AVS Forum banner

2581 - 2600 of 5119 Posts

·
Registered
Joined
·
19,282 Posts
Yes, that is why I use 95.3 for the SI, that is what it sims. If you look at the max spl charts from Ricci it is very close to that. The sims don't take the distortion and box size into account from Ricci. When I sim I use .707 for all sealed systems to equalize the sims. Ricci recorded 89.2 for a distortion burst test, the sim is closer to the max spl chart ricci has and using the SI vs the FiQ18 confirms this. Basicaly, the SI has a passing test at 10hz where the Q18 did not. However, the max spl chart shows an advantage at 10hz for the Q18 and that is what the sim predicts.
 

·
Registered
Joined
·
19,282 Posts
If he did it by actual in-room measurements I'd be at 5* at 10hz ;)

I am not using in room, WinIsd models.
If I used in room I would gain over 30 dBs at 5hz! I ported this low because of my massive room gain and signal chain. I guess I am confused but most have been correct doing it your way. This is your thread, I am just saying how I always estimated everyone's setup.
 

·
Registered
Joined
·
10,479 Posts
I am not using in room, WinIsd models.
If I used in room I would gain over 30 dBs at 5hz! I ported this low because of my massive room gain and signal chain. I guess I am confused but most have been correct doing it your way. This is your thread, I am just saying how I always estimated everyone's setup.
Sorry, think I misread, was reading too quickly.
 

·
Registered
Joined
·
19,282 Posts
No problem. No matter which way you convert the data it should be the same. The Fi IB3-18 is 1.5 Si or 3 dBs more at 10hz if I remember correctly. It was 99 dBs at 10hz and the Si was 95.3 dBs from the sims. That of course was using a 60 cubic foot enclosure for sim. I had only 28 cubes per driver which made the roll off 3 dBs more and you can't just boost the low end of this driver, not enough motor. Basically it acted like 8 SI sealed rather than the 12 SI. This new setup acts like a whole new room.
 

·
Registered
Joined
·
19,282 Posts
Dom, no matter which way you convert I should be 33 dBs or more over 1 Si at 5hz. I am close to 50 SI either way at 5hz. This is assuming you have the power to drive it to it's fullest.
1= 83 dBs
2= 89 dBs
4= 95 dBs
8= 101 dBs
16=107 dBs
32=113 dBs(I have 115-116 dBs from the front wall and 3 dBs more would be half of 32 or 16 more which equals 48 drivers), then add the 4 drivers in back(about another 1.5 dBs)
64=119 dBs
 

·
Registered
Joined
·
3,349 Posts
Discussion Starter #2,586

On your sim above, 5hz shows a little more than 96db. Subtract 12 to get to 1 SI. This puts it at 84db and change.

Your ported sub in the sim above shows 115db at 5hz. That is a 31db difference.

The issue here with your logic is that you cannot use 115db as your 5hz output. Based on the way I've been calculating everything else, you need to add the difference between the SI sim and the ported sim (31db) and add that to the SI db at databass. Now, josh didn't test the SI at 5hz, but he did at 10hz where it achieved 89.2db. If we assume a 12db rolloff for sealed alignments, that puts it at 77.2db at 5hz.

Add 31db to 77db, and you get 108db at 5hz. A 108db and 115db translate into different SI equivalents, and are obviously not the same. Add you 4 other SI in at 5hz, and you pickup a db to 109. This translates to 39.5si.

I have not used the db produced directly from the sims on any of the estimates thus far. Right or wrong, I have to stay consistent.
 

·
Registered
Joined
·
19,282 Posts
Well I have always used 83 since that is the .707 box and SPL of the SI. My box is at 84, because I made it that way. Although it is an SI it is slightly more with my box. It does not matter with one but with 32 another 1.5 dBs is 8 more SI's! So from 83 to 113 is 32 and 2 more dB's would be at least 8 more SI or 40. Then add the 4 SI in the rear for 44. My 6hz is 52 Si though all for lone survivor! It is probably more because I did not get 12 dBs more at 6hz like the sim, I am getting 13 dBs more. Those precious dBs. I am nit picking here so do what you want. Either way you need to hear this! Remember, this setup was your approval!
 

·
Premium Member
Joined
·
2,586 Posts
JP,
I started the 5hz as I just finished my new build with ULF focus.
Your ULF score is the same as your 10hz score since you are all sealed. If you look at the member list on post 2, you'll see who has 5 hz scores (you are on there). In the next update, I'll have the template where you can create your 5hz card, but it's all manual, meaning it would be a cut and paste thing.

I haven't included 5hz in the calculator yet because to achieve a score here, you have to have the right signal chain and post your response to 5hz. I'm guessing most do not have signal chains that are flat to 5hz, and so don't include it automatically.

Would love to get a demo of your theater...probably one of the best ht experiences there is!
OK, I got you now. I am good to 3hz with signal chain roll-off I believe. Well that is where I start to roll off in REW.
 

·
Registered
Joined
·
19,282 Posts
JP,
Do you have an uneq'd and no low boost of your system? You are using the Datasat processor? I think I remember you having re real Lab's, correct? You have the best 18's IMHO. Which do you like better? LMS or XXX?
 

·
Registered
Joined
·
3,349 Posts
Discussion Starter #2,590
Well I have always used 83 since that is the .707 box and SPL of the SI. My box is at 84, because I made it that way. Although it is an SI it is slightly more with my box. It does not matter with one but with 32 another 1.5 dBs is 8 more SI's! So from 83 to 113 is 32 and 2 more dB's would be at least 8 more SI or 40. Then add the 4 SI in the rear for 44. My 6hz is 52 Si though all for lone survivor! It is probably more because I did not get 12 dBs more at 6hz like the sim, I am getting 13 dBs more. Those precious dBs. I am nit picking here so do what you want. Either way you need to hear this! Remember, this setup was your approval!
Yes, I agree with this. Didn't realize your box increased the si by 1db. 83 should be the number at 5hz as you mentioned.

I will recalculate when I get back, but I think 44 to 50 is going to be the right range.

Question though: box size is irrelevant with enough power when it comes to max output, correct? In other words, if Josh used your size box, it would not change the max output of the si.

The extra db you show only exists in the sim as in reality it could be never more than what Josh tested?
 

·
Registered
Joined
·
19,282 Posts
Correct, The extra dB is a sensitivity thing and I need less power and less boost down low. It does not matter as now I don't need any boost as the port adds the shelf itself until signal rolls off. The best part is the peak is in the feel range so it has no audible effects. I just added the new mono blocks,Yamaha Aventage receiver as a processor and I can actually ditch the NanoAvr with this. It sounds incredible and just the Balrog scene was like a 5 star movie. This will get me in trouble for sure. I am going to break more crap.
 

·
Premium Member
Joined
·
2,586 Posts
JP,
Do you have an uneq'd and no low boost of your system? You are using the Datasat processor? I think I remember you having re real Lab's, correct? You have the best 18's IMHO. Which do you like better? LMS or XXX?
Yes I have the real Lab Gruppen amps.
I like the XXX personally, but that just may be b/c I have them in an IB setup. I would have to compare them apples to apples style to make a fair judgment.

The below graph is no Eq applied sweep.



And this is the EQ with the house curve.

 

·
Premium Member
Joined
·
2,586 Posts
XXX vs LMS, if you want to dig real deep, XXX kills it. The LMS can't keep up with the excursion. However, the LMS does better elsewhere and at higher frequencies. Depends what you're building. When I was tuning around 15hz, I couldn't find anything that modeled better.
Agreed , you need the numbers with the XXX. 2 x RE XXX will dig real deep but will leave you lacking above about 60hz. I can't remember, but when I was teseting 4 x RE XXX drivers I was just getting enough to stay flat to about 75-80hz, after that was not very good at all. The LMS will go way past that.
 

·
Registered
Joined
·
19,282 Posts
I figured that much, the XXX is really an IB driver anyways! IB drivers tend to not have the upper end like the LMS 5400.

Notnyt,
I am sure the LMS does just fine sealed and still one of the best! If you had my small room you would still be running your sealed subs and at 140 dBs rather than 130 dBs! You just have a massive room which is great for acoustics so you win there.

JP,
Your -5 dB point is 3 hz, how do you like the house curve compared to without?
 

·
Premium Member
Joined
·
2,586 Posts
I figured that much, the XXX is really an IB driver anyways! IB drivers tend to not have the upper end like the LMS 5400.

Notnyt,
I am sure the LMS does just fine sealed and still one of the best! If you had my small room you would still be running your sealed subs and at 140 dBs rather than 130 dBs! You just have a massive room which is great for acoustics so you win there.

JP,
Your -5 dB point is 3 hz, how do you like the house curve compared to without?
The house curve is so much better than a flat response, it really is that noticeable.
 
  • Like
Reactions: Fatshaft
2581 - 2600 of 5119 Posts
Top