[haugejan]

I’ve upgraded my car with Earthquake SWS-8 sub and BSW Stage1. I’m planning to by a JL Audio HD900/5 amp connect the high level signal from the HU and OEM AMP for the sub to the HD900/5. The problem is that these signals are crossover, but I don’t know how. Anyone know what frequents the HU crossover the signal between the midrange/twitter and the sub?

If possible I don’t want to use a summing device, but use the OEM crossover from the HU

[VP Electricity]

The crossover frequency is around 100-160 Hz. There are different slopes and slightly different xover points. You don't have to do anything to sum them together for the system you describe. Sometimes I EQ boost and cut within the stopbands, but only when the 4" can handle it.

I don't think I have the RTA screenshots of the E60 any longer, sorry. It was a couple years ago...but I remember them.

[haugejan]

Originally Posted by VP Electricity

The crossover frequency is around 100-160 Hz. There are different slopes and slightly different xover points. You don't have to do anything to sum them together for the system you describe. Sometimes I EQ boost and cut within the stopbands, but only when the 4" can handle it.

I don't think I have the RTA screenshots of the E60 any longer, sorry. It was a couple years ago...but I remember them.

Thanks a lot!! I probably go for the JL 900/5 AMP

[VP Electricity]

I don't know if the amp can take the woofer output voltage cleanly... Technic might know. The balanced signal to the OEM amp from the HU might work, but you will have a dramatic voltage mismatch on the inputs.

As a fellow touring owner, let's see pics!

[haugejan]

Originally Posted by VP Electricity

I don't know if the amp can take the woofer output voltage cleanly... Technic might know. The balanced signal to the OEM amp from the HU might work, but you will have a dramatic voltage mismatch on the inputs.

As a fellow touring owner, let's see pics!

I’m planning to configure the AMP for high level (800mV – 8V) and use the high level from HU for the mid/tweeter (Should be max 7V) and use the low level balanced signal that is used for the sub AMP (I think this is a 5V signal) and then adjust the gain on the AMP to match the level. Do you think this would work?

Here is some picture of the upgrade so fare. I first tried with a Alpine PDX-5 amp, but that amp don’t accept high level so that was not a good solution:











The sub is installed:





The Alpine PDX-5 is connected to the Earthquake sub:



The BSW Stage 1 upgrade:





















Original compared to the BSW:

[Technic]

Originally Posted by haugejan

I’m planning to configure the AMP for high level (800mV – 8V) and use the high level from HU for the mid/tweeter (Should be max 7V) and use the low level balanced signal that is used for the sub AMP (I think this is a 5V signal) and then adjust the gain on the AMP to match the level. Do you think this would work?

I have some concerns about setting the HD switch to high level and using a low level balanced signal as inputs. I'm not quite sure that JL intent is to use that combination with any of their amps. You should ask JL if that is possible and if so, without any noise.

For sure, a Matrix line driver could be a better OEM interface to the HD. It accepts that particular combination of high level and low level balanced up to 13V peak and at the same time you can adjust/normalize the output level right there while the HD gains are at minimum for better noise/hiss control.

[haugejan]

Originally Posted by Technic

I have some concerns about setting the HD switch to high level and using a low level balanced signal as inputs. I'm not quite sure that JL intent is to use that combination with any of their amps. You should ask JL if that is possible and if so, without any noise.

For sure, a Matrix line driver could be a better OEM interface to the HD. It accepts that particular combination of high level and low level balanced up to 13V peak and at the same time you can adjust/normalize the output level right there while the HD gains are at minimum for better noise/hiss control.

I see your point. Just check the manual, and it looks like the HD900/5 amp has balanced signal on bought the high level and low level signal. Many player uses 4V low level signal so I assume that on those player you need to use the "High" mode. I think I’ll try with this amp and if it’s not working I’ll add a Matrix line driver/AudioControl LC6i
Here is the info about input mode from the manual:

“Input Voltage” Switch
A wide range of signal input voltages can be
accommodated by each of the HD900/5’s differentialbalanced
inputs (200mV – 8V RMS). This wide range
is split up into two sub-ranges, accessible via the
“Input Voltage” switch located next to the “Input
Mode” switch under the “General Setup” heading.
The “Low” position of the “Input Voltage”
switch selects an input sensitivity range between
200mV and 2V for all the amplifier channels. This
means that the “Input Sens.” rotary controls will
operate within that voltage window. If you are
using an aftermarket source unit, with preamplevel
outputs, this is most likely the position that
you will use (regardless of what voltage output
capability is claimed by the source unit).
The “High” position of the “Input Voltage”
switch selects an input sensitivity range between
800mV and 8V. This is for use with speaker-level
outputs from source units and small amplifiers
found in many OEM (factory-installed) systems.
To use speaker-level sources, splice the speaker
output wires of the source unit or small amplifier
onto a pair of RCA plugs for each input pair or use
the JL Audio ECS Speaker Wire to RCA adaptor
(XB-CLRAIC2-SW). It is not necessary (or
advisable) to use “Line Output Converters” with
your HD900/5.

[Technic]

Originally Posted by haugejan

“Input Voltage” Switch
A wide range of signal input voltages can be
accommodated by each of the HD900/5’s differentialbalanced
inputs (200mV – 8V RMS). This wide range
is split up into two sub-ranges, accessible via the
“Input Voltage” switch located next to the “Input
Mode” switch under the “General Setup” heading.
The “Low” position of the “Input Voltage”
switch selects an input sensitivity range between
200mV and 2V for all the amplifier channels. This
means that the “Input Sens.” rotary controls will
operate within that voltage window. If you are
using an aftermarket source unit, with preamplevel
outputs, this is most likely the position that
you will use (regardless of what voltage output
capability is claimed by the source unit).
The “High” position of the “Input Voltage”
switch selects an input sensitivity range between
800mV and 8V. This is for use with speaker-level
outputs from source units and small amplifiers
found in many OEM (factory-installed) systems.
To use speaker-level sources, splice the speaker
output wires of the source unit or small amplifier
onto a pair of RCA plugs for each input pair or use
the JL Audio ECS Speaker Wire to RCA adaptor
(XB-CLRAIC2-SW). It is not necessary (or
advisable) to use “Line Output Converters” with
your HD900/5.

Thanks, I did not read that .pdf section close enough... it looks like you will be OK by mixing both type of signals while using the High input level setting.