13 replies to this topic

[fenis]

Hey guys I'm looking at getting the Pioneer DEX P99RS as I want to play lossless files from an ipod with only 1 D/A conversion but I have a question about the EQ:

Is the 31band eq PER CHANNEL or only separate left/right? I'm going with a high end 2 way (7 inch seas w18nx in doors and scanspeak illuminator tweets in kicks) and to try and get more midbass impact coming from the front at high volumes I think the midbasses are going to need some eq boost at around 63-80hz. Now if the EQ is only separate L/R then this eq boosting will also boost these frequencies coming from the subwoofer which I DONT want.. But if I can individually boost 63-80hz on only the midbass channels then it should help with this impact coming from the front.

Cheers guys

Edited by fenis, 20 March 2011 - 09:44 PM.

[Pulse-R]

Only the Alpine H701 or Audison BitOne will do the separate EQ per output. None of the one-box units will do.

Even the Pioneer ODR has only 2 channel EQ's

Edited by Pulse-R, 20 March 2011 - 07:35 PM.

[fenis]

Any tips on getting more midbass output from the midbass speakers rather than from the sub with only L/R eq?

I'm thinking the only way with the P99 is to use a steep slope low pass filter for the sub plus maybe another low pass filter on top of that (using amp's crossover) to try to cancel out the boost in midbass frequencies on the sub.

[mosoto]

fenis, on 20 March 2011 - 08:52 PM, said:

Any tips on getting more midbass output from the midbass speakers rather than from the sub with only L/R eq?

I'm thinking the only way with the P99 is to use a steep slope low pass filter for the sub plus maybe another low pass filter on top of that (using amp's crossover) to try to cancel out the boost in midbass frequencies on the sub.

I have the the midbass running from 63Hz to 1.6kHz and the sub below 63Hz.
I get no midbass coming thru the subs.

Edited by mosoto, 20 March 2011 - 09:11 PM.

[fenis]

mosoto, on 20 March 2011 - 09:10 PM, said:

I have the the midbass running from 63Hz to 1.6kHz and the sub below 63Hz.
I get no midbass coming thru the subs.

Yeah but at high volumes do you still have up front impact? It's easy to have upfront bass but more challenging to have upfront bass IMPACT without large cone area midbass drivers.

Have a read of this thread on diyma to get more of an idea what I'm talking about:
Upfront bass - just an illusion?

Edited by fenis, 20 March 2011 - 09:49 PM.

[~Spyne~]

Simon is only half correct - yes the p99 is only L/R eq across all outputs, however the Eclipse cd7200 also has channel specific eq; 1 band for sub, 5 bands for mids, 5 bands for tweets.

[Matt VIP]

what EQ do you have on your amps? you may be able to use a single band to cover the frequencies you want to adjust. Otherwise, cross your sub lower with a steeper slope.

[Winno]

If your Seas midbasses have a decent xmax, run them full range all the way down to natural roll off down near 40Hz or whatever.
i.e. don't run them on any high pass filter/xover at all.
This will pull your bass forward and also give you a more impact and 'slam'.

You might also want to play with the phase and gain of your drivers too when tuning things up.
You don't say whether you're going to run a passive system or an active system although I suspect active is what you'll be going for.

It also should go without saying that you're putting your mids onto a solid mount into treated doors.

Edited by Winno, 21 March 2011 - 08:42 AM.

[fenis]

Matt VIP, on 21 March 2011 - 08:16 AM, said:

what EQ do you have on your amps? you may be able to use a single band to cover the frequencies you want to adjust. Otherwise, cross your sub lower with a steeper slope.

Actually I just thought of this I can use the bass boost on my arc 2300SE (can adjust both frequency and level) to boost only the midbass channels.

Winno, on 21 March 2011 - 08:37 AM, said:

If your Seas midbasses have a decent xmax, run them full range all the way down to natural roll off down near 40Hz or whatever.
i.e. don't run them on any high pass filter/xover at all.
This will pull your bass forward and also give you a more impact and 'slam'.

You might also want to play with the phase and gain of your drivers too when tuning things up.
You don't say whether you're going to run a passive system or an active system although I suspect active is what you'll be going for.

It also should go without saying that you're putting your mids onto a solid mount into treated doors.

Yep I'll be running full active and will definitely focus on making my doors as solid as possible (eg using aluminium tubing to stiffen up mounting area, modelling clay etc).

As for the xmax of the seas w18nx it's listed as 22mm. Not sure if want to let them run full range as it might muddy up the midrange and also they will be installed IB in the doors so won't have as much suspension control. Here are the specs:



On the freq response chart the thin line is the IB response - I thought in IB you lose heaps of midbass output below 100hz or am I wrong? And does cabin gain usually boost midbass as well?

Edited by fenis, 22 March 2011 - 10:20 AM.

[br85]

I'm am 100% sure that if you DO have a problem, it will be an acoustic, not an electrical one. You can't fix an acoustic problem with eq like that.

/Vagueness.

[muzzy66]

fenis, on 20 March 2011 - 08:52 PM, said:

Any tips on getting more midbass output from the midbass speakers rather than from the sub with only L/R eq?

Maybe a different midbass driver?

I've looked into a lot of different DIY drivers myself when I settled on the Revelators - the Seas were one of the drivers looked quite closly at, but they seem pretty mediocre for car use IMO. They have super low distorion below 160hz, but from my research they lack outright production down there. It seems their usable extension is merely average for a 6.5" (around 160hz before rolling off)and the very low Q also seems to make them quite poorly suited to a car door.

If you are really fixed on the Seas then I'd say that some in depth EQ would definatley be necessary in the midbass - if used in IB, all DIY drivers I've used have needed it..some more then others.

If you're going way, then unfortunately a CD7200 might be a serious option worth considering. It'san option I've looked into myself too once I get my finances under control - much as I dislike the ghastly look of the things, they are probably the best equipped unit for handling highly complex EQ needs spread over a limited bandwidth (with the HXD2 being next most suitable).

[muzzy66]

fenis, on 22 March 2011 - 10:11 AM, said:

As for the xmax of the seas w18nx it's listed as 22mm. Not sure if want to let them run full range as it might muddy up the midrange and also they will be installed IB in the doors so won't have as much suspension control. Here are the specs:

While this figure seems very impressive, it's really not as extreme as itseems.

Most companies list their xmax at linear, one way. The 22mm figure is maximum two-way. Linear two-way is 14mm, and that translates to probably 6mm - 7mm one-way linear. Really not much greater then other good midbass driversout there.

Zaph actually tested the Seas at 7mm xmax compared to 6.5mm for the Revelator, 6mm for the cheaper L18 and 5.5mm for the SB17 so this confirms it. Good xmax still for a 7" midbass, but the figures in the data sheet give off an impression that they have 2x-3x the xmax of other elite midbass drivers, which they really aren't.

Edited by muzzy66, 23 March 2011 - 08:52 PM.

[muzzy66]

Winno, on 21 March 2011 - 08:37 AM, said:

If your Seas midbasses have a decent xmax, run them full range all the way down to natural roll off down near 40Hz or whatever.
i.e. don't run them on any high pass filter/xover at all.
This will pull your bass forward and also give you a more impact and 'slam'.

I tend to find that 31hz or 40hz seem to be the sweet spot in most cases - because of the way the drivers react to cabin gain and IB.

Problem is that power handling is significnatly reduced when you cross this low - they will reach peak xmax off probably 15w-20w or input power. That's not to say they still can't go loud...just depends on your definition of loud!

[Pulse-R]

if you want more impact, you need better enclosure and /or bigger cones.

mine are in 15litre sealed enclosure, crossed at 180Hz, and have plenty of impact.