JBL 308P and 708P

We use the Tune Method to evaluate performance

Moderator: Staff

User avatar
jajo
Active member
Active member
Posts: 213
Joined: 2007-01-19 15:08
Location: Sweden
Contact:

Re: JBL 308P and 708P

Post by jajo »

Discodave wrote: 2022-01-19 17:14 Many thanks Defender. I had no intention of changing but was very curious as to why Jajo had.
I haven't. I adjusted the gain to -4.5dB because of the corner.
Discodave
Very active member
Very active member
Posts: 349
Joined: 2017-05-18 14:50
Location: Belfast, Ireland

Re: JBL 308P and 708P

Post by Discodave »

Ah, so just a volume change. What difference did it make to the corner situation? Ta
LP12, Lingo 3, Cirkus/Kore, Tramp 2, Basik Plus Ania, Linto
Majik Ds, Kisto, Tundra 2.0, Majik 109
User avatar
ThomasOK
Very active member
Very active member
Posts: 4358
Joined: 2007-02-02 18:41
Location: United States
Contact:

Re: JBL 308P and 708P

Post by ThomasOK »

A little while back there was a question or two about the passive version that needs an external electronic crossover and amps. Although I'm sure it would be very cool if Fredrik came out with an electronic crossover for it I wouldn't hold my breath. The complexity of building an electronic crossover and the need to make it specifically for the 708 would argue against the economic sense and spending the effort on such a device. Making is general purpose device would require much more complexity and might not allow the kind of perfromance Fredrik achieves with all of his products.

However, there is a possibility if some brave soul wants to try it. The Marchand XM44 crossover I used with my JBL 3677/4645C setup as a subwoofer crossover is available in 1, 2, 3 or 4 way versions a section of which can be for a subwoofer with summing if desired. While I don't expect it would be near Lejonklou level I was quite happy with it for my subwoofer as were several other people who bought them from me for the same purpose. It also has some interesting advantages that might make it suitable for the 708s where other crossovers might not be. First you can order the crossover points at any frequency from 20Hz to 20kHz, then you can order any slope from 6dB to 48dB per octave in 6dB increments. They can also be asymmetric if needed. But that is just the frequencies. Each section has three card slots which allow for other options such as notch filters, delay sections, baffle step compensation, etc. So if you can find out the exact crossover specs from the 708P it is highly likely Phil Marchand can duplicate them. The pots for volume adjustment are stepped attenuators are normally 1dB per step but can be ordered as .5dB per step for an additional charge. The prices are also pretty reasonable. Here is a link for the model I used and a US price list is also on the website.

https://www.marchandelec.com/xm44-elect ... sover.html

It at least seems like it might be an option, but that depends on how complex JBL made the crossover and what they did in it.
The LP12 Whisperer
Manufacturer, Distributor, Retailer and above all lover of music.
User avatar
jajo
Active member
Active member
Posts: 213
Joined: 2007-01-19 15:08
Location: Sweden
Contact:

Re: JBL 308P and 708P

Post by jajo »

ThomasOK wrote: 2022-01-19 23:28 A little while back there was a question or two about the passive version that needs an external electronic crossover and amps. Although I'm sure it would be very cool if Fredrik came out with an electronic crossover for it I wouldn't hold my breath. The complexity of building an electronic crossover and the need to make it specifically for the 708 would argue against the economic sense and spending the effort on such a device. Making is general purpose device would require much more complexity and might not allow the kind of perfromance Fredrik achieves with all of his products.

However, there is a possibility if some brave soul wants to try it. The Marchand XM44 crossover I used with my JBL 3677/4645C setup as a subwoofer crossover is available in 1, 2, 3 or 4 way versions a section of which can be for a subwoofer with summing if desired. While I don't expect it would be near Lejonklou level I was quite happy with it for my subwoofer as were several other people who bought them from me for the same purpose. It also has some interesting advantages that might make it suitable for the 708s where other crossovers might not be. First you can order the crossover points at any frequency from 20Hz to 20kHz, then you can order any slope from 6dB to 48dB per octave in 6dB increments. They can also be asymmetric if needed. But that is just the frequencies. Each section has three card slots which allow for other options such as notch filters, delay sections, baffle step compensation, etc. So if you can find out the exact crossover specs from the 708P it is highly likely Phil Marchand can duplicate them. The pots for volume adjustment are stepped attenuators are normally 1dB per step but can be ordered as .5dB per step for an additional charge. The prices are also pretty reasonable. Here is a link for the model I used and a US price list is also on the website.

https://www.marchandelec.com/xm44-elect ... sover.html

It at least seems like it might be an option, but that depends on how complex JBL made the crossover and what they did in it.
One interesting thing with 708I is that maybe JBLs filter settings are not the most musical. With a variable filter, it might be possible to tweak them to perfection.
Lego
Very active member
Very active member
Posts: 1147
Joined: 2007-04-18 11:42
Location: glasgow

Re: JBL 308P and 708P

Post by Lego »

This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
I know that tune
User avatar
Tendaberry
Very active member
Very active member
Posts: 982
Joined: 2010-08-30 16:08
Location: Hamburg

Re: JBL 308P and 708P

Post by Tendaberry »

Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
That's an interesting link: for € 149,- my IKEA Symfonisk Picture Frame seems to be doing quite well ;-)
https://pierreaubert.github.io/spinoram ... ture+Frame
Lego
Very active member
Very active member
Posts: 1147
Joined: 2007-04-18 11:42
Location: glasgow

Re: JBL 308P and 708P

Post by Lego »

Tendaberry wrote: 2022-01-20 17:03
Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
That's an interesting link: for € 149,- my IKEA Symfonisk Picture Frame seems to be doing quite well ;-)
https://pierreaubert.github.io/spinoram ... ture+Frame
Indeed,which reminds me did you manage any skiing this season Tendaberry :0)

Your picture frame cost the same as my jbls,which is nice.
I know that tune
Defender
Very active member
Very active member
Posts: 1266
Joined: 2018-02-14 22:35

Re: JBL 308P and 708P

Post by Defender »

Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
I dont give much to those measurements but if I would I would say the 308 got too good so it might be cannibalized the more expensive lines so JBL rather optimized that and came out with the 308 MKII
Azazello
Very active member
Very active member
Posts: 630
Joined: 2007-01-30 21:59
Location: Stockholm, Sweden

Re: JBL 308P and 708P

Post by Azazello »

Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
Have a look at the curve of the M2 😳
maffe
Very active member
Very active member
Posts: 300
Joined: 2016-02-14 20:05

Re: JBL 308P and 708P

Post by maffe »

Azazello wrote: 2022-01-20 22:32
Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
Have a look at the curve of the M2 😳
V-fib?!?
Lego
Very active member
Very active member
Posts: 1147
Joined: 2007-04-18 11:42
Location: glasgow

Re: JBL 308P and 708P

Post by Lego »

Azazello wrote: 2022-01-20 22:32
Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
Have a look at the curve of the M2 😳
Yes saw that ...those pesky amps 😁
I know that tune
Lego
Very active member
Very active member
Posts: 1147
Joined: 2007-04-18 11:42
Location: glasgow

Re: JBL 308P and 708P

Post by Lego »

Defender wrote: 2022-01-20 22:12
Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
I dont give much to those measurements but if I would I would say the 308 got too good so it might be cannibalized the more expensive lines so JBL rather optimized that and came out with the 308 MKII
That's a very nice conspiracy theory Defender 🤠
I know that tune
tokenbrit
Very active member
Very active member
Posts: 2038
Joined: 2012-03-22 19:47
Location: New England

Re: JBL 308P and 708P

Post by tokenbrit »

Maybe my imagination but LSR308 looks better than 708P ... The Price is Right, certainly, or would you like to spin again?
User avatar
jajo
Active member
Active member
Posts: 213
Joined: 2007-01-19 15:08
Location: Sweden
Contact:

Re: JBL 308P and 708P

Post by jajo »

tokenbrit wrote: 2022-01-21 01:25 Maybe my imagination but LSR308 looks better than 708P ... The Price is Right, certainly, or would you like to spin again?
They do look different. 308P looks/feels cheaper but less "boxy" and "PRO". I like them both but prefer the CF driver and bass driver of 708P. And the weight.
tokenbrit
Very active member
Very active member
Posts: 2038
Joined: 2012-03-22 19:47
Location: New England

Re: JBL 308P and 708P

Post by tokenbrit »

jajo wrote: 2022-01-21 04:24
tokenbrit wrote: 2022-01-21 01:25 Maybe my imagination but LSR308 looks better than 708P ... The Price is Right, certainly, or would you like to spin again?
They do look different. 308P looks/feels cheaper but less "boxy" and "PRO". I like them both but prefer the CF driver and bass driver of 708P. And the weight.
I was referring to the SPINorama traces for LSR308 & 708P - fun, but made me wonder how much you can/should read into the measurements...
Lego
Very active member
Very active member
Posts: 1147
Joined: 2007-04-18 11:42
Location: glasgow

Re: JBL 308P and 708P

Post by Lego »

tokenbrit wrote: 2022-01-21 05:03
jajo wrote: 2022-01-21 04:24
tokenbrit wrote: 2022-01-21 01:25 Maybe my imagination but LSR308 looks better than 708P ... The Price is Right, certainly, or would you like to spin again?
They do look different. 308P looks/feels cheaper but less "boxy" and "PRO". I like them both but prefer the CF driver and bass driver of 708P. And the weight.
I was referring to the SPINorama traces for LSR308 & 708P - fun, but made me wonder how much you can/should read into the measurements...
I've only heard 2 speakers on there, the 308s and the Kef reference 5s .The Kefs sounded terrible and maybe it's a coincidence they measured badly.Different setup and track,not ideal but here's Reference 5

https://drive.google.com/file/d/14Ibb-b ... p=drivesdk

JBL 308s.

https://drive.google.com/file/d/1U391uI ... p=drivesdk
I know that tune
Ianw
Active member
Active member
Posts: 148
Joined: 2019-02-22 11:09

Re: JBL 308P and 708P

Post by Ianw »

Down the “dunny” in L&C Skunk Works.

LOL
Azazello
Very active member
Very active member
Posts: 630
Joined: 2007-01-30 21:59
Location: Stockholm, Sweden

Re: JBL 308P and 708P

Post by Azazello »

maffe wrote: 2022-01-20 22:41 V-fib?!?
Look att the deep bass. I want them.
Last edited by Azazello on 2022-01-21 10:56, edited 1 time in total.
User avatar
Tendaberry
Very active member
Very active member
Posts: 982
Joined: 2010-08-30 16:08
Location: Hamburg

Re: JBL 308P and 708P

Post by Tendaberry »

Lego wrote: 2022-01-21 07:24 I've only heard 2 speakers on there, the 308s and the Kef reference 5s .The Kefs sounded terrible and maybe it's a coincidence they measured badly.Different setup and track,not ideal but here's Reference 5

https://drive.google.com/file/d/14Ibb-b ... p=drivesdk

JBL 308s.

https://drive.google.com/file/d/1U391uI ... p=drivesdk
Well, my foot started tapping to the 308's, not to the KEF's though. Easy choice...
Spannko
Very active member
Very active member
Posts: 2292
Joined: 2008-01-24 21:46
Location: North East of The Black Country, UK

Re: JBL 308P and 708P

Post by Spannko »

maffe wrote: 2022-01-20 22:41
Azazello wrote: 2022-01-20 22:32
Lego wrote: 2022-01-20 15:39 This is Spinorama data for JBL308 vs JBL 308 mark IIs

Seems to concur with Jajo's impressions


https://pierreaubert.github.io/spinoram ... 8P+Mark+ii
Have a look at the curve of the M2 😳
V-fib?!?
Ventricular fibrillation?
Lego
Very active member
Very active member
Posts: 1147
Joined: 2007-04-18 11:42
Location: glasgow

Re: JBL 308P and 708P

Post by Lego »

Spannko wrote: 2022-01-21 12:52
maffe wrote: 2022-01-20 22:41
Azazello wrote: 2022-01-20 22:32

Have a look at the curve of the M2 😳
V-fib?!?
Ventricular fibrillation?
That what I was thinking 😂
I know that tune
maffe
Very active member
Very active member
Posts: 300
Joined: 2016-02-14 20:05

Re: JBL 308P and 708P

Post by maffe »

Lego wrote: 2022-01-21 13:49
Spannko wrote: 2022-01-21 12:52
maffe wrote: 2022-01-20 22:41

V-fib?!?
Congrats✨?
That what I was thinking 😂
Can we agree on it looking Ventricular fibrillation :P
Defender
Very active member
Very active member
Posts: 1266
Joined: 2018-02-14 22:35

Re: JBL 308P and 708P

Post by Defender »

Jajo you say most bass problems come from non perfect positioning of speakers.
What is your experience when you have a „seem to be perfect“ distance from the wall which is very musical but bass boomy. Is there another distance from the wall which is musical but without the bass boominess? Or does the bass boominess might go away with finding another distance between them. I also found already a very musical distance between them but it still has bass boominess.
Did it happen to you that you found more than one quasi sweet spot?
Lego
Very active member
Very active member
Posts: 1147
Joined: 2007-04-18 11:42
Location: glasgow

Re: JBL 308P and 708P

Post by Lego »

Defender wrote: 2022-01-21 14:43 Jajo you say most bass problems come from non perfect positioning of speakers.
What is your experience when you have a „seem to be perfect“ distance from the wall which is very musical but bass boomy. Is there another distance from the wall which is musical but without the bass boominess? Or does the bass boominess might go away with finding another distance between them. I also found already a very musical distance between them but it still has bass boominess.
Did it happen to you that you found more than one quasi sweet spot?
Have you tried turning the bass down ?
I know that tune
Defender
Very active member
Very active member
Posts: 1266
Joined: 2018-02-14 22:35

Re: JBL 308P and 708P

Post by Defender »

yes I did and I didn’t enjoy it as much. My conclusion is now when the bass is not tamed enough it might be not the optimal position. I positioned them now more far away from each other and the bass problems are away and the slight harshness in the upper frequencies also.

Moved from them from 1.45Meters to 1.70Meters distance. They are really special.
Post Reply