Alpine type X 2020 or FI Q 15

[blazian87 10+ year member]

Yea you are right a folded horn is not the same size box, it does share the same response(12 db roll off) as a sealed, and t line. However the folded horn acomplishes this with a smaller box and is harder to design, that is why I paid PWK, who is now at AD Car audio and does designs there fyi.

The ultimo is decently loud, I did have 2510s running off .5 ohm so I believe I can claim this imo. Even tho there alot of subs that can get louder they have not won any awards for sq nor even have the reviews to compete. Show some respect

as for sealed being a step backwards, It is a matter of opinion but I believe the reason it sounds better to some people is the 12 db roll off on the low end (e.g. T line), ported extends much deeper while maintating spl and that can get boomy or reduce the perceived transient response. This is why woofers like JL w7, get that rep for being boomy.

Haha I feel what you're saying.. no disrespect to your ultimo and PWK. I was just saying loudness wise, it wouldn't be hard to accomplish. SQ part is subjective, I know.

I know what you're getting at about the 12 db roll off.. It is true.. sealed has a very smooth response and it can hit lower than a ported box even but the roll off starts early making the response get weaker and weaker as you go down. I care about that low end response a lot so my T-line is tuned down to my FS which is around 28hz so my roll off is very slow after that. You can imagine how deep my lows go. No subsonic filter either.. Very flat from top to bottom while having increased output all around.

 

[Radiospank 10+ year member]

Haha I feel what you're saying.. no disrespect to your ultimo and PWK. I was just saying loudness wise, it wouldn't be hard to accomplish. SQ part is subjective, I know.

I know what you're getting at about the 12 db roll off.. It is true.. sealed has a very smooth response and it can hit lower than a ported box even but the roll off starts early making the response get weaker and weaker as you go down. I care about that low end response a lot so my T-line is tuned down to my FS which is around 28hz so my roll off is very slow after that. You can imagine how deep my lows go. No subsonic filter either.. Very flat from top to bottom while having increased output all around.

I modeled the brahma and it did good up to 1000 watts sealed, more than enough for dual sub setup. I forgot to mention on why I want sealed and it's because of the lower group delay which imo does affect the sound where a ported or even horns, t lines can be slightly behind in phase. Give and take always with these things, so dual sub sealed it must be for me. I have to admit while the brahma is a solid choice, I am a sucker for aesthetics and good looking cones, so that's why i was considering JL w6, type X, fI, DD

 

[blazian87 10+ year member]

I modeled the brahma and it did good up to 1000 watts sealed, more than enough for dual sub setup. I forgot to mention on why I want sealed and it's because of the lower group delay which imo does affect the sound where a ported or even horns, t lines can be slightly behind in phase. Give and take always with these things, so dual sub sealed it must be for me. I have to admit while the brahma is a solid choice, I am a sucker for aesthetics and good looking cones, so that's why i was considering JL w6, type X, fI, DD

In that case, the type X does look attractive as well. I have only heard the old X sealed and they do sound really clean. If you're worried about phase, can't it be corrected with time alignment? I set my sub at 0 and then delay my speakers and I can't really tell that it's late anymore. I'm sure even sealed boxes have group delay but not as much as other boxes.

 

[Radiospank 10+ year member]

In that case, the type X does look attractive as well. I have only heard the old X sealed and they do sound really clean. If you're worried about phase, can't it be corrected with time alignment? I set my sub at 0 and then delay my speakers and I can't really tell that it's late anymore. I'm sure even sealed boxes have group delay but not as much as other boxes.

yes, i have my sub set the same way too, speakers are delayed and sub is 0ms. Depending on the box size, design, etc. the group delay can be significant at 40-20 hz, I think i've seen like 15ms or more.. its small but for me and some people it's noticeable.

 

[blazian87 10+ year member]

yes, i have my sub set the same way too, speakers are delayed and sub is 0ms. Depending on the box size, design, etc. the group delay can be significant at 40-20 hz, I think i've seen like 15ms or more.. its small but for me and some people it's noticeable.

hmm.. i see. That makes sense. I would imagine most of the group delay is near the tuning frequency of the port so wouldn't it almost be non-apparent if you tune low enough? Because I don't know if it will even be noticed at such a low frequency. I see where you're coming from tho. If you do go sealed, then go on the larger side for sure and try to aim for qtc .707 or lower if possible.

 

[blazian87 10+ year member]

So I have played with winISD a bit and see the big group delay in most ported alignments that you're talking about. It does look pretty significant. But don't forget that these graphs are before cabin reflections. Just by moving your enclosure more farther or closer can change your group delay. You turn your head 90 degrees and group delay is changing. I have heard that by EQing down the frequencies that are gained from the port can bring down group delay but then it would kinda defeat the purpose of going ported in the first place (more bass!). So right now the dual sub sealed box idea is looking like a good candidate since you have the power to back it up. I remembered when the guy (cscstang) built the T-line for me, he told me these enclosures are fast as hell, no lag. Since my box is a quarter wave length design, it's very straight and flat so they don't have a chance to lag behind. The sub goes straight into an equal length tube and out instantly through the port without any place to resonate like you see in a typical box. I pitched him the idea what would happen if I extend the port going sideways after it ends? He said it would just lower the tune. So he used that idea to create my enclosure except that it went all the way to where the sub meets. He reached out to keep_hope_alive, which is an acoustical engineer, and asked him if this was a good idea. KHA said this is actually ideal because the front wave and back wave are reaching each other at the same time and they come out together. Cscstang demo'ed me my first true T-line experience in his truck that had 2 15's in this ginormous T-line. He played a variety of music for me and one of them was this fast ass double bass pedal metal song and it had absolutely no problem keeping up while being incredibly loud. What impressed me the most tho was that he was able to switch up to any genre of music and be able to hit every damn note at full blast like no tomorrow.

 

[Radiospank 10+ year member]

So I have played with winISD a bit and see the big group delay in most ported alignments that you're talking about. It does look pretty significant. But don't forget that these graphs are before cabin reflections. Just by moving your enclosure more farther or closer can change your group delay. You turn your head 90 degrees and group delay is changing. I have heard that by EQing down the frequencies that are gained from the port can bring down group delay but then it would kinda defeat the purpose of going ported in the first place (more bass!). So right now the dual sub sealed box idea is looking like a good candidate since you have the power to back it up. I remembered when the guy (cscstang) built the T-line for me, he told me these enclosures are fast as hell, no lag. Since my box is a quarter wave length design, it's very straight and flat so they don't have a chance to lag behind. The sub goes straight into an equal length tube and out instantly through the port without any place to resonate like you see in a typical box. I pitched him the idea what would happen if I extend the port going sideways after it ends? He said it would just lower the tune. So he used that idea to create my enclosure except that it went all the way to where the sub meets. He reached out to keep_hope_alive, which is an acoustical engineer, and asked him if this was a good idea. KHA said this is actually ideal because the front wave and back wave are reaching each other at the same time and they come out together. Cscstang demo'ed me my first true T-line experience in his truck that had 2 15's in this ginormous T-line. He played a variety of music for me and one of them was this fast ass double bass pedal metal song and it had absolutely no problem keeping up while being incredibly loud. What impressed me the most tho was that he was able to switch up to any genre of music and be able to hit every damn note at full blast like no tomorrow.

Well a tline sounds like a good project for sq, but I want some more output and since I have a horn enclosure already, building a T line wouldn't be enough output for me. I certainly can't build a t line for 2 12's or even 2 10's due to space, trying to keep it limited in box size. The thought of a clean t line sounds nice but sealed should get the job done for SQL build.

 

[blazian87 10+ year member]

Well a tline sounds like a good project for sq, but I want some more output and since I have a horn enclosure already, building a T line wouldn't be enough output for me. I certainly can't build a t line for 2 12's or even 2 10's due to space, trying to keep it limited in box size. The thought of a clean t line sounds nice but sealed should get the job done for SQL build.

yeah t-line would just take up too much space I totally understand.. I think 2 subs at 1 ohm sounds promising. You should be able to easily get louder than what you have.

 

[Radiospank 10+ year member]

DD subs <-----------heres a pic of my dual 10s, took up the whole trunk.