gene's speakers - cabinet tuning, crossover and more!

[gene]

Thank you don mascali very much for your help and your time to drive to my house - gas is not cheap. and hook up your eq, and give me your input and knolwledge. Its a big start in the right direction. thank you gene

[boputnam]

Hey, now that's pretty cool!!

So, Don - what did you find?

[Robh3606]

Oh Good

Glad to hear someone made it over there with some gear.

Rob

[Zilch]

So, Don - what did you find?

Yeah, Don.

We NEED to know!!!

[gene]

I spoke to don last night, he told me he was going to respond to your question. what he told me, the cabinet maker did a damm good job he knew what he was doing. I guess we will have to wait on don to tell us what he found

[gene]

I guess don is busy. what he found the 2202h housing is .8 cubic ft, inside measurements of the cab, take the midrange housing and bracing 12 -1/2 cubic ft. he brought his own music to compare the sound of my system to his. he had the bass and treble set at the half way mark. 12 oclock there was plenty of bass. he use some kind of spectuim analiyzer with a micphone ,my 2425h was a little high compare to the rest of the drivers at the same db level. he said who ever built my cabs knew what the hell there were doing.the cab is tune kind of low . jbl speakers are tuned around 30hz , maybe I should have the my speaker tuned around 30hz and biamp my speakers. he also said the bracing insde the cabs were well done

[Ian Mackenzie]

Gene,

None of this is an exact science.

The tuning of your boxes is based on a simulated model using certain assumtpions. As such the current tuning is only accurate for those assumptions which may or may not be the case in reality.

Ideally, a box can be tuned (within realms of a proper alignment, not a misalignment) for a particular room situation / roomboundary/box location.

Ultimately only you can decide what is satisfactory.

Ian

[Don Mascali]

Sorry for the delay, real life has been a PIA. I will go into detail a little later.

[gene]

hello Ian. I want to change my tunning on my speakers. music bass playback or record on cd is about 30 to 60 hz. I have bass when I play my music.but when I play my dvds the walls-ceiling is rockin. there is a difference in sound quailty. I want the same repsonce out of my music as I do when I play my dvds I also want to biamp my speakers.Don was a lot of help. when I spend that much money on a set of speakers that I know can kick ass I wont stop until I have them right. If I have to wait until I have the money or beg please barrow etc.I will get them square away. don is a big help I cant thank him enough. in this crazy world we live in- don didnt know me from apples to oranges plus gas is high and time is money. thanks agin don if there any thing I can do for you let me know -you wont have to ask me twice. LONG LIVE JBL

[Don Mascali]

Box construction;
54” x 29” x 19” outside, so 14.62 ft3 internal volume, minus 0.8 cu ft for the 2206H dog house, (0.53 ft3 internal). The construction was good of birch veneer cabinet grade plywood and reasonably braced. I would make the net volume at 13.5 ft3

Box tuning;
I wasn’t able to determine the box tuning frequency with a signal generator and cone motion. I had a WT2 with me but there wasn’t a computer in the room that we could use. Gene has to have one of his 2245Hs reconed, so I will bring a laptop back to test them both up when He gets it done. My best guess is that the box is tuned a bit low with a gentle roll off and is good candidate for a bump filter. Gene is still climbing the learning curve and this might be a problem for him at this time, as would a bi-amp set up. For all but a few of us hardcore knob tweekers, it can cause more trouble than benefits. He has some nice old high end Technics gear with a dual 31 band EQ and an analyzer. It also has some nice bass shaping controls on the pre-amp and he has a Stasis amp that seems to be up to the job but certainly could use some help.
We did some education on the nature of the “Bass” he was looking for (Thanks to Carlos Santana’s “Supernatral” percussion). We think that a higher tuning would be appropriate at this time and drop it down when he catches up on equipment and expertice.

Room;
We set up the Behringer 61 band RTA and test mike and looked at some pink noise. The room is short on the speaker to listener distance and wide with no wall on the left side. The left was the only speaker we tested so there was very little help from room gain. The speaker was up to the task when we gave it some thump to work on. And played with the controls. We found a severe 40 hz null in the room center and it is at about 45 hz at the preferred listening position (About 6-8 feet, so it’s almost nearfield conditions) We also found some reinforcement at about 100 to 150hz that made the 2206H LMF sound a little too hot and therefore the whole system sounded “bass shy” in comparison. With no L-pads on the speakers we may have to dial it in with the EQ later.

I enjoyed meeting with Gene and found we work in the same industry. He’s a nice guy, and was frustrated that I don’t drink, so that he could make me feel more at home.
We have some work to do but I think he’s got a great set of speakers to play with and it is up to us to understand the fine points of care and feeding them.

More shall be revealed.

Here is Gene, He's a big guy.

[Zilch]

Here is Gene, He's a big guy.

Yeah, well, his speakers are pretty big, too!

VERY nice, Gene....

Thank you, Don, for helping with Gene's system.

[boputnam]

We have some work to do but I think he’s got a great set of speakers to play with and it is up to us to understand the fine points of care and feeding them.

More shall be revealed.

Great effort, Don. Interesting the null(s) you found in the room.

Gene standing next to those speakers makes them look like small near-field monitors!

[Ian Mackenzie]

Don and Gene,

Very nice post and picture.

Gene, I think it would be wise to wait until you have reconed your other woofer before considering updating the tuning.

Until then enjoy.

Ian

p.s My in box is full and will be closed until I work out what to do with all those pms.

[johnaec]

p.s My in box is full and will be closed until I work out what to do with all those pms.

You do know that you can download PM messages, (function at bottom of PM page), then delete them from your PM's.

John

[Ian Mackenzie]

Well I think it is great someone from The Lansing Forums managed to see you Gene.

All this takes time. Sometimes its the journey that counts.

But with JBL's the results are really worth it.

Ian