Greetings
I have all the spare drivers and crossovers for the JBL,L7 speakers but I do not have the L7 enclosure. I bought a pair of smaller enclosures from Goodwill for cheep, the boxes date way back to the 1975 and are solid built ,measures 27x16x10.5 inchs.
I do not know anything about building speakers so if you can advise on what all needs to be done.
Laying the box down and setting the speakers on the new front panel all the four drivers will fit .
Does this enclosure need to be vented and what size and lenght the tube needs to be?
Do I need to brace the front panel and use damping material ?
Any advise on building this speaker would be appreciated.
Thank you in advance
Bob
I have all the spare drivers and crossovers for the JBL,L7 speakers but I do not have the L7 enclosure. I bought a pair of smaller enclosures from Goodwill for cheep, the boxes date way back to the 1975 and are solid built ,measures 27x16x10.5 inchs.
I do not know anything about building speakers so if you can advise on what all needs to be done.
Laying the box down and setting the speakers on the new front panel all the four drivers will fit .
Does this enclosure need to be vented and what size and lenght the tube needs to be?
Do I need to brace the front panel and use damping material ?
Any advise on building this speaker would be appreciated.
Thank you in advance
Bob
Attachments
Some inspiration: L7 Breakup
The 8" driver can really go deep in frequency, so you can turn it into a satellite+sub(s) system.
By the way, not not put those drivers on their face like in your photo: the surrounds are protuberant, and quite fragile...
The 8" driver can really go deep in frequency, so you can turn it into a satellite+sub(s) system.
By the way, not not put those drivers on their face like in your photo: the surrounds are protuberant, and quite fragile...
Thank you for the link about the information on the JBL,L7, yours is beautiful and a great idea, but I am not very good with woodworking and do not have any woodworking equipment to build anything like that.
I will have to continue with what I started out with, the woodworking of the old boxes are not bad and I think I can make a decent looking speaker much the same as the JBL L100
[SIZE=+0]JBL,L100 which is Width[/SIZE] [SIZE=+0]14.6 in.[/SIZE] [SIZE=+0]Depth[/SIZE] [SIZE=+0]13.8 in.[/SIZE] [SIZE=+0]Height[/SIZE] [SIZE=+0]23.6 in.[/SIZE]
My L7 to JBL L100 project measures 16x10.5 x27 inchs.
I will have to continue with what I started out with, the woodworking of the old boxes are not bad and I think I can make a decent looking speaker much the same as the JBL L100
[SIZE=+0]JBL,L100 which is Width[/SIZE] [SIZE=+0]14.6 in.[/SIZE] [SIZE=+0]Depth[/SIZE] [SIZE=+0]13.8 in.[/SIZE] [SIZE=+0]Height[/SIZE] [SIZE=+0]23.6 in.[/SIZE]
My L7 to JBL L100 project measures 16x10.5 x27 inchs.
That's is not my speaker 😉 (I have zero woodworking skills for that matter)
What you could do is put the three upper drivers in that small box, and find other boxes for the 12"...
What you could do is put the three upper drivers in that small box, and find other boxes for the 12"...
Bob-
May I ask you to look on the XO boards and see if there are any switches or jumpers? I read elsewhere on the net that you could adjust slopes on the XO via switches/jumpers however being INSIDE the enclosure I am hesitant to open it up and check.
Thanks,
May I ask you to look on the XO boards and see if there are any switches or jumpers? I read elsewhere on the net that you could adjust slopes on the XO via switches/jumpers however being INSIDE the enclosure I am hesitant to open it up and check.
Thanks,
Definition of PROTUBERANT
: thrusting out from a surrounding or adjacent surface often as a rounded mass : prominent <protuberant eyes>
— pro·tu·ber·ant·ly adverb
I had to look it up to triple check before I replied... 😀
Aren't MOST drivers protuberant?
Also the midrange and midbass are rubber so unless the rubber has dried out they should be quite resilient.
The tweeter mesh could be pushed in and the foam on the woofer may get torn up but I still wouldn't call either "fragile."
Just my OPINION. Yours may vary and we all have a right to one. Or three. 🙄
Sorry, this is a common word in french so I though it was also quite common in english. Prominent would have been a better word.
Anyway, those surround do go way past the frame, unlike most drivers, and are very fragile. These are made in a really soft foam (or rubber? I don't know), as is the soft dustcap.
Those are very different from other JBL drivers, and are probably made by audax.
Anyway, those surround do go way past the frame, unlike most drivers, and are very fragile. These are made in a really soft foam (or rubber? I don't know), as is the soft dustcap.
Those are very different from other JBL drivers, and are probably made by audax.
Crossover L7
Greetings
There is a blue jumper wire factory set to Common/Normal and can be changed to Common/ Bi-amp ,once the blue wire jumper is changed to Common/Bi-amp, that will bi-pass the filter capacitor C1 [170uF] and C2 which is .01uF. Once the blue jumper is changed, the signal for the woofer travels from the amp through a 8.9Mh coil to the LE120-H woofer .
Bob
Greetings
There is a blue jumper wire factory set to Common/Normal and can be changed to Common/ Bi-amp ,once the blue wire jumper is changed to Common/Bi-amp, that will bi-pass the filter capacitor C1 [170uF] and C2 which is .01uF. Once the blue jumper is changed, the signal for the woofer travels from the amp through a 8.9Mh coil to the LE120-H woofer .
Bob
Attachments
Hmmm.. Either your enclosures are different or something is amiss.
The ones here have 2 pairs of binding posts on the back for bi-amping, it is not an internal jumper. But the 12" has a passive low pass in line always and the 8" has a passive bandpass in line always regardless of whether it is one amp or two.
I would bet that the Blue jumper is to bypass the C1 cap making the 8 inch passively high passed only so you could use an active XO to split the top section from the bottom.
I wrote JBL today to see what the jumper was for if they have a record for it.
and a HUGE thanks for the picture.. It is worth more that a thousand words in this case.
The ones here have 2 pairs of binding posts on the back for bi-amping, it is not an internal jumper. But the 12" has a passive low pass in line always and the 8" has a passive bandpass in line always regardless of whether it is one amp or two.
I would bet that the Blue jumper is to bypass the C1 cap making the 8 inch passively high passed only so you could use an active XO to split the top section from the bottom.
I wrote JBL today to see what the jumper was for if they have a record for it.
and a HUGE thanks for the picture.. It is worth more that a thousand words in this case.
L7
Actually, I have placed the one with the blue jumper that has binding posts on the under side of it that are hidden from view and I placed it beside the hi frequency crossovers, just to take the picture .
The crossovers are out of the L7, and are placed in a different box, a new project under way.
I bought a brand new pair of L7's new many years ago and later in 2011,I bought a complete set of drivers and crossovers just for spare.
Actually, I have placed the one with the blue jumper that has binding posts on the under side of it that are hidden from view and I placed it beside the hi frequency crossovers, just to take the picture .
The crossovers are out of the L7, and are placed in a different box, a new project under way.
I bought a brand new pair of L7's new many years ago and later in 2011,I bought a complete set of drivers and crossovers just for spare.
Attachments
From the schematic that blue jumper changes the low pass to the 12" from a 12db filter to a single pole 6db filter.
Hi Troy,
There are no switches on the L7 crossover that will change any of the tonal response. If I remember correctly, very early on in production, there was an internal switch that had to be flipped if you were going to be bi-amping, as well as removing the bridging straps.
I hope this helps.
Joe C......
Technical Support
Harman Lifestyle Division
There are no switches on the L7 crossover that will change any of the tonal response. If I remember correctly, very early on in production, there was an internal switch that had to be flipped if you were going to be bi-amping, as well as removing the bridging straps.
I hope this helps.
Joe C......
Technical Support
Harman Lifestyle Division
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