Impious

Or you could just drill a small hole in the divider to wire the subwoofers together inside the enclosure, then just have a single run of wire to the amplifier. Saves having to stuff multiple wires into the terminal cups. Or if your amplifier has dual outputs as some mono amps do, you could just wire the subwoofers individually to the amplifier.

I don't have full details of your test methods, but I would that you could hear a .5db difference in subbass with a BTL playing at the level of 2-3kw. (or in most circumstances for that matter). In the more sensitive regions of the hearing (midrange, for example) at certain listening levels where your ears aren't being stressed I would agree it's possible for someone to notice a .5db difference, although they probably wouldn't describe it as a difference in volume but rather some other subjective term such as a change in "warmth" or "detail". But in the subbass, especially at high listening levels.....no, probably not. Chances are I could keep playing the same test tone over and over at the same SPL and you'd think you were hearing differences.....especially if you were expecting there to be differences. Unless there were extremely stringent testing conditions maintained, over a multitude of test sessions to verify results, and correct interpretation of the results (you could simply guess and average a right answer 50% of the time) then you probably didn't test anything at all.

Maximum you're looking at a difference of 1.76db. That's before accounting for power compression, which at 2-3kw is going to be significant. Easily significant enough to knock that 1.76db well below the 1db mark. Which means no difference to the ear. Worth it? Not in a setup designed primarily to listen to music with. Definitely not with the added cost of the amplifier and electrical upgrades. If you plan on hitting the comp circuit on the weekends then yes it might be a worthwhile upgrade.

In that case, yes.....just go for a single amp

Can't say without knowing if the subwoofer is D2 or D1.

Class GH is basically a class A/B output stage with a different type of power supply that switches rail voltages based on demand. It's more efficient during operation because it only switches to the higher voltage rails when demand requires it, otherwise it stays on the lower voltage rails......but I'm honestly not sure off hand if efficiency at full power output is improved.

two d2 rl-p 18s. the reason i ask is because i bought the twisted 8 gauge speaker wire not thinking about it, and would waste a bunch if you see what i mean. Then why bother strapping them? Run one amp per sub and call it a day. Matching them isn't difficult by any stretch of the imagination. It would take 15 minutes max with a DMM and some test tones.

That doesn't account for amplifier efficiency. At a low impedance or with a class A/B design, efficiency may drop to as low as 55-60% at full power output. 1000/.6 = 1667 1667/14.4 = 116A That's a significant difference in amperage draw.

Spiral upcut user here as well. Used it for flush mounting for the first time not long ago and results were great.

I had an old '88 Bonneville many years ago. It had a thick rear deck board material with basically flooring carpet over it. The car had a place for 6x9's in the rear deck, and the rear deck board had some slits where the speakers went but the carpet covered them. One day I got bored and decided to cut out the material above the 6x9 openings. Just doing that little modification made a significant improvement into the amount of subbass that transferred to the cabin, I'm going to guess because there was less restriction to the airflow.

What subwoofer or subwoofers are you using?

Hey Brad whats the difference if any between these four horns, the B&C and Selenium are Titanium while the RCF's are Aluminum. Looking to match them up with the mini-horn bodies. Dont mean to thread jack but this should help others as well when mating horns with horn bodies: B&C DE500-8 Selenium D2500Ti-Nd-8 Radian 450PB-8 Radian 475PB-8 Like Sean said; the differences are going to be as vast as they are with any other driver. There are going to be difference in frequency response, distortion characteristics, sensitivity, adequate crossover frequencies, etc. I have zero experience with Selenium. I've had both the B&C DE500 (in the form of ID CD2Neo horns) and the Radian 450PB (on my Illusion CH1 horns), though they were used on different horn bodies and several years apart so I couldn't even try to make a direct comparison other than to say they are both good and well respected drivers. The 475 is (obviously) supposed to be a little better driver than the 450. The 475 is slightly more sensitive, and on the spec sheet has slightly better rated high frequency extension, and slightly more power handling than the 450. The Radian's also have a slightly lower recommended crossover point than the DE500 and slightly higher rated sensitivity. I wouldn't try to compare the FR measurements on the manufacturer paper as they are fairly obviously different measurement styles. VC diameter is pretty much equivalent between them, but the DE500 has slightly higher rated power handling (though I don't know if rating methods are the same). Really, there's not much info for me to give you any hard-n-fast better/worse differences. Just from personal experience I would feel comfortable recommending either the B&C or the Radians.

I was mentioning 50hz, because that is what some people have been telling me I guess. I'm realistically looking at having the sub crossed at 70 (XCON 12). I like a little more impact from the sub. Problem is, I don't know if the XCON is capable of running up to 70 hz. I had an ED 13AV2 and was told it would exceed 70, but based on an RTA, 63 is where it rolled off fast. I really want a system that is going to give me some hard hitting kick drums, even the tighter metal kicks. Also, here is the site for my mids http://www.dls.se/en...?produkt=en_581 Was the RTA in your vehicle? Reason I ask is that you might have a vehicle-induced roll off around 63hz that is independent of the driver. You would have to RTA it both in and out of the vehicle to determine what affects your vehicle is contributing to the sound.

Why cross your subwoofer so low? No 6.5" driver is going to do justice to a 50hz signal. They just don't have the displacement, and most of them are going to be at pretty high distortion levels playing at any realistic listening volume level down that low. The Carbon's should have a significant increase in displacement over those DLS mids, so they should do better at the midbass. How well they'll work with the DLS crossovers depends on the DLS crossovers. Do you have any details on the crossovers themselves, such a xover frequency and slope and if they have any other built in features such as a zobel network, etc?

http://usdaudio.com/sw/cars/ http://www.imagedynamicsusa.com/forum/index.php?app=gallery http://usdaudio.com/products/wg.php http://www.woofersetc.com/index.cfm?fuseaction=product.brands&category_id=24&brand_ID=36 Or, buy these: http://www.woofersetc.com/p5014/CD-HORN--Image-Dynamics-V2-Fullsize-Horn.htm And pick a compression driver from here: http://www.parts-express.com/wizards/searchResults.cfm?searchFilter=COMPRESSION+DRIVER&srchExt=&perPage=25&sortBy=1&layout=list&page=1&srchPrice=&srchCat=279&srchMfg=&srchPromo=&srchAttr= Or look for used horns in the classifieds of various forums.

Horns will help the stage in several ways. First, because of where the drivers are mounted the pathlengths between the left and right compression drivers will be fairly well equalized, which is important because the frequencies the horn will be playing will still be sensitive to time arrival. Second, the controlled directivity of the horns will create a more even power response than conventional drivers in conventional setups, which is an important factor to creating an accurate soundstage. Having the majority of the midrange originate from a single source can aid in creating more coherence in the sound as it solves some issues that can occur from having a crossover point right in mist of the critical midrange frequencies. This can go a long way to improving the sound stage. The output of the horns will only be matched by using multiples of any other driver that covers the same frequency range. Having a single driver compared to several will eliminate a large portion of the constructive/destructive interference issues that occur by using multiple drivers covering the same frequency range. Eliminating those FR issues will also go a long way to improving the sound stage. Horns use the lower portion of the dash as basically an extension of the horn body itself, allowing the horns to create a nice, high sound stage even though the drivers are located lower in the vehicle. Those are just a few of the advantages. Horns can stage and image extremely well when setup properly, which is one of his goals. His other goal is to obtain high output levels, of which there is no better option than HLCD. And using horns instead of multiple drivers helps eliminate many potential issues. So, in short......horns would meet his every goal without most of the compromises of the other options, namely using multiple tweeters.

Keep in mind that human's have rather poor hearing in grand scheme of things, with fairly poor auditory memory. Chances are good you could have walked someone into the room two days in a row, and they would have perceived slight differences in sound even if no changes were made at all to the system. Even more likely if innocent but subtle hints are inadvertently given. On top of that, we are subject to expectations (placebo effect....if we know something changed we'll expect a difference, and we'll then hear a difference), group think (if one person notices a supposed difference, the others will then "notice" it as well), and the power of persuasion (if you ask something innocent like "Notice anything different?", they'll expect there to be a difference and hence will "hear" one). I'm not saying no differences existed....there very well might have been a measurable and audible difference.....especially if listening position or speaker placement and aiming changed (that's a biggie!). But don't discount the power of psychoacoustics. Sugar pills cure illness every day around the world. Something to think about.

There's not enough information to accurately answer your questions. I can throw out a few possibilities, whether or not any of these are the actual cause I can not guaranty as again.....not enough information,and I am by far and away anything but an expert on acoustics to begin with. What we would really need to directly and accurately answer your question would be.....wait for it.....objective measurements (!) of the system both before and after. But since those aren't available....... First, we'll just air this one out right now.......psychoacoustics. And the typical response to this statement is "I know what I heard, the difference was there! Don't tell me I didn't hear it!" Well, really, without some type of measurement, you can't prove there was any difference. Again, the problem of subjective statements rears it's ugly head. My car system will sound slightly different on different days depending on my mood, what nuances I (subconsciously or consciously) focus on that day, etc. If you tell me your system sounds exactly the same every single day, I'd call you a liar. But, now that we have that out of the way, we can move on to some physical reasons of why you may have heard a change. A change in either listening position or location of the speakers within the listening space will affect the frequency response, and hence can cause an audible change. You might think think the change was minor or unobservable in the space, but audio is a game where inches can make a difference in response shape as it will change the interference pattern of the speakers and their interaction with the room, among other things. Adding/moving/relocating damping material within the enclosure would affect standing waves and reflections within the enclosure, which could be observed in frequency response. I don't know how you accessed the port, but removing a panel/port/driver and resealing it might have caused a change in an air leak which was affecting a particular band of midrange frequencies. If you removed any speaker wire leads, you may have reconnected them in a different polarity (maybe they were incorrectly phased previously, and after reconnection were properly wired in relative phase). There might have been a relative change in frequency response due to the change in tuning which made the midrange seem more pronounced even though it's actual frequency response was unaffected (although the response of the system as a whole changed). From everything I've learned, the port will allow some midrange energy to escape though it. How much and how pronounced depends on a whole host of factors.....but this is supposedly one of the reasons why many home speakers have the port facing rearward, so that midrange energy that escapes interferes less with the direct wave radiating from the speaker. I suppose it might be possible that the tuning frequency and location of the port end in the enclosure or of the bandwidth of midrange frequencies affected/escaping might cause a noticeable difference in midrange depending on the host of factors which affect it (enclosure design, port location, damping material within the enclosure, etc etc). A change in the tuning frequency would change the alignment of the speaker and it's excursion levels at various frequencies, which may have caused a slight change in how the driver behaved in the midrange frequencies (such as slightly affecting intermodulation distortion, etc). My list is not comprehensive, and I can not promise that any single one of those are a contributing factor. It might be none of the above, or a combination of several. Some of them are kinda stretching the realm of audibility, threw them out there as options mainly to just list everything that popped into my head as I sat here typing. And that was just a list off the top of my head, some research into the issue and far more details about the setup may reveal many more possibilities I can't think of off hand or am unaware of. But we'll never really know....since there aren't any objective measurements of the before and after to demonstrate what did or didn't change.

Not without a significant amount of processing......more processing than most processors are capable of. And even then, with the spacing of the mids just in that picture (I don't know what the rest of the setup looks like, if there is anything else) there are going to be some serious limitations and disadvantages to that setup if one were trying to do anything other than get loud with it.

And unfortunately, with far less actual information about Blues Atleast Ultra offered one of their drivers up for measurement, then tried to argue the results. The Blues guys aren't willing to do anything other than argue why we don't even need objective information.

See your other thread. Just means you'll have to set the gain a little higher.

No, no raffles unless they are sponsored by SSA. Either find a single buyer or take it to ebay.

First, you need to learn how to operate spell check. If you aren't already using it, download Firefox.....has spell check built in. Works great. I originally wasn't going to respond as at this point we're . Blues guys aren't saying anything new, important, or informative.......just keep regurgitating the same useless babble, but since I need an excuse to maintain my procrastination of putting up Xmas decorations...... I do. For several reasons. There's far more to it than this, but just briefly.......First, if I find something pleasing to the ear, I'd like to know why. It will help me in the future find other products that I'll quite possibly also find enjoyable if they share similar qualities. On that note, having quantified performance parameters is the only way to objectively compare speakers. I can't buy a pair of every speaker I'd ever like to try out.....being able to compare them objectively allows us to narrow product selection possibilities without having to sample every speaker in person, which is literally impossible. Subjective comparisons are quite literally useless. If I'm going to make a suggestion to someone regarding product selection or consider a product for my own use, I'm certainly not going to do it based on someone else's subjective analysis....Also, if I know some objective information about a speaker, I'll know more about it's limits and limitations, the proper implementation of the driver and in what situations or circumstances it would or would not be a good fit. You're right. But that doesn't mean we can't learn anything from the objective measurements we make. We can do a pretty good job of describing the performance of a loudspeaker and how it will perform (and as a result, sound) with a comprehensive set of objective measurements. Whether or not someone will like that sound and how they will describe that sound is completely subjective and will vary from person to person. What one person subjectively enjoys another may not. So what use are ears when describing or comparing speakers? Who's ears should we use to make these determinations, since my ears and your ears are not going to be the same? Who is the golden eared standard? See below. If you understand the numbers on the piece of paper, those will tell you far more about a speaker than a hundred subjective listeners. Subjective listeners are subject to several variables which makes their listening experience quite useless to me (and anyone else). They are subject to mood, bias, personal preference, and a host of other issues including the scenario and environment in which their experience occurred. No one with subjective experience can tell me more about a speakers performance than a comprehensive set of objective measurements. No one is golden eared enough to qualify as an authoritative source based on subjective experience. Which is a nice thing about objective comparisons.......they can be reliably compared to other measurements made under the same circumstances. Run the software and compare it to predictions or other measurements......if they match up, results are reliable. What? It's like you're just throwing out some terms in hopes of sounding intelligent. For example, you don't think it's possible to compare the linearity of two different motor designs? Then maybe you are one of the subjective listeners who doesn't enjoy speakers that measure well. Maybe you like distortion, maybe you like uneven frequency response, etc. Hence one of the reasons subjective opinions are useless.....you might not like the same performance as I do. Which makes your opinion of something useless for my purposes. But what if we had a way to objectively describe the type of sound you prefer? Wouldn't that be handy! It would take some of the guesswork out of selecting products. Match up the drivers with objective measurements that align well with your objectively defined preference for "good sound", and you'd have a much easier time finding products that meet up with your goals. It seems the only people offering opinions so far are those that have heard the speakers......so I'm not sure why the Blues guys keep saying this? YOU ARE THE ONLY ONES. The rest of us would be interested in more information about the speakers. Or, if someone wants to send me a pair I'd be more than happy to offer my own subjective opinions of the speakers, since that seems to be the only thing that matters to the Blues guys. Please do not compare them to any other speakers. Hearing or owning a product does not qualify someone in and of itself to make any sort of valid comparison against any other product. In many cases, it doesn't qualify someone to make a valid description of the performance of the product itself depending up on type of experience the user has. People think because they have some subjective experience with a product it qualifies them to make absolute authoritative statements about a product....which is absolutely false. And accepting the opinion of an egotistical wad who spouts nothing but subjective opinions and apparently doesn't even understand objective measurements and their use is somehow better? No, in fact it would be far worse. Anyone with even the vaguest understanding of the usefulness of objectivity would be better off to base their decisions on objective information rather than others subjective rubbish. And since you can't seem to grasp this concept.....no one else has commented on their performance. quote=whodat: "Only people that have heard them are capable of making an informed deciision and opinion on if they are good or not". Not the case at all. Listening to a speaker in no way confirms someone as an authoritative source on the performance of a loudspeaker. Certainly they are free to state an opinion, but anyone else would be foolish to accept that opinion as anything other than a single subjective opinion.....and it's certainly not a definitive statement of performance or characteristics. What I may think as "good" you might think sucks, and vise versa. quote=whodat: "Here is aqoute from another thread on this site about the products" I don't care. Nobody here cares except the Blues guys who have taken up the untenable position that subjective opinions matter. Though I really don't know why I'm still wasting my time with this thread, as even if you do respond it will be another worthless attempt to attribute some value to subjectivity when in this case none exists. (had to format those last two quotes differently as I had reached the maximum number of quotes allowed in a single post)

The 2V preamp output just means you'll have to set the gain a little higher. Other than that doesn't mean much. Other than that, should work out fine as long as it has the features you want. Just from a quick glance looks like it has a dedicated subwoofer output which is atleast good to have.

IIRC they even had some people stake out the buyer (I think he was in London or something) at the time of delivery to try to see his reaction and such, but they unfortunately didn't really get anything. The whole thing was hosted on a website years ago. Either way.....yeah, that was some funny shit as well.