typical blessing and discreditdations. In the future, please try to wordsmith your responses to shorten them. Really it is much easier on the reader to not have to spend so much time reading just to realize that nothing constructive or informative was really said.
"this speaker lacked the spec's that one really needs to properly judge a speaker on paper." Absurd, statements like this belong in Audio Asylum under the NEWBIE section.
"Your level of involvement / personal emotions seem to be clouding your response on this one. Then again, that seems to be a common situation when it comes to products that you endorse." Dr. Sean I will try to make an attempt in the future to run my posts by you prior to posting, so that you fully understand their intent and meaning, Furthurmore, its good to see that you have kept track of all my personal enodrsements.

I want to highlight two of your statements. Here's the first one: "Drew: very nice posts that are based on both common sense and science. Those two factors rarely meet when it comes to audio and audio forums. I applaud the efforts that you put forth in your post. He just said that this speaker lacked the spec's that one really needs to properly judge a speaker on paper"

Here's the other statement that i think requires further commentary / clarification: "Other than that, this looks to be a very well designed speaker."

If there is not adequate published specs on the speaker, how can you say it is a well designed speaker? It would appear that your level of involvement / personal emotions seem to be clouding your response on this one. Then again, that seems to be a common situation when it comes to commenting on anything topic.
Michael: Based on the information provided, it is possible to tell that someone invested a lot of time and research into these speakers. Whether or not they do everything well or suitable for a given installation is another matter. The more spec's that the manufacturer provides, the more that one can interpret just how well they might fit their specific needs and desires. Sean
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PS... Thanks for the kind words. I hope you have a pleasant week-end too : )