[shnaggs]

So if I went IB, should I stick with a 10”? If I need less power in a IB setup, would 500 watts be enough power for say a IDmax 10 which is rated at 1000w rms?

I like tight punchy bass but have never listened to a IB setup. More musical sounds right up my alley, but would 1 10” be enough? I’m more into SQ than spl

[Ali-E90]

Originally Posted by shnaggs

So if I went IB, should I stick with a 10”? If I need less power in a IB setup, would 500 watts be enough power for say a IDmax 10 which is rated at 1000w rms?

I like tight punchy bass but have never listened to a IB setup. More musical sounds right up my alley, but would 1 10” be enough? I’m more into SQ than spl

If you're into SQ, IB is your best bet, very linear and musical response with little drop off at low freq.

For IB, general rule is bigger is better. Many do 1 15, I did 1 12. I have seen someone do it with a 10w3 as well, but would prob recommend a 12-15" sub.

I used JL because I already had it, but there are other good subs for IB too. Look for the IB thread, tons of info.

[Emilime75]

Originally Posted by david in germany

Emilime75, whoa, so much red! You win.

Really, we agree on about 95% of what you posted with the exception of the 2x power you reccomend. I think it has a lot to do with brand selections. Many brands over rate their amps and may only be producing a much lower power output than they are rated. JL is known to produce rated power and more. Slap a Boss amp rated for 1k watts on a sub rated for 1k watts and you are going to clip the sub to death because the amp is only truly producing 200-250w. I have an extensive classic Rockford Fosgate amp collection and can say with faith that every one of them produce rated power or more.

If I stuck a 150w sub on one of my 25 to life Punch 150 amplifiers and push it, I will be reaching the mechanical limits of the sub quite quickly as the amp actually certified at 1038w rms to a 4ohm mono load ( not max).
Your rule of thumb can only work in some situations.

I'm not trying to win anything, just pointing out something that is incorrect. Also not trying to pick fights or insult anyone. If you don't read anything else, please at least read this.
https://www.prosoundweb.com/topics/education/how_many_watts_loudspeaker/

[kaigoss69]

Wow, never seen so much misinformation in 1 thread!

[kaigoss69]

IB is cheapest and best sounding. A corner enclosure can sound good, but requires careful planning, careful selection of sub and amp, and perhaps some experimenting until you get it right. If you're an SQ freak, and care about integration of the sub into the front stage, I'd say stay away from a corner loaded sub, or any sub that radiates into the trunk. I have NEVER been able to get the corner loaded sub to play up front - even with processing, meaning you could always tell the sub is in the trunk. May not bother some people, but bothers me. IB will give you best sub integration into the soundstage, best frequency response, best efficiency...and best SQ. Did I mention it is also the cheapest?

[Emilime75]

Originally Posted by kaigoss69

IB is cheapest and best sounding. A corner enclosure can sound good, but requires careful planning, careful selection of sub and amp, and perhaps some experimenting until you get it right. If you're an SQ freak, and care about integration of the sub into the front stage, I'd say stay away from a corner loaded sub, or any sub that radiates into the trunk. I have NEVER been able to get the corner loaded sub to play up front - even with processing, meaning you could always tell the sub is in the trunk. May not bother some people, but bothers me. IB will give you best sub integration into the soundstage, best frequency response, best efficiency...and best SQ. Did I mention it is also the cheapest?

I agree with all of this except... how does an IB not "resonate" into the trunk?

[kaigoss69]

Originally Posted by Emilime75

I agree with all of this except... how does an IB not "resonate" into the trunk?

With a traditional sealed enclosure the woofer back wave is contained within the enclosure and only the front wave enters the trunk. In IB the font wave goes in the cabin, while the back wave "stays" in the trunk. There is some cancellation, but the front wave emanating directly into the cabin is the best case scenario.

[Emilime75]

Originally Posted by kaigoss69

With a traditional sealed enclosure the woofer back wave is contained within the enclosure and only the front wave enters the trunk. In IB the font wave goes in the cabin, while the back wave "stays" in the trunk. There is some cancellation, but the front wave emanating directly into the cabin is the best case scenario.

But how does this change the amount of pressure in the trunk? It's still a woofer playing into the trunk. Both sides of the driver generate a full sound wave, it's just that one side is out of phase with the other, and why isolation(either with an enclosure or an "infinite" baffle, is needed, to eliminate the possibility of phase cancelation.

[kaigoss69]

Originally Posted by Emilime75

But how does this change the amount of pressure in the trunk? It's still a woofer playing into the trunk. Both sides of the driver generate a full sound wave, it's just that one side is out of phase with the other, and why isolation(either with an enclosure or an "infinite" baffle, is needed, to eliminate the possibility of phase cancelation.

I'm not sure I follow you, and I don't remember saying anything about resonating, pressurizing or half-waves.

[Emilime75]

Originally Posted by kaigoss69

I'm not sure I follow you, and I don't remember saying anything about resonating, pressurizing or half-waves.

My bad, you're right, I misread your post. Disregard.

[Ishj]

Our BMW trunks aren't sealed. Pressure waves leak out to the outside and to the inside of the cabin. However, the seat attenuates the back waves so much that they don't matter. Also, the trunk is large enough that the change in pressure doesn't affect the driver much(4X VAS at least). On top, the leak to the outside furthur decreases that pressure without creating a port effect. Even if the frequency response is affected even one bit because of the trunk, an eq corrects that pretty quickly. How do I know that? I measured the response with the trunk open vs closed when calibrating my system. No difference whatsoever.

As for power, both my sub and amp are rated for 600W RMS and I run them at an estimated 300W by decreasing the gain to just 3db above the rest. Thats my setting for bass-anemic songs. I furthur turn it down using the bass knob. Gives me lots of excursion headroom and allows for EQ to boost the sub-bass even more if I want to. I'm talking well under 20Hz here, that is what the IB system is capable of!

[kaigoss69]

Originally Posted by david in germany

I am debating if I want to do an IB setup in my 335i with a pair of JL 13tw5s on a small amp. I still have the X series collecting dust as well.

Do it! I really don't see the need for 2 though unless you want to win SPL competitions! For SQ a single 15 would probably be a little better as it will work better with the available trunk volume.

- AE SBP or IB 15 for pure SQ (not much volume capability)
- FI IB315 or IDMAX 15 for SQL

I've heard the FI and it is really good, but I still love my IDMAX the most.

[shnaggs]

Originally Posted by kaigoss69

Do it! I really don't see the need for 2 though unless you want to win SPL competitions! For SQ a single 15 would probably be a little better as it will work better with the available trunk volume.

- AE SBP or IB 15 for pure SQ (not much volume capability)
- FI IB315 or IDMAX 15 for SQL

I've heard the FI and it is really good, but I still love my IDMAX the most.

Is a 15” in IB tight? Obviously this is a different world to me so I lack the knowledge. The most rediculously tight setup I’ve heard was 3 10w3’s in a sealed enclosure. It literally hurt your gut when it hit. Not saying I want anything like that, but I tend to like tight punchy bass. I usually cross my subs around 100hz for reference even though this is a no no.

[Ishj]

Better than tight. Its as precise of a bass as you can get. It vibrates your guts and punches your heart without being boomy. By tight I assume you mean that the response is sort of linear, with no distortion, delays or peaks, especially in the upper ranges. An IB setup is like that. The advantage you have over a sealed setup is how low the frequency response extends. Think of electro songs with that one bass note that is so low it is inaudible. My IB setup plays those at the same volume as other notes. At times I can't even hear the note, but I feel my throat vibrating. At the same time, the kicks are tight and precise.

Note: I chose the FI because ot its huge excursion and specs that lent to a presice frequency response. My measurements in my e90 matched. It was just a steady rise to around 18Hz. I do not have experience with the other subs, I simply chose based on specs. So I'm not in a position to say which you should get

[kaigoss69]

Originally Posted by shnaggs

Is a 15” in IB tight? Obviously this is a different world to me so I lack the knowledge. The most rediculously tight setup I’ve heard was 3 10w3’s in a sealed enclosure. It literally hurt your gut when it hit. Not saying I want anything like that, but I tend to like tight punchy bass. I usually cross my subs around 100hz for reference even though this is a no no.

The perception of "tight" or "punchy" bass is actually a function of mid bass and midrange transients. it has very little to do with the subs themselves. If you cross an IB sub at 100Hz, it may play some of those transients, but the soundstage will be pulled back toward the rear of the vehicle. Better to let the mid bass drivers play those frequencies. If the sub can play them better/louder, then you may have to compromise...

[E92inAZ]

I'm old, I've been building car stereo systems since amps and crossovers were separate units and we were still running equalizers because head units only had bass and treble controls - if you were lucky!
Just for reference, I've got the bavsound uf110 in my car (made for e9x 328's with the single exhaust and the extra 'secret' compartment in the trunk) and it sounds pretty good. Especially since it's a little 10, in a little enclosure, under a trap door in the floor of the trunk with a spare tire sitting on top of it (I don't run runflats anymore). So it's WAY better than stock, surprisingly good for what it is but I've been thinking about going infinite baffle too.... I only mention because there's something about our trunks that are good for sound. If my little muffled 10 sounds good, a corner box would sound great, and I'm thinking IB would be awesome whether or not you have trunk access from the cab and it's a good way not to take up so much room or add too much weight.

[mweisdorfer]

Originally Posted by E92inAZ

I'm old, I've been building car stereo systems since amps and crossovers were separate units and we were still running equalizers because head units only had bass and treble controls - if you were lucky!
Just for reference, I've got the bavsound uf110 in my car (made for e9x 328's with the single exhaust and the extra 'secret' compartment in the trunk) and it sounds pretty good. Especially since it's a little 10, in a little enclosure, under a trap door in the floor of the trunk with a spare tire sitting on top of it (I don't run runflats anymore). So it's WAY better than stock, surprisingly good for what it is but I've been thinking about going infinite baffle too.... I only mention because there's something about our trunks that are good for sound. If my little muffled 10 sounds good, a corner box would sound great, and I'm thinking IB would be awesome whether or not you have trunk access from the cab and it's a good way not to take up so much room or add too much weight.

My understanding is that if the subwoofer box is made of 100% fiberglass, it will sound better than one made of MDF.

[E92inAZ]

Originally Posted by mweisdorfer

My understanding is that if the subwoofer box is made of 100% fiberglass, it will sound better than one made of MDF.

I believe the sound waves don't care too much about material, rather, they interact with density of that material and the volume of air they're provided. Fiberglass can probably provide a nice firm enclosure for the speaker in more exotic shapes that your mdf would have trouble duplicating, but if you just built the same size plain square box to the manufacturer air volume specs out of each material you'd probably get the same result. Again, the caveat being that the fiberglass box would probably use less material and be lighter. And cooler, because anyone can build a box out of wood.

[Emilime75]

Pretty much what E92 said...

The strength and rigidity in a fiber glass enclosure comes from the compound shapes of its walls as it's molded to the trunk space...as long as it's made of sufficient layers/thickness and air bubbles are avoided during layup. These compound shapes also aid in eliminating standing waves within the enclosure, having the potential to sound better than a traditional, i.e. square box. That's about where the benefits of strength and sound quality end for fiberglass vs MDF/plywood. The same results could be had with wood if it is built right, braced sufficiently and made in an irregular shape, i.e. no parallel surfaces inside the box. Other benefits of FG over wood is that it's easier to mold the box to take advantage of all of the irregularities, nooks and crannies in the space you're trying to use to maximise internal volume, which would be difficult to do with wood. FG requires a different tool and skill set than wood, but it's certainly doable for any handy DIYer.

[shnaggs]

Just a quick update: ordered a IDmax 15, ended up getting a JL xd 600/1 for $175 on eBay, hope it works lol l. The sub is a 4 ohm dual VC, the amp is rated at 600w @ 2ohm. Question, it’s a mono amp but has 2 ch, or Left and Right...I guess. Can I just hook the one VC up to the one channel and the other to the other channel? I think that would make it 2 ohm’s to each VC?

[Emilime75]

Originally Posted by shnaggs

Just a quick update: ordered a IDmax 15, ended up getting a JL xd 600/1 for $175 on eBay, hope it works lol l. The sub is a 4 ohm dual VC, the amp is rated at 600w @ 2ohm. Question, it’s a mono amp but has 2 ch, or Left and Right...I guess. Can I just hook the one VC up to the one channel and the other to the other channel? I think that would make it 2 ohm’s to each VC?

That's a single channel amp with dual speaker terminals just for convenience when doing what you're doing...and, yes, the amp will see a 2 ohm nominal load and be able to produce 600w. It would be the same as wiring both coils in parallel to one set of speaker terminals.

[shnaggs]

Originally Posted by Emilime75

That's a single channel amp with dual speaker terminals just for convenience when doing what you're doing...and, yes, the amp will see a 2 ohm nominal load and be able to produce 600w. It would be the same as wiring both coils in parallel to one set of speaker terminals.

Sweet, thanks man!