I have a couple of days off so I have done a wee experiment which I think turned out nicely.
The cabinets I have for the 8PR200 were tuned rather high as they were built to hand over to subs at 100hz but I changed the ports to tune the cab to 65hz and applied some EQ. It looks quite severe but this system is never pushed above a gentle stroll. This is just to have a running system until I do the bottom half.
My anechoic chamber while the wife is at work:
After very little tinkering the 8PR200 and Peerless DFM-2535 cross at 1000hz with an LR4:
Distortion flits from -45db to -50db when tested at 90db:
In room response after some very quick and light room correction:
The cabinets I have for the 8PR200 were tuned rather high as they were built to hand over to subs at 100hz but I changed the ports to tune the cab to 65hz and applied some EQ. It looks quite severe but this system is never pushed above a gentle stroll. This is just to have a running system until I do the bottom half.
My anechoic chamber while the wife is at work:
After very little tinkering the 8PR200 and Peerless DFM-2535 cross at 1000hz with an LR4:
Distortion flits from -45db to -50db when tested at 90db:
In room response after some very quick and light room correction:
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For the moment I treat the response of the "odd" driver as production tolerance and EQ the response out.
It´s probably best to evaluate if I like what I hear before exchanging that one driver.
Think so too! You should better think twice before changing your 8" for a 10".
This could maybe make a nice looking compact 2-way on stands or so. Or slap some extra wood onto the sides of your subs so they are same width and use those as stands.
Cheers guys!
Do keep us posted on the HF108R - I spoke to someone from Faital the other day and he said that they use the R to refer to 'refined'.
Yeah, I am surprised at the decent polars from this set up and did get me thinking what I could get out of the 8PR200 with the right sized box. This is a 16L cab with a 68mm ID pipe 155mm long. I've never been happy with the look of the current cabs in this house and want something more permenant so rebuilding could be an option.
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I have the HF108 without "R".
Haven´t done any more measurements in the meantime but gone ahead received 2 RS225-8 for mid/bass-duties.
This will be a big but slim bookshelf of about 40l.
Keep you posted.
I think I have settled on a 10". It is definitely overkill for this project but one of the things I always fail to mention when I start a project is that I generally like to keep thing open ended and future proof.
For instance, the house we are in is a small terraced London house but if ever there was a baby GrahamGraham we would need to find something larger and being aprudent prospective dad my first thoughts are with the sound system and having something large and flexible enough.
So, I think the Eighteen Sound 10W650 fits the bill for the following reasons:
- Lots of possibilities with the alignments.
- Relatively low MMS cmpared to competitors
- Smooth looking FR from datasheet
- A definite step up from what I have atm
Eighteen Sound - Professional loudspeakers
Speak now if anyone has any thoughts 🙂
Attached is a rough alignment from datasheet spec.
For instance, the house we are in is a small terraced London house but if ever there was a baby GrahamGraham we would need to find something larger and being aprudent prospective dad my first thoughts are with the sound system and having something large and flexible enough.
So, I think the Eighteen Sound 10W650 fits the bill for the following reasons:
- Lots of possibilities with the alignments.
- Relatively low MMS cmpared to competitors
- Smooth looking FR from datasheet
- A definite step up from what I have atm
Eighteen Sound - Professional loudspeakers
Speak now if anyone has any thoughts 🙂
Attached is a rough alignment from datasheet spec.
Attachments
Mms is commonly regarded as important for mid range reproduction, yet, there has never been a valid explanation that could serve as a foundation for the assumption, apart from some kitchen mathematics. I picked that up here: Driver for JBL 708-ish dimensioned 2-way
... and after reading fluids comment, added some more kitchen mathematics. They seem to verify your choice, but be aware of my subscript. One remark: the low end of the 18sound is rather deficient.
... and after reading fluids comment, added some more kitchen mathematics. They seem to verify your choice, but be aware of my subscript. One remark: the low end of the 18sound is rather deficient.
Thanks for the link, sheeple, I need to give it some deeper reading to digest or the number crunching! 🙂
My reckoning on the MMS comes from a post Marco made here: System Based Around JBL H9800 Horn
My interpretation is that a lower MMS makes for a driver that will have better facility to reproduce detail at lower SPL. I am sure I am oversimplifying it to the point of utter distortion though.
What leads you to th assumption re deficient bass response?
My reckoning on the MMS comes from a post Marco made here: System Based Around JBL H9800 Horn
My interpretation is that a lower MMS makes for a driver that will have better facility to reproduce detail at lower SPL. I am sure I am oversimplifying it to the point of utter distortion though.
What leads you to th assumption re deficient bass response?
Pure ignorance, I assume. I don't have in mind anymore what was your actual target (f6). I remember you wanted to use room gain. From most of the reviews i.e. at ASR I learned that physically room corrected systems (shelved bass) do not sound as full as a flat to low region like f6 @ 36, equalized to counter the room modes. This is the reason why I always look for a flat response in the first way, and then, the 18sound driver needs massive support (low Mms
).Marco's rule of thump can also be contrasted with the newest discussion about high Qms drivers, high Qms having been held responsible for good low level listening, too. It has been argued persuasively that this parameter only matters at driver's Fs The significance of high Qms..?
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They're one of the biggest driver manufacturers on the planet and do tons of custom designs, so I doubt you'd know that a given driver in (especially a) US made speaker is Eminence or not. If you or I go to them with a set of specs they can make it for us in small batches, I believe 50 is the minimum order.
I've been using this (6th order ported) in domestic and PA cabs for nearly 20y. Works exceptionally well.
I also have no doubt this will work very well, as Genelec and JBL did it with their two-way speakers. But Graham seems to have chosen another way, good looking wood work! Are the side mounted plywood planks downsized braces?
My point was that 6th order ported works well, and with that specific driver, based upon actual experience, many times, countering the no doubt theoretical claim that it was not a good approach.
I understand, this was specific to the driver. Anyhow, it works with others, too: heavily equalized in a ~ 40l box PHL 3411 but the results ... Genelec S360a
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I haven't just used it on the one driver and application. Maybe 20 over the years using both pro and domestic drivers and systems.
Been long enough in the professional market to recognize certain brands
I am familiar with Eminence's capabilities as well as MOQ
Obviously you can, and I have no doubt it can work.
But there are many other woofers out their without those compromises, so why would you go through the hassle?
Doesn't make any sense at all.
That being said, non-logical approach seems to be standard for some people here.
That is a fully general statement, not pointed at anyone here in particular at all nor the person I just replied to!