altoncustomtech

I agree with the others, there will be a lot of modification needed to do it right. The only thing those foam ones are good for is protecting a speaker from the elements and they do that at a small cost to accurate response from my limited experience with them. I'm slowly making plans to do about the same thing in the future with the Jimmy. My plan is to build ported enclosures for a pair of 8" mid bass speakers utilizing the current hole in the door panel for the tweeter as the location for the port. I'll have to cut away some of the door to make room for the enclosure to slide into the door cavity and the enclosure will bolt to the door. I planned on sealing them with resin and bed liner to protect them from the elements as well. My plan was to make the enclosure with a step out where the port and mid bass would be flushed up to the door card. The enclosure would be nearly as tall as the door cavity and as wide as can fit between the front of the door cavity and the window track (approximately 9.5") and the back will curve with the outer door panel to get as much volume as possible. My point is that if you're willing to take the time to plan it out well and put in the effort on the custom work I don't see why it couldn't be done. At the same time I know it would be much easier to sell them and buy a driver that better fits the goals AND the application. Either way I look forward to the build and am very interested in how it turns out if you do go through the trouble of stuffing enclosures into the doors.

Well, I wasn't thinking of the ski pass as having anything to do with resonance, at least directly. My thought only went to that of a 6th order bandpass as mentioned, though the helmholtz effect would make more sense and could definitely be at the root of the cancellation issues. The same way it does in the design of mufflers in a car. I was only trying to refer to the resonances of the materials of whatever reflective surfaces should the OP open the rear speaker holes in the rear deck. Like I said, sub bass frequencies wouldn't be anywhere near the resonant frequency of the glass and probably not that of the sheet metal either. My original statement still stands though. Everything in the environment has some affect on the response, especially anything in between what's making the sound and where the listener is hearing it. Even in an open room the surfaces of the walls, flooring, and even the furniture can affect the response the ear picks up.

Everything has some affect. Coming through the ski hole kind of makes it like a 6th order band pass since there is some length for the waves to travel through the opening, it's like a port. Close that off and unblock the rear speaker holes and it will affect it completely differently. There's little to no length involved in getting through the holes, but they're still holes plus the waves will be reflecting off of whatever is above the rear deck. Be it the glass or the roof both surfaces have their own effect on the sound waves and then there's the angle of the reflection and what it bounces toward from there. While these reflections can have a much larger effect on higher frequencies due to the shorter wavelength and higher resonant frequencies of the surfaces involved it does still have an effect on low frequencies too. The holes the bass is traveling through probably affect the end result that your ears perceive more than the reflections would. I'm not an acoustic engineer at all, but the little I've been able to learn and seemingly understand leads me to that conclusion. I'm absolutely certain that if I'm wrong on that theory Sean, Brad or someone who really actually does know will correct me on that.

Adjustable? As in still passive but with the ability to adjust the crossover point? If so, not without a great degree of difficulty and even then I don't think there would be much range at all. I'm trying to imagine the circuit design for it at the moment. I know attenuating circuits are easy and it seems like I've seen plans somewhere that used some very uncommon parts to make an adjustable passive crossover, but that could just be my memory getting it crossed up with another circuit design. I have seen some passive's that have a switch that physically switches the electrical path through different components to change the crossover point, however I don't look at that as "adjustable" just changeable. To me "adjustable" would indicate being infinitely adjustable, like a potentiometer. Going active would be much easier in the control department, though cost more to complete.

to the forum!! I don't think you'll find a more well rounded bunch of guys with a more well rounded collection of information on any other forum. On top of that we all take a lot of pride in trying our hardest to ensure that information is as accurate as possible so that no one gets misled along their path of learning.

Three things to check. First verify your tuning is accurate by using your tone generator again and watch to see at what frequency the sub moves the absolute least amount. That will be your tuning frequency and in most cases should be relatively close but just be sure. Have you tried moving the sub around yet? Generally gaps like that in the frequency response are due to acoustic anomalies that cause cancellations and such. The last thing to check is all the settings on your HU and amp to make sure you don't have a low pass filter that's turned down in that neighborhood somewhere. Checking and verifying the tuning of the enclosure can help ensure there's nothing goofy with the frequency response from being tuned abnormally low or something. Very uncommon issue, but it could happen. In all likelihood the issue is an acoustic one. You'd be floored by how a few inches or a few degrees of rotation can affect the response of any speaker or sub in a car. They're a horrible environment from an acoustics standpoint. I'm sure you've checked your settings, but hey, shit happens sometimes. There's been plenty of threads over the years where someone has had an issue like this, fought it for a week or two and then discovered something they thought they had previously checked but missed. Verify all that stuff and lets see what you have after that. I'm sure others will have other ideas as well, those are just the first few places I would check. Another possibility is that the sub simply doesn't respond well into that range, but I would tend to doubt that train of thought for several reasons.

Well, so much for the best of intentions. Pulling the oil pan just far enough to clean the surfaces that were leaking and seal them with RTV should only have taken most of a day, two days tops. This afternoon I was able to get the pan loose and drop it down the better part of an inch to clean the front up and seal it but of course, with my luck it can't just be that simple. When the oil pan dropped down the rear part of the gasket stuck to the engine block. Even though I was successfully able to get it loose without breaking it I can't get it back into the groove in the back of the pan so that the pan can go back into place. So now I'm going to have to tear apart half of the underside of the front of the truck to get the front axle out of the way so I can drop the entire pan down and out. Then if there's any luck left at all in my life I can get the gasket back in the groove where it belongs, clean all the surfaces that need RTV on them so it will stick and seal, get the pan back into place without screwing up anything else and then work to get the front end put back together. What should have taken some hours is now going to take another week or two to complete. Yay me.

We threw an awful lot at this thing for a week straight. My wife goes to the store, runs errands, etc. everyday so if it had any real shortcomings compared to the Q's I know she would have told me. She doesn't like it when things don't work like she wants them to, lol. The only thing she ever mentioned the first day we had it hooked up was that it seemed a little funny up on the mid bass type frequencies (not her exact words obviously but it didn't take much to figure out what she was talking about). I readjusted the time alignment because the sub was just in the back row of seats instead of behind them like the Q's and I never heard another word about it. Are there improvements that could be made on it? Well, possibly, but at what cost? It's already capable of producing fantastic output from a single sub. It's doing so with enough clarity and quality as to contend with my Q's, and all that at a price point that puts it in league with the three I mentioned in the review. The owner worked this out to be a well rounded sub that stood up well in the lanes as well as being at home in a daily driver setup. I think it would have been very difficult to have gotten much closer to that goal without compromising some of it's best features. If I had the money to spare I'd have picked one up quite some time ago. With all the stuff I do for myself and others around here I need one badly, that's for sure. Maybe next spring.

Thank you for the opportunity to do the testing and review. I've been meaning to build a test enclosure again for awhile now, this gives me a really good reason to do so. I built a test enclosure years ago with interchangeable sub baffles for different size subs. I used wood blocks to adjust the internal volume and had multiple round ports cut for adjusting tuning along with a cover that sealed the enclosure. It was great for goofing with subs before I understood more about enclosure alignments, size and tuning relationships and things like that. It would be nice to have another one, even though it's a lot of work. I'm also working out getting in to get some SPL measurements as well and if it all pans out like I'm hoping I'll have some numbers to post up as well. So here's the pics of the sub. A couple that Shane originally sent and a couple that I took of the sub.

Unloading in an enclosure happens when the sub plays below tuning. However, what can happen in some cases is that one sub will unload prematurely, or before the other sub. Typically it is due to the orientation and placement of the port to the subs. What is typically found is that the sub nearest the internal port opening can prematurely unload. It all depends on the size of the enclosure and the port itself, how close they are, etc. and is therefore very difficult to account for or model from what I understand. Because it varies with every enclosure design it can sometimes not happen at all, not be detectable under normal listening levels, or can be so severe as to shred the sub long before reaching maximum output in the worst cases.

Okay, so at this point I'm sure you're wondering "Who the hell is 93rd Audio?" and "What the hell is a TCH12D2?". I'd be glad to answer that. 93rd Audio is an up and coming company started by a member of the IAK family. The TCH series subs are the first series of subs to be released. They are built here in the USA, it has a 2.5" coil and will have a 600 WRMS power rating. I was asked by good 'ol Porkchop if I would be interested in testing the prototype for this new company and line of subs. No matter what the deal was I wasn't going to pass up a great opportunity such as this so I agreed and he put the owner in contact with me. I was supposed to have a fair bit of time to test the sub, multiple enclosures, different amps, etc. however life being what it is the time table was truncated and I had to work with what I had on hand already. So I borrowed my sister's single 12" enclosure for her DCON which is 2.25cuft NET tuned to 31hz and mounted the TCH in and hooked it up in the van to the SAZ2k. So let me explain here that my testing results aren't as well rounded as I had originally planned on going into this with. The owner was hoping to have a sub that can take a good deal of power and make a presence in the competition lanes. I believe it can definitely do that and I think that it's going to be a fair sub to compete with the Sundown SA12, and possibly even the GCON and the Fi X series in specifications, performance and price point. With no official experience with any of those three that comment is really only an opinion, but I don't come to it lightly. Me and my wife threw A LOT of abuse at this sub and with 2k on tap to beat on it with and I was generally only able to reach it's limits on the most abusive songs at listening levels that belied a single sub. Okay, now with that explained it's onto the review itself. Avenged Sevenfold - Nightmare -- This song is fun to listen to with a good sub setup. It's hard and fast and can sound like a complete and total muddled mess on anything that can't keep up. The TCH had no problem at all keeping up with everything that goes on. I have to imagine when I listen to the song that the band gets a hell of a workout when they play it, especially the bass guitarist and drummer, and that workout carries on to whatever is playing the song. This sub did it fast, clean and with the power it was being fed I never heard it cry out for mercy even once. Offspring - Hit That -- This is another song whose bass lines are all over the map. It has great low end bass lines with overlapping lines in certain parts of the song. On any system I had before I got the Q's those overlapping lines would sound like either a distorted mess or were just a booming bass line. The Q's showed me how detailed those bass lines really were and it was a whole new listening experience that brings a smile to my face every time I listen to it. I am very proud to say I had the same smile on my face with the TCH. The overlapping bass lines were clearly identifiable and the rest of the deep lines were reproduced with the authority I've grown used to from the Q's. Journey - Faithfully -- The name of this song sets the stage for the reproduction of the bass guitar and the drums from the TCH. It was a fantastic, enjoyable and very realistic listening experience and the sub and my components blended together beautifully. The sub is as much at home doing SQ work as it is making the windows rattle. Limp Bizkit - Behind Blue Eyes -- I love the bass lines in this song. They're nice and deep and it's fun to play this song for people who've never really heard a sub system play like that. The TCH was able to drop down and bellow out the deepest tones without any complaint as long as I kept the listening level just below obscene. If I tried to push it into the obscene realm I could hear distortion from the sub that I attributed to being well past it's XMAX. It was well beyond 70% of it's BL and well into the realm of audible distortion but understand that it was being pushed EXTREMELY hard at this point and was louder than an average person would ever try to get from a single sub. Ja Rule - Livin' It Up -- Another fun song to listen to with bass lines and drums that play in an attractive rhythm. The sub had tons of output to give but with the drums on top of the bass lines I was actually able to reach the subs XMECH and got some noise out of it. I was very surprised when that happened but remember I'm driving this single sub to the same output levels that I'm used to hearing with the pair of 12" Q's that I'm used to listening to. Alice in Chains - I Stay Away -- I'm a big fan of AiC and have about every album they've released. I Stay Away is on my top 10 list of their songs and is always cranked when it comes on. The TCH did not disappoint at all with it's ability to keep up with the note shifts and drums. It was a great listening experience with all the output I could ask for. Metallica - One -- My absolute favorite Metallica song. Any system that can keep up with this song at absurd listening levels is a good one in my honest opinion. There's a TON of musical information being thrown at every component of a system and it is pretty easy to overload it and hear lots of unwanted distortion. The TCH was right on par with the Q's on quality, keeping up with those ultra fast bass guitar riffs and Lars' unreal ability to beat the living piss out of the drums. I had a big smile on my face and listened to it twice. The second time I turned the gain knob up more to give the sub a good bit more stress and it still delivered a great performance. I was limited more by the components in the van than the sub. Staind - Outside -- Another great song it has bass lines and drums that can play havoc on a sub system. The TCH was able to play it quite well at a very moderately high listening level. As before with a few other songs when I went for the limits of the components I found a little distortion from driving it well past it's XMAX. Keep in mind here that we were almost constantly pushing this sub to the point that it was giving us the same output that we listen to the pair of Q's with. Now we don't listen to them at full tilt, the remote gain knob is generally only turned up about 1/3 of the way, however the fact that a single 12" sub was giving us about the same output and in some cases more gives credence to just how capable it is. My wife would have complained IMMEDIATELY if she wasn't getting what she wanted from it. The fact I never heard even ONE complaint from her tells me a lot as to how strong a sub this can be as she's consequently been through quite a few in the 17 years her and I have been together, lol. The enclosure I was testing it in and the sub paired together did a great job giving lots of output that sounded fantastic, but I'm absolutely certain that with a little smaller enclosure tuned a bit higher this thing would be able to excel in output levels and given multiples of the same sub in such enclosures it should do very well in the lanes. I think it's ability to also do such a good job in the sound quality department makes it a super well rounded sub that will be at home in the hands of the average listener as well as competitors. I know the owner was wanting it to be able to handle in the 1kw realm for competition use. I tried to test with some degree of accuracy the power I was applying to the sub only to find that it seems my $300 clamp on meter isn't quite as adept to this job as I had hoped. I've never been one to trust clamp test power results anyway so I wasn't too horribly worried about it myself. IMHO it doesn't matter how much power the sub was seeing during the testing. The fact it was able to give so much output for a single 12 and knowing there was 2kw of power available from the amp it was able to take abuse that a lesser sub wouldn't have. The few limitations I was able to find with it, revolving around being able to reach distortion going well past XMAX and reaching the XMECH limits could very well have been negated with an enclosure change as well. I'm looking forward to seeing these hit the market. I think for the price point the owner is going for these are going to be a great choice for daily listening setups and competitors alike. Though I have to say I feel it's going to be more popular as a daily sub given it's superb reproduction abilities. That too is just my opinion and being a fellow team member I hope he understands that. If you're looking for something new to try when they're released I highly suggest trying it out, I don't see how anyone could be disappointed. I do have some pics to post up of it. I'll wait for the okay from the owner before doing so though.

Thanks man. It feels good to finally be basking in the light at the end of the tunnel. Thank you, and I agree the SSA subs are great looking drivers. Even better than that is how they perform. Thank you. That is a Speakon connector. I like to use them because they're so much easier to connect and disconnect, even when powered, and you don't have to worry about shorts once they're unplugged. The box will be coming out any time I have to haul something so it's pretty much a necessity. Thanks bro. Your build is looking great too!

OK, GREAT NEWS!!!! Got the engine completely back into the truck yesterday, everything on it, timing set and the engine test ran. Things went very well with it, it started and ran without much of a problem through the initial start up period and it drove around just fine after that. The only problem with the whole thing is that it appears I didn't get quite enough RTV on the very bottom of the timing set cover where it meets the oil pan and I have a fairly good oil leak right there. It shouldn't be too tough to lower the oil pan back down, clean off the oil and reseal it all while it's in the truck so I'm not too terribly worried about it. Couple that with the fact the enclosure is done and the PR's ready to tune and it's been a good week! Here's a few pics for the fun of it. The engine as everything sits right now. Simply unreal how long this has taken and how much work has been done. This pic turned out nasty, but it gives a great overall view of how it looks. Even came out pretty damn close to what I had envisioned. Here the motor of that XCON can be seen through the plexi, per it's design. It will be so much fun to try to explain to people that there's only one sub in the box and then see the look on their faces when they look through the windows on the top and get this POV. Well, finally some good forward movement!!

I'm not sure why you'd think there wouldn't be. There are cancellations and distortions caused by surface effects, reflections, echoes and so much more in each and every sound we hear in our lives. For the most part they go unnoticed and uncared about because they're not affecting what we are trying to do or listen to at the time. For the average person the only time it becomes an issue is when we are listening to music. If you think you're trying to tackle a tough problem with a cancellation in your bass imagine what it would take to truly tackle those issues in your highs where almost all the frequencies you hear are produced and are much much more affected by those problems. I think you've found your issue. There seems to indeed be a problem with the bass as it's reproduced in your trunk and how it sounds when it gets through to the cabin and your ears. Is sealing the sub and port to the cabin of the car an option? It would eliminate the acoustic affects that the trunk itself is directly having on it. If that's not an option then would you consider spending the time and money to upgrade your front stage to try some dedicated mid bass drivers that could pick up and deliver those frequencies much better authority so the sub doesn't have to do it? Fighting acoustic anomalies is not an easy task. It takes time, trial and error, and many times you still have to make a compromise with more negatives than positives, obviously just not with as many negatives as there were before. On another note this was a very well thought out, well informed, and well posed query. You shouldn't have any problems getting more responses and a solution figured out on this one.

You should never use the bass boost on the amp or on the HU. When you dial the bass boost up you are essentially asking the amp to try to amplify the bass frequencies even more than it already is. There is almost no situation where that's a good thing. The reason why is because it will send the signal into distortion VERY quickly/easily and a clipped signal is a quick way to cause equipment failures. The amp will draw excess current resulting in undue strain on your electrical system and excess heat from the amp. The clipped/distorted output signal going to the sub(s) will heat the voice coils unnecessarily and if it/they are already being driven to the limits of it/their cooling abilities then damage will very likely result. Just trust us, don't use the bass boost. Let your friends destroy their crap with it while you enjoy yours for as long as you own it.

to the forum! Not only is the brand pretty good but the forum itself is a great place to learn about anything audio related.

Awesome, sending PM.

Still have the Dayton midbasses?

I doubt your questions are "stupid", however constantly bombarding someone will end the willingness to help pretty quick. I'm sure most of your questions are like the many we have seen before from someone who's new to the hobby like you. You say you joined the forum so you could talk to Fi, well while they're some of the best and most knowledgable people I've talked to they are very busy AND there are plenty of us on here who can also answer questions. Collectively the members of this forum carry some of the best, most accurate, and well rounded knowledge you'll find anywhere on the Internet. I can guarantee that pretty much any search for information you do on google will have results that include this forum. To that end you can save yourself a lot of trouble sifting through the search engine results and just use the search function that's built into the forum. Please remember that when you do go to ask a question on the forum, be sure to put some thought into what you're asking. Include as much information as possible in your post and you'll get all the help you could ever ask for here. Make sure they're worthwhile and you'll learn more than you could imagine in a shorter period of time than you'll ever believe. There's almost nothing though that's not been pondered, wondered or already asked though so the search should keep you busy for awhile. Be sure to check out the chat room as well, it's amazing what you can ask and learn in real time in there. Welcome to the forum and the hobby.

The Fi X series is just underutilized, and severely so. SSA has the same problem with the DCON and I would suppose even the GCON as well and I'm certain that Incriminator sees the same issues with their two lower powered lines. For some reason everyone thinks they have to have at least 3kw of subs and amps to make a good and loud setup and it's just so far from the truth. My sister's single 12" DCON on ~500watts sounds impressively good, can rattle your teeth just fine, and didn't cost an arm and a leg to pick up. It didn't need $1K in electrical upgrades (none actually) and it gets loud enough, even for me. The Fi X's are targeted toward people who for whatever reason are limited to running in the 500-800 wrms per sub power range. While they can handle more, especially so with the BP option, pushing power levels to them that far over their rating bring the user to the point that the SSD's become the next logical step up and the price difference reflects that, IMO. The X is the more budget oriented line. It's a great sub in it's own right but not quite up on the same level as the SSD. While both are for daily listening setups, both have triple progressive spider packs, both are 3" voice coils, and both have cooling options, the size and configuration of the motors plays to the subtle fact that the SSD will have an edge in output. Neither are going to disappoint though so you/your customer can buy with confidence they're getting a great sub.

They very well could. Back in the good 'ol days, before Class D amps ruled the roost the Class AB amps would get hot enough to fry eggs on, and that's no exaggeration. Back in the mid 90's I traded a US Amps A50HC to a guy who put it on four 15" Rockford subs in an S10 at either 1 ohm, or .5 ohm bridged (amp was .25 ohm stable stereo so .5 bridged was fine). Aside from the fact he had to put 4" C clamps every 6" to keep the fiberglass shell on the bed of his truck that amp ran so hot it melted the carpet on the board it was mounted to. MELTED the carpet mind you and that was perfectly fine for that piece of equipment. So hot you can only hold your hand on it for a few moments is pretty much how it goes for any amp at 1 ohm that's being run fairly good IMO. The amps have thermal protection built into them and I've yet to see that protection fail on anything of any decent build quality so I'd just let it go and start to worry about it when it does go into protect, if ever.

To me, this seems like as good a combination as any. http://www.sonicelectronix.com/item_43838_Precision-Power-PPI-BK1800.1D.html

EVERY speaker is rated for a nominal impedance. Impedance is the resistance measurement that is used because a coil with AC voltage applied is reactive. Depending on the frequency that's applied and the inductance of that coil that resistance changes unlike with DC where resistance is simply resistance. The nominal impedance is more like the average impedance seen on a given driver over its specified frequency range. THAT is why you measure it with a DMM and see a lower resistance than its given impedance. Sure, mistakes happen, but as several have mentioned the resistance of the coil is written on the coil when it is wound. Read it and see what it says. The DC resistance you measure with a DMM WILL NOT MATCH THE RATED IMPEDANCE ON ALMOST ANY DRIVER. Like I said, go to Partsexpress for example and look at the thiele/small parameters for any speaker you want to. The Re (DC resistance) rating will be lower than the given impedance for pretty much every one of them.

Im afraid you don't know as much as you think you do, at least not in this instance. A DMM measures DC resistance only. The 4 ohm or 2 ohm rated "impedance" of any speaker is an AC resistance. Look at the "Re" spec on any sub on the market which is the DC resistance of the coil and it will almost never match the rated impedance and most times isn't even close and can even be about half the stated impedance. You were sent a D4 to start with, and got the D2 you ordered the second time. The fault is yours, not theirs. I'm sorry, but that's the truth of it.

I'm trying to help a guy design an enclosure for an X series 15. What is the mounting depth on the sub? Do you have that information posted elsewhere? EDIT: Nevermind, reading is obviously outside my abilities today. Another scan through the topics in the section found the thread I was after.